Currently, there are limited options for detecting gastrointestinal motility abnormalities. The most definitive current evaluation is antroduodenal manometry (ADM) which remains restricted to a few specialized pediatric centers (coming soon to Children’s Center for Digestive Healthcare/Children’s Healthcare of Atlanta –Fall 2013). And, of course, in many cases of defined motility disorders there are limited available treatments. This situation has prompted one of my colleagues to state that motility testing is like getting the license plate of the bus that hit you.
A wireless motility capsule has the potential to facilitate motility testing. A recent study explores it use in 22 patients (8-17 years) referred to a motility center (J Pediatr 2013; 162: 1181-7). The wireless motility capsule, also marketed as the SmartPill, has received FDA approval for use in the diagnosis of gastroparesis and constipation. It measures intraluminal pressure, temperature, pH, and allows calculation of transit times in different segments of the GI tract.
Methods:
All patients underwent antroduodenal manometry, gastric empyting study (GES), and wireless motility capsule study. The GES was performed with a 2-hour protocol. The patient was given a standardized meal of 2 eggs, toast, and jelly with Tc-99m labeled eggs. A GES was abnormal if >50% of labelled material was in the stomach at 2 hours. Similarly, the wireless motility capsule was ingested immediately prior to a similar standardized meal; this test was performed on a consecutive day with ADM testing.
Results:
- In the paper, Table II & III lists the values for each test and includes which data was missing.
- Based on ADM testing: 8 patients had rumination, 10 had normal motility, and 3 had abnormalities (1 with antral hypomotility, 1 with neuropathic dysmotility, 1 with hyperactivity/rumination).
- Based on wireless capsule, 10 patients had severe gastroparesis. Of these 10 patients, the ADM was normal in 4 and abnormal in 6.
The authors point out that the wireless motility capsule had excellent sensitivity but only moderate correlation between scintigraphic GES as well as ADM studies. One possible reason for increased identification of gastric emptying disorders for the capsule include the use of 2-hour rather than 4-hour GES. In addition, in symptomatic patients, those with normal GES and normal ADM may still have contractility abnormalities that can be identified with capsule test.
One limitation of the study was the fact that migrating motor complexes (MMCs) was detected in all patients by ADM (as well as by capsule). As such, there was no opportunity to identify potential false-positive in patients without MMCs. Similarly, healthy children were not studied and this limits the findings to a highly selected cohort of children referred for motility evaluation.
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gutsandgrowth 