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Introduction: Currently, the impact of body mass index (BMI) on the outcomes of laparoscopic liver resections (LLR) is poorly defined. This study attempts to evaluate the impact of BMI on the peri-operative outcomes following laparoscopic left lateral sectionectomy (L-LLS). Methods: A retrospective analysis of 2183 patients who underwent pure L-LLS at 59 international centers between 2004 and 2021 was performed. Associations between BMI and selected peri-operative outcomes were analyzed using restricted cubic splines. Results: A BMI of >27kg/m2 was associated with increased in blood loss (Mean difference (MD) 21 mls, 95% CI 5–36), open conversions (Relative risk (RR) 1.13, 95% CI 1.03–1.25), operative time (MD 11 min, 95% CI 6–16), use of Pringles maneuver (RR 1.15, 95% CI 1.06–1.26) and reductions in length of stay (MD -0.2 days, 95% CI -0.3 to −0.1). The magnitude of these differences increased with each unit increase in BMI. However, there was a “U” shaped association between BMI and morbidity with the highest complication rates observed in underweight and obese patients. Conclusion: Increasing BMI resulted in increasing difficulty of L-LLS. Consideration should be given to its incorporation in future difficulty scoring systems in laparoscopic liver resections.

Background Laparoscopic redo resections for colorectal metastases are poorly investigated. This study aims to explore long-term results after second, third, and fourth resections. Material and methods Prospectively updated databases of primary and redo laparoscopic liver resections in six European HPB centers were analyzed. Procedure-related overall survival after first, second, third, and fourth resections were evaluated. Furthermore, patients without liver recurrence after first liver resection were compared to those with one redo, two or three redo, and patients with palliative treatment for liver recurrence after first laparoscopic liver surgery. Survival was calculated both from the date of the first liver resection and from the date of the actual liver resection. In total, 837 laparoscopic primary and redo liver resections performed in 762 patients were included (630 primary, 172 first redo, 29 second redo, and 6 third redo). Patients were bunched into four groups: Group 1—without hepatic recurrence after primary liver resection (n = 441); Group 2—with liver recurrence who underwent only one laparoscopic redo resection (n = 154); Group 3—with liver recurrence who underwent two laparoscopic redo resections (n = 29); Group 4—with liver recurrence who have not been found suitable for redo resections (n = 138). Results No significant difference has been found between the groups in terms of baseline characteristics and surgical outcomes. Rate of positive resection margin was higher in the group with palliative recurrence (group 4). Five-year survival calculated from the first liver resection was 67%, 62%, 84%, and 7% for group 1, 2, 3, and 4, respectively. Procedure-specific 5-year overall survival was 50% after primary laparoscopic liver resection, 52% after the 1st reoperation, 52% after the 2nd, and 40% after the 3rd reoperation made laparoscopic. Conclusions Multiple redo recurrences can be performed laparoscopically with good long-term results. Liver recurrence does not aggravate prognosis as long as the patient is suitable for reoperation.

Background Despite the recent worldwide dissemination of laparoscopic liver surgery, no high-level evidence supports the oncologic safety of this approach. Objective To evaluate long-term oncologic outcomes after laparoscopic versus open liver resection in patients with colorectal metastases. Design A single-center, assessor-blinded, randomized controlled trial (OSLO-COMET [Oslo Randomized Laparoscopic Versus Open Liver Resection for Colorectal Metastases Trial]). (ClinicalTrials.gov: NCT01516710). Setting Oslo University Hospital, the only provider of liver surgery for the 3 million inhabitants of southeastern Norway. Participants Patients with resectable colorectal liver metastases were randomly assigned to have open or laparoscopic liver resection. Intervention From February 2012 to January 2016, a total of 280 patients were included in the trial (laparoscopic surgery: n = 133; open surgery: n = 147). Measurements The primary outcome was postoperative morbidity within 30 days. Five-year rates of overall and recurrence-free survival were predefined secondary end points. Results At a median follow-up of 70 months, rates of 5-year overall survival were 54% in the laparoscopic group and 55% in the open group (between-group difference, 0.5 percentage point [95% CI, -11.3 to 12.3 percentage points]; hazard ratio, 0.93 [CI, 0.67 to 1.30]; P = 0.67). Rates of 5-year recurrence-free survival were 30% in the laparoscopic group and 36% in the open group (between-group difference, 6.0 percentage points [CI, -6.7 to 18.7 percentage points]; hazard ratio, 1.09 [CI, 0.80 to 1.49]; P = 0.57). Limitation The trial was not powered to detect differences in secondary end points and was not designed to address a noninferiority hypothesis for survival outcomes. Conclusion In this randomized trial of laparoscopic and open liver surgery, no difference in survival outcomes was found between the treatment groups. However, differences in 5-year overall survival up to about 10 percentage points in either direction cannot be excluded. This trial should be followed by pragmatic multicenter trials and international registries. Primary funding source The South-Eastern Norway Regional Health Authority.

