Utility of Standing Maneuvers during Abdominal Duplex Ultrasound Examination to Diagnose Median Arcuate Ligament Compression

Abstract

Introduction Median arcuate ligament compression (MALC) may present with abdominal pain as the result of dynamic compression of the celiac artery and the superior mesenteric artery (SMA). An asymptomatic patient may also demonstrate dynamic stenosis consistent with MALC on duplex examination. Duplex examination with maneuvers may differentiate fixed stenosis attributable to atherosclerosis (ASO) from dynamic stenosis caused by MALC. In MALC, elevated velocities normalize during deep inspiration. Performance of the Doppler examination with the patient standing may lead to improved diagnosis of MALC. Methods We performed a database query for all abdominal duplex examinations performed from January 1, 2007 to December 31, 2007 in which a standing (or seated) Doppler examination was reported. Studies were performed with a curved 5–2 MHz transducer (Philips iU22, Bothell, WA) with the patient in the fasting state. A peak systolic velocity (PSV) of ≥ 250 cm/sec in the celiac artery and a PSV of ≥ 275 cm/sec in the SMA were consistent with 70–99% stenosis. Results Ten patients were identified. Mean age was 51.2 years. A total of 60% of patients were female. Four patients presented for evaluation of abdominal pain and/or weight loss; six patients for other indications. Nine patients had increased PSV in the celiac artery at rest. The abnormality resolved with maneuvers in seven out of nine patients, consistent with MALC. In two patients, celiac artery PSV normalized with inspiration while they were supine; four patients in whom celiac artery velocity did not normalize with inspiration while they were supine had normal PSV while standing; one patient had normal celiac artery velocity while seated (no supine inspiration maneuvers performed); two patients had persistent celiac artery stenosis, likely because of ASO, although one normalized partially with standing. One patient had elevated velocities in the hepatic and splenic arteries that normalized with standing. Two patients had evidence of MALC of the SMA demonstrated with standing maneuvers. Conclusion Among patients with elevated velocities in the celiac artery and the SMA, repeated Doppler examination with the patient standing may demonstrate normalized velocities, consistent with MALC. The value of incorporating standing views into the abdominal duplex protocol to avoid false positive diagnoses of ASO merits prospective evaluation.