In vitro and in vivo validation of a novel 3D-printed vessel anastomosis device for microvascular surgery

Microvascular anastomosis is fundamental to free-flap reconstruction, yet hand-sutured techniques remain highly skill-dependent and prolong ischemic time, contributing to thrombosis and flap loss. Current suture-less devices accelerate anastomosis but are constrained by vessel-size mismatch, eversion-related intimal injury, and inconsistent arterial performance. A clinically adaptable, arterial-capable system is needed. We developed a customizable, 3D-printed intraluminal coupler with a snap-fit connection and elastic external clasp that avoids vessel eversion and preserves length. Devices were fabricated via SLA or PolyJet printing using clinically used resins. Benchtop evaluation included burst-pressure testing, tensile testing, wettability and endothelial cytocompatibility assays with oxygen-plasma surface modification. Deployment was assessed ex vivo using porcine coronary vessels and in vivo in a porcine carotid arterial model with patency monitoring over 4 h. Couplers sustained leakage pressures of ~ 90 mmHg vs. ~16 mmHg for hand-sutured controls (P < 0.01), while maintaining comparable mechanical strength (≈ 2–3 N). Plasma surface treatment reduced water contact angles (≈ 85°→≈60°) and tripled endothelial attachment, restoring confluent morphology. Ex vivo deployment achieved completion in 9.47 ± 1.20 min, a ~ 62.5% reduction vs. published suturing times. In vivo, couplers restored immediate perfusion with no leakage or thrombosis. This 3D-printed intraluminal coupler demonstrates mechanical feasibility, rapid deploy-ability, and surface-modifiable endothelial compatibility in benchtop and short-term large-animal feasibility testing, supporting its potential for further preclinical development as a vascular anastomosis technology. Future survival studies and anti-thrombogenic surface engineering will advance readiness for clinical implementation.