A NEW TECHNIQUE FOR ASSESSING DETRUSOR LEAK POINT PRESSURE IN PATIENTS WITH SPINA-BIFIDA

Purpose: We report a new modification of the technique used to measure detrusor leak point pressure in patients with myelodysplasia and disc uss its clinical implications. Materials and Methods: We assessed detr usor leak point pressure during standard multichannel urodynamics in 7 7 patients with spina bifida. At leakage and in the absence of a detru sor contraction detrusor pressure is noted and the catheter is removed . With the cessation of leakage the catheter is reinserted and detruso r pressure is again noted. This cycle is repeated several times and th e average difference is noted. In 23 patients there was no identifiabl e detrusor leak point pressure. The remaining 54 patients with a detru sor leak point pressure are included in this report. Also reviewed wer e renal ultrasound studies and voiding cystourethrograms for each pati ent. Results: Three groups of patients were identified: 1 (20 patients )- detrusor leak point pressure greater than 40 and less than 40 cm. w ater with the catheter in and out, respectively; 2 (29)- detrusor leak point pressure consistently less than 40 cm. water with the catheter in and out, and 3 (5)- detrusor leak point pressure consistently great er than 40 cm, water with the catheter in and out. There was a 5% inci dence of upper tract changes in group 1 and a 40% incidence in group 3 . All patients in group 2 had normal upper tracts. Conclusions: A diff erence in upper tract changes was noted between groups 1 and 3, althou gh in both groups detrusor leak point pressure was greater than 40 cm. water using standard measurement techniques and similar rates of uppe r tract changes would have been expected. Our modification may be a mo re accurate measurement of detrusor leak point pressure. It provides a better means of identifying patients at increased risk for renal dete rioration and assessing outlet resistance.