Investigation of a novel absorbable protein stent for microsurgical vasovasostomy in rats: An experimental study

Microsurgical 2-layer vasovasostomy is a commonly used technique to treat vasal obstruction in male infertility, and optimizing the surgical approach has important clinical implications.

To compare the differences between stent-assisted vasovasostomy and the conventional technique in terms of operative time, vasal patency rate, and reproductive function.

This experimental study included 54 male Sprague-Dawley rats (8-9 wk, 300 $\pm$ 15 gr) and 12 female rats (7-8 wk, 250 $\pm$ 13 gr, used for co-housing experiments). The male rats were randomly assigned to 3 groups (n = 18/each): control groups, conventional groups, and stent groups. Postoperative assessments were performed at 2, 5, and 8 wk, including operative time, vasal patency rate, morphological changes (such as epithelial integrity and granuloma formation), immune response (serum immunoglobulin G and anti-sperm antibodies), and reproductive function (semen quality, pregnancy rate, and reproductive hormone levels).

The average operative time in the stent group was significantly shorter than in the conventional group (28.8 $\pm$ 5.2 min vs. 70.4 $\pm$ 4.0 min, p $<$ 0.001). The vasal patency rates were 100% and 91.7%, and the pregnancy rates were 83.3% and 75.0% in the stent-assisted and conventional groups, respectively. No statistically significant differences were observed between the 2 groups in terms of immune response (serum immunoglobulin G, anti-sperm antibodies), semen parameters, or reproductive hormone levels. Histological examination showed that most anastomotic sites exhibited good structural integrity without marked inflammation, with only one rat showing mild granuloma formation.

The absorbable protein stent shortens the operative time of vasovasostomy while maintaining favorable patency and reproductive outcomes. It shows promising potential for optimizing microsurgical vasovasostomy in clinical practice.