Peripheral Artery Disease Leading to Major Amputation: Trends in Revascularization and Mortality Over 18 Years

Abstract

Patients with peripheral artery disease (PAD) are at risk for amputation. The aim of this study was to assess the type of revascularization prior to and the 30-day mortality rate after major amputation due to PAD. Retrospective analysis of consecutive patients undergoing major amputation for PAD between 01/2000 and 12/2017 at a tertiary referral center. The number and target level of ipsilateral revascularizations prior to amputation were analyzed per patient and over the years. There were 3 types of revascularization (open, endovascular and combined treatment) at 3 levels: aortoiliac, femoropopliteal and infrapopliteal. Univariate and multivariate logistic regression models were used to assess the association of level of amputation and patient characteristics with 30-day mortality. A total of 312 patients (65.7% male) with a mean age of 73.3 ± 11 years underwent 338 major amputations: 70 (21%) above/through knee and 268 (79%) below knee. A median of 2 (interquartile range, IQR 1-4) revascularizations were performed prior to amputation, with a slight decrease of 1.4% per year from 2000-2017 (incidence rate ratio of 0.986 0.974-0.998; Poisson regression analysis, P=0.021). 16% (53/338) of patients underwent primary amputation without revascularization; this number remained relatively stable throughout the study period. The proportion of exclusively open treatment before amputation decreased substantially from 35% in 2006 to none in 2016, while exclusively endovascular revascularizations were performed increasingly from 17% in 2002 to 64% in 2016. Amputation occurred after a median of 9.5 months (IQR 0.9-67.6 months) if the first revascularization was aortoiliac or femoropopliteal and after 2.1 months (IQR 0.5-13.8 months) if the first intervention was infrapopliteal (P < 0.001) with no significant change over the years (normal linear regression, P= 0.887). Thirty-day mortality was 8.9% (22/247) after below knee and 27.7% (18/65) after above/through knee amputation (adjusted OR 3.84, 95% CI 1.74-8.54, P= 0.001) with a slight increase of mortality over the study period (adjusted OR 1.09, 95% CI 1.018-1.159, Poisson regression analysis, P= 0.021). The uni- and multivariate analysis of patient characteristics did not show an association with mortality, except higher ASA classification (adjusted OR 2.65, 95% CI 1.23-5.72, P= 0.012). Mortality, especially after above/through knee amputation, remains high over the past 2 decades. There is a clear shift towards endovascular treatment of patients with PAD prior to major amputation. In patients needing infrapopliteal revascularizations, amputation was performed much sooner than in those with aortoiliac or femoropopliteal interventions, with no improvement over the years. Strategies to extend limb salvage in these patients should be the focus of further research.