CO2 Insufflation During Double Balloon Enteroscopy

Double-balloon enteroscopy (DBE) is a novel endoscopic procedure for visualising the entire small bowel. In any GI endoscopy procedure it is mandatory to insufflate gas into the bowel to secure good visualisation. All endoscopes used for GI endoscopy provide a gas insufflation unit. Currently, air is used for this purpose in more than 90% of centres throughout the world. The use of air, however, is far from ideal to use for insufflation in GI endoscopy. After GI endoscopy, significant amounts of air are usually retained in the bowel segment inspected (5). This air has to pass the GI tract and exit physiologically through the rectum. Thus, abdominal pain and discomfort during and after the examination due to the retention of air has been shown to be very common during and after endoscopic procedures (5-9).

Carbon dioxide gas (CO2), unlike air, is rapidly absorbed from the bowel. Within minutes, several litres of CO2 can be absorbed from the GI tract. The use of CO2 has been shown to result in more comfortable examinations in both colonoscopy and flexible sigmoidoscopy in several randomised trials (6-9). In these studies, CO2 insufflation almost completely reduced procedure-related pain and discomfort.

To our knowledge, no research has been performed investigating the use of CO2 in DBE. DBE is a long-lasting procedure (mean examination time 75 minutes (4)). Large volumes of air are insufflated during the procedure, leading to significant distension of the small bowel during and after the examination.

One of the main technical difficulties in DBE is the formation of small bowel loops and scarp angels during deep intubation of the endoscope. These loops and angels are the major restriction to deep intubation of the endoscope. Loops and scarp angels are more pronounced in air-distended bowel segments.

The aim of the present study is to examine whether CO2 insufflation leads to a reduction of abdominal pain in DBE patients. Furthermore, we want to investigate if CO2 insufflation facilities a deeper intubation of the endoscope and thus a more complete examination of the small bowel mucosa.

The study is designed as a two-centre randomised controlled trial. Randomisation to the two treatment groups (CO2 or air insufflation) is performed on basis of the individual participant.