Histologic findings after mechanochemical ablation in a caprine model with use of ClariVein

Objective The use of foam and liquid sclerotherapy for the treatment of varicose veins and underlying venous reflux is widespread. A novel device, the ClariVein Occlusion Catheter (Vascular Insights LLC, Madison, Conn), has been the subject of several clinical trials in humans. We report the initial histologic results obtained with use of the device in a caprine vein model.

Methods A total of 11 male goats (12 veins) underwent minimally invasive procedures. Unilateral mechanochemical ablation of the lateral saphenous vein by the ClariVein Occlusion Catheter with an E-140° tip was performed under fluoroscopic guidance in five veins with 5 mL of 1.5% sodium tetradecyl sulfate (STS) and in one vein with 5 mL of 0.9% saline. The remaining six received injection sclerotherapy with 5 mL of 1.5% STS or 0.9% saline. All subjects were assessed with ultrasound before the procedure and intermittently afterward during a period of 12 weeks. Subsequent termination was immediately followed by necropsy and histologic examination of the treated veins.

Results Complete occlusion of the lateral saphenous vein was observed in all subjects treated with ClariVein and STS, whereas complete patency was noted in all other treatment modalities. Histologic staining with hematoxylin and eosin and Masson trichrome stain revealed total fibrotic sealing with extensive collagen production in all ClariVein/STS veins. A statistical significance was observed in the difference in the number of occluded veins between subjects treated with ClariVein/STS and those treated by injection sclerotherapy (Fisher exact test, P <.01).

Conclusions The ClariVein Occlusion Catheter with 1.5% STS can be used to achieve complete mechanochemical ablation of the lateral saphenous vein in a caprine model. The evidence in this report can be used to justify the device's use for the treatment of the great saphenous vein in subsequent human clinical trials.