In a groundbreaking development in the field of organ transplantation, UCLA Health has achieved a historic milestone by performing the world’s first successful human bladder transplant. This landmark surgery, led by urologic transplant surgeon Dr. Nima Nassiri, represents a monumental leap forward in treating patients suffering from end-stage bladder disease, a condition that has traditionally left few effective therapeutic options. The patient, Oscar Larrainzar, a cancer survivor who had been without a functioning bladder for seven years and reliant on dialysis, underwent this pioneering procedure in May 2025. Now, one year post-transplant, he has regained full bladder function, marking a triumph that could transform the lives of many with similar debilitating conditions.
Dr. Nassiri’s innovative approach involves transplanting the bladder as a standalone, vascularized organ complete with its own blood supply. This contrasts sharply with previous methods that relied on creating a neobladder from intestinal tissue, which, while functional, often resulted in significant complications, including infections and metabolic disturbances. By preserving the bladder’s native architecture and blood flow, this new technique aims not only to restore urinary function more naturally but also to reduce the long-term risks associated with bladder reconstruction.
The procedure performed in May 2025 was part of an ongoing clinical trial at UCLA Health, designed to explore the feasibility and efficacy of combined bladder-kidney transplantation. The trial enrolled individuals with terminal bladder disease who also required kidney transplantation. Following the initial success with Mr. Larrainzar, Dr. Nassiri and his team have completed a second combined transplant and are preparing for additional cases throughout 2026, paving the way for broader application of this technique.
The postoperative recovery of Mr. Larrainzar, now 43 years old, has been remarkable. Within just one month, his bladder capacity exceeded 270 milliliters—surpassing the study’s initial benchmark of 200 milliliters at 30 days. By six months, he demonstrated a bladder capacity of 600 milliliters, equivalent to a healthy, normal bladder. This restored capacity enabled him to regain independence from catheters and dialysis, significantly improving his quality of life. He has returned to work and even enjoyed a family vacation, including swimming with his daughter for the first time in a decade.
Nevertheless, the recovery journey was not without its challenges. On the 25th day post-surgery, Mr. Larrainzar experienced a urinary leak from a suprapubic tube—a backup drainage pathway placed during the procedure. This complication led to infection necessitating a second surgery to repair the leak and remove the tube. From this experience, Dr. Nassiri’s team gleaned critical insights that will inform future surgical protocols, specifically the elimination of secondary drainage tubes in upcoming transplants to minimize similar risks.
The second patient who received the dual organ transplant had a more complicated course. While the kidney transplant was ultimately successful, the transplanted bladder encountered complications severe enough to require removal. Importantly, the patient recovered well, and efforts are actively being made to attempt a second bladder transplant, a concept termed “re-transplantation.” This potential achievement could establish a new frontier in salvage techniques for bladder transplantation failures and guide future patient management and treatment protocols.
The innovative transplantation procedure was co-developed by Dr. Nassiri in collaboration with his mentor, Dr. Inderbir Gill of USC. Their joint research and clinical expertise have shifted paradigms in urologic transplant surgery. By demonstrating that a bladder can be transplanted independently with vascular anastomosis, they challenge decades-old standards and open new avenues for organ transplantation beyond kidneys and hearts.
Clinically, this first-in-human feasibility trial has been rigorously documented and peer-reviewed, culminating in a detailed publication in the prestigious journal The Lancet on June 23, 2026. The study meticulously outlines critical benchmark criteria established prior to surgery, such as bladder capacity at defined postoperative intervals and functional outcomes. The success recorded in this trial sets a foundation for refining surgical techniques and expanding the candidate pool for bladder transplants.
Looking ahead, Dr. Nassiri emphasized the iterative nature of the trial, acknowledging each transplant as a learning opportunity that sharpens clinical protocols. His vision extends beyond individual patient success to the broader objective of delivering hope and tangible restoration of normal bladder function to thousands suffering globally. The approach not only promises improved outcomes for patients with bladder failure but also signals a new era in reconstructive urology.
Despite the inherent complexities of organ transplantation, the UCLA team’s achievements exemplify how innovation, resilience, and meticulous research can converge to redefine the limits of medical science. The prospect of safe and effective bladder transplantation that confers patients a genuine “normal life” post-recovery is no longer speculative but imminent. As clinical applications broaden and surgical refinements evolve, this pioneering work heralds a paradigm shift in urologic care.
Mr. Larrainzar’s personal testimony underscores the profound impact of this medical breakthrough. His disbelief at waking up without needing a catheter and his newfound freedom from cumbersome medical equipment symbolize the human face of transplant innovation. His journey from prolonged medical dependency to regained autonomy encapsulates the transformative promise this field holds.
Dr. Nassiri’s ongoing clinical trial also investigates the feasibility of combining bladder transplantation with kidney transplantation, addressing the complex needs of patients with multiple organ dysfunction. This dual-organ approach addresses not only the restoration of bladder function but also provides crucial renal support, offering a holistic treatment model previously unavailable.
In summation, UCLA Health’s first-in-human bladder transplant marks an extraordinary advance in surgical science. Through meticulously conducted clinical trials, rigorous postoperative evaluations, and dedicated multidisciplinary collaboration, this breakthrough paves the way for a future where organ failure no longer dictates irreversible life limitations. These findings not only inspire hope for individual patients but also expand the horizons of transplant medicine.
Subject of Research: People
Article Title: Combined bladder–kidney transplantation: first-in-human feasibility trial
News Publication Date: 23-Jun-2026
Web References: The Lancet article
References: DOI 10.1016/S0140-6736(26)00718-X
Image Credits: UCLA Health: Nick Carranza
Keywords: Health and medicine, Transplantation, Urology, Kidney
