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This article is concerned with sample size determination methodology for prediction models. We propose to combine the individual calculations via learning‐type curves. We suggest two distinct ways of doing so, a deterministic skeleton of a learning curve and a Gaussian process centered upon its deterministic counterpart. We employ several learning algorithms for modeling the primary endpoint and distinct measures for trial efficacy. We find that the performance may vary with the sample size, but borrowing information across sample size universally improves the performance of such calculations. The Gaussian process‐based learning curve appears more robust and statistically efficient, while computational efficiency is comparable. We suggest that anchoring against historical evidence when extrapolating sample sizes should be adopted when such data are available. The methods are illustrated on binary and survival endpoints. [ABSTRACT FROM AUTHOR]

Previous studies have shown that surgical residents can safely perform a variation of complex abdominal surgeries when provided with adequate training, proper case selection, and appropriate supervision. Their outcomes are equivalent when compared to experienced board-certified surgeons. Our previously published training curriculum for robotic assisted minimally invasive esophagectomy already demonstrated a possible reduction in time to reach proficiency. However, esophagectomy is a technically challenging procedure and comes with high morbidity rates of up to 60%, making it difficult to provide opportunities to train surgical residents. We aimed to investigate if a surgical resident could safely perform complex esophageal surgery when a structured modular teaching curriculum is applied. A structured teaching program based on our previously published modular step-up approach was applied by two experienced board-certified esophageal surgeons. Our IRB-approved (Institutional Review Board) database was searched to identify all Ivor-Lewis esophagectomies performed by the selected surgical resident from August 2019 to July 2021. The cumulative sum method was used to analyze the learning curve of the surgical resident. Outcomes of patients operated by the resident were then compared to our overall cohort of open, hybrid, and robotic Ivor-Lewis esophagectomies from May 2016 to May 2020. The total cohort included 567 patients, of which 65 were operated by the surgical resident and 502 patients were operated by experienced esophageal cancer surgeons as the control group. For baseline characteristics, a significant difference for BMI (Body mass index) was observed, which was lower in the resident's group (25.5 kg/m2 vs. 26.8 kg/m2 (P  = 0.046). A significant difference of American Society of Anesthesiologists- and Eastern Cooperative Oncology Group-scores was seen, and a subgroup analysis including all patients with American Society of Anesthesiologists I and Eastern Cooperative Oncology Group 0 was performed revealing no significant differences. Postoperative complications did not differ between groups. The anastomotic leak rate was 13.8% in the resident's cohort and 12% in the control cohort (P  = 0.660). Major complications (Clavien-Dindo ≥ IIIb) occurred in 16.9% of patients in both groups. Oncological outcome, defined by harvested lymph nodes (35 vs. 32.33, P  = 0.096), proportion of lymph node compliant performed operations (86.2% vs. 88.4%, P  = 0.590), and R0-resection rate (96.9% vs. 96%, P  = 0.766), was not compromised when esophagectomies were performed by the resident. The resident completed the learning curves after 39 cases for the total operating time, 38 cases for the thoracic operating time, 26 cases for the number of harvested lymph nodes, 29 cases for anastomotic leak rate, and finally 58 cases for the comprehensive complication index. For postoperative complications, no significant difference was seen between patients operated in the resident group versus the control group, with a third of patients being discharged with a textbook outcome in both cohorts. Furthermore, no difference in oncological quality of the resection was found, emphasizing safety and feasibility of our training program. A structured modular step-up for training a surgical resident to perform complex esophageal cancer surgery can successfully maintain patient safety and outcomes. [ABSTRACT FROM AUTHOR]

Background: Cumulative sum (CUSUM) analysis is a valuable tool for quantifying the learning curve of surgical teams by detecting significant changes in operative length. However, there is limited research evaluating the learning curve of laparoscopic techniques in low-resource settings. The objective of this study is to evaluate the learning curve for laparoscopic appendectomy within a single surgical team in Senegal. Methods: This was a single-center prospective study conducted from May 1, 2018, to August 31, 2023 of patients who underwent laparoscopic appendectomy at a tertiary care institution in West Africa. The AAST classification was used to describe the severity of appendicitis. Parameters studied included age, sex, operative length, conversion rate, and postoperative outcomes. To quantify the learning curve, CUSUM analysis of operative length was performed. Results: A total of 81 patients were included. The mean age was 26.7 years (range 11–70 years) with a sex ratio of 1.9. Pre-operative severity according to AAST was Grade I in 75.4% (n = 61), Grade III in 7.4% (n = 6), Grade IV in 6.1% (n = 5), and Grade V in 11.1% (n = 9). Conversion occurred in 5 cases (6.1%). The average operative length was 76.8 min (range 30–180 min) and the average length of hospitalization was 2.7 days (range 1–13 days). Morbidity was observed in 3.7% (n = 3) and there were no deaths. The CUSUM analysis showed that a steady operative length was achieved after 28 procedures, with decreasing operative lengths thereafter. Conclusion: Surgeons in our setting overcame the learning curve for laparoscopic appendectomy after performing 28 procedures. Moreover, laparoscopic appendectomy is safe and feasible throughout the learning curve. CUSUM analysis should be applied to other laparoscopic procedures and individualized by surgical teams to improve surgical performance and patient outcomes in low-resource settings. [ABSTRACT FROM AUTHOR]

Background: New platforms for robotic surgery have recently become available for clinical use; however, information on the introduction of new surgical robotic platforms compared with the da Vinci™ surgical system is lacking. In this study, we retrospectively determined the safe introduction of the new "hinotori™" surgical robot in an institution with established da Vinci surgery using four representative digestive organ operations. Methods: Sixty-one patients underwent robotic esophageal, gastric, rectal, and pancreatic operations using the hinotori system in our department in 2023. Among these, 22 patients with McKeown esophagectomy, 12 with distal gastrectomy, 11 with high- and low-anterior resection of the rectum, and eight with distal pancreatectomy procedures performed by hinotori were compared with historical controls treated using da Vinci surgery. Results: The console (cockpit) operation time for distal gastrectomy and rectal surgery was shorter in the hinotori group compared with the da Vinci procedure, and there were no significant differences in the console times for the other two operations. Other surgical results were almost similar between the two robot surgical groups. Notably, the console times for hinotori surgeries showed no significant learning curves, determined by the cumulative sum method, for any of the operations, with similar values to the late phase of da Vinci surgery. Conclusions: This study suggests that no additional learning curve might be required to achieve proficient surgical outcomes using the new hinotori surgical robotic platform, compared with the established da Vinci surgery. [ABSTRACT FROM AUTHOR]

Biportal endoscopic spinal surgery (BESS) technique is a novel, useful, and minimally invasive therapeutic strategy for lumbar degenerative diseases, which has advantages over other surgical techniques. However, the degree of technical difficulty in learning BESS is controversial and not well established. This study aims to determine the learning curve of BESS technique through cumulative sum (CUSUM) analysis. A total of 144 consecutive patients who underwent BESS with lumbar decompressive discectomy between 2017 and 2023 were included. A retrospective bicenter study was performed. Three doctors with endoscopy experience employed the BESS technique for 51, 42, and 46 procedures, respectively. The CUSUM test of the 3 doctors showed adequate technical ability at the 45th, 41st, and 44th operations respectively. Two doctors without endoscopy experience gave up further use of BESS technique due to technical difficulties after initial attempt. The overall complication rates of the 3 surgeons using the BESS technique were 3.92% (n = 2), 6.82% (n = 3), and 2.17% (n = 1), respectively. Our study demonstrated that BESS is an effective treatment, and the learning curves of BESS for lumbar discectomy using CUSUM analysis were 41 ∼ 45 cases in trainees with endoscopic experience. Endoscopic experience contributes to the learning curve of the BESS technique. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the learning progress of less experienced readers in prostate MRI segmentation. Materials and methods: One hundred bi-parametric prostate MRI scans were retrospectively selected from the Göteborg Prostate Cancer Screening 2 Trial (single center). Nine readers with varying degrees of segmentation experience were involved: one expert radiologist, two experienced radiology residents, two inexperienced radiology residents, and four novices. The task was to segment the whole prostate gland. The expert's segmentations were used as reference. For all other readers except three novices, the 100 MRI scans were divided into five rounds (cases 1–10, 11–25, 26–50, 51–76, 76–100). Three novices segmented only 50 cases (three rounds). After each round, a one-on-one feedback session between the expert and the reader was held, with feedback on systematic errors and potential improvements for the next round. Dice similarity coefficient (DSC) > 0.8 was considered accurate. Results: Using DSC > 0.8 as the threshold, the novices had a total of 194 accurate segmentations out of 250 (77.6%). The residents had a total of 397/400 (99.2%) accurate segmentations. In round 1, the novices had 19/40 (47.5%) accurate segmentations, in round 2 41/60 (68.3%), and in round 3 84/100 (84.0%) indicating learning progress. Conclusions: Radiology residents, regardless of prior experience, showed high segmentation accuracy. Novices showed larger interindividual variation and lower segmentation accuracy than radiology residents. To prepare datasets for artificial intelligence (AI) development, employing radiology residents seems safe and provides a good balance between cost-effectiveness and segmentation accuracy. Employing novices should only be considered on an individual basis. Clinical relevance statement: Employing radiology residents for prostate MRI segmentation seems safe and can potentially reduce the workload of expert radiologists. Employing novices should only be considered on an individual basis. Key Points: • Using less experienced readers for prostate MRI segmentation is cost-effective but may reduce quality. • Radiology residents provided high accuracy segmentations while novices showed large inter-reader variability. • To prepare datasets for AI development, employing radiology residents seems safe and might provide a good balance between cost-effectiveness and segmentation accuracy while novices should only be employed on an individual basis. [ABSTRACT FROM AUTHOR]

