What other endoscopic tests are available to evaluate the small bowel in patients with obscure GI bleeding?
Various “long endoscope” endoscopy tests permit diagnosis and potential treatment.
Push enteroscopy
- Push enteroscopy uses an enteroscope that is similar, but substantially longer than a standard UGI endoscope.
- The longer enteroscope allows intubation more distally, typically into the proximal jejunum, approximately 50 cm beyond the ligament of Treitz.
Spiral enteroscopy
- Spiral enteroscopy uses a 118-cm long overtube with a soft, raised, spiral helix at its distal end (Spirus Medical Inc., Stoughton, MA) that is placed over a long enteroscope.
- The overtube is affixed to the enteroscope via a coupling device that permits rotation of the overtube.
- The spiral ridge of the overtube engages the small bowel plicae circulares (folds) during clockwise rotation like a screw into wood.
- The enteroscope is advanced by rotating the overtube clockwise, which pleats the small bowel onto the overtube.
- The most common complication is self-limited mucosal trauma from spiraling over mucosal folds.
- There is a low rate of major complications of 0.4%, including a 0.3% rate of GI perforations. Spiral enteroscopy is not widely available.
Double-balloon enteroscopy
- Double-balloon enteroscopy consists of a 200-cm long enteroscope with a latex balloon at its tip, and a 145-cm long soft overtube with another latex balloon at its tip, and pumps to inflate both balloons.
- The enteroscope is advanced during repetitive cycles of inflation and deflation of the individual balloons coupled with alternating advancement of the enteroscope or overtube.
- The diagnostic yield for the indication of obscure bleeding ranges from 40% to 80%.
- The rate of major complications is approximately 0.7%, with a 0.4% rate of GI perforation.
Single-balloon enteroscopy
- Single-balloon enteroscopy uses a 140-cm long overtube and a 200-cm long enteroscope.
- The overtube is equipped with an inflatable balloon at its tip to aid in endoscope advancement through the small bowel by pleating of small bowel on the overtube.
- The average depth of small bowel insertion ranges from 150 to 250 cm.
- Single-balloon enteroscopy has a yield somewhat lower than double-balloon enteroscopy, with a diagnostic yield of 40% to 65%.
- Complications include abdominal pain, pyrexia, mucosal tears, aspiration pneumonia, cardiovascular events, and perforation. The rate of GI perforation is approximately 0.4%.
