SLR - August 2015 - Charles Hunter

Microvascular Anastomosis Using Fibrin Glue and Venous Cuff in Rat Carotid Artery

Reference: Sacak B, Tosun U, Egemen O, Sakiz D, Ugurlu K. Microvascular Anastomosis Using Fibrin Glue and Venous Cuff in Rat Carotid Artery. J Plast Surg Hand Surg. 2015 Apr; 49(2):72-6

Scientific Literature Review

Reviewed By: Charles Hunter, DPM
Residency Program: Wyckoff Heights Medical Center

Podiatric Relevance: The study undertaken in this article may be advantageous for the podiatric field in accessing potential risk factors that may arise during surgery. Surgery, although beneficial to many has inherent risks, which may including injury to surrounding neurovascular structures. If accidental incision into an artery occurs the conventional repair technique of microvascular anastomosis with interrupted sutures is known to be highly successful. Despite the time consuming process, the possibility of vessel narrowing and the increased risk of thrombosis at the repair site, it remains to be the gold standard for microvascular repair.

Many surgeons have been reluctant to use fibrin glue due to its thrombogenic properties as well as weaker fixating strength, however with proper technique the benefits may outweigh the drawbacks. Fibrin glue may potentially reduce the time consumed on microvascular repair as well as promote accurate hemostasis at the anastomotic site. 

Methods: Sixty-four Wistar strain rats were examined in the study with 32 rats in a control group and 32 rats in an experimental group. The rats were then anaesthetized with ketamine and xylazine and immobilized in the supine position. Using a Leica microscope the microvascular dissection was performed on all rats by the same surgeon to reduce any operator error.

In the control group a double microvascular clamp was applied and the carotid artery was transected. The cut ends of the vessels were dilated with a micro-dilator, and the lumen was rinsed with saline to remove any residual blood clots. Eight 10-0 Ethilon simple interrupted sutures were then used to anastomose the cephalic and caudal ends together.

In the experimental group, a 10 mm segment from the external jugular vein was harvested from the rat to be used as a vein graft. The lumen was cleansed with saline in preparation. A double microvascular clamp was applied and the carotid artery was transected. The vein graft was then passed onto the cephalic end of the artery using a microdilator forceps. Two simple sutures were then placed to tack the cephalic and caudal ends of the artery together. The sutures were placed at 180 degrees from one another to keep the artery in the correct location. The vein graft was then advanced caudally and placed over the anastomosis site of the carotid artery. 0.2 mL of Beriplast-P fibrin glue mixed with thrombin was applied to the anastomosis site thus gluing the vein graft onto the carotid artery. The fibrin glue was allowed to set for 2 minutes then the double clamps were released.

The duration of the procedure was recorded as the time the double clamps were occluding carotid arteries. After removal of the clamps a moist cotton gauze was applied to the artery without occluding the lumen to facilitate hemostasis. The gauze was released every 30 seconds to see if bleeding stopped. The rats were broken up into four groups consisting of eight rats per group, one group from the control group and one from the experimental group were evaluated on the third, seventh, fourteenth and twenty-first days under light microscopy.  

Results: In the control group the anastomosis time was 26.09 minutes, the bleeding time was 1.81 minutes. One aneurysm formation was observed on the twenty-first day. In the experimental group, the anastomosis time was 20.78 minutes. No bleeding was recorded after the clamps were released. One Aneurysm was formed on the twenty-firstday as well. In the control group, one week after surgery the endothelial lining on the intimal surface was not yet restored. After two weeks the endothelial lining on the intimal surface was complete. In the experimental group, one week after surgery the fibrin glue had been replaced by granulation tissue. And the endothelial lining on the intimal surface was completely restored.

Conclusion: The fibrin glue assisted venous graft is a quick and easy way to achieve reliable end-to-end anastomosis of transected arteries. The main disadvantage of the study is the additional time it takes to harvest the graft as well as the obvious problem of the increased trauma it takes to harvest an autologous graft. The fibrin graft also has the potential of triggering thrombosis. There is also still the questionable holding strength of the glue allowing it to possibly rupture. Although the fibrin glue does have promise for future applications, it is in no way ready to replace the gold standard of the microvascular anastomosis with interrupted sutures.   

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