World's First Human Bladder Transplant, world record set in Los Angeles, California

June 19, 2025

Los Angeles, California, United States--A UCLA Health surgical team led by Dr. Nima Nassiri, with assistance from Dr. Inderbir Gill successfully completed a human bladder transplant, setting the world record for the World's First Human Bladder Transplant, according to the WORLD RECORD ACADEMY.

Photo: Facebook/UCLA Health

"A UCLA Health surgical team has performed the first-in-human bladder transplant. The surgery was successfully completed at Ronald Reagan UCLA Medical Center on May 4, 2025. The team was led by Dr. Nima Nassiri, a urologic transplant surgeon and director of the UCLA Vascularized Composite Bladder Allograft Transplant Program, with assistance from Dr. Inderbir Gill founding executive director of USC Urology," the UCLA says.

"The patient had lost most of his bladder during a tumor removal, leaving the remainder too small and compromised to work. Both of his kidneys were also subsequently removed due to renal cancer in the setting of pre-existing end-stage kidney disease. As a result, he was on dialysis for seven years.

"The biggest risks of organ transplantation are the body’s potential rejection of the organ and side-effects caused by the mandatory immune suppressing drugs given to prevent organ rejection."

Photo: Dr. Nima Nassiri with patient Oscar Larrainzar/Photo Credit: Nick Carranza. Photo: UCLA

"Nassiri, formerly a urology resident with the Keck School and now assistant professor of urology and kidney transplantation at UCLA, and Gill worked together for several years at the Keck School to develop the new surgical technique, design clinical trials and secure the necessary regulatory approvals," the UCLA says.

"Nassiri and Gill collaborated for several years to develop the surgical technique. Numerous pre-clinical procedures were performed at USC and OneLegacy, Southern California’s organ procurement organization, to prepare for the first human bladder transplant."

Photo: Dr. Nima Nassiri, director of UCLA’s Vascularized Composite Bladder Allograft Transplant Program (left) with transplant patient Oscar Larrainzar before the successful bladder transplant surgery (Still from a video by Cesar Sarmiento/UCLA Health). Still from a video by Cesar Sarmiento/UCLA Health

"The recovery of the kidney and bladder from the donor was performed at OneLegacy. All parts of the procedure, including surgery and post-surgical monitoring during the transplantation, were aligned with the highest current clinical and research standards," the UCLA says.

During the complex procedure, the surgeons transplanted the donated kidney, following that with the bladder. The new kidney was then connected to the new bladder using the technique that Nassiri and Gill pioneered. The entire procedure lasted approximately eight hours.

"“The kidney immediately made a large volume of urine, and the patient’s kidney function improved immediately,” Nassiri said. “There was no need for any dialysis after surgery, and the urine drained properly into the new bladder.”

Photo: During the eight-hour procedure, surgeons transplanted both a bladder and kidney into the patient, Oscar Larrainzar, and then connected the two organs. The benefits, said UCLA’s Dr. Nima Nassiri, were immediate.
Credit: Nick Carranza/UCLA Health/University of California

"Bladder transplants have not been done previously, in part because of the complicated vascular structure of the pelvic area and the technical complexity of the procedure," the UCLA says.

"As part of the research and development stage, Nassiri and Gill successfully completed numerous practice transplantation surgeries at Keck Medical Center of USC, including the first-ever robotic bladder retrievals and successful robotic transplantation in five recently deceased donors with cardiac function maintained on ventilator support.

"The two surgeons also undertook several non-robotic trial runs of bladder recovery at OneLegacy, allowing them to perfect the technique while working closely with multi-disciplinary surgical teams."

Photo: Transplant recipient Oscar Larrainzar, whose bladder was non-functioning and who previously had both kidneys removed, rests in a hospital bed at UCLA before surgery. Credit: Nick Carranza/UCLA Health/University of California

"The bladder (from Old English blædre 'bladder, blister, pimple') is a hollow organ in humans and other vertebrates that stores urine from the kidneys. In placental mammals, urine enters the bladder via the ureters and exits via the urethra during urination. In humans, the bladder is a distensible organ that sits on the pelvic floor. The typical adult human bladder will hold between 300 and 500 ml (10 and 17 fl oz) before the urge to empty occurs, but can hold considerably more.

"The Latin phrase for "urinary bladder" is vesica urinaria, and the term vesical or prefix vesico- appear in connection with associated structures such as vesical veins. The modern Latin word for "bladder" – cystis – appears in associated terms such as cystitis (inflammation of the bladder)." (Wikipedia)

Photo: Urinary system/Wikipedia

Urinary system
Kidney
Renal pelvis
Ureter
Urinary bladder
Urethra (Left side with frontal section)
Adrenal gland
Renal artery and vein
Inferior vena cava
Abdominal aorta
Common iliac artery and vein
Liver
Large intestine
Pelvis

Photo: Ronald Reagan UCLA Medical Center. Photo: Ronald Reagan UCLA Medical Center

"Ronald Reagan UCLA Medical Center (also commonly referred to as UCLA Medical Center, RRMC or Ronald Reagan) is a hospital located on the campus of the University of California, Los Angeles (UCLA), in Westwood, Los Angeles, California, United States. It is currently ranked by U.S. News & World Report, as the best in California and the West Coast (tied with Cedars-Sinai Medical Center, also in Los Angeles). The hospital provides tertiary care to Los Angeles and the surrounding communities.

"UCLA Medical Center has research centers covering nearly all major specialties of medicine and nursing as well as dentistry and is the primary teaching hospital for the David Geffen School of Medicine at UCLA and the UCLA School of Nursing. The hospital's emergency department is a certified Level I trauma center for both adult and pediatric patients.

"Ronald Reagan UCLA Medical Center is a constituent part of UCLA Health, a comprehensive consortium of research hospitals and medical institutes affiliated with UCLA, including Ronald Reagan UCLA Medical Center; UCLA Medical Center, Santa Monica; Resnick Neuropsychiatric Hospital at UCLA; UCLA Mattel Children's Hospital; and UCLA Medical Group." (Wikipedia)