IVUS Guidance in BTK Interventions

Chronic limb-threatening ischemia (CLTI) is a severe form of peripheral artery disease in which very poor blood flow in the arteries below the knee can cause rest pain, non-healing wounds, and even loss of the limb. It is often treated with endovascular therapy (EVT), a minimally invasive procedure that opens the blocked artery, but the artery frequently narrows or closes again afterward. These procedures are usually guided by X-ray pictures taken with dye (angiography). Intravascular ultrasound (IVUS) is an imaging tool that uses a small catheter inside the artery to give a more detailed view of the vessel, which may help doctors open it more completely. It is not yet clear whether adding IVUS improves results below the knee. This study is testing whether guiding treatment with IVUS plus angiography keeps the artery open better than angiography alone. Adults aged 18 or older with CLTI who are having endovascular therapy for a blocked artery below the knee may take part. Participants are assigned by chance to be treated with either both imaging methods or angiography alone, and are followed for 12 months. The main question is how well the treated artery stays open at 6 months; researchers will also compare repeat procedures, amputation, complications, wound healing, survival, and quality of life.

Inclusion Criteria: 1. Age ≥18 years. 2. Documented chronic limb-threatening ischemia, meeting the following criteria according to guidelines(13): * Presence of ischemic symptoms compatible with CLTI, defined as arterial insufficiency with gangrene, non-healing ischemic ulcer, or rest pain consistent with Rutherford classes 4-5 AND * Imaging evidence within the past 12 months showing atherosclerotic PAD, including CTA, MRA, angiography or duplex ultrasound AND * Ankle-Brachial Index (ABI) ≤0.80 or Toe-Brachial Index (TBI) ≤0.60 for patients who never underwent revascularization; ABI ≤0.85 or TBI ≤0.65 for those with history of prior revascularization procedures OR * Ischemic rest pain alone (Rutherford class 4) with ankle systolic pressure \