The impact of angiographic pedal circulation status on wound healing in chronic limb-threatening ischemia after bypass surgery.

Objective: In the treatment of chronic limb-threatening ischemia (CLTI), complete wound healing is an important goal. Although foot perfusion status seems to be important for wound healing, the Global Limb Anatomic Staging System (GLASS) of the Global Vascular Guidelines does not include pedal artery status for the staging process due to the lack of sufficient evidence of its importance. This study aimed to clarify the importance of pedal perfusion status after bypass surgery.

Methods: Among the 153 CLTI cases that underwent bypass distal to popliteal arteries from 2014 to 2018, 117 CLTI limbs with wounds and with sufficient pedal angiographic data were enrolled. They were classified into two groups, based on the wound status 6 months postoperatively; early wound healing group (EWG; n = 78), which achieved complete wound healing within 6 months postoperatively, and prolonged healing or unhealed wounds group (PWG; n = 39), which failed to achieve wound healing within 6 months. Various factors associated with wound healing, including the wound, ischemia, and foot infection (WIfI) classification, intraoperative graft flow, and pedal angiographic data, were analyzed. Regarding pedal angiographic data, in addition to the GLASS inframalleolar/pedal disease descriptor (IPD), newly formed classification system of the pedal circulation status in association with the location of wounds was included: pedal circulation status was classified into two groups as visualized arterial perfusion towards wounds (visualized perfusion) and non-visualized arterial perfusion towards wounds (non-visualized perfusion).

Results: Univariate analysis showed preoperative albumin (Odds ratio [OR], 0.47; 95% confidence interval [CI], 0.24-0.94; P = .027), higher WIfI clinical stage (OR, 3.88; 95% CI, 1.74-10.1; P = .0005), higher IPD (OR, 2.16; 95% CI, 1.16-4.02; P = .012), and non-visualized perfusion to wounds (OR, 5.74: 95% CI, 2.45-14.0; P < .0001) as significant for prolonged wound healing. Multivariate analysis showed higher WIfI stage (OR, 5.04; 95% CI, 1.74-14.6; P = .0029) and non-visualized perfusion to wounds (OR, 4.34; 95% CI, 1.71-11.0; P = .0021) as significant, whereas IPD was not detected as significant. Regarding blood supply to the foot, although graft flow was significantly lower in IPD-P2 than IPD-P0/P1, graft flow was similar regardless of the status of angiographic circulation to wounds, suggesting that distribution of blood supply to the wound would be more important than total amount of blood supply to the foot for wound healing.

Conclusions: WIfI clinical stage and pedal circulatory environment were important factors for wound healing after bypass surgery. Pedal anatomical classification system including perfusion status would be important for decision making in CLTI treatment.