EP.WE.324Variation Between Observed and Perceived Volume of Antireflux Operations Completed by Upper-Gastrointestinal Surgeons at a University Teaching Hospital

Aims Increased institutional volume and surgeon experience with antireflux surgery has been shown to improve patient outcomes. We have sought to illustrate the discrepancy between the perceived (self-reported) and observed annual volume of anti-reflux operations completed by each surgeon. Method A retrospective questionnaire was delivered to all upper-gastrointestinal (UGI) surgeons performing antireflux surgeries (ARS) at a University Teaching Hospital. Surgeons were asked to estimate the quantity of NHS antireflux cases completed annually. Objective, anonymised data was retrieved from the Surgical Workload Outcomes Audit Database (SWORD) from 2017 to 2020 for comparison. Results 127 ARS were completed by 6 UGI consultants between January 2018 and December 2020. The median number of ARS completed per surgeon was 5 (2-10) in 2018, 9 (4-11) in 2019 and 10 (1-11) in 2020. Conversely, the median number of self-reported annual procedures per surgeon was 20 (12-35). On average, participants overestimated the number of NHS ARS completed by 14.5 (4-27) cases or a factor of 2.08. No surgeon correctly or underestimated the number of ARS performed. Conclusion We conclude that self-reported operation volume should not be relied upon for the purposes of assessment or audit. Estimations of annual ARS procedures could be up to triple that suggested by objective data. Our data supports the importance of local or national data sets like SWORD to give an accurate reflection of practice and to allow individuals to compare their performance against their peers.

788 Variation Between Observed and Perceived Volume of Antireflux Operations Completed by Upper-Gastrointestinal Surgeons at a University Teaching Hospital

Aim Increased institutional volume and surgeon experience with antireflux surgery has been shown to improve patient outcomes. We have sought to illustrate the discrepancy between the perceived (self-reported) and observed annual volume of anti-reflux operations completed by each surgeon. Method A retrospective questionnaire was delivered to all upper-gastrointestinal (UGI) surgeons performing antireflux surgeries (ARS) at a University Teaching Hospital. Surgeons were asked to estimate the quantity of NHS antireflux cases completed annually. Objective, anonymised data was retrieved from the Surgical Workload Outcomes Audit Database (SWORD) from 2017 to 2020 for comparison. Results 127 ARS were completed by 6 UGI consultants between January 2018 and December 2020. The average number of ARS completed per surgeon was 5.8 (2-10) in 2018, 8.7 (4-11) in 2019 and 6.7 (1-11) in 2020. Conversely, the average number of self-reported annual procedures per surgeon was 22.4 (12-35). On average, participants overestimated the number of NHS ARS completed by 14.5 (4-27) cases or a factor of 2.08. No surgeon correctly or underestimated the number of ARS performed. Conclusions We conclude that self-reported operation volume should not be relied upon for the purposes of assessment or audit. Estimations of annual ARS procedures could be up to triple that suggested by objective data. We recommend that all surgeons maintain a database of ARS for the purpose of self-assessment and audit.

Abstract 16110: Impact of Institutional Volume on In-hospital Mortality and Resource Utilization Among Patients With Pulmonary Embolism Treated With Catheter Directed Thrombolysis: A Population-Based Cohort Study

Introduction: Catheter-directed thrombolysis (CDT) is an evolving percutaneous approach for the management of acute pulmonary embolism (PE). Contemporary data examining in-hospital outcomes in relation to procedural volume are limited. Methods: Data sets were extracted from the 2016 national readmission database. Using ICD 10 codes, a search was performed to identify all patients hospitalized with a primary or secondary diagnosis of PE who underwent CDT between 1/1/2016 and 12/31/2016. Hospitals were grouped into quartiles by CDT volume and rates of in-hospital mortality, length of stay, and cost were compared across groups. Adjusted associations were examined using multivariable logistic regression. Results and Conclusions: We identified 2,353 unique patients with PE who underwent CDT at 483 hospitals. The median (25th, 75th percentiles) number of CDT procedures per hospital was 3 (1, 6). Mortality rates were 11.4%, 5.3%, 5.6% and 3.8%, respectively, at hospitals in the 1st, 2nd, 3rd and 4th quartile of CDT procedural volume (Figure; p=0.001). Results were unchanged after multivariable adjustment. Median length of stay by quartile was as follows: 6.5, 5, 5, and 4 days (p <0.001). The median cost for the different quartiles was $28,277, $25,953, $25,896, and $23,007 (p <0.001). We found that CDT performed in patients with PE at low-volume hospitals is associated with excess mortality as well as increased length of stay and cost when compared with higher-volume centers. These findings may inform guidance for volume thresholds for utilization of CDT in the management of acute PE.

