Journal Club Do Oro-anal Transit Markers Predict Which Children Would Benefit From Colonic Manometry Studies ST8 paediatric trainee Sheffield Children’s Hospital

Background Chronic constipation -25% of Gastro referrals Evaluation of colonic motility useful when laxatives/ behavior modification fails Slow oro-anal transit time(OTT) found in about half of these children Most of these children have motor abnormalities as identified by colonic manometry studies

Aim of the study To correlate OTT to CM studies in children with constipation JPGN Feb 2012 Do Oro-anal Transit Markers Predict Which Children would Benefit From Colonic Manometry Studies?

Methods Retrospective study Records of children with constipation who underwent OTT and CM studies reviewed OTT study performed using gelatin capsule with 24 markers Abd Xray taken after day 3 and day 5 On day 5, on X ray, number of markers counted in 3 regions-left colon, right colon and recto-sigmoid >6 markers/region of colon on day 5 above rectum significant.

Methods-contd CM study Tip of catheter placed beyond the hepatic flexure, proximal site in rectum Perfused with 0.45% saline at 0.15 ml/min Baseline colonic contractions recorded for 1 hr Mixed solid/liquid meal given. Contractions recorded for 1 hr postprandial period Bisacodyl enema infused,another hr contractions recorded

Methods contd Normal- high amplitude contractions of 60mm of Hg >10sec(HAPC) in aboral fashion Non propagative if contractions low amp/absent the presence of a gastro-colonic response, a 20% increase in the postprandial motility.

Clinical characteristics Age at time of testing/sex Symptoms Duration of symptoms Post test therapy-medication escalation/surgery Stooling response- improved,unchanged,worsened,unknown

Clinical characteristics of children with slow and normal OTT

Results Example of slow oro-anal transit time (OTT) study and colon manometry (CM) tracings. A, OTT demonstrates retention of >8 markers at 5 days post-capsule ingestion and markers are scattered throughout the left colon. B, Normal CM tracing shows high-amplitude propagating contractions (HAPC) propagating from the cecum to distal sigmoid colon. C, CMtracing in subject with x-ray from panel A that shows an HAPC but with arrest at the distal transverse colon.

Results No statistical difference in clinical characteristics between normal and slow transit time

Findings of OTT testing 5 children had normal OTT 4 had no markers and 5 th - had 3 markers in rectum 19 children had slow OTT  5 had markers that failed to progress beyond right colon  7 had markers that failed to progress beyond left colon  7 had diffuse distribution of markers.

Findings of Colonic manometry testing Fifteen had normal study and 9 had abnormal study no HAPCs in response to bisacodyl (3), segmental arrest of the HAPCs at the right colon (4), and segmental arrest of HAPCs at the splenic flexure (2).

Correlation of OTT and CM study All 5 with normal OTT had normal CM study Of the 19 abnormal ones 5 had right sided markers 2 had normal CM 3 had left sided colonic pseudo obs (2 myopathic,1neuropathic)

Correlation of OTT and CM study 7 left sided delay 3 normal CM 1 total cpo(myopathic) 3 left sided cpo(2 myo,one neuropathic) 7 diffuse distribution 5 normal 2 cpo(1 myo,1 neuro)

Outcome on follow up-Normal OTT Outcome Intervention study 3 normal OTT,3 normal CM 1 behavior 1 surgical Improvement 1 enhanced medical therapy No improvement

Outcome of Abnormal OTT-normal CM 8 normal CM 2 behaviour One surgical 3 improved 5 medical 3 improved 2 worsened

Outcome of abnormal OTT-abnormal CM 6 abnormal CM 0 Behaviour 1 medical 1 medical- unchanged 5 surgery Improved

Conclusion Assessment of oro-anal transit time is important in chronic constipation Helps guide us to those who need CM A normal OTT precludes use of CM,so long as a larger prospective study proves the same! Until larger prospective study completed, colon motility study should be used in refractory constipation

Conclusion OTT is not a substitute for CM testing for neuromuscular function.

Critical appraisal Small Retrospective study!

Critical appraisal A Are the results of the study valid? B What are the results? C Will the results help me and my patients/population?

Are the results of the study valid? 1.Was there a clear question for the study to address? Population Test Setting Outcomes 2.Was there a comparison with an appropriate reference standard?

Detailed questions 3. Did all patients get the diagnostic test and the reference standard? 4. Could the results of the test of interest have been influenced by the results of the reference standard? Was there blinding? Were the tests performed independently?

Questions contd 5. Is the disease status of the tested population clearly described? - Presenting symptoms - disease stage or severity - co-morbidity - differential diagnoses

Questions contd 6. Were the methods for performing the test described in sufficient detail? ? A protocol followed

Questions contd What are the results? Are the sensitivity and specificity and/or likelihood ratios presented? - Are the results presented in such a way that we can work them out?

Questions 8.How sure are we about these results? - Could they have occurred by chance? - Are there confidence limits? - What are they

Questions C/ Will the results help me and my patients/population? 9 Can the results be applied to your patients the population of interest? Such as age, sex, ethnicity

Questions 10 Can the test be applied to your patient or population of interest? Resources availability of expertise Current practise

Questions 11 Were all outcomes important to the individual or population considered? Will it change patient management? 12 What would be the impact of using this test on your patients/population?