Objectives: To assess the impact of the learning curve (LC) on perioperative and long‐term functional outcomes of a consecutive single‐centre series of robot‐assisted radical cystectomy with Padua intracorporeal orthotopic neobladder. Patients and Methods: Patients treated between 2013 and 2022 were included, with ≥1 year of follow‐up. The entire cohort was divided in tertiles. Categorical and continuous variables were compared. Joinpoint regression analysis was used to identify significant changes over the decade in linear slope of the 1‐year day‐ and night‐time continence. Uni‐ and multivariable Cox regression analyses identified predictors of day‐ and night‐time continence recovery. Day‐time continence was defined as 'totally dry' (no pads), night‐time continence as pad wetness ≤50 mL (one safety pad). Results: Overall, 200 patients were included. The mean hospital stay (P = 0.002) and 30‐day complications (P = 0.04) significantly reduced over time; the LC significantly impacted on Trifecta achievement (P < 0.001). The 1‐year day‐ and night‐time continence probabilities displayed a significant improving trend (day‐time continence annual average percentage change [AAPC] 11.45%, P < 0.001; night‐time continence AAPC 10.05%, P = 0.009). The LC was an independent predictor of day‐ (hazard ratio [HR] 1.008; P < 0.001) and night‐time continence (HR 1.004; P = 0.03) over time. Conclusion: Patients at the beginning of the LC had significantly longer hospitalisations, more postoperative complications, and lower Trifecta rates. At the 10‐year analyses, we observed a significant improving trend for both the 1‐year day‐ and night‐time continence probabilities, highlighting the crucial role of the LC. However, we are unable to assess the case volume needed to achieve a plateau in terms of day‐ and night‐time continence rates. [ABSTRACT FROM AUTHOR]

Objectives Methods Results Conclusion There is a lack of data on the number of surgeries required for endoscopic combined intrarenal surgery (ECIRS). Accordingly, we aimed to identify the learning curve for ECIRS performed by multiple surgeons.We included 296 patients who underwent ECIRS at our university hospital between 2016 and 2021. A learning curve for percutaneous nephrolithotomy side was calculated considering urology‐resident surgeons. The learning curve was retrospectively analyzed for surgical time, renal puncture time, stone‐free rate, and complications and corrected for age, body mass index, stone size, computed tomography value, cumulative number of surgeries, and stone location.This study included cases performed by 32 surgeons, including 30 residents and 2 attending surgeons. The median number of surgeries performed by the residents and attending surgeons prior to this study was 4.5 and 90, respectively. The median number of surgical procedures performed during the training period was seven. The surgical time of the residents decreased as the number of cases increased, reaching a median surgical time of 111 min for the attending surgeons after 16.4 cases. Renal puncture time was achieved in 20.1 cases. Complications related to renal access were observed in 13.0% (34 patients), Clavien–Dindo grade II in 1.9% (5 patients), and grade III or higher in 0.8% (2 patients). Comparing the first to fifth cases with the 21st and subsequent cases, the complication rate improved from 35% to 13%.Our study demonstrated that ECIRS training provided 16–20 cases with a learning curve to achieve acceptable surgical outcomes. [ABSTRACT FROM AUTHOR]

Background: We used transcatheter aortic valve implantation (TAVI) procedure time to investigate the association between surgical team maturity and outcome. Methods: Among patients who underwent TAVI between October 2015 and November 2019, those who had Sapien™ implanted with the transfemoral artery approach were included in the analysis. We used TAVI procedure time and surgery number to draw a learning curve. Then, we divided the patients into two groups before and after the number of cases where the sigmoid curve reaches a plateau. We compared the two groups regarding the surveyed factors and investigated the correlation between the TAVI procedure time and survey factors. Results: Ninety-nine of 149 patients were analysed. The sigmoid curve had an inflection point in 23.2 cases and reached a plateau in 43.0 cases. Patients in the Late group had a shorter operating time, less contrast media, less radiation exposure, and less myocardial escape enzymes than the Early group. Surgical procedure time showed the strongest correlation with the surgical case number. Conclusion: The number of cases required for surgeon proficiency for isolated Sapien™ valve implantation was 43. This number may serve as a guideline for switching the anesthesia management of TAVI from general to local anesthesia. [ABSTRACT FROM AUTHOR]

Objectives: To compare perioperative outcomes of patients treated with sutureless off-clamp robotic partial nephrectomy (sl-oc RAPN) by either a novice or an expert robotic surgeon at two different institutions. Methods: Data concerning two continuous series of patients with cT1-2N0M0 renal tumors treated with sl-oc RAPN either by a novice or an expert surgeon were extracted from prospectively populated institutional databases over the last 4 years. Perioperative outcomes as well as the baseline characteristics of patients and tumors were compared by using χ2 and Mann–Whitney tests for categorical and continuous variables, respectively. A 1:1 propensity match score analysis (PMSa) generated two homogeneous cohorts. Logistic regression analysis was performed to assess predictors of trifecta outcomes, defined as negative surgical margins, no Clavien–Dindo ≧ 3 grade complications, and no ≧ 30% postoperative eGFR reduction. Results: Overall, 328 patients were treated by an expert surgeon, while 40 were treated by a novice surgeon. After PMSa analysis, two cohorts of 23 patients each were generated, homogeneous for all baseline variables (p ≥ 0.07). Hospital stay was the only significantly different outcome observed between the two groups (5 days vs. 2 days; p < 0.001). No statistically significant differences were recorded when comparing trifecta outcomes (expert: 100% vs. novice: 87%; p = 0.07). In the logistic regression analysis, no statistically significant predictors of trifecta outcomes were recorded. Conclusions: sl-oc RAPN is a feasible and safe nephron sparing technique, even when performed by a novice robotic surgeon. [ABSTRACT FROM AUTHOR]

Background: Many cases of deep vein thrombosis (DVT) are diagnosed in the emergency department, and abbreviated lower extremity venous point-of-care ultrasound (POCUS) has already shown an accuracy comparable to that of specialists. This study aimed to identify the learning curve necessary for emergency medicine (EM) residents to achieve expertise-level accuracy in diagnosing DVT through a 3-point lower extremity venous POCUS. Methods: This prospective study was conducted at an emergency department between May 2021 and October 2022. Four EM residents underwent a one-hour POCUS training session and performed DVT assessments in participants with DVT symptoms or confirmed pulmonary embolism. POCUS was performed at three proximal lower extremity sites to evaluate the thrombi presence and vein compressibility, with results validated by specialized radiology ultrasound. Cumulative sum (CUSUM) and the Bush and Mosteller models were used to analyze the learning curve, while generalized estimating equations were used to identify factors affecting diagnostic accuracy. Results: 91 POCUS scans were conducted in 49 patients, resulting in 22% DVT confirmed by specialized venous ultrasound. In the CUSUM analysis, all four EM residents attained a 90% success rate at the common femoral vein, whereas only half achieved this rate when all three sites were considered. According to Bush and Mosteller models, 13–18 cases are required to attain 90–95% diagnostic accuracy. After 10–16 cases, the examination time for each resident decreased, and a 20% increase in examiner confidence was linked to a 2.506-fold increase in the DVT diagnosis accuracy. Conclusion: EM residents generally required 13–18 cases for 90–95% DVT diagnostic accuracy, but proficiency varied among individuals, particularly requiring more cases for regions outside the common femoral vein. [ABSTRACT FROM AUTHOR]

Background: Patient-specific aiming devices (PSAD) may improve precision and accuracy of glenoid component positioning in total shoulder arthroplasty, especially in degenerative glenoids. The aim of this study was to compare precision and accuracy of guide wire positioning into different glenoid models using a PSAD versus a standard guide. Methods: Three experienced shoulder surgeons inserted 2.5 mm K-wires into polyurethane cast glenoid models of type Walch A, B and C (in total 180 models). Every surgeon placed guide wires into 10 glenoids of each type with a standard guide by DePuy Synthes in group (I) and with a PSAD in group (II). Deviation from planned version, inclination and entry point was measured, as well as investigation of a possible learning curve. Results: Maximal deviation in version in B- and C-glenoids in (I) was 20.3° versus 4.8° in (II) (p < 0.001) and in inclination was 20.0° in (I) versus 3.7° in (II) (p < 0.001). For B-glenoid, more than 50% of the guide wires in (I) had a version deviation between 11.9° and 20.3° compared to ≤ 2.2° in (II) (p < 0.001). 50% of B- and C-glenoids in (I) showed a median inclination deviation of 4.6° (0.0°-20.0°; p < 0.001) versus 1.8° (0.0°-4.0°; p < 0.001) in (II). Deviation from the entry point was always less than 5.0 mm when using PSAD compared to a maximum of 7.7 mm with the standard guide and was most pronounced in type C (p < 0.001). Conclusion: PSAD enhance precision and accuracy of guide wire placement particularly for deformed B and C type glenoids compared to a standard guide in vitro. There was no learning curve for PSAD. However, findings of this study cannot be directly translated to the clinical reality and require further corroboration. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to investigate the learning curve of percutaneous endoscopic transforaminal discectomy (PETD) and interlaminar unilateral biportal endoscopic discectomy (UBED) in the treatment of lumbar disc herniation (LDH). Methods: Between 2018 and 2023, 120 consecutive patients with lumbar disc herniation (LDH) treated by endoscopic lumbar discectomy were retrospectively included. The PETD group comprised 87 cases, and the UBED group comprised 33 cases. Cumulative sum analysis was used to evaluate the learning curve, with the occurrence of complications or unresolved symptoms defined as surgical failure, and variables of different phases of the learning curve being compared. Results: The learning curve analysis identified the cutoff point at 40 cases in the PETD group and 15 cases in the UBED group. In the mastery phase, both PETD and UBED demonstrated a significant reduction in operation times (approximately 38 min for PTED and 49 min for UBED). In both PETD and UBED groups, the surgical failure rates during the learning and mastery phases showed no statistically significant differences. The visual analogue scale at the last follow-up was significantly lower than before surgery in both the PETD and UBED groups. Conclusion: PETD and UBED surgery are effective in the treatment of LDH with a low incidence of complications. However, achieving mastery in PETD necessitates a learning curve of 40 cases, while UBED requires a minimum of 15 cases to reach proficiency. [ABSTRACT FROM AUTHOR]

