Evaluation of the azoospermic patient.

Azoospermia is found in up to 10 to 20 per cent of the men who present to an infertility clinic. The main causes are testicular failure and ductal obstruction. Testicular biopsy remains the definitive test used to differentiate these 2 disorders. A retrospective study of 133 azoospermic men was performed to determine the accuracy and limitations of noninvasive variables in predicting testicular failure in an effort to limit the need for diagnostic testicular biopsy. Of 49 patients (37 per cent) with ductal obstruction a third had bilateral vasal agenesis. The remaining 84 azoospermic patients (63 per cent) had testicular failure. The results of the complete evaluation of these patients are described. Among the 101 patients with a testicular biopsy confirmed diagnosis there was a significant difference in testicular size (p less than 0.001), ejaculate volume (p less than 0.001) and serum follicle-stimulating hormone (p less than 0.001) between patients with testicular failure and those with ductal obstruction. The sensitivity and specificity of various parameters were determined. The best criteria to predict ductal obstruction preoperatively are a serum follicle-stimulating hormone level of less than 2 times greater than normal and the absence of bilateral testicular atrophy (100 per cent sensitivity and 71 per cent specificity). An algorithm for evaluation of the azoospermic patient is described such that all men with ductal obstruction and a minimal number with testicular failure undergo testicular biopsy.