Guidelines do not exist despite many controversial issues; a specialist examines published data
EVEN THOUGH the American Urological Association has developed guidelines for numerous conditions, there are none for vasectomy. Yet this is one of the most common procedures performed by urologists, with more than 500,000 done annually in the United States. Guidelines would be especially helpful because there are disagreements over preoperative counseling, operative technique, postoperative follow-up, and possible long-term complications. Fortunately, the AUA Practice Guidelines Committee is considering addressing these issues in 2007. In the interim, I want to offer a review of opinions and evidence based data in the literature.
Is routine histological evaluation of vas specimens necessary at the time of vasectomy?
Androlog, an internet-based discussion group for andrologists, addressed this issue and published their findings in the Journal of Andrology 2006;27:637-640. An international discussion relayed information regarding the benefits and drawbacks of sending vas specimens to pathology.
The major benefit of histological confirmation is removal of the appropriate organ. This does not guarantee a successful outcome, however. If a specimen is not confirmed as the vas deferens, it signals the surgeon that the operation is clearly not successful. Jerry Yuan, MD, with Urology Associates of North Georgia, wrote in the Androlog review that he does not send vas segments for histology unless it is an unusual case. Occasionally, we are all confronted with a structure that we are not 100% sure is the vas deferens, as can happen with patients who have a cryptorchidism testes after an orchidopexy. Sometimes the vas is somewhat atretic, and histologic confirmation reassures the surgeon that what he removed was actually the vas deferens.
Pathological confirmation does not confirm postoperative success, though. Success can only be confirmed with postoperative semen analysis. In addition, pathological confirmation of vasa does not assure that a segment was removed from both the left and right vasa as opposed to two segments from the same vas deferens. In cases of postoperative failure, this gives lawyers more ammunition to confirm poor surgical technique.
The AUA has a policy statement regarding the standard of care for sending vas specimens. It reads as follows:
“Routine histologic confirmation is unnecessary in performing vasectomy. The American Urological Association, Inc. (AUA) recommends that physicians in practice and that residency training programs no longer require histologic confirmation of the vas deferens as a measurement of vasectomy success. The finding of azoospermia after a bilateral vasectomy is the standard for success. The persistence of sperm in the semen after a bilateral vasectomy is a surgical failure regardless of a pathologic confirmation that two segments of the vas were removed. The lack of clinical value makes the routine histologic evaluation of surgical specimens obtained by a surgeon experienced in performing vasectomies clinical unnecessary. The surgeon should decide whether a histologic evaluation is warranted. The surgeon should document in the patient's record comprehensive preoperative counseling, careful patient selection, meticulous surgical technique and whether azoospermia was achieved in the postoperative semen.”—Board of Directors, 1998, reaffirmed 2003.
Therefore, for now, histologic confirmation of vas deferens is not considered the standard of care.
What is considered a successful outcome? When should the initial semen analysis be obtained?
There are no guidelines in the United States regarding these is-sues except for the recommendation of postoperative azoospermia. Whether the semen sample should be a centrifuged specimen remains unclear, as does the timing and number of semen analyses. Although many urologists obtain a semen analysis at six to eight weeks postoperatively, several papers suggest that only 72% and 85% of patients are azoospermic at three and six months, respectively. Both time and number of ejaculations have been used to determine the optimal time to obtain the initial semen analysis. After 10-20 ejaculations, variable percentages (10%-87%) of men will be azoospermic (J Urol. 2003;170:892-896). One publication (BJU Int. 2000;86: 479-481) suggests that 62% and 97% of patients will have no sperm in the ejaculate at three and four months postoperatively. The researchers also found an 84% compliance rate with one postoperative semen analysis at three months compared with only 71% compliance with two specimens at three and four months. Smucker et al (J Am Board Fam Pract. 1991;4:5-9) surveyed patients to determine why they were noncompliant and concluded that inconvenience was the most common reason, not lack of understanding or forgetfulness.
The British Andrology Society recommends that patients should be instructed to have had at least 24 ejaculations and preferably wait at least 16 weeks before submitting a first semen sample for review (J Clin Path. 2002;55:812-816). In their “Guidelines for the Assessment of Post Vasectomy Semen Samples,” the society recommends that a freshly produced sample be examined for the presence of sperm, and if no sperm are seen, the centrifugate should be examined for presence of motile or non-motile sperm. They advise that clinicians give clearance to discontinue other contraceptive precautions after two consecutive sperm-free ejaculates. According to Smith et al, the risk of paternity after vasectomy and postoperative azoospermia is estimated to be one in 2,000 (Lancet. 1994;344:30). They reported six cases of DNA-confirmed paternity after vasectomy and two consecutive negative semen analyses. This constitutes a late failure likely from recanalization.
Regarding centrifugation, the British Andrology Society recommends centrifugation before giving patients clearance. Lemack and Goldstein found 9.7% of 229 pre-vasectomy reversal specimens had evidence of sperm or sperm parts (J Urol. 1996;155;167-169). This number is higher than is suggested in the literature without centrifugation. Jaffe et al showed that 18%-22% of patients with obstructive and non-obstructive azoospermia on standard semen analysis had sperm when centrifugation was performed (J Urol. 1998; 159:1538-50). These data do not extrapolate to patients after vasectomy. It is clear, however, that a more vigorous evaluation of the semen will identify more sperm.
How should patients with persistent non-motile sperm in the ejaculate
be managed?
It is relatively clear that patients with persistent motile sperm in the post-vasectomy ejaculate must be considered failures. This likely is a result of the vas being cut on the same side twice or early recanalization. Early failures also include patients who do not use continued protection before having semen analyses that show post-operative azoospermia.
Early persistence of non-motile sperm in the ejaculate is not uncommon and has been attributed to sperm residing in the distal ejaculatory duct or seminal vesicles. This hypothesis has never been proven, however, and the possibility of recanalization certainly exists.
The British Andrology Society has addressed this problem by creating a category of “special clearance” for patients with persistent non-motile sperm. The laboratory is asked to confirm viability of sperm with vital staining. If any motile or substantial numbers of non-motile sperm are present, clinicians are informed promptly because many surgeons will opt to repeat the vasectomy. Patients with low sperm counts (less than 1 million) of persistent non-motile sperm in their ejaculates (after at least seven months and at least 24 ejaculations) may be given special clearance following appropriate oral counseling and written advice regarding the risk of pregnancy.
The literature suggests that the risk of pregnancy with persistent non-motile sperm in the ejaculate is similar to pregnancy rates with postoperative azoospermia (Lancet. 2000;356:43-44). These are British guidelines and the AUA policy statement notes that “the persistence of sperm in the semen after bilateral vasectomy is a surgical failure.”
Should sperm cryopreservation be offered to all patients under-going vasectomy?
About 2%-6% of patients undergoing vasectomy later seek reversal. With divorce rates at approximately 50%, insurance for future costly fertility procedures should be addressed by the urologist before vasectomy. In practice, I tell patients that if they are considering sperm cryopreservation, they probably should reconsider having a vasectomy. It makes patients think about the permanent nature of the procedure. The desire for renewed fertility after vasectomy is usually a result of divorce or remarriage, but sometimes it arises in couples that simply want more children.
This review addresses many controversial issues regarding vasectomy. A more formal evidence-based review of the literature to set some recommendations regarding this very common and litigious procedure in urology is necessary.
An associate clinical professor of urology at the University of Connecticut Health Center in Farmington, Conn., Dr. Honig practices at the UrologyCenter in New Haven, Conn. and is
a member of the Renal & Urology News editorial advisory board.