Traditionally, patients with large liver tumors (≥ 50 mm) have been considered for anatomic major hepatectomy. Laparoscopic resection of large liver lesions is technically challenging and often performed by surgeons with extensive experience. The current study aimed to evaluate the surgical and oncologic safety of laparoscopic parenchyma-sparing liver resection in patients with large colorectal metastases.Patients who primarily underwent laparoscopic parenchyma-sparing liver resection (less than 3 consecutive liver segments) for colorectal liver metastases between 1999 and 2019 at Oslo University Hospital were analyzed. In some recent cases, a computer-assisted surgical planning system was used to better visualize and understand the patients' liver anatomy, as well as a tool to further improve the resection strategy. The surgical and oncologic outcomes of patients with large (≥ 50 mm) and small ( 50 mm) tumors were compared. Multivariable Cox-regression analysis was performed to identify risk factors for survival.In total 587 patients met the inclusion criteria (large tumor group, n = 59; and small tumor group, n = 528). Median tumor size was 60 mm (range, 50-110) in the large tumor group and 21 mm (3-48) in the small tumor group (p 0.001). Patient age and CEA level were higher in the large tumor group (8.4 μg/L vs. 4.6 μg/L, p 0.001). Operation time and conversion rate were similar, while median blood loss was higher in the large tumor group (500 ml vs. 200 ml, p 0.001). Patients in the large tumor group had shorter 5 year overall survival (34% vs 49%, p = 0.027). However, in the multivariable Cox-regression analysis tumor size did not impact survival, unlike parameters such as age, ASA score, CEA level, extrahepatic disease at liver surgery, and positive lymph nodes in the primary tumor.Laparoscopic parenchyma-sparing resections for large colorectal liver metastases provide satisfactory short and long-term outcomes.

Introduction: Laparoscopic resection of the hepatic caudate lobe (LRCL) requires a high level of expertise due to its challenging anatomical area. Only case reports, case series, and single-center cohort studies have been published. The aim of this study was to assess the safety and feasibility of this laparoscopic procedure. Methods: A multicenter retrospective cohort study including all patients who underwent LRCL in 4 high-volume hepatobiliary units between January 2000 and May 2018 was performed. Perioperative, postoperative, and survival outcomes were assessed. Postoperative morbidity was stratified according to the Clavien-Dindo classification with severe complications defined by grade III or more. The Kaplan-Meier method was used for survival analysis. Results: A total of 32 patients were included, including 22 (68.8%) with colorectal liver metastasis (CRLM), one (3.1%) with cholangiocarcinoma, four (12.5%) with other malignancies, and five (15.6%) with symptomatic benign lesions. Simultaneous colorectal and/or additional liver resection was performed in 20 (62.5%) patients. The median (IQR) operative time was 155 (121–280) minutes, blood loss was 100 (50–275) ml, conversion rate was 9.4% (n = 3), severe complications were observed in 2 patients (6.3%), and median (range) length of hospital stay was 3 [1–39] days. No 90-day postoperative mortality was noticed. The median (IQR) follow-up for the CRLM group was 14 [10–23] months. Five-year overall survival rate was 82% in this subgroup. Small interinstitutional differences were observed without major impact on surgical outcomes. Conclusion: LRCL is safe and feasible when performed in high-volume centers. Profound anatomical knowledge, advanced laparoscopic skills, and mastering intraoperative ultrasound are essential. No major interinstitutional differences were ascertained.

The role of laparoscopy in the treatment of intrahepatic cholangiocarcinoma (ICC) remains unclear. This multicenter study examined the outcomes of laparoscopic liver resection for ICC. Patients with ICC who had undergone laparoscopic or open liver resection between 2012 and 2019 at four European expert centers were included in the study. Laparoscopic and open approaches were compared in terms of surgical and oncological outcomes. Propensity score matching was used for minimizing treatment selection bias and adjusting for confounders (age, ASA grade, tumor size, location, number of tumors and underlying liver disease). Of 136 patients, 50 (36.7%) underwent laparoscopic resection, whereas 86 (63.3%) had open surgery. Median tumor size was larger (73.6 vs 55.1 mm, p = 0.01) and the incidence of bi-lobar tumors was higher (36.6 vs 6%, p < 0.01) in patients undergoing open surgery. After propensity score matching baseline characteristics were comparable although open surgery was associated with a larger fraction of major liver resections (74 vs 38%, p < 0.01), lymphadenectomy (60 vs 20%, p < 0.01) and longer operative time (294 vs 209 min, p < 0.01). Tumor characteristics were similar. Laparoscopic resection resulted in less complications (30 vs 52%, p = 0.025), fewer reoperations (4 vs 16%, p = 0.046) and shorter hospital stay (5 vs 8 days, p < 0.01). No differences were found in terms of recurrence, recurrence-free and overall survival. Laparoscopic resection seems to be associated with improved short-term and with similar long-term outcomes compared with open surgery in patients with ICC. However, possible selection criteria for laparoscopic surgery are yet to be defined.

