"I don't mind a broken arm or broken leg but when they start playing with your ol' fella it gets personal," he said.
Mr Jansen was lined up for surgery with a laser but was told the laser's heat could sometimes affect other parts of the prostate. The aquablation trial was suggested instead.
"I suppose someone has to be a lab rat and find these things out. I'm quite keen to see how it goes. I don't mind being first, if it can help others," Mr Jansen said.
"There's nothing worse than going around half the day wanting to go for a pee and you can't."
Procept BioRobotics product development director Surag Mantri said the company needed a top surgeon to carry out the first operation.
"[Mr] Gilling is a world-renowned urologist and we wanted to align ourselves with someone considered a mover and shaker in the world," Mr Mantri said.
He went on to say that Mr Gilling was passionate about bringing cutting-edge technology to the field of urology.
Mr Gilling is head of Tauranga's Clinical School and has been exploring better, more advanced ways of treating prostate problems, including heading the country's first robotic surgery.
Mr Gilling compared the technique to water-blasting.
"It might be a new way to treat enlarged prostate, which is a very common disease and problem in elderly men. It may result in more rapid and consistent treatment and few side effects. That's the hope," Mr Gilling said.
Benign enlargement of the prostate
In men with prostate problems, nine out of 10 will have a prostate that has grown too big. This puts pressure on the urethra and may squeeze it enough to block outflow of urine.
An enlarged prostate problem is called benign prostatic hyperplasia (BPH) and affects more than half of all men older than 50.
Medicines or surgery are used to treat it but only when symptoms become troublesome. BPH is not prostate cancer even though most of the symptoms are the same when passing urine.
Symptoms of an enlarged prostate include trouble starting and stopping urination, needing urgently to pass urine at any time sometimes with nothing coming out and pain or burning when passing urine.
- www.prostate.org.nz