A Novel Intraluminal Microtube Anastomosis System (IMAS) for Rapid Rat Microvascular Reconstruction: Development and Experimental Evaluation

Background: Conventional interrupted microvascular anastomosis can be performed by skilled surgeons, but it requires extensive experience and is time-consuming. In this study, we developed an intraluminal microtube anastomosis system (IMAS) incorporating circumferential intimal anchoring ridges that mechanically retain each arterial end during circumferential ligation. This study compared IMAS with conventional interrupted microsurgical anastomosis in a rat infrarenal abdominal aortic model. Methods: Forty male Sprague-Dawley rats were randomly allocated to IMAS (n = 20) or conventional interrupted microsurgical anastomosis (n = 20). The primary outcome variable was anastomosis time. Secondary outcome variables were patency at 1 week and 1 month, assessed using color Doppler ultrasonography and visual inspection at necropsy. Results: Mean anastomosis time was 5 min 30 s ± 60 s in the IMAS group and 20 min 32 s ± 75 s in the conventional group (P < 0.001), representing a reduction of approximately 73% in the IMAS group. One-week patency was 95% in both groups (19/20; P = 1.000). At 1 month, patency was 85% in the IMAS group (17/20) and 90% in the conventional group (18/20; P = 0.633). No gross device migration, aneurysmal dilatation, or anastomotic leakage was observed in patent IMAS-treated vessels. Conclusions: In this experimental model, IMAS significantly reduced anastomosis time while maintaining a short patency rate similar to that of conventional interrupted micro suturing. These results support the need for further evaluation of mechanical intimal fixation strategies, including future histological assessments and long-term follow-up.