SLR - August 2020 - Jason C. Wright

Rates and Timing of Subsequent Amputation After Initial Minor Amputation

Reference: Lin JH, Jeon SY, Romano PS, Humphries MD. Rates and Timing of Subsequent Amputation After Initial Minor Amputation. J Vasc Surg. 2020;72(1):268-275.

Scientific Literature Review

Reviewed By: Jason C. Wright, DPM
Residency Program: Beaumont Hospital – Farmington Hills, MI

Podiatric Relevance: Podiatric physicians treat wounds of the lower extremity and routinely perform minor amputations. In order to provide quality care podiatrists will often work closely with a vascular surgery team when treating these wounds. Unfortunately, a portion of these patients go on to have further amputation including below-knee amputations. Understanding potential risk factors for further amputation is vital for improving patient outcomes following minor amputations. Lit et al attempt to identify risk factors for undergoing a subsequent amputation following a minor amputation. 

Methods: The authors utilized the California OSHPD database to retrospectively evaluate patients with minor lower extremity amputations (digital amputation and TMA). This database pulls data from all non-federal inpatient hospitals, emergency departments and ambulatory surgery centers. Patients are identified by a unique number and includes diagnostic codes and procedure codes for each visit. Using the database they were able to evaluate a total of 11,597 patients with a minor amputation of the lower extremity from 2005-2013. The patients were divided into three groups. The first group consisted of  patients with PAD. The second group was patients with DM. The final group included patients with both PAD and DM. The evaluators used major amputation (BKA or AKA) as the primary endpoint. Secondary endpoints included subsequent minor amputation, time to amputation and mortality.

Results: Out of the 11,597 patients identified that had undergone a minor amputation 5.1 percent went on to a major amputation and 14.5 percent went on to a subsequent minor amputation. Average time to amputation was 12.9 months for major amputations and 4.9 minor amputations. Patients with both PAD and DM had a significantly higher risk of major amputation compared to other groups. All three groups had a high mortality rate. Patients with PAD had the quickest time to death of 10 years. 

Sixty-three percent of patients undergoing a major amputation did not undergo a revascularization procedure prior to major amputation. Timing of revascularization played a role in the rate of major amputation. Patient who underwent revascularization prior to a second minor amputation were significantly less likely to have a major amputation compared to those who had a revascularization procedure after a second minor amputation. Lastly, patients that were treated on a completely outpatient basis were significantly less likely to undergo a major amputation compared to patients who were admitted or treated the emergency department. 

Conclusions: The authors concluded that patients with PAD and DM were the most at risk for undergoing a major amputation. They recommend that these patients receive evaluation and possible intervention by a vascular doctor while receiving care. They also demonstrate that a large portion of patients do not receive revascularization prior to a major amputation. They concluded that patients with lower extremity wounds and comorbidities, especially those with both PAD and DM should be considered for revascularization when indicated. 

This study highlights the effect of comorbidities on the rate of major amputation. It is important for the podiatric community to understand these risk factors and provide timely referrals to vascular surgeons for these patients. 

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