УДК 616.697-07-091.8

The most difficult form of male infertility to treat is azoospermia. It is identified as a complete absence of sperm in the ejaculate. Depending on the nature and causes of impairedspermatogenesis, azoospermia is divided into obstructive  (excretory,  OA)  and  non-obstructive  (secretory,  NOA).  Testicular  biopsy  is  the  most  effective  method  of diagnosis and a component of possible treatment for azoospermia. It is the only objective method of differential diagnosis between non-obstructive and obstructive forms of azoospermia.The aim:histological analysis of testicular biopsies of men with various forms of azoospermia. Мaterials and Methods.78 infertile men with azoospermia were examined. They were divided into two groups: the first group, men with NOA (n = 28); the second group, men with OA (n = 50). The biopsy was preceded by a manda-tory ultrasound  diagnosis  of  the  portal  system. The  biopsy was  performed  using  the  method  of  open  operative access. Biopsies were mostly taken from the more palpable testicle or from both testicles. Biopsies were fixed in buffered 10% formalin (pH 7.2). After 1 day, they were dehydrated in 70% ethanol and embedded in paraffin. For histological studies, sections with a thickness of 5 μm were stained with hematoxylin and eosin. Biopsies were evaluated in accordance with previously described methods.Results.Histological analysis of testicular biopsies from 28.7% of patients with a non-obstructive form of azo-ospermia showed swelling of the testicular stroma, destructive changes in testosterone-producing cells, disruption of the structure of the syncytial complexes of the spermatogenic epithelium, and the complete absence of the process of sper-matogenesis in individual tortuous seminiferous tubules, the absence of contacts between sustentocytes, and in erythro-cyte sludge in the lumen of vessels. 42.8% of patients had fibrosis of the testicular stroma, stroma swelling, thinning of the wall of convoluted seminiferous tubules, violation of the structure of the syncytial complexes of the spermatogenic epithelium, proliferation of the wall of the convoluted seminiferous tubules into their lumen, and infiltration of the testic-ular  stroma  with  lymphocytes. In  54.0%  of  patients  with  preserved  spermatogenesis  and an  obstructive  form of  azoo-spermia, it was possible to find a history of orchoepididymitis in the anamnesis; one patient (2.0%) underwent bilateral orchopexy  at  the age  of 5  years due  to  cryptorchidism;  6.0%  recalled the  trauma calculi  in  the anamnesis; and 38.0% denied any factors affecting fecundity in the anamnesis.Conclusions.The non-obstructive form of azoospermia is characterized by the following parameters: mostly a violation of the structure of the spermatogenic epithelium, a complete absence of the process of spermatogenesis in indi-vidual  convoluted  seminiferous  tubules,  a  violation  of  the  structure  of  the  hematotesticular  barrier,  and  a  violation  of blood microcirculation. The histological picture of preserved spermatogenesis is of the same type in 88.0% of patients with an obstructive form of azoospermia. In most tubules, a fixed number of cell rows is preserved, and cells of various stages of spermatogenesis are determined in them: spermatogonies, spermatocytes, a moderate number of spermatids.In the lumen of the tubules, exfoliated cells and a moderate number of spermatozoa are found.