Volume Centers Research Articles

Does Trauma Center Volume Matter? An Analysis of Trauma Center Volume on Outcome Using the TQIP/NTDB Database

Background: Increasing trauma center admission volume is said to decrease mortality. Evidence supporting this position is dependent upon patient groups and the time period studied, and gaps remain. We evaluated the effect of annual volume of critically injured patients on hospital mortality, comparing two time periods. The effect of critically injured patient volume on risk-adjusted mortality was hypothesized to decrease over time. Methods: This was a retrospective cohort study comparing data from an early group (2007–2011) and late group (2017–2021) of the National Trauma Data Bank. Critically injured adults (ISS > 15) admitted to the intensive care unit (ICU) or operating room from the emergency department at Level I and II trauma centers were included. The outcome of interest was risk-adjusted mortality across quintiles of patient admission volume, modeled using mixed-effects generalized linear models. Results: In total, 802,824 patients were included, 321,209 and 481,615 in the early and late groups, respectively. In the early group, increased patient volume was associated with a decreased risk-adjusted odds of mortality. This association was not seen in the late group. The overall odds of mortality in the late group demonstrated decreased mortality over time (OR 0.84, p < 0.001). Conclusions: The annual volume of critically injured patients was associated with decreased odds of hospital mortality during 2007–2011, though this effect was no longer present in the 2017–2021 sample. The continued dissemination of the best practices is warranted to decrease mortality, regardless of the admission volume of critically injured patients.

Analysis of Surgeon and Center Case Volume and Stroke or Death after Transcarotid Artery Revascularization.

It has been suggested that the annual hospital volume of cases may affect the number of adverse events following carotid endarterectomy (CEA). We aim to study the associations between hospital as well as surgeon volume and the risk of stroke/death following TCAR. Retrospective review of the Vascular Quality Initiative data of patients undergoing TCAR from 2016 to 2021. Surgeon and center volume were calculated based on the mean number of cases (MNC) performed yearly by each surgeon and center. The primary outcome was a composite endpoint of in-hospital stroke/death. A total of 22,624 cases were included. Surgeon volume was divided into three quantiles: low (MNC=4), medium (MNC=10), and high (MNC=26). Center volume was also divided into low (MNC=14), medium (MNC=32), and high (MNC=64). After adjusting for potential confounders, and when compared to high volume centers, low and medium center volume was not associated with any increased odds of in-hospital stroke/death, stroke, death, or stroke/TIA. Compared to high volume surgeons, low surgeons' volume was associated with a higher odd of stroke (OR: 1.5, 95%CI (1.1-2.04), P=0.008), and stroke/TIA (OR: 1.5, 95%CI (1.2-1.9), P=.002). However, medium surgeon volume was not associated with higher odds of stroke/death, stroke, and stroke/TIA. Neither low nor medium surgeon volume was associated with a difference in mortality compared to high surgeon volume. In this retrospective study, center volume was not associated with any differences in outcomes among patients undergoing TCAR. On the other hand, surgeons with low volume were associated with a higher risk of stroke/death/MI and stroke/TIA when compared to high surgeon volume. There was no difference in outcomes between medium and high surgeon volume.

A national study of infective endocarditis models of care in Australia.

Multidisciplinary endocarditis team (MDET) management is supported by current evidence and recommended in international society guidelines. The extent to which this recommendation has been implemented in Australian centres and the attitudes, barriers and facilitators of this model are unclear. To describe current infective endocarditis (IE) models of care in Australian specialist referral centres and evaluate facilitators, barriers and attitudes towards MDET implementation. Aims were addressed using two online surveys. Survey 1 audited IE models of care and was distributed to infectious disease physicians at specialist referral centres. Survey 2 assessed barriers, facilitators and attitudes towards MDETs and was distributed via societal email listings. From 56 identified cardiac surgery centres, survey 1 received 47 responses (84%). A total of 28% (13/47) of participating institutions had an existing MDET. A total of 85% (11/13) of MDETs were in public hospitals and 85% (11/13) were in high IE volume centres. Survey 2 had 109 respondents from seven specialties. Attitudes towards MDET implementation were generally favourable. Identified barriers to MDET implementation included a lack of funding, resources, expertise, time and collaboration. Facilitators included strong leadership, engagement from key stakeholders and tangible benefits. Even though it is recommended in international guidelines, the MDET model is used by less than one-third of Australian specialist referral centres. Stakeholders in IE care have generally favourable attitudes towards MDET implementation but cite a lack of resources, funding, collaboration and time as barriers to this. Dedication of financial and administrative support and leadership from key stakeholders are required to increase MDET utilisation.

