Summary Background and Aims Weight recidivism following sleeve gastrectomy (SG) is common. Adjuvant treatments include new glucagon‐like peptide 1 and glucose‐dependent insulinotropic peptide receptor agonists (GLP1/GIP‐RA) or revisional endoscopic sleeve gastroplasty (R‐ESG). We here compare the outcomes of these treatments. Methods A retrospective study of patients ≥18 years with prior SG treated with semaglutide, tirzepatide or R‐ESG for weight recidivism between January 2019 and 2023 at large academic centre. Primary outcomes were total body weight loss (TBWL) and adverse events (AEs). Secondary outcomes were changes in metabolic parameters. Tertiary outcome was to compare GLP1/GIP‐RA outcomes in SG patients to matched patients with intact stomach. Results Our study included 68 (prior SG + GLP1/GIP‐RA) and 22 (prior SG + R‐ESG). R‐ESG offered higher TBWL% than GLP1/GIP‐RA at 3 (11.2% vs. 4.3%, p < .001), 6 (13.5% vs. 6.8%, p < .001) and 12 months (13.4% vs. 9.2%, p = .07) with no significant difference in AEs or change in metabolic parameters. On subgroup analysis, tirzepatide achieved similar 12‐months TBWL% as R‐ESG (13.2% vs. 13.4%, p = .9) and significantly more than semaglutide (13.2% vs. 8.1%, p = .04). Compared to patients with intact stomach ( n = 87), GLP1/GIP‐RA achieved significantly lower TBWL% in patients with prior SG at 3 (4.3% vs. 5.7%, p = .02), 6 (6.8% vs. 9.2%, p = .02) and 12 months (9.2% vs. 12.7%, p = .03). Medication refills were difficult in 41.3% of patients. Conclusions In a single‐centre real‐world experience study, R‐ESG and tirzepatide appear to offer more weight loss than semaglutide in SG patients with weight recidivism although GLP1/GIP‐RA were underdosed. GLP1/GIP‐RA achieved higher weight loss in patients with intact stomach than those with prior SG.

Objective: To assess the external validity of randomized controlled trials (RCTs) of bariatric surgical treatment on diabetes control. Background: Multisite RCTs provide the strongest evidence supporting clinical treatments and have the greatest internal validity. However, characteristics of trial participants may not be representative of patients receiving treatment in the real world. There is a need to assess how the results of RCTs generalize to all contemporary patient populations undergoing treatments. Methods: All patients undergoing sleeve gastrectomy at University of California Los Angeles (UCLA) between January 8, 2018 and May 19, 2023 had their baseline characteristics, weight change, and diabetes control compared with those enrolled in the surgical treatment and medications potentially eradicate diabetes efficiently (STAMPEDE) and diabetes surgery study (DSS) RCTs of bariatric surgery’s effect on diabetes control. Weight loss and diabetes control were compared between UCLA patients who did and did not fit the entry criteria for these RCTs. Results: Only 65 (17%) of 387 patients with diabetes fulfilled the eligibility criteria for STAMPEDE, and 29 (7.5%) fulfilled the criteria for DSS due to being older, having higher body mass index, and lower HbA1c. UCLA patients experienced slightly less weight loss than patients in the RCTs but had similar diabetes control. The 313 (81%) patients not eligible for study entry into either RCT had similar long-term diabetes control as those who were eligible for the RCTs. Conclusions: Even though only a very small proportion of patients undergoing bariatric surgery met the eligibility criteria for the 2 major RCTs, most patients in this contemporary cohort had similar outcomes. Diabetes outcomes from STAMPEDE and DSS generalize to most patients undergoing bariatric surgery for diabetes control.

Grit is a person’s ability to establish long-term goals and work to achieve those goals irrespective of any barriers. We examined the relationship between the personality trait grit, obesity, and metabolic and bariatric surgery (MBS)–induced weight loss. In an ongoing prospective cohort, 104 adult patients who underwent laparoscopic sleeve gastrectomy (LSG) had preoperative grit questionnaires administered. The association between grit domains and 1-year weight loss was evaluated by ANCOVA. Among the 104 patients who completed a pre-operative grit survey, 74 completed the survey again 1 year after surgery (72.1

