Tu1554 SMALL BOWEL CAPSULE ENDOSCOPY FOR DIAGNOSIS OF GASTRIC EMPTYING

Abstract

Gastroparesis is defined as a delay in gastric emptying in the absence of mechanical obstruction. Currently the reference standard for diagnosis is a gastric emptying study (GES). This is a long procedure (up to 4 hours) that requires intake of radiolabeled food. Many patients are unable to tolerate intake of the standard meal due to their symptoms, others are concerned about intake of radioactive isotopes. Capsule endoscopy consists of a pill size camera that visualizes the esophagus, stomach and the small bowel. Our aim was to evaluate gastric transit using a small bowel capsule endoscope and to determine normal gastric transit time. This was a retrospective review of small bowel capsule endoscopy performed in 200 consecutive outpatients at our tertiary referral clinic between 2018 and 2019. All studies were read by a single senior staff attending. Only studies performed with PillCam SB version 3 (Medtronic, Minneapolis, MN) were included. Incomplete studies, patients with altered gastric anatomy or patients with endoscopic small bowel capsule placement were excluded from the study. A total of 200 consecutive patients above the age of 18 years were reviewed. 8 patients were excluded from the study. 192 patients were included in the study, 82 males and 110 females; mean age 57 years old (range 18-89). The most common reason for capsule placement was iron deficiency anemia (115 patients). All causes of capsule placement are summarized in table 1. There was no statistically significant difference between gastric transit times based on the reason for performing the capsule study. The mean capsule gastric emptying time (gastric transit time) was 40.1 minutes (95% CI 31-48) and median time was 16.9 minutes, range from 0.03 minutes to 352.50 minutes. To calculate the extreme values which may represent pathology, we calculated a range two standard deviations above and below the median. Thus, a gastric transit time ≥154 minutes and ≤1.6 minutes may represent pathologic outcomes of delayed and rapid gastric emptying. 175/192 (91%) of patients in our cohort were between two standard deviations. Of this cohort of consecutive patients, 11 patients underwent both capsule endoscopy and gastric emptying study. Using our model on this cohort, 63% (7/11) patients had a GTT within 2 SDs and were confirmed to have a normal GES. This is the first study per our knowledge to use capsule endoscopy to evaluate gastric transit time. Since capsule endoscopy is currently not approved for diagnosis of gastroparesis, this study is limited by a lack of direct comparison to the reference standard. However, it forms a basis for further research. In patients with gastric transit time <5th or >95th percentile providers should maintain a high index of suspicion for rapid gastric emptying and gastroparesis respectively.Table 1Reasons for Capsule placementView Large Image Figure ViewerDownload Hi-res image Download (PPT)