Title: Impact of Bladder Dysfunction on Kidney Transplant Outcome: Urological Strategies to Improve Graft Survival

Aim: To generate new knowledge about bladder function after kidney transplantation, and to investigate the effect of extended urological workup both pre- and post-transplantation on kidney graft function and patient well-being.

Methods: The study consists of two substudies:

• Study 1: A retrospective, descriptive single-center cohort study to investigate the correlation between baseline patient factors, and urologic events post-transplant.
• Study 2: A prospective, descriptive, open-label single-center cohort study utilizing the results from Study 1 to stratify patients according to urological risk to treatment arms of varying intensities.

Study 1 – Retrospective study

A descriptive study exploring urologic events in approximately 1 000 patients transplanted during a ten-year period at Aarhus University Hospital. Patient information prior to transplantation such as sex, age, comorbidities, lower urinary tract symptoms (LUTS), and surgical history will be collected. During the initial 6 months post-transplantation, all mentions of urologic function and treatment will be recorded, alongside markers of graft function and urinary tract infections. 

Study 2 – Prospective study

Patients will be recruited prior to transplantation, being either on the waiting list, or having a living-donor surgery planned. Patients with a preserved diuresis will be interviewed on urologic well-being and uroflowmetry will be performed. Anuric patients will also be interviewed and undergo urodynamic studies.

The urologic risk will be used to stratify patients to different treatment regimens post-transplant with check-ups at 6 weeks, 4 months, and 12 months. 

• Treatment arm 1: Standard of care, supplemented by quality of life (QoL)-questionnaires and bladder diaries (BD)
• Treatment arm 2: As above, supplemented with interviews and uroflowmetry.
• Treatment arm 3: As above, supplemented with urodynamic studies. 

Study 2 is an open-label, adaptive trial, where patients can move between treatment arms according to predetermined criteria.

Number of patients:
Study 1: Approximately 1 000 patients
Study 2: 100 – 200 patients 

Status: Study 1 is ongoing. Study 2 is being finalized with recruitment beginning in late 2026. 

Sites: The Transplant Unit at Aarhus University Hospital: transplant center for an adult population of approx. 1,6 mio from the Central and Northern Denmark Region.