Different venous end-to-side microanastomotic techniques: comparative study in a new rat model.

End-to-side venous anastomosis is sometimes necessary when there is the lack of a suitable vein, when there is a size discrepancy in the veins to be repaired, or when the anastomosis of multiple veins is required. The effects of elliptical vs. slit venotomy on vessel patency have not been investigated in a flap model. A new, simple, reliable, and reproducible model is described in which the femoral vein of the groin flap is anastomosed to the side of the deep dorsal penile vein. Elliptical hole and slit venotomies were tested in 26 Sprague-Dawley rats, and the anastomoses were 100% patent. The type of venotomy was not found to affect patency. Either technique is equally valid in end-to-side venous anastomosis, and the model itself is convenient for training.