Alternative Methods for Small Bowel Investigations
Prior to the invention of VCE, other methods, such as radiological investigations or other modalities of endoscopy examining the small bowel were in use. One of the more important radiological investigations is called barium follow-through (BFT), which is not as sensitive as VCE in finding small lesions, especially in cases of obscure GI bleeding. Air barium enteroclysis is more accurate than BFT for superficial ulcers, but it is more technically difficult, and requires a radiologist with greater expertise.
Other older alternative endoscopies for VCE included push enteroscopy, in which there is an extra 2–2.7 m endoscope to view the small intestine beyond the standard esophagogastroduodenoscopy (EGD). Besides that, push enteroscopy allows the visualization of small lesions, and therapeutic interventions and performing biopsies are also possible. Other older and less commonly used alternatives for VCE are double-balloon endoscopy (DBE) and intraoperative endoscopy, which are generally more invasive in comparison to conventional endoscopies and may cause significant patient discomfort. In addition, most of these older endoscopies require admission to hospital and more sedation, possibly even general anesthesia.
A meta-analysis of ten studies comparing VCE and DBE showed similar diagnostic yields in patients with obscure GI bleeding (62 and 56%, respectively; p = 0.16). However, the diagnostic yield of DBE is significantly higher when performed in patients with a positive VCE.
Several new endoscopic and non-endoscopic techniques are also becoming available, including device-assisted enteroscopy, computed tomography (CT)- and MRI-enteroclysis/enterography. CT scans and MRI are particularly useful for examining small bowel wall thickness, masses and strictures. Patients tolerate CT-enteroclysis better than other types of enteroclysis. The utility of these newer diagnostic/therapeutic techniques are rapidly evolving, but their discussion is beyond the scope of this review. However, studies suggest that these modalities can each have a complementary role.
Expert Rev Gastroenterol Hepatol. 2013;7(4):323-329. © 2013 Expert Reviews Ltd.