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Lipomas are benign, slow growing soft tissue neoplasm that present as soft, painless nodules that are most commonly seen on the trunk but can be located anywhere on the body. They are however seldomly encountered within in the parotid region. It's occurrence in this region also makes its surgical resection challenging due to its close relation to the facial nerve and its branches. We report a case of lipoma of the parotid region in a 30-yearold man who had a 5.0 × 3.0 cm soft mass in the right parotid gland which was managed surgically., Competing Interests: Conflict of interestThere are no conflict of interest., (© Association of Otolaryngologists of India 2023. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

Background: Socioeconomic status (SES) is multifactorial, and its effect on post-bariatric weight recurrence is unclear. Distressed Community Index (DCI) is a composite SES score measuring community economic well-being. This study aims to evaluate the effect of DCI on long-term post-bariatric weight outcomes., Methods: Retrospective analysis of patients undergoing primary laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy between 2015 and 2020 was performed. All weights in the electronic medical record (EMR), including non-bariatric visits, were captured. Patients were stratified into low tier (LT) and high tier (HT) DCI groups., Results: Of 583 patients, 431 (73.9%) were HT and 152 (26.1%) were LT. Average bariatric follow up was 1.78 ± 1.6 years and average postoperative weight in the EMR was 3.96 ± 2.26 years. Rates of bariatric follow up within the last year were similar (13.8% LT vs 16.2% HT, p = 0.47). LT had higher percent total body weight loss (%TWL; 26% LT vs 23% HT, p < 0.01) and percent excess weight loss (%EWL; 62% vs 57%, p = 0.04) at 1 year on univariate analysis. On multivariate linear regression adjusting for baseline characteristics and surgery type, there were no differences in %EWL between groups at 1 year (p = 0.22), ≥ 3 years (p = 0.53) or ≥ 5 years (p = 0.34) postop. While on univariate analysis LT only trended towards greater percentage of patients with > 15% increase from their 1-year weight (33.3% LT vs 21.0% HT, p = 0.06), on multivariate analysis this difference was significant (OR 2.0, LT 95%CI 1.41-2.84). There were no differences in the percentage of patients with > 15% decrease in %EWL from 1 to 3 + years postop between groups (OR 0.98, LT 95% CI 0.72-1.35)., Conclusions: While low tier patients had similar weight loss at 1 year, they were twice as likely to have weight recurrence at ≥ 3 years. Further studies are needed to identify factors contributing to greater weight recurrence among this population., (© 2023. The Author(s).)

