Reply to Dr. Matshushita et al.

We thank Dr. Matshushita and his colleagues for their interest in our article on complications and double balloon enteroscopy (DBE). In this article we conclude that diagnostic DBE is a relatively safe procedure with an overall complication rate of 0.8 % [1]. Acute pancreatitis was found to be the most common complication after diagnostic DBE (0.3 %). All cases of acute pancreatitis after diagnostic DBE procedures presented in our article occurred after peroral procedures.

The pathophysiologic cause of DBE-related pancreatitis is unclear. Two possible theories about the cause of post-DBE pancreatitis co-exist: 1) mechanical strain by the stretch of the push-and-pull technique, as presented by Honda et al. [2] and Matshushita et al. [3], and 2) reflux of duodenal contents into the pancreatic duct by increased intraluminal pressure caused by inflation of both balloons in the area of the ampulla of Vater, as presented by the Rotterdam group [4]. Both theories are supported with little evidence. The “mechanical strain” theory is supported by the fact that in five patients (out of eight) the pancreatitis was located in the body and/or tail of the pancreas. In only two patients was the whole pancreas involved, and in one patient the pancreatitis was confined to the head of the pancreas (combining the presented published cases of postdiagnostic DBE pancreatitis in the literature to date [1] [2] [3] [4]). The “intraluminal pressure” theory is supported by the fact that after adjusting the insertion technique of the DBE endoscope by inflation of the balloons only after passing the ligament of Treitz, no clinically evident pancreatitis has been experienced in our, or other, center(s) so far. In theory, the “mechanical strain” theory would give rise to localized pancreatitis, and the “intraluminal pressure” theory to involvement of the entire pancreas. Furthermore, the first theory is based on only small numbers of cases, and the second theory can be influenced by the learning curve of performing DBE procedures.

The complication risk after therapeutic interventions, as presented in our article, was relatively high (4.3 %), especially compared with therapeutic colonoscopy [1]. We agree on the comments made by Matshushita et al. concerning the adjustments of endoscopic intervention techniques to improve the safety of therapeutic DBE procedures. Using an adjustable snare might prevent bleeding complications after polypectomy during DBE. Submucosal injection (as advocated by May et al. [5]) or injection of the stalk of the polyp using saline (with or without adrenalin) may be another adjustment to reduce the postpolypectomy bleeding rate after polypectomy during DBE procedures. Submucosal injection of saline might, in theory, be useful to prevent complications after argon plasma coagulation treatment in patients with angiodysplasia in the small bowel. All mentioned adjustments have to prove their feasibility and potential for preventing complications after therapeutic DBE procedures in future reports/studies.

Competing interests: None

References

• 1 Mensink P BF, Haringsma J, Kucharzik T. et al . Complications of double balloon enteroscopy: a multicenter survey.  Endoscopy. 2007;  39 613-615
• 2 Honda K, Itaba S, Mizutani T. et al . An increase in the serum amylase level in patients after peroral double-balloon enteroscopy: an association with the development of pancreatitis.  Endoscopy. 2006;  38 1040-1043
• 3 Matshushita M, Shimatani M, Uchida K. et al . Mechanism of acute pancreatitis after peroral double-balloon enteroscopy.  Endoscopy. 2007;  39 480
• 4 Groenen M J, Moreels T G, Orlent H. et al . Acute pancreatitis after double-balloon enteroscopy: an old pathogenetic theory revisited as a result of using a new endoscopic tool.  Endoscopy. 2006;  38 82-85
• 5 May A, Nachbar L, Pohl J, Ell C. Endoscopic interventions in the small bowel using double balloon enteroscopy: feasibility and limitations.  Am J Gastroenterol. 2007;  102 527-535