thumb|A diagram of the mechanism of action of vas-occlusive contraceptive methods.

Vas-occlusive contraception is a form of male contraception that blocks sperm transport in the vas deferens, the tubes that carry sperm from the epididymis to the ejaculatory ducts.

Various vas-occlusive contraceptive methods have been researched for human-use, with interest in both reversible and irreversible methods, with the purpose of finding a suitable alternative to vasectomy and possible hormonal contraceptive treatments that are currently being researched. Potential methods include clips, plugs, valves, polymers, hydrogels, and other devices.

Types

There are numerous vas-occlusive contraceptive methods and devices that have been researched. Outlined here are a few main categories and descriptions.

Intravasal control valve (ICV)

An intravasal control valve is a reversible valve implanted in the vas deferens with the ability to either inhibit or permit sperm passage depending on the position of the device. Bionyx has developed a T-shaped intravasal control valve composed of gold and stainless steel for use in humans. Through rotation, a perforated ball within the T can be used to obstruct sperm flow or allow sperm flow. Skilled microsurgery is required for the ICV implant.

Chemosterilization

Injection of non-toxic and sclerotic chemicals in the vas deferens can result in blockage of sperm transport due to scarring on the vas deferens wall. At least 26 different chemical combinations have been attempted to achieve sterilization. Studies on over 130 men following removal of the plug within five years showed successful restoration of fertility.

ADAM

Contraline, Inc. is developing a vas-occlusive medical device known as ADAM. ADAM is an injectable hydrogel designed specifically for the dynamic environment of the vas deferens. Unlike RISUG and Vasalgel, which require injection in organic solvent, ADAM is aqueous-based. The ADAM hydrogel is inserted through a minimally-invasive, outpatient procedure. The company has made advancements in percutaneous (non-surgical) delivery of vas-occlusive devices using ultrasound guidance. Clinical trials on ADAM began in 2022.

Side effects

Vas-occlusive contraception methods are expected to have similar side effects to vasectomy, which is generally regarded as a safe and low-risk procedure.

See also

  • Male contraceptive

References

Further reading

  • Research approaches to new sterilization technology
  • In Debas, H. T. (2015). Essential surgery.
  • Tribhuwan, R. D., & Patil, B. D. (2009). Body image: Human reproduction and birth control : a tribal perspective. New Delhi: Discovery Pub. House.