High-volume Centers Research Articles

778. ROBOTIC-ASSISTED EPIPHRENIC DIVERTICULECTOMY: 9 YEAR EXPERIENCE OF A TERTIARY CENTER

Abstract Background Epiphrenic esophageal diverticula are rare and often associated with esophageal motor disorders. Surgery is reserved for larger diverticula with symptoms that significantly impair quality of life. When possible, a transhiatal approach can reduce pulmonary complications by preserving pleural integrity; more proximal diverticular openings require a combined transthoracic and abdominal approach to achieve complete excision. Robotic surgery assists in precise dissection and preservation of delicate mediastinal structures. Currently, few reports are available on larger patient cohorts of robotic diverticulectomy. We describe all consecutive cases of robotic-assisted epiphrenic diverticulectomy performed at a high-volume tertiary center, since robotic surgery became available in 2015. Methods A retrospective chart review was conducted and, for all consecutive diverticulectomy cases, surgical techniques, patient characteristics and short and long-term outcomes were recorded. All patients underwent preoperative EGDS and esophagogram. Diverticulectomy was always accompanied by esophagogastric Heller myotomy (>7 cm) and Dor fundoplication with the Xi DaVinci system was performed. One to two SIGNA linear stapler firings were used for diverticular resection. Symptoms, demographic data, and short and long-term surgical outcomes were recorded, including morbidity and mortality and post-operative symptoms. Results Four cases required both an abdominal and intrathoracic approach, none was converted. Intraoperative complications included one occurrence of splenic bleeding controlled by hemostatic. Intraoperative blood loss was negligible. In two cases an esophageal leiomyoma was found incidentally and excised. The only postoperative complication was trocar-related abdominal wall bleeding that led to reintervention for cauterization; mortality was zero. All patients underwent a post-op esophagogram, negative for leaks or strictures, and resumed soft feeding within 7 days. All reported substantial symptom relief at six months. At one year, one patient reported reflux, and two reported dysphagia recurrence without evident structures or recurrences. Conclusion Robotic-assisted diverticulectomy is safe and effective for epiphrenic diverticula. The abdominal approach allows for a thorough esophageal myotomy associated with a For antireflux procedure to reduce recurrences of the disease and long-term dysphagia. In some cases a transthoracic approach is also needed, when employed by experienced upper GI surgeons it doesn't significantly affect surgical outcomes. Quality of life improves after surgery, although symptomatic reflux might occur. Further prospective or experimental studies are needed to evaluate short and long-term outcomes of the robotic approach compared to other surgical approaches.

252. RIGHT GASTROEPIPLOIC ARTERY LENGTH DETERMINED ANASTOMOTIC LEAKRIGHT GASTROEPIPLOIC ARTERY LENGTH DETERMINED ANASTOMOTIC LEAKAGE AFTER MINIMALLY INVASIVE ESOPHAGECTOMY FOR ESOPHAGEAL CANCER-A PROSPECTIVE COHORT STUDY

Abstract Background This prospective cohort study, conducted at a high-volume esophageal cancer center from July 2019 to July 2022, aimed to investigate the link between the right gastroepiploic artery (RGEA) length and anastomotic leakage (AL) rates following minimally invasive esophagectomy (MIE). Real-world data on stomach blood supply in the Chinese population were examined. Materials and methods A total of 516 cases were enrolled, categorized into two groups based on the Youden index-determined optimal cut-off value for the relative length of RGEA (length of RGEA/length of gastric conduit, 64.69%) through ROC analysis: Group SR (short RGEA) and Group LR (long RGEA). The primary observation parameter was the relationship between AL incidence and the ratio of direct blood supply from RGEA. Secondary parameters included the mean length of the right gastroepiploic artery, greater curvature, and the connection type between right and left gastroepiploic vessels. Patient data were prospectively recorded in electronic case report forms. Results The study revealed median lengths of 43.60 cm for greater curvature, 43.16 cm for the gastric conduit, and 26.75 cm for RGEA. AL, the most common postoperative complication, showed a significant difference between groups (16.88% vs. 8.84%, p = 0.01). Multivariable binary logistic regression identified Group SR and LR (Odds ratio: 2.651, 95% CI: 1.124–6.250, p = 0.03) and Neoadjuvant therapy (Odds ratio: 2.479, 95% CI: 1.374–4.473, p = 0.00) as independent predictors of AL. Conclusions The study emphasizes the crucial role of RGEA length in determining AL incidence in MIE for esophageal cancer. Preserving RGEA and fostering capillary arches between RGEA and LGEA are recommended strategies to mitigate AL risk.

Long-term impact of scheduled regular endoscopic interventions for patients with primary sclerosing cholangitis.

