Efficacy of Direct Injection in Occlusive Lesion (DIOL) Fashion for Infrapopliteal and Inframalleolar Chronic Total Occlusions.

BACKGROUND

Endovascular therapy (EVT) for chronic total occlusions (CTOs) in patients with critical limb-threatening ischemia (CLTI) remains technically challenging, particularly in infrapopliteal lesions. Direct injection in occlusive lesions (DIOL) fashion is a novel adjunctive strategy that utilizes hydraulic contrast injection through a microcatheter to facilitate guidewire passage by visualizing the vascular pathway. However, its clinical efficacy remains limited.

AIMS: This study aimed to evaluate the periprocedural outcomes of DIOL-assisted EVT for infrapopliteal and inframalleolar CTOs in patients with CLTI.

METHODS

This retrospective, single-center study enrolled 102 patients (102 limbs) with CLTI who underwent DIOL-assisted EVT between October 2018 and 2024. The primary outcome was successful guidewire crossing. Secondary outcomes included technical success, 30-day mortality, major amputation, and target lesion revascularization (TLR).

RESULTS

All target lesions were classified as GLASS stage 4 CTOs, with bilateral calcification in 49% of cases. The mean patient age was 77.0 years; 69% were non-ambulatory, and 23% were on hemodialysis. A total of 76% of patients presented with Rutherford stage 5-6 wounds. DIOL was employed in 91% of infrapopliteal and 22% of inframalleolar lesions. The guidewire crossing and technical success rates were 98% and 95%, respectively. Guidewire perforation occurred in 7% of cases with no major bleeding complications. The 30-day mortality, major amputation, and TLR rates were 5%, 0%, and 11%, respectively.

CONCLUSIONS

DIOL is a useful adjunctive strategy in complex CTOs, potentially facilitating guidewire passage and contributing to procedural success in infrapopliteal and inframalleolar revascularization. Further studies are warranted to validate and standardize its application.