Objective: Duplex scanning may be used to detect high-grade stenoses in the mesenteric vessels in patients with suspect Chronic Mesenterial Ischemia (CMI). The aim of the study was to evaluate reserve and collateral vascular function in relation to bowel symptoms in patients with CMI.
Methods: Fourteen consecutive patients, referred to the vascular laboratory with suspicion of CMI, 7 men
(average 79 years), and 7 women (average 66 years), were investigated by Duplex ultrasound (DUS) of the visceral arteries. All patients were examined both fasting and 30 min after a standard meal. A reference group of 10 patients with diffuse bowel symptoms (5 men and 5 women, (average 75 years) were investigated by the same DUS protocol, all showing normal mesenteric arteries. Possible collateral reserve capacity was defined as a marked increase of flow velocities (>20%) in vessels with lesions and/or in non-affected vessels.
Results: All patients had a significant stenosis (>70%) in one or several visceral arteries at the baseline DUS investigation. Six patients had abdominal pain after the test meal, whilst 8 patients experienced no pain. In patients without postprandial pain a possible collateral reserve capacity was detected. In this group superior mesenteric artery (SMA) peak systolic velocity (PSV) increased significantly (baseline PSV 2.6 ± 1.3 m/s vs. postprandial PSV 4.1 ± 1.6 m/s, P < 0.05) whereas patients with postprandial pain showed no signs of collateral reserve capacity in any vessel except one patient who showed possible collateral reserve in one vessel. In the reference group a significant increase of PSV was seen in SMA only, (1.7 ± 0.6, vs. 2.5 ± 0.9, P < 0.05).
Conclusion: Postprandial duplex adds information about the functional flow limitation of the stenosis and possible collateral reserve flow capacity. Further studies have to be performed to establish criteria for selection of patients appropriate for intervention.