Primary sclerosing cholangitis (PSC) is associated with biliary obstructions that can require endoscopic retrograde cholangiopancreatography (ERCP). While the beneficial effects of ERCP are well documented, follow-up interventional strategies are less defined, and their long-term impact is debated. We evaluated the outcome of a scheduled program of ERCP-guided interventions that have been developed and implemented at our tertiary liver center for more than 20 years. Within our center, follow-up ERCPs were performed at regular intervals to treat previously detected morphological stenosis independent of clinical symptoms. We calculated the transplant-free survival (TFS) of patients who were enrolled in the scheduled ERCP program and compared it to patients who received follow-up ERCPs only on clinical demand. Moreover, we documented the occurrence of hepatic decompensation, recurrent cholangitis episodes, hepatobiliary malignancies, and endoscopy-related adverse events. In our retrospective study, we included 201 patients with PSC who all received an ERCP. In all, 133 patients received scheduled follow-up ERCPs and 68 received follow-up ERCPs only on demand. The rates of TFS since initial diagnosis (median TFS: 17 vs. 27 y; P = 0.020) and initial presentation (median TFS: 16 vs. 11 y; P = 0.002) were higher in patients receiving scheduled versus on-demand ERCP. Subgroup analysis revealed that progression in cholangiographic findings between the first and second ERCP was associated with a poorer outcome compared to patients without progression (17 y vs. undefined; P = 0.021). In conclusion, we report the outcome data of a scheduled follow-up ERCP program for patients with PSC in an experienced high-volume endoscopy center. Our data suggest the initiation of multicenter randomized controlled prospective trials to explore the full potential of regular endoscopic follow-up treatment as a strategy to prevent disease progression in patients with PSC.

Postoperative Delirium Screening Characteristics in Pediatric Intestinal, Liver, and Renal Transplant Recipients: Single-Center Retrospective Cohort Study.

To describe and compare the results of delirium screening in the immediate post-transplant PICU admission for pediatric intestinal, liver, and renal transplant recipients. We also examined associations with known and suspected risk factors for pediatric delirium (PD). Retrospective analysis of a single-center cohort, 2016-2022. Twenty-four-bed PICU in a high-volume transplant center. All intestinal, liver, and renal transplant recipients under 23 years old admitted between July 2016 and August 2022. We identified 211 pediatric transplant recipients: intestinal ( n = 36), liver ( n = 78), and renal ( n = 97). Results of the Cornell Assessment for PD during the immediate post-transplant PICU admission were reviewed and patients were categorized into screen positive, screen negative, and unscreened. Corresponding data on known and suspected risk factors for PD were also collected. Data on delirium subtypes were not collected. Screens were available for 156 of 211 patients (74%) who were included in the final analysis. The prevalence of a positive screen by transplant category was: intestine 80% (24/30), liver 75% (47/63), and renal 14% (9/63). A positive screen was associated with younger age, greater duration of mechanical ventilation, and greater PICU length of stay (LOS) in bivariate analysis. In multivariable analysis, age and PICU LOS remained strongly correlated with a positive screen ( p < 0.05). Deep sedation and agitation as categorized by the State Behavioral Scale was associated with a positive screen, as was significant iatrogenic withdrawal symptoms ( p < 0.05). Most patients screened positive by post-transplant days 2 and 3 (58/80 [72%] and 64/80 [80%], respectively). In our 2016 to 2022 experience, we found a high prevalence of positive PD screens in pediatric intestinal and liver transplant recipients in the immediate post-transplant PICU admission. A positive screen was associated with younger age and greater PICU LOS.

Outcomes of transcatheter aortic valve implantation for native aortic valve regurgitation.

