Use of an overtube for enteroscopy--does it increase depth of insertion? A prospective study of enteroscopy with and without an overtube.

BACKGROUND AND STUDY AIMS

Although a stiffening overtube is commonly used with push enteroscopy, in the belief that this will allow increased insertion into the small intestine, there is no prospective data to support this view. The aim of this study is to prospectively study the depth of insertion into the small intestine at enteroscopy with and without an overtube.

PATIENTS AND METHODS

A total of 38 patients referred for enteroscopy were prospectively studied. Alternate enteroscopies were performed with or without an overtube; therefore 19 patients had enteroscopy with and 19 without an overtube. The groups were well matched for age, sex, indication, use of fluoroscopy, and dedicated anesthetic assistance. Depth of insertion was assessed by advancing the enteroscope as far as possible, then straightening the enteroscope until the tip began withdrawing. The difference between the straightened insertion depth and the distance from the incisors to the pylorus was recorded as the insertion depth beyond the pylorus. This was considered the major end point. Statistical analysis was performed using the Mann-Whitney test for nonparametric data.

RESULTS

The median straightened total insertion depth from the incisors was greater when enteroscopy was performed with an overtube compared with enteroscopy without an overtube (125 cm vs. 110 cm, P=0.05). The median straightened insertion depth beyond the pylorus was significantly greater with overtube use (70 cm vs. 50 cm, P = 0.01). No significant difference between the groups was observed in terms of the likelihood of significant findings at enteroscopy.

CONCLUSIONS

Use of an overtube for push enteroscopy results in significantly deeper insertion into the small intestine. Although a larger study would be needed to demonstrate an increase in diagnostic yield and to confirm the safety of overtube use, this study does provide the first objective evidence of an advantage in terms of insertion depth.