Background/Objectives: Total knee arthroplasty (TKA) is a frequent procedure in orthopedic surgery. Advances in TKA include the development of robotic-assisted systems. Training in raTKA entails a learning curve to achieve proficiency comparable to conventional manual TKA (maTKA). Methods: We conducted a prospective study of the learning curve in raTKA using the Robotic Surgical Assistant (ROSA) Knee System. The study included 180 patients (90 raTKAs; 90 maTKAs) and three surgeons (one with >15 years of experience in maTKA). The cumulative sum control chart method (CUSUM) was used to define the transition from the learning phase to the mastered phase in raTKA. Results: The learning curves were 43 cases (experienced surgeons) and 61 cases (all surgeons). Mean operative times for both phases in raTKA were longer than in maTKA (p < 0.001). In raTKA, operative times in the learning phase were longer compared to those in the mastered phase (p < 0.001). Operative times in the learning and mastered phases for all surgeons in raTKA were significantly longer compared to those in maTKA (p < 0.001); however, operative times of the experienced surgeon in the mastered phase of raTKA and in maTKA showed no differences. Conclusions: The learning curve in raTKA is dependent upon the surgeon's previous experience in maTKA. [ABSTRACT FROM AUTHOR]

Background: External ear canal exostoses are usually bilateral and broad-based, secondary to external ear canal chronic cold exposure, especially water. Objectives: The objectives were to analyze the influence of the surgeon's experience on the 3-year recurrence and on the complication. We also studied the influence of prolonged exposure to cold water on the incidence of recurrence. Material and Methods: This monocentric retrospective study included 98 ears operated for canalplasty between 2009 and 2016 by nine different operators including one senior, a junior, and seven beginner surgeons. Senior, Junior, and Beginner groups were compared. Results: 3-year recurrence rate was higher in the Beginner and Junior groups than in the Senior group (69% and 38% vs 18%, P =.001). Although there was a difference between the Beginner (69%) and Junior (38%) groups, it was not significant (P =.407). Among the recurrences, 48% had continued exposure to cold water while only 7% of the ears without recidivism were still exposed (P <.001, OR = 1.25 [4.4; 36.1]). The complication rates were similar between groups, concerning pain (8% vs 30% vs 12%), per procedure perforation (17% vs 10% vs 16%), scarring disorders (25% vs 20% vs 13%), and osteitis (8% vs 0% vs 1%). Hearing was unaffected. Conclusions: This is the first study evaluating the risk of recurrence of external ear canal exostoses after canalplasty based on the surgeon's experience. This risk of recurrence seems to decrease with the surgeon's experience. There was no difference in complication rates. [ABSTRACT FROM AUTHOR]

Objective: To report the learning curve of multiple operators for fusion magnetic resonance imaging (MRI) targeted biopsy and to determine the number of cases needed to achieve proficiency. Materials and Methods: All adult males who underwent fusion MRI targeted biopsy between February 2012 and July 2021 for clinically suspected prostate cancer (PCa) in a single centre were included. Fusion transrectal MRI targeted biopsy was performed under local anaesthesia using the Koelis platform. Learning curves for segmentation of transrectal ultrasonography (TRUS) images and the overall MRI targeted biopsy procedure were estimated with locally weighted scatterplot smoothing by computing each operator's timestamps for consecutive procedures. Non‐risk‐adjusted cumulative sum (CUSUM) methods were used to create learning curves for clinically significant (i.e., International Society of Urological Pathology grade ≥ 2) PCa detection. Results: Overall, 1721 patients underwent MRI targeted biopsy in our centre during the study period. The median (interquartile range) times for TRUS segmentation and for the MRI targeted biopsy procedure were 4.5 (3.5, 6.0) min and 13.2 (10.6, 16.9) min, respectively. Among the 14 operators with experience of more than 50 cases, a plateau was reached after 40 cases for TRUS segmentation time and 50 cases for overall MRI targeted biopsy procedure time. CUSUM analysis showed that the learning curve for clinically significant PCa detection required 25 to 45 procedures to achieve clinical proficiency. Pain scores ranged between 0 and 1 for 84% of patients, and a plateau phase was reached after 20 to 100 cases. Conclusions: A minimum of 50 cases of MRI targeted biopsy are necessary to achieve clinical and technical proficiency and to reach reproducibility in terms of timing, clinically significant PCa detection, and pain. [ABSTRACT FROM AUTHOR]

Background and Aims: In response to documented duodenoscope-related infectious outbreaks of multidrug-resistant organisms, the Food and Drug Administration has recommended a transition to duodenoscopes with innovative designs, including duodenoscopes with disposable components or fully disposable duodenoscopes. We aim to characterize the learning curve (LC) for a single-use disposable duodenoscope. Methods: We performed a retrospective analysis of a prospectively collected database from 31 patients who underwent ERCP by a single, experienced operator using the EXALT Model D® (Boston Scientific, Marlborough) disposable duodenoscope at a single tertiary referral center. The LC for this device was described by the number of cases needed to achieve proficiency using cumulative sum (CUSUM) analysis. Number of attempts to cannulate and time to cannulate the desired duct were assessed as separate endpoints. The overall mean number of attempts and overall mean time to cannulation were used as the target values in the respective CUSUM analyses. Proficiency was defined as the number of procedures where an inflection point was reached in the CUSUM graph. This observation indicates improving operator performance as shown by a decrease in the number of attempts and shortening of cannulation time after the defined number of procedures. Results: Overall, 31 patients underwent ERCP using the EXALT Model D disposable duodenoscope by a single experienced endoscopist. 6 (19%) patients had a native papilla and the majority of these procedures were classified as ASGE complexity level 2 or above. The procedure was completed using solely the disposable duodenoscope in 27 patients (87%), while a reusable duodenoscope was required for procedure completion in 4 patients (13%). The cross-overs were distributed evenly across the performance period. Procedure-related adverse events included: post-ERCP pancreatitis (3%), bleeding (3%) and no perforations. In the analyses of both endpoints, an inflection of the CUSUM curves is achieved at 10 cases, indicating sustained reduction of cannulation attempts and time to cannulation. Conclusion: Among experienced pancreaticobiliary endoscopists, approximately 10 ERCPs is the threshold whereby procedure-related factors including cannulation success and procedural time improves. Procedure-related adverse events are consistent with those expected with reusable duodenoscopes. The need to cross-over from single-use duodenoscope to reusable duodenoscope did not appear to be related to the learning curve, as they were evenly distributed across the study period. These results can be used to guide adoption of single-use duodenoscopes into clinical practice. [ABSTRACT FROM AUTHOR]

Purpose: To analyze the learning curves of ultrasound novices in fetal echocardiography during structured simulation-based ultrasound training (SIM-UT) including a virtual, randomly moving fetus. Methods: 11 medical students with minimal (< 10 h) prior obstetric ultrasound experience underwent 12 h of structured fetal echocardiography SIM-UT in individual hands-on sessions during a 6-week training program. Their learning progress was assessed with standardized tests after 2, 4, and 6 weeks of SIM-UT. Participants were asked to obtain 11 fetal echocardiography standard planes (in accordance with ISUOG and AHA guidelines) as quickly as possible. All tests were carried out under real life, examination-like conditions on a healthy, randomly moving fetus. Subsequently, we analyzed the rate of correctly obtained images and the total time to completion (TTC). As reference groups, 10 Ob/Gyn physicians (median of 750 previously performed Ob/Gyn scans) and 10 fetal echocardiography experts (median of 15,000 previously performed Ob/Gyn scans) were examined with the same standardized tests. Results: The students showed a consistent and steady improvement of their ultrasound performance during the training program. After 2 weeks, they were able to obtain > 95% of the standard planes correctly. After 6 weeks, they were significantly faster than the physician group (p < 0.001) and no longer significantly slower than the expert group (p = 0.944). Conclusion: SIM-UT is highly effective to learn fetal echocardiography. Regarding the acquisition of the AHA/ISUOG fetal echocardiography standard planes, the students were able to reach the same skill level as the expert group within 6 weeks. [ABSTRACT FROM AUTHOR]