Comparison of waitlist and post-transplant outcomes in patients supported with total artificial heart versus continuous biventricular assist devices.

Durable biventricular support may be necessary to bridge patients with end-stage biventricular failure to heart transplantation. This study compares waitlist and post-transplant outcomes between patients supported with continuous flow, durable biventricular assist devices (BiVAD), and total artificial heart (TAH). Using the UNOS registry, we analyzed adult (≥18 years old), first-time transplant candidates with TAH or BiVAD at the time of listing or transplantation from 10/1/2010-10/31/2020, with follow-up through 3/31/2022. Multivariable proportional subdistribution hazards models and cause-specific Cox proportional hazards models were used to compare death/deterioration or heart transplantation on the waitlist between cohorts. Kaplan-Meier and multivariable Cox proportional hazards model were used to evaluate one-year post-transplant survival and evaluate difference in outcomes based on annual transplant center volume. The waitlist cohort included a total of 228 patients (25% BiVAD). Waitlist outcomes between device types were similar. The transplanted cohort included a total of 352 patients (25% BiVAD). There was a trend towards worse one-year post-transplant survival in patients bridged with TAH versus BiVAD (log-rank p-value = 0.072) that persisted after adjusting for age, gender, policy, and removing dual-organ recipients (HR 1.94 (0.94, 3.98) p-value = 0.07). There was a difference in one-year post-transplant survival amongst TAH-bridged patients when stratified by annual transplant center volume (log-rank p-value = 0.013). One-year post-transplant survival between TAH-supported patients from high annual transplant volume centers and BiVAD-supported patients was similar (p-value = 0.815). BiVAD and TAH are reasonable support strategies with TAH implantation at high-volume transplant centers (51+ transplants/year) having similar 1-year post-transplant survival to BiVAD-supported patients.

National Trends and Outcomes of Pedal Bypass Surgery

ObjectiveThe technical demands associated with pedal bypass (PB) surgery place it at risk of underutilization and may be limiting its widespread adoption as a valuable revascularization modality. This study aims to evaluate trends in PB performance, assess its outcomes, and compare its results between high- and low-volume centers. MethodsAll patients receiving a PB between 2003 and 2023 were identified in the Vascular Quality Initiative (VQI) infrainguinal bypass (IIB) module. The ratio of PB to total IIB performed was calculated for each year and trended over the study period. Centers performing PB were categorized according to their annual PB volume into tertiles of low-volume centers (LVC, <2 PB/year), medium-volume centers (MVC, 2-4 PB/year), and high-volume centers (HVC, >4 PB/year) for comparison. Patient characteristics and outcomes were compared using the χ2 or Fisher exact test as appropriate for categorical variables and the analysis of variance test or Kruskal-Wallis test as appropriate for continuous variables. Cox regression analysis was used to study the association between center volume and the primary outcomes of primary patency, primary-assisted patency, secondary patency, reintervention, amputation, and major adverse limb events (MALE), defined as the composite outcome of amputation and/or reintervention. ResultsA total of 3466 patients received a PB during the study period. The ratio of PB to IIB dropped from 14% to 4% between 2003 and 2023. Primary, primary-assisted, and secondary patency rates were 65%, 76%, and 80%, respectively, and limb salvage rate was 83% at 1 year. Nineteen percent of centers performing IIBs in the VQI did not perform any PBs during the study period. Of the 246 centers performing PBs, 78% were LVC, 15% were MVC, and only 7% were HVC. On Cox regression analysis, HVCs were associated with a lower risk of primary patency loss (hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.66-0.95; P = .010), reintervention (HR, 0.75; 95% CI, 0.60-0.95; P = .016), amputation (HR, 0.77; 95% CI, 0.61-0.98; P = .034), and MALE (HR, 0.78; 95% CI, 0.66-0.93; P = .005) compared with LVCs. No difference in secondary patency between high- and low-volume centers was observed (P = .680). ConclusionsThe utilization of PB operations experienced a four-fold decrease over the past 20 years, despite favorable patency and limb salvage outcomes. Centers with a higher operative volume in PB achieve better outcomes than LVCs, and accordingly, patients with extensive tibioperoneal disease may benefit from evaluation at centers with documented expertise in PB before resorting to an alternative revascularization modality or a major limb amputation.

