Can persisting detrusor hyperreflexia be predicted after transurethral prostatectomy for benign prostatic hypertrophy?

Detrusor hyperreflexia (DH) is frequently found in patients with benign pro static hypertrophy (BPH) and persists in 30-50% of patients after successfu l removal of bladder neck obstruction by transurethral prostatectomy (TUR-P ) or surgical enucleation of the prostate. It would be beneficial for surge ons to be able to identify patients who are at risk of persistent post-oper ative urinary irritation symptoms and DH. Twenty-three patients who showed DH pre-operatively were included in this study. Of these 23 patients, four had neurogenic bladder because of previous cerebrovascular disease. The oth er 19 patients were considered to have DH because of BPH. These 19 patients were classified according to their cystometry chart patterns, Pattern 1 wa s the continual sporadic onset and offset of DH, pattern 2 was a single epi sode of DH at a bladder volume of <160 mt, and pattern 3 was a single DH ep isode at a bladder volume >160 mt. Preoperative single-photon emission comp uted tomography (SPECT) was performed on 1 1 patients. Cystometric findings at 3 to 6 months after surgery were compared with the pre-operative findin gs. Four of the six patients with pattern 1 (67%) and all patients with pat tern 3 (100%) showed an absence of DH after surgery. In contrast, all five patients with pattern 1 and all four patients with neurogenic bladder showe d persistent DH. Compared with pattern 3 patients, pattern 1 patients more frequently complained of urgency before surgery, and their symptoms and uro flowmetry parameters did not improve afterward. Among 14 patients who had p re-operative SPECT, all eight patients with low cerebral blood flow in the frontal region showed persisting DH. Conversely, all six patients with norm al SPECT results showed no DH after surgery. When DH occurs repeatedly (pat tern 1) or occurs at a bladder volume of <160 mt (pattern 2), there is a gr eater risk of post-operative irritation symptoms. Abnormal SPECT findings c an also predict the post-operative persistence of DH. Combing these two pre -operative examinations allows us to predict better post-operative DH in pa tients with BPH. (C) 2000 Wiley-Liss, Inc.