Background: Several guidelines exist for minimally invasive pancreatoduodenectomy (MIPD) regarding its prerequisites and learning curve. However, these guidelines are based on the experience of the pioneers of MIPD; minimal data exist on the experience of the next generation of surgeons. The aim of this study was to compare the two surgeon types (veteran and junior) for MIPD in terms of immediate postoperative outcomes. Methods: The postoperative outcomes of 22 patients who underwent robot‐assisted pancreatoduodenectomy (RAPD) by a junior surgeon from July 2021 to December 2022 were retrospectively reviewed. The outcomes were compared with the initial postoperative outcomes and the contemporary postoperative outcomes of RAPD by a veteran surgeon. Results: In comparing the initial outcomes between the two surgeon types, the veteran surgeons showed a shorter operation time (junior surgeon vs. veteran surgeon: 606 ± 89 vs. 467 ± 77 min, p < 0.001). However, there was no significant difference in terms of postoperative outcomes, such as blood loss (300 [200–600] ml. vs. 200 [100–500] ml, p = 0.208), major complications (≥CDC IIIa: 4 (18.2%) vs. 4 (18.2%), p = 1.000), postoperative pancreatic fistula (POPF; ≥ISGPF Grade B: 2 (9.1%) vs. 3 (13.6%), p > 0.999), and length of hospital stay (18.0 ± 8.9 days vs. 18.3 ± 7.9 days, p = 0.915), between the two surgeon types. In addition, in a comparison of the contemporary outcomes, there was no significant difference in terms of postoperative outcome (complications: 4 (18.2%) vs 11 (11.1%), p = 0.580; POPF: 2 (9.1%) vs. 3 (3.0%), p = 0.484; length of hospital stay: 18.0 ± 8.9 vs. 15.0 ± 6.5 days, p = 0.065). Conclusion: The initial outcomes of MIPD by a well‐trained junior surgeon were found to be comparable to those of MIPD by a veteran surgeon. [ABSTRACT FROM AUTHOR]

Purpose: Minimally-invasive total gastrectomy (MITG) is associated with lower morbidity in comparison to open total gastrectomy but requires a learning curve (LC). We aimed to perform a pooled analysis of the number of cases required to surmount the LC (NLC) in MITG. Methods: A systematic review of PubMed, Embase, Scopus and the Cochrane Library from inception until August 2022 was performed for studies reporting the LC in laparoscopic total gastrectomy (LTG) and/or robotic total gastrectomy (RTG). Poisson mean (95% confidence interval [CI]) was used to determine the NLC. Negative binomial regression was performed as a comparative analysis. Results: There were 12 articles with 18 data sets: 12 data sets (n = 1202 patients) on LTG and 6 data sets (n = 318 patients) on RTG. The majority of studies were conducted in East Asia (94.4%). The majority of the data sets (n = 12/18, 66.7%) used non-arbitrary analyses. The NLC was significantly smaller in RTG in comparison to LTG [RTG 20.5 (95% CI 17.0–24.5); LTG 43.9 (95% CI 40.2–47.8); incidence rate ratio 0.47, p < 0.001]. The NLC was comparable between totally-laparoscopic total gastrectomy (TLTG) and laparoscopic-assisted total gastrectomy (LATG) [LATG 39.0 (95% CI 30.8–48.7); TLTG 36.0 (95% CI 30.4–42.4)]. Conclusions: The LC for RTG was significantly shorter for LTG. However existing studies are heterogeneous. [ABSTRACT FROM AUTHOR]

Background: Historically, pancreaticoduodenectomy (PD) has been performed via a laparotomy, but increasingly, laparoscopic and robotic platforms are being employed for PD. Laparoscopic PD has a steep surgeon specific learning curve and programmatic elements that must be optimized. These factors may limit a surgeon who is proficient at laparoscopic PD to develop a program at another institution. We hypothesize that the learning curve for a surgeon transferring a program to a second institution is shorter than the initial laparoscopic PD learning curve for the same surgeon. Methods: A retrospective review of patients who underwent laparoscopic PD for any indication at the first institution (FI) from 2012 to 2017 and the second institution (SI) from 2018 to 2021 was conducted. Standard statistical analysis was performed. The learning curve was identified using one-sided CUSUM analysis of operative times. Result: We identified 110 participants, 90 from the FI and 20 from the SI. More patients at the FI were diagnosed with periampullary adenocarcinoma on final pathology compared to the SI (65.6% vs 40.0%, P =.0132). FI operative times stabilized after the 25th laparoscopic PD and SI operative times stabilized after the 5th operation. No statistically significant difference was identified in postoperative complications. Conclusions: The learning curve and average operative time of an SI laparoscopic PD program was shorter than the initial learning curve for a single surgeon with comparable outcomes. This suggests that complex minimally invasive surgical programs can be safely transferred to another high-volume institution without significant loss of progress. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusion To determine the individual learning curves for cordocentesis in a low‐cost simulator for maternal‐fetal medicine (MFM) fellows.This observational, descriptive, educational, and prospective study was performed from July through November 2022. After an introductory course based on a standardized technique for cordocentesis, each second‐year MFM fellow who accepted to participate in the study performed this procedure using a low‐cost simulation model, and experienced operators supervised the cordocenteses. Learning curves were then created using cumulative sum analysis (CUSUM).Seven second‐year MFM fellows with no previous experience in cordocentesis accepted to participate in the study. A total of 2676 procedures were assessed. On average, residents performed 382 ± 70 procedures. The mean number of procedures to achieve proficiency was 369 ± 70, the overall success rate was 84.16%, and the corresponding failure rate was 15.84%. At the end of the study, all fellows were considered competent in cordocentesis. One fellow required 466 attempts to achieve competency, performing a total of 478 procedures, but the resident with the fewest attempts to reach competency required 219 procedures, completing 232 procedures. Some of the most frequent reasons for failed attempts included not reaching the indicated point for vascular access (20.99%) and being unable to retrieve the sample (69.10%).CUSUM analysis to assess learning curves, in addition to using low‐cost simulation models, helped to appraise individualized learning, allowing an objective demonstration of competency for cordocentesis among MFM fellows. [ABSTRACT FROM AUTHOR]

Objectives Methods Results Conclusions We investigated the background of patients who underwent contact laser vaporization of the prostate (CVP) surgery and the learning curve of the operators.A total of 207 patients who underwent CVP surgery for benign prostatic hyperplasia between August 2018 and March 2023 were included in this study. Patient background, perioperative results, pre‐ and postoperative urinary flow tests, and complications were collected retrospectively.We enrolled 12 doctors who were divided into expert (five doctors) and novice (seven doctors) groups based on the number of TURP experiences before CVP. The median patient age was 73 years (51–92 years) and prostate volume was 56 cc (15–190 cc) with no difference between the expert and novice groups. Complications included urinary retention (eight cases), hematuria (four), urinary tract infection (four), intraoperative perforation (two), and postoperative stricture (one). Both cases of intraoperative perforation occurred in the novice group. The expert group had a significantly shorter operative time (38 vs. 66 min) and a higher operative efficacy of prostate volume divided by operative time (1.43 vs. 0.88 cc/min). Postoperatively, IPSS, quality of life scores, and postvoid residual urine volume decreased, and maximal flow rate increased; however, there was no significant difference between the groups. The expert group showed stable operative time and operative efficacy after about five to eight cases, while the novice group showed stable after about 15 cases.Our findings suggest that CVP was safely performed at our hospital, and operators with limited experience in TURP can achieve stable perioperative results. [ABSTRACT FROM AUTHOR]

Background and Aims: Pancreaticoduodenectomy (PD) is a complex and high-skill demanding procedure often associated with significant morbidity and mortality. However, the results have improved over the past two decades. However, there is a paucity of research concerning the learning curve for PD. Our aim was to report the outcomes of 100 consecutive PDs representing a single surgeon's learning curve and to depict the factors that influenced the learning process. Methods: We reviewed the first 121 PDs performed at our academic center (2013–2019) by a single surgeon; 110 were PDs (5 laparoscopic and 105 open) and 11 were total PDs (1 laparoscopic and 10 open). Subsequent statistics was performed on the first 100 PDs, with attention paid to the learning curve and survival rate at 5 years. The data were analyzed comparing the first 50 cases (Group 1) to the last 50 cases (Group 2). Results: The most frequent histopathological tumor type was pancreatic ductal adenocarcinoma (50%). A total of 39% of patients had preoperative biliary drainage and 45% presented with positive biliary cultures. The preferred reconstruction technique included pancreaticogastrostomy (99%), in situ hepaticojejunostomy (70%), and precolic gastro-jejunal anastomosis (88%). Postoperative complications included biliary fistula (1%), pancreatic fistula (8%), pancreatic stump bleeding (4%), and delayed gastric emptying (13%). The mean operative time decreased after the first 50 cases (p < 0.001) and blood loss after 60 cases (p = 0.046). R1 resections lowered after 25 cases (p = 0.025). Vascular resections (17%) did not influence the rate of complications (p = 0.8). The survival rate at 5 years for pancreatic adenocarcinoma was 32.93%. Conclusions: Outcomes improve as surgeon experience increases, with proper training being the most important factor for minimizing the impact of the learning curve over the postoperative complications. Analyzing the learning curve from the perspective of a single surgeon is mandatory for accurate statistical results and interpretation. [ABSTRACT FROM AUTHOR]

