Below-the-Knee Endovascular Therapy for Chronic Limb-Threatening Ischemia

Abstract

Chronic limb-threatening ischaemia (CLTI), the end-stage manifestation of peripheral arterial disease, is associated with a substantial risk of major limb amputation, cardiovascular complications, mortality, and increased healthcare burden. Within this patient population, a distinct subgroup presents with disease confined to the lower leg arteries. This thesis focuses on optimizing endovascular treatment strategies specifically for this subgroup. A central component of this work investigated the prognostic significance of arterial calcification. The Peripheral Arterial Calcium Scoring System (PACSS), traditionally assessed using conventional radiography, was refined for use with computed tomography (CT). This adaptation proved to be a reliable, rapid, and predictive tool for assessing three-month outcomes following endovascular intervention. In the context of arterial calcification, the feasibility and efficacy of a novel endovascular technique, intravascular lithotripsy (IVL), has also been investigated. This method employs acoustic pressure waves to fracture calcified plaques within the vessel wall. Early findings indicate that IVL is a promising adjunctive treatment modality in this patient group. A large registry study, comprising over 1,000 patients undergoing lower leg endovascular therapy, was also conducted, the largest of its kind to date. The results confirmed the overall safety of these procedures but highlighted that outcomes are strongly influenced by procedural success and the clinical severity of CLTI, as quantified by the WIfI (Wound, Ischaemia, and foot Infection) classification system. Finally, the thesis explored optimal post-procedural antithrombotic therapy. A study involving 460 patients compared single antiplatelet therapy (SAPT) and dual antiplatelet therapy (DAPT), revealing no significant difference in clinical outcomes. The ongoing CLEAR-PATH trial is expected to provide more definitive guidance in this area. In summary, this thesis contributes to the refinement of endovascular therapy for lower leg CLTI by promoting more precise patient stratification, introducing innovative treatment techniques, and addressing uncertainties regarding post-interventional medical management.