Enhancing Lymph Node Yield in Gastric Cancer Resection: Impact of Back Table Dissection on Number of Lymph Node Examined.

INTRODUCTION: During gastric cancer resection, back table dissection (BTD) involves examination and separation of lymph node (LN) packets from the surgical specimen based on LN stations, which are sent to pathology as separately labeled specimens. With potential impact on clinical outcomes, we aimed to explore how BTD affects number of LNs examined. METHODS: A retrospective review of a gastric cancer database was performed, including all cases of gastrectomy with D2 lymphadenectomy from January 2009 to March 2022. Back table dissection and conventional groups were compared using Mann-Whitney U and Fisher's exact tests. Multiple linear regression modeling was used to identify potential predictors of number of LN examined. RESULTS: A total of 174 patients were identified: 39 (22%) BTD and 135 (78%) conventional. More patients in the BTD group underwent neoadjuvant chemotherapy (62% vs 29%, P < .05). Compared to the conventional group, the BTD group had a greater number of LNs examined (42 [26-59] vs 21[15-33], median [IQR], P < .001), lower LN positivity ratio (.01 vs .07, P = .013), and greater number of LNs in patients with BMI >35 (32.5[27.5-39] vs 22[13-27], P = .041). A multiple linear regression model controlling for age, BMI, preoperative N stage, neoadjuvant chemotherapy, surgeon experience, and operative approach identified BTD as a significant positive predictor of number of LN examined (ß = 19.7, P = .001). CONCLUSION: Back table dissection resulted in improved LN yield during gastric cancer resection. As a simple technical addition, BTD helps enhance pathology examination and improve surgeon awareness, which may ultimately translate to improve oncologic outcomes.

Teaching endoscopic management of gastrointestinal hemorrhage using a modular simulation curriculum.

BACKGROUND: As flexible endoscopy is increasingly adopted as a minimally invasive approach to surgical challenges, an efficient curriculum is needed to train surgeons in therapeutic endoscopy. We developed a simulation-based approach to teaching endoscopic management of gastrointestinal hemorrhage as part of a modular curriculum, complete with task performance pre- and post-testing. METHODS: Two sessions of our advanced flexible endoscopy course were taught using ex vivo porcine models to simulate active gastrointestinal hemorrhage and allow for training in hands-on endoscopic management. The module is composed of hands-on pretesting, didactics, mentored practice sessions, and postcourse assessments. Pre- and postcourse tests and surveys evaluated knowledge, confidence, and performance of participants and results were analyzed using the paired t test. RESULTS: Sixteen practicing surgeons participated in the course. After course completion, overall knowledge-based assessments improved from 3.4 (±1.9) to 5.8 (±2.0) (P < .001). Although participants with glove sizes >7.0 and ≥2 years in practice had higher pretest evaluator scores (P = .045 and P = .020), all participants demonstrated overall improvement in endoscopic management of hemorrhage, with postcourse evaluator score increases from 20.9 (±1.6) to 23.6 (±2.0) (P = .001) and specific improvements in identification of target bleeding (P = .015), endoscopic clip setup (P < .001), and clip deployment (P = .002). Surveys also found increased confidence in competency after curriculum completion, 11.6 (±3.4)-23.0 (±5.5) (P < .001). CONCLUSION: Our simulation-based approach to teaching the endoscopic management of gastrointestinal bleeding emphasizes hands-on pretesting and provides an effective training model to improve the knowledge, confidence, and technical performance of practicing surgeons.

"Into the fire" approach to teaching endoscopic foreign body removal using a modular simulation curriculum.

BACKGROUND: As flexible endoscopy becomes an increasingly valuable minimally invasive approach to surgical challenges, an efficient and comprehensive training curriculum is needed to train surgeons in therapeutic endoscopy. We developed a modular curriculum utilizing a simulation-based, "into the fire" approach to endoscopic foreign body removal for practicing physicians with task performance pre- and post-testing. METHODS: From 2020 to 2021, two sessions of our advanced flexible endoscopy course were taught by two expert surgical endoscopists using ex-vivo porcine models. The course focused on safe removal techniques for various foreign bodies as part of an overall endoscopy curriculum that uses hands-on simulation-based pre-testing, didactics, and mentored practice sessions, followed by post-course examination. Pre- and post-course assessments and surveys were used to evaluate knowledge, performance, and confidence of participants, and subsequently analyzed using the Wilcoxon-signed rank test. RESULTS: Of the 16 practicing physicians who participated in the course, 43.8% were certified in Fundamentals of Endoscopic Surgery, and 62.5% had completed > 200 prior upper endoscopies. Upon course completion, scoring on knowledge-based written examinations improved from 3.4 ± 1.9 to 5.8 ± 2.0 (p < 0.001). Technical facility of each participant demonstrated significant overall improvement with post-course score increased from 15.8 ± 2.5 to 23.6 ± 1.6 (p < 0.001), with skill refinement noted in technical subcategories of appropriate instrument use (p < 0.001), foreign body manipulation (p < 0.001), and successful foreign body removal (p < 0.001). Confidence surveys likewise demonstrated significant increase in confidence after completion of the curriculum 11.6 ± 3.4 to 23.0 ± 5.5 (p < 0.001). CONCLUSIONS: The "into the fire" approach to teaching endoscopic foreign body removal utilizing our simulation module provides an effective curriculum to improve knowledge, confidence, and overall technical performance. Our methodology utilizes hands-on, simulation-based pre-testing prior to instruction. This introduces clinical scenarios and technical challenges, while accounting for and tailoring to provider-specific variation in knowledge and experience, facilitating training efficiency.