Bacground: The aim of this study was to assess the learning curve of a novel seven-axis robot-assisted total hip arthroplasty (RaTHA) system. Methods: A total of 59 patients who underwent unilateral total hip arthroplasty at our institution from June 2022 to September 2022 were prospectively included in the study. In this randomized controlled clinical trial, robot-assisted THA (RaTHA) and Conventional THA (CoTHA) were performed using cumulative sum (CUSUM) analysis to evaluate the learning curve of the RaTHA system. The demographic data, preopera1tive clinical data, duration of operation, postoperative Harris Hip Score (HHS), postoperative Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and duration of operation between the learning stage and the proficiency stage of the RaTHA group were compared between the two groups. Results: The average duration of operation of the RaTHA group was increased by 34.73 min compared with the CoTHA group (104.26 ± 19.33 vs. 69.53 ± 18.38 min, p < 0.01). The learning curve of the RaTHA system can be divided into learning stage and proficiency stage, and the former consists of the first 13 cases by CUSUM analysis. In the RaTHA group, the duration of operation decreased by 29.75 min in the proficiency stage compared to the learning stage (121.12 ± 12.84 vs.91.37 ± 12.92, p < 0.01). Conclusions: This study demonstrated that the surgical team required a learning curve of 13 cases to become proficient using the RaTHA system. The duration of operation, total blood loss, and drainage gradually shortened (decreased) with the learning curve stage, and the differences were statistically significant. Trial registration: Number: ChiCTR2200061630, Date: 29/06/2022. [ABSTRACT FROM AUTHOR]

Background and Aim Methods Results Conclusion Tip‐in endoscopic mucosal resection (EMR) has a high en bloc resection rate for large colorectal neoplasms. However, non‐experts' performance in Tip‐in EMR has not been investigated. We investigated whether Tip‐in EMR can be achieved effectively and safely even by non‐experts.This retrospective study included consecutive patients who underwent Tip‐in EMR for 15–25 mm colorectal nonpedunculated neoplasms at a Japanese tertiary cancer center between January 2014 and December 2020. Baseline characteristics, treatment outcomes, learning curve of non‐experts, and risk factors of failing self‐achieved en bloc resection were analyzed.A total of 597 lesions were analyzed (438 by experts and 159 by non‐experts). The self‐achieved en bloc resection (69.8% vs 88.6%, P < 0.001) and self‐achieved R0 resection (58.3% vs 76.5%, P < 0.001) rates were significantly lower in non‐experts with <10 cases of experience than in experts, but not in non‐experts with >10 cases. Adverse event (P = 0.165) and local recurrence (P = 0.892) rates were not significantly different between experts and non‐experts. Risk factors of failing self‐achieved en bloc resection were non‐polypoid morphology (OR 3.4, 95% CI 1.6–7.3, P = 0.001), lesions with an underlying semilunar fold (OR 3.6, 95% CI 1.6–7.3, P < 0.001), positive non‐lifting sign (OR 3.1, 95% CI 1.2–8.0, P = 0.023), and non‐experts with an experience of ≤10 cases (OR 3.6, 95% CI 2.1–6.3, P < 0.001).The clinical outcomes of Tip‐in EMR for 15–25 mm lesions performed by non‐experts were favorable. [ABSTRACT FROM AUTHOR]

Background/Objectives: The absence of validated tools to assess the skill transfer from laparoscopy to robotic surgery remains an unsolved issue in the context of robot-assisted partial nephrectomy (RAPN). We aimed to describe and validate a novel proficiency score to critically evaluate the surgical quality of RAPN with the Hugo™ RAS System (Medtronic, Minneapolis, MN, USA). Methods: Between October 2022 and September 2023, 27 consecutive patients underwent off-clamp RAPN for localized renal tumors at our institution. To analyze the learning curve (LC), the cohort was chronologically divided into two phases of 6 months each. Proficiency was defined as the achievement of trifecta while maintaining a comparable intraoperative time in the interquartile range of laparoscopic partial nephrectomy performed by the same surgeon. A logistic binary regression model was built to identify predictors of proficiency achievement. Results: A proficiency score was achieved in 14 patients (74.1%). At univariable analysis, number of consecutive procedures > 12 (OR 13.7; 95%CI 2.05–21.1, p = 0.007), pathological tumor size (OR 0.92; 95%CI 0.89–0.99, p = 0.04) and essential blood hypertension (OR 0.16; 95%CI 0.03–0.82, p = 0.02) were found to be predictors of proficiency score. At multivariable analysis, after adjusting for potential confounding factors, number of consecutive procedures > 12 (OR 8.1; 95%CI 1.44–14.6, p = 0.03) was the only independent predictor of proficiency score achievement. Conclusions: Our results showed that the skills of an experienced laparoscopic surgeon are transferrable to the novel Hugo™ RAS System in the context of nephron-sparing surgery. Improved surgical quality may be expected after completing the first 12 consecutive procedures. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the novices' learning curves and proficiency level reached in laparoendoscopic single-site (LESS) surgery using three surgical training programs. Participants were randomly divided into three groups, who trained in a specific practice regimen for 12 days using a laparoscopic box simulator and three tasks. Group A trained in three stages using conventional laparoscopic surgery (CLS) with straight instruments, and LESS with straight and articulating instruments for four days each. Group B trained in two stages in LESS with straight and articulating instruments for six days each. Group C trained only in LESS with articulating instruments exclusively for all 12 days. Performance was registered daily during the 12 days to evaluate the participants' progress. Pre- and post-training analysis of the three groups showed significant differences in performance, denoting the significant improvement in their LESS skills, with no difference between the groups. Group C reached a high level of technical competence with their specific training program in LESS, obtaining a lower asymptote and slow learning rate. Specific training programs in LESS settings using articulated instruments showed a slower learning rate than the other programs but better proficiency in the technique with the best surgical performance. [ABSTRACT FROM AUTHOR]

Study Design.: A systematic review and meta-analysis. Objective.: The objective of this study is to examine the impact of the learning curve for endoscopic cervical foraminotomy for clinical outcomes and patient safety. Summary of Background Data.: Endoscopic cervical foraminotomy is a minimally invasive surgical technique emerging in the literature for surgical management of cervical radiculopathy without the use of open incision. The adoption of endoscopic cervical foraminotomy may be hindered by the learning curve, although no review and meta-analysis exists to date on the topic. Materials and Methods.: A systematic review and meta-analysis was performed using PubMed, CINAHL, and MEDLINE from database inception until July 11, 2023. Inclusion criteria were articles that examined endoscopic cervical foraminotomy, reported outcomes, and/or complications for endoscopic cervical spine surgery relevant to the learning curve and had full-text. A random effects meta-analysis was performed for outcomes and complications. Results.: A total of three articles (n=203 patients) were included from 792 articles initially retrieved. The learning curves from four surgeons were examined with a FWM 21 procedures until the competency phase. There was no significant difference in the postoperative hospitalization length (P =0.669), postoperative recovery room time (P =0.415), intraoperative blood loss (P =0.064), and total complication rates (10.9% vs. 1.2%, P =0.139) between endoscopic cervical foraminotomy procedures performed in the learning phase as compared with the competency phase of the learning curve. There was a significant decrease in operative time from the learning phase to the competency phase (P =0.005). Conclusion.: Competency was achieved on the learning curve for endoscopic cervical foraminotomy after about 21 procedures. There is no significant difference in postoperative hospitalization time, postoperative recovery room time, intraoperative blood loss, and complication rates between the learning phase and the competency phase of the learning curve for endoscopic cervical foraminotomy, noting the relatively small sample size of this study that may underpower this finding. [ABSTRACT FROM AUTHOR]

Background: Reports show a high complication rate when starting with the Direct Anterior Approach (DAA) in a supine position for hip arthroplasty. The DAA with the patient in lateral decubitus position may avoid this problem because it supposedly provides better visibility, especially on the femoral side. However, this approach did show a rather high complication rate during the adoption of the approach at 1 year follow up in our previous report. We were interested what the overall 7 year survival estimate would be and whether improvement could be seen with growing experience. Methods: A cohort of patients undergoing total hip arthroplasty right from the start of applying the DAA in lateral decubitus position was analysed. Results: In total 175 hip prostheses (162 patients) were evaluated. The 7-year survival estimate was 95.1%, 95 CI: 91.8–98.4%. In 6 of 8 revisions there was aseptic loosening of the stem. By dividing the cohort into 3 consecutive groups in time we did not see a significantly improving revision rate. Conclusions: In our experience, the adoption of the direct anterior approach in lateral decubitus position caused a relatively low 7-year survival estimate without an apparent decrease with growing experience, however given the low number of cases further research is needed to investigate the long-term risk of adopting a new approach. [ABSTRACT FROM AUTHOR]

