Study on 3D High-Resolution Anorectal Manometry Interrater Agreement in the Evaluation of Dyssynergic Defecation Disorders.

Anorectal manometry measurements exhibit significant interrater variability. Newer techniques like 3D high-resolution anorectal manometry (3D-HRAM) have the potential to enhance diagnostic accuracy and our understanding of defecation disorders. However, the extent of interrater variability in 3D-HRAM is still unknown. Between January 2020 to April 2022, patients referred for pelvic floor physical therapy (PFPT) due to functional defecation complaints underwent 3D-HRAM testing. In a retrospective analysis, three expert raters independently evaluated the 3D-HRAM results in a blinded matter to assess interrater agreement. The evaluation also determined the level of agreement concerning dyssynergic patterns during simulated defecation. The 3D-HRAM results of 50 patients (37 females) were included. Twenty-nine patients had complaints of fecal incontinence, eleven patients had chronic constipation, and ten patients had several other complaints. There was a substantial agreement (kappa 0.612) between the raters concerning the 3D images on dyssynergic patterns during simulated defecation. Our study emphasizes the need for standardized guidelines in evaluating 3D-HRAM test results to reduce subjectivity and further improve agreement among raters. Implementing these guidelines could improve diagnostic consistency and enhance personalized treatment strategies, increasing the reliability and usefulness of 3D-HRAM testing in clinical practice.

Antibiotic Treatment foLlowing surgical drAinage of perianal abScess (ATLAS): protocol for a multicentre, double-blind, placebo-controlled, randomised trial.

INTRODUCTION: Perianal fistula is a burdening disease with an annual incidence of 6-12/100 000 in Western countries. More than 90% of crypto-glandular fistulas originate from perianal abscess. Despite adequate drainage, up to 83% recur or result in an anal fistula, the majority developing within 12 months. There is some evidence that gut-derived bacteria play a role in the development of perianal fistula. Up till now, it is not common practice to routinely administer prophylactic antibiotics to prevent anal fistula development. There is a need for a study to establish whether adding antibiotic treatment to surgical drainage of perianal abscess results in a reduction in perianal fistulas. METHODS AND ANALYSIS: This multicentre, double-blind, randomised, placebo-controlled trial investigates whether addition of antibiotics (ciprofloxacin and metronidazole) to surgical drainage of a perianal abscess is beneficial compared with surgical drainage alone. The primary outcome is the development of a perianal fistula within 1 year. Secondary outcomes include quality of life, treatment costs, need for repeated drainage, patient-reported outcomes and other clinical outcomes. Participants are recruited in one academic and seven peripheral Dutch clinics. To demonstrate a reduction of perianal fistula from 30% to 15% when treated with adjuvant antibiotics with a two-sided alpha of 0.05, a power of 80% and taking a 10% loss to follow-up percentage into account, the total sample size will be 298 participants. Data will be analysed according to the intention-to-treat principle. ETHICS AND DISSEMINATION: The study protocol has been approved by the Medical Ethics Review Committee of the Amsterdam University Medical Centers (nr. 2021_010). Written consent is obtained from each participant prior to randomisation into the study. The results of this trial will be submitted for publication in international peer-reviewed journals, presented at conferences and spread to coloproctological associations. TRIAL REGISTRATION NUMBERS: 2020-004449-35; NCT05385887.

D-2-hydroxyglutaric aciduria Type I: Functional analysis of D2HGDH missense variants.

D-2-hydroxyglutaric aciduria Type I (D-2-HGA Type I), a neurometabolic disorder with a broad clinical spectrum, is caused by recessive variants in the D2HGDH gene encoding D-2-hydroxyglutarate dehydrogenase (D-2-HGDH). We and others detected 42 potentially pathogenic variants in D2HGDH of which 31 were missense. We developed functional studies to investigate the effect of missense variants on D-2-HGDH catalytic activity. Site-directed mutagenesis was used to introduce 31 missense variants in the pCMV5-D2HGDH expression vector. The wild type and missense variants were overexpressed in HEK293 cells. D-2-HGDH enzyme activity was evaluated based on the conversion of [2 H4 ]D-2-HG to [2 H4 ]2-ketoglutarate, which was subsequently converted into [2 H4 ]L-glutamate and the latter quantified by LC-MS/MS. Eighteen variants resulted in almost complete ablation of D-2-HGDH activity and thus, should be considered pathogenic. The remaining 13 variants manifested residual activities ranging between 17% and 94% of control enzymatic activity. Our functional assay evaluating the effect of novel D2HGDH variants will be beneficial for the classification of missense variants and determination of pathogenicity.