Improving Small Bowel Capsule Endoscopy VisualizationJuly 26, 2022
A shorter time lapse between ingestion of last laxative dose and small bowel capsule endoscopy (SBCE) was associated with better visualization of the mucosa, according to a systematic review and meta-analysis.
In a pooled analysis involving over 2,300 patients, purgative preparations were linked to a 15% improvement in adequate small bowel cleansing (pooled rate difference [RD] 0.15) compared with fasting alone, and this result was confirmed when evaluating only randomized controlled trials (RD 0.18, 95% CI 0.11-0.25), reported Clelia Marmo, MD, of the Universita Cattolica del Sacro Cuore in Rome, and colleagues in Digestive and Liver Disease.
Furthermore, receiving polyethylene glycol (PEG) after ingestion of the capsule on the same day was associated with the highest rate of adequate small bowel cleansing (RD 0.33, 95% CI 0.21-0.45) compared with fasting alone, especially within shorter time frames:
- 1-6 hours before: RD 0.28, 95% CI 0.17-0.36
- 6-12 hours before: RD 0.21, 95% CI 0.08-0.33
This did not reach significance for time frames of 12 hours or longer (RD 0.05, 95% CI -0.02 to 0.12), the authors noted.
“Timing of solution intake was the main factor that independently influenced small bowel cleansing,” they wrote.
“It is well known that, in bowel preparation before colonoscopy, split or same day regimens have been shown to be superior to day-before regimens in achieving satisfactory bowel cleansing rates,” they continued. “In the everyday clinical practice, we should use low volume preparations scheduled to be closer to the capsule ingestion.”
In other results from the study, an analysis only including randomized trials showed a 6% improvement in positive findings with a purgative solution (RD 0.06, 95% CI 0.00-0.12).
SBCE is widely used in clinical practice to diagnose small bowel disorders, Marmo’s group noted. Despite this, the optimal timing of small bowel preparation before SBCE remains uncertain.
European guidelines suggest the use of 2 L of PEG and simethicone before examination, “while North American guidelines do not recommend a specific kind or dose of bowel cleansing, despite recognizing that the use of a bowel preparation for SBCE improves mucosal visualization,” they wrote.
For this study, Marmo and colleagues examined data on 2,372 patients (mean age 54, 47.4% men) who underwent small bowel cleansing to prepare for SBCE across 17 studies that were published up to Dec. 26, 2021. After searching four databases (the Cochrane Central Register of Controlled Trials, Embase, Medline, and ClinicalTrials.gov), the researchers included six observational and 11 randomized trials that compared at least two types of preparation.
Studies that evaluated unconventional types of preparation or took a special interest in particular subgroups were excluded. Overall, studies showed significant publication bias, but this bias disappeared when analyzing only randomized trials.
Common SBCE indications included iron deficiency anemia (29.2%), suspected small bowel bleeding (28.8%), or suspected/known Crohn’s disease (11%).
Notably, 89% of patients underwent a complete small bowel exam, and the number needed to treat was 6 (95% CI 4.76-7.14).
Marmo and colleagues noted that diagnostic yield values of the studies limited the clinical information that can be obtained during SBCE, such as size, number, or type of lesions seen. Additionally, diagnostic yield could have been affected by ecological bias and the heterogeneity of patient populations, potentially explaining the poor difference in positive findings.
Marmo and co-authors reported no conflicts of interest.