Is EUS with Doppler Comparable to Transabdominal Ultrasound As a Screening Test for Chronic Mesenteric Ischemia (CMI)?

Abstract

Background: EUS has been proposed as a single test to evaluate persistent upper abdominal pain as it can diagnose virtually all of the common causes of upper abdominal pain. CMI, a potential cause of upper abdominal pain, has not been previously evaluated by EUS. As Doppler flow in the celiac artery (CA) and superior mesenteric artery (SMA) can be measured, we propose that EUS can be used to screen for CMI. Doppler transabdominal ultrasound (TUS) has been validated as a non-invasive imaging modality used to screen for CMI. A peak systolic velocity above 275 cm/s in the SMA and 200 cm/s in the CA predict >70% stenosis in the mesenteric vessels. Methods: Patients undergoing evaluation for chronic abdominal pain with suspicion of CMI who underwent either EUS or TUS were reviewed. Doppler measurements of the peak systolic velocity of the CA and SMA were recorded. In addition, any other diagnoses discovered during the EUS examination were recorded. If MRA was performed, the findings were compared with the values obtained during EUS or TUS. MRA was considered as the gold standard when available. A stenosis >70% was considered a positive test. Alternatively, if MRA was not available, a negative TUS and EUS was considered as a negative gold standard. Kappa statistics were used to compare the agreement between each diagnostic modality. Results: A total of 42 patients were included in the study (38 underwent EUS, 24 underwent TUS, 22 underwent MRA and 28 had a gold standard result available). Doppler measurements of the CA could be performed in all 38 patients (100%) and the SMA could be measured in 29 patients (76%). EUS and TUS had comparable accuracies evaluating the presence of abnormally elevated flow in the CA (85% vs. 88%) and SMA (96% vs. 95%). EUS and TUS had moderate concordance with MRA for the CA (kappa = 0.54, 0.54) and the SMA (kappa = 0.64, 0.63). When either the CA or SMA was positive, EUS predicted the presence of stenosis in the CA or SMA with a sensitivity of 80% as compared to TUS, which had a sensitivity of 67%. Of the 38 patients undergoing EUS, 19 examinations yielded additional diagnoses, which included chronic pancreatitis, pancreatic cyst, gastric and duodenal ulcer, choledocholithiasis and pancreatic cancer. Conclusions: CA and SMA Doppler flow measurements can be obtained during EUS examination. EUS measurements of the CA and SMA are as reliable as TUS in the detection of CMI. EUS has an advantage over TUS as it can yield alternative disorders that may be contributing to chronic upper abdominal pain. EUS with Doppler has the potential to be used as a single comprehensive test in the evaluation of persistent upper abdominal pain.