Studies on Residual Sperm in the Distal Ductal System Folowing Vesectomy

Lee, Hee Yong

Abstract

It is generally accepted that, after vasectomy, the sperm remaining in the reservoirs and distal ductal system are gradually expelled with each ejaculation, eventually resulting in a sperm-free ejaculate. Therefore, vasectomy for the purpose of contraception should be considered successful only when the ejaculate becomes completely free of sperm. The criteria of the procedure which have been used after the operation to determine when the ejaculate becomes sperm-free are quite variable from a minimum of one ejaculation to a maximum of 16 ejaculations with 2 sperm-free specimens. Thus, no previous study has determined the exact number of ejaculates required to produce azoospermia following bilateral vasectomy Under these circumstances, the author has performed studies on residual sperm in the distal ductal system following vasectomy. In order to determine the exact end point of azoospermia on Korean male after vasectomy, 1 preoperative semen analysis, and more than 10 postoperative seven analyses are performed on 100 vasectomized volunteers. These 100 volunteers are devided into two groups 1) Pre., and post-operative semen test group, consists of 50 cases. 2) Postoperative semen test group, comprises of 50 cases. The subjects are requested to collect semen specimens at home or at doctor's office in test tubes or condomes provided by the doctor the night before or just before the operation for the pre-, and post. operative semen tests. The subjects are received 10 condoms or tubes after the operation for post. operative semen tests. Semen analyses are carried out by standard method. When there are too few cells observed, less than 100,000 sperm per ml, the number of sperm per low power field of the microscope is estimated by taking an average number found in each of 10 fields of the microscope. In cases of an absence of sperm, more than 50 fields of low power of the microscope are carefully searched. One spermatozoon of low power field is tentatively estimated at 50,000 sperm per ml. .Semen specimens are collected every 5 days about 7 days after the vasectomy. 3) Non-vasectomized semen tests group, consists of 10 cases Besides the above mentioned two groups, ten non-vasectomized normal men are requested to collect 7 daily successive semen specimens as a control group. By way of conclusion, the results of the present study are summarized as follows: l) The rate of sperm disappearance after vasectomy related directly to the number of ejaculations. 2) In pre-, and post-operative sperm test group, all the subjects were less than l million per ml of sperm after 6 ejaculations, and 88 per cent of the subjects were sperm-free after 10 ejaculations postoperatively. 3) In post-operative sperm test group. all the subjects were less than l million per ml. of sperm after 7 ejaculations, and 86 percent of the subjects were sperm-free after 10 ejaculations postoperatively. 4) Sixty-five per cent of the sperm in non-vasectomized ordinary man came from the proximal vasa to the suspected point of vasectomy and epididymis 5) First specimen after vasectomy contained 35 per cent of the sperm found in the preoperative specimen. 6) Percentage decline in sperm output with each successive semen specimen was steady and regular, since the each specimen contained 35 per cent of the sperm of the specimen preceding it.