In general, there are relatively few risks associated with vasectomy reversals. Although uncommon, the following are risks of the procedure:

• Failed reversal
• Lack of pregnancy despite successful reversal
• Infection
• Hematoma
• Chronic pain

Some of the safety of the procedure will also depend on the type of anesthetic that you use.  Although the risks of anesthesia are generally small, the biggest risks occur with general anesthesia, followed by moderate sedation, then light sedation, and finally local anesthesia alone (numbing).  General anesthesia is when you have a tube of some sort placed in your airway to help with breathing.  Moderate sedation is when you have an IV placed with medications such as IV Versed (midazolam), morphine, fentanyl, or similar medications.  Light sedation is when you receive oral medications only.  Most academic institutions will not allow moderate or general anesthesia without a dedicated anesthesiologist performing the sedation. 

The benefits of a reversal are, of course, having a baby!

The biggest risk with a reversal is that it may just not work.  There is only so much that you can predict before the reversal itself.  Until you begin the case and sample the fluid to look for sperm, you never completely know if you'll need to do the complex (epididymovasostomy) or simple (vasovasostomy) repair.  The complex repair has lower success rates.  Also, even with an initial success, there is still the possibility that the repair closes down over time.  This occurs in approximately 15% of cases.

In some cases, the reversal itself is successful (defined as >5 million sperm), but the couple is still not able to achieve a pregnancy.  As pregnancy requires several factors, the lack of a successful pregnancy may be due to issues with the sperm itself, patient or partner age, factors on the female side, lack of sufficient attempts at intercourse, or other similar issues.

Although infections are rare, they may occur in about 1-5% of cases (depending on risk factors).  If an infection is suspected, this may require oral antibiotics.  To limit the risk of infection, you will be given post-operative instructions on how to help manage the wound.

Hematomas can occur in approximately 5% of cases.  These occur due to a delayed bleed in the scrotum, which forms a blood clot.  These are not dangerous and do not impact the success rate, but they are uncomfortable and may take months to fully resolve.  To reduce the possibility of a hematoma, you should limit your activities after the procedure for a few weeks and avoid things such as baths, saunas, hot tubs, or similar things which may dilate veins in the scrotum.

Up to 3% of men experience chronic pain following a vasectomy reversal.  In the majority of men who get chronic pain, they have had scrotal pain prior to the procedure.  Most times, this is due to referred pain from a lower back source, and the reversal only augments this pain.  This may take years to fully resolve, and undoing the reversal or performing a neurolysis (surgery to cut the nerves to the testicle) does not fix this symptom in all cases.