Association of high bladder neck elevation with urodynamic bladder outlet obstruction in patients with lower urinary tract symptoms and benign prostatic hyperplasia

Abstract

Objective: To ascertain the association of cystourethroscopic findings of bladder neck elevation with urodynamic bladder outlet obstruction (BOO) in patients with lower urinary tract symptoms and benign prostatic hyperplasia (LUTS-BPH).

Materials and methods: Study subjects were 646 consecutive men aged >40 years diagnosed with LUTS-BPH at Seoul National University Hospital from December 2005 through January 2012. We collected the International Prostatic Symptom Score, serum prostate-specific antigen levels, prostate volume measured by transrectal ultrasonography, uroflowmetry with postvoid residual volume, and urodynamics with a pressure flow study. We examined the degree of lateral lobe protrusion of prostate, bladder neck elevation degree (BNE-D), and bladder neck elevation angle (BNE-A) under a cystourethroscopic examination.

Results: When we examined BNE by cystourethroscope, the mean BNE-A was 26.1°. Higher BNE-D was strongly positively correlated with BNE-A, but neither was associated with the degree of lateral lobe protrusion of prostate. Patients with higher BNE-A (≥ 35°) had higher BOO index and more obstructed voiding patterns than those with lower BNE-A (<35°). BNE-A was positively correlated with BOO index (r = 0.186). However, we identified only total prostate volume (odds ratio [OR], 1.036), maximal flow rate (Qmax; OR, 0.843), and detrusor pressure at Qmax (PdetQmax; OR, 1.278) as significant predictors of BOO in the multivariate analysis.

Conclusion: In sum, patients with higher BNE-A (≥ 35°) by cystourethroscope had higher BOO index and more obstructed voiding patterns than those with lower BNE-A (<35°). Moreover, both BNE-D and BNE-A were positively correlated with BOO index. Thus, cystourethroscopic findings of BNE status can be helpful to predict urodynamic BOO in the patients with LUTS-BPH.