Challenging Alexis Carrel: a study in alternate microvascular techniques

Alexis Carrel pioneered the full-thickness triangulated vascular repair technique, which led to a Nobel Prize in 1912. However, microvascular anastomotic techniques that do not violate the intima, such as the VCS microclip repair and partial-thickness suturing, limit trauma to the intima, thus minimizing the potential for thrombosis. Our study compares such techniques with the standard full thickness-anastomotic repair.

Thirty-two end-to-end anastomotic repairs were performed in rat femoral arteries 1 mm or less in diameter. Group I: thirteen full-thickness repairs were completed using 10-0 nylon on a BV75 microm needle. Nineteen extraluminal repairs were performed using either a partial thickness technique with an 11-0 nylon BV50 microm needle (Group II, n = 12) or VCS nonpenetrating clip (Group III, n=7). Casted samples, injected with methylmethacrylate, were harvested at 1 and 3 weeks for histopathological evaluation. The presence of thrombosis, inflammation, endothelialization, angiogenesis and intimal hyperplasia were described for each repair.

Statistical analysis revealed no difference between the intraluminal and extraluminal techniques. Patency rates were similar between both groups: 92% (12/13) for Group I and 94% (17/18) for the extraluminal Groups II and III combined. One-hundred per cent of partial thickness suture repairs were patent. Histology revealed localized inflammation to the adventitia and media, as well as endothelialization at 1 week for anastomoses in Groups II and III. The intima of Group I demonstrated proliferative characteristics in contrast to the extraluminal groups, where secretory myofibroblasts were prevalent. The anastomotic microcirculation did not originate from the repaired artery in any of the groups.

Patency rates with end-to-end anastomotic repairs using a partial thickness technique are comparable to the standard full-thickness technique. Repairs that do not include the intima revealed focal inflammatory responses to the outer layers and more rapid endothelialization, while neighboring vessels perfuse the healing anastomosis.