Traces: making sense of urodynamics testing--Part 6: Evaluation of bladder filling/ storage: bladder wall compliance and the detrusor leak point pressure

This article defines the concept of bladder wall compliance, discusses various means of measuring or assessing compliance, and reviews its clinical relevance. Based on existing evidence, low bladder wall compliance is attributable to increased detrusor muscle tone during bladder filling or changes in the viscoelastic properties of the bladder wall that impede the bladder wall's ability to stretch. While one can identify the individual components that compromise compliance, the filling CMG is only able to detect whole bladder wall compliance (for example, the combined effects of increased detrusor muscle tone and compromised viscoelastic properties of the bladder wall). From a clinical perspective, whole bladder wall compliance is divided into two categories: normal and low. Low bladder wall compliance is clinically relevant because of its potential to produce upper urinary tract distress, and there is increased risk for febrile urinary tract infections, ureterohydronephrosis, vesicoureteral reflux, renal scarring, compromised urinary tract function, and urinary incontinence because of its direct influence on the bladder outlet. It may produce pain and pressure in the patient with preserved sensations of bladder filling. Low bladder wall compliance is associated with a variety of clinically relevant disorders, including neurogenic bladder dysfunction, pelvic irradiation, interstitial cystitis, and radical prostatectomy.