THE RELEVANCE OF PREOPERATIVE CYSTOMETROGRAPHY IN PATIENTS WITH BENIGN PROSTATIC HYPERPLASIA - CORRELATING THE FINDINGS WITH CLINICAL-FEATURES AND OUTCOME AFTER PROSTATECTOMY

Preoperative water cystometrograms in 437 patients with benign prostat ic hyperplasia (BPH) were examined in a retrospective study. The cysto metrographic results were analyzed regarding the preoperative clinical features: patient age, presence or absence of urinary incontinence, h istory of urinary retention and rate of residual urine. The prognostic value in improvement in voiding difficulty and postoperative urinary incontinence was also analyzed at 1 and 6 months after elective prosta tectomy. Subjective symptoms of the patients were the primary reasons for prostatectomy, the majority of which were performed by a single co mpetent resectionist (K. T.) who evaluated the outcome but was blinded to the cystometric findings. Of these patients 263 (60.2%) had detrus or instability (group 1), while 174 did not (group 2). Vesical denerva tion supersensitivity to bethanechol chloride was noted in 47 of 375 p atients (12.5%). The difference in clinical features was significant b etween the 2 groups, with group 1 showing older patient age (p < 0.01) , and a greater incidence of urinary incontinence (p < 0.001) and rete ntion (p < 0.001). The difference between groups 1 and 2 in mean bladd er capacity (p < 0.01), compliance (p < 0.01) and a greater positive r ate of vesical denervation supersensitivity (p < 0.001) was also signi ficant. The clinical and cystometrographic parameters studied worsened with advancing patient age. Although the majority of the patients (94 .7%) were relieved of obstructive symptoms after transurethral prostat ectomy (6 months later), 113 (25.9%) were not at 1 month. Compared to 324 patients with early improvement (74.1%), those without improvement at 1 month were characterized by older age (p < 0.01), greater preval ence of preoperative incontinence (p < 0.05), retention (p < 0.01), gr eater residual rate (p < 0.05), a less compliant bladder (p <0.01) and a higher positive rate of vesical denervation supersensitivity (p < 0 .05). Cystometrographic findings, however, had no relevance to late (6 months) outcome of voiding difficulty. On the other hand, postoperati ve incontinence was noted in 100 patients (22.9%) at 1 month after tra nsurethral prostatectomy, with the majority having episodes similar to those experienced preoperatively (70.0%) as well as detrusor instabil ity (87.0%). They also were older (p < 0.01), and had a less compliant bladder (p < 0.01) and a higher positive rate of vesical denervation supersensitivity (p < 0.01) than did continent patients. Only 18 elder ly patients (4.1%) remained incontinent 6 months later, all with a les s compliant (p < 0.01) and more unstable (p < 0.01) bladder initially. The genesis of this detrusor dysfunction was believed to be aging in male patients, in whom BPH evolves and progresses. In conclusion, preo perative cystometrography in patients with BPH is valuable in that it correlated well with the clinical features and it can predict to some extent the outcome of obstructive symptoms and urinary incontinence af ter transurethral prostatectomy.