Are urodynamic studies really needed during bladder augmentation follow-up?

Abstract 

Objective

We assessed clinical and urodynamic outcomes, over a minimum 10-year follow-up period, of neuropathic bladder patients treated with a bladder augmentation (BA) to determine if periodic urodynamic studies are needed.

Material and methods

Thirty-two patients with poorly compliant bladders underwent BA at a mean age of 11 years (2.5–18). Mean follow-up was 12 years (10–14.5) and mean patient age at the end of the study was 22 years (12.2–33). During follow-up all patients were controlled at regular intervals with urinary tract imaging, serum electrolyte and creatinine levels, cystoscopy and urodynamic studies. Preoperative, 1-year post-BA and latest urodynamic studies results were compared.

Results

Urodynamic studies at 1-year post-BA showed a significant increase in bladder capacity and a decrease in end-filling detrusor pressure compared with preoperative values (396 vs 106ml; 10 vs 50cmH₂O, P<0.0001). The increase in bladder capacity was more significant at the end of the study than after 1 year (507.8 vs 396ml, P<0.002). Thirteen patients had phasic contractions after 1 year and 11 at the end (not significant, NS), and these contractions were more frequent with colon than with ileum (NS). At the end of follow-up, phasic contraction pressure had decreased while trigger volume had increased (35 vs 28cmH₂O; 247 vs 353ml, NS). All patients are dry and have normal renal function, except one who had mild renal insufficiency before BA.

Conclusion

BA improves bladder capacity and pressure, and these changes are maintained over time (although phasic contractions do not disappear). Repeated urodynamic studies are only necessary when upper urinary tract dilatation or incontinence does not improve.

Keywords: Bladder augmentation, Enterocystoplasty, Neuropathic bladder, Urodynamic studies