Large datasets of transcatheter aortic valve implantation (TAVI) for pure aortic valve regurgitation (PAVR) are scarce. We aimed to report procedural safety and long-term clinical events (CE) in a contemporary cohort of PAVR patients treated with new-generation devices (NGD). Patients with grade III/IV PAVR enrolled in the FRANCE-TAVI Registry were selected. The primary safety endpoint was technical success (TS) according to Valve Academic Research Consortium 3 criteria. The co-primary endpoint was defined as a composite of mortality, heart failure hospitalisation and valve reintervention at last follow-up. From 2015 to 2021, 227 individuals (64.3% males, median age 81.0 [interquartile range {IQR} 73.5-85.0] years, with EuroSCORE II 6.0% [IQR 4.0-10.9]) from 41 centres underwent TAVI with NGD, using either self-expanding (55.1%) or balloon-expandable valves (44.9%; p=0.50). TS was 85.5%, with a non-significant trend towards increased TS in high-volume activity centres. A second valve implantation (SVI) was needed in 8.8% of patients, independent of valve type (p=0.82). Device size was ≥29 mm in 73.0% of patients, post-procedure grade ≥III residual aortic regurgitation was rare (1.2%), and the permanent pacemaker implantation (PPI) rate was 36.0%. At 30 days, the incidences of mortality and reintervention were 8.4% and 3.5%, respectively. The co-primary endpoint reached 41.6% (IQR 34.4-49.6) at 1 year, increased up to 61.8% (IQR 52.4-71.2) at 4 years, and was independently predicted by TS, with a hazard ratio of 0.45 (95% confidence interval: 0.27-0.76); p=0.003. TAVI with NGD in PAVR patients is efficient and reasonably safe. Preventing the need for an SVI embodies the major technical challenge. Larger implanted valves may have limited this complication, outweighing the increased risk of PPI. Despite successful TAVI, PAVR patients experience frequent CE at long-term follow-up.

PJY07 The PSMA PET staging conundrum: A survey of UK high volume centres and their use of PSMA PET before robotic prostatectomy

PJY07 The PSMA PET staging conundrum: A survey of UK high volume centres and their use of PSMA PET before robotic prostatectomy

528. IMPACT OF SARCOPENIA AND MYOSTEATOSIS ON THE SURGICAL OUTCOME OF PATIENTS WITH ESOPHAGEAL CANCER

Abstract Background Alterations in muscle mass, sarcopenia and myosteatosis might negatively affect the surgical outcome of patients with cancer. Body composition correlation with biochemical markers and impact on surgical outcome in esophageal cancers is yet to be fully determined. Study design Patients with esophageal and esophageal-gastric junction cancer undergoing resection with curative intent were enrolled in a prospective clinical trial from to 2019 to 2023. Patients were assessed at presentation for anthropometric measures, past medical history and biohumoral markers. Contrast-enhanced CT-scans were used to analyze body composition and to detect low lumbar skeletal muscle index (SMI) and low mean muscle attenuation. We investigated the association between the presence of sarcopenia and/or myosteatosis and malnutrition or systemic inflammatory state. Results We enrolled 130 esophagogastric cancer patients who underwent Ivor-Lewis esophagectomy. Postoperative morbidity was not significantly higher in the sarcopenic group compared to non-sarcopenic patients (p=0.35). Myosteatosis and albumin level weren’t associated with post-operative morbidity (p=0.11). No differences in overall survival were found in patients with myosteatosis or sarcopenia compared to subjects with normal body composition (p=0.12 and p=0.16). Conclusion Our preliminary data shows no significant correlations between sarcopenia and myosteatosis and postoperative outcome and survival following esophagectomy for esophageal cancer. These findings from an high volume center suggest that factors other than these body composition parameters may play a more significant role in determining postoperative outcomes in patients undergoing esophagectomy. Further research is warranted to elucidate additional prognostic indicators and optimize patients care in this population.

554. SHORT TERM OUTCOMES OF ESOPHAGECTOMY FROM LOW VOLUME CANCER CENTRE IN INDIA

Abstract This study evaluates short term outcomes of esophagectomy at a low volume cancer hospital in Visakhapatnam, India. Fifteen patients who underwent esophagectomy from 2020 to 2023 were analysed. The most common histology was squamous cell carcinoma. The mean age was 55 years and the majority were male. The common approaches used were open trans hiatal and transthoracic esophagectomy. The mean operative time was 9.5 hours and the mean hospital stay was 15.92 days. There were no perioperative deaths but complications included pulmonary issues, vocal cord paralysis, anastomotic leaks, chyle leaks and wound infections. Higher volume centres tend to have better outcomes after esophagectomy. However, factors other than volume like patient selection, ERAS (Enhanced Recovery After Surgery) protocols, specialized critical care and trained multidisciplinary teams also impact outcomes. At our centre, though a low volume hospital, proper patient selection, prehabilitation and a collaborative team approach helped achieve acceptable results. We recommend developing consensus on defining low and high-volume centres for esophagectomy in the Indian context, based on disease burden, resources and constraints. Overall, there is a lack of Indian data comparing outcomes between low and high-volume centres for esophagectomy.

