Detrusor after-contraction: a new insight

Abstract

Aims:Detrusor after-contractions (DAC) are non-common in adults. Both definition (nothing in ICS reports) and significance (artefact, link with detrusor overactivity (DO) or bladder outlet obstruction (BOO)) remain discussed. Our purpose was to carry out an analysis of the urodynamic parameters during voidings with DAC and, using the VBN model, to simulate pathophysiological conditions able to explain both voiding phase and DAC.Materials and Methods:From large urodynamic database of patients referred for evaluation of lower urinary tract dysfunction, DAC were observed in 60 patients (5.7%). Criteria for DAC were post-void residual <30mL and increase of detrusor pressure >10cmH2O. VBN model was used for analysis of both pressure and flow curves, and simulations of pathophysiological conditions.Results:Onset of DAC (ODAC) occurred when Q=7.3±5.7mL/s and bladder volume=17.9±15.4mL. Urgency-frequency syndrome and urodynamic diagnosis of DO were the more frequent scenarios associated with DAC. ODAC was associated to an inversion of the slope of detrusor pressure curve without any perturbation in flow curve. Among tested pathophysiological hypothesis (great, abnormal, detrusor force, sphincter contraction), none allowed restoring all recorded curves (flow rate, voiding pressure and DAC).Conclusion:No urodynamic characteristic of the first part of voiding is an index of occurrence of DAC. ODAC is a significant phenomenon linked with the bladder collapse. DAC is not associated with BOO but more probably with DO and appears as the result of local conditions in an almost empty bladder (concentration of stresses around a transducer); thus DAC seems of weak clinical significance.

Re: Detrusor after‐contraction on ambulatory urodynamics in symptomatic women

“…I was very interested by the article of Veeratterapillay et al, 1 because it was published at the same time as an article written by my research team. 2 I agree with their finding that detrusor after-contraction (DAC) was probably associated with detrusor overactivity (DO). In our study, urodynamic diagnosis of DO was found in 54% of women without neurological disease or stage >2 prolapse; DO was phasic in 36%.…”

ICS‐SUFU standard: Theory, terms, and recommendations for pressure‐flow studies performance, analysis, and reporting. Part 2: Analysis of PFS, reporting, and diagnosis

“…The feature after‐contraction is defined in ICS‐GUP16 including a comment on the relevance of postvoiding cough checks 4 . The relevance of after‐contraction has not been clearly established 52,53 . The WG does not recommend about relevance of after contractions in PFS analysis e.g., for diagnosis of voiding dysfunction or the quantification of DVC or UR.…”

“…4 The relevance of after-contraction has not been clearly established. 52,53 The WG does not recommend about relevance of after contractions in PFS analysis e.g., for diagnosis of voiding dysfunction or the quantification of DVC or UR. After-contractions will not be visible on a PFS-plot because Q is zero during this contraction.…”