In a landmark medical achievement, surgeons in the United States have performed the world’s first human bladder transplant, providing a groundbreaking new treatment option for patients suffering from severe bladder damage due to cancer and other illnesses.
The complex eight-hour surgery was conducted on May 4, 2025, at the Ronald Reagan UCLA Medical Center in Los Angeles. The recipient, 41-year-old Oscar Larrainzar—a father of four from California—received both a bladder and kidney from a single deceased donor after living with bladder dysfunction and undergoing dialysis for seven years.
The procedure marks a turning point in urological medicine and organ transplantation. “This first attempt at bladder transplantation has been over four years in the making,” said Dr. Nima Nassiri, the UCLA urologist who led the surgery alongside USC’s Dr. Inderbir Gill. “For the appropriately selected patient, it is exciting to be able to offer a new potential option.”
Bladder transplantation had never been performed in humans before, largely due to its complex anatomy and the challenges of vascular and nerve reconnection. In this case, the donor bladder was surgically connected to Larrainzar’s body along with the donor kidney. Within hours, the new kidney began producing urine—and, for the first time in seven years, Larrainzar was able to urinate normally.
“This is incredibly gratifying,” said Dr. Mark Litwin, Chair of UCLA Urology. “Dr. Nassiri has spent years developing this technique, and to see it move from the lab to a living patient is a milestone not just for UCLA but for the field of organ transplantation as a whole.”
Until now, patients with non-functioning bladders had limited and often high-risk options, such as using parts of their intestines to create a urinary diversion. These procedures can lead to infections, electrolyte imbalance, and other complications. A functioning bladder transplant, if proven viable on a larger scale, could offer a safer, more effective alternative.
The successful procedure is part of a larger clinical trial, with four more surgeries planned. All recipients will require lifelong immunosuppression to prevent rejection, similar to other solid organ transplants. If initial results are positive, the trial could expand and revolutionize how bladder dysfunction is treated globally.
“This surgery represents not just a personal transformation for Mr. Larrainzar,” said Dr. Nassiri, “but a medical breakthrough that could reshape care for millions of people.”
As Larrainzar begins his recovery, his case offers hope to patients with cancer-related urological damage and raises the possibility of expanding transplant solutions to more organs previously considered off-limits.