Intraluminal fibre-tip centring can improve endovenous laser ablation: a histological study

In this histological study, the lateral saphenous vein of the goat was treated using a laser fibre to which a tulip-shaped, self-expandable catheter had been fixed to achieve endovenous laser ablation (EVLA). The catheter centres the laser fibre in the vein preventing direct contact with the vein wall. This study aims to establish whether prevention of direct contact between the fibre tip and the vein wall prevents ulceration and perforation of the vein wall and perivenous tissue destruction.

Ten lateral saphenous veins were treated, using the tulip catheter, in goats under general anaesthesia. Ten more veins were treated with a normal bare fibre. We used a 980 nm diode laser to provide the energy. Postoperatively the veins were removed immediately, at 10 days and after 3 weeks for histological examination. Destruction of the vessel wall was measured and perivenous tissue destruction was quantified using a graded scale.

Ulceration and perforation were prevented when using the tulip catheter. It also achieved more even vein wall necrosis. Tulip-catheter-treated veins show a transmural vein wall necrosis in, on average, 80% of the total circumference compared to 64% in bare-fibre treated veins. Less perivenous tissue destruction was seen with the new catheter (perivenous tissue destruction scale: tulip catheter: 1.7 vs. bare fibre: 3.8). Three weeks after treatment, we found regression of the perivenous tissue destruction as the healing process continued.

EVLA using the tulip catheter avoids ulceration and perforation of the vein associated with treatment using a bare fibre. It also results in more even circumferential vein wall necrosis and less perivenous tissue destruction.