Introduction: Metabolic dysfunction-associated steatotic liver disease (MASLD) affects nearly 25% of the population and is the leading cause for liver-related mortality. Bariatric surgery is a well-known treatment for MASLD and obesity. Understanding the fundamental mechanisms by which bariatric surgery can alter MASLD can lead to new avenues of therapy and research. Previous studies have identified the microbiome's role in bariatric surgery and in inflammatory immune cell populations. The host innate immune system modulates hepatic inflammation and fibrosis, and thus the progression of MASLD. The precise role of immune cell types in the pathogenesis of MASLD remains an active area of investigation. The aim of this study was to understand the interplay between microbiota composition post-bariatric surgery and the immune system in MASLD. Methods: Eighteen morbidly obese females undergoing sleeve gastrectomy were followed pre-and post-surgery. Stool from four patients, showing resolved MASLD post-surgery with sustained weight loss, was transplanted into antibiotic treated mice. Mice received pre-or post-surgery stool and were fed a standard or high-fat diet. Bodyweight, food intake, and physiological parameters were tracked weekly. Metabolic parameters were measured post-study termination. Results: The human study revealed that bariatric surgery led to significant weight loss (p > 0.05), decreased inflammatory markers, and improved glucose levels six months post-surgery. Patients with weight loss of 20% or more showed distinct changes in blood metabolites and gut microbiome composition, notably an increase in Bacteroides. The mouse model confirmed surgery-induced microbiome changes to be a major factor in the reduction of markers and attenuation of MASLD progression. Mice receiving post-surgery fecal transplants had significantly less weight gain and liver steatosis compared to pre-surgery recipients. There was also a significant decrease in inflammatory cytokines interferon gamma, interleukin 2, interleukin 15, and mig. This was accompanied by alterations in liver immunophenotype, including an increase in natural killer T cells and reduction of Kupfer cells in the post-surgery transplant group. Discussion: Our findings suggest surgery induced microbial changes significantly reduce inflammatory markers and fatty liver progression. The results indicate a potential causal link between the microbiome and the host immune system, possibly mediated through modulation of liver NKT and Kupffer cells.

Almost half of the adult population in the United States have high blood pressure, however, there is no convenient way for at-home, continuous blood pressure measurements. In this paper, we investigate the potential of a wearable optical interrogator for passive, continuous and wireless transcutaneous blood pressure measurement via an implanted fiber Bragg Grating (FBG) sensor. We established that FBG signal does not get distorted while travelling through ex-vivo tissue and we have designed and validated a prototype of the optical interrogator.