A Tailored Approach to Laparoscopic Fundoplication: Outcomes in Patients with Esophageal Dysmotility.

BACKGROUND: Esophageal dysmotility is a common finding in patients being evaluated for antireflux surgery, although its implication remains unclear. We aimed to evaluate outcomes of patients with esophageal dysmotility after fundoplication. METHODS: A retrospective review of a prospective quality-database was performed. All patients who underwent laparoscopic Nissen (NF) or Toupet (TF) fundoplication were included. Esophageal dysmotility was defined using the Chicago Classification v4.0 and conventional metrics, creating three sub-groups: ineffective esophageal motility (IEM), distal/diffuse esophageal spasm (DES), and hypercontractile esophagus (HE). Quality of life (QOL) outcomes were measured by the Reflux Severity Index (RSI), Gastroesophageal Reflux Disease-Health Related Quality of Life (GERD-HRQL), and Dysphagia Scores. RESULTS: Of 487 patients included, 99 (20.3%) had esophageal dysmotility (49 IEM, 40 DES, 10 HE). While a majority in the dysmotility group (81.8%) underwent TF, most patients in the normal group (76.5%) underwent NF (p < 0.001). On multivariable analysis controlling for sex, age, BMI, hiatal hernia, and surgery type, the normal group had higher Dysphagia Scores at 3 weeks (2.2 ± 0.9 vs. 1.7 ± 0.8, p < 0.001), but not at 6-month, 1-year, 2-year, or 5-year follow-up. There were no differences between normal and dysmotility groups in terms of RSI or GERD-HRQL scores at any time point. Patients with different sub-types of esophageal dysmotility had similar QOL outcomes at all time points. CONCLUSION: Patients with esophageal dysmotility had similar outcomes compared to those with normal motility after fundoplication, suggesting the tailored approach favoring partial fundoplication for patients with dysmotility as part of an appropriate treatment algorithm.

Identification of 14 novel susceptibility loci for diaphragmatic hernia development and their biological and clinical implications: results from the UK Biobank.

INTRODUCTION: Genetic contributions to hernia development are incompletely understood. This study performed the first comprehensive genome-wide association study (GWAS) for diaphragmatic hernia using a large population-based cohort in the UK Biobank (UKB). METHODS AND PROCEDURES: Two-stage GWAS (discovery and confirmation) was performed for diaphragmatic hernia in the UKB. Briefly, 275,549 and 91,850 subjects were randomly selected for association tests in Stages 1 and 2, respectively. Association tests between 8,568,156 SNPs (genotyped or imputed with MAF > 0.01) in the autosomal genome and diaphragmatic hernia were performed in Stage 1. SNPs with P < 1 × 10-5 were selected for confirmation in Stage 2, and those with P < 0.05 and the same direction of association as Stage 1 were selected for combined association testing; SNPs with combined P < 5 × 10-8 were considered GWAS-significant. LD clumping analysis identified genetically independent chromosomal regions (loci). A genetic risk score (GRS) measured the cumulative risk of independent SNPs in 91,849 additional subjects using odds ratios (ORs) from Stages 1 and 2. RESULTS: 36,351 patients were identified with diaphragmatic hernia (ICD-10 K44). In Stage 1 analysis, 2654 SNPs were associated (P < 1 × 10-5) with diaphragmatic hernia. Stage 2 analysis confirmed 338 SNPs (P < 0.05). In combined analysis, 245 SNPs reached GWAS significance (P < 5 × 10-8). LD clumping analysis revealed 14 independent loci associated with diaphragmatic hernia. Two loci have been previously associated with inguinal hernia at 2p16 (rs181661155) and 11p13 (rs5030123). eQTL analysis suggested genes CRLF1, UBA52, and CALD1 are also significantly associated with these loci. GRS showed significant increase in cases compared to controls (P < 1 × 10-16) and is associated with increased risk of diaphragmatic hernia (P < 1 × 10-7). CONCLUSIONS: We identified 245 SNPs at 14 susceptibility loci associated with diaphragmatic hernia in a large population-based cohort. These results offer insight into pathogenetic mechanisms of diaphragmatic hernia development and may be used in genetic risk scores for pre-operative risk-stratification and clinical prediction models.

