Crossing Atheroma or Thrombus With ByCross Device for Revascularization of Peripheral Arteries of Diameter ≥ 3mm

Occlusive vascular disease (OVD) is the leading cause of mortality and morbidity in the Western world. Arterial obstructions generally start as a build-up of harder atherosclerotic material on which clotted blood (thrombus) forms, whereas veins obstruction contains mostly thrombus. Over 10 million patients in the US suffer from peripheral arterial disease (PAD) including 750,000 critical limb ischemia patients who are at risk of limb amputation.

The existing pharmacological and bypass surgical methods to treat OVD are risky, expensive, and time-consuming. Overcoming these shortcomings presents a substantial opportunity for a mechanical catheter. Atherectomy with mechanical catheters has been used clinically for many years, and by now the clinical outcome of atherectomy is known as reflected by multiple clinical studies. The potential benefit of the technique compared with percutaneous transluminal angioplasty (PTA) and/or Stenting alone or as an adjunctive therapy has also been discussed, and more recently as an adjunctive prior to PTA with a drugeluting balloon and stenting. The existing catheters designed mainly for arteries are expensive, complicated to operate, demonstrate limited reduction in level of stenosis, might cause perforations, distal embolization and hemolysis, have no or poor aspiration, and cannot cross occlusions without passage of guidewire first. Despite the common use of these therapies and current benefits, there remain significant opportunities to extend catheter-based treatments with improved outcomes, to more patients and at lower cost.

The ByCross is a minimal invasive, single use atherectomy and thrombectomy device, which is introduced over the wire into the peripheral vasculature for revascularization of chronic occluded peripheral vessels. The ByCross has a coaxial flexible rotating shaft with an expandable tip and integrates an independent aspiration system for suction of thrombotic material. The expandable tip is an elastic arc that can bow and enlarge the tip diameter from external tip diameter of 1.7mm at closed condition to 4.7mm at open condition. As the shaft rotates, the tip breaks the calcified atheroma or thrombus into small particles, which are simultaneously aspired into the shaft and removed into the attached collection bag. The ByCross allows injection of contrast medium and thrombolytic agents through the rotating tip during the procedure for continuance imaging and prevention of appositional thrombus formation. Due to its no-symmetrical helical design the tip rotation is eccentric, causing the tip to recenter is self within the lumen as it rotates. While ByCross is introduced over a guide wire, it does not require the passage of an occlusion with the wire first. To cross the occlusion the ByCross is advanced with running motor forth and back in a closed condition. Once the occluded segment is crossed the procedure is repeated with open tip at larger diameter vessels to further remove the remaining atheroma or thrombus. The ByCross is battery powered, and includes a remote-control unit which allows the user full ergonomic control of the device next to the puncture site.

Based on compliance with standard requirements, design process and risk analysis process. The risk of occurrence of adverse events is not expected to be greater than the risk reported for other devices available in the market today. More over the past animal test supports the expected low risk. This study, aside to performance investigation, is intended to validate this. The potential significant advantage of the ByCross device in the treatment of chronic limb ischemia is the ability to cross Chronic Total Occlusion (calcified atheroma and/or thrombus, in oppose to other atherectomy devices which can only cross partial occluded vessel due to the necessity of progressing over the wire). Thus, instead of aborting the procedure, completion of revascularization procedure percutaneously is possible. In addition, the ByCross enables, due to its design, to achieve superior patency, injection of contrast medium and antiplatelet during operation of the radio-opaque tip, and enables simultaneous aspiration.

These benefits potentially reduce prolonged percutaneous procedures if other means are required to enable chroni total occlusion (CTO) passage by guidewire, and, might, in the future, reduce the number of bypass surgeries in peripheral arteries, all with no risk compared to long term clinical use of equivalent devices.

Information gathered in this study will further assure the ByCross device as superior solution enabling more beneficial minimal invasive procedure for the subjects with the same indication for treatment.

The study is multi-center, single arm, open label, prospective study. 42 patients with total or subtotal occlusion at target vessel bearing length equal to or larger than 3cm at vessels diameter of 3mm or larger will be enrolled to the study. Eligible consented subjects will undergo a procedure and treated with the ByCross device. Additional adjunctive treatment (such as PTA, stenting etc.) may be performed per physician's discretion and according to standard of care. Assessment of device safety and performance will be performed intra and post procedural, at discharge, at 30 days post procedure and at 6 months. Subjects that will undergo procedure using ByCross only with NO adjunctive therapy will be followed-up at 12 months as well. The overall duration of participation for each subject is expected to be up to 7 months and 13 months for those that undergo procedure using ByCross only.

Primary outcome measures are divided into two: performance and safety. The null hypotheses will be tested via the lower limit of the one-sided 95% exact confidence interval for the respective proportions. The expected Acute Procedural Success rate is 95% as is the rate of subjects free of device-related Major Adverse Events (MAEs) throughout a 30-day follow-up. The sample size required to achieve a lower one-sided 95% exact confidence limit that is greater than 85%, if the point estimate of the proportion is 95%, is calculated as 40 patients. To accommodate a potential 5% drop-out prior to completing 30 days follow-up, up to 42 patients may be required to be enrolled.