Long-term results of direct and indirect endovascular revascularization based on the angiosome concept in patients with critical limb ischemia presenting with isolated below-the-knee lesions

Objective

We compared clinical outcomes between limbs with and without achievement of feeding artery flow by endovascular therapy (EVT) based on the angiosome concept in critical limb ischemia (CLI) patients with isolated below-the-knee (BTK) lesions and assessed factors influencing major amputation (MA).

Method

We analyzed 369 limbs from 329 consecutive patients (224 men; age, 70 ± 11 years) with ischemic ulceration or gangrene, or both, presenting with isolated BTK lesions (Rutherford class 5, 270 limbs; class 6, 99 limbs) with a pretreatment ankle-brachial index of 0.79 ± 0.26. Patients underwent successful EVT, without bypass surgery. Limbs were classified into direct (n = 200) and indirect (n = 169) groups by whether feeding artery flow to the site of ulceration or gangrene was successfully achieved, based on the angiosome concept. Unadjusted and adjusted (by propensity score matching) between-group rates of amputation-free survival (AFS) and freedom from major amputation (MA) and major adverse limb event (MALE) were compared by Kaplan-Meier analysis and the log-rank test. The independent determinants of MA in the direct and indirect groups were explored by multivariable analysis.

Results

During follow-up (mean, 18 ± 16 months), the overall limb salvage rate was 81% (300 of 369), death occurred in 36% (119 of 329), and the reintervention rate was 31% (114 of 369). After propensity score adjustment, the estimated (± standard error) rates for AFS (49% ± 8% vs 29% ± 6%; P = .0002), freedom from MALE (51% ± 8% vs 28% ± 8%, P = .008), and major amputation (82% ± 5% vs 68% ± 5%, P = .01) were significantly higher in the direct group than in the indirect group for up to 4 years after the index procedure. After multivariable Cox proportional analysis, the independent factors associated with major amputation were hemoglobin A_1c level (hazard ratio [HR], 1.4; 95% confidential interval [CI], 1.1-1.9; P = .006) and cilostazol administration (HR, 0.28; 95% CI, 0.11-0.70; P = .006) in the direct group, and C-reactive protein level (HR, 1.2; 95% CI, 1.1-1.4; P = .002) in the indirect group.

Conclusion

Achieving direct flow by angioplasty based on the angiosome concept in CLI patients with isolated BTK lesions is clinically important for AFS and freedom from MA and MALE. Limb salvage factors appear to differ between patients with and without direct flow from the feeding artery after EVT.