More than half of the CO 2 emissions during the manufacturing of ordinary Portland cement (OPC) occur due to the calcination of calcium carbonate in addition to burning of fossil fuel to power the process. Consequently, there is a concerted effort to decrease the carbon footprint associated with this process, by minimizing the use of OPC. In line with this trend, an attempt was made in the reported study to synthesize a novel alkali-activated binder using CaCO 3 -rich waste limestone powder (WLSP) as a precursor. Utilizing the Taguchi method, four important parameters were varied at three levels to optimize the alkali-activated mixture. Analysis of variance (ANOVA) of the obtained results was performed to assess the impact of each of the factors on the properties of the developed binder. To enhance the strength further, OPC was added as a partial replacement of WLSP. The binder was characterized using scanning electron microscopy. The results have indicated that alkaline activator to binder ratio, Na 2 SiO 3 to NaOH ratio, and sand to binder ratio of 0.575, 1.57, and 2.5, respectively, were the optimum to obtain satisfactory strength and workability with a 13.7-M NaOH activator solution. The incorporation of a small quantity of OPC in the mixture remarkably improved the density and strength of the alkali-activated-WLSP binder. Pirssonite (CaCO 3 .Na 2 CO 3 .2H 2 O) and C/N-A-S-H were the dominant mineral phases formed in the developed binder, particularly in the ones alkali-activated WLSP/OPC. In addition, the eco-efficiency assessment revealed that the WLSP is a promising low-carbon binder that can be used in developing more sustainable alkali-activated binder. The results have shown that the WLSP can be potentially utilized in developing binder that can be potentially used in the structural applications., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Alkali-activated concrete (AAC) or binders (AABs) have emerged as a substitute to conventional ordinary Portland cement (OPC)-based concrete owing to their techno-ecological merits. Saudi Arabia has vast resources of natural pozzolan whose impact on some fresh and hardened properties was encouraging; however, the long-term shrinkage behavior of AABs and life cycle assessment (LCA) of the developed product is yet to be explored. Therefore, this study evaluates shrinkage characteristics and LCA of Saudi natural pozzolan (NP)-based AAC. The synergistic impact of admixing nano-silica (NS) up to 7.5% dosage was also observed on the properties of engineered AABs in comparison with OPC-based concrete. The shrinkage properties were correlated with the microstructure and pore structure. The study revealed that the shrinkage properties of both NP-based AABs and OPC-based concrete are comparable. However, adding NS increased the drying shrinkage strain because of the finer pore structure than AABs without NS, which was confirmed through nuclear magnetic resonance (NMR). The maximum average drying shrinkage strain of 510 με was recorded in the OPC concrete, whereas in the engineered AAC with 0, 1, 2.5, 5, and 7.5% NS, it was 486, 537, 568, 601, and 651 με, respectively. It is postulated that the NP can be beneficially valorized in the production of green AABs without compromising the shrinkage characteristics, while the NS is favorable for enhancing the strength and refinement of the pore matrix. Besides, the LCA indicated the feasibility of recycling the high volume of natural waste by AAB technology, which significantly lowers the carbon footprints and minimizes the environmental implications in infrastructural applications., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Gastrointestinal symptoms such as diarrhea, bloating, abdominal pain, and nausea are common after bariatric surgery (BS) and can lead to significant morbidity. While many diagnoses can explain these symptoms, post-bariatric exocrine pancreatic insufficiency (EPI) is becoming increasingly recognized as contributor to gastrointestinal symptoms. The frequency and outcomes of EPI after BS are not well understood. We investigated the prevalence and outcomes of EPI over 18 years at a tertiary bariatric referral center., Methods: A retrospective review of patients who underwent primary or revisional BS from 2002 to 2020 was performed. Patients were included if they were suspected of having EPI or underwent fecal elastase testing (FE-1). EPI diagnosis was defined as positive FE-1 testing or improvement with empiric pancreatic enzyme replacement therapy (PERT)., Results: EPI was suspected in 261 patients, and 190 were tested via FE-1 (89.5%) or empirically treated (10.5%). EPI was diagnosed in 79 (41.6%) patients and was associated with older age and lower BMI. Therapeutic PERT was given to 65 patients diagnosed with EPI, and 56 (86.2%) patients reported improved symptoms. Patients who underwent RYGB and BPD-DS were more likely to have EPI than those after SG (47.9% and 70.0% vs 17.4%, p < 0.01). EPI diagnosis was associated with a history chronic pancreatitis. While diarrhea and abdominal pain were the most common symptoms prompting FE-1 testing, no symptoms were significantly associated with EPI. EPI was also associated with abnormal fecal fat results and treatment with bile acid sequestrants, but not small intestinal bacterial overgrowth., Conclusion: This study highlights that exocrine pancreatic insufficiency can account to for previously unexplained GI complaints after bariatric surgery. Therefore, bariatric surgery programs should consider this diagnosis in symptomatic patients, especially following RYGB and BPD-DS. Further work to define patient factors that should prompt evaluation, optimal treatment, and prevention is necessary., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The present study is to investigate the Gudermannian neural networks (GNNs) using the optimization procedures of genetic algorithm and active-set approach (GA-ASA) to solve the three-species food chain nonlinear model. The three-species food chain nonlinear model is dependent upon the prey populations, top-predator, and specialist predator. The design of an error-based fitness function is presented using the sense of the three-species food chain nonlinear model and its initial conditions. The numerical results of the model have been obtained by exploiting the GNN-GA-ASA. The obtained results through the GNN-GA-ASA have been compared with the Runge-Kutta method to substantiate the correctness of the designed approach. The reliability, efficacy and authenticity of the proposed GNN-GA-ASA are examined through different statistical measures based on single and multiple neurons for solving the three-species food chain nonlinear model., Competing Interests: Conflict of interestThere is no conflict of interest. All authors contributed equally., (© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2021.)

Background: Despite similar rates of obesity among American men and women, population-based studies suggest that bariatric surgery patients are disproportionately female. We sought to assess this observation quantitatively., Methods: Data were prospectively collected from 1,368 consecutive patients evaluated for bariatric surgery over a 4-year period. The prevalence of diabetes mellitus (DM), hypertension (HTN), dyslipidemia (DYS), obstructive sleep apnea (OSA), gastroesophageal reflux disease, depression, back pain (BKP), and musculoskeletal peripheral disease was assessed. A severity score from 1 to 5 had been assigned to each comorbidity based on the Assessment of Obesity Related Comorbidities Scale (AORC). Metabolic syndrome (MetS) was defined as the concurrent presence of DM, HTN, and DYS., Results: The majority of patients were female (n = 1,115, 81.5%). Male patients were older (44.5 ± 9.5 vs. 42.6 ± 9.6 years, p = 0.0044) and had higher body mass index (48.7 ± 7.8 vs. 46.6 ± 7.4 kg/m(2), p < 0.0001). On average, men presented with 4.54 serious comorbidities and 3.7 complicated comorbidities (AORC score ≥3), whereas women presented with 4.15 serious comorbidities and 3.08 complicated comorbidities. More men presented with DM (36.4 vs. 28.9%, p = 0.0154), HTN (68.8 vs. 55.3%, p = 0.0001), OSA (71.9 vs. 45.7%, p < 0.0001), and MetS (20.9 vs. 15.2%, p = 0.0301). Men also presented with more complicated DM (33.2 vs. 23.9%, p = 0.0031), DYS (36.8 vs. 23.5%, p < 0.0001), HTN (58.9 vs. 44.6%, p < 0.0001), BKP (25.3 vs. 19.3%, p = 0.0378), OSA (56.9 vs. 30.1%, p < 0.0001), and MetS (17.8 vs. 10.0%, p = 0.001)., Conclusions: Although men typically comprise less than 20% of bariatric surgery patients, they potentially have more to gain from these operations. Men present later in life, with more advanced obesity, and with more complicated comorbidities. Such findings mandate more research and resources to investigate this barrier to treatment and to provide the morbidly obese male with the surgical care he clearly needs.