556. PREDICTORS OF EARLY RECURRENCE AFTER OESOPHAGECTOMY AND NEOADJUVANT FLOT

Abstract Background FLOT, a novel type of perioperative chemotherapy, has led to improved survival after surgery for oesophageal adenocarcinoma. Yet, rates of cancer recurrence remain high. There is limited research on predictors for early recurrence (ER) in patients receiving FLOT. The aim of this study was to investigate ER and survival rates and identify risk factors of ER. Methods Patients who underwent neoadjuvant FLOT and oesophagectomy for oesophageal and oesophagogastric junction adenocarcinomas at a single high-volume centre between August 2018 and January 2023 were evaluated for ER, defined as disease present within one year of surgery. Multivariable logistic regression was conducted to identify risk factors for ER. Patients who died in-hospital or within 90 days of surgery and those with positive longitudinal margin were excluded. Results 145 patients were included. 139 (95.9%) and 63 (43.4%) patients fully completed neoadjuvant and adjuvant FLOT. 44 patients (30.3%) developed recurrence and 22 patients (15.2%) had ER in the follow up period. Distant, local or mixed type of recurrence was found in 32, 6 and 6 patients respectively. The estimated recurrence free survival and overall survival at one, two and three years were 81.4%, 66.9%, 52.0% and 89.0%, 73.7%, 65.5% respectively. The estimated median survival after recurrence was 4.9 months. In multivariable analysis ypN3 status was identified to be an independent predictor of ER (OR 13.769, 95%CI 1.358-139.573, p=0.026). Conclusions This study confirms that ER after neoadjuvant FLOT is common. Patients with a high pathological nodal stage are particularly at risk. It is possible that some patients with ER might have undetected metastases prior to surgery and some do not respond well to neoadjuvant treatment. Identifying chemotherapy non-responders is an important area for future research. These results might be beneficial for prognostication and tailoring follow up care, such as regular surveillance imaging, treatment, and frequency of reviews.

Predictive factors for postoperative ileus after elective right hemicolectomy performed on over 80% Enhanced Recovery After Surgery-adherent patients: a retrospective cohort study.

Laparoscopic right hemicolectomy is the standard surgical approach for treatment of right-sided colonic neoplasms. Although performed within a strict Enhanced Recovery After Surgery (ERAS) program, patients still develop postoperative ileus. The aim of this study was to describe the factors responsible for postoperative ileus after right hemicolectomy in a patient population with over 80% ERAS adherence. In this retrospective study, we analyzed 499 consecutive patients undergoing elective right-sided colectomy for neoplastic disease in a single high-volume center. All patients followed an updated ERAS program. The overall median ERAS adherence was 80%. Patients with ≥ 80% adherence (n = 271) were included in further analysis. Their median ERAS adherence was 88.9% (interquartile range, 80-90; range, 80-100). Twenty-four of 271 patients (8.9%) developed postoperative ileus. A univariate regression analysis revealed carcinoma situated in the transverse colon, duration of operation over 200 minutes, and opiate consumption over 10 mg on the second postoperative day (POD) to be associated with a significantly higher risk of postoperative ileus. Multivariate regression analysis revealed that duration of surgery over 200 minutes (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.0-5.8; P = 0.045) and opiate consumption over 10 mg on POD 2 (OR, 4.8; 95% CI, 1.6-14.3; P = 0.005) independently predict a higher risk for postoperative ileus. The median length of hospital stay was significantly longer in patients with postoperative ileus (8 days vs. 3 days, P < 0.001). None of the 271 patients died during a 30-day follow-up. Long duration of surgery, even minor postoperative opiate use, predict a higher risk for postoperative ileus in strictly ERAS-adherent patients undergoing laparoscopic right hemicolectomy.

632. CAN CARDIOPULMONARY EXERCISE TESTING PREDICT NEOADJUVANT CHEMOTHERAPY TOXICITY IN OESOPHAGEAL ADENOCARCINOMA PATIENTS?

Abstract Background Cardiopulmonary exercise testing (CPET) is a method of assessing cardiopulmonary fitness. In the context of surgery, it is used to risk-stratify patients, allowing targeted prehabilitation to optimise comorbidities and fitness prior to surgery, and triage patients to the appropriate level of care after the operation. Various CPET-derived variables have been shown to be associated with short- and long-term outcomes after various surgery. In patients post-oesophagectomy, these variables are predictive of long-term survival. This study aimed to assess the use of this tool to predict neoadjuvant chemotherapy (NAC) related complications in patients receiving neoadjuvant FLOT prior to oesophagectomy. Methods All patients who underwent routine CPET during the staging process prior to NAC with FLOT and oesophagectomy in a single high-volume centre between September 2018 and January 2023 were included. Data were extracted from the unit’s contemporaneously maintained database. The Mann-Whitney U test was used to compare CPET variables in patients who completed NAC with FLOT fully versus those who did not finish NAC with FLOT due to acute chemotherapy toxicities. Results There were 129 patients who received neoadjuvant FLOT and had routine CPET performed during the defined study period. Six of those patients (4.7%) did not complete neoadjuvant chemotherapy due to acute chemotherapy toxicities but progressed to surgery. The median anaerobic threshold, VO2 peak, and VE/VCO2 among those who completed NAC were 14.2 ml/kg/min, 20.3 ml/kg/min, and 28, respectively, compared to 13.4 ml/kg/min, 19.7 ml/kg/min, and 31 in those who did not complete NAC (p=0.595, p=0.695, and p=0.160, respectively). Conclusion Although patients who received all four cycles of NAC with FLOT prior to oesophagectomy demonstrated CPET values indicating better base-line fitness than those who had to discontinue NAC due to acute chemotherapy toxicity, these differences did not reach the level of statistical significance. This study, therefore, did not demonstrate any predictive value of CPET in assessing the risk of incomplete NAC treatment prior to oesophagectomy.