Higher Institutional Volume Reduces Mortality in Reoperative Proximal Thoracic Aortic Surgery

Objective This study aims to determine the impact of institutional volume on mortality in reoperative proximal thoracic aortic surgery patients using national outcomes data. Methods The Nationwide Inpatient Sample was queried from 1998 to 2011 for patients with diagnoses of thoracic aneurysm and/or dissection who underwent open mediastinal repair. A total of 103,860 patients were identified. A total of 1,430 patients had prior cardiac surgery. Patients were further stratified into groups by institutional aortic volume: low (<12 cases/year), medium (12–39 cases/year), and high (40+ cases/year) volume. Multivariable risk-adjusted analysis accounting for emergent status and aortic dissection among other factors was performed to determine the impact of institutional volume on mortality. Results Overall mortality was 12% in the reoperative population. When the redo cohort was divided into tertiles, high-volume group had a 5% operative mortality compared with 9 and 15% for the medium- and low-volume groups, respectively. Multivariable analysis revealed that patients operated on at low- (odds ratio [OR] = 5.0, 95% confidence interval [CI]: 2.6–9.6, p < 0.001) and medium-volume centers (OR = 2.1, 95% CI: 1.1–4.2, p = 0.03) had higher odds of mortality when compared with patients operated on at high-volume centers. Conclusions High-volume aortic centers can significantly reduce mortality for reoperative aortic surgery, compared with lower volume institutions.

Impact of Institutional Volume on Critical In-Hospital Complications Adjusted for Patient- and Limb-Related Characteristics: An Analysis of a Nationwide Japanese Registry of Endovascular Interventions for PAD

Purpose: To investigate the incidence and clinical predictors, including institutional annual case volume, of critical in-hospital complications after endovascular therapy (EVT) for peripheral artery disease (PAD). Materials and Methods: The data were extracted from the nationwide registry of peripheral interventions in Japan [Japanese EVT (J-EVT)] between 2012 and 2017. A total of 92,224 EVT cases either for chronic limb-threatening ischemia (CLTI) or intermittent claudication were included in the analysis. The primary outcome measure was critical in-hospital complications, which were defined as a composite of urgent surgery and in-hospital death within 30 days after EVT. The institutional volume was classified into quartiles. The association of institutional volume, as well as baseline characteristics, with the critical in-hospital complications was explored using a multivariable logistic regression model with multiple imputation for missing data. Results are presented as the adjusted odds ratio (OR) with the 95% confidence intervals (CI). Results: The estimated prevalence of critical in-hospital complications was 0.3% (95% CI 0.3% to 0.4%). The following 10 patient- and limb-related characteristics were identified as independent risk factors for critical in-hospital complications: (1) female sex (OR 1.75, 95% CI 1.36 to 2.25), (2) age ≥75 years (OR 1.60, 95% CI 1.06 to 2.40), (3) CLTI (OR 2.12, 95% CI 1.47 to 3.05), (4) nonambulatory status (OR 1.66, 95% CI 1.23 to 2.24), (5) regular dialysis (OR 1.35, 95% CI 1.02 to 1.77), (6) cerebrovascular disease (OR 1.76, 95% CI 1.33 to 2.33), (7) urgent revascularization (OR 5.10, 95% CI 3.64 to 7.13), (8) aortoiliac TASC II D lesion (OR 3.65, 95% CI 2.51 to 5.33), (9) femoropopliteal TASC II D lesion (OR 1.77, 95% CI 1.24 to 2.52), and (10) infrapopliteal TASC D lesion (OR 1.52, 95% CI 1.08 to 2.13). In addition, the 4th quartile of the institutional volume (≥158 cases/year), but not the 2nd or 3rd quartile, had a significantly and independently lower risk of critical in-hospital complications than the 1st quartile (OR 0.13, 95% CI 0.07 to 0.23). Conclusion: After EVT for symptomatic PAD, 0.3% of the population encountered critical in-hospital complications. A higher institutional volume was significantly associated with a lower risk of critical in-hospital complications.

