Effect of the two-wall-stitch mistake upon patency of rat femoral vein anastomosis: Preliminary observations

Anastomotic patency is believed to be the most important factor in microvascular surgery. The two-wall stitch is a technical error commonly considered to cause thrombosis of the anastomosis, especially on the venous side. In order to demonstrate the real effect on vein patency of the two-wall stitch, the authors performed a standardized mistake after correct microanastomosis on the femoral vein of 15 rats, with one stitch passing through the whole thickness of the two walls of the vein. Traditional correct anastomoses on the contralateral side were used as controls. Patency was assessed at 5, 20, and 60 min and at 24 h by the milking test, and by direct section of the vessel at 24 h. The results showed no statistically significant difference between the two techniques. Histological examination confirmed the clinical judgment about the vessel's patency, and ultrastructural microscopy evidenced only mild signs of endothelial activation. In conclusion, this study indicates that the occasional two-wall stitch does not necessarily increase the risk of venous occlusion in anastomoses of the rat femoral vein.