Male Contraception Without a Scalpel Injecting a Reversible Plug Under Ultrasound

This application covers methods of delivering an occlusive substance into the lumen of the vas deferens percutaneously under ultrasound guidance, methods of reversing the resulting contraception, and compositions formulated to be visible under ultrasound and other imaging. The applicant is the University of Virginia Patent Foundation.

The Problem

Vasectomy works, but it is surgery, and the specification lists what can follow: bleeding causing swelling or bruising, infection at the incision, infection in the scrotum, sperm granuloma, congestive epididymitis, recanalisation, and post procedural pain in a portion of patients.

The larger deterrent is permanence. Reversal, vasovasostomy, is a three to four hour microsurgical procedure under general anaesthesia, expensive and not widely available. Even when technically successful it does not guarantee fertility returns, because anti-sperm antibodies that develop after the original procedure persist afterwards. A man choosing vasectomy is largely choosing something he cannot undo.

That has driven research into vas-occlusive contraception: injecting or implanting a substance into the lumen to block sperm flow from the epididymis, rather than cutting the tube. RISUG, using styrene maleic anhydride, VASALGEL, using styrene maleic acid, and polyurethane and silicone implants have all been pursued along these lines. The specification notes that technical difficulties have limited them, and the central one is not the material but the delivery. Getting an injection into a tube a few millimetres across, inside the scrotum, and confirming it went into the lumen rather than beside it, has typically required surgically exposing the vas, which reintroduces much of what the approach was meant to avoid.

What This Invention Does

The method isolates the vas deferens non-surgically and administers the occlusive substance percutaneously, through the skin, under ultrasound guidance. Imaging replaces the incision as the means of knowing where the needle is, and the compositions are formulated to be echogenic, visible on ultrasound, so the operator can confirm that the material went into the lumen and see how far along it extends.

That visibility does more than assist placement. It provides a way of checking the occlusion afterwards without exploratory surgery, which matters for a contraceptive method where failure is silent until it is not.

Reversal is disclosed alongside, consistent with the framing of the whole approach as a plug rather than a cut. The vas is left anatomically intact, so restoring flow becomes a matter of clearing the material rather than reconnecting a severed tube.

Key Features

• Percutaneous administration. The occlusive substance is delivered through the skin without surgically exposing the vas deferens.
• Non-surgical isolation. The vas is isolated and stabilised for injection without an incision.
• Ultrasound guidance. Imaging confirms the needle position and placement of material within the lumen.
• Imaging visible compositions. The occlusive substances are formulated to be visible under ultrasound and other imaging modalities.
• Disclosed reversal methods. Methods of reversing the contraception are covered alongside the occlusion methods.
• Vas left intact. Nothing is severed, which is what makes reversal a materially different proposition to vasovasostomy.

Who Is Behind It

The applicant is the University of Virginia Patent Foundation, the university’s technology commercialisation arm, now operating as UVA Licensing and Ventures Group. The named inventors are John C. Herr, Kevin Simon Eisenfrats and Alexander L. Klibanov.

John Herr led the university’s Center for Research in Contraceptive and Reproductive Health and spent his career on reproductive biology and contraceptive development before his death in 2016. Kevin Eisenfrats co-founded Contraline, the Charlottesville company developing ADAM, a hydrogel vas occlusion product that grew out of this line of work. Alexander Klibanov is a specialist in ultrasound contrast agents and microbubbles, which explains the emphasis on imaging visible formulations.

The application is a divisional in a family running back to Australian application 2016353345.

Why It Matters

Male contraceptive options have not meaningfully changed in a century: condoms or vasectomy, one unreliable in practice and reversible, the other reliable and effectively permanent. Everything in between has been left to women, with hormonal methods carrying side effects that many find difficult and that have no male equivalent to compare against.

Surveys have repeatedly found substantial interest among men in a reversible long acting method. The obstacle has been developmental rather than one of demand: hormonal approaches for men have struggled with side effects and with suppressing sperm production reliably, while mechanical approaches have struggled with delivery and with proving reversibility.

Delivery under imaging is the unglamorous part that could matter most. A procedure done through the skin in a clinic, with the operator able to see the material go where it should, is a different proposition from one requiring a surgical suite. If reversal proves as straightforward as the concept implies, the decision a man is being asked to make also changes character, from permanent to provisional, and that is the change most likely to affect uptake.

Related Concepts

• Vas-occlusive contraception – the approach of plugging rather than cutting the vas deferens.
• Vasectomy – the surgical procedure this method is intended to replace.
• Medical ultrasound – the imaging that makes percutaneous delivery feasible.
• Male contraceptive – the wider field and its long standing gap.
• Contrast agent – the technology behind making the injected material visible.
• Contraline – the company commercialising vas occlusion technology from this research group.

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AU 2026202077 was published in the Australian Official Journal of Patents on 9 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.