STUDY OBJECTIVES:

1. Primary objective: Rate of total enteroscopy (TER) by means of NMSE or SBE with: Complete antegrade approach or combined antegrade and retrograde approach

2. Secondary objective:

   1. Technical success of anterograde and retrograde approach
   2. Procedural time (minutes)
   3. Depth of maximum insertion (cm)
   4. Diagnostic yield
   5. Therapeutic success
   6. Adverse events

1. INTRODUCTION: Small-bowel (SB) disorders remain a diagnostic and therapeutic challenge for endoscopists because of its unfavourable anatomy for endoscopy. It is difficult to perform deep enteroscopy of the long redundant lengthy small intestine by the bare endoscope, most of the time operator end up in pushing the SB rather than traveling through it. Last two decades saw a paradigm shift in the management of SB disorders with the introduction of deep enteroscopy1-4, including Double-balloon enteroscopy (DBE, Fujifilm, Tokyo, Japan), Single-balloon enteroscopy5 (SBE, Olympus Medical Systems Corporation, Tokyo, Japan), and Spiral enteroscopy6 (SE, Spiral Medical, LCC, USA). The DBE and SBE techniques have had varied results as far as depth of insertion is concerned; moreover, both are time-consuming and have difficult ergonomics for the endoscopist which are a major limiting factor. Spiral enteroscopy (SE)6 was introduced in 2007, which was two-operator technique where a spiral-shaped over-tube (Discovery Small Bowel, DSB) was used to pleat the small bowel over the enteroscope by manual rotation of the over tube. Deep endoscopic access to the small bowel with all available methods is still a complex, cumbersome, time-consuming procedure, and requires high endoscopic skills. Novel Motorized Spiral Enteroscope7 (NMSE, Olympus Medical, Tokyo, Japan) is a recent advancement in the field of enteroscopy. This enteroscope works on the same principle as that of SE and comes with an integrated user controlled motor in the handle of the enteroscope. The integrated electric motor is controlled with the help of a footswitch for rotating a short spiral over tube to pleat and un-pleat the small bowel. This would increase the possibility to accelerate the procedure, facilitate insertion, and simplify the technique with a single operator. The procedure can be done both by antegrade and retrograde approaches. Data is scarce on the utility, safety and efficacy of Novel Motorized Spiral Enteroscopy (NMSE) for evaluation in patients with suspected SBD by both the routes of examination. Also there are no comparative studies between SBE and NMSE. Hence we have planned a Randomized controlled trial to compare both modalities.
2. RATIONALE: SBE is the standard procedure used for small bowel examination at our center. SBE in prior studies has shown diagnostic yield of 40-60%5 but very low TER (0-22%)4,10, with long procedure time. NMSE on the other hand has the advantage of greater TER and high diagnostic yield with shorter procedure times and minimal adverse events. Our study on NMSE11 has shown high diagnostic yield of 70%, with TER of 61% and total procedure time of around 40min. Various studies have shown the safety and efficacy of SBE and NMSE. One recent prospective study by Beyna9 et al. using NMSE for only antegrade enteroscopy showed total enteroscopy rate (TER) of 10.6% (14/132) with technical success of 97%. Majority of patients (74.2%) underwent NMSE for suspected GI bleeding. Overall diagnostic yield was 74.2% and endotherapy was done in 68.2% patients. In our study11 on NMSE, recently published, we have shown comparable technical success using both antegrade (92.85%) and retrograde (100%) routes. There was higher total enteroscopy rate of 60.6% with antegrade route showing 31.1%.This real-world scenario analysis showed that diagnostic yield of NMSE was 70% in those who successfully underwent enteroscopy and therapeutic procedures were done in almost one fourth of patients. Till date, there are no comparative data between NMSE and Balloon assisted enteroscopy techniques. Hence, we aim to compare NMSE and SBE in Randomized controlled trial.
3. STUDY METHODS / STUDY PROCEDURE / METHODS OF ASSESSMENT: Patients presenting with symptoms and signs suggestive of small bowel disorders will be admitted and investigated as per the latest guidelines2. Patients satisfying the inclusion and exclusion criteria will be randomized in one of the two arms and will undergo either NMSE or SBE. As per the presentation and indication patients in both arms will undergo antegrade or retrograde enteroscopy. Patients undergoing antegrade enteroscopy will also undergo retrograde enteroscopy if indicated in the same sitting with the aim of total enteroscopy. Patients will be managed according to the findings and will be discharged as per the conditions. Patients will be followed up in the OPD or telephonically 1 week and after 1 month of discharge.

Inclusion Criteria:

1. Patients with small bowel disease with an indication for total enteroscopy with indeterminate imaging findings (as defined above)
2. Age > 18 years
3. Patients willing to give written consent

Exclusion Criteria:

1. Positive imaging findings (as defined)
2. Age < 18 years.
3. Contraindications for endoscopy due to comorbidities
4. Unable to provide written informed consent
5. Patients with known severe GI tract inflammation, intestinal obstruction, gastroesophageal varices that preclude a safe enteroscopy procedure
6. Coagulopathy or thrombocytopenia that couldn't be corrected by blood product transfusion
7. Pregnant patients
8. Health status American Society of Anaesthetist Classification (ASA) >3
9. Inability to tolerate sedation or general anaesthesia for any reason
10. Pediatrics patients (infants and toddlers)
11. Eosinophilic esophagitis