Effect of Water Exchange Method on Intubation Depth and Diagnostic Yield in Patients Undergoing Single-balloon Enteroscopy: a Prospective, Randomized, Controlled, Patient-blind Trial.

Enteroscopy, including double balloon enteroscopy (DBE), single balloon enteroscopy (SBE) and spiral enteroscopy (SE) currently, have shown good performances in small bowel diagnostics and seem to be useful in the clinical routine. However, enteroscopy is a time-consuming procedure. During common practice, large volumes of air need to be insufflated for good visualization. It leads to significant distention of the small bowel during the examination, which makes further intubation more technically challenging because of the formation of distended bowel loops and acute angulations and limits the maximal intubation length. According to the published data, the oral insertion depth of different kinds of enteroscopy is limited to approximately 240 cm. The total examination rate range form 18% to 86% for DBE and 0% to 11% for SBE.

It is thought that the intubation depth in small bowel determines the diagnostic yield and the following treatment. The deeper the enteroscopy is advanced into the small bowel, the more lesions may be found and treated. In order to improve the intubation depth of balloon enteroscopy, several methods, such as carbon dioxide insufflation and decompression side tube-equipped device, have been tried and showed positive effects. CO2 insufflation could also reduce severe pain during DBE and residual gas retention after the procedure because of rapid absorption. However, it is not known how much CO2 insufflation can decrease the distention of small bowel and the formation of bowel loops.

Recently, the use of water infusion in lieu of air insufflation has been shown to facilitate completion of colonoscopy, even in potentially difficult patients with prior abdominal or pelvic surgery. Water exchange method obviates excessive lengthening of the colon and the formation of acute angulation, which may cause less pain and easier intubation during scope insertion. Recently, water exchange method was also tried in two patients undergoing SBE via antegrade route in our center. Distal ileum 8cm near to ICV and the cecum was reached respectively (unpublished data), indicating water exchange be a useful method for deep intubation of SBE.

Here a prospective, randomized, controlled trial was designed to investigate whether, compared with CO2 insufflation method, water exchange method could increase the intubation depth and diagnostic yield in patients undergoing SBE.