Translesional Assessment of Hemodynamics in Patients Undergoing Endovascular Therapy for Lower Extremity Peripheral Arterial Disease

Introduction. The role of real-time, invasive hemodynamic assessment during endovascular therapy for lower extremity peripheral arterial disease (PAD) has not been well established. The purpose of this study was to examine the feasibility of the Navvus microcatheter coupled to the RXi system (ACIST Medical Systems) to measure lower extremity pre-and post-intervention resting and hyperemic translesional systolic pressure gradients (sTPG) and mean distal to proximal pressure gradients (Pd/Pa). Methods. A total of 22 patients were included with a mean age 63.2 ± 10.1 years. Critical limb ischemia (CLI) was the primary diagnosis in thirteen (59.1%) patients and 9 (39.1%) had claudication. Invasive hemodynamic measurements were obtained using the Navvus microcatheter at baseline and before and after each specific intervention (angioplasty and/or directional atherectomy) without and then with hyperemia using intra-arterial adenosine. Results. The mean baseline non-hyperemic sTPG was 32.0 ± 18.6 mmHg. Hyperemic responses for the sTPG and the Pd/Pa ratio were noted at baseline and post-treatment. Mean sTPG decreased over the course of endovascular treatments (32.0 ± 18.6 to 10.0 ± 11.7 mmHg respectively, P<.001). A hyperemic response was demonstrated for the Pd/Pa, with the ratio decreasing at each time point (P<.01). Both the non-hyperemic and hyperemic Pd/Pa increased after endovascular treatments as compared with each prior baseline (P<.001). Atherectomy alone significantly decreased the sTPGs and increased the Pd/Pa ratio (P<.001). Conclusions. The Navvus microcatheter demonstrated feasibility in measuring changes in lower extremity hemodynamics during endovascular therapy.