Impact of Center Volume on the Use of Status 2 Exceptions for Heart Transplantation.

There are limited data examining the relationship between transplant center volume and their use of Status 2 exceptions for heart transplant (OHT). A retrospective review of the Organ Procurement and Transplantation Network (OPTN) database identified all patients undergoing OHT under Status 2 exception between late 2018 and early 2023. Demographics were collected and transplant centers were categorized based on the number of OHT performed annually (very low volume = < 5 OHT per year; low volume = 5-24 OHT per year; medium volume = 25-50 OHT per year, high volume = > 50 OHT per year). Across all centers, 6348 OHT were included, with n = 68 performed at very low volume centers, n = 1001 performed at low volume centers, n = 1834 performed at medium volume centers, and n = 3445 performed at high volume centers. Medium and high volume centers applied for at least one Status 2 exception about 30%-35% of the time, compared to 50%-60% of the time observed at very low and low volume centers. Compared to very low volume centers, medium volume centers applied for half the amount of Status 2 exceptions (IRR = 0.52 [0.35-0.76]; p < 0.001) while high volume centers applied for less than half the amount (IRR = 0.42 [0.29-0.62]; p < 0.001). High-volume centers were also 18% less likely to apply for exceptions than medium-volume centers (IRR = 0.82 [0.74-0.91]; p < 0.001). Lower volume transplant centers apply for Status 2 exceptions at a significantly higher rate, with a stepwise decrease in exception use with increasing transplant center volume.

Comparison of Open and Endovascular Repair of Complex Abdominal Aortic Aneurysms

To compare perioperative and 5-year outcomes following endovascular (FEVAR) and open repair (OAR) of complex abdominal aortic aneurysms (cAAA) in males and females separately, given the known sex related differences in perioperative outcomes. We studied all elective cAAA repairs between 2014-2019 in the Vascular Implant Surveillance and Interventional Outcomes Network (VISION) registry. We stratified patients based on sex. We calculated propensity scores for assignment to either OAR or FEVAR. Covariates including age, race, diameter, baseline comorbidities, proximal extent of repair, annual center volumes, and annual surgeon volumes were introduced into the model for estimating propensity scores. Within matched cohorts, perioperative outcomes and 5-year outcomes (mortality, reinterventions, and ruptures) were evaluated using multivariable logistic and Cox regression models. We identified 2,825 patients of whom 29% were female. Within both the sexes, OAR was more commonly performed (OAR vs FEVAR: males: 53% vs 47%; females: 63% vs 37%). After matching, among males (n=1326), FEVAR was associated with lower perioperative mortality (FEVAR vs OAR: 2.3% vs 5.1%; p<.001). However, FEVAR was associated with comparable 5-year mortality (38% vs 28%; hazard ratio (HR) 1.2 [0.92-1.4]; p=.22) and a higher hazard of 5-year reintervention (19% vs 3.7%; aHR: 4.5 [2.6-7.6], p<.001). Among females (n=456), FEVAR and OAR showed similar perioperative mortality (8.3% vs 7.0%; p=.73). At 5 years, FEVAR was associated with higher hazards of mortality (43% vs 32%; aHR: 1.5 [1.03-2.2], p=.034) and reintervention (20% vs 3.0%; aHR: 4.8 [2.1-11], p<.001) compared with OAR. Among males, FEVAR was associated with favorable perioperative outcomes compared with OAR, though these advantages attenuate over time. However, among females, FEVAR was associated with similar perioperative outcomes, eventually leading to higher reinterventions and possibly higher mortality within 5 years. Future efforts should focus on determining the factors associated with these sex disparities to improve outcomes following FEVAR in females. Based on current evidence, females undergoing elective cAAA repair should be selected with due caution, especially for endovascular repair.

