先天性双侧输精管缺如患者睾丸超微结构的改变

目的 了解先天性双侧输精管缺如（Congenital bilateral absence of vas deferens,CBAVD)患者睾丸超微结构的改变，以预测单精子卵胞浆内注射（ICSI）治疗效果。方法 对13例光镜下睾丸组织形态学正常的CBAVD患者睾丸组织进行电镜观察。结果 曲细精管界膜改变表现变睾丸曲细精管基膜增厚，分层，向管腔形成不同程度的指状突起，基膜外胶原纤维呈不同程度增多，增粗、排列紊乱，极性消失，生精上皮表现为精子细胞头部畸形，胞核染色质呈现明显颗粒状结构。出现核内空泡，精子细胞中段线粒体鞘部分或完全缺失，顶体内陷，顶体囊增大，内有电子密度不高的片层结构（5例）。支持细胞表现数目增多，胞浆内脂质颗粒及降解小体明显增多。有时可见支持细胞之间的紧密连接消失（2例）。结论 CBAVD患者睾丸组织超微结构异常主要表现为界膜与精子细胞的改变，CBAVD所致的无精子症除了梗阻因素外，同时合并了睾丸性因素。

Study of testicular ultrastructure in congenital bilateral absence of vas deferens

Objective To study the testicular ultrastructure in CBAVD patients. Methods Ultrastructure of testicular tissue was studied in 13 CBAVD patients with azospermia whereas the testicular morphology under light microscopy was normal. Results The presence of thickening,multilayered,finger shaped protuberent to seminiferous tubules in variable degrees in basement membrane was confirmed at ultrastructural level in 13 CBAVD patients.Collagen fibres revealed an increase in number,proliferation,disturbance in variable degrees and no polarity in all the 13.Malformed heads,metachromatic granules nuclei with abundant bulla,full or partial absence of middle mitochondria sheath were seen in most of spermatozoa.Of 5 cases,invagination and low electronic density layered materials were presented in acrosome and acrosomal cyst respectively.Most of sertoli cells presented abundant lipid droplets and degradative bodies in their cytoplasm in all cases.In 2 cases,tight junctions between sertoli cells were not found. Conclusions Microstructural alteration of testicular tissue,especially conspicuous in spermatozoa and in the limiting lamina of testis,might be a contributory cause of azospermia in addition to the clinical absence of vas deferens.