Chen Z, Gu Y, Liang X, Shen L, Zou W
Department of Male Clinical Research, National Research Institute for Family Planning, Beijing, P.R. China.
Contraception. 1996 May;53(5):275-9.
Histological observations of 20 occluded vas segments obstructed by the standard procedure of medical polyurethane-vas occlusion in 10 volunteers requesting vasectomy and of 20 vas segments with plugs removed from 10 vas-occluded men requesting vas reversal were carried out in order to elucidate the mechanism of vas occlusion by medical polyurethane (MPU). Twenty vas deferens in vasectomy group were ruptured, only a small amount of MPU elastomer remained within the vas lumen, most having leaked through to encircle the ruptured vas. Histomorphology of the removed vas segments from 10 vas-occluded men, who had undergone MPU-vas occlusion 4 years earlier, showed diffuse proliferation of connective tissue, fibrosis, or hyalinization of fibroplastic tissue and local infiltration of lymphocytes and macrophages. The vas lumen both proximal and distal to the plugs was completely blocked. Sperm granuloma, foreign body granuloma, proliferation of nerve fibers and local infiltration of lymphocytes were found in four vas-occluded men with painful nodules. These results suggest that the contraceptive mechanism of MPU-vas occlusion could be the result of secondary obstruction due to tissue proliferation by MPU irritation after the rupture of the vas deferens.
对10名要求输精管结扎的志愿者采用医用聚氨酯输精管阻塞标准方法阻塞的20个闭塞输精管段，以及对10名要求输精管复通的输精管阻塞男性取出栓子后的20个输精管段进行了组织学观察，以阐明医用聚氨酯（MPU）输精管阻塞的机制。输精管结扎组的20条输精管破裂，输精管腔内仅残留少量MPU弹性体，大部分已渗漏至破裂输精管周围。对10名4年前接受MPU输精管阻塞的输精管阻塞男性取出的输精管段进行组织形态学观察，结果显示结缔组织弥漫性增生、纤维化或纤维组织透明变性，淋巴细胞和巨噬细胞局部浸润。栓子近端和远端的输精管腔完全阻塞。在4名有疼痛结节的输精管阻塞男性中发现精子肉芽肿、异物肉芽肿、神经纤维增生和淋巴细胞局部浸润。这些结果表明，MPU输精管阻塞的避孕机制可能是输精管破裂后MPU刺激导致组织增生而引起继发性阻塞的结果。
