The Effect of Twisting on Microanastomotic Patency of Arteries and Veins in a Rat Model

Abstract

The authors examined the effect of twisting on the patency of microvascular anastomoses 3 days after surgery. A total of 69 male Wistar rats were divided randomly into four groups. The femoral arteries and veins were dissected for a standard distance. A total of 69 microarteriorrhaphies and 68 microvenorrhaphies were performed at 0 deg and with twist of the vessel ends of 90, 180, and 270 deg. Three-day patency rates for arterial microanastomoses were 100% with a 0-deg twist, 80.9% with a 90-deg twist, 68.4% with a 180-deg twist, and 64.2% with a 270-deg twist. Three-day patency rates for venous microanastomoses were 100% with a 0-deg twist, 85% with a 90-deg twist, 28.5% with a 180-deg twist, and 25% with a 270-deg twist (p = 0.047 for arteries, p = 0.001 for veins). These data are statistically significant. Moreover, assuming the risk of thrombosis to be 1 for microanastomosis without twisting, the odds ratio for the risk of vessel thrombosis for 270-deg twisting (the maximal examined degree of arterial and venous twist in the current study) is 10.08 for arterial anastomosis and 226.85 for venous anastomosis.

Effect of torsion on microvenous anastomotic patency in rat model and early thrombolytic phenomenon

“…We agree with Topalan et al 2 that the technical faults and different species of rats used (Wistar rats in the study of Salgarello et al 4 vs. Sprague-Dawley rats in the studies of Bilgin et al, 1 Topalan et al, 2 and Izquierdo et al 3 ) may alter the final outcome because of different cross-sectional histologies of the artery: 2 these variations can explain the slightly different results reported.…”

“…We agree with Topalan et al 2 that the torsion effect has no statistical meaning in terms of patency rates on a microvascular anastomosis, but we specify that this is true only for arteries, when the angle of rotation is included in the range studied: 0À270°in the study of Salgarello et al 4 and 0À360°in the study of Topalan et al, 2 with that precise length of dissection (25 mm in the study of Salgarello et al, 4 and 7.1 mm in the study of Topolan et al…”

“…These articles report slightly different results from, and give extra data (e.g., a greater number of different degrees of rotation of the microarterial and microvenous anastomoses; histopathology and scanning electron microscopy studies; and recannulation of the thrombosed vessels) to the previously published papers concerning patency rates after torsion of the arterial 3,4 and venous microanastomoses.…”

Effect of torsion on microvenous anastomotic patency in a rat model and early thrombolytic phenomenon

“…The patency rates in this current study at the end of 1 h for 90°and 180°were similar to the third-day patency rates of the study performed by Salgarello et al, which is the only previous study on the torsion of veins, done with Wistar rats. 7 But in the subsequent study, we observed that the nonpatent veins all became patent on the third day. The trombolytic process may differ in different species.…”

Mathematical explanation of the buckling of the vessels after twisting of the microanastomosis

“…1 External compression, twisting (or torsion) of the anastomosis site, tension on the anastomosis site, and kinking of the pedicle must be avoided. [1][2][3] [Twisting and torsion are used as synonyms in medical literature, and refer to rotation, either clockwise or counterclockwise, along the longitudinal axis of the vessel lumen with the axis of rotation around the center of the vessel or anastomosis. ]…”