RESUMO
BACKGROUND: A narrow working space, small diameters, and the tendency to collapse with clamps make cerebral microvascular anastomosis challenging. A retraction suture (RS) is a novel technique to keep the recipient vessel lumen open during the bypass. OBJECTIVE: To provide a step-by-step overview of RS for end-to-side (ES) microvascular anastomosis on rat femoral vessels and successful use for superficial temporal artery to middle cerebral artery (STA-MCA) bypass in Moyamoya disease patients. METHODS: A prospective experimental study with approval from the Institutional Animal Ethics Committee. Femoral vessels ES anastomoses were performed on Sprague Daley rats. The rat model used 3 types of RS (adventitial, luminal, and flap RSs). An ES-interrupted anastomosis was done. The rats were observed for an average period of 16.18 ± 5.65 days; the patency was assessed by reexploration. The immediate patency on the STA-MCA bypasses was confirmed with intraoperative indocyanine green angiography and micro-Doppler; delayed patency with magnetic resonance imaging and digital subtraction angiography after 3-6 months. RESULTS: In the rat model, 45 anastomoses were performed, 15 each using the 3 subtypes. The immediate patency was 100%. Delayed patency was 42/43 (97.67%), and 2 rats died during observation. In the clinical series, 59 STA-MCA bypasses were done in 44 patients (average age, 18.14 ± 11.09 years) using RS. The follow-up imaging was available for 41/59 patients. Both immediate patency and delayed patency (41/41 at 6 months) were 100%. CONCLUSION: The RS allows continuous visualization of the vessel lumen, reduces the handling of intimal edges, and avoids incorporating the back wall in sutures, thus improving anastomosis patency.