HoLEP Learning Curve-Resident Perspective: Survey of Senior Residents from High-Volume Tertiary Center.

Objective: We aim to report the learning curve and experience performing holmium laser enucleation of the prostate (HoLEP) from a resident standpoint trained at a tertiary high-volume center. Methods: An electronic survey was distributed to 10 surveyees that included recently graduated chief residents trained at Indiana University in the past 3 years i.e., between 2020 and 2022 with a 100% response rate. The questionnaire focused on HoLEP training experience based on a recently established mentorship curriculum in training the residents through each individual step of the surgery. Results: The average learning curve for performing HoLEP was reported to be greater than 25 cases with 50% of the residents reporting >50 cases to master the technique. The surgical difficulty of steps of the HoLEP were rated on a subjective scale of 1-5: 1 = very easy, 2 = easy, 3 = neutral, 4 = hard, and 5 = very hard. The common challenging steps in decreasing the order of difficulty as reported are performing apical enucleation, joining anterior and posterior planes, and dividing anterior commissure with a mean rating of 3.5, 3.1, and 3.1, respectively. The most difficult aspect of the surgery to master was performing apical dissection (60%). Comparing operative parameters for HoLEP with transurethral resection of the prostate in aspects of resection volume and times, 70% of candidates reported it better for HoLEP whereas 20% had similar times for both procedures. A total of 90% of the residents felt confident to offer HoLEP as part of their practice without the need for any further training. Regarding the initial challenge of including HoLEP surgery in practice, the majority (60%) reported difficulty with equipment set up in their practice while 20% reported difficulty maintaining efficient operating room (OR) times and turnover. Conclusion: We believe HoLEP can be performed immediately after residency training and incorporated into practice with high volume, repeated exposure to HoLEP surgery throughout residency based on study results. The average learning curve reported for performing HoLEP was greater than 25 cases.

Incisional hernia after major pancreatic resection: long term risk assessment from two distinct sources – A large multi-institutional network and a single high-volume center

BackgroundPost-operative incisional hernia (IH) is a common complication following abdominal surgery. Data regarding IH after major pancreatic surgery are limited. We aim to evaluate the long-term risk of IH following major pancreatic resection. MethodsA dual-approach study: a large multi-institutional research network (RN) was investigated for IH incidence and risk factors in propensity-score matched survivors after pancreaticoduodenectomy (PD) and distal pancreatectomy (DP), was complemented by a patient-reported questionnaire. ResultsRN analysis identified 22,113 patients that underwent pancreatic surgery. 11.0% of PD patients and 8.6% of DP patients developed IH (P < 0.0001). IH rates were higher with open surgery compared with minimally invasive approaches in PD (OR = 1.56, P = 0.03) and DP (OR = 1.94, P = 0.003). BMI>35 was found to correlate with increased IH rates for PD and DP (OR = 1.87, and OR = 1.86, respectively, P < 0.0001 each), as did postoperative intraabdominal infections (P < 0.0001). Patient-based survey of 104 patients, revealed that 16 patients (15%) reported post-operative IH during the follow-up period. BMI≥30, SSI and intra-abdominal abscesses were associated with increased IH risk (P < 0.05). ConclusionImproved survival after pancreatic resection has led to an increased prevalence of long-term surgical sequela. In this study, we demonstrate significant rates of IH among long-term survivors and assess potential risk factors.