Background: The concept that advanced surgical training can reduce or eliminate the learning curve for complex procedures makes logical sense but is difficult to verify and has not been tested for laparoscopic Roux-en-Y gastric bypass (LRYGB). We sought to determine if minimally invasive/bariatric surgery fellowship graduates (FGs) would demonstrate complication-related outcomes (CRO) equivalent to the outcomes achieved during their training experience under the supervision of experienced bariatric surgeons., Methods: We compared CRO for the first 100 consecutive LRYGBs performed in practice by five consecutive minimally invasive/bariatric fellows at new institutions (total 500 cases) to CRO for the 611 consecutive LRYGBs performed during their fellowship training experience under the supervision of three experienced bariatric surgeons at the host training institution., Results: The two patient groups did not differ demographically. The 18 types of major and minor complications identified after LRYGB did not differ among the five fellowship graduates. The mentors' CRO were compatible with published benchmark data. As compared with the training institution data, the overall incidence of complications for the combined experience of fellowship graduates did not differ statistically from that of the mentors. The fellowship graduates' early experience included zero non-gastrojejunostomy leaks (0% versus 1.5%) and a low rate of anastomotic stricture (0.8% versus 3.0%), incisional hernia (1% versus 4.4%), bowel obstruction (0% versus 3%), wound infection (0.3% versus 3.1%), and gastrointestinal hemorrhage (0.2% versus 1.6%). The rate of gastrojejunostomy leak (1.8% versus 2.6%) and, most importantly, mortality (0.8% versus 0.7%) did not differ between the two groups., Conclusions: Fellowship graduates achieved high-quality surgical outcomes from the very beginning of their post-fellowship practices, which are comparable to those of their experienced mentors. These data validate the concept that advanced surgical training can eliminate the learning curve often associated with complex minimally invasive procedures, specifically LRYGB.

Background: Routine upper gastrointestinal (UGI) studies following laparoscopic Roux-en-Y gastric bypass (LRYGBP) have the potential advantage of early identification of anastomotic complications. The aim of our study was to evaluate the efficacy of routine postoperative UGI and its relationship to clinical outcomes., Methods: Over a three-year period, 516 patients underwent LRYGBP followed by routine postoperative UGI studies. Data were collected on the results of the UGI, clinical parameters, and patient outcomes. Study groups were composed of patients with a normal UGI (Group I, n = 455), abnormal UGI not requiring further intervention (Group II, n = 36), and abnormal UGI requiring further intervention (Group III, n =25). Statistical significance was set at alpha= 0.05 level for all analyses., Results: The three study groups were not statistically different in mean age (42 years) or body mass index (BMI) (45) and were predominantly female (90%). Most patients had an uneventful postoperative course. Anastomotic complications (gastrojejunostomy and jejunojejunostomy) were uncommon (1.3%). The sensitivity of the UGI for anastomotic leak in this study was low (33%). However, all patients with alimentary limb obstruction (n = 3) had UGI evidence of this complication. Of the 516 UGI reports, there were only 25 (4.8%, Group III) that were abnormal and required some form of intervention ranging from serial imaging (84%) to reoperation (16%). Of the various clinical parameters examined, the patients in Group III demonstrated a significantly higher prevalence of fever (p < 0.001), tachycardia (p < 0.01), vomiting (p < 0.001), and postoperative day 1 leukocytosis (p < 0.005)., Conclusions: Our data suggest that routine UGI after LRYGBP has limited utility as it may result in unnecessary intervention based on false-positive results or a delay in treatment based on false-negative results. We advocate selective UGI imaging following LRYGBP based on the patient's clinical factors, particularly fever and tachycardia.

