Histopathologic studies of the below-the-knee great saphenous vein after endovenous laser ablation.

Background: There has been hesitation to use endovenous laser ablation (EVLA) for the treatment of incompetence of the below-the-knee great saphenous vein (GSV).

Objective: To assess early pathologic changes in the below-the-knee nonvaricose GSV and adjacent tissue after EVLA in legs scheduled for below-the-knee amputation.

Methods: The below-the-knee GSV in five patients was exposed to EVLA using 14-, 12-, and 10-watt laser power with continuous or intermittent laser exposure using a 600-nm core, bare tip fiber. Six segments (3 x 3 cm) of GSV with adjacent tissue were excised, examined histologically, and compared with non-laser-exposed parts of the vessel.

Results: Histologic evaluation revealed thermal damage of the intima and the internal part of the media. At the site of the laser tip, carbonization and necrosis was observed. Vascular perforation with subsequent perivascular bleeding was occasionally (<10%) seen in cases treated with 40 to 80 J/cm and in all cases treated with 110 to 200 J/cm. The saphenous nerve was not damaged.

Conclusion: Based on this histopathologic study, acute thermal damage of the below-the-knee GSV after EVLA was limited to the intima and the inner third of the media. No acute damage of perivascular nerve tissue was observed.