Original Article: Clinical Investigation Cystometric evaluation of recovery in hypocompliant defunctionalized bladder as a result of long-term dialysis after kidney transplantation Takamitsu Inoue, 1 Shigeru Satoh, 2 Takashi Obara, 3 Mitsuru Saito, 1 Kazuyuki Numakura, 1 Shintaro Narita, 1 Norihiko Tsuchiya 4 and Tomonori Habuchi 1 1 Department of Urology, 2 Center for Kidney Disease and Transplantation, Akita University Graduate School of Medicine, 3 Department of Urology, Japanese Red Cross Akita Hospital, Akita, and 4 Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan Abbreviations & Acronyms MMF = mycophenolate mofetil TAC = tacrolimus UTI = urinary tract infection VUR = vesicoureteral reflux Correspondence: Takamitsu Inoue M.D., Department of Urology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan. Email: takamitu@doc. med.akita-u.ac.jp Received 1 December 2015; accepted 6 April 2016. Online publication 15 May 2016 Objectives: To evaluate the functional recovery of a pretransplant hypocompliant bladder in patients without neurological disorders, and to determine its relationship with ureteral complications, including vesicoureteral reflux. Methods: A total of 61 patients without neurogenic disorders, who underwent video water cystometry pre- and 1 year post-transplantation, were enrolled. Cystometric bladder capacity and maximum intravesical pressure were measured, and compliance was calculated by the elevation in intravesical pressure as a result of an increase in volume. The frequencies of urinary complications, including urinary leakage, pyelonephritis and vesicoureteral reflux, were also evaluated. Results: Pretransplant dialysis duration correlated with pretransplant bladder capacity and compliance (R 2 = 0.421, P < 0.001 and R 2 = 0.418, P < 0.001, respectively). A total of 16 (26.2%) patients had hypocompliant bladders <10 mL/cmH 2 O, whereas 10 of the 12 patients (83.3%) with pretransplant dialysis duration of more than 5 years had a pretransplant hypocompliant bladder. Bladder compliance significantly recovered to >20 mL/cmH 2 O (21.1–286.0) at 1 year post-transplantation in all 16 patients with a pretransplant hypocompliant bladder. No significant differences were observed for urinary leakage, pyelonephritis or vesicoureteral reflux between patients with and without a pretransplant hypocompliant bladder. Conclusions: Bladder compliance decreases logarithmically pretransplantation according to dialysis duration. Although the ability of the patients to recover varies, dysfunctions associated with a pretransplant hypocompliant bladder recover to normal ranges after renal transplantation. A pretransplant hypocompliant bladder seems not to be associated with the post-transplant prevalence of urinary complications or vesicoureteral reflux. Key words: bladder dysfunction, dialysis, kidney transplantation, vesicoureteral reflux. Introduction The capacity of the urinary bladder markedly diminishes in patients receiving long-term dialy- sis before kidney transplantation. However, a small bladder as a result of oliguria without neurogenic dysfunction, namely a defunctionalized bladder, is not limited in its ability to expand after transplantation, namely refunctionalization. 1–3 We previously reported that blad- der capacity decreased logarithmically pretransplantation depending on dialysis duration, but exceeded >150 mL at 1 year post-transplantation, even in extremely small bladders. 4 The prevalence of VUR to the graft was also found to be high in small bladders, 4 and the occur- rence of VUR might be associated with pretransplant bladder dysfunction. 5 However, the rela- tionship between bladder dysfunction before transplantation and the occurrence of VUR was not examined in our previous study, because cystometric evaluations were not carried out. 4 Previous studies that carried out urodynamic evaluations in patients with end-stage renal disease or before kidney transplantation 6–11 showed that the cystometric bladder capacity and bladder compliance decreased as dialysis duration increased. 9–11 A low compliance 694 © 2016 The Japanese Urological Association International Journal of Urology (2016) 23, 694--700 doi: 10.1111/iju.13122