Does the appearance of the urethral pressure profile trace correlate with the sphincter EMG findings in women with voiding dysfunction?

Abstract

Women with functional voiding dysfunction often experience a "catching" sensation when catheterising and are in general investigated with both urethral pressure profilometry (UPP) and sphincter electromyography (EMG). It is unknown whether the pattern of the UPP trace correlates with this sensation of "catching" or with sphincter EMG findings. We reviewed the database of all women with voiding dysfunction who had undergone both sphincter EMG and UPP to assess for any relationship between pattern of UPP trace and "catching" on catheterization and/or sphincter EMG findings. UPP traces were classified as smooth or pulsatile and the EMG was classified as normal or abnormal. Statistical analysis was by Chi squared test for pulsatile UPP trace as a predictor of abnormal EMG. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of a pulsatile UPP trace for predicting abnormal EMG were also determined. These patients were asked to complete a telephone interview assessing discomfort on catheterization, particularly on catheter removal ("catching"). A total of 107 women of mean age 35.8 years underwent both sphincter EMG and UPP between 2011 and 2015. There was no significant association between "catching" on catheterization and pattern of UPP. There was a significant association between the presence of a pulsatile UPP and the finding of an abnormal EMG (P < 0.0001) The PPV of pulsatile UPP for abnormal EMG was 0.82 and the NPV of pulsatile UPP for abnormal EMG was 0.74. A pulsatile UPP trace is a sensitive predictor for abnormal EMG in patients with voiding dysfunction. There is no obvious correlation between a pulsatile UPP trace and a reported "catching" sensation on catheterization.