SLR - May 2023 - Isaac Wilmot, DPM
Title: Rates of Conversion from Dry to Wet Gangrene Following Lower Extremity RevascularizationReference: Christopher A. Latz, Elizabeth Deluca, Srihari Lella, Harold D. Waller, Charles DeCarlo, Anahita Dua, Rates of Conversion from Dry to Wet Gangrene Following Lower Extremity Revascularization,
Annals of Vascular Surgery, Volume 83, 2022, Pages 20-25
Level of Evidence: Level III Retrospective review of data collected from a tertiary care center
Reviewed By: Isaac Wilmot, DPM
Residency Program: University of Florida College of Medicine - Jacksonville, FL
Podiatric relevance: The association between patients with diabetes and peripheral arterial disease is somewhere between 9% and 55% according to recent literature. As experts in the diabetic foot, it is not uncommon for podiatric physicians to be treating diabetic foot pathologies with concomitant dry gangrene. In patients with suspected or documented vascular insufficiency, podiatric surgeons often require revascularization of a patient’s extremity prior to surgical intervention. Understanding the rate and time frame for conversion from dry to wet gangrene may guide treatment algorithms and prevent adverse outcomes following these revascularizations. This study reviewed 195 patients with lower extremity dry gangrene who underwent revascularizations, assessing the conversion to wet gangrene.
Methods: This was a level III retrospective review looking at data compiled from four Boston hospitals using Partner's Healthcare System's Research Patient Data Registry. Authors identified an initial 1,518 patients with lower extremity dry gangrene (LEDG) that underwent either open, endovascular, or a hybrid revascularization procedures from 2002 to 2020. Inclusion criteria consisted of adults with documented LEDG prior to any revascularization attempt or amputation, ultimately identifying 195 patients that fit the criteria. The study aimed to address the lack of data regarding dry to wet gangrene conversion after revascularization, with a secondary goal of determining mean time from revascularization to conversion.
Results: Of those 195 patients, a total of 15 (7.7%) were noted to have a complete conversion from dry to wet gangrene within the first 30 days following a revascularization procedure. The mean time of conversion for these patients was 13.5 ± 8.6 days. 75 procedures were strictly open revascularizations (38%), 105 were endovascular (53.9%), and 15 were hybrid procedures (7.7%). There was no correlation between the type of intervention and the conversion rate. Of those 15 patients that converted to wet gangrene, each underwent further amputation of the infected digit(s) or further proximal structures.
Conclusions: These revascularization procedures are often necessary prior to podiatric intervention to optimize lower extremity perfusion and subsequent healing potential. This study shows that conversion to wet gangrene typically occurs within the first two weeks following revascularization, indicating that this timeframe is most critical for consistent surveillance of the affected limb(s). These results also show that revascularization may not always be a beneficial therapy for all patients. Amputation or auto-amputation of LEDG may be a safer alternative. This data can help guide follow-up protocols and inpatient monitoring following vascular intervention. Limitations of this study included an ascertainment bias towards patients with previous amputations, lack of sufficient ankle-brachial-index data, and lack of direct causative link between the revascularization procedure and development of gangrene.