Department of Orthopedic Surgery, Columbia University Irving Medical Center, New York, New York.
J Reconstr Microsurg. 2020 Sep;36(7):501-506. doi: 10.1055/s-0040-1709478. Epub 2020 Apr 17.
End-to-side (ETS) anastomoses are necessary for many procedures in microvascular surgery, such as free flap transfers. In training courses that use the rat model, the arterial end to venous side (AEVS) anastomosis is a common training exercise for ETS anastomoses. Surgeons-in-training often inadvertently twist the artery when completing the AEVS anastomosis; however, in the clinical setting, torsion is a reported risk factor for ETS anastomosis failure. The purpose of this study was to determine if torsion in an AEVS anastomosis would have a negative effect on patency in the rat model, accurately simulating the clinical scenario.
All AEVS anastomoses were completed in 15 Sprague-Dawley rats divided into three torsion cohorts: 0, 90, and 180 degrees. Torsion was created in the AEVS anastomosis by mismatching the first two sutures placed between the free femoral artery end and the venotomy. Patency was verified at 0, 2, and 4 hours postoperation via the oxygenated-deoxygenated test and transit-time ultrasound blood flow measurements.
All AEVS anastomoses were patent 0, 2, and 4 hours postoperation according to both the oxygenated-deoxygenated test and transit-time ultrasound blood flow measurements. For the average blood flow measurements at 4 hours postoperation, the proximal measurements for 0, 90, and 180 degrees were -34.3, -18.7, and -13.8 mL/min respectively, and the distal measurements were 4.48, 3.46, and 2.90 mL/min, respectively.
Torsion of 180 degrees does not affect early AEVS anastomosis patency in the rat model. This contrasts with the clinical setting, where torsion is reported to cause ETS anastomosis failure. Since AEVS anastomosis torsion is often difficult to appreciate visually, we suggested that microvascular surgery training instructors include a method to both detect and prevent AEVS anastomosis torsion, such as by marking the free femoral artery end with a marking pen or suture before beginning the anastomosis.
端侧吻合术（ETS）在许多微血管手术中都有必要，例如游离皮瓣转移。在使用大鼠模型的培训课程中，动脉端对静脉侧（AEVS）吻合术是 ETS 吻合术的常见培训练习。接受培训的外科医生在完成 AEVS 吻合术时经常会不经意地扭曲动脉；然而，在临床环境中，扭转是报告的 ETS 吻合术失败的风险因素。本研究的目的是确定 AEVS 吻合术中的扭转是否会对大鼠模型中的通畅性产生负面影响，准确模拟临床情况。
将所有 AEVS 吻合术均在 15 只 Sprague-Dawley 大鼠中完成，分为三个扭转组：0、90 和 180 度。通过在游离股动脉端和静脉切开术之间放置的前两针缝线不匹配来创建 AEVS 吻合术的扭转。在术后 0、2 和 4 小时通过含氧-脱氧试验和渡越时间超声血流测量来验证通畅性。
根据含氧-脱氧试验和渡越时间超声血流测量，所有 AEVS 吻合术在术后 0、2 和 4 小时均保持通畅。对于术后 4 小时的平均血流测量值，0、90 和 180 度的近端测量值分别为-34.3、-18.7 和-13.8mL/min，而远端测量值分别为 4.48、3.46 和 2.90mL/min。
在大鼠模型中，180 度的扭转不会影响早期 AEVS 吻合术的通畅性。这与临床情况形成对比，在临床情况下，扭转被报道会导致 ETS 吻合术失败。由于 AEVS 吻合术扭转通常难以通过肉眼察觉，因此我们建议微血管外科手术培训讲师包括一种既可以检测又可以防止 AEVS 吻合术扭转的方法，例如在开始吻合术之前用标记笔或缝线标记游离股动脉端。
