Study design
Study population Consecutive patients with suspected Crohn's disease requiring small bowel endoscopy based on abnormal imaging or capsule endoscopy shall be recruited.
Study settings:
The proposed study would be conducted in a high volume tertiary GI centre (Asian Institute of Gastroenterology) performing nearly more than 500 SBE/NMSE procedures per year with an well established inflammatory bowel disease (IBD) registry with more than 7000 IBD patients under follow up.
The study is approved by the institutional review boards and ethics committee. Written informed consent would be taken from each participants and the study would conform to the 1975 Declaration of Helsinki ethical guidelines.
Data collection A survey administration software (google forms) would be used to collect the participant data \[age, sex, comorbidities, clinical features, smoking status, history of intestinal resection, type of DAE, indication of DAE, CT/MRE location and characteristic of lesions, capsule endoscopy findings, depth of insertion, time taken for the procedure, total enteroscopy rates, enteroscopy finding details, cause of failure if any, DAE findings, histopathology details, impact on management, adverse events, hospital stay and any therapeutic procedure performed e.g. endoscopic balloon dilation (EBD) with details\]. Follow-up details for newly diagnosed CD cases would be collected via physical visit or telephonic communication.
Technique and instruments Single balloon enteroscopy: All SBE procedures will be performed with single balloon video-enteroscope (Olympus Medical Systems, Tokyo, Japan) under monitored anaesthesia (deep sedation with propofol). Initially antegrade/retrograde enteroscopy would be performed based on anticipated location in CT failing which enteroscopy would be done from opposite route to reach the lesion. If the desired lesion is not reached via antegrade/retrograde route, hemoclips would be applied or tattooing would be done followed by enteroscopy from opposite direction on the same day under the same anaesthesia using the same overtube. Fluoroscopy would be used in select cases with anticipated therapeutic procedure. All the procedures were done after minimum of 8 hours of fasting and bowel preparation was given with 4 litres of polyethylene glycol (PEG) for all. Duration of procedure would be calculated from the time of introduction of the enteroscope to time of removal. The depth of insertion would be measured using the push and pull technique. If the desired lesion is not reached by a single route and was deemed possible to reach by the other route, the area of maximal insertion shall be marked by India ink tattooing or hemoclip application followed by completion of bidirectional enteroscopy on the same or next working day.
Novel motorized spiral enteroscopy: All the NMSE (Olympus Medical Systems Corporation, Tokyo, Japan) procedures would be performed under general anaesthesia with nasotracheal intubation under fluoroscopic guidance. Four litres of PEG was given to all patients with at least 8 hours of fasting prior to NMSE. Initially antegrade enteroscopy would be performed failing which retrograde enteroscopy would be done to reach the lesion. If the desired lesion is not reached via antegrade route, hemoclips would be applied or tattooing would be done followed by retrograde enteroscopy on the same day under the same anesthesia using the same overtube. The time of procedure will be calculated from insertion of NMSE to its withdrawal. The depth of insertion would be measured by sequential withdrawal technique as described earlier.
All the enteroscopy procedures were performed by four small bowel endoscopists all of whom have performed at least 200 deep enteroscopy. At least 8 biopsies were taken from area of interest during DAE and sent for histopathological analysis. In selected cases, additional samples were sent for detection of tubercular bacilli using mycobacterium tuberculosis (MTB)-polymerase chain reaction (PCR) if clinically tuberculosis was considered as differential diagnosis. Histopathological findings were recorded under the following headings for diagnosing CD: chronic inflammation, architectural distortion and presence of granulomas.
Definitions:
Technical success shall be defined as enteroscope introduction beyond duodenojejunal (DJ) flexure or ileocecal valve via antegrade and retrograde route respectively. The diagnostic yield with DAE shall be defined as the percentage of procedures which confirmed/excluded lesions found on prior cross-sectional imaging (CTE/MRE) or found new/alternate diagnosis explaining the clinical condition. Depth of maximal insertion (DMI) will be defined as the point beyond which DAE advancement was not feasible. Major adverse events are perforation, pancreatitis, bleeding requiring transfusion or procedure related hospitalization. Minor adverse events are superficial mucosal injury, self limiting sore throat/nausea/vomiting, minor bleeding (without need for blood transfusion) or pain abdomen (not requiring hospital admission). Total enteroscopy will be defined as examination of small bowel from DJ flexure to ileocecal valve. Total enteroscopy would be achieved by either uni-directional (antegrade or retrograde route) or bi-directional enteroscopy (using both antegrade and retrograde route). The histopathological diagnosis of CD will be confirmed if non-caseating micro-granulomas are found with either of both of the other two histological features (chronic inflammation and architectural distortion) and alternate diagnosis like small bowel tuberculosis is ruled out based on clinical, radiologic and other relevant findings. Presence of both chronic inflammation and architectural distortion, non-caseating granuloma/chronic inflammation/ architectural distortion alone will be considered suggestive of CD in the appropriate clinical settings.
Sample size
Based on the pilot study by the investigators, diagnostic yield for deep enteroscopy with NMSE and SBE (97.8% and 83.2% respectively, the estimated sample size is total 124 (62 in each group) keeping type 1 error as 0.05 and power as 80%.
Randomisation
Randomisation will be done based on web based randomisation services
Timeline: 2 years Recruitment of 124 suspected CD patients requiring small bowel evaluation over maximum 2 years.
Patient privacy An organised database for the purpose of this study will be formed based on google form with anonymised data set (i.e. name, address, and full post code will be removed, together with any other information which, in conjunction with other data held by or disclosed to the recipient, could identify the patient) which would be entered by clinical research assistant.
