A retrospective study supports the use of the Wound, ischemia, and foot infection (WIfI) classification system to predict the revascularization benefit for diabetic patients with chronic limb-threatening ischemia (CLTI).
The WIfI classification system was developed to stratify the risk of major amputation at one year for patients presenting with CLTI. Recently, this system was used to identify patients most likely to benefit from revascularization. WIfI scores were used to define the estimated revascularization benefit quartiles ranging from high benefit (Q1) to questionable benefit (Q4).
“The aim of our study was to evaluate the revascularization benefit quartiles in a cohort of diabetic patients who had presented with CLTI,” said first author Caitlin W. Hicks, MD, an associate professor of surgery at Johns Hopkins Hospital, Baltimore, Maryland.
As reported in the October issue of the Journal of Vascular Surgery, researchers from the university’s Diabetic Foot and Wound Service, led by Hicks and senior author Christopher Abularrage, MD, also an associate professor of surgery at Johns Hopkins, evaluated 136 diabetic patients (187 limbs) who underwent lower-extremity revascularization between 2012 and 2020 at their institution. The primary outcome of their study was one-year major amputation.
Revascularization procedures were either endovascular (67%) or open (33%). The estimated one-year amputation rates for each quartile were: 7±4% in Q1, 4±3% in Q2, 7±5% in Q3 and 26±8% in Q4. Analysis revealed the Q4 group had a significantly greater risk of amputation compared with the Q1 group (hazard ratio [HR] 4.3).
For the 137 limbs with greater than one-year follow-up after revascularization, a total of 16 (12%) required amputation. Nine of these were in the Q4 group.
“Overall, our data support the use of the WIfI benefit of revascularization quartiles for estimating the one-year major amputation risk for diabetic patients presenting with CLTI,” said Hicks. “We did, however, observe our actual amputation rate in the Q4 group was one half of what was expected. This may be explained by the fact that all of our diabetic patients are treated by our multidisciplinary team, which has been previously shown to have robust limb salvage outcomes.”
“Up to one half of the Q4 patients who underwent amputation did so despite patency of their revascularization procedure. This suggests wound size and infection burden are the driving factors behind the elevated risk in this group.”
The decision to perform revascularization in a patient with CLTI must be made carefully, particularly given their often extensive list of comorbidities, the researchers said. This study supports the use of the WIfI system to predict which diabetic patients with CLTI might best be served by revascularization and highlights the importance of multidisciplinary teams for complex medical and surgical patients.