811. POOLED 1-YEAR SAFETY AND QUALITY-OF-LIFE DATA AFTER REFLUXSTOP SURGERY AT TWO LARGE HOSPITALS IN SWITZERLAND: A RETROSPECTIVE CHART ANALYSIS

Abstract Background The standards of care in reflux disease management are proton pump inhibitor (PPI) therapy and conventional antireflux surgery, however, both options carry the caveats of medication irresponsiveness and troublesome postoperative sequelae, respectively. More specifically, PPIs respond inadequately in up to 40% of cases and Nissen fundoplication is associated with postoperative dysphagia in a significant proportion of patients. RefluxStop is an innovative technology that was adopted at our two respective institutions following promising safety and effectiveness data from its CE mark trial. We present the pooled safety and quality-of-life data of our 1-year experience with RefluxStop surgery. Methods Between September 2018 and August 2023, RefluxStop surgery was performed on 121 patients as part of routine clinical care at two hospitals, both of which are high-volume centers for antireflux surgery. The procedure involves crural repair with hiatal hernia reduction, reconstruction of the flap valve and angle of His, narrow esophagogastric (90-110°) plication, and device implantation in an external pouch on the gastric fundus (Figure 1). A retrospective chart analysis was conducted to document perioperative adverse events (AEs) and quality-of-life improvements via Gastroesophageal Reflux Disease Health-Related Quality of Life (GERD-HRQL) score. Higher GERD-HRQL scores are indicative of more severe disease. Results Baseline patient characteristics included mean age 54.7 years, female sex (52.9%), body mass index 27.2±4.1 kg/m2, large hiatal hernia &amp;gt;3 cm (46.3%) of median (IQR) size 3 (2-5) cm, abnormal esophageal motility (60.3%), and Barrett’s esophagus (27.3%). At 1-year follow-up, patients experienced a median (IQR) reduction of 90.5% (81.4-100%) in total GERD-HRQL score. Intraoperative AEs included conversion to laparotomy for adhesiolysis with bleeding (n=1), bleeding short gastric arteries leading to return to the operating room the next day (n=1), and esophageal perforation repaired intraoperatively (n=1). Postoperative AEs are summarized in Table 1. Conclusion The results of this pooled retrospective chart analysis support the promising early data of the RefluxStop CE mark trial. Few and predictable AEs occurred during the study period while significant improvements in quality of life were observed, as evidenced by 90.5% (81.4-100%) reductions in GERD-HRQL score. Notably, this pooled cohort of patients was comprised of substantial proportions of difficult-to-treat patients (i.e., abnormal esophageal motility in 60.3%, large hiatal hernia &amp;gt;3 cm in 46.3%), providing evidence for wider implementation of RefluxStop surgery in real-world settings. Additional evaluation is required to further delineate the role of this promising innovative antireflux surgery.

Defining the optimal annual institutional case volume for minimally invasive repair of pectus excavatum through a systematic review of literature and meta-analysis of outcomes.

The Nuss procedure is the accepted standard approach to correct pectus excavatum. Still, is associated with potential major complications that are in part believed to be preventable as they might be the consequence of institutional case-volume differences. The objective is to evaluate the presence of a volume-outcome relation for the Nuss procedure and determine the optimal annual institutional case-volume threshold, defining high-volume centers. A systematic literature search was performed, considering studies from unique centers reporting on pectus excavatum patients who underwent the Nuss procedure. Primary and secondary outcomes were, respectively: the incidence of significant perioperative complications (Clavien-Dindo ≥ grade-III and significant intraoperative complications) and bar displacement. The presence of a non-linear volume-outcome relation was evaluated through restricted-cubic-spline-analyses. If present, the optimal annual institutional case-volume was determined by the elbow method. Forty-nine studies from 49 unique centers were included, enrolling 13,352 patients in total. The significant perioperative complication rate was low [7.7%, 95% confidence interval (CI): 6.4-9.0%] and demonstrated a significant non-linear volume-outcome relation (P<0.001), even after covariate adjustment. The optimal annual institutional case-volume was determined at 73 cases/year (95% CI: 67-89). In this scenario, the number needed to treat to prevent a single perioperative complication compared to a low volume center was 11 (95% CI: 8-19). A similar volume-outcome relation (P<0.001) and optimal case volume of 73 cases/year was observed for bar displacement. A significant volume-outcome relation for repair of pectus excavatum by the Nuss procedure exists with an optimal annual institutional case-volume of 73 cases/year. These findings provide rationale for centralization.

