穿支血管蒂螺旋桨皮瓣蒂部血管扭转的非线性有限元模拟研究

Nonlinear finite element simulations of perforator vessels twist in perforator pedicled propeller flaps

目的研究牵张力、伴行静脉数量和动静脉间距对穿支血管蒂螺旋桨皮瓣蒂部血管扭转的影响。方法应用LSDYNA软件建立穿支血管蒂三维非线性数字化模型,分3组进行实验:(1)等长和等张扭转;(2)血管蒂为1支和2支伴行静脉;(3)穿支动静脉间距分别在0、2、4、6 mm的情况下扭转。3组实验均从0°扭转至180°,通过血管最窄处横截面积变化,反映血管的通畅性。结果 (1)等张扭转组血管蒂通畅程度明显大于等长扭转组;(2)1支管腔通畅程度大于2支,但2支静脉的管腔截面积之和仍大于1支;(3)穿支动静脉间距加大,管腔的狭窄程度也逐渐增加。结论 (1)在血管蒂扭转的同时施加牵张力,将使血管的通畅性明显降低;(2)在穿支血管蒂螺旋桨皮瓣中,2支伴行静脉的通畅性仍较1支为好;(3)穿支动静脉间距越大,扭转后绞窄越明显,甚至发生管腔闭塞。

Objectives To investigate the effects of some parameters （tension-stretch, number of concomitant vein and interval between perforator artery and vein） on the vascular patency after twisting of the perforator pedicle in perforator pedicled propeller flaps. Methods LSDYNA software was used to establish a three-dimensional nonlinear digital model of perforator consisting of an artery and a vein with both ends fixed. In Group 1, the perforator pedicle was twisted in isometric and isotonic conditions; in Group 2, the perforator pedicle was twisted with I concomitant vein and 2 concomitant veins; and in Group 3, the pedicle was twisted in the interval of 0 mm, 2 mm, 4 nun and 6 mm between the perforator artery and vein, respectively. In each group, all perforator pedicles were rotated from 0° to 180°. The effective strain was obtained to represent the perforator patency. Results In Group 1, the effective strain of perforator pedicle in isotonic condition was smaller （more patency） than that in isometric; in Group 2, the effective strain of perforator pedicle with 2 concomitant veins was larger than that of 1 concomitant vein, but the total lumen open area of the 2 veins was still greater than 1 vein; in Group 3, the effective strain of perforator pedicle increased （less patency） as the interval increased from 0 mm to 6 ram. Conclusions （1） The patency of the twisted perforator vessels is decreased when tension-stretching is added on the perforator pedicle. （2） The venous patency of preserving 2 concomitant veins is better than that of only 1 vein after the perforator-pedicle torsion. （3） The patency of the perforator is decreased when the interval between perforator artery and vein is increased.