Treatment of Domestic Wastewater Using Membrane Bioreactor (MBR) Pilot Plant: A Case Study of Wastewater from Kklung Hok’s Treatment Pond and The Environmental Research and Training Centre (ERTC), Pathumthani, Thailand

This research performant of Membrane Bioreactor (MBR) pilot plant for treatment of Wastewater from Khlung Hok’s treatment pond volume of 250 liter and The Environmental Research and Training Centre (ERTC) volume of 100 liter, both wastewater was mix on MBR. Aeration was fed at air flow rate 150 l/min over two hours to provide the oxygen for microorganisms. Further, Aeration was fed continuously for 6 hours. sample were collected every one hour. Result found that: the wastewater variation of pH, DO, BOD, COD, NH4+, NO2– concentration of the feed tank from Khlung Hok’s treatment pond were 7.16, 0.60 mg/l, 95mg/l, 157 mg/l, 34.96 ppm and NO2 not found and from ERTC’s wastewater were 6.87, 0.41 mg/l, 93 mg/l, 160 mg/l, 21.23 ppm and 0.043 ppm, respectively. After air flow in MBR over 2 hour the concentration of influent was found 6.64, 0.60 mg/l, 48 mg/l, 105.67 mg/l, 22.30 ppm and 0.031 ppm, respectively. And during the whole process effluent pH concentration were between 6.64-7.46, DO were between 1.11-5.8 mg/l. The removal BOD efficiency were over 89.58% (on 5th hour), COD were over 75.39% (on 4th hour), NH4 were over 53.61% of (on first hour) and were over NO2 48.71% of (on 2nd hour), respectively. Result indicated that effective removal BOD, COD, NH4+ and NO2– by MBR could be achieved and increased in scale for use in the fieldwork or the treatment of wastewater in the environment.

Clinical Outcomes in Relation to Total Hospital Surgical and Transcatheter Aortic Valve Replacement Volumes.

There is a paucity of data regarding the relationship between overall hospital volumes for total aortic valve replacement (AVR; transcatheter AVR [TAVR] or surgical AVR [SAVR]) and patient outcomes. We queried the 2019 Nationwide Readmission Database for patients undergoing AVR. Based on procedural volumes of TAVR or SAVR, we classified hospitals as high (≥50th percentile) or low (<50th percentile) volume centers and categorized hospitals as high TAVR/high SAVR, high TAVR/low SAVR, high SAVR/low TAVR, and low TAVR/low SAVR. Multivariable regression models were employed. The main study outcomes were in-hospital mortality and 30-day readmission after total AVR. Our final analysis included 72 123 patients undergoing AVR at 400 hospitals across the United States. The median (interquartile range) hospital procedural volumes for total AVR, TAVR, and SAVR were 137 (86-210), 82 (50-127), and 56 (31-87) procedures, respectively. There was an inverse correlation between hospital procedural volumes of AVR, TAVR, or SAVR and in-hospital mortality after total AVR but not with 30-day readmission. Using high TAVR/high SAVR hospitals as reference, there was higher in-hospital mortality after total AVR among low TAVR/low SAVR hospitals (adjusted odds ratio [OR], 1.29 [95% CI, 1.07-1.56]) but similar in-hospital mortality among high TAVR/low SAVR hospitals and low TAVR/high SAVR volumes. There was no difference in 30-day readmission rates after total AVR among the 4 hospital categories. Nationwide data revealed that in-hospital mortality after total AVR (SAVR or TAVR) is inversely related to hospital total volumes of AVR. Patients with aortic stenosis have better outcomes if they are managed among experienced centers with high case volumes of both TAVR and SAVR.

Robotic-assisted versus laparoscopic-assisted extended mesorectal excision: a comprehensive meta-analysis and systematic review of perioperative and long-term outcomes.

