Histologic and sonographic features of holmium laser in the treatment of chronic venous disease

Background: A new holmium laser (HOL) has been introduced to the market. The device is able to reduce the great saphenous vein (GSV) caliber in a tumescence-free procedure, favoring an effective sclerotherapy of large vessels. Aim of the present investigation is to provide the first in vivo data about the effect of HOL on GSV histology. Methods: Six chronic venous disease (C2-5, Ep, As, Pr) patients (M:F ratio 1:1; age: 57±8, BMI 24±2 kg/m2) underwent HOL-assisted caliber reduction of the GSV, high-ligation and flush ligation of the incompetent tributaries. Three cm of proximal great saphenous vein not treated by laser and 3 cm of a contiguous segment that was just previously treated by HOL were harvested. Histological assessments were performed. Patent GSV lumen caliber was assessed at the mid-thigh right before, and after the procedure. Periprocedural pain was graded by Visual Analogue Scale. Results: GSV samples after holmium laser therapy showed thickening of the vascular wall with a decreased, yet patent lumen. Immunostaining demonstrated intact endothelial lining in both the treated and not treated segments. Expansion of collagen fibers was observed in the laser-treated segments. Collagen appeared more homogeneous than in controls, with an amorphous appearance. Laser treated veins showed a reduction in elastic fibers with greater fragmentation. Smooth muscle cells appeared swollen. The caliber of the mid-thigh great saphenous vein lumen decreased from 8.1±0.8 mm to 3.9±0.2 mm (P<0.0001). The average periprocedural pain was 1±0.6. Conclusions: HOL significantly reduces the caliber of the GSV. The endothelial lining is spared, while the remaining wall is thickened by a hyalinization-like process.