Background Traditionally, patients with large liver tumors (≥ 50 mm) have been considered for anatomic major hepatectomy. Laparoscopic resection of large liver lesions is technically challenging and often performed by surgeons with extensive experience. The current study aimed to evaluate the surgical and oncologic safety of laparoscopic parenchyma-sparing liver resection in patients with large colorectal metastases. Methods Patients who primarily underwent laparoscopic parenchyma-sparing liver resection (less than 3 consecutive liver segments) for colorectal liver metastases between 1999 and 2019 at Oslo University Hospital were analyzed. In some recent cases, a computer-assisted surgical planning system was used to better visualize and understand the patients’ liver anatomy, as well as a tool to further improve the resection strategy. The surgical and oncologic outcomes of patients with large (≥ 50 mm) and small ( Results In total 587 patients met the inclusion criteria (large tumor group, n = 59; and small tumor group, n = 528). Median tumor size was 60 mm (range, 50–110) in the large tumor group and 21 mm (3–48) in the small tumor group (p p p p = 0.027). However, in the multivariable Cox-regression analysis tumor size did not impact survival, unlike parameters such as age, ASA score, CEA level, extrahepatic disease at liver surgery, and positive lymph nodes in the primary tumor. Conclusion Laparoscopic parenchyma-sparing resections for large colorectal liver metastases provide satisfactory short and long-term outcomes. Graphical abstract

Despite many developments, postoperative bile leakage (POBL) remains a relatively common postoperative complication after laparoscopic liver resection (LLR) and open liver resection (OLR). Previous studies regarding the incidence and clinical impact of POBL have mainly focused on patients undergoing OLR. The aim of this study is to compare the incidence and clinical impact of POBL between patients undergoing LLR and OLR in a large international multicenter cohort using a propensity score matched analysis.

Most treatments for cancer cause a decline in patients' health-related quality of life (HRQoL). Limiting this decline is a universal goal for healthcare providers. Using minimally invasive instead of open surgical techniques might be one way to achieve this. The aim of this study was to compare postoperative HRQoL after open and laparoscopic liver resection.This was a predefined substudy of an RCT comparing open with laparoscopic liver resection. Patients with colorectal liver metastases were assigned randomly to open or laparoscopic parenchyma-sparing liver resection. HRQoL was assessed with the Short Form 36 questionnaire at baseline, and 1 and 4 months after surgery.A total of 280 patients were randomized, of whom 273 underwent surgery (129 laparoscopic, 144 open); 682 questionnaires (83.3 per cent) were available for analysis. One month after surgery, patients in the laparoscopic surgery group reported reduced scores in two HRQoL domains (physical functioning and role physical), whereas those in the open surgery group reported reduced scores in five domains (physical functioning, role physical, bodily pain, vitality and social functioning). Four months after surgery, HRQoL scores in the laparoscopic group had returned to preoperative levels, whereas patients in the open group reported reduced scores for two domains (role physical and general health). The between-group difference was statistically significant in favour of laparoscopy for four domains after 1 month (role physical, bodily pain, vitality and social functioning) and for one domain after 4 months (role physical).Patients assigned to laparoscopic liver surgery reported better postoperative HRQoL than those assigned to open liver surgery. For role limitations caused by physical health problems, patients in the laparoscopic group reported better scores up to 4 months after surgery. Registration number: NCT01516710 ( http://www.clinicaltrials.gov).La mayoría de los tratamientos para el cáncer causan una disminución de la calidad de vida relacionada con la salud (health-related quality of life, HRQoL) de los pacientes. Limitar este declive es un objetivo universal para los proveedores de atención médica. El uso de técnicas quirúrgicas mínimamente invasivas en lugar de abiertas podría ser una forma de lograrlo. El objetivo de este estudio fue comparar la HRQoL postoperatoria después de la resección hepática abierta y laparoscópica. MÉTODOS: Se trata de un subestudio predefinido de un ensayo aleatorizado y controlado que comparó la resección hepática abierta con la laparoscópica. Los pacientes con metástasis hepáticas colorrectales se asignaron aleatoriamente al grupo de resección hepática con preservación de parénquima por vía abierta o por vía laparoscópica. La HRQoL se evaluó con el cuestionario abreviado SF-36 en el momento basal y al cabo de 1 y 4 meses después de la cirugía.Un total de 280 pacientes fueron aleatorizados, de los cuales 273 se sometieron a cirugía (129 = laparoscópica, 144 = abierta) y hubo 682 cuestionarios (83%) disponibles para el análisis. Un mes después de la cirugía, los pacientes del grupo de cirugía laparoscópica presentaron puntuaciones reducidas en dos items de HRQoL (función física y rol físico), mientras que los pacientes del grupo de cirugía abierta presentaron puntuaciones reducidas en cinco items (función física, rol físico, dolor corporal, vitalidad y función social). Cuatro meses después de la cirugía, el grupo de cirugía laparoscópica había vuelto a los niveles preoperatorios de la HRQoL, mientras que los pacientes del grupo de cirugía abierta presentaron puntuaciones reducidas para dos items (función física y salud general). La diferencia entre los grupos fue estadísticamente significativa a favor de la laparoscopia para cuatro items después de un mes de la cirugía (rol físico, dolor corporal, vitalidad y función social) y para un ítem (rol físico) después de cuatro meses. CONCLUSIÓN: Los pacientes asignados a cirugía hepática laparoscópica presentaron mejor HRQoL postoperatoria que los pacientes asignados a cirugía hepática abierta. Para las limitaciones de roles causadas por problemas físicos de salud, los pacientes de cirugía laparoscópica presentaron mejores puntuaciones a los cuatro meses tras la intervención quirúrgica.