Introduction: Weight regain following laparoscopic sleeve gastrectomy (LSG) is a common and challenging scenario. Minimally invasive options include anti-obesity glucagon-like peptide 1 (GLP1) agonists or revisional endoscopic sleeve gastroplasty (R-ESG). While GLP1 agonists are popular, their efficacy in LSG patients compared with R-ESG or controls with intact stomach is unclear. We share a real-world experience with GLP1 agonists & R-ESG for weight regain after LSG. Methods: This is a retrospective study of all adult patients with a history of LSG who were treated with Sub-Q Semaglutide or Tirzepatide or underwent R-ESG for weight regain at UCLA Health from Jan 2019 till Jan 2023. A propensity-matched control group of obese patients on GLP1 agonists with no prior bariatric surgery was identified. Primary outcomes included total body weight loss (TBWL%), excess weight loss (EWL%) and adverse events (AE) on follow-up. Secondary outcomes included changes in A1c and lipid panel. Results: The study groups included 68 (LSG+ GLP1), 20 (LSG + R-ESG), and 87 control patients. Results are presented [Table 1]. R-ESG patients were significantly younger than LSG+ GLP1 or control groups (45.2 vs 52.9 vs 51.6 yrs, P=0.03), respectively. There was no significant difference in patients baseline BMI, diabetes prevalence, %weight loss and regain after LSG, or medication dosage between groups. Difficulty with GLP1 refills was encountered in 31 LSG (45.6%) and 33 controls (37.9%). Regarding outcomes, R-ESG offered a significantly higher TBWL% than GLP1 agonists at three (10% vs 4.3%,P=0.0001) and six months (11.5% vs 6.8%, P=0.03) in LSG patients. GLP1 agonists achieved significantly lower TBWL% in LSG patients than controls at three (4.3% vs 5.7%,P=0.02), six (6.8% vs 9.2%,P=0.02), and twelve months (9.2% vs 12.7%, P=0.03). While LSG + R-ESG patients had significantly higher post-op abdominal pain than LSG+ GLP1 (10% vs 0%,P=0.04), there was no significant difference in other AE. No significant difference in the change of A1c (0.05 vs 0.6, P=0.06), LDL (-8 vs -1.1, P=0.56) or triglyceride levels (15.2 vs 27.6, P=0.59) was seen at 12 months in LSG+ R-ESG vs LSG+ GLP1, respectively. Conclusion: In a real-world experience, anti-obesity GLP1 agonists achieved significantly lower weight loss in LSG patients than those with intact stomach. R-ESG offered significantly higher weight loss than GLP1 agonists in LSG patients with weight regain while also avoiding the difficulties of GLP1 refills, making it an attractive option. Table 1. - Study Results LSG + GLP-1 agonists LSG + R-ESG Controls on GLP-1 Agonists (N= 68) (N= 20) (N=87) P value Baseline characteristics Age (years) 52.9 ± 11.9 45.2 ± 12.2 51.6 ± 11.5 0.03 Gender: Male 17 (25%) 6 (30%) 15 (17.2%) Female 51 (75%) 14 (70%) 72 (82.8%) 0.25 Ethnicity Caucasian 38 (55.9%) 9 (45%) 37 (42.5%) 0.13 Hispanic 18 (26.9%) 5 (25%) 18 (20.7%) 0.66 African American 8 (11.8%) 3 (15%) 11 (12.6%) 0.94 Asian 2 (2.9%) 0 (0%) 10 (11.5%) 0.05 Others 2 (2.9%) 3 (15%) 11 (12.6%) 0.07 Baseline BMI (Kg/m2) 43.9 ± 7 37.4 ± 6.1 39.3 ± 6.1 0.11 Obesity-related comorbidities: Essential hypertension 47 (69.1%) 12 (60%) 58 (66.7%) 0.75 GERD 40 (58.8%) 11 (55%) 27 (31%) < 0.01 Diabetes mellitus 30 (44.1%) 4 (20%) 39 (44.8%) 0.11 Hyperlipidemia 48 (70.6%) 8 (40%) 47 (54%) 0.02 Obstructive sleep apnea 48 (70.6%) 8 (40%) 30 (34.5%) < 0.001 Fatty liver disease 10 (14.7%) 2 (10%) 10 (11.5%) 0.78 Coronary artery disease 8 (11.8%) 2 (10%) 4 (4.6%) 0.25 Baseline hemoglobin A1c (%) 6.1 ± 1 5.7 ± 0.5 6.5 ± 1.4 0.04 Baseline LDL cholesterol (mg/dl) 102 ± 38 108 ± 31.2 101.1 ± 37.8 0.8 Baseline triglyceride (mg/dl) 121 ± 61 122.2 ± 96.6 158 ± 92 0.03 LSG data LSG + GLP-1 agonists (N=68) LSG + R-ESG (N=20) Controls on GLP-1 agonists (N=87) P value TBWL by LSG (%) 14.6 ± 9.1 14.6 ± 11.5 N/A 0.9 EWL by LSG (%) 30.4 ± 19 28.8 ± 25.1 N/A 0.7 Regained weight after LSG (%) 40.3 ± 40.3 53 ± 33.5 N/A 0.2 Months from LSG to intervention 52.4 ± 33.8 76 ± 39.4 N/A 0.003 Pharmacotherapy data LSG + GLP-1 agonists (N=68) LSG + R-ESG (N=20) Controls on GLP-1 agonists (N=87) P value Medication used: Semaglutide 59 (86.6%) N/A 78 (89.7%) 0.57 Tirzepatide 7 (10.3%) N/A 9 (10.3%) 0.99 Both alternated 2 (2.9%) N/A 0 (0%) 0.19 Weekly semaglutide dose (mg) 1.25 ± 0.6 N/A 1.19 ± 0.6 0.61 Weekly tirzepatide dose (mg) 7.5 ± 3.1 N/A 7.2 ± 2.9 0.85 Difficulties with refills 31 (45.6%) N/A 33 (37.9%) 0.33 Months on medication 9.3 ± 5.9 N/A 8.6 ± 4.8 0.67 Medication discontinuation 12 (17.6%) N/A 7 (8%) 0.07 Months to discontinuation 11.3 ± 10.9 12.4 ± 8.9 Outcomes LSG + GLP-1 agonists (N=68) LSG + R-ESG (N=20) P value Controls on GLP-1 agonists (N=87) P value TBWL% 3 months 4.3 ± 4 10 ± 5.8 0.0001 5.7 ± 3.6 0.02 6 months 6.8 ± 5.6 11.5 ± 6.5 0.03 9.2 ± 5.8 0.02 12 months 9.2 ± 7 10.8 ± 7.8 0.5 12.7 ± 6.8 0.03 EWL% 3 months 12.7 ± 12.9 27.5 ± 18.6 0.001 14.9 ± 10.6 0.25 6 months 18.5 ± 17.4 36 ± 20.4 0.001 22.8 ± 15.9 0.003 12 months 25.4 ± 20.7 32.1 ± 22.4 0.38 32.9 ± 20.1 0.12 Adverse events Nausea ± vomiting 14 (20.6%) 2 (10%) 0.28 9 (10.3%) 0.07 Constipation 0 (0%) 0 (0%) 1 3 (3.4%) 0.25 Abdominal pain 0 (0%) 2 (10%) 0.049 0 (0%) 1 Intra-op bleeding. N/A 0 (0%) N/A N/A N/A Intra-op perforation N/A 0 (0%) N/A N/A N/A Post-op admission N/A 1 (10%) N/A N/A N/A A1c% change 3 months 0.3 ± 0.5 0.07 ± 0.1 0.21 0.8 ± 1.2 0.07 6 months 0.2 ± 0.5 -0.08 ± 0.2 0.23 0.7 ± 0.8 0.009 12 months 0.6 ± 0.8 0.05 ± 0.3 0.06 0.6 ± 0.9 0.89 LDL change at 12 months -1.1 ± 28.7 -8 ± 23 0.56 15.6 ± 36 0.09 Triglyceride change at 12 months 27.6 ± 58.3 15.2 ± 43.1 0.59 30.3 ± 73.2 0.07 Statistics presented as mean (±SD) or frequency (%). P was calculated using chi-square test for categorical data & one-way ANOVA for numerical data. P < 0.05 was considered statistically significant. LSG: laparoscopic sleeve gastrectomy, GLP-1: glucagon-like peptide 1, R-ESG: revisional endoscopic sleeve gastroplasty, BMI: body mass index, GERD: gastroesophageal reflux disease, TBWL: total body weight loss, EWL: excess weight loss.