Impedance Planimetry (Endoflip) and Ideal Distensibility Ranges for Optimal Outcomes after Nissen and Toupet Fundoplication.

BACKGROUND: Previous research has shown that impedance planimetry-based functional lumen imaging probe (FLIP) measurements are associated with patient-reported outcomes after laparoscopic antireflux surgery. We hypothesize that Nissen and Toupet fundoplications have different ideal FLIP profiles, such as distensibility. STUDY DESIGN: A retrospective review of a prospectively maintained quality database was performed. Patients who had FLIP measurements during fundoplications between 2013 and 2021 were included. Reflux Symptom Index, Gastroesophageal Reflux Disease-Health Related Quality of Life Questionnaire, and dysphagia score were collected for up to 2 years postoperatively. The Wilcoxon rank-sum test was used to compare FLIP measurements vs outcomes. RESULTS: Two hundred fifty patients (171 Toupet, 79 Nissen) were analyzed. Distensibility ranges were categorized as tight, ideal, or loose. The ideal distensibility index range of Toupet patients with the 30- and 40-mL balloon fills were 2.6 to 3.7 mm2/mmHg. This range was associated with less dysphagia at 1 year compared with the tight group (p = 0.02). For Nissen patients, the 30- and 40-mL ideal threshold was a distensibility index of ≥2.2 mm2/mmHg. Patients with distensibility exceeding this threshold had a better quality of life than the tight group, reporting better Gastroesophageal Reflux Disease-Health Related Quality of Life Questionnaire (p = 0.02) and lower dysphagia scores (p = 0.01) at 2 years. CONCLUSIONS: Impedance planimetry revealed different ideal distensibility ranges after Toupet and Nissen fundoplications that are associated with improved patient-reported outcomes, suggesting that intraoperative FLIP has the potential to tailor fundoplication.

Changes in impedance planimetry (EndoFLIP) measurements at follow-up after peroral endoscopic myotomy (POEM).

BACKGROUND: Numerous studies show changes in functional lumen imaging probe (FLIP) measurements after myotomy during peroral endoscopic myotomy (POEM), but few report on FLIP measurements at follow-up esophagogastroduodenoscopy (EGD). The purpose of this study was to compare perioperative FLIP measurements to those at follow-up EGD. METHODS: Patients who underwent POEM with FLIP in the operating room and POEM patients who had EGD with FLIP at follow-up were included. FLIP measurements, including diameter (Dmin), pressure, cross-sectional area (CSA), and distensibility index (DI), were analyzed at a 30-mL balloon fill. Differences between measurements at different timepoints were assessed using a two-tailed Wilcoxon signed-rank test. RESULTS: A total of 97 patients who underwent POEM and 28 who underwent EGD with FLIP were analyzed. The average age was 63 ± 18 years and 46.4% of the patients were male. Mean preoperative Eckardt score was 6.5 ± 4.8, decreasing to 1.6 ± 2.0 at follow-up. EGDs were performed at a median of 15 months after surgery. When compared to mean measurements obtained post-myotomy, at the time of EGD, pressure was found to be significantly lower (p = 0.007) and DI significantly higher (p = 0.045). Of the patients who underwent EGD, 70.8% had an increase in DI, 55.6% had evidence of reflux esophagitis, and 81.0% met diagnostic criteria for reflux on esophageal pH monitoring. However, there was no correlation with the development of esophagitis or reflux and increase or decrease in DI at follow-up. CONCLUSIONS: There are significant changes in FLIP measurements between the time of surgery and at follow-up EGD. These results suggest that esophageal remodeling may cause changes in lower esophageal sphincter geometry after POEM and postoperative FLIP targets immediately post-myotomy may need to be adjusted to account for these changes.

Resident performance in simulation module is associated with operating room performance for laparoscopic cholecystectomy.

