Comparative stability of sodium tetradecyl sulphate (STD) and polidocanol foam: impact on vein damage in an in-vitro model.

To compare the half-life of STD and polidocanol air-based foams and the damage they inflict upon human great saphenous vein in an in-vitro model. The time for the volume of 3% STD and polidocanol foams to reduce by 10% (T(90)) and 50% (T(50)) was recorded in an incubator at 37 °C. Segments of proximal GSV harvested during varicose vein surgery were filled with foam for 5 or 15 min. Histological analysis determined percentage endothelial cell loss and depth of media injury. Median (±IQR) T(90) and T(50) for polidocanol were 123.3 s (111.7-165.6) and 266.3 s (245.6-383.1) versus 102.03 s (91.1-112) and 213.13 s (201-231.6) for STD (T(90)p = 0.008, T(50)p = 0.004). Median endothelial loss with polidocanol was; 63.5% (62.2-82.8) and 85.9% (83.8-92.5) versus 86.3% (84.8-93.7) and 97.64% (97.3-97.8) for STD after 5 and 15 min (p = 0.076 and p = 0.009). The median depth and % media thickness injured were 0 μm (0-0 μm) and 0% for both assessments with polidocanol versus 37.4 μm (35.3-45.8 and 43.4 μm (42.1-46.7) and 3.5% (3.1-3.6) and 5.3% (3.7-6.0) after 5 and 15 min for STD (p < 0.01 for all comparisons). Although polidocanol foam shows greater stability than STD foam perhaps remaining in the vein for longer, endothelial cell loss and damage to the media were significantly greater with STD.