Background Laparoscopic liver surgery has evolved to become a standard surgical approach in many specialized centers worldwide. In this study we present the evolution of laparoscopic liver surgery at a single high-volume referral center since its introduction in 1998. Methods Patients who underwent laparoscopic liver resection (LLR) between August 1998 and December 2018 at the Oslo University Hospital were analyzed. Perioperative outcomes were compared between three time periods: early (1998 to 2004), middle (2005 to 2012) and recent (2013–2018). Results Up to December 2020, 1533 LLRs have been performed. A total of 1232 procedures were examined (early period, n = 62; middle period, n = 367 and recent period, n = 803). Colorectal liver metastasis was the main indication for surgery (68%). The rates of conversion to laparotomy and hand-assisted laparoscopy were 3.2% and 1.4%. The median operative time and blood loss were 130 min [interquartile range (IQR), 85–190] and 220 ml (IQR, 50–600), respectively. The total postoperative complications rate was 20.3% and the 30-day mortality was 0.3%. The median postoperative stay was two (IQR, 2–4) days. When comparing perioperative outcomes between the three time periods, shorter operation time (median, from 182 to 120 min, p p = 0.023), decreased rate of conversions to laparotomy (from 8 to 3%) and shorter postoperative hospital stay (median, from 3 to 2 days, p Conclusion During the last two decades, the indications, the number of patients and the complexity of laparoscopic liver procedures have expanded significantly. Initially being an experimental approach, laparoscopic liver surgery is now safely implemented across our unit and has become the method of choice for surgical treatment of most liver tumors.

In laparoscopic liver resection, surgeons conventionally rely on anatomical landmarks detected through a laparoscope, preoperative volumetric images and laparoscopic ultrasound to compensate for the challenges of minimally invasive access. Image guidance using optical tracking and registration procedures is a promising tool, although often undermined by its inaccuracy. This study evaluates a novel surgical navigation solution that can compensate for liver deformations using an accurate and effective registration method. The proposed solution relies on a robotic C-arm to perform registration to preoperative CT/MRI image data and allows for intraoperative updates during resection using fluoroscopic images. Navigation is offered both as a 3D liver model with real-time instrument visualization, as well as an augmented reality overlay on the laparoscope camera view. Testing was conducted through a pre-clinical trial which included four porcine models. Accuracy of the navigation system was measured through two evaluation methods: liver surface fiducials reprojection and a comparison between planned and navigated resection margins. Target Registration Error with the fiducials evaluation shows that the accuracy in the vicinity of the lesion was 3.78 ± 1.89 mm. Resection margin evaluations resulted in an overall median accuracy of 4.44 mm with a maximum error of 9.75 mm over the four subjects. The presented solution is accurate enough to be potentially clinically beneficial for surgical guidance in laparoscopic liver surgery.

Background Based on excellent outcomes from high-volume centres, laparoscopic liver resection is increasingly being adopted into nationwide practice which typically includes low-medium volume centres. It is unknown how the use and outcome of laparoscopic liver resection compare between high-volume centres and low-medium volume centres. This study aimed to compare use and outcome of laparoscopic liver resection in three leading European high-volume centres and nationwide practice in the Netherlands. Method An international, retrospective multicentre cohort study including data from three European high-volume centres (Oslo, Southampton and Milan) and all 20 centres in the Netherlands performing laparoscopic liver resection (low-medium volume practice) from January 2011 to December 2016. A high-volume centre is defined as a centre performing >50 laparoscopic liver resections per year. Patients were retrospectively stratified into low, moderate- and high-risk Southampton difficulty score groups. Results A total of 2425 patients were included (1540 high-volume; 885 low-medium volume). The median annual proportion of laparoscopic liver resection was 42.9 per cent in high-volume centres and 7.2 per cent in low-medium volume centres. Patients in the high-volume centres had a lower conversion rate (7.4 versus 13.1 per cent; P Conclusion High-volume expert centres had a sixfold higher use of laparoscopic liver resection, less conversions, and shorter hospital stay, as compared to a nationwide low-medium volume practice. Stratification into Southampton difficulty score risk groups identified some differences but largely outcomes appeared better for high-volume centres in each risk group.

