Fig. 4.

(a) Photograph of the excised canine jugular vein. (b) Photograph of the thermal lesion formed in the inner wall of the vein (tunica intima). Black dashed circle indicates the ablated area. (c) Changes in the PA amplitude due to temperature changes, when the ablation catheter is placed inside an excised vein tissue. The trough in the graph indicates the drop in the PA amplitude and the formation of the thermal lesion which leads to the closure of the vein. Histology images of the (d) non-ablated (healthy) vein, dashed rectangular region magnified to indicate different layers of the vein and (e) ablated vein, dashed rectangular region indicates the coagulative necrosis of the muscle fibers in the tunica media layer of the vein. Black arrows indicate the damaged regions within the vein.