Angiography is an Important Adjunct to WIfI Clinical Staging

The SVS Threatened Limb Classification System (“WIfI”) is used to predict risk of limb loss and potentially predict benefit of revascularization in the setting of chronic limb-threatening ischemia (CLTI). We sought to analyze angiographic findings by WIfI classification in patients with CLTI. We performed a single-center retrospective review of 100 consecutive patients in 2020 who underwent angiography for gangrene or nonhealing foot ulcers. WIfI clinical stages were determined for each patient. Toe, ankle, and brachial pressure measurements were performed by registered vascular technologists. Angiograms were characterized by board-certified vascular surgeons using the Global Limb Anatomic Staging System (GLASS) and presence of in-line flow to relevant angiosome(s). Hemodynamically significant disease pertaining to in-line flow to the foot and angiosome, as seen on angiography, was documented. Descriptive statistics were used for analysis. A total of 100 limbs were identified and classified by WIfI clinical stage as follows: 16 stage 1, 19 stage 2, 29 stage 3, and 31 stage 4. Five patients did not have available noninvasive hemodynamic studies and were staged based on their wound and foot infection stage (three at least 1 and two at least 3). Only 11 of 35 patients (31%) categorized as WIfI stage 1 or 2 had in-line flow to the affected angiosome. Among WIfI stage 3 and 4 limbs, only 9 (15%) had in-line flow to the affected angiosome. Thirteen of 26 patients (50%) with WIfI ischemia grade 0 did not have in-line flow to the affected angiosome, including 8 patients who had GLASS II or III disease. Twenty-three of 27 patients (85.2%) with WIfI ischemia grade 1 did not have in-line flow to the affected angiosome, including 14 patients (51.2% of ischemia grade 1) who had GLASS II or III disease. In sum, the addition of angiography identified potential understaging in 36 of 53 patients (67.9%). In the 15 patients with a moderate to high risk of amputation (WIfI stages 3 and 4) but with very low to low revascularization benefit (ischemia grades 0 and 1), angiography identified 10 (66.6%) patients who could potentially benefit from revascularization based on lack of in-line flow to the angiosome. The Society for Vascular Surgery Threatened Limb Classification System identifies most patients with CLTI. Angiography based on overall clinical judgment identifies peripheral artery disease in many patients across the entire WIfI spectrum, reinforcing the global guidelines' recommendation to restage and consider angiography in patients who fail to improve after 1 month of optimal foot care.