Percutaneous endoscopic lumbar discectomy (PELD) presents a challenging learning curve, and the correlation between surgeon experience and clinical outcomes remains contentious. This retrospective study aimed to compare the outcomes of PELD performed by a single surgeon at beginner and experienced stages. Propensity score matching selected 150 patients (75 per group) with a minimum 3-year follow-up. Clinical and radiological outcomes, perioperative complications, and adverse events were assessed. Baseline characteristics, pain improvement, patient satisfaction, and radiological outcomes did not differ between the groups. However, operation time was longer in the beginner group than in the experienced group (57.5 min [IQR, 50.0–70.0] versus 50.0 min [IQR, 45.0–55.0], p < 0.001). The beginner group had higher perioperative complication rates (eight patients [10.7%] versus one patient [1.3%], with a hazard ratio of 8.836 [95% CI, 1.077–72.514], p = 0.034) and lower 3-year survival without adverse events (19 patients [25.3%] in the beginner group and 10 patients [13.3%] in the experienced group, p = 0.045). Our findings indicate that the clinical outcomes were more favorable in patients operated on at the experienced stage compared to those treated at the beginner stage. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the learning curve for donation after circulatory death (DCD) liver procurement. Methods: DCD liver procurements performed by a single surgeon (n = 36) were separated into two phases: the learning and established phases. Results: A cumulative sum analysis using the operative donor warm ischemia time (oWIT) and donor hepatectomy time (dHT) showed that ten and seven cases, respectively, were needed for stable surgical procedures. The established phase (n = 26, since Case 11) was likely to have a shorter oWIT (p = 0.06; 7.5 min vs. 9 min) and dHT (p = 0.09; 32 min vs. 37 min) than the learning phase. While the hospital stay was significantly shorter and donor age was older in the established phase (p = 0.04 and p < 0.01; 12 days vs. 41 days and 38 years vs. 24 years, respectively), the incidence rates of post-transplant complications such as early allograft dysfunction (p = 0.74) and vascular complications (p = 0.53) were similar. Conclusions: The learning curve for DCD liver procurement demonstrated that 10 cases were required to establish these techniques. The oWIT and dHT for DCD liver procurement can represent markers of operative efficiency. [ABSTRACT FROM AUTHOR]

Purpose: Limitations of standard-length femoral stems persist, including proximal-distal mismatch, non-ideal load transfer, loss of bone tissue, and perioperative fracture. Symbol® (Dedienne Santé, France) is a metaphyseal-engaging short-stem implant designed to address these issues in total hip arthroplasty (THA). While short stems have been well studied in selected and younger patients, it is unclear whether they offer advantages in an unselected population. We hypothesized that short femoral stems offer similar mid-term survivorship at five year minimum follow-up and function score to standard-length femoral stems, in an unselected patient population. Methods: We retrospectively reviewed a continuous unselected cohort of patients who undergone THA by one surgeon with a standard-length stem between November 2013 and October 2015, and a short stem between November 2015 and March 2017. We compared modified Harris Hip Score and Oxford Scores with a minimum follow-up of five years and procedural factors that could be associated with worse results with a short stem design. Results: There was no difference in survival rate between the two groups. Average Harris Hip Score and Oxford Scores at the last follow-up were comparable. A multivariate linear regression was performed to assess the relationship between modified Harrys Hip Score at five years post-operatively and the explanatory variables: age, body mass index, physical status score ASA (American Society of Anesthesiologists), and HHS pre-op. None was associated with the standard-length stem but for the short stem. Conclusion: Short-stem implants provide good survival rate at mid-term; nevertheless, a steep learning curve is necessary to optimize the metaphyseal filling of the implant, especially for osteoporotic bone. [ABSTRACT FROM AUTHOR]

Few studies evaluate the interplay of attending and resident learning curves in surgical education. Anastomotic time is known to be correlated with transplant outcomes in kidney transplantation. We aimed to evaluate the correlation between the combination of resident and attending experience and anastomotic time in kidney transplantation. We conducted a single-center retrospective cohort study of deceased donor kidney transplants from 2006 to 2019. To analyze the effect of attending and resident experience, dyads were classified as six combinations of early versus later practice attending and resident postgraduate year (PGY-2, PGY-3, and PGY-4/5). Attendings with less than 3 y of postfellowship practice were considered early practice. Linear mixed effects models tested the effects of attending experience, resident PGY, recipient body mass index, and technical operative characteristics (number of donor arteries, operative side) on anastomosis time. The final linear mixed effects model included 1306 transplants. Compared to later practice attendings with PGY-4/5 residents as reference, early practice attendings paired with PGY-2 or PGY-3 residents had longer anastomotic times (P ≤ 0.005) when adjusted for recipient body mass index, number of donor arteries, and transplant side. When PGY-4/5 residents were paired with early practice attendings, no difference in anastomotic time was demonstrated. When paired with later practice attendings, PGY-2 residents had longer anastomotic times (P < 0.001) while PGY-3 anastomotic times did not differ from PGY-4/5. This study demonstrates the correlation between trainee and attending experience jointly and anastomotic time, suggesting that pairing residents and attendings by experience may improve surgical training and potentially patient-related outcomes. [ABSTRACT FROM AUTHOR]

Retroperitoneoscopic adrenalectomy (RPA) has gained increasing popularity with its excellent perioperative outcomes and direct surgical access compared to other adrenalectomy approaches. We review perioperative outcomes of RPA by a specialized endocrine surgeon before and after expert intensive trainings (EITs), and to that of other laparoscopic adrenalectomy approaches at our center over a 9-year period, aiming to ascertain if RPA is worth the steep learning curve. One hundred twenty one adrenalectomies were performed between January 2014 to June 2022. Patient demographic, tumor characteristics, and perioperative outcomes were retrospectively reviewed. The primary endpoints included procedure duration, complications, and length of stay. Part I of the study examined the effect of EITs on RPA's learning curve, and part II compared these outcomes with that of the alternative approach, transabdominal lateral adrenalectomy (TLA). Both procedure duration and days in hospital markedly decreased after the two EITs for RPA. RPA resulted in a shorter procedure duration and hospital stay compared to TLA, and had lesser and milder intraoperative and postoperative complications compared to TLA. RPA results in safe and excellent outcomes, and offers additional benefit of direct surgical access, feasibility in patients with previous abdominal surgery, high body mass index, and multiple comorbidities. The steep learning curve can be overcome and shortened by EITs, motivating centers with specialized endocrine surgery to integrate RPA training into its curriculum, given its foreseeable rewarding outcomes. • RPA offers direct surgical access to the adrenal glands by bypassing the abdomen. • RPA's steep learning curve can be overcome in a short period, especially with expert intensive trainings (EITs). • RPA has significantly lesser and milder perioperative complications compared to TLA. • Specialized endocrine surgery centers to consider the integration of RPA training to its armamentarium. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate patient demographics, surgery characteristics, and patient-reported clinical outcomes related to the implementation of lumbar PTED in Denmark by surgeons novice to the PTED technique. Methods: All adult patients treated with a lumbar PTED from our first surgery in October 2020 to December 2021 were included. Data was generated by journal audit and telephone interview. Results: A total of 172 adult patients underwent lumbar PTED. Surgery duration was a median of 45.0 (35.0–60.0) minutes and patients were discharged a median of 0 (0–1.0) days after. Per operatively one procedure was converted to open microdiscectomy due to profuse bleeding. Post operatively one patient complained of persistent headache (suggestive of a dural tear), two patients developed new L5 paresthesia, and three patients had a newly developed dorsal flexion paresis (suggestive of a root lesion). Sixteen patients did not complete follow-up and 24 (14.0%) underwent reoperation of which 54.2% were due to residual disk material. Among the remaining 132 patients, lower back and leg pain decreased from 7.0 (5.0–8.5) to 2.5 (1.0–4.5) and from 8.0 (6.0–9.1) to 2.0 (0–3.6) at follow-up, respectively (p < 0.001). Additionally, 93.4% returned to work and 78.8% used less analgesics. Post hoc analysis comparing the early half of cases with the latter half did not find any significant change in surgery time, complication and reoperation rates, nor in pain relief, return to work, or analgesia use. Conclusion: Clinical improvements after lumbar PTED performed by surgeons novel to the technique are satisfactory, although the reoperation rate is high, severe complications may occur, and the learning curve can be longer than expected. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the learning curve and complications in unilateral biportal endoscopic transforaminal lumbar interbody fusion (ULIF) using the Cumulative Sum (CUSUM) analysis and Risk-adjusted Cumulative Sum (RA-CUSUM) analysis. Methods: This study retrospectively analyzed 184 consecutive patients who received ULIF in our hospital, including 104 males and 80 females. CUSUM analysis and RA-CUSUM analysis were used to evaluate the learning curve of ULIF based on the operation time and surgical failure rate, respectively. All postoperative complications were defined as surgical failure. Variables of different phases were compared based on the learning curve. Results: The CUSUM analysis showed the cutoff point for ULIF was 29 cases, and the RA-CUSUM analysis showed the cutoff point for ULIF was 41 cases. Operating time and hospital stay were significantly decreased as the learning curve progressed (P < 0.05). Visual analogue score (VAS) and Oswestry disability index (ODI) at the last follow-up were significantly lower than preoperatively. At the last follow-up, a total of 171 patients reached intervertebral fusion, with a fusion rate of 92.9% (171/184). A total of eleven complications were observed, and RA-CUSUM analysis showed that the incidence of complications in the early phase was 17.07% and in the late phase was 2.6%, with a significant difference (P < 0.05). Conclusion: ULIF is an effective minimally invasive lumbar fusion surgical technique. But a learning curve of at least 29 cases will be required to master ULIF, while 41 cases will be required to achieve a stable surgical success rate. [ABSTRACT FROM AUTHOR]

Background: Endoscopic spine surgery represents a significant advancement in the minimally invasive treatment of spinal disorders, promising reduced surgical invasiveness while aiming to maintain or improve clinical outcomes. This study undertakes a comprehensive review of the literature on endoscopic spine surgery, with a particular focus on cataloging and analyzing the range of complications, from common postoperative issues to more severe, casuistic outcomes like dural tears and nerve damage. Methods: Our methodology encompassed a detailed review of meta-analyses, prospective randomized trials, cohort studies, and case reports to capture a broad spectrum of complications associated with endoscopic spine techniques. The emphasis was on identifying both the frequency and severity of these complications to understand better the procedural risks. Results: The findings suggest that endoscopic spine surgery generally exhibits a lower complication rate compared to traditional surgical approaches. Nonetheless, the identification of specific, rare complications peculiar to endoscopic methods underscores the critical need for surgeons' advanced skills, continuous learning, and awareness of potential risks. Conclusions: Recognizing and preparing for the potential complications associated with the rapid adoption of endoscopic techniques is paramount to ensuring patient safety and improving surgical outcomes in minimally invasive spine surgery. [ABSTRACT FROM AUTHOR]