Introduction: Endoscopic bariatric therapy (EBT) has emerged as a minimally-invasive approach for weight loss in patients with and without a history of bariatric surgery. Pain is a common post-procedural complaint that may necessitate hospital admission, analgesia, and narcotics use, leading to increased cost and morbidity. Given the paucity of data in this area, we aimed to identify factors associated with increased post-procedural pain in a cohort of patients followed closely after EBT. Methods: This prospective study at 2 tertiary-care centers in the US evaluated adult patients undergoing primary endoscopic gastroplasty (ESG) and endoscopic revision from 4/2021 to 4/2023. Argon plasma coagulation (APC) was used following suturing in selected cases per endoscopists' discretion to induce scarring and improve durability. The primary outcome was the severity of post-procedural pain measured on a scale from 0 to 10. Mild pain was defined as pain levels 1-4, moderate as 5-7, and severe as 8-10. A z-test of proportions was used to compare proportions and a Student's t-test was used to compare continuous outcome variables. Results: Sixty-one patients underwent EBT for morbid obesity and were followed longitudinally to monitor post-procedural symptoms and treatment efficacy. Post-procedural pain was reported in 46/61 (75.4%) patients. The average severity of post-procedural pain was 3.1/10 ± 2.5. Twenty-two (36.1%) patients had mild pain, 7(11.5%) had moderate pain, and 17(27.9%) had severe pain (Table 1). 21/61 (34.4%) patients received opiates on discharge; the average duration of use was 7.3 ± 4.1 days. The use of concomitant APC was associated with greater severity of post-procedural pain (3.1 vs. 4.6, P=0.03). A history of irritable bowel syndrome (IBS) or visceral hypersensitivity was associated with worse pain level (2.9 vs. 5.8, P=0.04) in the ESG subgroup (Figure 1). Patients with no-to-mild pain had a lower number of bites-per-suture on average compared to patients with severe post-procedural pain (6.5 vs. 7.1, P< 0.01). A greater proportion of patients underwent primary ESG in the severe pain group (88.2% vs. 52.2%, P< 0.01). Conclusion: We identified the combination of suturing plus APC, number of bites-per-suture, and history of visceral hypersensitivity as risk factors for severe post-procedural pain following EBT. While pain was mild-to-moderate in most patients, identifying patients at risk for severe post-procedural pain is critical to facilitate recovery and prevent unplanned admission.Figure 1.: Average pain (scale 0 to 10) for those receiving APC and not receiving APC and for those patients with and without IBS. Table 1. - Summary statistics for patients receiving endobariatric treatments with subgroups for those with severe and non-severe pain Demographics Total (n=61) None-to-Mild Pain (n=44) Mod-to-Severe Pain (n=17) P-value Female, n (%) Age (years), mean (SD) 46 (75.4) 32 (72.7) 14 (82.4) 0.44 Race, n (%) 46.4 (10.8) 47.6 (9.9) 43.5 (12.7) 0.09 White 30 (60.6) 22 (50.0) 8 (47.0) 0.83 Black 7 (11.5) 5 (11.4) 2 (11.8) 0.97 Asian/Pacific Islander 1 (1.6) 1 (2.3) 0 0.53 American Indian 1 (1.6) 1 (2.3) 0 0.53 Other/Unknown 22 (36.1) 14 (38.1) 4 (23.5) 0.52 Procedural Data Procedure Type, n (%) Primary ESG 38 (62.3) 23 (52.2) 15 (88.2) < 0.01 Re-Sleeve 11 (18.0) 10 (22.7) 1 (5.9) 0.13 TORe-G 3 (4.9) 3 (6.8) 0 0.27 TORe with endoscopic suture 9 (14.7) 8 (18.2) 1 (5.9) 0.23 APC use, n (%) 35 (57.4) 21 (47.7) 14 (82.3) 0.01 Total Sutures, average (SD) 1st layer 5.4 (1.5) 5.6 (1.7) 5.2 (0.9) 0.40 2nd layer 2.6 (2.5) 2.6 (1.4) 2.6 (1.1) 0.92 Bites per Suture, average (SD) 6.7 (1.0) 6.5 (1.1) 7.1 (0.7) < 0.01 IBS*, n (%) 5 (8.2) 3 (6.8) 2 (11.7) 0.04 Pain Outcomes Pain severity, mean, SD 3.1 (2.5) 2.3 (2.2) 8.4 (0.80) < .001 Pain duration, days, SD 2.6 (2.7) 1.6 (1.4) 5.0 (3.7) .001 Hospital admission, n (%) 4 (6.6) 3 (6.8) 1 (5.9) 0.90 Opiates on discharge, n (%) 21 (34.4) 13 (29.5) 8 (47.1) 0.20 Duration of opiate use, days (SD) 7.3 (4.1) 7.3 (4.1) 7.3 (4.0) 0.28 *Data for IBS was available for only a subset of the total patients (n=42). ESG; endoscopic sleeve gastroplasty, TORe-G; transoral outlet reduction with gastroplasty, TORe; transoral outlet reduction, APC; argon plasma coagulation, IBS; irritable bowel syndrome.

