Safe, fast, and minimally-assisted microsurgical anastomosis with combined open-loop suturing and airborne tying: a clinical and experimental study.

Background: The continuous open-loop technique accelerates anastomosis and eliminates the risk of inadvertently catching the back wall, which is the primary cause of technical failure when using interrupted sutures in microsurgical anastomosis. Combined with airborne suture tying, the total anastomosis time is significantly reduced. We conducted an experimental and clinical study to compare this combination to the conventional technique.

Methods: Experimentally, anastomoses were performed on the femoral arteries (0.60 mm) of rats in two groups. The control group used simple interrupted suturing with conventional tying, while the experimental group employed open-loop suturing with air-borne tying. We recorded the total time taken for anastomosis completion and patency rates. Clinically, we retrospectively analyzed replantation and free flap transfer cases using the open-loop suture and airborne tying technique for arterial and venous microvascular anastomoses, assessing total anastomosis time and patency rates.

Results: Experimentally, a total of 40 anastomoses were performed in two groups. The control group required 779.65 seconds, and the experimental group needed 527.4 seconds for anastomosis completion; this difference was statistically significant (p<0.001). Immediate and long-term patency rates were similar (p=0.5483). Clinically, 18 replantations were performed on 16 patients, and 17 free flap transfers were performed on 15 patients, totaling 104 anastomoses. The anastomosis success rate was 94.2% (33 of 35) for free flap transfers and 95.1% (39 of 41) for replantation cases.

Conclusion: The open-loop suture technique with airborne knot tying allows surgeons to complete microvascular anastomoses safely and in less time with minimal assistance when compared to the simple interrupted suture technique.