In a groundbreaking advancement for organ transplantation, 41-year-old Oscar Larrainzar has become the first person in the world to successfully undergo a human bladder transplant.
This historic procedure marks a revolutionary milestone in regenerative medicine and urology.
The pioneering surgery took place on May 4, 2025, at the Ronald Reagan UCLA Medical Center. It was performed by a specialized team led by Dr. Inderbir Singh Gill from the Keck School of Medicine at USC and Dr. Nima Nassiri from UCLA. In a remarkable dual procedure, the team conducted both a kidney and bladder transplant—an unprecedented combination in medical history.
Larrainzar, who had lost both kidneys and most of his bladder to cancer, had spent the past seven years on dialysis. The eight-hour operation began with a conventional kidney transplant. What followed was a world first: the complete transplantation of a human bladder. Surgeons painstakingly reconnected intricate blood vessels and urinary pathways—a feat never before accomplished in a living patient.
“As soon as the kidney was connected, it began producing urine that flowed seamlessly into the new bladder,” said Dr. Gill. “The absence of dialysis post-surgery is a powerful indicator of success.”
This extraordinary achievement is the result of four years of dedicated research and surgical refinement. Drs. Gill and Nassiri honed their technique using deceased donor models, maintained on ventilators to mimic live conditions. A major focus was mastering the vascular reconnections critical for the bladder’s survival and function.
Traditional treatments for bladder loss, such as using intestinal tissue to create urinary diversions, often result in significant complications and reduced quality of life. A bladder transplant, by contrast, offers a structurally and functionally superior solution—one that could dramatically enhance long-term patient outcomes.
Larrainzar is now under intensive observation as doctors monitor the new bladder’s ability to store and expel urine naturally, while also watching for signs of rejection or other complications.
The success of this initial procedure has paved the way for expanded clinical trials, which could bring this innovative treatment to more patients suffering from terminal bladder conditions—individuals who today face limited, high-risk options.
“We’re encouraged by these early results,” Dr. Gill noted. “But the real breakthrough will be proving sustained bladder function over time.”
Bladder cancer continues to be a significant public health challenge, with over 85,000 new cases and 17,000 deaths projected in the U.S. for 2025, according to the American Cancer Society. For many, treatment requires bladder removal—often leaving lasting physical and emotional consequences.
The success of this transplant offers a transformative new path forward, not just for cancer survivors but also for patients facing bladder loss due to birth defects or trauma. In time, bladder transplants could become as routine as kidney or liver replacements, reshaping the future of urological care.
Quick Facts
- Patient: Oscar Larrainzar, 41
- Date: May 4, 2025
- Location: Ronald Reagan UCLA Medical Center
- Lead Surgeons: Dr. Inderbir Gill (USC), Dr. Nima Nassiri (UCLA)
- Procedure: First successful human bladder transplant, combined with a kidney transplant
- Result: Immediate kidney function, bladder operational, no dialysis required
- Next Steps: Monitor long-term outcomes, expand to clinical trials
This landmark operation signals the dawn of a new era in organ transplantation—one with the potential to restore not only function but dignity and quality of life for patients once thought to have no options left.