Feasible Evaluation of PQ Bypass Results with Duplex Ultrasound

Patients with peripheral arterial disease (PAD) have substantially impaired health-related quality of life (HR-QoL). Chronic lower limb ischaemia due to the atherosclerotic occlusion of infra-inguinal arteries is one of the most important causes of invalidity among smokers over the age of fifty. Historically, these lesions were treated by open bypass surgery. Less invasive endovascular revascularisation methods are available to treat short lesions, while treatment of long lesions are lacking. Fully endovascular trans-venous femoro-popliteal bypass (PQ Bypass, Inc., Sunnyvale, CA, USA) to treat long femoral lesions has been developed recently. The objective of the study was to evaluate duplex ultrasound (DUS) as a tool to follow up patients after PQ bypass procedure. A prospective clinical study was conducted at one clinical site. DUS of treated arteries and femoral vein was performed before the procedure, 30 days, 6 months, and 12 months in follow-up period by 2 independent radiologists. Ankle-brachial index (ABI) evaluation was performed at all visits. Thirty-five patients (35 limbs) treated with PQ bypass were enrolled in the study. Median age was 63.6 years (ranged 50 to 87 years). There was 100% successful evaluation of all patients at all clinical visits available. Deviation of the DUS results was found within the accepted standard limit between two radiologists. Twelve months after the PQ procedure, 28 (80.0%) PQ stent-grafts were still functioning without DUS signs of stenosis, while seven (20.0%) limbs experienced varying degrees of stent malfunction. PQ stent-graft occlusion was detected in five (14.3%) – 1 (2.9%) patients at one-month follow-up, 3 (8.6%) at six months and 1 (2.9%) at twelve months follow-up period, respectively. PQ stent-graft proximal junction stenosis was detected in one patient (2.9%) at six months and distal junction stenosis in one patient (2.9%) at twelve months follow-up, respectively. Despite of graft occlusion found with DUS, two patients had no severe worsening of post-operative ABI. DUS is a reliable method to evaluate patients after PQ bypass procedure and has higher sensitivity than ABI to follow-up patients after PQ procedure, especially in asymptomatic stent stenosis. Regular and timely use of DUS during the postoperative period may help to recognise potential complications and provide effective treatment..