THE EFFECT OF TWIST ON MICROVASCULAR ANASTOMOTIC PATENCY AND ANGIOGRAPHIC LUMINAL DIMENSIONS

Background. Microvascular anastomoses must be constructed perfectly in order to be successful. One of the subtle technical errors that can o ccur during construction is twisting of the anastomosis, In the presen t study, me examined the effect of twist on the immediate, 2-h postope rative angiographic dimensions and patency of microvascular anastomose s, Materials and methods. Sixty-four Sprague-Dawley rats were assigned randomly to four groups. The femoral arteries were dissected for a di stance sufficient to permit the application of an 8.5-mm-long microana stomotic approximator clamp. Microarteriorrhaphies were performed with twists of 0 degrees, 90 degrees, 180 degrees, or 270 degrees. Patency was assessed 2 h after surgery using transabdominal aortic arteriogra phy with run-off. Measurements were recorded for each anastomosis, as well as for the narrowest and widest diameters of the vessels within 1 0 mm of the anastomosis. Results. Fifty-nine of the 64 rats had techni cally satisfactory angiograms which permitted measurement of vascular dimensions. The cross-sectional areas of the narrowest areas and the a nastomoses were inversely related to the degree of twist, and were sig nificantly reduced at 270 degrees (P < 0.05), Two-hour patency rates w ere 86% with 0 degrees twist, 82% with 90 degrees twist, 71% with 180 degrees twist, and 33% with 270 degrees twist. The reduction in patenc y with 270 degrees twist was statistically significant (P < 0.05), Con clusions. Twists of 0 degrees, 90 degrees, and 180 degrees did not imp air patency at a statistically significant level, but twists of 270 de grees did significantly reduce patency of microvascular anastomoses (P < 0.05). (C) 1998 Academic Press.