Objective: To assess the risk factors associated with R1 resection in patients undergoing OLS and LLS for CRLMs. Background: The clinical impact of R1 resection in liver surgery for CRLMs has been continuously appraised, but R1 risk factors have not been clearly defined yet. Methods: A cohort study of patients who underwent OLS and LLS for CRLMs in 9 European high-volume referral centers was performed. A multivariate analysis and the receiver operating characteristic curves were used to investigate the risk factors for R1 resection. A model predicting the likelihood of R1 resection was developed. Results: Overall, 3387 consecutive liver resections for CRLMs were included. OLS was performed in 1792 cases whereas LLS in 1595; the R1 resection rate was 14% and 14.2%, respectively. The risk factors for R1 resection were: the type of resection (nonanatomic and anatomic/nonanatomic), the number of nodules and the size of tumor. In the LLS group only, blood loss was a risk factor, whereas the Pringle maneuver had a protective effect. The predictive size of tumor for R1 resection was >45 mm in OLS and >30 mm in LLS, > 2 lesions was significative in both groups and blood loss >350 cc in LLS. The model was able to predict R1 resection in OLS (area under curve 0.712; 95% confidence interval 0.665 – 0.739) and in LLS (area under curve 0.724; 95% confidence interval 0.671 – 0.745). Conclusions: The study describes the risk factors for R1 resection after liver surgery for CRLMs, which may be used to plan better the perioperative strategies to reduce the incidence of R1 resection during OLS and LLS.

Background Laparoscopic distal pancreatectomy (LDP) is a safe procedure, but its role in resection of large pancreatic lesions has been questioned. Methods Patients who underwent LDP for pancreatic solitary tumors in 1997–2017 were included in this study. The patients were divided into three groups in accordance with tumor size

Laparoscopic liver resection demands expertise and a long learning curve. Resection of the posterosuperior segments is challenging, and there are no data on the learning curve. The aim of this study was to evaluate the learning curve for laparoscopic resection of the posterosuperior segments.A cumulative sum (CUSUM) analysis of the difficulty score for resection was undertaken using patient data from four specialized centres. Risk-adjusted CUSUM analysis of duration of operation, blood loss and conversions was performed, adjusting for the difficulty score of the procedures. A receiver operating characteristic (ROC) curve was used to identify the completion of the learning curve.According to the CUSUM analysis of 464 patients, the learning curve showed an initial decrease in the difficulty score followed by an increase and, finally, stabilization. More patients with cirrhosis or previous surgery were operated in the latest phase of the learning curve. A smaller number of wedge resections and a larger number of anatomical resections were performed progressively. Dissection using a Cavitron ultrasonic surgical aspirator and the Pringle manoeuvre were used more frequently with time. Risk-adjusted CUSUM analysis showed a progressive decrease in operating time. Blood loss initially increased slightly, then stabilized and finally decreased over time. A similar trend was found for conversions. The learning curve was estimated to be 40 procedures for wedge and 65 for anatomical resections.The learning curve for laparoscopic liver resection of the posterosuperior segments consists of a stepwise process, during which accurate patient selection is key.La resección hepática laparoscópica exige experiencia y una larga curva de aprendizaje. La resección de los segmentos posterosuperiores (PS) es un reto, y no hay datos acerca de la curva de aprendizaje (learning curve, LC). El objetivo de este estudio fue evaluar la LC de la resección laparoscópica de los segmentos PS. MÉTODOS: Se realizó un análisis CUSUM de la puntuación de dificultad (difficulty score, DS) de la resección en pacientes de 4 centros especializados. La técnica CUSUM se ajustó al riesgo (risk-adjusted CUSUM, RA-CUSUM) para el tiempo operatorio, la pérdida de sangre y las conversiones a cirugía abierta ajustando según la DS de los procedimientos. Se utilizó una curva ROC para identificar el momento en el que se consideró que la LC había sido completada.De acuerdo con el análisis CUSUM de los 464 pacientes incluidos, se observó una DS baja al inicio, que posteriormente se fue incrementando hasta llegar a una estabilización. En la última fase de la LC se operaron más pacientes con cirrosis o cirugía previa. De forma progresiva se fueron reduciendo el número de resecciones hepáticas en cuña y aumentando el de resecciones anatómicas. A lo largo del tiempo se introdujo el CUSA y la maniobra de Pringle con mayor frecuencia. El RA-CUSUM mostró una reducción progresiva del tiempo operatorio. La pérdida de sangre inicialmente aumentó ligeramente, luego se estabilizó y finalmente disminuyó con el tiempo. Una tendencia similar se observó para las conversiones. La LC se estimó en 40 casos para las resecciones en cuña y en 65 casos para las resecciones anatómicas. CONCLUSIÓN: La LC de la resección hepática laparoscópica de los segmentos PS es un proceso paso a paso durante el cual la selección del paciente es clave.

