An old-new problem: The impact of intraoperative tissue desiccation on the regeneration of vascular anastomoses

A crucial principle in surgery is to prevent tissue dehydration during operations, a practice especially critical in microsurgical vascular anastomoses. While empirical evidence highlights its importance, objective data are crucial for optimizing tissue moisturization. This study aimed to assess the impact of hydration on the healing of vascular anastomoses. Unilateral end-to-end anastomosis of the femoral artery was performed on 24 anesthetized rats, divided into three groups: moistened (n=8), desiccated (n=8), and a benchmark group (n=8). Blood flow was measured immediately after the procedure and on the 21st postoperative day (p.o.) under anesthesia. Hematological and hemorheological parameters were assessed from blood samples collected preoperatively and, on the 7th, 14th, and 21st p.o. days. On the final day, animals were euthanized, and the anastomosed and contralateral intact femoral arteries were excised for tensile strength and histological evaluation. The results revealed a stronger inflammatory response in the desiccated group, as indicated by erythrocyte aggregation and deformability parameters. Blood flow did not change significantly between the groups, but the desiccated group had more dense connective tissue at the surgical site. The tensile strength of freshly anastomosed vessels was 1.21±0.42 N, compared to 0.47±0.11 N in the moistened group (21st day) and 0.74±0.3 N in the desiccated group. Additionally, the desiccated group showed flatter tensile strength curves (p<0.01), greater granulation tissue formation, and altered structural protein composition (collagen and elastin). Tissue dehydration during surgery markedly impaired healing of vascular anastomosis. Findings suggest disrupted tissue maturation, as evidenced by inflammatory responses, altered tensile strength curve slopes, and histological changes.