Currently, there are differences in both demographics and indications for bariatric surgery between Eastern and Western countries. We compared postoperative outcomes between Korean and American bariatric programs in order to assess how bariatric surgery differently affects these populations. We enrolled 540 patients who underwent bariatric surgery at University of California, Los Angeles (UCLA) and 85 patients who underwent surgery at Kosin University Gospel Hospital (KUGH) between January 2019 and December 2020. We compared demographics, complications, weight loss, and metabolic parameters between these groups. There was a difference in age between the UCLA and KUGH patient groups (44.3 years vs 37.6 years, P < 0.01). Frequencies of T2DM and OSA were also different (4.2

Background and aims:Peroral endoscopic myotomy uses a submucosal tunnel that staggers the esophageal mucosotomy and myotomy, allowing minimally invasive interventions in the esophagus to treat achalasia. Our goal was to assess the feasibility of this method to access the mediastinum to perform endoscopic epicardial access and pericardial window in a porcine model. Methods:Experiments were conducted to assess the feasibility of this procedure. Commonly available ERCP and EUS instruments were used to show epicardial access under both direct transesophageal mediastinoscopic visualization and EUS guidance. Results:In experiments, we successfully placed catheters in the pericardial space without hemodynamic instability or adverse events. A pericardial window was performed in other experiments, draining the instilled simulated pericardial effusion. Conclusion:Transesophageal epicardial access and pericardial window seemed to be feasible and well tolerated in a porcine model, indicating the possibility of expanding mediastinal procedures conducted with endoscopy in the future.

Bariatric surgery remains a potent therapy for nonalcoholic fatty liver disease (NAFLD), but its inherent risk and eligibility requirement limit its adoption. Therefore, understanding how bariatric surgery improves NAFLD is paramount to developing novel therapeutics. Here, we show that the microbiome changes induced by sleeve gastrectomy (SG) reduce glucose-dependent insulinotropic polypeptide (GIP) signaling and confer resistance against diet-induced obesity (DIO) and NAFLD. We examined a cohort of NALFD patients undergoing SG and evaluated their microbiome, serum metabolites, and GI hormones. We observed significant changes in Bacteroides, lipid-related metabolites, and reduction in GIP. To examine if the changes in the microbiome were causally related to NAFLD, we performed fecal microbial transplants in antibiotic-treated mice from patients before and after their surgery who had significant weight loss and improvement of their NAFLD. Mice transplanted with the microbiome of patients after bariatric surgery were more resistant to DIO and NAFLD development compared to mice transplanted with the microbiome of patients before surgery. This resistance to DIO and NAFLD was also associated with a reduction in GIP levels in mice with post-bariatric microbiome. We further show that the reduction in GIP was related to higher levels of Akkermansia and differing levels of indolepropionate, bacteria-derived tryptophan-related metabolite. Overall, this is one of the few studies showing that GIP signaling is altered by the gut microbiome, and it supports that the positive effect of bariatric surgery on NAFLD is in part due to microbiome changes.