367. IMPACT OF NEOADJUVANT IMMUNOTHERAPY ON POSTOPERATIVE COMPLICATIONS IN RESECTABLE ESOPHAGEAL ADENOCARCINOMA

Abstract Background Several studies are ongoing on the use of immunotherapy in the neoadjuvant setting for esophageal and gastroesophageal junction cancer but it is unclear the effect of an increased activation of the immune system on surgery and the postoperative course. Methods This multicenter retrospective cohort study included data from 3 high-volume centers for upper-GI surgery. Only patients with esophageal adenocarcinoma who underwent neoadjuvant therapy and radical surgery between 2015 and 2022 were included. Clinical characteristics and the postoperative outcomes were compared between patients who received standard neoadjuvant therapy or chemotherapy plus immunotherapy. A 1-to-1 matched comparison was also performed. The difference in overall survival (OS) and disease free survival (DFS) between the two groups was also evaluated. Results Overall, 563 patients were included and 21 received preoperative Pembrolizumab or Trastuzumab combined with at least a couple of chemotherapy drugs. The incidence of complications was 47% in the group with immunotherapy and 40.7% in the other group (p=0.53). The matched analysis confirmed no differences in rate of complications (p&amp;gt;0.99), gravity of complications (p=0.17) and pulmonary complications (p&amp;gt;0.99). Anastomotic leak rate was 4.7% in the immunotherapy group and 19% in the other one (p=0.34). Overall survival and disease free survival were comparable (respectively p=0.4 and p=0.9) also after the matched analysis (respectively p=0.15 and p=0.52). Conclusion Neoadjuvant immunotherapy-based regimen does not affect the postoperative course, in particular it does not appear to aggravate the major complications of esophagectomy.

737. ETHNIC, GENDER AND TUMOR-SPECIFIC ASSESSMENT OF BODY COMPOSITION IS CRITICAL FOR CLINICAL RELEVANCE IN PATIENTS UNDERGOING THERAPY FOR ESOPHAGEAL

Abstract Background Growing evidence has supported a role for body composition in predicting survival in patients undergoing esophagectomy. A contemporary meta-analysis of published data (n=44 studies) conducted for this study confirmed an association between reduced muscle mass at diagnosis and worse overall survival (HR 1.72, 95%CI 1.49-1.97). Variation in methods of assessing and defining parameters of body composition remain however an important barrier to the wider adoption in routine clinical practice. This is particularly pertinent in esophageal cancer due to known sex, biological and geographical difference in tumor subtypes. This study seeks to define baseline variation in body composition parameters and to report their association with 90-day and overall survival in a large international cohort of patients undergoing esophagectomy for cancer. Methods Patients who underwent esophagectomy in fourteen high-volume centers between January 2007 to December 2019 were eligible for inclusion. Survival data were included up until June 2022. Skeletal muscle, visceral and subcutaneous adipose tissues within CT images, acquired at the time of diagnosis, were analyzed in accordance with a standardized protocol. Results 1716 patients were recruited to this study from three global regions: North America (n=386;22.5%), Europe (n=940;54.8%) and Asia (n=390;22.7%). Patients were predominantly male (79.5%) and adenocarcinoma was the most common histological subtype (66.6%). Wide variation of skeletal muscle (17.1-83.5cm2), visceral adiposity (0.2-170.1cm2) and subcutaneous adiposity (0.2-216.8cm2) was observed at presentation. Characteristics significantly associated with levels of muscle and adiposity were global region, sex, age, and histological subtype (P&amp;lt;0.001) (Figure 1). Compared to adenocarcinoma, squamous cell carcinoma was associated with significantly lower levels of muscle and adiposity, a finding that was independent of global region, sex, and age using a multivariable linear regression model (p&amp;lt;.0001). Median follow-up was 71.3 (95%CI 69.1-73.5) months with a median overall survival of 60.9 (95%CI 53.0-68.9) months. Reduced skeletal muscle and an excess of total adiposity at the time of diagnosis was associated with worse 90-day mortality and long-term survival. An interactive online survival prediction tool was developed to provide personalized survival estimates based on relevant predictors including skeletal muscle, total adiposity at diagnosis and other tumor and patient specific variables. Conclusions This is the first and largest study to adopt standardized methods to define international variation in parameters of body composition in esophageal cancer patients. Findings corroborate the potential role of body composition as a method of prognostication in esophageal cancer and presents a on-line tool for convenient integration into clinical practice.

Association between caseload volume and outcomes in left ventricular assist device implantations-a EUROMACS analysis.

