Does the insertion depth in push enteroscopy depend on the working length of the enteroscope?

Background and Study Aims: Using push enteroscopy, the small bowel can only be investigated in part. This preliminary prospective randomized study examined whether increasing the length of the enteroscope can have a beneficial effect on the insertion depth. Patients and Methods: Between August 1999 and December 1999, 28 consecutive patients were investigated using push enteroscopy and were randomly assigned to two groups. One group was investigated using the Olympus push enteroscope SIF-100 (working length 2200 mm). In the other group, the Olympus push enteroscope SIF-Q140 (working length 2500mm) was used. All investigations were carried out using an overtube. The insertion depth was estimated by counting the folds in the small bowel. In addition, the insertion length was estimated in centimeters by withdrawing the instrument to the pylorus after straightening. Results: The two groups were comparable in terms of age, sex distribution, indication for enteroscopy, investigation time, and pathological findings. There were no significant differences in the insertion length between the two types of instrument. With the SIF-100, the median number of folds was 95 (range 30 - 213) and the insertion length was 72.5 cm (range 40 - 110 cm); and with the SIF-Q140, the median number of folds was 79 (range 18-203) and the insertion length was 70.0cm (range 20-140 cm). Conclusions: As there was no significant difference in the insertion depth between the shorter instrument (Olympus SIF-100) and the longer one (Olympus SIF-Q140), it can be concluded from this preliminary study that there is no advantage in using a longer enteroscope. To document a significant difference, further studies with a larger numbers of patients would be necessary.