Introduction: Despite substantial evidence for the safety and efficacy of endoscopic bariatric therapy (EBT) for weight loss, insurance coverage remains remarkably limited in the United States. Insurance reimbursement is an important determinant of patients’ access to care, as well as physicians’ compensation. We aimed to identify demographic, clinical, and procedural factors associated with insurance coverage for patients undergoing EBT. Methods: We performed a retrospective review of patients who underwent EBT for the treatment of obesity at a tertiary-care referral center between Jan 2020 and May 2023. All patients who received insurance coverage were included. Cash-pay patients were excluded. A control cohort of eligible patients denied by insurance was studied. The primary objective was to identify predictors for successful prior authorization and coverage. Secondary outcomes included the proportion of procedural costs covered by insurance. Results: A total of 158 patients were included (124 successfully received insurance coverage for EBT, and 34 controls with denied prior authorization) (Table 1). Among commercially available insurers, percentage of patients insured with Blue Shield (P< 0.0001) and Cigna Healthcare (P= 0.03) were significantly lower in the covered group compared to the denied authorization group {7% vs 38.2%, 1.6% vs 8.8%; respectively). No difference was found in the insurance coverage rate based on BMI > 30 kg/m2 alone, BMI >30 kg/m2 + 1 comorbidity, BMI 30 kg/m2 + 2 comorbidities, presence of diabetes, age, or gender. Significantly greater coverage was seen for patients undergoing revisional procedures compared to primary EBT (87.1% vs. 18.5%, respectively; P< 0.001). In a subgroup analysis performed for 57 ESG patients (Table 1), Cigna Healthcare had the lowest approval rate; however, no predictive clinical or demographic factors were found to predict better insurance approval for ESG. Conclusion: Revisional endoscopic procedures received better insurance coverage than primary endoscopic therapy. Although we identified two commercial insurers more frequently denied coverage in our cohort, no other predictive factors could be determined. These results indicate a lack of standardization and the state of outdated insurance policies that do not reflect the current efficacy data for ESG. As the need for less-invasive treatments for obesity grows larger, so does the critical appeal for expanded, transparent coverage of these treatments. Table 1. - Descriptive statistics for full cohort of patients either receiving insurance authorization for endobariatric therapy or denial (top), as well as subset of patients receiving authorization specifically for primary endoscopic sleeve gastroplasty or denial (bottom) Demographics Authorized (N=124) Denied (N=34) P-value Female, n (%) 99 (79.8) 27 (79.4) 0.96 Age, mean years (SD) 49.5 (10.9) 50.2 (12.0) 0.75 White, n (%) 69 (55.6) 9 (26.5) < .01 Black, n (%) 25 (20.2) 1 (2.9) 0.02 Hispanic, n (%) 18 (15.8) 5 (14.7) 0.98 Asian/Pacific Islander, n (%) 3 (2.4) 2 (5.8) .31 Other/Unknown, n (%) 10 (8.1) 17 (50.0) <.001 Clinical Characteristics BMI, mean (SD) 39.3 kg/m2 (6.8) 38.7 kg/m2 (10.0) 0.72 BMI > 35 kg/m2, n (%) 90 (72.6) 21 (61.8) 0.22 BMI > 30 + 1 comorbidity 116 (93.5) 31 (91.1) 0.63 BMI > 30 + 2 comorbidities 108 (87.1) 29 (85.3) 0.79 T2DM, n (%) 36 (29.0) 11 (32.4) 0.70 Procedural Characteristics Procedure performed ESG, n (%) 23 (18.5) - - Re-sleeve 21 (16.9) - - TORe, n (%) 43 (34.7) - - TORe-G, n (%) 34 (27.4) - - APC-TORe, n (%) 3 (24.2) - - Previous Surgery Any, n (%) 108 (87.1) 7 (20.6) < .001 RYGB 81 (65.3) 3 (0.9) < .001 Sleeve gastrectomy 21 (16.9) 0 0.01 Gastric Band 5 (4.0) 1 (2.9) 0.77 IGB 0 2 (5.8) 0.01 Coverage Details Procedure cost 100% covered, n (%) 32 (25.8) - - Mean copay by patient, $ (SD) 632.28 (1,017.0) - Insurance Characteristics Payor Anthem Blue Cross, n (%) 47 (40.9) 13 (38.2) 0.97 Blue Shield of California, n (%) 8 (7.0) 13 (38.2) < 0.0001 Medicare, n (%) 13 (11.3) 1 (2.9) 0.17 United Healthcare, n (%) 15 (13.0) 2 (5.9) 0.30 Cigna Healthcare, n (%) 2 (1.6) 3 (8.8) 0.03 Endoscopic Sleeve Gastroplasty Cohort Demographics Authorized for ESG (N=23) Denied (N=34) P-value Female, n (%) 16 (79.8) 27 (79.4) 0.14 Age, mean years (SD) 43.8 (10.9) 50.2 (12.0) 0.06 White, n (%) 11 (55.6) 9 (26.5) 0.10 Black, n (%) 2 (20.2) 1 (2.9) 0.95 Hispanic, n (%) 3 (15.8) 5 (14.7) 0.86 Asian/Pacific Islander, n (%) 0 (2.4) 2 (5.8) 0.24 Other/Unknown, n (%) 7 (8.1) 17 (50.0) 0.14 Clinical Characteristics BMI, mean (SD) 40.8 kg/m2 (8.2) 38.7 kg/m2 (10.0) 0.40 BMI > 35 kg/m2, n (%) 14 (60.9) 21 (61.8) 0.94 BMI > 30 + 1 comorbidity 19 (82.6) 31 (91.1) 0.33 BMI > 30 + 2 comorbidity 15 (65.2) 29 (85.3) 0.08 T2DM, n (%) 9 (39.1) 11 (32.4) 0.60 Insurance Characteristics Payor, n (%) Anthem Blue Cross 4 (17.4) 13 (38.2) 0.09 Medicare 2 (8.7) 1 (2.9) 0.34 United Healthcare 4 (17.4) 2 (5.9) 0.16 Blue Shield of California, 1 (4.3) 3 (8.8) 0.52 Cigna Healthcare 0 3 (8.8) 0.14 Others 4 (17.4) 0 0.01 P-values represents results from z-test for proportions or t-test. ESG; endoscopic sleeve gastroplasty, BMI; body mass index, T2DM; type 2 diabetes mellitus, TORe; transoral outlet reduction. TORe-G; transoral outlet reduction with gastroplasty, APC; argon plasma coagulation, RYGB; Roux-en-Y gastric bypass, IGB; intragastric balloon.