This EUROMACS study was conducted with the primary aim of investigating the association between a centre's annual caseload and postoperative outcomes among patients undergoing left ventricular assist device (LVAD) implantation. A total of 4802 patients identified between 2011 and 2020 from 35 participating centres were dichotomized based on the annual caseload of the treating centre at the time of device implant (≤30 vs. >30 LVAD implantations/year). The primary endpoint was 1-year survival. Secondary outcomes included overall survival analysis, device-related adverse events and readmissions. Cumulative follow-up was 10 003 patient-years, with a median follow-up of 1.54 years (interquartile range 0.52-3.15). Patients from higher volume centres more frequently presented in INTERMACS levels 1 and 2, suffered from right heart dysfunction and needed inotropic support. No difference was observed in adjusted 1-year survival. Adjusted overall survival probability was lower in higher volume centres (p = 0.002). In the subgroup analysis of HeartMate 3 devices only, higher volume centres were associated with decreased odds of 1-year survival (adjusted odds ratio 0.43, 95% confidence interval 0.20-0.97, p = 0.041). Similar findings were observed in the cumulative (i.e. learning curve) caseload analyses. In patients undergoing LVAD implantation, centre volume was not associated with 1-year survival, but was related to device-related adverse events. Patient profiles differed with respect to centre size. These findings underscore the necessity for ongoing quality improvement initiatives in all centres, regardless of their annual caseload. Efforts are needed to standardize patient selection and preconditioning to further improve patient outcome.

Analysis of risk factors for persistent PSA after radical prostatectomy: results from a high-volume center in Southeast China

BackgroundFor localized prostate cancer, a comprehensive treatment approach centered around radical prostatectomy (RP) is often their optimal choice. Successful RP can typically reduce prostate-specific antigen (PSA) levels to below 0.1 ng/mL within 6 to 8 weeks postoperatively. However, in clinical practice, 5 to 24% of patients may have a PSA ≥ 0.1 ng/mL at 6 to 8 weeks after surgery, a phenomenon known as PSA persistence. Many studies based on data from Europe and United States have shown an association between PSA persistence and poor postoperative outcomes, further analyzing the risk factors for PSA persistence. However, relevant research based on data from China remains scarce.MethodsRetrospective study of 1,347 prostate cancer patients who underwent RP at the First Affiliated Hospital of Zhejiang University School of Medicine from July 15, 2016, to August 31, 2022. Based on inclusion criteria, univariate and multivariate logistic regression analyses were conducted to explore the independent risk factors for persistent PSA.ResultsAmong the 826 prostate cancer patients after RP, 124 patients experienced persistent PSA. In univariate logistic regression analysis, robot-assisted laparoscopic radical prostatectomy (RARP), preoperative PSA, high-risk group, preoperative International Society of Urological Pathology (ISUP) grades 2–5, postoperative ISUP grades 3–5, percentage of positive cores, cT3, ≥pT3b, extracapsular extension (EPE), seminal vesicle invasion (SVI), positive surgical margins (PSM) and Prostate Specific Antigen Density (PSAD) were all significantly associated with PSA persistence after RP (P < 0.05). In terms of surgical approach, RARP was considered a protective factor against postoperative PSA persistence (OR:0.53, p < 0.05). In multivariate logistic regression analysis, preoperative ISUP grade 4, percentage of positive cores and PSM were independent risk factors of PSA persistence after RP (P < 0.05).ConclusionPreoperative PSA, high-risk group, preoperative ISUP grades 2–5, postoperative ISUP grades 3–5, percentage of positive cores, cT3, ≥pT3b, EPE, SVI, PSM and PSAD were independent risk factors for PSA persistence in prostate cancer patients after RP. This provides assistance for early monitoring and treatment of patients at high risk of persistent PSA in clinical practice.

Outcomes after right-sided colon surgery in Crohn's disease versus cancer.

Surgery for Crohn's disease (CD) is considered to have more complications due to the underlying inflammation, immunosuppression, and malnutrition.We sought to study the outcomes of right-sided colonic resection in patients with CD and patients with cancer at a high-volume tertiary center utilizing a standardized perioperative protocol. This is a retrospective study of outcomes for all patients with CD or patients undergoing ileocolic resection or right hemicolectomy with ileocolic anastomosis at a single institution from 2013 to 2022. Patients were excluded if they simultaneously underwent another procedure or ostomy creation. Data were analyzed using Wilcoxon rank-sum and chi-squared tests for univariate analyses, and logistic and linear regressions for multivariate analyses. In total 141 patients with CD and 589 patients with cancer were included. Patients with CD were significantly younger with lower body mass index and less likely to have comorbidities, including diabetes and hypertension. Patients with CD were less likely to have a smoking history or prior abdominal surgery, but more likely to be on steroids. Both groups had similar rates of laparoscopy, intraoperative complications, and blood loss. Despite the preoperative and intraoperative differences, both patients with CD and patients with cancer had similar lengths of stay (LOS), readmission, reoperation, and mortality rates.None of the surgical outcomes differed significantly between the two groups.On multivariate analysis, CD diagnosis was not associated with reoperation, readmission, mortality, or LOS while controlling for other characteristics. With the use of standardized perioperative protocols, surgery for CD at a high-volume center with expertise in CD can be performed with comparable results to other indications like cancer.