Conventional surgical navigation systems rely on preoperative imaging to provide guidance. In laparoscopic liver surgery, insufflation of the abdomen (pneumoperitoneum) can cause deformations on the liver, introducing inaccuracies in the correspondence between the preoperative images and the intraoperative reality. This study evaluates the improvements provided by intraoperative imaging for laparoscopic liver surgical navigation, when displayed as augmented reality (AR). Significant differences were found in terms of accuracy of the AR, in favor of intraoperative imaging. In addition, results showed an effect of user-induced error: image-to-patient registration based on annotations performed by clinicians caused 33% more inaccuracy as compared to image-to-patient registration algorithms that do not depend on user annotations. Hence, to achieve accurate surgical navigation for laparoscopic liver surgery, intraoperative imaging is recommendable to compensate for deformation. Moreover, user annotation errors may lead to inaccuracies in registration processes. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Introduction: In liver surgery, medical images from pre-operative computed tomography and magnetic resonance imaging are the basis for the decision-making process. These images are used in surgery planning and guidance, especially for parenchyma-sparing hepatectomies. Though medical images are commonly visualized in two dimensions (2D), surgeons need to mentally reconstruct this information in three dimensions (3D) for a spatial understanding of the anatomy. The aim of this work is to investigate whether the use of a 3D model visualized in mixed reality with Microsoft HoloLens increases the spatial understanding of the liver, compared to the conventional way of using 2D images. Material and methods: In this study, clinicians had to identify liver segments associated to lesions. Results: Twenty-eight clinicians with varying medical experience were recruited for the study. From a total of 150 lesions, 89 were correctly assigned without significant difference between the modalities. The median time for correct identification was 23.5 [4–138] s using the magnetic resonance imaging images and 6.00 [1–35] s using HoloLens (p

Importance: Textbook outcome (TO) is a composite measure that captures the most desirable surgical outcomes as a single indicator, yet to date TO has not been defined and assessed in the field of laparoscopic liver resection (LLR) and open liver resection (OLR). Objective: To obtain international agreement on the definition of TO in liver surgery (TOLS) and to assess the incidence of TO in LLR and OLR in a large international multicenter database using a propensity-score matched analysis. Design, Setting, and Participants: Patients undergoing LLR or OLR for all liver diseases between January 2011 and October 2019 were analyzed using a large international multicenter liver surgical database. An international survey was conducted among all members of the European-African Hepato-Pancreato-Biliary Association (E-AHPBA) and International Hepato-Pancreato-Biliary Association (IHPBA) to reach agreement on the definition of TOLS. The rate of TOLS was assessed for LLR and OLR before and after propensity-score matching. Factors associated with achieving TOLS were investigated. Main Outcomes and Measures: Textbook outcome, with TOLS defined as the absence of intraoperative incidents of grade 2 or higher, postoperative bile leak grade B or C, severe postoperative complications, readmission within 30 days after discharge, in-hospital mortality, and the presence of R0 resection margin. Results: A total of 8188 patients (4559 LLR; median age, 65 years [interquartile range, 55-73 years]; 2529 were male [55.8%] and 3629 OLR; median age, 64 years [interquartile range, 56-71 years]; 2204 were male [60.7%]) were included in the analysis of whom 69.1% achieved TOLS; 74.8% for LLR and 61.9% for OLR (P 10 cm = OR, 0.550 [95% CI, 0.366-0.826]; P =.004) were associated with a worse TOLS rate. Conclusions and Relevance: In this multicenter study, TOLS was found to be a useful tool for assessing patient-level hospital performance and may have utility in optimizing patient outcomes after LLR and OLR..

Background: Liver resection or ablation remains the only curative treatment for patients with colorectal metastases. Simultaneous resection of tumors in the liver with invasion to the diaphragm is challenging and controversial. Therefore, we wanted to assess the safety of simultaneous laparoscopic liver and diaphragm resection (SLLDR) in a large single center. Methods: Patients who underwent primary laparoscopic liver resection (LLR) for colorectal liver metastases at Oslo University Hospital between 2008 and 2019 were included in this study. Patients who underwent SLLDR (group 1) were compared to patients who underwent LLR only (group 2). Perioperative and oncologic outcomes were analyzed. Results: A total of 467 patients were identified, of whom 12 patients needed a simultaneous diaphragm resection (group 1) while 455 underwent laparoscopic liver surgery alone (group 2). The conversion rate was 16.7% in group 1 and 2.4% in group 2 (P=0.040). In 10 of 12 (83.3%) cases the diaphragm resection was performed en bloc with the liver tumor. There was no significant difference in operative time, blood loss, resection margins, hospital stay or postoperative complications. One patient died within 30 postoperative days (0.2%) in group 2 and none in group 1. Overall survival was not statistically different between the groups. Conclusions: In selected patients, SLLDR can be performed safely with good surgical and oncological outcomes. Keywords: Laparoscopic hepatectomy; diaphragm resection; combined procedures; colorectal metastases

Background Laparoscopic liver resection in the posterosuperior segments is technically challenging. This study aimed to compare the perioperative outcomes for laparoscopic and open resection of colorectal liver metastases located in the posterosuperior segments. Methods This was a subgroup analysis of the OSLO-COMET randomized controlled trial, where 280 patients were randomly assigned to open or laparoscopic parenchyma-sparing liver resections of colorectal metastases. Patients with tumors in the posterosuperior segments were identified, and perioperative outcomes and health related quality of life (HRQoL) were compared. Results We identified a total of 136 patients, 62 in the laparoscopic and 74 in the open group. The postoperative complication rate was 26% in the laparoscopic and 31% in the open group. The blood loss was less in the open group (500 vs. 250 ml, P = 0.006), but the perioperative transfusion rate was similar. The operative time was similar, while postoperative hospital stay was shorter in the laparoscopic group (2 vs. 4 days, P < 0.001). HRQoL was significantly better after laparoscopy at 1 month. Conclusion In patients undergoing laparoscopic or open liver resection of colorectal liver metastases in the posterosuperior segments, laparoscopic surgery was associated with shorter hospital stay and comparable perioperative outcomes.

