The most common immediate risk of vasectomy is an inflammatory reaction caused by a reaction to sperm. Inflammatory reactions can be immediate (within days) or delayed (within months) and can occur in up to 5% of patients.

Although the male body produces, stores, and releases sperm, sperm is considered a foreign substance to the man’s body. The sperm are entirely compartmentalized and protected from the body’s immune system within the epididymis, vas deferens, seminal vesicles, prostate, and the urethra.

Exposing sperm to the immune system can cause an intense inflammatory reaction in some men.

Immediate inflammatory response

This often happens within three (3) to ten (10) days after a vasectomy procedure. The sperm that are being produce can leak into the scrotum from the open end of the bottom vas deferens. The actual volume of sperm is small but enough to cause an inflammatory reaction. Often an entire side of the scrotum is tender and slightly swollen but this can also occur on both sides.

To some extent a small amount of sperm leakage from the open-end of the bottom vas deferens is normal. Many men will not have an inflammatory reaction but will be able to contain this by forming a small sperm granuloma at the end of the opened vas deferens.

Formation of a small sperm granuloma at the end of the divided vas deferens is very helpful. This small granuloma will then function as the recycling center for sperm, minimize an immunologic reaction, and potentially relive the epididymis of acute inflammation caused by a sudden increase of pressure in the epididymis pressure.

Delayed inflammatory response

This can occur weeks to months after the initial vasectomy. Most commonly this delayed inflammation occurs in the epididymis and the tenderness is typically limited to the epididymis around the testicle. This is thought to occur because some men may experience a gradual increase in pressure within the bottom vas deferens after vasectomy. This increase pressure may cause a disruption of the protective cell layer within the inside of the epididymis. Once this cell layer is disrupted within the epididymis the immune system may recognize the foreign material in sperm and an immune response (inflammation) will occur.

Treatment for inflammation

Although these inflammatory responses can be common, they almost all resolve without any serious complications. These inflammatory reactions can occur with either closed or open ended vasectomy techniques.

Treatment often involves watchful waiting, non-steroidal anti-inflammatory medication (ibuprofen, naproxen), limited activity, and an athletic supporter. If the inflammation is unresponsive to over-the-counter anti-inflammatories then a stronger prescription steroidal medication will often treat the inflammation.