Identifying Vascular Surgery Patients who may Benefit from Upfront Major Amputation versus Ongoing Minor Amputations
Megan E Lombardi, Alexis Betancourt, Sasha A McEwan, Sydney Browder, Jonathan Smith, Michael C Shick, Mark A Farber, Katharine L McGinigle, William A Marston, Luigi Pascarella
University of North Carolina - Chapel Hill, Chapel Hill, NC
Background: Several risk factors including peripheral neuropathy, foot deformity, diabetes, and peripheral vascular disease increase the risk of foot ulceration. Limb preservation versus primary amputation continues to be a debate in terms of quality of life, health care costs, and physical/emotional well-being of patients with foot ulcers. The purpose of our study was to identify specific patients, or characteristics of patients, who may benefit from upfront major amputation rather than distal amputations and to assess 1-year survival following initial operation.
Methods: Retrospective chart review was conducted on patients who underwent minor lower extremity amputation from 2017-2022. Data was collected for one year following the first operation for a lower extremity wound and included demographics, co-morbidities, wound location/size, and WIfI stage. Primary outcomes were 30-day, 6-month, and 1-year risk of major amputation and 1-year risk of all-cause mortality. Generalized estimating equation (GEE) models were used to estimate the crude risk of major amputation at each time-point and risk of amputation over time with the addition of a variety of risk factors while accounting for clustering of individuals with more than 1 qualifying limb. Each risk factor was added to the model individually and a change in estimate was calculated. The threshold for a notable change was ≥20%. Kaplan-Meier models were used to analyze 1-year freedom from major amputation across groups of interest.
Results: The patient cohort included 971 limbs from 858 patients with a mean age of 60.1 years and was 32.5% female and 52.7% white. One year following minor amputation, 11.6% of affected limbs were amputated and 11.5% of patients died. Of the eighteen risk factors analyzed, eight had a change in estimate ≥20% at all three time points (Table 1). A change in estimate of ≥70% were observed across time points for history of stroke (CVA), thrombophilia, end-stage renal disease (ESRD), and revascularization (Table 1). Kaplan-Meyer curves stratified by sex and race/ethnicity showed that non-white women were most likely to undergo a major amputation within a year after minor amputation (log-rank p-value = 0.0024) and curves stratified by PAD diagnosis and revascularization history showed that patients with prior revascularization were more likely to have a subsequent major amputation (log-rank p-value <0.0001).
Conclusions: This study reveals several risk factors, some modifiable and some non-modifiable, that may increase the likelihood a patient will require a major amputation when presenting with a foot wound. History of CVA, thrombophilia, ESRD, and revascularization markedly increased the risk of a major amputation. Additionally, non-white females and patients with a prior revascularization were more likely to progress on to have a major amputation within one year of the initial operation. These risk factors should be considered when counseling patients with foot wounds on prognosis and outcomes following minor amputation.
Table 1. Change in Risk of Amputation with the Addition of a Variety of Covariates
| 30-Day | 6-Months | 1-Year | ||||
| Amputation Risk(95% CI) | Change in risk (%) | Amputation Risk(95% CI) | Change in risk (%) | Amputation Risk(95% CI) | Change in risk (%) | |
| Crude | 0.04(0.03, 0.06) | -- | 0.09(0.07, 0.11) | -- | 0.11(0.09, 0.13) | -- |
| +Sex (Female) | 0.06(0.04, 0.09) | +0.02(45.3%) | 0.09(0.06, 0.13) | +0.0025(2.8%) | 0.11(0.08, 0.15) | +0.0050(4.6%) |
| +Race/Ethnicity (Non-White) | 0.07(0.05, 0.10) | +0.03(69.1%) | 0.12(0.09, 0.16) | +0.04(40.0%) | 0.15(0.11, 0.19) | +0.04(35.2%) |
| +Hx CVA | 0.08(0.04, 0.15) | +0.04(83.8%) | 0.16(0.10, 0.25) | +0.07(79.6%) | 0.19(0.13, 0.28) | +0.09(79.9%) |
| +Hx Diabetes | 0.05(0.03, 0.06) | +0.0027(6.2%) | 0.09(0.07, 0.11) | +0.002(2.3%) | 0.11(0.09, 0.14) | +0.0036(3.3%) |
| +Hx PAD | 0.06(0.04, 0.08) | +0.013(28.9%) | 0.13(0.09, 0.16) | +0.04(43.4%) | 0.16(0.13, 0.19) | +0.05(44.5%) |
| +Hx Thrombophilia | 0.08(0.03, 0.19) | +0.03(74.4%) | 0.19(0.11, 0.32) | +0.10(112.7%) | 0.19(0.11, 0.32) | +0.08(74.4%) |
| +Hx CKD | 0.05(0.03, 0.0874) | +0.0084(19.4%) | 0.11(0.08, 0.16) | +0.02(24.4%) | 0.13(0.09, 0.18) | +0.03(24.3%) |
| +Hx ESRD | 0.09(0.06, 0.15) | +0.05(113.6%) | 0.18(0.13, 0.25) | +0.09(102.0%) | 0.21(0.15, 0.29) | +0.09(92.3%) |
| +Hx Revascularization | 0.09(0.06, 0.13) | +0.04(102.1%) | 0.18(0.14, 0.24) | +0.09(102.0%) | 0.20(0.16, 0.26) | +0.09(84.8%) |
Back to 2024 Posters