Concurrent neoadjuvant chemo-radiation (nCRT) with total mesorectal excision (TME) alone sometimes fails to cure lateral lymph node metastasis (LLNM). Therefore, additional lateral lymph node dissection (LLND) can help in the treatment of these patients. This is what we refer to as extended total mesorectal excision (eTME). Such operations (TME alone or eTME) can be performed using conventional laparoscopic techniques and robotic-assisted techniques as well. Our meta-analysis aims to compare the results of robot-assisted (R-eTME) versus laparoscopic-assisted extended mesorectal excision (L-eTME) in terms of short- and long-term outcomes. Databases searched using title and abstract included Medline (via PubMed), Web of Science, Scopus, and Embase, up to February 20, 2024. All studies that documented robotic versus laparoscopic procedures for extended total mesorectal excision (R-eTME versus L-eTME) and reported more than two relevant outcomes, were included in the study. Our meta-analysis demonstrates four significant outcomes (operative time, urinary complications, overall recurrence, and admission days) between the laparoscopic and robotic groups. The robotic approach shows advantages over the laparoscopic approach in these outcomes except for the operative time (minute), which was longer in the robotic group compared to the laparoscopic group. The laparoscopic group is associated with a higher overall recurrence than the robotic group with an Odds Ratio of 2(95% CI, 1-4, p = 0.05). This meta-analysis study showed that the R-eTME group had a lower recurrence rate compared to the L-eTME group. Additionally, hospital admission days increased significantly in the laparoscopic group. Other long-term outcomes did not differ significantly between the two groups. Short-term outcomes were similar, except for more urinary complications in the laparoscopic group. In conclusion, the study suggests that robotic surgery may offer advantages over laparoscopic surgery for eTME. Further research and analysis could provide further insight into the potential benefits of robotic surgery in this procedure, particularly when surgeon experience, center volume, and learning curve are taken into consideration.

Incidence and Outcomes of Iatrogenic Complete Atrioventricular Block After Congenital Heart Surgery

BackgroundIatrogenic complete atrioventricular block (ICAVB) has long been noted as a major complication after congenital heart surgery (CHS), and it contributes to complex postoperative care and potentially affects patients’ outcomes. MethodsThis study is a retrospective review of the Pediatric Health Information System database from January 1, 2004 to September 30, 2023. All patients who underwent The Society of Thoracic Surgeons benchmark procedures were included. International Classification of Diseases (ICD) 9th and 10th editions were used to identify diagnoses and procedures. All patients with a diagnosis of complete atrioventricular block and placement of a permanent pacemaker after CHS but in the same hospitalization were identified as having ICAVB. ResultsA total of 42,332 patients were identified, with 17,106 (41%) female and 23,042 (55%) non-Hispanic White and with a median age of 5.4 months [interquartile range, 0.4-25.8 months]. Of those patients, 246 (0.6%) had ICAVB. The procedure with the highest incidence of ICAVB was the arterial switch operation with ventricular septal defect (VSD) repair (74 of 1552; 4.5%). On multivariable analysis, the arterial switch operation with VSD repair had the highest adjusted odds of ICAVB (odds ratio, 5.41; 95% CI, 3.57-8.19; P < .001) when compared with isolated VSD repair. A diagnosis of endocarditis was significantly associated with ICAVB. Center volume was not associated with ICAVB. ICAVB was associated with a 121% (95% CI, 98.5%-146.8%) increase in length of stay (P < .001) and increased in-hospital mortality (odds ratio, 2.26; 95% CI, 1.34-3.82; P < .001). ConclusionsThe overall incidence of ICAVB after CHS is low. However, certain procedures have incidences as high as 4.5%. ICAVB is associated with increased postoperative mortality and length of stay. Further work is needed to identify drivers of variation among centers to improve overall outcomes.

Hospital volume does not mitigate the impact of area socioeconomic deprivation on heart transplantation outcomes.

