Although complications such as inflammation, bleeding or infection may occur, they are relatively uncommon and not serious. A major benefit of the percutaneous no-scalpel vasectomy is that the opening in the scrotum is so small that the blood vessels are less likely to be affected. Minor risks include: 

Sperm Granuloma

A hard, sometimes painful lump about the size of a pea may form as a result of sperm leaking from the cut vas deferens. The lump is not dangerous and is almost always resolved by the body. Typically, scrotal support and mild pain relievers help relieve symptoms. 

Congestion

A sense of pressure caused by sperm in the testes, epididymis and lower vas deferens may cause discomfort for two to 12 weeks after vasectomy. Like granuloma, congestion usually resolves itself over time. 

Pain

Any surgical procedure can affect nerves and, rarely, there can be residual “phantom” pain. The testicles are sensitive organs, so such pain is common in men whether they have had vasectomy or not. It is not clear whether vasectomy increases this risk.