likely to positively impact practice patterns for

clinicians who perform vasectomy.

The failure rate after vasectomy with a subse-

quent risk of pregnancy after documented occlusive

success is approximately 1/2,000 cases.

Vasectomy

has the lowest failure rate of all forms of contra-

ception.

Groups at many clinics adhere to strict

practice protocols, such that azoospermic PVSA

based on assessment of a centrifuged pellet ensures

the likelihood of sterility. Due to the variable

clearance time of residual sperm from the male

genital tract, PVSA timing, the number of PVSAs

required to achieve azoospermia and the number of

ejaculations after vasectomy do not correlate well

with the achievement of azoospermia after vasec-

tomy.

7,8

For these reasons, at our andrology labo-

ratory as well as at others con±rmation of sterility

after vasectomy was de±ned as azoospermia on

2 sequential PVSAs with concurrent centrifuged

pellet analyses.

In contrast to these more conservative protocols

of post-vasectomy followup, the AUA vasectomy

guidelines de±ne vasectomy success as azoospermia

or RNMS in a single uncentrifuged PVSA, de±ned

as 100,000 or greater nonmotile sperm per ml.

Compared

with

our

laboratory

de±ned

PVSA

criteria of azoospermia on pellet analysis, including

RNMS in the de±nition of occlusive success has the

potential to decrease the number of PVSAs, improve

the documented success rate, increase compliance

with followup and reduce the number of repeat

vasectomies.

We determined how the less stringent 2012 AUA

vasectomy guidelines would have altered our clin-

ical practice. Accordingly, we analyzed our PVSA

data to determine whether our clinical practice

outcomes would have changed in light of the new

criteria.

MATERIALS AND METHODS

This study was approved by the institutional review board

for the protection of human subjects at Baylor College of

Medicine. We retrospectively reviewed the records of all

men who underwent vasectomy and returned for at least 1

PVSA from January 2000 to June 2012. All PVSA data

were analyzed. The charts of all men who were not cleared

as sterile by our institutional followup protocol were

reviewed to determine whether repeat vasectomy was

performed or unintended pregnancy occurred.

All vasectomies were performed by a single surgeon

after obtaining informed consent. The vasectomy tech-

nique was conventional vasectomy using bilateral upper

scrotal skin incisions. Intravenous sedation and local

anesthesia were used. Vasal occlusion was achieved by

placing titanium clips and removing a vasal segment.

Informed consent included the institutional policy

recommendation that the patient provide 2 sequential

PVSAs at least 1 week apart beginning 3 months after

vasectomy. A masturbatory sample was collected in the

of±ce or brought in and examined within 1 hour of

collection. No appointments were scheduled and the

patient was responsible for providing the samples.

Each PVSA was initially evaluated as a complete

semen analysis performed manually by a certi±ed

andrology laboratory technician. If the sample was

azoospermic, it was centrifuged at 200

gravity for

10 minutes for semen pellet analysis. Documentation of 2

sequential azoospermic PVSAs using a protocol requiring

analysis of the centrifuged semen pellet was used to

de±ne the occlusive success rate and patient compliance

with the post-vasectomy followup protocol of our practice.

For patients who underwent repeat vasectomy the sperm

concentration and motility was recorded from each PVSA.

To determine how the revised practice criteria based on

the 2012 AUA vasectomy guidelines would have changed

post-vasectomy outcomes, each patient was reevaluated to

assess compliance and the vasectomy occlusive success

rate as well as the need for repeat vasectomy according to

the new criteria. Since each PVSA included data on

routine manual semen analysis as well as centrifuged

pellet analysis, accurate comparison was possible between

our standard andrology laboratory protocol using centri-

fuged pellet analysis and the AUA vasectomy guidelines

using uncentrifuged semen analysis.

Time to occlusive success was determined by the days

between the ±rst PVSA and documented occlusive success

on a subsequent PVSA. Because all men were required to

wait at least 3 months before the ±rst PVSA, this time was

not calculated into the difference between the time to

clearance for the institutional protocol vs the guideline

protocol. The number of repeat PVSAs that would no

longer be considered necessary based on the revised

criteria of the guidelines, the estimated cost of any un-

needed PVSAs in men who did not achieve azoospermia

but had RNMS and the number of repeat vasectomies

were determined to ascertain the cumulative bene±t of

using the new guidelines.

We used 2-tailed z-test calculations to determine sta-

tistical signi±cance between our established andrology

laboratory de±nition and the AUA vasectomy guidelines.

Data were analyzed using Excel

and SPSS

with

differences considered statistically signi±cant at p

0.05.

RESULTS

A total of 1,740 vasectomies were performed be-

tween January 2000 and June 2012. The study

cohort comprised 972 men (55.9%) who returned

to our laboratory for at least 1 PVSA. A total of

1,919 PVSAs were obtained in these men, who had a

mean

SE age of 39.7

0.2 years. Initial PVSA

performed 3 months after vasectomy in the 972

tested men revealed that 643 (66.2%) were azoo-

spermic, 278 (28.6%) presented with RNMS, 34

(3.5%) had greater than 100,000 nonmotile sperm

per ml and 17 (1.8%) had motile sperm present in

the ejaculate (part

of ±gure). Of the 972 men who

170

IMPACT OF VASECTOMY GUIDELINES ON OUTCOMES