The reasonable calculation of complete enteroscopy rate for balloon-assisted enteroscopy

In a recent article published online in Endoscopy, Möschler et al. [1] reported the results of complications and performance of double-balloon endoscopy (DBE) examinations in Germany. A remarkable aspect of the procedural data was the low rate of complete enteroscopy, which was only achieved in 23 % of patients undergoing either the oral approach alone or combined oral and anal DBE. The complete enteroscopy rate has been used as an objective parameter to evaluate the performance of balloon-assisted enteroscopy in two other studies published recently [2] [3]. There are several aspects we would like to discuss.

First, there is a wide range in the complete enteroscopy rate (18 % – 66 %) reported across large studies [3] [4] [5] [6]. Obviously many factors, such as indication and abdominal surgery history, can influence the rate of complete enteroscopy. However, what is important is that there is heterogeneity in the definition of complete enteroscopy rate. We think the definition is reasonable as a technical parameter when the complete enteroscopy rate is defined as a ratio of cases with DBE successfully passing through the entire small bowel compared with the total number of cases in which attempts to examine the entire small bowel are made, either using DBE or by some other means. Under this definition, we calculated the pooled complete enteroscopy rate of diagnostic DBE to be 44.0 % in a systematic review of 23 studies with a total of 1143 patients [7].

The role of complete enteroscopy has been well discussed in previous guidelines [8]. If the first DBE attempt achieves the final diagnosis or the procedure was undertaken to manage a definite lesion, then complete enteroscopy is of minor importance.

Second, we would like to seek clarification on the complete enteroscopy rate of 23 % quoted by Möschler et al. [1]. The authors have reported that the patients with complete enteroscopy were undergoing either the combined approaches or the oral approach alone. Given that the complete enteroscopy rate of combined approaches was 21 % and that of the oral approach alone was 2 %, the total rate would be less than 21 %. The authors have not described the specific statistical methods used to calculate the rate of 23 %.

References

• 1 Möschler O, May A, Müller M K et al. Complications in and performance of double-balloon enteroscopy (DBE): results from a large prospective DBE database in Germany.  Endoscopy. 2011;  in press
• 2 May A, Farber M, Aschmoneit I et al. Prospective multicenter trial comparing push-and-pull enteroscopy with the single- and double-balloon techniques in patients with small-bowel disorders.  Am J Gastroenterol. 2010;  105 575-581
• 3 Domagk D, Mensink P, Aktas H et al. Single- vs. double-balloon enteroscopy in small-bowel diagnostics: a randomized multicenter trial.  Endoscopy. 2011;  in press
• 4 Ohmiya N, Yano T, Yamamoto H et al. Diagnosis and treatment of obscure GI bleeding at double balloon endoscopy.  Gastrointest Endosc. 2007;  66 72-77
• 5 Heine G D, Hadithi M, Groenen M J et al. Double-balloon enteroscopy: indications, diagnostic yield, and complications in a series of 275 patients with suspected small-bowel disease.  Endoscopy. 2006;  38 42-48
• 6 Zhong J, Ma T, Zhang C et al. A retrospective study of the application on double-balloon enteroscopy in 378 patients with suspected small-bowel diseases.  Endoscopy. 2007;  39 208-215
• 7 Xin L, Liao Z, Jiang Y P. et al . Indications, detectability, positive findings, total enteroscopy, and complications of diagnostic double-balloon endoscopy: a systematic review of data over the first decade.  Gastrointest Endosc. 2011;  73 (in press)
• 8 Sidhu R, Sanders D S, Morris A J et al. Guidelines on small bowel enteroscopy and capsule endoscopy in adults.  Gut. 2008;  57 125-136