Impact of Septal Myectomy Volume on Mitral-Valve Replacement Rate in Hypertrophic Cardiomyopathy Patients

Objective: Mitral regurgitation (MR) induced by systolic anterior motion in patients with hypertrophic cardiomyopathy (HCM) can frequently be abolished with a proficient septal myectomy (SM) without the need for mitral-valve replacement (MVR). ACC guidelines stress the importance of volume in improving outcomes after SM, but there is a lack of data measuring the impact of volume on the need for MVR during SM. This study was designed to assess the impact of institutional volume on MVR rates using national outcomes data. Methods: The Nationwide Inpatient Sample was queried from 1998 to 2011 and a total of 6,207 patients had a diagnosis of HCM and a procedure code for SM. Outcomes were compared between patients who underwent SM (group I) and SM and MVR (group II). Furthermore, patients were stratified into 3 groups based on the number of SMs at the performing institution: low experience (1–24 cumulative SMs), medium experience (25–49 SMs), and high experience (>50 SMs). These patients underwent multivariable analysis to determine the impact of institutional volume on MVR rate. Results: The total MVR rate was 26%. Perioperative outcomes were worse, i.e., there were higher rates of mortality, kidney injury, and urinary complications, in group II than in group I. Only 37.6% of patients were operated on at institutions meeting the guideline criteria of >50 cumulative SMs. When compared to patients in the high-experience group, patients in the low- (OR 2.7, 95% CI 2.3–3.2, p < 0.05) and medium-experience (OR 3.0, 95% CI 2.5–3.6, p < 0.05) groups were more likely to undergo MVR. Conclusion: Compared to reports from SM reference centers, national data suggest that MVR rates are quite high at SM. Patients undergoing SM at centers that do not meet the guideline standard have >2.5× the odds of undergoing MVR compared to those operated on at guideline-endorsed centers.

P5605The impact of institutional case volume on the Ppognosis of ruptured aortic aneurysms: a Japanese nationwide study

Background To improve outcome for ruptured aortic aneurysms (rAA), centralization of treatment is potentially effective. However, there is no nationwide survey for the current managements and outcomes of rAA in Japan. Purpose The aim of this study was to assess the volume-outcome relationship for rAA treatment using the nationwide claim-based database. Methods Using the Japanese Registry Of All cardiac and vascular Diseases- Diagnostic Procedure Combination database, we identified patients admitted to 564 certified teaching-hospitals with rAA between April 1, 2012 and March 31, 2015. Institutional case volume (cardiovascular surgeries per year) was categorized into quartiles (Lowest, Low, High, and Highest) and the odds ratios (ORs) for in-hospital mortality and neurological status at discharge were analyzed for each quartile. Results Of 7086 eligible patients, 3925 (55.4%) died in hospital. Mortality rates decreased from 69.4% in the lowest-volume to 43.8% in the highest-volume category (P<0.001). The favourable impact of institutional case volume was sustained even after adjustment for covariates (Low-volume: OR, 0.83; 95% confidence interval [CI], 0.65–1.07; P=0.147; High-volume: OR, 0.69; 95% CI, 0.54–0.89; P=0.005; and Highest-volume: OR, 0.55; 95% CI, 0.42–0.72; P<0.001 vs. Lowest-volume). Additionally, other three institutional parameters (increased aortic surgery volume, cardiovascular surgeons' volume, and certified cardiologists' volume) were consistently associated with reduced in-hospital mortality. The rate of coma at discharge was the lowest in the Highest-volume group (P<0.001). Institutional volume and mortality Conclusions Increased institutional volume was associated with lower in-hospital mortality. Establishing regionally tailored systems to transfer patients to high-volume centers is needed to improve outcomes.

Institutional volume affects long-term survival following lung transplantation in the USA

OBJECTIVES The aim of this study was to evaluate the impact of institutional volume on long-term outcomes following lung transplantation (LTx) in the USA. METHODS Adults undergoing LTx were identified in the United Network for Organ Sharing registry. Patients were divided into equal size tertiles according to the institutional volume. All-cause mortality following LTx was evaluated using the risk-adjusted multivariable Cox regression and the Kaplan–Meier analyses, and compared between these volume cohorts at 3 points: 90 days, 1 year (excluding 90-day deaths) and 10 years (excluding 1-year deaths). Lowess smoothing plots and receiver-operating characteristic analyses were performed to identify optimal volume thresholds associated with long-term survival. RESULTS A total of 13 370 adult LTx recipients were identified. The mean annual centre volume was 33.6 ± 20.1. After risk adjustment, low-volume centres were found to be at increased risk for 90-day mortality, [hazard ratio (HR) 1.56, P < 0.001], 1-year mortality excluding 90-day deaths (HR 1.46, P < 0.001) and 10-year mortality excluding 1-year deaths (HR 1.22, P < 0.001). These findings persisted when the centre volume was modelled as a continuous variable. The Kaplan–Meier analysis also demonstrated significant reductions in survival at each of these time points for low-volume centres (each P < 0.001). The 10-year survival conditional on 1-year survival was 37.4% in high-volume centres vs 28.0% in low-volume centres (P < 0.001). The optimal annual volume threshold for long-term survival was 26 LTx/year. CONCLUSIONS The institutional volume impacts long-term survival following LTx, even after excluding deaths within the first post-transplant year. Identifying the processes of care that lead to longer survival in high-volume centres is prudent.