BACKGROUND: Simulation is an important tool in surgical training. However, the transferability of skills obtained in the simulation setting to the operating room (OR) is uncertain. This study explores the association between resident simulation performance and OR performance in a laparoscopic cholecystectomy (LC) simulation module. METHODS: A simulation module focused on LC utilizing a virtual reality simulator was completed by general surgery residents. Simulation performance was evaluated using the validated Global Operative Assessment of Laparoscopic Skills (GOALS) and Objective Structured Assessment of Technical Skills (OSATS), as well as a LC-specific simulation assessment form (LC-SIM). Resident subsequent OR performances of LC were measured by the Surgical Training and Assessment Tool (STAT), an online mobile-based evaluation completed by attending surgeons. RESULTS: Twenty-one residents who completed the simulation module and also with STAT data on LC from 2016 to 2020 were included. Higher scores on incision/port placement on LC-SIM is associated with better tissue handling (coefficient 0.20, p = 0.048) and better time & economy of motion on STAT (coefficient 0.22, p = 0.037). However, higher scores on time and motion on OSATS are associated with worse tissue handling (- 0.28, p = 0.046), worse time & economy of motion (- 0.37, p = 0.009), and worse overall grade (- 0.21, p = 0.044). Higher scores on overall performance on OSATS is associated with worse time & economy of motion (- 0.80, p = 0.008). Higher scores on depth perception on GOALS are associated with worse tissue handling (- 0.28, p = 0.044). CONCLUSION: We found significant positive and negative associations between resident simulation performance and OR performance, particularly in tissue handling and economy of motion. This could suggest that simulation performance does not reliably predict OR performance. However, this could highlight the concept of excessive caution in the real OR environment and longer operative time which could be interpreted as worse time and economy of motion by the attending surgeons.

Subjective vs. objective assessment of simulation performance on laparoscopic cholecystectomy: are we evaluating the right things?

BACKGROUND: Simulation using virtual reality (VR) simulators is an important tool in surgical training. VR laparoscopic simulators can provide immediate objective performance assessment without observer evaluation. This study aims to explore the correlation between subjective observer evaluation and VR laparoscopic simulator performance metrics in a laparoscopic cholecystectomy (LC) simulation module. METHODS: A LC simulation module using a VR laparoscopic simulator was completed by PGY2-3 general surgery residents at a single institution. Simulation performance was recorded and evaluated by a trained evaluator using the validated Global Operative Assessment of Laparoscopic Skills (GOALS) form, the Objective Structured Assessment of Technical Skills (OSATS) form, and a LC-specific simulation assessment form (LC-SIM). Objective performance metrics were also obtained from the simulator system. Performance before the curriculum (pre-test) and after the curriculum (post-test) were compared. RESULTS: Fourteen residents were included in the study. There were significant improvements from pre-test to post-test on each component of GOALS, OSATS, and LC-SIM scores (all p values < 0.05). In terms of objective simulator metrics, significant improvements were noted in time to extract gallbladder (481 ± 221 vs 909 ± 366 min, p = 0.019), total number of movements (475 ± 264 vs 839 ± 324 min, p = 0.012), and total path length (955 ± 475 vs 1775 ± 632 cm, p = 0.012) from pre-test to post-test. While number of movements and total path lengths of both hands decreased, speed of right instrument also decreased from 4.1 + 2.7 to 3.0 ± 0.7 cm/sec (p = 0.007). Average speed of left instrument was associated with respect for tissue (r = 0.60, p < 0.05) and depth perception (r = 0.68, p < 0.05) on post-test evaluations. CONCLUSION: Our study demonstrated significant improvement in technical skills based on subjective evaluator assessment as well as objective simulator metrics after simulation. The few correlations identified between the subjective evaluator and the objective simulator assessments suggest the two evaluation modalities were measuring different aspects of the technical skills and should both be considered in the evaluation process.

Impedance planimetry (EndoFLIP™) after magnetic sphincter augmentation (LINX®) compared to fundoplication.

INTRODUCTION: Functional luminal imaging probe (FLIP) use during laparoscopic fundoplication (LF) for gastroesophageal reflux disease is well described. However, there is a lack of data on FLIP measurements during magnetic sphincter augmentation (MSA). This study aims to report our institutional experience in performing FLIP during MSA and to compare these measurements to those obtained during Nissen and Toupet fundoplication. METHODS AND PROCEDURES: A retrospective review of a prospectively maintained quality database was performed. Patients who underwent MSA or LF and had FLIP measurements between April 2018 and June 2021 were included. FLIP measurements at the gastroesophageal junction (GEJ) were recorded without pneumoperitoneum at 40 mL balloon fill after hernia reduction, cruroplasty, and MSA or fundoplication. Reflux symptom index (RSI), GERD-HRQL, and dysphagia score were collected up to 2 years. Group comparisons were made using two-tailed Wilcoxon rank-sum and χ2 tests, with statistical significance of p < 0.05. RESULTS: Twenty-seven patients underwent MSA and 100 patients underwent LF (66% Toupet, 34% Nissen). Type III hiatal hernia was present in 3.7% of MSA patients versus over 50% for fundoplication patients. Minimum diameter, cross-sectional area, and distensibility index (DI) were lower after MSA device placement compared to Nissen or Toupet fundoplication (p < 0.05). Postoperative follow-up showed no differences in RSI, GERD-HRQL, and dysphagia score between MSA and Nissen fundoplication (p > 0.05). CONCLUSION: Intraoperative impedance planimetry provided objective information regarding the geometry of the GEJ during MSA. The ring of magnetic beads restores the anti-reflux barrier and transiently opens with food bolus and belching. The magnetic force of the beads may explain why the DI after MSA is lower yet postoperative quality of life is no different than Nissen fundoplication.

