Microsurgical Bypass Training Rat Model, Part 1: Technical Nuances of Exposure of the Aorta and Iliac Arteries.

Background: Animal models using rodents are frequently used for practicing microvascular anastomosis-an essential technique in cerebrovascular surgery. However, safely and efficiently exposing rat's target vessels is technically difficult. Such difficulty may lead to excessive hemorrhage and shorten animal survival. This limits the ability to perform multiple anastomoses on a single animal and may increase the overall training time and costs. We report our model for microsurgical bypass training in rodents in 2 consecutive articles. In part 1, we describe the technical nuances for a safe and efficient exposure of the rat abdominal aorta and common iliac arteries (CIAs) for bypass.

Methods: Over a 2-year period, 50 Sprague-Dawley rats underwent inhalant anesthesia for practicing microvascular anastomosis on the abdominal aorta and CIAs. Lessons learned regarding the technical nuances of vessel exposure were recorded.

Results: Several technical nuances were important for avoiding intraoperative bleeding and preventing animal demise while preparing an adequate length of vessels for bypass. The most relevant technical nuances include (1) generous subcutaneous dissection; (2) use of cotton swabs for the blunt dissection of the retroperitoneal fat; (3) combination of sharp and blunt dissection to isolate the aorta and iliac arteries from the accompanying veins; (4) proper control of the posterior branches of the aorta; and (5) efficient division and mobilization of the left renal pedicle.

Conclusions: Applying the aforementioned technical nuances enables safe and efficient preparation of the rat abdominal aorta and CIAs for microvascular anastomosis.