Introduction: The robotic-assisted (RATS) lobectomy learning curve is usually measured compared to an established videothoracoscopic (VATS) surgery program. The objective of our study is to compare the learning curves of both techniques. Methods: We performed an intention-to-treat analysis comparing the RATS vs. VATS lobectomies. Surgical time, conversions, complications, number of lymph nodes (LNs) and lymph node stations harvested, chest drainage duration, length of stay, readmissions, and 90-day mortality were compared between both groups. The learning curve was assessed using the CUSUM method. Results: RATS cases (30) and VATS cases (35) displayed no significant differences. The RATS learning curve was completed after 23 procedures while the VATS curve required 28 interventions. Complications appeared in four RATS procedures and in eight VATS patients. No differences in the number of LNs and harvested LN stations were reported. Four patients were readmitted in the RATS group, and eight in the VATS group. No 90-day postoperative mortality was observed in either group. The RATS group reported fewer chest tube days (3 (2–5) vs. 5 (4–5.8), p = 0.005) and hospital days (4 (3–6) vs. 5 (4–6), p = 0.023). Conclusions: The RATS curve appears shorter than the VATS curve. RATS lobectomies resulted in reduced chest tube duration and length of stay during the learning time period. [ABSTRACT FROM AUTHOR]

Purpose: Adequate position of the bone block during arthroscopic Latarjet procedure is critical for an optimal functional outcome. However, this procedure is complex with a long learning curve. Our aim was to compare the bone block position between a dedicated glenoid posterior instrumentation and suture button fixation versus an anterior screw fixation, on a postoperative computed tomography (CT) scan. Method: Seventy‐nine consecutive patients operated on for an anterior shoulder instability were included in this retrospective study. The same surgeon performed arthroscopically the Latarjet procedure either with an anterior drilling and screw fixation (Group A), or with a specific posterior glenoid guide pin, a posterior drilling, and a suture cortical button fixation (Group B). Evaluations were made by two independent observers. The position was evaluated by CT scan in the axial and sagittal planes. Learning curves with operative time, complications and clinical outcomes were assessed at a minimum of 2 years of follow‐up. Results: Thirty‐five patients were included in Group A and 44 in Group B. In Group A, 27 bone blocks were flush (87.1%) and 38 in Group B (92.7%) (p < 0.01). In Group A, 72% of the bone block height was below the equator and 76%, in Group B (ns). The mean operating time was 123 ± 32.5 min in Group A and 95 ± 34.1 min in Group B (p < 0.0001). At the final follow‐up, the mean aggregate Rowe score was respectively 94.6 ± 10.4 and 93.1 ± 9.8 points in Groups A and B. The mean aggregate Walch–Duplay score was respectively 94.2 ± 11.6 and 93.4 ± 10.6 points in Groups A and B. There were 11 complications (31.4%) in Group A and five complications (11.3%) in Group B (ns). Conclusion: The arthroscopic Latarjet procedure with a posterior drilling guided system and suture‐button fixation allows more precise positioning in the axial plane than with anterior drilling and screw fixation. This posterior‐guided procedure could reduce intraoperative and short‐term complications. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

Background: Critical care nurses are vital in the care of patients with life-threatening illnesses in intensive care units. To optimize their effectiveness, it is crucial to enhance their proficiency in professional care techniques. Implementing evidence-based training standards can improve nurses' knowledge, skills, and attitudes, ultimately enhancing healthcare services for patients. Aim/purpose: The aim of this study protocol is to outline a series of quasi-experimental, non-randomized, single-group studies that assess the impact of standardized training courses on the development of competencies in diverse care techniques for critical care nurses. Methodology: A comprehensive checklist will be created to evaluate nurses' professional qualifications in the specific care techniques under investigation. This checklist will be used during three expert panel sessions for each study. Nurses will then undergo theoretical and practical training to enhance their competence in implementing these techniques. To assess the training effectiveness, each nurse's competency level will be evaluated before, during, and after the training using a checklist to track their learning curve. Results: This study will use the learning curve model to determine the optimal number of repetitions required for novice intensive care unit nurses to attain a satisfactory level of competence in each targeted care technique after training. Conclusion: These findings could standardize nursing education practices and optimize skill practice frequency, leading to improved quality of education in the field. Trial registration: This study is also registered at U.S. National Library of Medicine under "Clinicaltrials.gov" identifier NCT02830971, https://www.clinicaltrials.gov/ct2/show/NCT02830971, first date registered 13/07/2016 and last updated on 15/04/2021. [ABSTRACT FROM AUTHOR]

Background: Laparoscopic totally extraperitoneal (TEP) inguinal hernia repair (IHR) reduces risk of injury to intraperitoneal structures. Balloon dissection is more costly and has theoretical risk of injury to the surrounding structures compared with telescopic dissection (TD). This study aims to evaluate the learning curve (LC) for TEP IHR with TD of a single surgeon. Methods: This is a 3-year retrospective cohort study from January 2020 to December 2022 on patients who underwent elective laparoscopic TEP unilateral IHR with TD. Exclusion criteria were recurrent inguinal hernia. Cumulative sum (CUSUM) analysis was performed to evaluate the number of cases required to surmount the LC, that is, NLC for operating time (OT) and open conversion. One way analysis of variance was used to perform groupwise comparison. Results: There were 69 patients who underwent laparoscopic TEP unilateral IHR with TD. The median age was 58.0 years (range 24.0–80.0) and body mass index was 23.0 (range 18.6–30.0). Majority of the hernia was indirect (n = 48, 69.6%). The median OT was 70 minutes (range 35–210). Three cases (4.3%) had open conversion. One-year recurrence was 4.2% (n = 1/24). CUSUM analysis showed improvement in OT after the eighth case. However, this was followed by multiple inflection points with no apparent stabilization in OT. Pairwise comparison showed a decrease in OT between cases 18–36 and cases 37–54. There was no incidence of open conversion until the 56th case. Conclusion: Laparoscopic TEP IHR using TD is safe in the absence of a practor. A minimum of 36 cases is required to surmount the initial LC. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to assess the degree of interest in robot-assisted spine surgery (RASS) among residents and to investigate the learning curve for beginners performing robotic surgery. Methods: We conducted a survey to assess awareness and interest in RASS among young neurosurgery residents. Subsequently, we offered a hands-on training program using a dummy to educate one resident. After completing the program, the trained resident performed spinal fusion surgery with robotic assistance under the supervision of a mentor. The clinical outcomes and learning curve associated with robotic surgery were then analyzed. Results: Neurosurgical residents had limited opportunities to participate in spinal surgery during their training. Despite this, there was a significant interest in the emerging field of robotic surgery. A trained resident performed RASS under the supervision of a senior surgeon. A total of 166 screw insertions were attempted in 28 patients, with 2 screws failing due to skiving. According to the Gertzbein-Robbins classification, 85.54% of the screws were rated as grade A, 11.58% as grade B, 0.6% as grade C, and 1.2% as grade D. The clinical acceptance rate was approximately 96.99%, which is comparable to the results reported by senior experts and time per screw statistically significantly decreased as experience was gained. Conclusion: RASS can be performed with high accuracy within a relatively short timeframe, if residents receive adequate training. [ABSTRACT FROM AUTHOR]

As part of creating a beautiful smile, aesthetic dental rehabilitation plays an important role. Regarding aesthetic analy-sis in the context of oral rehabilitation and treatment predictability, Digital Smile Design (DSD), mainly through plat-forms like SmileCloud®, provides invaluable resources. Our prospective study aimed to examine the relationship be-tween the clinical experience of dental practitioners and their proficiency in using DSD (SmileCloud). Additionally, the study assessed the association between previsualization scores and the category of respondents in terms of their connec-tion to the field of dentistry (laypeople, dental students, and dentists). The study included 11 subjects for whom three different dental practitioners (a 2nd and a 6th-year dental student and a 2nd-year resident doctor in Prosthodontics) created a DSD using SmileCloud. The DSDs were evaluated in an online survey regarding tooth colour, shape, and over-all smile appearance. A number of 220 responses have been collected from 48 dentists, 86 dental students and 86 lay-people. The DSD created by the 2nd year resident doctor in Prosthodontics has received significantly higher scores for tooth shape and overall smile appearance (p<0.05), as well as for the design (p<0.05) and design*respondent (p<0.05) variables. The practitioner's clinical experience considerably impacted aesthetic dental rehabilitation tools, which means there is always a learning curve involved. [ABSTRACT FROM AUTHOR]

