The diagnostic accuracy of endovaginal and transperineal ultrasound for detecting anal sphincter defects: The PREDICT study

Abstract

AIM: To determine the accuracy and predictive value of transperineal (TPU) and endovaginal ultrasound (EVU) in the detection of anal sphincter defects in women with obstetric anal sphincter injuries and/or postpartum symptoms of faecal incontinence.MATERIALS AND METHODS: One hundred and sixty-five women were recruited, four women were excluded as they were seen years after their last delivery. TPU and EVU, followed by endonanal ultrasound (EAU), were performed using the B&K Viking 2400 scanner. Sensitivity and specificity, as well as predictive values with 95% confidence intervals, for detecting anal sphincter defects were calculated for EVU and TPU, using EAU as the reference standard.RESULTS: On EAU a defect was found in 42 (26%) women: 39 (93%) had an external (EAS) and 23 (55%) an internal anal sphincter (IAS) defect. Analysable images of one level of the EAS combined with an analysable IAS were available in 140 (87%) women for EVU and in 131 (81%) for TPU. The sensitivity and specificity for the detection of any defect was 48% (30e67%) and 85% (77e91%) for EVU and 64% (44e81%) and 85% (77e91%) for TPU, respectively. CONCLUSION: Although EAU using a rotating endoprobe is the validated reference standard in the identification of anal sphincter defects, it is not universally available. However while TPU and/or EVU with conventional ultrasound probes can be useful in identifying normality, for clinical purposes they are not sensitive enough to identify an underlying sphincter defect.

Predicting anal sphincter defects: the value of clinical examination and manometry

“…We have previously reported on the diagnostic accuracy of endovaginal and transperineal ultrasound for detecting anal sphincter defects [17]. We demonstrated that, when adequate images were obtained, endovaginal ultrasound had a sensitivity of 48% and a specificity of 85%, compared to 64% and 85%, respectively, for transperineal ultrasound.…”

“…All patients were recruited as part of a study [17] that aimed to identify the diagnostic accuracy of endovaginal and transperineal ultrasound for detecting anal sphincter defects. Between January 2009 and May 2010, 165 consecutive women, able to understand and read English, were prospectively recruited from the one-stop perineal clinic at Croydon (Mayday) University Hospital.…”

“…Transperineal and endovaginal ultrasound were performed first, with the patient in supine position [17], followed by perineal inspection and measurement of the length of the perineal body (from the posterior fourchette to the mid-point of the anus) using a disposable measuring tape. A vaginal examination was then performed to evaluate pelvic floor muscle strength, scored using the validated modified Oxford scale [20], which gives a score from 0 (no contraction) to 5 (very strong contraction).…”

Current applications of transperineal ultrasound in gastroenterology

“…Four ultrasonographic signs indicative of damage after repair were defined as EAS or IAS sphincter discontinuity, thickening of the EAS at the 12o'clock position, thinning of the IAS in the area of rupture in conjunction with thickening opposite the rupture site (the "halfmoon" sign), and abnormality of the mucous folds [47,48] . The PREDICT [49] study revealed that 2D TPUS had a sensitivity and specificity of 64% and 85%, respectively, for detecting sphincter defect when compared with EAUS. TPUS can be useful in identifying normality, but not sensitive enough to identify an underlying sphincter defect in women following obstetric anal sphincter injury and/or presenting postpartum with symptoms of fecal incontinence.…”

What was hot at the joint ICS and IUGA meeting Toronto, Canada, 23–27 August 2010

“…Roos et al (Abstract 39) 39 examined the sensitivity and specificity of supine transperineal (TPU) and endovaginal (EVU) ultrasound in the detection of sphincter defects (compared to endoanal ultrasound, EAU). After analysing images of 137 women with sufficient information, the authors concluded that TPU and EVU can be used if EAU is unavailable.…”