This policy is consistent with the conclusions of a technical review by the American Gastroenterological Association (AGA) (Quigley et al, 2001).
Antroduodenal manometry is a relatively new technique for the evaluation of gastric and small intestinal motor function. Antroduodenal manometry is used to measure the contractile activity of the distal stomach and duodenum. Changes in intra-luminal pressure of the stomach and duodenum are measured through perfusion ports or solid-state transducers incorporated in a catheter that is positioned under fluoroscopic guidance. Results are recorded and may be analyzed either by direct visual inspection or using a computer. Recordings may last from 5 hours (stationary study) to 24 hours (ambulatory study).
Intra-luminal pressure changes are measured both in the fasting state and after meals. In the fasting state, the presence of the muscle contractions and their site of initiation, direction of propagation, frequency, and duration are assessed. After the meal, conversion to the fed state is identified, and the duration of the fed pattern is calculated. Post-prandial antral hypomotility is a common finding among those with unexplained nausea and vomiting and delayed gastric emptying, and manometry has also been reported as useful in identifying those with primary or diffuse motor disorders. However, the interpretation of antroduodenal manometric recordings requires substantial experience and recognition of the considerable range of normal variation. The specificity of many reportedly abnormal patterns has rarely been confirmed by correlation with histological studies.
A technical review from the AGA (Quigley et al, 2001) stated that, if tests of gastric function reveal delayed emptying or abnormal myoelectrical activity, antroduodenal manometry is of little added value. Antroduodenal manometry may be indicated when the gastric emptying or electrogastrography results are normal or equivocal and severe symptoms persist despite empiric therapeutic trials. Occasionally, findings consistent with chronic intestinal pseudo-obstruction may be revealed or features consistent with mechanical obstruction identified in patients in whom they had not been detected radiographically. A normal antroduodenal manometry result may be of value in patients with unexplained nausea and vomiting: by demonstration of normal motor function in the antrum and the duodenum, any lingering questions regarding dysmotility can be resolved and the diagnostic evaluation redirected elsewhere.
Steinbrueckner and associates (1996) reported that a motility pattern consisting of continuous simultaneous contractions at high frequency from the antrum down to the upper jejunum was associated with repeated vomiting.
Verhagen and colleagues (1999) evaluated the outcome of antroduodenal manometry studies and their effect on the clinical treatment of patients. Nausea and vomiting were the most predominant symptoms (37.4 %). In 49.5 % of the cases, the test was performed due to suspicion of a generalized motor disorder. A normal outcome was found in 37 studies. Non-specific motor abnormalities were reported in 72 % of the studies with an abnormal outcome. Pseudo-obstruction was diagnosed in 20 %. The manometric studies resulted in a new therapy in 12.6 %, a new diagnosis in 14.9 %, and referral to another specialist in 8 %. A positive clinical impact was found in 28.7 % of the patients. The authors concluded that antroduodenal manometry can be a helpful diagnostic technique in a specialized center.
These findings are in accord with those of Hyman et al (1990), who stated that antroduodenal manometry is a useful technique that elucidates the underlying gastrointestinal motility disorder present in the majority of children and adolescents with severe functional symptoms.
Glia and Lindberg (1998) studied the antroduodenal motor activity in 20 patients to ascertain whether patients with slow-transit constipation may have a generalized intestinal motor disorder. They found a significant proportion of patients with slow-transit constipation have manometric findings that indicate a generalized motor disorder of the gut. However, the clinical significance of these findings is unclear.
Byrne and Quigley (1997) concluded that in the evaluation of suspected foregut motor dysfunction, antroduodenal manometry may provide clinically useful information in selected patients; information which may not be available from standard diagnostic tests, including nuclear medicine gastric-emptying studies.
Stanghellini et al (2000) stated that only patients who remain undiagnosed after extensive traditional work-up and fail repeated courses with medical therapy should be referred for the manometric test.
Ghoshal et al (2008) stated that although antroduodenal manometry (ADM) is an important research tool, experience on its clinical utility is scanty. These researchers reported their experiences on this procedure. All ADM performed as a clinical service, using an 8-channel water perfusion system were retrospectively analyzed. Impact on clinical management was classified as: (i) new diagnosis made, (ii) change in management (e.g., new drug, decision regarding surgical treatment), (iii) further special investigation done, and (iv) referral to another specialty. Antroduodenal manometry was successful in 32/33 (97 %) patients (age of 30 years; range of 8 to 71); 6 patients were less than 12 years old. Clinical impression before ADM was: chronic intestinal pseudo-obstruction (CIPO) in 16 (50 %), suspected gastroparesis in 11 (34.3 %), dyspepsia in 5 (15.6 %). Consequent to ADM in patients with CIPO, a new diagnosis was made in 2 (intestinal neuronal dysplasia and celiac disease), new drugs were started in 5, surgery was performed in 3 and specific referral was sought in 3. Antroduodenal manometry confirmed gastroparesis in 9 of 11 patients. A new diagnosis was made in 3 patients, new drugs were started in 3, and 3 were referred. In 5 dyspeptic patients, ADM was normal and no therapy was suggested. Overall, 11 patients with CIPO and 4 with gastroparesis benefited after ADM. The authors concluded that ADM was found useful in CIPO and gastroparesis, helped in decision-making regarding surgery; however in non-specific indications its utility was limited.
Sha and colleagues (2009) evaluated gastric slow waves, antral and duodenal motility simultaneously, and ascertained the correlation among all these measures in patients with functional dyspepsia. A total of 31 patients with functional dyspepsia were assessed for severity of upper gastrointestinal symptoms with the electrogastrography (EGG) and ADM. The EGG and ADM were recorded for 3 to 4 hours in the fasting state and for 2 hours after a solid meal. Computerized spectral analysis methods were used to compute various EGG parameters. The EGG was abnormal in 71.0 % of patients. The abnormalities included normal slow waves lower than 70 % in the fasting state (51.6 % of patients) and in the fed state (48.4 % of patients), a decrease in dominant power in 28.9 % of patients. Antral motility was abnormal in 80.6 % of patients and duodenal motility was abnormal in 74.2 % of patients. For the EGG and antral motility, 19 of 31 patients had both abnormal EGG and abnormal antral motility; 2 of 31 patients had both normal EGG and normal antral motility. For the EGG and duodenal motility, these values were 16/31 and 2/31, respectively. By both EGG and ADM, abnormal gastric motor function was found in 93.5 % of patients. However, quantitative one-to-one correlation between any of the EGG parameters and the antroduodenal dysmotility was not noted. The patients showed high symptom scores especially to upper abdominal pain, nausea, and belch. No one-to-one correlation was noted between the symptom scores and any of the EGG or motility parameters. The authors concluded that more than two-thirds of patients with functional dyspepsia have abnormalities in the EGG and antral/duodenal motility. The sensitivity of these 2 different methods is essentially the same. Electrogastrography and ADM can complement each other in demonstrating gastric motor dysfunction in patients with functional dyspepsia.