ArticleBasic and clinical andrology2017
Reversibility of Vasalgel™ male contraceptive in a rabbit model.
Article in Basic and clinical andrology, 2017. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
14 citing papers in PubMed, 31 citations in OpenAlex.
- Evaluation of a Zinc Gluconate Neutralized with Arginine Product as a Nonsurgical Method for Sterilization of Rhesus Macaques (Journal of the American Association for Laboratory Animal Science : JAALAS · 2017Trial
- Novel male contraceptives.Future science OA · 2026Review
- Hydrogels in Contraceptive Applications and Their Mechanisms of Action.ACS applied bio materials · 2025Review
- Non-hormonal Contraception: Current and Emerging Targets.Advances in experimental medicine and biology · 2025Review
- The landscape of male contraception A narrative review.Canadian Urological Association journal = Journal de l'Association des urologues du Canada · 2024Review
- Male animal sterilization: history, current practices, and potential methods for replacing castration.Frontiers in veterinary science · 2024Review
- Male contraception: narrative review of ongoing research.Basic and clinical andrology · 2023Review
- Recent progress in advanced biomaterials for long-acting reversible contraception.Journal of nanobiotechnology · 2022Review
- Emerging approaches to male contraception.Fertility and sterility · 2021Review
- Male Contraception.The Yale journal of biology and medicine · 2020Review
- Biomaterials and Contraception: Promises and Pitfalls.Annals of biomedical engineering · 2020Review
- Development of Novel Male Contraceptives.Clinical and translational science · 2020Review
- Recent Developments in Male Contraception.Drugs · 2019Review
- The future of male contraception: a fertile ground.Translational andrology and urology · 2018Review
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 4 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundDevelopment of a non-hormonal long-acting reversible contraceptive for men could have a significant impact on reducing unintended pregnancies. Vasalgel™ is a high molecular weight polymer consisting of styrene-alt-maleic acid (SMA) dissolved in dimethyl sulfoxide being developed as a reversible male contraceptive device. It forms a hydrogel when implanted into the vasa deferentia, which prevents the passage of sperm. Previous studies in the rabbit have proven its efficacy, durability and rapid onset. This study evaluates the capacity to restore sperm concentrations in ejaculates after a reversal procedure.
methodsSodium bicarbonate was injected into the vasa deferentia after fourteen months of azoospermia following the injection of two device variations (Vasalgel 100 and Vasalgel 80). Semen samples were then collected for six months and sperm characteristics were compared to baseline levels. Samples of vasa deferentia were obtained for histological examination.
resultsSpermatozoa were present in all subject ejaculates after the reversal procedure. Sperm concentration and sperm motility were similar to baseline levels after reversal, while sperm forward progression was significantly lower and normal acrosomes were not observed. Forward progression percentages increased linearly during six months of semen collection, however, normal acrosomes were not observed at the conclusion of the study. Histologically, several vasa deferentia were clear of the device and contained an intact epithelial lining. A smaller proportion of tissues contained residual test material. A secondary intraluminal inflammatory response was seen occasionally in the tissues containing residual material. There was no difference between the two device variations for studied parameters.
conclusionsVasalgel's prevention of sperm transport for 14 months was reversed through an intravasal injection of sodium bicarbonate. Post-reversal sperm concentrations and motility returned to baseline levels during the six-month follow up. Residual material in the vas lumen or compromised epididymal and vas deferens function may be resulting in reduced forward progression and loss of acrosomes during transit through the vas. Reduced forward progression and the lack of normal acrosomes strongly suggest impaired sperm function.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.