Background: Marginal ulceration after Roux-en-Y gastric bypass (RYGB) is diagnosed in 1% to 16% of patients. The factors predisposing patients to marginal ulceration are still unclear., Methods: A total of 260 patients who underwent laparoscopic RYGB were retrospectively reviewed. Data regarding demographics, comorbidities, body mass index (BMI), Helicobacter pylori infection, gastrojejunal (GJ) anastomotic leaks, postoperative bleeding, operative time, type of suture material, and marginal ulcer formation were collected. Fisher's exact test was used for statistical analysis of discrete variables, and Student's t-test was used for continuous variables. Statistical significance was set at an alpha of 0.05., Results: The overall marginal ulceration rate was 7%. Demographic data (age, gender distribution, BMI) did not differ significantly between patients who experienced marginal ulceration and those who did not (p > 0.05). Similarly, technical factors (choice of permanent or absorbable suture for the GJ anastomosis, attending as primary surgeon, robotic GJ, operative time, postoperative hematocrit drop) were not statistically different between the two groups (p > 0.05). Finally, the prevalence of comorbidities (diabetes, hypertension, obstructive sleep apnea, musculoskeletal complaints, dyslipidemia, gastroesophageal reflux disease [GERD] and peptic ulcer disease [PUD]) did not differ significantly between the two groups (p > 0.05). However, preoperative H. pylori infection, although adequately treated, was twice as common among the patients who had marginal ulceration (32%) as among those who did not (12%) (p = 0.02). All the patients who experienced marginal ulcers had complete resolution of symptoms with proton pump inhibitors and sucralfate. No reoperations were required for marginal ulceration., Conclusion: Helicobacter pylori may potentiate marginal ulcer formation. The authors hypothesize that H. pylori damages the mucosal barrier in a way that persists postoperatively, which may precipitate marginal ulceration even when the organism has been medically eradicated.

Background: After an initial institutional experience with 50 robot-assisted laparoscopic Roux-en-Y gastric bypass procedures, a curriculum was developed for fellowship training in robotic surgery., Methods: Thirty consecutive robotic gastric bypasses were performed using the Zeus robotic surgical system to fashion a two-layer gastrojejunostomy. For teaching purposes, performance of the anastomosis was divided into three discrete tasks. Robotic suturing tasks were assigned to the trainee in cumulative order in ten-case increments. Our patient population averaged 44 years of age and 47 kg/m(2) in BMI. Patients were predominantly female (87%)., Results: The robotic training experience of the fellow defines the increases in surgical responsibility over the series of cases. Statistical analysis revealed no significant differences in task times or total robotic operative time as participation of the trainee in performing the gastrojejunostomy increased. No adverse robotic events or surgical complications occurred throughout this series. The learning curve of the fellow compared favorably with the initial experience of the institution., Conclusion: Robotic surgery training may be safely implemented in a minimally invasive surgery training program. A gradual introduction of robotic technique appears to maximize the learning experience and minimize the potential for adverse outcomes.

Background: Robotic surgery promises to extend the capabilities of the minimally invasive surgeon. The aim of this study was to examine the feasibility of robotic surgery in the setting of laparoscopic gastric bypass., Methods: The Zeus robotic surgical system was used in 50 laparoscopic gastric bypass procedures. The learning curve was staged to add complexity to the robotic tasks as experience grew. Robotic setup time, robotic operative time, total operative time, and operative outcomes were tracked prospectively., Results: We observed a significant decrease in the robotic setup time. Our robotic learning curve demonstrated decreased operative time, even as more complex tasks were accomplished. Total operative time also decreased significantly over the series. There were no complications in our series that could be attributed to the robotic technique., Conclusions: Robot-assisted laparoscopic Roux-en-Y gastric bypass is safe. The steadiness and extra degrees of freedom of surgical robotic systems may improve the accuracy of laparoscopic tasks. The learning curve for robot-assisted laparoscopic Roux-en-Y gastric bypass is significant but manageable.

Background: Virtual reality simulation is effective in training the novice to perform basic laparoscopic skills., Methods: Using the Minimally Invasive Surgery Training--Virtual Reality (MIST-VR) trainer, 27 honors high school students were tested at the easy level, prospectively randomized to eight training sessions at the easy (group A, n = 14) or medium (group B, n = 13) level, then retested at the easy level., Results: Both groups were statistically similar at baseline. All scores improved significantly (50.1% to 81.3%) over the period of training (p < 0.05). Although the group A scores were significantly better than the group B scores throughout training (p < 0.05), on final testing at the easy level, group B surpassed group A for all the tasks except TransferPlace (p = 0.054)., Conclusions: Virtual simulation is an effective laparoscopic training method for the novice, providing significant improvement in skill levels over a relatively short period. More challenging training seems to predict greater improvement over time and better final skill levels.