A modular simulation curriculum to teach endoscopic stenting to practicing surgeons: an "Into the fire" approach.

BACKGROUND: Flexible endoscopy is a valuable tool for the gastrointestinal (GI) surgeon, creating a need for effective and efficient training curricula in therapeutic endoscopic techniques for trainees and practicing providers. Here, we present a simulation-based modular curriculum using an "into the fire" approach with hands-on pre- and post-testing to teach endoscopic stenting to practicing surgeons. METHODS: Three advanced flexible endoscopy courses were taught by expert surgical endoscopists from 2018 to 2019. The stenting module involved using self-expandable metal stents to manage simulated esophageal and gastroduodenal strictures on a non-tissue GI model. Based on the educational theories of inquiry-based learning, the simulation curriculum was designed with a series of pre-tests, didactics, mentored hands-on instructions, and post-tests. Assessments included a confidence survey, knowledge-based written test, and evaluation form specific to the hands-on performance of endoscopic stenting. RESULTS: Twenty-eight practicing surgeons with varying endoscopic experiences participated in the course. Most of the participants (67.9%) had completed over 100 upper endoscopic procedures and 57.1% were certified in Fundamentals of Endoscopic Surgery. After completing the modular curriculum, participant confidence survey scores improved from 11.4 ± 4.2 to 20.7 ± 4.0 (p < 0.001). Knowledge-based written test scores also improved from 7.1 ± 1.2 to 8.4 ± 0.9 (p < 0.001). In terms of technical performance, overall hands-on performance scores improved from 21.3 ± 2.7 to 28.9 ± 1.2 (p < 0.001) with significant improvement in each individual component of the assessment (all p values < 0.01) and the greatest improvement seen in equipment handling (88%) and flow of procedure (54%). CONCLUSION: Our modular simulation curriculum using an "into the fire" approach to teach endoscopic stenting is effective in improving learner knowledge, confidence, and hands-on performance of endoscopic stenting. This approach to simulation is effective, efficient, and adaptable to teaching practicing surgeons with varying levels of experience.

Patient-reported bowel and bladder function is not adversely impacted by bariatric surgery.

INTRODUCTION: This study aims to assess the effect of bariatric surgery on patient-reported outcomes of bowel and bladder function. We hypothesized that bariatric surgery does not worsen bowel and bladder function. METHODS AND PROCEDURES: A retrospective review was conducted of a prospectively maintained surgical quality database. We included patients who underwent primary bariatric surgery at a single institution between 2012 and 2020, excluding revisional procedures. Patient-reported outcomes were assessed using Surgical Outcomes Measurement System (SOMS) bowel and bladder function questionnaires at time of pre-operative consult and routine post-operative follow-up visits through 2 years. Data were analyzed using a statistical mixed effects model. RESULTS: 573 patients (80.6% female) were identified with completed SOMS questionnaire data on bowel and bladder function. Of these, 370 (64.6%) underwent gastric bypass, 190 (33.2%) underwent sleeve gastrectomy, and 13 (2.3%) underwent either gastric banding or duodenal switch. Compared to pre-operative baseline scores, patients reported a transient worsening of bowel function at 2-weeks post-op (p = 0.009). However, by 3-months post-op, bowel function improved and was significantly better than baseline (p = 0.006); this improvement was sustained at every point through 2-year follow-up (p = 0.026). Bladder function scores improved immediately at 2-weeks post-op (p = 0.026) and showed sustained improvement through 1-year follow-up. On subgroup analysis, sleeve patients showed greater improvement in bowel function than bypass patients at 1-year (p = 0.031). Multivariable analysis showed significant improvement in bowel function associated with greater total body weight loss (TBWL) (p = 0.002). CONCLUSIONS: Bariatric surgery does not worsen patient-reported bowel or bladder function. In fact, there is overall improvement from pre-operative scores for both bowel and bladder function by 3-months post-op which is sustained through 2-year and 1-year follow-up, respectively. Most encouragingly, a greater TBWL is significantly associated with improved bowel function after bariatric surgery.

Impedance planimetry (EndoFLIP™) reveals changes in gastroesophageal junction compliance during fundoplication.

