Anorectal manometry to diagnose dyssynergic defecation: Systematic review and meta‐analysis of diagnostic test accuracy

• Published in: Neurogastroenterology and motility 2021-11, Vol.33 (11), p.e14137-n/a
• Main Authors: Ortengren, Alexandra R., Ramkissoon, Resham A., Chey, William D., Baker, Jason R., Staller, Kyle, Iturrino, Johanna, Shah, Eric D.
• Format: Article
• Language: English
• Subjects: Accuracy; Anorectal; Ataxia - complications; Ataxia - diagnosis; balloon expulsion testing; Constipation; Constipation - complications; Constipation - diagnosis; Defecation; Defecography; diagnostic test performance; Diagnostic tests; dyssynergic defecation; Humans; Manometry; Meta-analysis; outlet dysfunction constipation; Rectal Diseases - complications; Rectal Diseases - diagnosis; Sensitivity and Specificity; Systematic review
• ISSN: 1350-1925; 1365-2982
• DOI: 10.1111/nmo.14137

Background Chronic constipation is a common condition, and dyssynergic defecation underlies up to 40% of cases. Anorectal manometry is recommended to assess for dyssynergic defecation among chronically constipated patients but remains poorly standardized. We aimed to evaluate the diagnostic accuracy of anorectal manometry and determine optimal testing parameters. Methods We performed a systematic review with meta‐analysis of diagnostic test accuracy including cohort studies of chronically constipated patients and case–control studies of patients with dyssynergic defecation or healthy controls. Meta‐analysis was performed to determine summary sensitivity, specificity, and area under the curve (AUC) with 95% confidence intervals (CI). Key Results A total of 15 studies comprising 2140 patients were included. Including all studies (estimating optimal diagnostic accuracy), the AUC was 0.78 [95% CI 0.72–0.82], summary sensitivity was 79% [61%–90%], and summary specificity was 64% [44%–79%] to diagnose dyssynergic defecation. In cohort studies only (estimating real‐world diagnostic accuracy), the AUC was 0.72 [0.66–0.77], summary sensitivity was 86% [64%–95%], and summary specificity was 49% [30%–68%]. Employing three consecutive simulated defecation attempts improved sensitivity to 94%. A fourth simulated defecation maneuver with air insufflation may improve accuracy. Measuring anorectal pressures to identify complex dyssynergic patterns did not improve real‐world diagnostic accuracy estimates over anal pressure measurement alone. Choice of manometry system did not impact diagnostic accuracy. Conclusions & Inferences Following the current iteration of the London consensus protocol (three simulated defecation attempts measuring anal relaxation), the role of anorectal manometry in evaluating dyssynergic defecation appears limited. Future iterations of this protocol may improve diagnostic accuracy. In a systematic review with meta‐analysis of diagnostic test accuracy, anorectal manometry was sensitive but not specific to detect dyssynergic defecation. Future iterations of the London consensus protocol may improve diagnostic accuracy.