Surgeons from the University of Southern California and UCLA have achieved a medical milestone by completing the world's first human bladder transplant, offering new hope for patients with severe bladder dysfunction. The groundbreaking eight-hour procedure was performed on May 4, 2025, at Ronald Reagan UCLA Medical Center by Dr. Inderbir Gill from USC and Dr. Nima Nassiri from UCLA.
Patient Profile and Medical History
The recipient, 41-year-old Oscar Larrainzar, had undergone tumor removal surgery that resulted in the loss of most of his bladder due to a rare form of bladder cancer. The remaining bladder tissue was severely compromised and non-functional. Additionally, Larrainzar had developed renal cancer against the backdrop of pre-existing end-stage kidney disease, requiring removal of both kidneys and leaving him dependent on dialysis for seven years.
"I was a ticking time bomb," Larrainzar said. "But now I have hope."
Surgical Innovation and Technique
The transplant procedure represented the culmination of over four years of development and preparation. The surgical team first practiced the technique on pigs before testing the method on donated human organs to refine their approach.
One of the primary technical challenges involved carefully removing the bladder with its blood vessels intact to ensure successful transplantation. To optimize the procedure, surgeons connected the bladder's main blood arteries together while the organ was preserved on ice, reducing the number of arterial connections required during implantation from four to two.
"This surgery is a historic moment in medicine and stands to impact how we manage carefully selected patients with highly symptomatic 'terminal' bladders that are no longer functioning," said Dr. Gill, who serves as founding executive director of USC Urology.
Immediate Post-Operative Results
The transplant outcomes exceeded clinical expectations. The new kidney began functioning immediately, producing large volumes of urine and eliminating the need for post-operative dialysis. Larrainzar's creatinine levels, a key indicator of kidney function, showed rapid improvement.
Most remarkably, just two days after returning home, the patient experienced natural urination for the first time in seven years. "He peed!" Dr. Nassiri exclaimed to his colleague. Dr. Gill responded with surprise: "No way! What the hell?"
"It's the first time he has been able to pee in seven years," Gill told reporters. "For all of us, this is huge."
Clinical Significance and Current Treatment Landscape
Traditional management for patients who lose their bladder involves repurposing part of the intestine to create a urinary diversion. However, this approach carries significant complications, with up to 80% of patients experiencing health problems due to bacterial contamination from bowel tissue. The procedure can also cause digestive issues and lacks the sterile environment necessary for optimal urinary function.
The successful bladder transplant offers a potential alternative that could address these limitations while providing more physiological function.
Future Trial Plans and Patient Selection
The surgical team plans to perform four additional bladder transplants as part of a small clinical trial designed to evaluate safety, efficacy, and potential complications. The study will assess how well transplanted bladders function and monitor for organ rejection.
"This first attempt at bladder transplantation has been over four years in the making," Dr. Nassiri said. "For the appropriately selected patient, it is exciting to be able to offer a new potential option."
Expert Perspectives and Considerations
While the procedure represents a significant advancement, transplant experts emphasize the need for careful patient selection. Dr. Rachel Forbes, a transplant surgeon at Vanderbilt University Medical Center not involved in the procedure, noted that existing alternatives for bladder replacement exist without requiring lifelong immunosuppression.
"I would be a little bit nervous that you would be exchanging some complications for others," Forbes cautioned, highlighting concerns about the lifelong immunosuppressive medications required to prevent organ rejection and their associated side effects.
The primary risks of organ transplantation include the possibility of organ rejection and adverse effects from immunosuppressive medications. These considerations make the procedure most suitable for patients who would already require immunosuppression for other transplanted organs, such as kidneys.
Clinical Team Background
Dr. Inderbir Gill serves as chairman and Distinguished Professor of the Catherine and Joseph Aresty Department of Urology at USC and is the recipient of the Dr. B.C. Roy National Award from the President of India. He previously led the first robotic kidney transplant in Mumbai, India, in 2017.
Dr. Nima Nassiri is an Assistant Clinical Professor of Urology at UCLA David Geffen School of Medicine and director of the UCLA Vascularized Composite Bladder Allograft Transplant Program, with expertise in kidney transplantation and urologic reconstructive surgery.