INTRODUCTION: Compliance is the ability of a hollow organ to dilate and increase volume with an increase in pressure, an accurate representation of food bolus transit through the gastroesophageal junction (GEJ). Impedance planimetry system can calculate compliance (change in volume over pressure) and distensibility (cross-sectional area over pressure) of the GEJ. We aim to describe the changes in compliance during anti-reflux surgery and hypothesize that compliance is a better predictor of patient outcomes than distensibility (DI). METHODS AND PROCEDURES: A review of a prospectively maintained quality database was performed. Patients with FLIP measurements during laparoscopic fundoplication between August 2018 and June 2021 were included. GEJ compliance and DI were measured after hernia reduction, cruroplasty, and fundoplication. Patient-reported outcomes were collected through standardized surveys up to 2 years after surgery. A scatter plot was used to identify a correlation between compliance and DI. Comparisons of measurements between time points were made using paired t-tests. Spearman's correlation coefficients (ρ), Wilcoxon rank-sum, and chi-square tests were used to evaluate associations between measurements and outcomes. RESULTS: One hundred and forty-four patients underwent laparoscopic fundoplication. Compliance is strongly associated with DI (r = 0.96), and a comparison of measurements showed similar trends at specific time points during the operation. After hernia reduction, compliance at the GEJ was 168 ± 74 mm3/mmHg, cruroplasty 79 ± 39 mm3/mmHg, and fundoplication 90 ± 33 mm3/mmHg (all comparisons p < 0.05). GEJ compliance of 80-92 mm3/mmHg after fundoplication was associated with the best patient-reported outcome scores. A compliance of ≤ 79 mm3/mmHg had the highest percentage of patients who reported dysphagia. CONCLUSIONS: Compliance and DI are strongly associated displaying the same directional change during anti-reflux surgery. GEJ compliance of 80-92 mm3/mmHg revealed the best patient-reported outcome scores, and avoiding a compliance ≤ 79 mm3/mmHg may prevent postoperative dysphagia. Therefore, GEJ compliance is an underutilized FLIP measurement warranting further investigation.

Long-term retention after structured curriculum on attainment of critical view of safety during laparoscopic cholecystectomy for surgeons.

BACKGROUND: Obtaining a clear Critical View of Safety helps prevent bile duct injuries during laparoscopic cholecystectomy, which can be improved with a structured Safe Critical View of Safety curriculum. We aimed to determine whether the improvement in obtaining Critical View of Safety postcurriculum is retained long-term. METHODS: A safe Critical View of Safety curriculum was previously implemented for all surgeons who perform laparoscopic cholecystectomy at a regional health system. Recordings of laparoscopic cholecystectomy cases were collected 1 year after completion of the curriculum, deidentified and randomly ordered, and then graded by 2 blinded expert surgeons using a 6-point Critical View of Safety assessment tool. RESULTS: A total of 12 surgeons with average experience of 17.9 ± 6.3 years in practice participated in the study. The majority (83%) had performed >700 laparoscopic cholecystectomies, and 4 surgeons (33%) reported 2 or more bile duct injuries in their career. Controlling for gallbladder pathology, Critical View of Safety scores improved from 1.7 ± 0.4 to 4.0 ± 0.4 (P < .001) immediately after completion of the curriculum. However, there was a small decrease in Critical View of Safety score after 1 year (3.2 ± 0.3 from 4.0 ± 0.4, P = .055), while still significantly higher compared to precurriculum (3.2 ± 0.3 vs 1.7 ± 0.4, P < .001). Acute care surgeons had lower Critical View of Safety retention scores compared to general surgeons (1.8 ± 0.5 vs 3.3 ± 0.4, P = .01) and minimally invasive surgeons (1.8 ± 0.5 vs 3.8 ± 0.5, P < .01). CONCLUSION: A structured curriculum helped improve practicing surgeons' attainment of obtaining the Critical View of Safety during laparoscopic cholecystectomy. However, this improvement decreased after 1 year, suggesting some decay in knowledge retention over time. Therefore, continued educational interventions on Critical View of Safety and safe laparoscopic cholecystectomy may be needed to enhance long-term retention.

Impedance Planimetry (Endoflip™) Shows That Length of Narrowing After Fundoplication Does Not Impact Dysphagia.

