Urodynamic Parameters and Continence Outcomes in Asymptomatic Patients with Ileal Orthotopic Neobladder: A Systematic Review and Metanalysis

Simple Summary Among the various options for urinary diversion following radical cystectomy, the orthotopic neobladder most closely resembles the original bladder both in location and function. However, a significant number of patients with these reservoirs have dysfunctional voiding. Our objective here is to provide the first systematic review focusing on the urodynamic and continence outcomes of ileal orthotopic neobladders. By summarising these important outcomes, the current paper may represent the reference manuscript for outcome comparison in future papers. The manuscript also describes the methodology of the urodynamic evaluation of the neobladders, highlighting the frequent lack of precise indications, accurate guidelines (at the state of the art, the same parameters used for the native bladder are also used for the ileal neobladders), standardised definitions, and standard values for outcome comparison. By underlining these gaps, our systematic review may aid future studies in having more adequate designs and will allow for a more accurate functional evaluation of the patients harbouring an ileal neobladder.Abstract Introduction: The orthotopic neobladder is the type of urinary diversion (UD) that most closely resembles the original bladder. However, in the literature the urodynamic aspects are scarcely analysed. Objective: To provide the first systematic review (SR) on the urodynamic (UDS) outcomes of the ileal orthotopic neobladders (ONB). Continence outcomes are also presented. Methods: A PubMed, Embase and Cochrane CENTRAL search for peer-reviewed studies on ONB published between January 2001-December 2022 was performed according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Results and Conclusion: Fifty-nine manuscripts were eligible for inclusion in this SR. A great heterogeneity of data was encountered. Concerning UDS parameters, the pooled mean was 406.2 mL (95% CI: 378.9-433.4 mL) for maximal (entero)cystometric capacity (MCC) and 21.4 cmH2O (95% CI: 17.5-25.4 cmH2O) for Pressure ONB at MCC. Postvoid-residual ranged between 4.9 and 101.6 mL. The 12-mo rates of day and night-time continence were 84.2% (95% CI: 78.7-89.1%) and 61.7% (95% CI: 51.9-71.1%), respectively.Despite data heterogeneity, the ileal ONB seems to guarantee UDS parameters that resemble those of the native bladder. Although acceptable rates of daytime continence are reported the issue of high rates of night-time incontinence remains unsolved. Adequately designed prospective trials adopting standardised postoperative care, terminology and methods of outcome evaluation as well as of conduction of the UDS in the setting of ONB are necessary to obtain homogeneous follow-up data and to establish UDS guidelines for this setting.