While structural socioeconomic inequity has been linked with inferior health outcomes, some have postulated reduced access to high-quality care to be the mediator. We assessed whether treatment at high-volume centers(HVC) would mitigate the adverse impact of area deprivation on heart transplantation(HT) outcomes. All HT recipients ≥18years were identified in the 2005-2022 Organ Procurement and Transplantation Network. Neighborhood socioeconomic deprivation was assessed using the previously validated Area Deprivation Index. Recipients with scores in the highest quintile were considered Most Deprived (others: Less Deprived). Hospitals in the highest quartile by cumulative center volume (≥21 transplants/year) were classified as HVC. The primary outcome was post-transplant survival. Of 38,022 HT recipients, 7,579 (20%) were considered Most Deprived. Following risk adjustment, Most Deprived demonstrated inferior survival at 3(hazard ratio[HR] 1.14, 95%confidence interval[CI] 1.06-1.21) and 5 years following transplantation (HR 1.13, CI 1.07-1.20). Similarly, Most Deprived faced greater graft failure at 3(HR 1.14, CI 1.06-1.22) and 5 years (HR 1.13, CI 1.07-1.20). Evaluating patients transplanted at HVC, Most Deprived continued to face greater mortality at 3(HR 1.10, CI 1.01-1.21) and 5 years (HR 1.10, CI 1.01-1.19). The interaction between Most Deprived status and care at HVC was not significant, such that transplantation at HVC did not ameliorate the survival disparity between Most and Less Deprived. Area socioeconomic disadvantage is independently associated with inferior survival. Transplantation at HVC did not eliminate this inequity. Future efforts are needed to increase engagement with longitudinal follow-up care and address systemic root causes to improve outcomes.

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.

Increasing Multiorgan Heart Transplantations From Donation After Circulatory Death Donors in the United States.

Donation after circulatory death (DCD) donors are becoming an important source of organs for heart-transplantation (HT), but there are limited data regarding their use in multiorgan-HT. Between January 2020 and June 2023, we identified 87 adult multiorgan-HTs performed using DCD-donors [77 heart-kidney, 6 heart-lung, 4 heart-liver] and 1494 multiorgan-HTs using donation after brain death (DBD) donors (1141 heart-kidney, 165 heart-lung, 188 heart-liver) in UNOS. For heart-kidney transplantations (the most common multiorgan-HT combination from DCD-donors), we also compared donor/recipient characteristics, and early outcomes, including 6-month mortality using Kaplan-Meier (KM) and Cox hazards-ratio (Cox-HR). Use of DCD-donors for multiorgan-HTs in the United States increased from 1% in January to June 2020 to 12% in January-June 2023 (p < 0.001); but there was a wide variation across UNOS regions and center volumes. Compared to recipients of DBD heart-kidney transplantations, recipients of DCD heart-kidney transplantations were less likely to be of UNOS Status 1/2 at transplant (35.06%vs. 69.59%) and had lower inotrope use (22.08%vs. 43.30%), lower IABP use (2.60%vs. 26.29%), but higher durable CF-LVAD use (19.48%vs. 12.97%), all p < 0.01. Compared to DBD-donors, DCD-donors used for heart-kidney transplantations were younger [28(22-34) vs. 32(25-39) years, p=0.004]. Recipients of heart-kidney transplantations from DCD-donors and DBD-donors had similar 6-month survival using both KM analysis, and unadjusted and adjusted Cox-HR models, including in propensity matched cohorts. Rates of PGF and in-hospital outcomes were also similar. Use of DCD-donors for multiorgan-HTs has increased rapidly in the United States and early outcomes of DCD heart-kidney transplantations are promising.

Centralized Static Ex-Vivo Lung Perfusion in the United States

Ex-vivo lung perfusion (EVLP) may improve donor lung utilization but requires significant infrastructure and expertise. Centralized EVLP facilities may mitigate these requirements. From the United Network for Organ Sharing database, we identified 345 adults undergoing isolated, first-time lung transplantation using donor lungs perfused by static EVLP (03/01/2018-12/31/2022). Recipients of lungs perfused at centralized EVLP facilities (n=165) were compared to recipients of lungs perfused at individual transplant centers (n=180). Propensity score matching was used to create balanced groups for comparison. Centralized EVLP facilities were increasingly utilized from 2018 to 2022 (35.3 vs. 55.8%, p=0.04) and were more likely used when the annual center volume of EVLP lung transplants was low. Compared to allografts placed on EVLP at individual transplant centers, those placed on EVLP at centralized facilities had longer median ischemic time (11.3 vs. 9.6 hours, p<0.001) and were less likely to come from donation after circulatory death donors (25.4 vs. 39.5%, p=0.003) or be used for double lung transplant (73.3 vs. 83.9%, p=0.02). In 102 well-matched recipients, 2-year survival was equivalent between those receiving allografts perfused at centralized facilities (77.9% [95% CI 68.0-85.1%]) versus individual transplant centers (77.7% [95% CI 67.8-84.9%], p=0.90). Multivariable Cox regression analysis also showed equivalent 2-year survival (adjusted hazard ratio 1.02, 95% CI 0.57-1.84, p=0.95). Transplanting lung allografts that underwent static EVLP at centralized facilities had similar outcomes compared to transplanting lungs perfused at individual transplant centers. The centralized model of clinical EVLP can potentially improve access to EVLP.

