Chronic Wound Mediated Lower Extremity Amputations and Untimely Mortality: A Systematic Review and Meta-analysis

Background: The pathway from chronic wound to major lower extremity amputation is extensively documented and known to have immense consequences on quality of life. However, mortality rates after lower extremity amputation for chronic wounds remain broad in literature and have escaped precise definition. This systematic review aims to quantify long-term mortality after major lower extremity amputation in the chronic wound population available in the existing literature.

Methods: Ovid MEDLINE was searched for publications providing mortality data after major, nontraumatic, wound-associated primary lower extremity amputations.  Lower extremity amputations were defined as below and above the knee amputation.  Meta-analysis was conducted assuming a random-effects model and analyzed to obtain 1-, 2-, 3-, 5- and 10-year mortality rates.

Results: Sixty-one studies satisfied inclusion representing 36,037 patients across 17 countries. Pooled mortality rates were 33.7%, 51.5%, 53%, 64.4%, and 80%  at 1-, 2-, 3-, 5- and 10-year follow-up, respectively. Within the 8,184 diabetic patients (types 1 and 2), 1- and 5-year mortality was 27.3% and 63.2%. Patients with diabetes as a clinical factor carried a relative mortality risk of 1.24 and 1.35 (P < 0.0001, CI 95%) at 1 and 5 years after amputation, respectively. 10,344 above-knee amputations and 11,320 below-knee amputations constituted sub-population analysis, and above-knee amputations only trended towards higher mortality at 1, 2 and 5 years (P = .08) with mortality rates of 44%, 59.5% and 69.8%, respectively, as compared to 35%, 41.8% and 56.6% amongst patients with below-knee amputations at the same periods. Sources of mortality data varied and included electronic medical records, national health and insurance registries, and government databases.

Conclusion: This meta-analysis with a robust population provides the most updated assessment of long-term mortality after wound associated nontraumatic major lower extremity amputation. Mortality after nontraumatic major lower extremity amputation is high, both in patients with diabetes as well as those without. Methods used to measure and report mortality are inconsistent and may underestimate true mortality rates. These findings illustrate the need for a paradigm shift in wound management and improved outcomes reporting. A focus on amputation prevention and care within a multidisciplinary team is critical for recalcitrant ulcers.