Diagnosis and treatment of small bowel pathologies remain challenging due to the long length of the small bowel. Obscure gastrointestinal (GI) bleeding with negative upper and lower GI workup, suspected inflammatory bowel disease, and suspected tumors of the small bowel often require investigations of the small bowel.
While video capsule endoscopy (VCE) and computed tomography (CT) enteroclysis (CTE) are often the initial diagnostic modalities for suspected small bowel pathologies and can provide structural information of the small bowel mucosa, biopsy or therapy for the detected pathology could not be performed with VCE or CTE. In patients who require biopsy or therapy of the detected small bowel pathology between the ligament of Treitz and ileocecal valve, deep enteroscopy would be the procedure of choice in modern clinical practice before subjecting patient to surgery.
Diagnostic and therapeutic deep enteroscopy can be performed by balloon overtube assisted enteroscopy (eg, double balloon enteroscopy (DBE), single balloon enteroscopy (SBE) or spiral overtube assisted enteroscopy (SE)). Despite the difference in equipment design of DBE, SBE, and SE, the concept for small bowel intubation by pleating the intestine over the endoscope is the same behind these techniques. Depending on the location of the small bowel pathology reported by VCE or CTE, antegrade (oral route), retrograde (anal route), or combined antegrade and retrograde deep enteroscopy for total enteroscopy can be performed. In patients with suitable anatomy, total enteroscopy by antegrade approach alone may be achieved.
DBE was introduced in 2001 and has been the most studied form of modern deep enteroscopy. In a recent systematic review of 12823 procedures, the overall diagnostic yield was found to be 68.1%. The pooled total enteroscopy rate was 44% by the combined anterograde and retrograde approach or antegrade-only approach. The pooled minor and major adverse event (eg, perforation, bleeding, pancreatitis, aspiration pneumonia) rates were 9.1% and 0.72%, respectively. Despite its clinical utility, long procedure time (usually more than 1 to 1.5 hour) and the need for 2-operators are often regarded as drawbacks of DBE. SE was subsequently designed to address this issue with the use of a spiral overtube by manual rotation for efficient small bowel intubation. When compared to balloon overtube assisted enteroscopy, the main advantage of SE is the relative reduction in procedure time. However, the total enteroscopy rate of SE is lower, mainly due to difficult overtube and endoscope passage in retrograde procedures. Adverse events with SE (eg, minor mucosal tears, perforation, etc) have been reported to be 0.3%. Because both DBE and SE have its own shortcomings, the need to further improve the current technology of deep enteroscopy has always been present.
Recently, a motorized spiral enteroscope (MSE) (Olympus Medical, Tokyo, Japan) has become available and has the potential to address the shortcomings of the DBE and SE. MSE is an enteroscope equipped with a short spiral overtube propelled by a endoscopist-controlled motor contained in the handle of the endoscope. The endoscopist controls the left-right and up-down movements by the usual manuvers while the forward or backward advancement of the enteroscope would be contolled by a foot pedal that activates the spiral overtube rotation. The basic principle of small bowel pleating over the endoscope by the use of an overtube to achieve deep small bowel intubation is similar to that of DBE and SE. During the procedure, a visual force gauge allows the operator to monitor the direction of overtube rotation and the resistance applied to the spiral overtube in the small bowel. If excessive rotational resistance is detected, the motor would be stopped automatically to avoid mucosal trauma in the intestine. The initial experience of MSE in patients with small bowel pathology and colonic pathology appears promising with a diagnostic yield of 76 - 88%, therapeutic yield of 76%, a total enteroscopy rate of 70% (combined antegrade and retrograde approaches or antegrade alone approach) and shorter procedure time (\< 40 minutes). Based on data from three studies including a total of 110 MSE procedures, no serious adverse event such as perforation has been reported. The overall adverse event rate including erosion, mucosal tear, hematoma, transient swallowing discomfort, etc, was reported to be 20% in a study with 30 patients. Despite its potential to improve the clinical management of patients with small bowel disorders, current data on the diagnostic and therapeutic utility of MSE is from expert European centers and remains limited. Investigators therefore propose this study to evaluate the utility of the MSE in patients with suspected small bowel pathology.