INTRODUCTION: A short floppy fundoplication has been the surgical dogma to prevent dysphagia and gas-bloat after laparoscopic fundoplication while adequately addressing gastroesophageal reflux disease. The literature on the ideal length of narrowing (LON) of the gastroesophageal junction after fundoplication is sparse. The functional luminal imaging probe (FLIP) can be used during anti-reflux surgery to produce a visual representation of the LON. We hypothesize that a longer LON provides relief of GERD symptoms, however worse dysphagia and gas-bloat. METHODS AND PROCEDURES: Prospectively collected data was analyzed. Patients with FLIP measurements during laparoscopic fundoplication between August 2018 and December 2020 were included. FLIP measurements at the gastroesophageal junction were recorded without pneumoperitoneum at 40-mL balloon fill after fundoplication. Reflux Symptom Index (RSI), Gastroesophageal Reflux Disease-Health Related Quality of Life Questionnaire (GERD-HRQL), gas-bloat score, and Dysphagia Score were collected. Comparisons were made using Spearman correlation coefficients (r) and two-tailed Wilcoxon rank-sum tests, with statistical significance set at p < 0.05. RESULTS: One hundred and eleven patients underwent laparoscopic fundoplication (26% Nissen, 74% Toupet) and had FLIP measurements. Mean LON in this cohort was 2.7 ± 0.8 cm and mean DI was 3.5 ± 1.3 mm2/mmHg. LON is inversely associated with RSI (r = - 0.29, p = 0.04) and gas-bloat (r = - 0.30, p = 0.04). There was no association with Dysphagia Score. Patients with a LON of 2.5-4.5 cm and DI of 2.5-3.6 mm2/mmHg after fundoplication reported lower RSI (p = 0.03) and GERD-HRQL (p = 0.04) compared to patients outside of these ranges. There were no significant differences in patient-reported dysphagia or gas-bloat scores at 1 year between these groups. CONCLUSIONS: Impedance planimetry provides objective real-time measurements and images during anti-reflux surgery, which allows surgeons to measure the length of narrowing after fundoplication. A LON of 2.5-4.5 cm and DI of 2.5-3.6 mm2/mmHg after fundoplication led to better postoperative quality of life at 1 year without an increase in postoperative dysphagia or gas-bloat.

Crural closure, not fundoplication, results in a significant decrease in lower esophageal sphincter distensibility.

INTRODUCTION: The esophagogastric junction (EGJ) is a complex anti-reflux barrier whose integrity relies on both the intrinsic lower esophageal sphincter (LES) and extrinsic crural diaphragm. During hiatal hernia repair, it is unclear whether the crural closure or the fundoplication is more important to restore the anti-reflux barrier. The objective of this study is to analyze changes in LES minimum diameter (Dmin) and distensibility index (DI) using the endoluminal functional lumen imaging probe (FLIP) during hiatal hernia repair. METHODS: Following implementation of a standardized operative FLIP protocol, all data were collected prospectively and entered into a quality database. This data were reviewed retrospectively for all patients undergoing hiatal hernia repair. FLIP measurements were collected prior to hernia dissection, after hernia reduction, after cruroplasty, and after fundoplication. Additionally, subjective assessment of the tightness of crural closure was rated by the primary surgeon on a scale of 1 to 5, 1 being the loosest and 5 being the tightest. RESULTS: Between August 2018 and February 2020, 97 hiatal hernia repairs were performed by a single surgeon. FLIP measurements collected using a 40-mL volume fill without pneumoperitoneum demonstrated a significant decrease in LES Dmin (13.84 ± 2.59 to 10.27 ± 2.09) and DI (6.81 ± 3.03 to 2.85 ± 1.23 mm2/mmHg) after crural closure (both p < 0.0001). Following fundoplication, there was a small, but also statistically significant, increase in both Dmin and DI (both p < 0.0001). Additionally, subjective assessment of crural tightness after cruroplasty correlated well with DI (r = - 0.466, p < 0.001) and all patients with a crural tightness rating ≥ 4.5 (N = 13) had a DI < 2.0 mm2/mmHg. CONCLUSION: Cruroplasty results in a significant decrease in LES distensibility and may be more important than fundoplication in restoring EGJ competency. Additionally, subjective estimation of crural tightness correlates well with objective FLIP evaluation, suggesting surgeon assessment of cruroplasty is reliable.

Teaching EndoFLIP Impedance Planimetry to Practicing Endoscopists: An "Into the Fire" Approach to Simulation.

Background. There are growing interests from practicing endoscopists to implement the functional lumen imaging probe (FLIP) impedance planimetry system. We present a simulation-based curriculum using an "into the fire" approach with hands-on pre- and post-tests to teach the use of this technology. Methods. The curriculum consists of a series of pre-tests, didactic content, mentored hands-on instructions, and post-tests. Pre- and post-testing included a knowledge-based written test, a confidence survey, and an assessment form specific to the hands-on performance of FLIP. Result. Twenty-two practicing physicians completed the curriculum. After course completion, participants had improved knowledge-based written test scores from 6.8±1.7 to 8.9±0.9 (P<0.001), confidence scores from 10.0±5.9 to 22.1±2.6 (P<0.001), and hands-on performance score from 11.4±3.4 to 23.1±2.0 (P<0.001) with significant improvement in all components of the hands-on skills. Conclusion. Our simulation curriculum is effective in improving confidence, knowledge, and technical proficiency when teaching the use of FLIP to practicing physicians.

Zenker's peroral endoscopic myotomy, or flexible or rigid septotomy for Zenker's diverticulum: a multicenter retrospective comparison.

