The Relationship between Hospital or Surgeon Volume and Outcomes in Lower Limb Vascular Surgery in the United Kingdom and Europe

Background: Peripheral vascular disease is a major cause of death and disability. The extent to which volume influences outcome of lower limb (LL) vascular surgery remains unclear. This review evaluated the relationship between hospital/surgeon volume and outcome in LL surgery.

Methods: Electronic databases-MEDLINE, Embase, the Cochrane Library Databases, Science Citation Index, and CINAHL-proceedings from conferences, citations, and references of included studies were searched. Studies from Europe, of adults undergoing LL vascular surgery reporting outcomes by hospital or surgeon volume were included. The quality of studies was assessed using a modified Cochrane Risk Of Bias Assessment Tool: for Non-Randomized Studies of Interventions (Robins1) tool. The association between hospital/surgeon volume and outcome was summarized using tables.

Results: Nine studies from different European countries, comprising 67,445 patients who had undergone diverse LL surgeries were included. The increase in hospital/surgeon volume was associated with a decrease in post-operative amputations (hospital at 30 days [odds ratio {OR}: 0.20, 95% confidence interval {CI} 0.29-0.45, P = 0.01; OR: 0.67, 95% CI 0.44-0.9, P = 0.05; OR: 0.96, 95% CI 0.92-1.00, P = 0.06], at 1 year [OR: 0.96, 95% CI 0.93-0.98, P = 0.002; OR: 0.66, 95% CI 0.52-0.84, P < 0.001; OR: 2.05, 95% CI 1.24-3.42, P = 0.01], surgeon at 30 days [OR: 0.53, 95% CI 0.36-0.87, P = 0.01; OR: 0.40, 95% CI 0.18-0.91, P = 0.03; OR: 0.41, 95% CI 0.24-0.69, P = 0.0006]). The evidence on an association between hospital/surgeon volume and mortality was contradictory, but mortality and amputations may covary by hospital volume. There were an insufficient number of studies reporting on the other variables to draw firm conclusions, but their results suggest that high-volume hospitals may undertake more repeated surgeries/revascularizations and limb salvage. The impact of hospital/surgical volume on adverse events and length of hospitalization could not be determined.

Conclusions: High-volume hospitals/surgeons may undertake fewer amputations and mortality and amputations may covary. The finding that hospital and surgeon volume affected the number of secondary amputations has implications on reorganization of vascular surgery services. However, due to the small number and poor quality of some of the included studies, decisions on reorganization of LL vascular surgery services should be supplemented by results from clinical audits. There is need for standardization of definition of volume stratification of outcomes by patient's clinical conditions.