Comprehensive Limb Evaluation and Arterial Revascularization With Toe Pressure Optimization Registry (CLEAR TOE)

Cricital limb theatening ischemia (CLTI) represents the most advanced stage of peripheral arterial disease (PAD), leading to high mortality rates and limb loss. A primary endovascular strategy is now preferred for most patients with CLTI who have occlusive disease of the tibial arteries. This is especially true for the elderly, diabetic patients, and those without suitable venous conduits for bypass. Patients with CLTI and infra-popliteal occlusive disease do not always respond well to the provided treatment, but the underlying reasons, particularly in those showing good initial results after endovascular revascularization, remain to be determined.

The literature strongly supports the use of drug-eluting stents (DES) in treating infrapopliteal arteries. DES are associated with significant improvements in patency, reduced rates of restenosis and reintervention, and better Rutherford-Becker classification and healing of trophic disorders. However, contrary to initial expectations, the SAVAL trial, whose data were made public in December 2023, comparing a DES dedicated to infra-popliteal arteries with percutaneous transluminal angioplasty in patients with CLTI, failed to meet its primary efficacy (increased primary patency and reduced major adverse events rate) and safety objectives at 12 months, despite preliminary data suggesting an advantage in using DES for treating short lesions. A possible explanation is the significant heterogeneity of practices, with less than half of the patients receiving optimal medical treatment and intensive follow-up, highlighting the need for a comprehensive review of treatment strategies in this challenging patient population.

The lack of an established objective follow-up protocol for this patient group underscores the need for innovative approaches. Currently, there is no widely available consensus indicator to estimate whether the revascularization provided will be sufficient to prevent amputation. The Delta-Perf study has completed its recruitment and is expected to provide results on foot perfusion analysis in patients with CLTI before and after revascularization and its predictive value on amputation-free survival. However, despite high initial technical success rates for endovascular interventions, early failure of these minimally invasive procedures is common.

Current recommendations support duplex scan monitoring and prophylactic reintervention for asymptomatic graft stenosis to promote long-term patency, but monitoring and reintervention strategies after endovascular management have been left to the practitioner's discretion. There are no ongoing studies to determine if the initial improvement observed in the foot is actually maintained, and there is little evidence to support indications for repeated interventions in CLTI. Clinical follow-up alone may be insufficient to detect restenosis, as patients may remain asymptomatic until the target artery is occluded, similar to venous grafts in bypasses. Likewise, measuring the ankle-brachial index (ABI) alone has limited value, given the difficulty in determining the level of restenosis, technical limitations in diabetic patients with calcified vessels, and variability in correlation with the severity of lesions.

It is likely that there are subgroups of patients who could benefit more than others from early reintervention. Toe pressure, in this context, offers a measurable, non-invasive, and clinically relevant parameter that can be consistently evaluated even in challenging cases, particularly in heavily calcified patients.