Analysis of the urodynamics of renal transplant recipients with lower urinary tract symptoms

Purpose. Patients who undergo renal transplantation can develop bladder function complications, such as incontinence, frequency, urgency, or nocturia. A clinical urodynamic study (UDS) can be invaluable in determining the impact of known disease processes of the lower urinary tract. This study aims to present the urodynamic characteristics of patients with lower urinary tract symptoms (LUTS) after renal transplantation. Methods. A total of 66 patients with LUTS completed the International Prostate Symptom Score (IPSS) questionnaire after undergoing renal transplant surgery. All of the patients were evaluated by a detailed urodynamic study, including uroflow, cystometry, electromyography and pressure-flow. Patients were stratified according to gender and subgrouped by IPSS values to compare the urodynamic parameters. Results. Frequency was the chief complaint of renal transplant recipients with LUTS. IPSS values were similar in men and women, with the exception of voiding symptom scores (9.8 for men and 7.1 for women, p = 0.01). Maximal uroflow (female = 15.6 mL/sec vs male = 11.4 mL/sec, p = 0.007) and residual urine volume (male = 69 mL vs female = 42 mL, p = 0.04) differed significantly between men and women. The urodynamic parameters of men were compared between those who had IPSS values > 7 and those who had IPSS values ≤ 7. Maximal uroflow was significantly lower in men with IPSS values > 7 (p = 0.009). Voiding volume (p = 0.02), first sensation of bladder capacity (p = 0.04), and maximal bladder capacity (p = 0.01) were significantly higher in men with IPSS values ≤ 7. However, none of the comparative urodynamic parameters differed significantly between women with an IPSS > 7 and those with an IPSS ≤ 7. Conclusion. Although renal transplant recipients with LUTS have decreased bladder capacity and compromised bladder compliance, they still have acceptable uroflow and minimal residual urine. The clinical impact of compromised bladder compliance on the quality of life and graft function of renal transplant recipients needs to be validated. IPSS is not a good tool for defining the severity of bladder function in female renal transplant recipients with LUTS; however, IPSS values can be applied as a pre-test screen of urodynamics to define the etiology of bladder dysfunction in male transplant recipients with LUTS.