Combined bladder-kidney transplantation: first-in-human feasibility trial

Current surgical treatments for terminal bladder dysfunction include intestinal-based reconstructive approaches that carry substantial morbidity, particularly in immunosuppressed patients. These limitations prompted investigation into vascularised composite bladder allograft transplantation as a novel reconstructive alternative.

This is an ongoing phase 0 feasibility trial of decreased-donor bladder or combined bladder-kidney transplantation at two academic medical centres in the USA. Eligible bladder transplant recipients are adults aged 18-70 years with non-functional, poorly compliant bladders. Ideal candidates for this trial include patients with pre-existing or concurrent immunosuppression requirements. The primary endpoints are technical feasibility, defined as completion of the operation with restoration of urinary continuity with graft perfusion, and patient safety, reported through adverse events. Here, we report on the safety, feasibility, and immunological and functional outcomes from the first-in-human kidney and bladder transplant as part of the study. This study was registered with ClinicalTrials.gov, NCT06337942 and NCT05462561, and is ongoing.

The surgery was carried out in May, 2025. The patient was a 41-year-old anephric male with a terminal bladder and end-stage kidney disease from hypertension who had been on peritoneal dialysis for 7 years. Kidney and bladder were recovered from an ABO compatible 35-year-old female donor with terminal anoxic brain injury. The 8 h surgery was successful, with both organs having excellent perfusion and no intraoperative complications. On postoperative day 25, the patient developed a urine leak from the suprapubic tube tract and wound breakdown (Clavien-Dindo 4), which was managed surgically with good recovery. More than 6 months post-transplantation, the patient maintained appropriate renal (estimation glomerular filtration rate 52-55 mL/min per 1·73 m²) and bladder allograft function, with intact sensation and appropriate urge, bladder capacity of 600 mL, complete continence, spontaneous voiding with maximum flow rate 17 mL/s, and complete emptying with negligible post-void residual urine. The patient is maintained on triple therapy immunosuppression with tacrolimus, mycophenolate mofetil, and prednisone. Serial bladder biopsies have remained negative for cell-mediated or antibody-mediated rejection.

The first-in-human combined bladder-kidney transplantation demonstrates the technical feasibility of vascularised composite bladder allograft transplantation, with sustained bladder allograft function, sensation, continence, and voiding parameters, and no evidence of rejection beyond 6 months. These findings suggest bladder transplantation might represent a viable option for select patients with terminal bladder dysfunction, particularly those already requiring immunosuppression.

American Urological Association's Research Scholar Award, the National Kidney Registry, OneLegacy, and University of California Los Angeles Department of Urology.