Extended resection is required for pancreatic adenocarcinoma infiltrating adjacent organs and structures. The role of laparoscopy in this setting is unclear. In this study, the outcomes of extended laparoscopic distal pancreatectomy (ELDP) for pancreatic body/tail adenocarcinoma were examined. Perioperative and oncologic data were analyzed in patients undergoing laparoscopic distal pancreatectomy (LDP) for adenocarcinoma at Oslo University Hospital. ELDP was defined as suggested by the International Study Group for Pancreatic Surgery. The outcomes of ELDP were compared to those following standard LDP (SLDP). From August 2001 to June 2016, 460 consecutive patients underwent LDP for pancreatic neoplasms including 116 (25%) adenocarcinoma. SLDP and ELDP were applied in 78 and 31 patients, respectively. The adrenal gland (33%) and colon (21%) were the most frequently resected organs during ELDP. The latter was associated with larger tumor size (5.5 vs 4 cm, p = 0.03), longer operative time (236 vs 158 min, p = 0.001) and higher conversion rate (16 vs 3%, p = 0.019) compared with SLDP. Morbidity and 90-day mortality were similar. Median follow-up was 18 months. In patients with ductal adenocarcinoma, ELDP (n = 22) was associated with significantly shorter recurrence-free and overall survival than SLDP (n = 59) (6.2 vs 9.6 months, p = 0.047 and 12.9 vs 27 months, p

The role of surgery in the management of metastatic gastric cancer (MGC) remains unclear. The aim of this study was to investigate the surgical and oncologic outcomes of gastrectomy in patients with MGC. The study included prospectively collected data of patients with MGC operated at four medical centers in Yerevan, Armenia, between 2000 and 2014. Armenian National Center of Oncology Registry and hospital records were used to obtain survival data. Factors associated with performing gastrectomy in patients with MGC were analyzed by using the logistic regression model. The Kaplan-Meier method was applied for survival analysis, and the Cox regression model with backward selection was used for multivariate analysis. A total number of 733 patients were operated for gastric cancer including 112 (15.3%) with MGC. Of those, 70 underwent gastrectomy, while 42 had exploratory laparotomy or bypass. Morbidity and mortality were similar after gastrectomy and exploratory laparotomy/bypass (18.6 vs 21.4%, p = 0.71 and 2.9 vs 7.1% p = 0.36, respectively). Female gender, involvement of N1 and/or N2 lymph node stations, and differentiated adenocarcinoma were associated with opting for gastrectomy. Gastrectomy with synchronous resection of distant metastases resulted in postoperative outcomes similar to those following gastrectomy without synchronous organ resection. Median follow-up was 6 months. Eighteen (16.1%) patients received chemotherapy. Median survival following gastrectomy and exploratory laparotomy/bypass were 7 and 4 months (p = 0.015), respectively. The use of chemotherapy following gastrectomy significantly improved survival compared with gastrectomy only (14 vs 6 months, p = 0.01). In the multivariable analysis, chemotherapy and nodal stage correlated with survival after gastrectomy. Gastrectomy for MGC is associated with satisfactory surgical outcomes and can be combined with synchronous resection of distant metastases in selected patients. Gastrectomy results in longer survival compared with exploratory laparotomy/bypass, especially when followed by chemotherapy.

Stage IV metastatic melanoma carries a poor prognosis. In the case of melanoma liver metastasis (MLM), surgical resection may improve survival and represents a therapeutic option, with varying levels of success. Laparoscopic liver resection (LLR) for metastatic melanoma is poorly studied. The aim of this study was to analyze the outcomes of LLR in patients with MLM. Between April 2000 and August 2013, 11 (1 cutaneous, 9 ocular and 1 unknown primary) patients underwent LLR for MLM at Oslo University Hospital—Rikshospitalet and 13 procedures in total were carried out. Perioperative and oncologic outcomes were analyzed. Postoperative morbidity was classified using the Accordion classification. Kaplan–Meier method was used for survival analysis. A total of 23 liver specimens were resected. The median operative time was 137 (65–470) min, while the median blood loss was less than 50 (

