Safety and efficacy of percutaneous injection of polyurethane elastomer (MPU) plugs for vas occlusion in man
Chen, Z.W.; Gu, Y.Q.; Liang, X.W.; Wu, Z.G.; Yin, E.J.; Li-Hong
International Journal of Andrology 15(6): 468-472
1992
ISSN/ISBN: 0105-6263 PMID: 1483736 DOI: 10.1111/j.1365-2605.1992.tb01140.xDocument Number: 330109
In China, physicians performed percutaneous injection of medical-grade polyurethane (MPU) in 53 men at the National Research Institute for Family Planning in Beijing and followed them for 2 years to evaluate the safety and efficacy of MPU vas occlusion. The injection of 1% procaine solution was used to kill residual spermatozoa in the distal reproductive tract. 1 year and within-subject fructose levels did not fluctuate greatly. 85% of the men reached azoospermia within 1 year after vas occlusion. 96% were azoospermic at 18 months. 2 men still had spermatozoa in the semen after 2 years (8-48 million ml-1). Both MPU plugs in most men (74%) had a regular shape. All of these men reached azoospermia by 18 months. 91% of the 11 men who had 1 regular and 1 irregular shaped MPU plug reached azoospermia by 18 months. This percentage fell to 67% for the 3 men whose MPU plugs were both irregular. The physicians had removed irregularly shaped MPU plugs in 5 men earlier and the elastomer filled the vas lumen and the surrounding vas surface. Recanalization did not occur in these 5 patients. 1 man with MPU vas occlusion developed a hematoma. 3 men experienced hemaspermia within 2 weeks after vas occlusion, but medication made it disappear within 4 weeks. Injection of 1% procaine solution may have damaged the seminal vesicles, resulting in the hemaspermia. Longterm complications did not occur.