Introduction: Anesthesia management for endoscopic bariatric therapies, such as transoral outlet reduction (TORe) for patients with weight gain after prior gastric bypass surgery, typically consists of endotracheal intubation using either total intravenous anesthesia (TIVA) (i.e. propofol sedation) or inhalation anesthetics (GAS). TIVA is associated with faster recovery times and fewer side effects than GAS for many procedures, but providers may opt against TIVA for patients with obesity due to concerns about dosing or volume of distribution. It is also unknown whether the advantages of TIVA apply to patients with obesity specifically undergoing a relatively short bariatric procedure such as TORe. We therefore aimed to compare sedation related adverse events (SRAEs) and recovery in patients who received TIVA or GAS for TORe. Methods: This was a retrospective study of consecutive patients who underwent TORe at a tertiary care center between July 2020 and October 2022 for obesity or weight regain after gastric bypass surgery. Intraprocedural and postprocedural SRAEs, defined as hypoxia (O2 saturation < 85% of any duration), hypotension (systolic blood pressure < 90 mmHg requiring vasopressors), cardiac arrhythmias, or premature termination of endoscopy were measured. Post-procedure nausea/vomiting, analgesic use, and recovery time were also assessed. Results: Of 107 total TORe procedures, TIVA was used in 47 cases verses GAS in 60 cases. There were no significant differences in demographics, BMI, or ASA score (Table 1) between groups. SRAEs occurred in 19% of TIVA procedures and 23% of GAS procedures (Figure 1). After controlling for age, gender, and BMI in regression analysis, there was no significant difference in SRAEs between the 2 groups (OR 0.65; CI 0.25-1.70). Patients who received TIVA had significantly shorter recovery times (185 min vs 225 min; P=0.04). There was no significant difference in anesthesia duration, post-op nausea/vomiting, or unplanned admission rates. There were no premature procedure terminations, cardiac arrests, or deaths. Conclusion: TIVA and GAS appear to have similar safety and recovery profiles for patients undergoing TORe, while the use of TIVA was associated with faster recovery of nearly 40 minutes. Either form of sedation may be appropriate for TORe when combined with careful patient selection, good communication, and planning between the endoscopist and anesthesiology team.Figure 1.: Sedation related adverse events and post-procedure nausea and vomiting. Table 1. - Baseline demographics and patient outcomes Characteristics TIVA group (n = 47) GAS group (n = 60) P value Age (years) 50.7 (±11.7) 50.1 (±9.8) 0.76 Gender Female 40 (85.1%) 49 (81.7%) 0.64 Male 6 (12.8%) 11 (18.3%) 0.43 Other 1 (2.1%) 0 0.26 Ethnicity Hispanic or Latino 6 (12.8%) 9 (15.0%) 0.74 Not Hispanic or Latino 39 (83.0%) 48 (80.0%) 0.69 Unknown 2 (4.2%) 3 (5.0%) 0.86 BMI (kg/m2) 39.3 39.12 0.93 ASA Class 2.79 2.75 0.71 Primary outcome Sedation related adverse events 9 (19.2%) 15 (25.0%) 0.38 Hypotension 8 (17.0%) 7 (11.7%) 0.33 Arrhythmia 1 (2.1%) 7 (11.7%) 0.07 Hypoxia 0 (0%) 1 (1.7%) 0.49 Premature termination of endoscopy 0 (0%) 0 (0%) N/A Secondary outcomes Anesthesia duration (min) 75.7 74.92 0.98 Recovery duration (min) 185.2 224.5 0.04 Intra-procedure pain medication 33 (70.2%) 44 (73.3%) 0.69 Intra-procedure anti-emetics 41 (87.2%) 57 (95.0%) 0.15 Intra-procedure PPI/H2 blocker 20 (42.6%) 14 (23.3%) 0.03 Recovery pain medication 16 (34.0%) 24 (40.0%) 0.49 Recovery anti-emetics 24 (51.1%) 32 (54.2%) 0.55 Recovery PPI/H2 blocker 3 (6.4%) 6 (10.0%) 0.52 Same day discharge 44 (93.6%) 58 (96.7%) 0.50

Haptic feedback relays important tissue mechanical properties to surgeons during open surgery. However, this information is lost during Robot-assisted Minimally Invasive Surgery (RMIS). Here we present a proof-of-concept for a novel instrument-integrated sensor that uses fiber Bragg grating (FBG) arrays to identify tissues based on mechanical properties. Subjects were tasked with sorting tissue phantoms based on hardness. When using a conventional surgical robot, the average error for novices (N=5) and the expert user was 22.5% and 12.5% respectively. This reduced to 2.5% and 0% when sorting with direct palpation by hand. In contrast, the senorized instrument with automated analysis was able to perform the task without any error across all trials. Clinical Relevance - The proposed sensor has the potential of identifying different tissues based on mechanical properties and thus characterize tumors and other relevant structures. It is envisaged that this will improve decision making process during RMIS and also provide useful sensory information for autonomous surgery.

