A basic experimental model for end-to-end anastomosis of vessels with diameter discrepancy

Abstract

A competent knowledge of various microsurgical techniques is essential in various surgical specialities 1,2 and a microsurgical training program simulating basic technical maneuvers and difficult clinical situations is incorporated into regular residency training. 3 The end-to-end anastomosis of vessels with different luminal diameters is one of the most frequently faced technical problems in clinical microvascular surgery which is unexpectedly not considered in standard microsurgical training programs. In this letter, a new training model facing this important technical difficulty is presented which may be a useful addition to the basic microsurgical training program. The basis of the new training model for vessel size discrepancy is end-to-end anastomosis of rat femoral artery to the femoral vein by dividing them through different levels. Two different ratios of discrepancy (Moderate lumen discrepancy ratio 51:1.3‐1.5 and Severe lumen discrepancy ratio 51:1.8‐2) can be achieved in this model. The mean diameter of the vessels at a level cranial to the epigastric branches is 0.8‐0.9 mm for the artery and 1.3‐1.4 mm for the vein. Dividing the femoral artery and femoral vein at a level between the deep branches and the epigastric vessels creates a moderate lumen discrepancy of 1:1.3‐1.5 ratio for practicing endto-end anastomosis (Fig. 1). The oblique cut or spatulation of the smaller vessel end combined with closer placement of the sutures can be exercised in this situation. Saphenous artery is the continuation of the femoral artery after the epigastric branch and its most proximal part has a diameter of 0.7‐0.8 mm. In contrast, the diameter of the femoral vein at the level between the inguinal ligament and the deep branches is about 1.4‐1.5 mm. Dividing the proximal saphenous artery and cranial femoral vein and rotating the proximal cut edge of the saphenous artery cranially until reaching the proximal cut edge of the femoral vein for end-to-end anastomosis gives a severe discrepancy model with the mismatch ratio of 1:1.8‐2 (Fig. 1). End-to-end anastomosis after fishmouth incision 4 to the arterial end is exercised at this degree of discrepancy. The presented training model offers a standard and necessary exercise to overcome the problem of vessel diameter discrepancy faced in microsurgical end-to-end anastomosis in a range of 1:1.2 to 1:2. Vessel diameter discrepancy is an important clinical problem commonly faced in free tissue transfer and in our opinion, the addition of this easy and feasible model to the basic microsurgical training program may be helpful for the trainees by dealing with this important clinical problem.