A novel three-dimensional dynamic anorectal ultrasonography technique for the assessment of perineal descent, compared with defaecography

Aim The purpose of the study was to describe a novel three‐dimensional dynamic anorectal ultrasonography technique (dynamic 3‐DAUS) for assessment of perineal descent (PD) and establishment of normal range values, comparing it with defaecography. Secondarily, the study compares the ability of the two techniques to identify various pelvic floor dysfunctions. Method A prospective study was undertaken in 29 women (mean age 43 years) with obstructed defecation disorder. All patients underwent defaecography and dynamic 3‐DAUS and the results were compared. Lee kappa coefficients (K) were used. Results On defaecography, PD > 3 cm was detected in 12 patients. On dynamic 3‐DAUS, 10 of these patients had PD > 2.5 cm. Seventeen had normal PD on defaecography and PD ≤ 2.5 cm on dynamic 3‐DAUS (K 0.85). Normal relaxation was observed in 10 patients and anismus in 14 with both techniques (K 0.65). Both techniques identified five patients without rectocele, two with grade I rectocele (K 0.89 and 1.00, respectively) and 10 with grade II and nine with grade III (K 0.72 and 0.77, respectively). Rectal intussusception was identified in six patients on defaecography. These were confirmed on dynamic 3‐DAUS in addition to the identification of another seven cases indicating moderate agreement (K 0.46). Enterocele/sigmoidocele grade III was identified in one patient with both techniques, indicating substantial agreement (K 0.65). Conclusion Dynamic 3‐DAUS was shown to be a reliable technique for the assessment of PD and pelvic floor dysfunctions, identifying all disorders and confirming findings from defaecography.