Gastrojejunostomy (GJ) stricture is one of the most commonly recognized complications following laparoscopic Roux-en-Y gastric bypass (LRYGB). The risks involving the formation of early GJ stomal stenosis are largely unknown. The aims of this study are to evaluate the rate and risk factors associated with GJ stricture in patients requiring esophagogastroduodenoscopy (EGD) within 30 days after LRYGB. This is a retrospective study of patients who underwent EGD for GJ stricture following LRYGB. Data were retrieved from MBSAQIP database from 2015 to 2018. Descriptive, bivariate, and logistic regression analyses were performed. Those who had reoperation, readmission, and intervention for other indications rather than GJ stricture were excluded from the risk factor analysis. 760,076 patients underwent bariatric surgery. Of these, 184,660 (24.3%) underwent LRYGB and 875 had GJ stricture within 30 days postoperatively. The overall incidence of early GJ stricture after LRYGB was 4.7 per 1000 person-years. The incidence decreased from 6.2 to 3.4 per 1000 person-years during the 4-year period. 85% of patients with GJ stricture required therapeutic intervention. Median (IQR) day to the first endoscopic intervention was 25 (21–28) days. The overall 30-day readmission rate was 40%. 30-day reoperation rate due to GJ stricture was 5.6%. No 30-day mortality occurred. Factors independently associated with an increased risk for early GJ stricture include concurrent hiatal hernia repair (Adjusted Odds Ratio—AOR 1.8, 95% CI 1.5–2.2), revision case (AOR 1.4, 95% CI 1.1–1.6), African American (AOR 1.4, 95% CI 1.2–1.7), gastroesophageal reflux disease—GERD (AOR 1.4, 95% CI 1.2–1.5), drain placement (AOR 1.3, 95% CI1.1–1.4), and routine postoperative swallow study (AOR 1.3, 95% CI 1.1–1.50). The incidence of early GJ stricture following LRYGB decreased at MBSAQIP-accredited centers over the review period. Patients having additional manipulation at or around GJ were at risk of developing early GJ stricture after LRYGB.

Excessive tissue–instrument interaction forces during robotic surgery have the potential for causing iatrogenic tissue damages. The current in vivo study seeks to assess whether tactile feedback could reduce intraoperative tissue–instrument interaction forces during robotic-assisted total mesorectal excision. Five subjects, including three experts and two novices, used the da Vinci robot to perform total mesorectum excision in four pigs. The grip force in the left arm, used for retraction, and the pushing force in the right arm, used for blunt pelvic dissection around the rectum, were recorded. Tissue–instrument interaction forces were compared between trials done with and without tactile feedback. The mean force exerted on the tissue was consistently higher in the retracting arm than the dissecting arm (3.72 ± 1.19 vs 0.32 ± 0.36 N, p < 0.01). Tactile feedback brought about significant reductions in average retraction forces (3.69 ± 1.08 N vs 4.16 ± 1.12 N, p = 0.02), but dissection forces appeared unaffected (0.43 ± 0.42 vs 0.37 ± 0.28 N, p = 0.71). No significant differences were found between retraction and dissection forces exerted by novice and expert robotic surgeons. This in vivo animal study demonstrated the efficacy of tactile feedback in reducing retraction forces during total mesorectal excision. Further research is required to quantify the clinical impact of such force reduction.

Suturing is required in almost all surgeries but it is challenging to perform with surgical robots due to limited vision and/or haptic feedback. To tackle this problem, we present an autonomous suturing framework that encompasses a novel needle path planner, as well as an accurate needle pose estimator and a six degrees-of-freedom controller. A novel needle grasper is developed that enables needle pose estimation both inside and outside the tissue. The framework was evaluated experimentally using the Raven IV surgical system and important suture parameters were quantified. The experiment results confirmed a needle pose estimation accuracy of < 0.87 mm in position and < 3.46. in orientation across all directions. Moreover, the results revealed that using the proposed framework enabled following the reference needle trajectories with errors of 2.07 mm in position and 4.29. in orientation. These are drastic improvements of more than 10x in position and 5x in orientation compared to the Raven IV kinematic controller. Additionally, the results verified that our framework delivered the desired clinical suture parameters successfully across tissue phantom environments with different mechanical properties and under various needle trajectories. A supplementary video can be found at: http://bionics.seas.ucla.edu/ research/surgeryproject18. htmlhttp://bionics.seas.ucla.edu/research/ surgeryproject18

Adding haptic feedback has been reported to improve the outcome of minimally invasive robotic surgery. In this study, we seek to determine whether an algorithm based on simulating responses of a cutaneous afferent population can be implemented to improve the performance of presenting haptic feedback for robot-assisted surgery. We propose a bio-inspired controlling model to present vibration and force feedback to help surgeons localize underlying structures in phantom tissue. A single pair of actuators was controlled by outputs of a model of a population of cutaneous afferents based on the pressure signal from a single sensor embedded in surgical forceps. We recruited 25 subjects including 10 expert surgeons to evaluate the performance of the bio-inspired controlling model in an artificial palpation task using the da Vinci surgical robot. Among the control methods tested, the bio-inspired system was unique in allowing both novices and experts to easily identify the locations of all classes of tumors and did so with reduced contact force and tumor contact time. This work demonstrates the utility of our bio-inspired multi-modal feedback system, which resulted in superior performance for both novice and professional users, in comparison to a traditional linear and the existing piecewise discrete algorithms of haptic feedback.