BACKGROUND: Treatment of Zenker's diverticulum has evolved from open surgery to endoscopic techniques, including flexible and rigid endoscopic septotomy, and more recently, peroral endoscopic myotomy (Z-POEM). This study compared the effectiveness of flexible and rigid endoscopic septotomy with that of Z-POEM. METHODS: Consecutive patients who underwent endoscopic septotomy (flexible/rigid) or Z-POEM for Zenker's diverticulum between 1/2016 and 9/2019 were included. Primary outcomes were clinical success (decrease in Dakkak and Bennett dysphagia score to ≤ 1), clinical failure, and clinical recurrence. Secondary outcomes included technical success and rate/severity of adverse events. RESULTS: 245 patients (110 females, mean age 72.63 years, standard deviation [SD] 12.37 years) from 12 centers were included. Z-POEM was the most common management modality (n = 119), followed by flexible (n = 86) and rigid (n = 40) endoscopic septotomy. Clinical success was 92.7 % for Z-POEM, 89.2 % for rigid septotomy, and 86.7 % for flexible septotomy (P = 0.26). Symptoms recurred in 24 patients (15 Z-POEM during a mean follow-up of 282.04 [SD 300.48] days, 6 flexible, 3 rigid [P = 0.47]). Adverse events occurred in 30.0 % rigid septotomy patients, 16.8 % Z-POEM patients, and 2.3 % flexible septotomy patients (P < 0.05). CONCLUSIONS: There was no difference in outcomes between the three treatment approaches for symptomatic Zenker's diverticulum. Rigid endoscopic septotomy was associated with the highest rate of complications, while flexible endoscopic septotomy appeared to be the safest. Recurrence following Z-POEM was similar to flexible and rigid endoscopic septotomy. Prospective studies with long-term follow-up are required.

Significant changes in impedance planimetry (EndoFLIP™) measurements after peroral pyloromyotomy for delayed gastric emptying.

BACKGROUND: The endoluminal functional lumen imaging probe (FLIP) can be used to obtain real-time measurements of the diameter (Dmin), cross-sectional area (CSA), and distensibility of the pylorus before and after peroral pyloromyotomy (POP), an emerging endoscopic treatment for delayed gastric emptying. Our study aims to report our single-center experience in performing POP with FLIP measurements before and after pyloromyotomy. METHODS: A retrospective review of a prospectively maintained gastroesophageal database was performed. Demographic and perioperative data, including intraoperative FLIP measurements of the pylorus before and after POP, were analyzed. Measurements were compared using paired t tests. RESULTS: Thirty-four patients underwent POP between February 2017 and July 2020. Twenty-three (67.7%) patients were male and the average age was 59 years. The etiology of delayed gastric emptying was post-vagotomy in 22 patients, idiopathic gastroparesis in 7 patients, and diabetic gastroparesis in 5 patients. There were no significant differences in pre-myotomy or post-myotomy FLIP measurements when comparing the post-vagotomy versus the gastroparesis groups. There were significant increases in Dmin, CSA, and distensibility index when comparing pre-myotomy and post-myotomy readings for all patients (all p < 0.001). At follow-up, 64.7% of patients reported resolution of all symptoms. CONCLUSION: POP is an effective intervention in patients with delayed gastric emptying. Significant changes in FLIP measurements before and after POP suggest that FLIP may be a useful adjunct in guiding the management of delayed gastric emptying.

Impedance planimetry (EndoFLIP) measurements persist long term after anti-reflux surgery.

PURPOSE: The functional lumen imaging probe provides objective measurements of the gastroesophageal junction during laparoscopic anti-reflux surgery. There is a lack of data on how functional lumen imaging probe measurements change at follow-up. We aim to describe our institutional experience in performing functional lumen imaging probe during postoperative endoscopy after laparoscopic anti-reflux surgery. METHODS: A prospectively maintained database was queried. Patients who had postoperative endoscopic functional lumen imaging probe measurements between March 2018 and June 2021 were assessed at different time points from their index laparoscopic anti-reflux surgery using paired t test. Standardized quality of life questionnaires were collected for up to 2 years. Group comparisons were made using the Wilcoxon rank-sum test. RESULTS: Fifty-eight patients who underwent laparoscopic anti-reflux surgery (magnetic sphincter augmentation or fundoplication) had postoperative functional lumen imaging probe. Thirty-two intraoperative functional lumen imaging probe values were compared with their postoperative functional lumen imaging probe. Fundoplication values did not differ. Postoperative functional lumen imaging probe distensibility index for magnetic sphincter augmentation patients was decreased (P = .04). Functional lumen imaging probe measurements for all postoperative endoscopies showed that magnetic sphincter augmentation had the lowest distensibility index (P < .01). Dysphagia as a reason for endoscopy had a decrease in distensibility index (P = .03). CONCLUSION: Functional lumen imaging probe measurements after fundoplication persist at long-term follow up while patients may have a tighter gastroesophageal junction after magnetic sphincter augmentation. Functional lumen imaging probe has the potential to assess the success or failure after laparoscopic anti-reflux surgery and optimize patient outcomes.