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1 Department of Urology, University of Michigan, Arbor, Mich
2 Department of Family Medicine, University of Michigan, Ann Arbor, Mich
3 Departments of Urology, Obstetrics/Gynecology, and Physiology, University of Michigan, Ann Arbor, Mich
CORRESPONDING AUTHOR: Timothy G. Schuster, MD, Department of Urology, University of Michigan, 2917 Taubman Center 0330, 1500 E Medical Center Dr, Ann Arbor, MI 48109-0330, tgschust{at}umich.edu
| ABSTRACT |
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METHODS During vasectomy men were randomly assigned to flush the prostatic end of the vas deferens with 10 mL of normal saline (intervention group, n = 50), while the remaining men (n = 56) served as controls. Sperm counts were performed on the immediate postprocedure urine specimen and on semen samples at 1, 6, and 12 weeks after vasectomy.
RESULTS The postprocedure urine specimens from the intervention and control groups contained 29.2 x 106 and 0.004 x 106 sperm, respectively (P <.001). Total sperm counts in the ejaculate for intervention and control groups at 1, 6, and 12 weeks were (in millions of sperm): 14.1 and 13.8, 0.4 and 8.0, and 0.0 and 0.011, respectively (P >.05 at all time points). There was no difference in the rate at which the men in the 2 groups achieved azoospermia.
CONCLUSIONS Vasal perfusion with saline during vasectomy was effective in removing sperm from the distal vas; however, perfusion did not increase the rate at which men achieve azoospermia.
Key Words: Vasectomy vas deferens azoospermia sterilization, reproductive system reproductive and urinary physiology irrigation
| INTRODUCTION |
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Some investigators have suggested that the number of ejaculates after surgery can shorten the time to azoospermia.6,7 Others, however, have shown that coital frequency alone does not necessarily improve the time to clearance of sperm after vasectomy.8
We hypothesized that flushing the prostatic end of the vas deferens with saline might shorten the time needed to reach azoospermia. Although previous studies have examined the role of vas irrigation at the time of surgery, many have lacked randomization, had poor postoperative compliance, or included as success the presence of nonmotile sperm in the ejaculate after vasectomy. The purpose of the this study was to examine the effect of intraoperative irrigation of the vas deferens on the semen counts after vasectomy, with special regard to the time needed to reach azoospermia.
| METHODS |
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A urine specimen was collected from all patients immediately after the vasectomy and analyzed for the presence of spermatozoa. If sperm were seen in the postprocedure urine, a quantitative count was performed. Semen specimens were examined at 1, 6, and 12 weeks after vasectomy, and quantitative sperm counts were performed on each occasion. Azoospermia was defined as the total absence of sperm from the ejaculate. Differences in sperm counts between the 2 groups were compared using the Mann-Whitney rank sum test. Differences in the percentages of men in each group who achieved azoospermia were compared using the log-rank test. The study had a power of 80% to detect a difference of 16% in the proportion of men achieving azoospermia.
| RESULTS |
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The findings, displayed in Table 1
, show lower sperm counts for the control group in the urinalysis immediately after vasectomy, but there were no significant differences in sperm counts between the 2 groups at 1, 6, and 12 weeks.
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| DISCUSSION |
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Other investigators have studied the effectiveness of perfusing the vas with spermicidal compounds during vasectomy to rid the distal duct of motile sperm.1417 These investigators, as did Yu et al,11 assumed that non-motile sperm will not cause a pregnancy, which is a standard that can be questioned.
In their review of the literature, Mumford and Davis18 note that the collected results of the aforementioned studies are equivocal and do not clearly show whether perioperative flushing reduces the time required to reach azoospermia after vasectomy. In particular, discrepancies exist among published trials with regard to the definition of azoospermia. Many of the studies reviewed by Mumford and Davis used the absence of motile sperm from the ejaculate as their desired endpoint, allowing the presence of only nonmotile sperm to be sufficient evidence of adequate contraception.10,11,14,1921 It should be noted, however, that nonmotile sperm in the ejaculate in the first few weeks after vasectomy can be an indication of early recanalization of the vas deferens.22 Furthermore, Thomson et al23 reported a case in which a seemingly infertile male with only nonmotile sperm impregnated his wife.
Our investigation was randomized, with all consecutive vasectomy patients offered entry into the study. Compliance in follow-up semen specimens was 100%. The study had sufficient power to detect a clinically meaningful difference. Given the great number of patients that would need to be treated to achieve earlier azoospermia in only a small number of patients, we do not believe vas perfusion in practice is justified.
In our study, intraoperative saline perfusion was highly effective in removing sperm from the distal vas deferens, as evidenced by the difference in the total sperm numbers in the urine immediately after vasectomy between the two groups. Despite this finding, irrigation did not change the mean sperm numbers in the ejaculate samples of either group at 1, 6, or 12 weeks, nor did it decrease the time required to achieve azoospermia. The residual sperm seen in semen checks after successful vasectomy may reside in the seminal vesicles, where their anatomic location is not affected by perfusion through the vas deferens alone. Because sperm stored in the seminal vesicle are typically nonmotile as a result of its toxic environment,24 and because nearly all sperm seen after a successful vasectomy are nonmotile (until azoospermia is observed), this theory seems quite plausible.
This study has limitations that could be evaluated in future studies. We did not give specific instructions to patients regarding frequency of ejaculation after vasectomy, nor did we record this information from patients. As mentioned, these factors may have an additional impact on time to achieve azoospermia.
| FOOTNOTES |
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Received for publication December 6, 2002. Revision received March 21, 2003. Accepted for publication May 26, 2003.
| REFERENCES |
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This article has been cited by other articles:
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A. A. Makhlouf and C. S. Niederberger Ensuring Vasectomy Success: What Is the Standard? J Androl, September 1, 2006; 27(5): 637 - 640. [Full Text] [PDF] |
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K. C. Stange and W. L. Miller In This Issue: The Patient Voice, Clinical Research, Clustered Data, and the Wonca Research Conference Ann. Fam. Med, May 1, 2004; 2(3): 194 - 197. [Full Text] [PDF] |
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