BackgroundLaparoscopic liver resection (LLR) of colorectal liver metastases (CLM) is increasingly performed in specialized centers. While there is a trend towards a parenchyma-sparing strategy in multimodal treatment for CLM, its role is yet unclear. In this study we present short- and long-term outcomes of laparoscopic parenchyma-sparing liver resection (LPSLR) at a single center.Patients and methodsLLR were performed in 951 procedures between August 1998 and March 2017 at Oslo University Hospital, Oslo, Norway. Patients who primarily underwent LPSLR for CLM were included in the study. LPSLR was defined as non-anatomic hence the patients who underwent hemihepatectomy and sectionectomy were excluded. Perioperative and oncologic outcomes were analyzed. The Accordion classification was used to grade postoperative complications. The median follow-up was 40 months.Results296 patients underwent primary LPSLR for CLM. A single specimen was resected in 204 cases, multiple resections were performed in 92 cases. 5 laparoscopic operations were converted to open. The median operative time was 134 minutes, blood loss was 200 ml and hospital stay was 3 days. There was no 90-day mortality in this study. The postoperative complication rate was 14.5%. 189 patients developed disease recurrence. Recurrence in the liver occurred in 146 patients (49%), of whom 85 patients underwent repeated surgical treatment (liver resection [n = 69], ablation [n = 14] and liver transplantation [n = 2]). Five-year overall survival was 48%, median overall survival was 56 months.ConclusionsLPSLR of CLM can be performed safely with the good surgical and oncological results. The technique facilitates repeated surgical treatment, which may improve survival for patients with CLM.

LBA3516 Background: Despite the recent worldwide dissemination of laparoscopic liver surgery, the long-term oncologic outcomes of laparoscopic and open liver surgery have never been compared in a randomized controlled trial. Methods: OSLO-COMET was a randomized controlled trial recruiting patients from Oslo University Hospital, Oslo, Norway. The primary outcome of the trial was postoperative morbidity within 30 days. Patients with radically resectable liver metastases from colorectal cancer were randomly assigned to undergo laparoscopic or open parenchyma-sparing liver resection. Overall survival was a predefined secondary endpoint for the trial. Survival data for the treatment arms will be compared using a log-rank test and Kaplan-Meier plots. Results: From February 2012 to January 2016 a total of 294 patients were screened and 280 (95%) patients were randomized to laparoscopic (n = 133) or open (n = 147) surgery. The primary endpoint demonstrated a significant reduction in morbidity from 31% in the open group to 19% in the laparoscopic group. Other secondary outcomes demonstrated no difference between the groups, including the rate of R0 resection and the width of resection margins, while laparoscopic surgery was found to be cost-effective. Patients received perioperative chemotherapy following Norwegian guidelines. The final patient was operated on Feb 28, 2016, and a survival analysis was performed on March 14, 2019, with a minimum of 36 months follow-up. By ITT analysis (n = 280), median overall survival (OS) was 80 months (95% CI 52-108) in the laparoscopic surgery group and 81 months (95% CI 42-120) in the open surgery group, p=0.91. By modified ITT, (only patients that had R0/R1 resection), median recurrence free survival (RFS) was 19 months (10-27) in the laparoscopic group and 16 months (11-21) in the open group, p = 0.96. Conclusions: Laparoscopic surgery in patients with colorectal liver metastases was associated with rates of OS and RFS similar to open surgery. Clinical trial information: NCT01516710.

Purpose: This study aims to evaluate the accuracy of point-based registration (PBR) when used for augmented reality (AR) in laparoscopic liver resection surgery. Material and methods: The study was conducted in three different scenarios in which the accuracy of sampling targets for PBR decreases: using an assessment phantom with machined divot holes, a patient-specific liver phantom with markers visible in computed tomography (CT) scans and in vivo, relying on the surgeon’s anatomical understanding to perform annotations. Target registration error (TRE) and fiducial registration error (FRE) were computed using five randomly selected positions for image-to-patient registration. Results: AR with intra-operative CT scanning showed a mean TRE of 6.9 mm for the machined phantom, 7.9 mm for the patient-specific phantom and 13.4 mm in the in vivo study. Conclusions: AR showed an increase in both TRE and FRE throughout the experimental studies, proving that AR is not robust to the sampling accuracy of the targets used to compute image-to-patient registration. Moreover, an influence of the size of the volume to be register was observed. Hence, it is advisable to reduce both errors due to annotations and the size of registration volumes, which can cause large errors in AR systems.

Meticulous preoperative planning is an important part of any surgery to achieve high levels of precision and avoid complications. Conventional medical 2D images and their corresponding three-dimensional (3D) reconstructions are the main components of an efficient planning system. However, these systems still use flat screens for visualisation of 3D information, thus losing depth information which is crucial for 3D spatial understanding. Currently, cutting-edge mixed reality systems have shown to be a worthy alternative to provide 3D information to clinicians. In this work, we describe development details of the different steps in the workflow for the clinical use of mixed reality, including results from a qualitative user evaluation and clinical use-cases in laparoscopic liver surgery and heart surgery. Our findings indicate a very high general acceptance of mixed reality devices with our applications and they were consistently rated high for device, visualisation and interaction areas in our questionnaire. Furthermore, our clinical use-cases demonstrate that the surgeons perceived the HoloLens to be useful, recommendable to other surgeons and also provided a definitive answer at a multi-disciplinary team meeting.