The computed tomography scans of patients who underwent posterior instrumentation for thoracolumbar vertebral fractures were retrospectively reviewed. The aim of this study is to present a single surgeon's experience in the placement of pedicular screws in the thoracic, lumbar, and sacral spine using the two-way fluoroscopy-assisted freehand technique. The directions of screw malposition were classified as anterior, medial, lateral, superior, and inferior; screws with malposition in more than one direction were recorded. Patients' neurological symptoms were recorded and their compatibility with the direction and amount of screw malposition was assessed. The effect of surgical experience on thoracic, lumbar, and sacral pedicle screw placement and the amount of screw experience required for correct pedicle screw placement were investigated. The study evaluated 1112 pedicle screws in 147 patients with thoracolumbar fractures. Screw malposition was found in 206 (18.52%) screws. Medial malposition was found to be statistically higher in the lumbar spine (p<0.001). A significant correlation was found between inferior malposition and neurological deficit (p=0.012). Thoracic and sacral pedicle screw malposition was statistically higher than lumbar (p<0.001). It was found that 386 pedicle screws were required for the learning curve in lumbar fractures (p=0.004). Surgical experience is an important factor in correct screw placement. It was found that 386 pedicle screws were required for the learning curve in the lumbar spine. [ABSTRACT FROM AUTHOR]

Background: Robot-assisted surgery has been rapidly adopted. It is important to define the learning curve to inform credentialling requirements, training programs, identify fast and slow learners, and protect patients. This study aimed to characterize the hospital learning curve for common robot-assisted procedures. Study design: This cohort study, using administrative health data for Ontario, Canada, included adult patients who underwent a robot-assisted radical prostatectomy (RARP), total robotic hysterectomy (TRH), robot-assisted partial nephrectomy (RAPN), or robotic portal lobectomy using four arms (RPL-4) between 2010 and 2021. The association between cumulative hospital volume of a robot-assisted procedure and major complications was evaluated using multivariable logistic models adjusted for patient characteristics and clustering at the hospital level. Results: A total of 6814 patients were included, with 5230, 543, 465, and 576 patients in the RARP, TRH, RAPN, and RPL-4 cohorts, respectively. There was no association between cumulative hospital volume and major complications. Visual inspection of learning curves demonstrated a transient worsening of outcomes followed by subsequent improvements with experience. Operative time decreased for all procedures with increasing volume and reached plateaus after approximately 300 RARPs, 75 TRHs, and 150 RPL-4s. The odds of a prolonged length of stay decreased with increasing volume for patients undergoing a RARP (OR 0.87; 95% CI 0.82–0.92) or RPL-4 (OR 0.77; 95% CI 0.68–0.87). Conclusion: Hospitals may adopt robot-assisted surgery without significantly increasing the risk of major complications for patients early in the learning curve and with an expectation of increasing efficiency. [ABSTRACT FROM AUTHOR]

Learning minimally invasive suturing can be challenging, creating a barrier to further implementation, especially with the development of easier methods. Nevertheless, mastering intracorporeal knot tying is crucial when alternative techniques prove inadequate. Therefore, the minimally invasive surgery (MIS) suturing skills of MIS experts are compared with a group of novices during their learning curve on a simulator. The novice participants repeatedly performed the intracorporeal suturing task on the EoSim MIS simulator (up to a maximum of 20 repetitions). The experts (>50 MIS procedures and advanced MIS experience) completed the same task once. The first and last exercises of the novices and the expert tasks were all blindly recorded and assessed by two independent assessors using the Laparoscopic Suturing Competency Assessment Tool (LS-CAT). Additionally, objective assessment parameters, "time" and "distance", using instrument tracking, were collected. The scores of the experts were then compared with the novices. At the end of the training, novices significantly outperformed the experts on both the expert assessment (LS-CAT: 16.8 versus 26.8, P = 0.001) and objective parameters (median time: 190 s versus 161 s, P < 0.001; median distance: 6.1 m versus 3.6 m, P < 0.001). Although the experts showed slightly better performance than the novices during their first task, the difference was not significant on the expert assessment (LS-CAT experts 16.8, novices 20.5, P = 0.057). Our findings underscore the significance of continued MIS suturing training for both residents and surgeons. In this study, trained novices demonstrated a significant outperformance of experts on both quantitative and qualitative outcome parameters within a simulated setting. [ABSTRACT FROM AUTHOR]

Introduction: Laparoscopic liver resection is a challenging surgical procedure that may require prolonged operation time, particularly during the learning curve. Operation time significantly decreases with increasing experience; however, prolonged operation time may significantly increase the risk of postoperative complications. Aim: To assess whether prolonged operation time over the benchmark value influences short-term postoperative outcomes after laparoscopic liver resection. Material and methods: A retrospective cohort study based on data from the National Polish Registry of Minimally Invasive Liver Surgery was performed. A total of 197 cases consisting of left lateral sectionectomy (LLS), left hemihepatectomy (LH), and right hemihepatectomy (RH) with established benchmark values for operation time were included. Data about potential confounders for prolonged operation time and worse short-term outcomes were exported. Results: Most cases (129; 65.5%) were performed during the learning curve, while the largest rate was observed in LLS (57; 78.1%). Median operation time exceeded the benchmark value in LLS (Me = 210 min) and LH (Me = 350 min), while in RH the benchmark value was exceeded in 39 (44.3%) cases. Textbook outcomes were achieved in 138 (70.1%) cases. Univariate analysis (OR = 1.11; 95% CI: 0.61-2.06; p = 0.720) and multivariate analysis (OR = 1.16; 95% CI: 0.50-2.68; p = 0.734) did not reveal a significant impact of prolonged surgery on failing to achieve a textbook outcome. Conclusions: Prolonging the time of laparoscopic liver resection does not significantly impair postoperative results. There is no reason related to the patients' safety to avoid prolonging the time of laparoscopic liver resection over the benchmark value. [ABSTRACT FROM AUTHOR]

Objective: Presently, no study has compared the clinical outcomes of minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) with bilateral decompression via the unilateral approach (BDUA) and Open-TLIF with bilateral decompression for degenerative lumbar diseases (DLD). We aimed to compare the clinical outcomes of through Mis-TLIF combined with BDUA and Open-TLIF with bilateral decompression for the treatment of DLD, and reported the learning curve of the procedure of MIS-TLIF with BDUA. Methods: We retrospectively analyzed the prospectively collected data of consecutive DLD patients in the two groups from January 2016 to January 2020. Results: The operative time (OT) was significantly longer in the Mis-TLIF group (n = 113) than in the Open-TLIF group (n = 135). The postoperative drainage volume (PDV) and length of stay (LOS) were significantly higher in the Open-TLIF group than in the Mis-TLIF group. Additionally, the complication rate was significantly higher in the Open-TLIF group than in the Mis-TLIF group (14.8% vs. 6.2%, P = 0.030), while there was no significant difference in the reoperation and adjacent segment disease rates between the two groups. There were no significant differences in back pain and leg pain Numerical Rating Scale (NRS) scores and Oswestry Disability Index (ODI) between the two groups preoperatively, at discharge, and 2 years postoperatively. Patients in both groups showed significant improvements in NRS scores and ODI scores after surgery. OT was negatively correlated with the number of surgeries performed (P < 0.001, r = −0.43). The learning curve of Mis-TLIF with BDUA was steep, with OT tapered to steady state in 43 cases. Conclusion: Compared with Open-TLIF with bilateral decompression, Mis-TLIF with BDUA can achieve equivalent clinical outcomes, lower PDV and LOS, and lower complication rates. Although this procedure took longer, it could be a viable alternative for the treatment of DLD after a steep learning curve. [ABSTRACT FROM AUTHOR]

Aims: We report 30-day, 1-year, and 3-year outcomes for a new TAVR programme that used five different transcatheter heart valve (THV) systems. Methods: From 2014 to 2020, 122 consecutive patients with severe aortic stenosis (AS) received TAVR based on the Heart Team decision. Outcomes were analysed for the whole study population and in addition the first 63 patients (Cohort A, 2014 to 2019) were compared to the last 59 patients (Cohort B, 2019 to 2020). Outcomes included VARC-2 definitions and device performance assessed via transthoracic echocardiography by independent high-volume investigators. Results: The mean patient age was 77.9 ± 6.1 years old, and 48 (39.3%) were male. The mean logistic Euroscore II was 4.2 ± 4.5, and the mean STS score was 6.9 ± 4.68. The systems used were as follows: Medtronic Corevalve Evolute R/PRO (82 patients—67.2%); Abbott Portico (13—10.6%); Boston Scientific Lotus (10—8.2%); Meril Myval (11—9%); and Boston Scientific Neo Accurate (6—5%). Access was transfemoral (95.9% of patients); surgical cut down (18% vs. percutaneous 77.8%); subclavian (n = 2); trans-axillary (n = 2); and direct aorta (n = 1). VARC-2 outcomes were as follows: device success rate 97.5%; stroke rate 1.6%; major vascular complication 3.3%; permanent pacemaker implantation 12.4%. At discharge, the incidences of grade I and II aortic regurgitation were 39.95 and 55.5%, respectively. At one year, all-cause mortality was 7.4% without admissions for valve-related dysfunction. The 3-year all-cause mortality and all-stroke rates were 22.9% and 4.1%, respectively. Between the 1-year and 3-year follow-ups, valve-related dysfunction was detected in three patients; one had THV system endocarditis that led to death. There was a remarkable but statistically non-significant decrease in mortality from Cohort A to Cohort B [four (6.3%) vs. one patient (1.7%), p = 0.195] and major vascular complications occurred at a significantly higher rate in the Cohort B [zero (0%) vs. four (6.8% patient, p = 0.036)]. Overall, we found that using multiple devices was safe and allowed for a learning team to achieve a high device success rate from the beginning (97.5%). Conclusions: TAVR with different THV systems showed acceptable early and mid-term outcomes for survival, technical success, and valve-related adverse events in high-risk patients with significant AS, even in the learning curve phase. [ABSTRACT FROM AUTHOR]