Impact of Annual Case Volume on Colorectal Endoscopic Submucosal Dissection Outcomes in a Large Prospective Cohort Study.

The adoption of colorectal endoscopic submucosal dissection (ESD) is still limited in the West. A recent randomized trial showed that ESD is more effective and only slightly riskier than piecemeal endoscopic mucosal resection; reproducibility outside expert centers was questioned. We evaluated the results according to the annual case volume in a multicentric prospective cohort. Between September 2019 and September 2022, colorectal ESD was consecutively performed at 13 participating centers classified as low volume (LV), middle volume (MV), and high volume (HV). The main procedural outcomes were assessed. Multivariate and propensity score matching analyses were performed. Three thousand seven hundred seventy ESDs were included. HV centers treated larger and more often colonic lesions than MV and LV centers. En bloc , R0, and curative resection rates were 95.2%, 87.4%, and 83.2%, respectively, and were higher at HV than at MV and LV centers. HV centers also achieved a faster dissection speed. Delayed bleeding and surgery for complications rates were 5.4% and 0.8%, respectively, without significant differences. The perforation rate (overall: 9%) was higher at MV than at LV and HV centers. Lesion characteristics, but not volume center, were independently associated with both R1 resection and perforation. However, after propensity score matching, R0 rates were significantly higher at HV than at LV centers, and perforation rates were significantly higher at MV than at HV centers. Colorectal ESD can be successfully implemented in the West, even in nonexpert centers. However, difficult lesions must still be referred to experts.

Using machine learning to predict neurologic injury in venovenous extracorporeal membrane oxygenation recipients: An ELSO Registry analysis

BackgroundVenovenous extracorporeal membrane oxygenation (VV-ECMO) is associated with acute brain injury (ABI), including central nervous system (CNS) ischemia (defined as ischemic stroke or hypoxic-ischemic brain injury [HIBI]) and intracranial hemorrhage (ICH). Data on prediction models for neurologic outcomes in VV-ECMO are limited. MethodsWe analyzed adult (age ≥18 years) VV-ECMO patients in the Extracorporeal Life Support Organization (ELSO) Registry (2009-2021) from 676 centers. ABI was defined as CNS ischemia, ICH, brain death, and seizures. Data on 67 variables were extracted, including clinical characteristics and pre-ECMO/on-ECMO variables. Random forest, CatBoost, LightGBM, and XGBoost machine learning (ML) algorithms (10-fold leave-one-out cross-validation) were used to predict ABI. Feature importance scores were used to pinpoint the most important variables for predicting ABI. ResultsOf 37,473 VV-ECMO patients (median age, 48.1 years; 63% male), 2644 (7.1%) experienced ABI, including 610 (2%) with CNS ischemia and 1591 (4%) with ICH. The areas under the receiver operating characteristic curve for predicting ABI, CNS ischemia, and ICH were 0.70, 0.68, and 0.70, respectively. The accuracy, positive predictive value, and negative predictive value for ABI were 85%, 19%, and 95%, respectively. ML identified higher center volume, pre-ECMO cardiac arrest, higher ECMO pump flow, and elevated on-ECMO serum lactate level as the most important risk factors for ABI and its subtypes. ConclusionsThis is the largest study of VV-ECMO patients to use ML to predict ABI reported to date. Performance was suboptimal, likely due to lack of standardization of neuromonitoring/imaging protocols and data granularity in the ELSO Registry. Standardized neurologic monitoring and imaging are needed across ELSO centers to detect the true prevalence of ABI.

The Impact of Donor Body Mass Index on Safety and Outcomes in Living Donor Liver Transplantation: An Analysis of the National United States Database.

