Repeated vas occlusion and non‐invasive reversal with styrene maleic anhydride for male contraception in langur monkeys

Abstract

The feasibility of a spacing method for contraception, using Styrene Maleic Anhydride (SMA) as a vas occlusive agent, has been assessed in male langur monkeys. The vas deferens of 6 animals were occluded with 60 mg SMA in 120 microL DMSO. After 150 days, the occlusion was reversed by a technique which involved palpation, percutaneous electrical stimulation, forced vibratory movement, suprapubic percussion and per-rectal digital massage of the vas segments. The vas deferens were then re-occluded with SMA and reversed by the non-invasive method after three consecutive azoospermic samples. The second vas occlusion resulted in uniform azoospermia after the third ejaculation and reversal caused the reappearance of spermatozoa in the semen to severe oligozoospermic levels in the first two ejaculations and rising to normospermia in the subsequent ejaculations. Ultrastructure of the spermatozoa by SEM and TEM and sperm function tests revealed that the spermatozoa had recovered normal morphology. Vas morphology also regained a normal pseudostratified columnar epithelium containing basal and principal cells. The results suggest that the SMA-based spacing technique for male contraception could be extrapolated to the human by use of no-scalpel injection and non-invasive reversal.

Effect of γ-dose rate and total dose interrelation on the polymeric hydrogel: A novel injectable male contraceptive

“…inside the vas tube (Guha et al, 1985;Guha, 2007).The contraceptive has been proved to be safe (Manivannan et al, 2005), antimicrobial (Sharma et al, 2003;Guha, 2005), long-term effective (Chaudhury et al, 2002;Jha et al, 2009a) and reversible (Lohiya et al, 2000). Non-invasive reversibility of SMA analogues under guidance of electromagnetic field is also possible (Jha et al, 2009b).…”

Trends in male contraception

“…A new approach to nonsurgical vas occlusion under study involves an injection into the vas deferens of a preparation of styrene maleic anhydride dissolved in dimethyl sulfoxide. In monkeys, this approach has been shown to be reversible using a combination of palpation and percutaneous electrical stimulation 14 .…”

Male contraception: Past, present and future

“…A single injection of 60 mg of RISUG can provide up to 10 years of contraception and possibly beyond (Guha et al 1993). It is effective within 72 h of injection, and can easily be removed to restore fertility using DMSO (Dimethyl Sulfoxide), sodium bicarbonate solution injection, or by non-invasive techniques such as percutaneous electrical stimulation, forced vibratory movement, suprapubic percussion and per-rectal digital massage of vas segments, but reversibility in humans has not been tested (Lohiya et al 2000;Koul et al 1998). Its effect is different from the effect of a vasectomy.…”