Do Collaterals Matter? Comparing the Clinical Outcomes of Direct Revascularization (DR), Indirect Revascularization-With-collateral (IR-tc), and Indirect-without-collateral (IR-wc) in Endovascular Revascularization of Chronic Limb-Threatening Ischemia Patients.

BACKGROUND

Revascularization plays a critical role in chronic limb-threatening ischemia (CLTI) care, aiming to prevent limb loss and improve survival. Revascularization, whether via surgical bypasses or endovascular therapies, plays a major role in saving the limb, prolonging overall patient survival, and improving their quality of life. Our study aims to compare the clinical outcomes of direct revascularization versus indirect revascularization (with or without collaterals) in isolated infrapopliteal percutaneous transluminal angioplasty for the management of CLTI patients with tissue loss.

PATIENTS AND

METHODS

This is a prospective, nonrandomized, comparative clinical study conducted at 2 tertiary centers. The study included all consecutive patients presenting between March 2022 and March 2023 with CLTI due to isolated infrapopliteal arterial occlusive disease or successfully treated proximal femoral lesions with Rutherford stage 5 and 6, and had either critical ischemia/vascularity ankle-brachial index less than 0.4.

RESULTS

One hundred and seventeen patients were assessed for eligibility; 17 patients were excluded from the analysis due to failed revascularization to the ankle (n = 17). The remaining 100 patients with technically successful infrapopliteal endovascular treatment with inline flow to the ankle were included (50 in the DR group and 50 in the IR group) and included in the analysis. Limb salvage, however, was significantly higher in the direct group (98%) than in the indirect group without collaterals (74.1%, P = 0.004). Within the indirect group, patients with collateral supply (IR-tc) had higher limb salvage rates (91.3%) than those without collaterals (IR-wc, 74.1%).

DISCUSSION: The optimal strategy for wound revascularization remains controversial. The angiosome model emphasizes restoring blood flow directly to the tibial artery, which supplies the ulcerated foot region, and several studies have demonstrated improved healing and limb salvage with this approach. Conversely, other reports suggest that wound healing is more strongly influenced by factors such as pedal arch integrity, ulcer location and extent, and patient comorbidities. Recently, increasing focus has been placed on the contribution of collateral circulation to revascularization outcomes. Some studies indicate that indirect revascularization (IR), particularly when supported by collateral vessels (IR-tc), may yield results comparable to direct revascularization (DR).

CONCLUSION

Direct revascularization provides highly effective treatment outcomes in CLTI. In the indirect revascularization group, patients without collateral supply to the ischemic area were associated with the poorest outcomes and a higher risk of limb loss.