The prevalence of obesity is rising in the general population. Donor obesity (body mass index ≥30 kg/m2) may potentially reduce the donor pool and impact outcomes in living donor liver transplantation (LDLT). We utilized the national transplant database to investigate the impact of donor obesity on donor and recipient outcomes. This was a retrospective cohort study of all LDLTs performed in the United States between January 2010 and June 2023. Outcomes of interest were analyzed by univariable and multivariable logistic regression. Patient and graft survival was evaluated using Kaplan-Meier and Cox proportional analysis. Six hundred seventy-four donors with obesity and 3498 donors without obesity were analyzed. Donors with obesity had higher rates of readmission within 1 y of donation (15.9% versus 11.6%; P = 0.003). The risk of readmission was significantly different between 6 wk and 6 mo of donation (8.8% versus 5.9%; P = 0.036). Donor body mass index (odds ratio [OR], 1.460; 95% confidence interval [CI], 1.129-1.999; P = 0.004) and preoperative alkaline phosphatase levels (OR, 1.005; 95% CI, 1.000-1.011; P = 0.038) were independent predictors of donor readmission. High LDLT center volume was associated with reduced odds of donor readmission (OR, 0.509; 95% CI, 0.373-0.694; P < 0.001). Graft and recipient survival was comparable. Selection of living donors with obesity may be a potential avenue to increase the available donor pool without compromising recipient outcomes; however, they are at an increased risk for readmission between 6 wk and 6 mo of donation. The reason for readmission requires further study.

"Long-term effects of center volume on transplant outcomes in adult kidney transplant recipients"

"Long-term effects of center volume on transplant outcomes in adult kidney transplant recipients"

A patient-centered textbook outcome measure effectively discriminates contemporary elective open abdominal aortic aneurysm repair quality

BackgroundThere is persistent controversy surrounding the merit of surgical volume benchmarks being used solely as a sufficient proxy for assessing the quality of open abdominal aortic aneurysm (AAA) repair. Importantly, operative volume quotas may fail to reflect a more nuanced and comprehensive depiction of surgical outcomes most relevant to patients. Accordingly, we herein propose a patient-centered textbook outcome (TO) for AAA repair that is analogous to other large magnitude extirpative operations performed in other surgical specialties, and test its feasibility to discriminate hospital performance using Society for Vascular Surgery (SVS) volume guidelines. MethodsAll elective open infrarenal AAA repairs (OAR) in the SVS-Vascular Quality Initiative were examined (2009-2022). The primary end point was a TO, defined as a composite of no in-hospital complication or reintervention/reoperation, length of stay of ≤10 days, home discharge, and 1-year survival rates. The discriminatory ability of the TO measure was assessed by comparing centers that did or did not meet the SVS annual OAR volume threshold recommendation (high volume ≥10 OARs/year; low volume <10 OARs/year). Logistic regression and multivariable models adjusted for patient and procedure-related differences. ResultsA total of 9657 OARs across 198 centers were analyzed (mean age, 69.5 ± 8.4 years; female, 26%; non-White, 12%). A TO was identified in 44% (n = 4293) of the overall cohort. The incidence of individual TO components included no in-hospital complication (61%), no in-hospital reintervention or reoperation (92%), length of stay of ≤10 days (78%), home discharge (76%), and 1-year survival (91%). Median annual center volume was 6 (interquartile range, 3-10) and a majority of centers did not meet the SVS volume suggested threshold (<10 OARs/year, n = 148 [74%]). However, most patients (6265 of 9657 [65%]) underwent OAR in high-volume hospitals. When comparing high- and low-volume centers, a TO was more likely to occur in high-volume institutions: ≥10 OARs/year (46%) vs <10 OARs/year (42%; P = .0006). The association of a protective effect for higher center volume remained after risk adjustment (odds ratio, 1.1; 95% confidence interval, 1.05-1.26; P = .003). ConclusionsTOs for elective OAR reflect a more nuanced and comprehensive patient centered proxy to measure care delivery, consistent with other surgical specialties. Surprisingly, a TO was achieved in <50% of elective AAA cases nationally. Although the likelihood of a TO seems to correlate with SVS center volume recommendations, it more importantly reflects elements which may be prioritized by patients and thus offers insights into further improving real-world AAA care.