Urodynamics in patients with pheochromocytoma: a peri-operative study of 10 cases.

Alpha receptors have been demonstrated in the bladder neck, and urinary retention may be the presenting symptom in an occasional pheochromocytoma patient. This prompted us to define the urodynamic profile in pheochromocytoma patients. Ten patients were studied. Except for 2 patients, all tumors secreted norepinephrine either alone (n = 4) or mixed (n = 4). Urodynamic studies (uroflowmetry, cystometry, profilometry, response to alpha-adrenergic agents) were performed with Urodyn 5000 chain (DANTEC) connected to a water perfused Bohler's catheter. Profilometry was done according to the Brown and Wickham technique. Normal values were those of the International Continence Society. Alpha blocker test was done by intravenous injection of thymoxamine (0.5 mg/kg) and was considered as positive if urethral closure pressure (UCP) decrease was greater than 30% after 10 minutes. Ten patients had a pre-operative study, omitting alpha-blocker test in 1 patient; 5 patients consented a postoperative study. Pre-operatively we could demonstrate: 1) Increased UCP in 8 of 10 patients, regardless of the secretory pattern; 2) Response to alpha-adrenolytic agents in 7 of 9 patients; and postoperatively: 3) Good correlation between a positive alpha-blocker test and a decrease in urethral pressure in 3 of 5 patients. Urodynamics in pheochromocytoma patients show a typical alpha-adrenergic pattern and may explain bladder dysfunction as a presenting symptom.