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BACKGROUND: Microvascular anastomosis is very risky. There have been many studies of solid, non-degradable stent-assisted small vessel anastomosis, but there are still temporary, traumatic issues. Thereafter, degradable woven-type stent becomes an issue of concern. OBJECTIVE: To investigate the feasibility of polylactic acid microvascular stent anastomosis for repairing micro vessels. METHODS: Polylactic acid fiber-loops were multi-directionally hot-stretched and formed to prepare micro-stent of “M” shape. The diameter of the stent was 0.5 or 1mm. It was applied to the root and middle of the tail artery of 24 Sprague-Dawley rats (provided by Shanghai Xipuer-Beikai Experimental Animal Co., Ltd.). These rats were randomly divided into a stent anastomosis (group A) and a non-stent anastomosis (group B). The time of vascular anastomosis, the immediate patency rate of anastomotic vessels and the survival rate in both groups were recorded. Ultrasound Doppler observation was performed to observe the tail artery circulation at postoperative 2 weeks. The tail artery was histologically observed at postoperative 4 weeks. The experiment was approved by the Animal Ethics Committee of Fengxian Branch of the Sixth People’s Hospital of Shanghai (approval number: 20160225124025). RESULTS AND CONCLUSION: (1) The immediate patency rate of anastomotic vessels in both groups was 100%. The anastomosis time in the group A was significantly shorter than that in the group B [(3.0±0.5) vs. (5.0±0.6) minutes, P < 0.05]. The survival rate of replantation in the group A was significantly higher than that in the control group [(95.8±1.5)% vs. (91.7±1.7)%, P < 0.05]. (2) Ultrasound Doppler examination showed blood flow passed through the anastomotic orifice and its distal and proximal side in the group A, while in the group B, there was thrombosis at the anastomotic orifice and distal side, and the lumen was occluded. (3) Hematoxylin-eosin staining showed that there was no thrombus in the tail artery in the group A, the stent and the anastomosis were completely covered with the intima, and the lumen was smooth. The lumen in the group B was oblate, which showed a thrombus formation and a narrow lumen. (4) These results suggest that polylactic acid micro-stent can meet the requirements of microvascular anastomosis replantation, and can significantly shorten the time of vascular anastomosis, improve the effect of anastomosis and suture, and increase the survival rate of replantation. [ABSTRACT FROM AUTHOR]