Surgical vein occlusion--comparison of four different methods in a rat model

Among many aspects, wound healing depends on early restoration of venous blood flow across wound margins. The type of surgical occlusion of vein stumps during operations was assumed to have an influence on the early postoperative reunion of vein stumps and thereby on wound healing. Currently, there are different methods of vein stump occlusion available: ligation (e.g., Vicryl), closure using metal clips (e.g., LigaClip), coagulation using manually controlled bipolar forceps, and the use of a computer-controlled bipolar system (e.g., BiClamp). The aim of this study was to surgically and histologically compare the healing process, including new vessel formation after vein occlusion using one of the methods listed.

In a rat model (n = 50), both jugular and femoral veins were prepared, occluded twice with one of the methods mentioned above (i.e., 400 occlusions), and finally cut in-between. Groups of 10 animals were reoperated and evaluated surgically and histologically after 5 days, 10 days, 15 days, 30 days, and 90 days.

Occlusion methods using Vicryl, LigaClip, or bipolar forceps allow highly reliable vessel occlusion. Surgical evaluation showed higher occurrence of vessels in between the vein stumps after usage of Vicryl and LigaClip when compared with electrothermic occlusion methods (p = 0.017). Histologic examination showed different courses of the inflammatory reaction and varying capillary counts. Bipolar occlusion methods do cause less vessel occurrence, less inflammatory reaction, and less histologic capillary formation.

If a reconnection of the venous flow is desirable, the use of Vicryl and LigaClip might be superior to using electrothermic occlusion methods. In contrast, electrothermic methods cause less new vessel formation as well as less inflammatory reaction.