LAUSR

Critical limb ischemia (CLI) is defined by the presence of chronic ischemic rest pain, ulceration, or gangrene that is attributed to the occlusion of peripheral arterial vessels. A mortality of 20% and 10–40% risk of lower limb amputation has been reported within 6 months of diagnosis of CLI. Revascularization is the first-line treatment for CLI, and endovascular revascularization techniques are becoming the most common initial therapeutic choice. In this issue of Catheterization and Cardiovascular Interventions, Mustapha et al., compared the use of the tibio-pedal arterial minimally invasive (TAMI) retrograde revascularization technique with femoral access approach, or dual access approach (antegrade ipsilateral, or retrograde contralateral femoral combined with retrograde tibio-pedal access) in the treatment of patients with CLI. We congratulate the authors on their retrospective study of prospectively collected data from the PRIME registry, which is the first to compare outcomes of the TAMI technique with the more traditional access approaches. The patients with CLI treated with the TAMI approach had the lowest median fluoroscopy time, procedure time, contrast volume use, hospital stay, and complication rate. A key to successful use of the TAMI technique is having a detailed selective angiographic evaluation of the limb being treated. In the current study, about 55% of TAMI interventions were re-interventions where therefore prior angiographic films were available. A good ultrasound study of the affected limb can also suffice. When an angiographic evaluation is not available, we will use an “assisted TAMI” approach in which we obtain imaging of the affected extremity via access of the ipsilateral radial artery avoiding the potential complications that can occur from a femoral access approach. Becoming proficient in tibio-pedal retrograde access requires some time, especially given the significant disease present in these vessels in CLI patients. We employ visualization of the tibial arteries with an Lshaped “hockey-stick” ultrasound probe with its small field of view, which provides excellent resolution in the near field. The operator should look for the needle and aim for the tibial vessel. Care should be taken to puncture the tibial artery. Each unsuccessful attempt can cause spasm making each subsequent attempt less likely to be successful. Additionally, a tibial vein stick can predispose to access site complications such as arteriovenous fistulas. After tibial artery puncture, one should observe bright red blood return; pulsatile flow is never present. Once access is obtained and wired, we insert a 4 or 5 French sheath. The TAMI technique is feasible because of the low-profile of new endovascular devices. The TAMI approach resulted in the best outcome in this series of patients from the PRIME registry. Randomized trials are needed to further validate this approach to CLI treatment.