Risk Factors for Lower Extremity Minor Amputation Conversion to Major Amputation

Nicholas P Rolle; Qingwen Kawaji; Claire Morton; Kenneth M Rosenberg; Richa Kalsi; David N Blitzer; Khanjan Nagarsheth

doi:10.1016/j.avsg.2023.12.066

Risk Factors for Lower Extremity Minor Amputation Conversion to Major Amputation

Ann Vasc Surg. 2024 Feb 20:104:166-173. doi: 10.1016/j.avsg.2023.12.066. Online ahead of print.

Authors

Nicholas P Rolle¹, Qingwen Kawaji², Claire Morton³, Kenneth M Rosenberg⁴, Richa Kalsi⁴, David N Blitzer⁵, Khanjan Nagarsheth⁵

Affiliations

¹ Department of Surgery, Inova Fairfax Medical Campus, Falls Church, VA. Electronic address: Nrolle21md@gmail.com.
² Department of Surgery, Medstar Health Baltimore, Baltimore, MD.
³ Department of Surgery, Yale School of Medicine, New Haven, CT.
⁴ Department of Surgery, University of Maryland Medical Center, Baltimore, MD.
⁵ Division of Vascular Surgery, Department of Surgery, University of Maryland Medical Center, Baltimore, MD.

PMID: 38387800
DOI: 10.1016/j.avsg.2023.12.066

Abstract

Background: Minor lower extremity amputations (LEAs) have become an important part of the limb salvage approach but are not as benign as previously thought. This study investigates the difference in outcome between toe/ray versus midfoot amputations and the risk factors for major amputation conversion associated with each procedure.

Methods: We performed retrospective chart review of foot amputation patients at a single tertiary care medical center with a primary end point of conversion to major amputation and secondary end points of 1-year wound healing and mortality rate. We collected data on relevant medical comorbidities, noninvasive vascular imaging, revascularization, repeat amputations, wound healing rate, and 1-year mortality. Patients were separated into toe/ray amputations versus midfoot amputation groups and compared using descriptive statistics, Chi-squared tests, Cox proportional hazards, and a multivariate logistic regression model.

Results: A total of 375 amputations were included in the analysis. 65.3% (245 patients) included toe/ray amputations and 34.7% (130 patients) included midfoot amputations. We compared these 2 cohorts with regard to their rate of conversion to repeat minor and/or major amputation in addition to overall mortality. The toe/ray group underwent more repeat minor amputations within 1 year after index amputation (34.7% vs. 21.5%, P = 0.008) and wound healing (epithelization) at 90 days was also higher in this group. The midfoot group had a higher conversion to major LEA within 1 year on univariate analysis (20.8 vs. 6.9%, P < 0.001). Overall 1-year mortality was 6.17% and there was no significant difference between groups.

Conclusions: While there is a consistency with previous studies that found no significant overall difference in mortality between types of minor LEA, we have extended this previous work by demonstrating the independent risk factors for conversion to major amputation between types of minor LEA. Comparing these 2 groups will assist surgeons in choosing the appropriate level of amputations and will enhance patient's understanding of their chance of wound healing and risk of repeat amputation.