Definition: Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
Input: Abstract: In principle, azoospermia has two explanations: occlusion of the duct system and serious dysfunction of the testicular parenchyma. Some cases of duct occlusion are suitable for reconstructive surgery. The authors describe a reconstructive technique based on full mobilization of a single loop of the epididymal duct as caudally as possible with two-layer side-to-end anastomosis to the vas deferens. To ensure follow-up evaluation of each anastomosis, unilateral anastomosis was done primarily. In a few cases, cross-over anastomosis was necessary. In cases of reoperation, if possible, this was performed on the same side. When the epididymal duct system was found empty, the contralateral epididymis was explored. Patients with postoperative oligozoospermia were offered a supplementary contralateral operation. From 1980 to 1984, 41 patients underwent epididymovasostomy. At follow-up evaluation, 35 (85%) presented sperms in repeated tests. Fifteen of these patients (37%) have fathered children. Patients with postoperative normospermia and no antisperm antibodies had an excellent fertility prognosis. The single-loop dissection technique provides anatomic specificity and a high percentage of patent anastomoses and does not interfere with the possibilities of reoperation.

Ejaculatory Ducts