The Impact of Centralisation and Endovascular Aneurysm Repair on Treatment of Ruptured Abdominal Aortic Aneurysms Based on International Registries

Objectives

Current management of ruptured abdominal aortic aneurysms (RAAA) varies among centres and countries, particularly in the degree of implementation of endovascular aneurysm repair (EVAR) and levels of vascular surgery centralisation. This study assesses these variations and the impact they have on outcomes.

Materials and methods

RAAA repairs from vascular surgical registries in 11 countries, 2010–2013, were investigated. Data were analysed overall, per country, per treatment modality (EVAR or open aortic repair [OAR]), centre volume (quintiles I V), and whether centres were predominantly EVAR (≥50% of RAAA performed with EVAR [EVAR(p)]) or predominantly OAR [OAR(p)]. Primary outcome was peri-operative mortality. Data are presented as either mean values or percentages with 95% CI within parentheses, and compared with chi-square tests, as well as with adjusted OR.

Results

There were 9273 patients included. Mean age was 74.7 (74.5–74.9) years, and 82.7% of patients were men (81.9–83.6). Mean AAA diameter at rupture was 7.6 cm (7.5–7.6). Of these aneurysms, 10.7% (10.0–11.4) were less than 5.5 cm. EVAR was performed in 23.1% (22.3–24.0). There were 6817 procedures performed in OAR(p) centres and 1217 performed in EVAR(p) centres. Overall peri-operative mortality was 28.8% (27.9–29.8). Peri-operative mortality for OAR was 32.1% (31.0–33.2) and for EVAR 17.9% (16.3–19.6), p < .001, and the adjusted OR was 0.38 (0.31–0.47), p < .001. The peri-operative mortality was 23.0% in EVAR(p) centres (20.6–25.4), 29.7% in OAR(p) centres (28.6–30.8), p < .001; adjusted OR = 0.60 (0.46–0.78), p < .001. Peri-operative mortality was lower in the highest volume centres (QI > 22 repairs per year), 23.3% (21.2–25.4) than in QII-V, 30.0% (28.9–31.1), p < .001. Peri-operative mortality after OAR was lower in high volume centres compared with the other centres, 25.3% (23.0–27.6) and 34.0% (32.7–35.4), respectively, p < .001. There was no significant difference in peri-operative mortality after EVAR between centres based on volume.

Conclusions

Peri-operative mortality is lower in centres with a primary EVAR approach or with high case volume. Most repairs, however, are still performed in low volume centres and in centres with a primary OAR strategy. Reorganisation of acute vascular surgical services may improve outcomes of RAAA repair.

Link: http://www.ejves.com/article/S1078-5884(18)30050-9/fulltext

 

Variations in Abdominal Aortic Aneurysm Care: A Report From the International Consortium of Vascular Registries

BACKGROUND:

This project by the ICVR (International Consortium of Vascular Registries), a collaboration of 11 vascular surgical quality registries, was designed to evaluate international variation in the contemporary management of abdominal aortic aneurysm (AAA) with relation to recommended treatment guidelines from the Society for Vascular Surgery and the European Society for Vascular Surgery.

METHODS:

Registry data for open and endovascular AAA repair (EVAR) during 2010 to 2013 were collected from 11 countries. Variations in patient selection and treatment were compared across countries and across centers within countries.

RESULTS:

Among 51 153 patients, 86% were treated for intact AAA (iAAA) and 14% for ruptured AAA. Women constituted 18% of the entire cohort (range, 12% in Switzerland-21% in the United States; P<0.01). Intact AAAs were repaired at diameters smaller than recommended by guidelines in 31% of men (<5.5 cm; range, 6% in Iceland-41% in Germany; P<0.01) and 12% of women with iAAA (<5 cm; range, 0% in Iceland-16% in the United States; P<0.01). Overall, use of EVAR for iAAA varied from 28% in Hungary to 79% in the United States (P<0.01) and for ruptured AAA from 5% in Denmark to 52% in the United States (P<0.01). In addition to the between-country variations, significant variations were present between centers in each country in terms of EVAR use and rate of small AAA repair. Countries that more frequently treated small AAAs tended to use EVAR more frequently (trend: correlation coefficient, 0.51; P=0.14). Octogenarians made up 23% of all patients, ranging from 12% in Hungary to 29% in Australia (P<0.01). In countries with a fee-for-service reimbursement system (Australia, Germany, Switzerland, and the United States), the proportions of small AAA (33%) and octogenarians undergoing iAAA repair (25%) were higher compared with countries with a population-based reimbursement model (small AAA repair, 16%; octogenarians, 18%; P<0.01). In general, center-level variation within countries in the management of AAA was as important as variation between countries.

CONCLUSIONS:

Despite homogeneous guidelines from professional societies, significant variation exists in the management of AAA, most notably for iAAA diameter at repair, use of EVAR, and the treatment of elderly patients. ICVR provides an opportunity to study treatment variation across countries and to encourage optimal practice by sharing these results.

Link: https://www.ncbi.nlm.nih.gov/pubmed/27784712

Regional Differences in Case Mix and Peri-operative Outcome After Elective Abdominal Aortic Aneurysm Repair in the Vascunet Database

OBJECTIVE/BACKGROUND:

National differences exist in the outcome of elective abdominal aortic aneurysm (AAA) repair. The role of case mix variation was assessed based on an international vascular registry collaboration.

METHODS:

All elective AAA repairs with aneurysm size data in the Vascunet database in the period 2005-09 were included. AAA size and peri-operative outcome (crude and age adjusted mortality) were analysed overall and in risk cohorts, as well as per country. Glasgow Aneurysm Score (GAS) was calculated as risk score, and patients were stratified in three equal sized risk cohorts based on GAS. Predictors of peri-operative mortality were analysed with multiple regression. Missing data were handled with multiple imputation.

RESULTS:

Patients from Australia, Finland, Hungary, Norway, Sweden and the UK (n = 5,895) were analysed; mean age was 72.7 years and 54% had endovascular repair (EVAR). There were significant variations in GAS (lowest = Finland [75.7], highest = UK [79.4], p for comparison of all regions < .001), proportion of AAA < 5.5 cm (lowest = UK [6.4%], highest = Hungary [29.0%]; p < .001), proportion undergoing EVAR (lowest = Finland [10.1%], highest = Australia [58.9%]; p < .001), crude mortality (lowest = Norway [2.0%], highest = Finland [5.0%]; p = .006), and age adjusted mortality (lowest = Norway [2.5%], highest = Finland [6.0%]; p = .048). Both aneurysm size and peri-operative mortality were highest among patients with a GAS >82. Of those with a GAS >82, 8.4% of men and 20.8% of women had an AAA <5.5 cm.

CONCLUSION:

Important regional differences exist in case selection for elective AAA repair, including variations in AAA size and patient risk profile. These differences partly explain the variations in peri-operative mortality. Further audit is warranted to assess the underlying reasons for the regional variation in case-mix.

Link: https://www.ncbi.nlm.nih.gov/pubmed/25752419