Learning Curve of Double Balloon Enteroscopy

Technical Aspects 

Outcomes 

In a multicenter study involving 6 U.S. tertiary centers with a total of 188 subjects undergoing 237 procedures, Mehdizadeh and coworkers investigated the technical details the learning curve associated with DBE.11 The performance parameters from each center’s initial 10 cases were compared with the subsequent examinations. The main outcome measurements were examination duration, depth of insertion, and findings on DBE examination. DBE was introduced by mouth in 149 (63%) cases, by rectum in 77 (33%) cases. The mean (±SD) duration was 109.1 ± 44.6 minutes for the first 10 cases and 92.4 ± 37.6 minutes for subsequent cases (P = 0.005) but did not change for rectal DBE procedures.

There was no change in mean depth of insertion, but the mean fluoroscopy time declined significantly (P = 0.025). Diagnostic or therapeutic maneuvers were performed in 64% of cases; DBE led to a diagnosis in 81 (43%) patients. One perforation occurred (0.4%). Per-rectal cases failed to reach the small bowel in 24 (31%) cases.11 The authors concluded that there was a significant decline in overall procedural time and fluoroscopy time after the initial 10 DBE cases. There was no improvement in performance parameters when DBE was performed via the rectal approach despite increased, but limited, operator experience.11

We evaluated the learning curve of DBE in 140 patients undergoing 168 DBE by a single endoscopist during a 2-year period in a prospective cohort study.10 The following performance parameters were documented prospectively: depth of insertion, duration of the procedure, fluoroscopy use, endoscopic findings, and therapeutic interventions. All procedures were performed using the diagnostic DBE. The performance parameters from the endoscopist’s initial 10, 15, and 20 cases were compared with the subsequent examinations. The procedure duration was studied in relation to procedure date. In addition, the “speed of insertion” was also investigated (cm per minute).

A total of 126 oral DBE and 42 anal DBE were performed. The mean (±SD) duration for both oral and rectal DBE was: 92.3 ± 38.6 minutes for the first 10 cases, 84.1 ± 35.5 minutes for the first 20 cases (P < 0.005), and 64.1 ± 31.2 for the subsequent cases. Both rectal and oral DBE were performed significantly faster over time. The mean depth of insertion increased and the mean fluoroscopy exposure declined significantly over time. For oral DBE, the mean insertion was 150.4 ± 15 cm for the first 10 cases, 170.4 ± 25.2 cm for the first 15 cases, and 245 ± 22.4 for the subsequent cases (Fig. 1). The mean ileal insertion for anal DBE was 30.5 ± 15.8 for the first 15 cases and 95.5 ± 22.3 for the subsequent cases (P < 0022). Deep ileal intubation via the anal route failed in 7 (17%) cases (40% of the initial 10 cases, versus 6% of the subsequent cases). There was a significant negative correlation between the procedure duration and the number of days from the endoscopists first procedure for both oral and anal procedures (P < 0001). The depth of insertion and the “speed of insertion” correlated positively between the initial days of the procedure and subsequent days.

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Figure 1. Over time, the mean duration of DBE decreased, whereas the reached distance in the small bowel increased. Expressed together in the term of insertion depth per time ([cm/min](speed)), the examination improved significantly (r = 0226; P = 0.037). (Color version of figure is available at www.techgiendoscopy.com.)

Diagnostic or therapeutic interventions were performed in 86% of cases; DBE led to a diagnosis or therapeutic intervention in 111 (79%) patients. Only 8% of patients had prior capsule endoscopy. A total of 3 complications occurred (none severe): bleeding after polypectomy (n = 1), ileus (n = 1), and respiratory depression (n = 1).

Conclusions 

Both we and Mehdizadeh and coworkers demonstrated that there was a significant improvement in DBE performance over time, including increased depth of insertion, decline in procedural time, “speed of insertion,” and decreased use of fluoroscopy for both oral and anal DBE procedures. These parameters improved significantly after the initial 10 oral (15 anal) cases. Although more data of additional centers are needed, we believe that knowledge of these technical data may be helpful for endoscopists planning to perform DBE, to plan the case load in individual endoscopy units, and for establishing baselines for DBE skill certification. Future studies using the therapeutic DBE and comparing the learning curve using both types of endoscopy may improve our knowledge on the learning curve of DBE. Nonetheless, it appears that a significant amount of time and a minimum of 10 to 15 procedures are required to acquire the skills necessary to perform DBE.