Factors Governing the Success of Vasectomy Reversal in Achieving Pregnancy

Dr. Donald Greig

High-powered operating room microscope draped for surgery

Vasectomy is reversible but it is technically much more demanding than performing the vasectomy as it requires general anaesthesia, hospital admission, a 3-day stay, use of a microscope to perform the anastomosis of the ends of the divided vas deferens to join them. If a laparoscopic vasectomy has been performed then reversibility is not possible but alternative pathways to secure a potential pregnancy is direct extraction of spermatozoa from the testes and IVF as I discuss below.

Vasectomy reversal (vasovasostomy or epididymovasostomy) aims to restore fertility, but success depends on multiple factors. Below are key elements influencing pregnancy outcomes post-reversal:

1. Time Since Vasectomy

• Critical Factor: The longer the interval between vasectomy and reversal, the lower the success rate.

• <10 years: Highest success (80–90% sperm return; 40–70% pregnancy rates).

• 10–15 years: Moderate success (60–70% sperm return; 30–50% pregnancy rates).

• >15 years: Lower success due to epididymal blockage or sperm quality decline.

• Prolonged obstruction increases pressure, causing epididymal damage or sperm granulomas.

2. Surgical Technique

• Vasovasostomy: Reconnecting the cut ends of the vas deferens (used if sperm is present in the vas fluid during surgery).

• Epididymovasostomy: Attaching the vas directly to the epididymis (required if epididymal blockage exists).

Success rates: Vasovasostomy (85–90% patency) typically outperforms epididymovasostomy (40–70% patency).

3. Surgeon Experience

• Microsurgical expertise significantly impacts outcomes.

• High-volume surgeons achieve better patency (open tubes) and pregnancy rates.

4. Presence of Sperm Antibodies

• After vasectomy, ~60% of men develop anti-sperm antibodies, which may impair sperm motility or fertilization capacity.

• Testing for anti-sperm antibodies pre-reversal helps guide expectations.

5. Female Partner’s Fertility Status

• Age: Pregnancy rates drop sharply if the female partner is >35 years.

• Ovarian reserve, tubal patency, and ovulation status must be evaluated.

6. Post-Reversal Semen Analysis

• Sperm Return: Detectable sperm in semen within 6–12 months post-surgery.

• Azoospermia (no sperm) after reversal suggests failure or secondary blockage.

7. Original Vasectomy Method

• Extensive scarring, large vas segments removed, or prior infections reduce reversal feasibility.

One of the methods used to restore continuity is: Microdot technique vasovasostomy

The Microdot method for performing vasectomy reversal is a variation of the standard multi-layer reverse vasectomy procedure. Similar 10-0 Nylon and 9-0 Nylon sutures to microsurgical vasovasostomy are used to re-approximate both layers of the vas deferens.

The microdot technique allows for easy placement of the mucosal 10-0 Nylon sutures. The microdots guarantee even placement of the mucosal sutures. Re-alignment of the vas deferens is performed during the reverse vasectomy procedure to ensure patency of the lumen of the vas deferens and to prevent long-term scarring of the vasectomy reversal procedure.

Once the inner luminal sutures are tied, the knots are cut precisely. Because of the very small size of the vas deferens lumen, any redundant suture material can obstruct the flow of sperm along the vas deferens. Likewise, sperm leakage outside of the lumen can cause obstruction of the vas deferens. A water tight closure of the vas deferens mucosa prevents sperm from leaking out of the vas deferens after the procedure.

The outer serosal sutures are equally important in the reverse vasectomy procedure. These sutures relieve tension off of the finer inner luminal sutures and prevent the ends of the vas deferens from separating after the reverse vasectomy procedure. Liberal placement of these outer serosal micro-sutures needs to be done under a microscope as well to ensure that the ends of the vas deferens are precisely approximated.(Photographs Dr. Edward Karpman)

Pregnancy Success Rates

• Patency vs. Pregnancy: Even with sperm return, pregnancy rates lag by ~30–40% due to factors like sperm quality or female fertility.

• Cumulative Pregnancy Rates: ~40–70% within 2 years if all factors are favorable.

Alternatives if Reversal Fails

• Sperm Retrieval + IVF/ICSI: Sperm can be extracted directly from the testicle/epididymis for assisted reproduction.

Key Takeaways

• Early reversal (<10 years) offers the best chance of natural pregnancy.

• Microsurgical skill and female fertility status are pivotal.

• Post-operative seminal fluid analysis and patience (pregnancy may take 1–2 years) are essential.

Disclaimer: This newsletter is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider for any medical concerns.