Editor's Choice - Optimal Threshold for the Volume-Outcome Relationship After Open AAA Repair in the Endovascular Era: Analysis of the International Consortium of Vascular Registries

TY - JOUR

T1 - Editor's Choice - Optimal Threshold for the Volume-Outcome Relationship After Open AAA Repair in the Endovascular Era: Analysis of the International Consortium of Vascular Registries

AU - Scali, Salvatore T

AU - Beck, Adam

AU - Sedrakyan, Art

AU - Mao, Jialin

AU - Behrendt, Christian-Alexander

AU - Boyle, Jonathan R

AU - Venermo, Maarit

AU - Faizer, Rumi

AU - Schermerhorn, Marc

AU - Beiles, Barry

AU - Szeberin, Zoltan

AU - Eldrup, Nikolaj

AU - Thomson, Ian

AU - Cassar, Kevin

AU - Altreuther, Martin

AU - Debus, Sebastian

AU - Johal, Amundeep

AU - Bjorck, Martin

AU - Cronenwett, Jack L

AU - Mani, Kevin

N1 - Copyright © 2021 European Society for Vascular Surgery. Published by Elsevier B.V. All rights reserved.

PY - 2021/5/1

Y1 - 2021/5/1

N2 - OBJECTIVE: As open abdominal aortic aneurysm (AAA) repair (OAR) rates decline in the endovascular era, the endorsement of minimum volume thresholds for OAR is increasingly controversial, as this may affect credentialing and training. The purpose of this analysis was to identify an optimal centre volume threshold that is associated with the most significant mortality reduction after OAR, and to determine how this reflects contemporary practice.METHODS: This was an observational study of OARs performed in 11 countries (2010 - 2016) within the International Consortium of Vascular Registry database (n = 178 302). The primary endpoint was post-operative in hospital mortality. Two different methodologies (area under the receiving operating curve optimisation and Markov chain Monte Carlo procedure) were used to determine the optimal centre volume threshold associated with the most significant mortality improvement.RESULTS: In total, 154 912 (86.9%) intact and 23 390 (13.1%) ruptured AAAs were analysed. The majority (63.1%; n = 112 557) underwent endovascular repair (EVAR) (OAR 36.9%; n = 65 745). A significant inverse relationship between increasing centre volume and lower peri-operative mortality after intact and ruptured OAR was evident (p < .001) but not with EVAR. An annual centre volume of between 13 and 16 procedures per year was associated with the most significant mortality reduction after intact OAR (adjusted predicted mortality < 13 procedures/year 4.6% [95% confidence interval 4.0% - 5.2%] vs. ≥ 13 procedures/year 3.1% [95% CI 2.8% - 3.5%]). With the increasing adoption of EVAR, the mean number of OARs per centre (intact + ruptured) decreased significantly (2010 - 2013 = 35.7; 2014 - 2016 = 29.8; p < .001). Only 23% of centres (n = 240/1 065) met the ≥ 13 procedures/year volume threshold, with significant variation between nations (Germany 11%; Denmark 100%).CONCLUSION: An annual centre volume of 13 - 16 OARs per year is the optimal threshold associated with the greatest mortality risk reduction after treatment of intact AAA. However, in the current endovascular era, achieving this threshold requires significant re-organisation of OAR practice delivery in many countries, and would affect provision of non-elective aortic services. Low volume centres continuing to offer OAR should aim to achieve mortality results equivalent to the high volume institution benchmark, using validated data from quality registries to track outcomes.

AB - OBJECTIVE: As open abdominal aortic aneurysm (AAA) repair (OAR) rates decline in the endovascular era, the endorsement of minimum volume thresholds for OAR is increasingly controversial, as this may affect credentialing and training. The purpose of this analysis was to identify an optimal centre volume threshold that is associated with the most significant mortality reduction after OAR, and to determine how this reflects contemporary practice.METHODS: This was an observational study of OARs performed in 11 countries (2010 - 2016) within the International Consortium of Vascular Registry database (n = 178 302). The primary endpoint was post-operative in hospital mortality. Two different methodologies (area under the receiving operating curve optimisation and Markov chain Monte Carlo procedure) were used to determine the optimal centre volume threshold associated with the most significant mortality improvement.RESULTS: In total, 154 912 (86.9%) intact and 23 390 (13.1%) ruptured AAAs were analysed. The majority (63.1%; n = 112 557) underwent endovascular repair (EVAR) (OAR 36.9%; n = 65 745). A significant inverse relationship between increasing centre volume and lower peri-operative mortality after intact and ruptured OAR was evident (p < .001) but not with EVAR. An annual centre volume of between 13 and 16 procedures per year was associated with the most significant mortality reduction after intact OAR (adjusted predicted mortality < 13 procedures/year 4.6% [95% confidence interval 4.0% - 5.2%] vs. ≥ 13 procedures/year 3.1% [95% CI 2.8% - 3.5%]). With the increasing adoption of EVAR, the mean number of OARs per centre (intact + ruptured) decreased significantly (2010 - 2013 = 35.7; 2014 - 2016 = 29.8; p < .001). Only 23% of centres (n = 240/1 065) met the ≥ 13 procedures/year volume threshold, with significant variation between nations (Germany 11%; Denmark 100%).CONCLUSION: An annual centre volume of 13 - 16 OARs per year is the optimal threshold associated with the greatest mortality risk reduction after treatment of intact AAA. However, in the current endovascular era, achieving this threshold requires significant re-organisation of OAR practice delivery in many countries, and would affect provision of non-elective aortic services. Low volume centres continuing to offer OAR should aim to achieve mortality results equivalent to the high volume institution benchmark, using validated data from quality registries to track outcomes.

KW - Aged

KW - Aged, 80 and over

KW - Aortic Aneurysm, Abdominal/mortality

KW - Benchmarking/standards

KW - Female

KW - Hospital Mortality

KW - Hospitals, High-Volume/standards

KW - Hospitals, Low-Volume/organization & administration

KW - Humans

KW - Internationality

KW - Male

KW - Middle Aged

KW - Outcome Assessment, Health Care/standards

KW - Postoperative Complications/epidemiology

KW - Prospective Studies

KW - Reference Values

KW - Registries/statistics & numerical data

KW - Vascular Surgical Procedures/adverse effects

U2 - 10.1016/j.ejvs.2021.02.018

DO - 10.1016/j.ejvs.2021.02.018

M3 - SCORING: Journal article

C2 - 33722485

VL - 61

SP - 747

EP - 755

JO - EUR J VASC ENDOVASC

JF - EUR J VASC ENDOVASC

SN - 1078-5884

IS - 5

ER -