Micturitional urethral pressure profilometry for the diagnosis, grading, and localization of bladder outlet obstruction in adult men: a comparison with pressure-flow study.

Objective: To investigate the accuracy of micturitional urethral pressure profilometry (MUPP) for diagnosis, grading, and localization of bladder outlet obstruction (BOO) in men with obstructive lower urinary tract symptoms.

Methods: This prospective study included adult men with voiding symptoms qualifying for urodynamics (UDS). Patients with urethral stricture, urinary-tract infection, and inflammatory diseases of the bladder were excluded. Patients were subjected to UDS followed by VCUG the same day. UDS was performed using Solar Silver (MMS International, Enschede, the Netherlands) and included uroflowmetry, resting cystometry with UPP, pressure-flow study with MUPP, and perineal surface-electromyography. The study was performed in accordance with International Continence Society Good Urodynamic-practice Guidelines (2002). VCUG was considered the gold standard for presence and localization of BOO.

Results: A total of 64 male patients with mean age 53.3 ± 17.8 years and International Prostate Symptom Score 17.2 ± 6.8 completed the study. Uroflowmetry revealed maximum urine flow 10.1 ± 7.1 mL/s, voided-volume 218.9 ± 161.6 mL, and postvoid residue 129.8 ± 126.5 mL. For diagnosis of BOO, Abrams-Griffith number, Schaefer obstruction-grades, and obstruction-coefficient had weak agreement with VCUG (Cohen's kappa k <0.20), whereas urethral closure-pressure (Pclo) had strong agreement (k = 0.78). For grading, Pclomax had a significant positive linear correlation with Abram-Griffiths number (R(2) = 0.562; P = .0001). MUPP was able to localize the site of obstruction correctly in 55 of 57 obstructed patients.

Conclusion: MUPP is highly accurate in diagnosis, grading, and localization of BOO in men with voiding dysfunction. It might be a useful supplement to VCUG/UDS.