MESENTERIC AND CELIAC DUPLEX SCANNING - A VALIDATION-STUDY

Purpose: To validate the accuracy of previously established duplex ult rasound criteria for greater than or equal to 50% superior mesenteric artery (SMA) and celiac artery (CA) stenosis by comparison with arteri ography. Methods: Duplex criteria established retrospectively in our l aboratory in 1991 identified an end-diastolic velocity (EDV) greater t han or equal to 45 cm/sec, or no flow signal, as highly sensitive (100 %) and specific (92%) indicators for SMA stenosis greater than or equa l to 50% or occlusion. EDV was more accurate (95%) than peak systolic velocity (PSV), which had a maximal accuracy of 86% at a PSV greater t han or equal to 300 cm/sec, with low sensitivity (62%), but high speci ficity (100%). For CA, accurate velocity thresholds were not identifie d, but we subsequently noted that retrograde common hepatic artery now direction from SMA collateral was highly predictive of severe CA sten osis or occlusion. Since publication of those findings, 243 mesenteric duplex scans were performed for clinical evaluation of suspected chro nic mesenteric ischemia. Angiographic confirmation was available for a subset of 46. SMA and CA diameters were measured on lateral aortogram s by observers blinded to the duplex results, and the original duplex diagnostic criteria were tested for accuracy. In addition, receiver op erator characteristic curve analysis was performed on the velocity dat a to identify the most accurate velocity thresholds in the new data. R esults: Duplex was technically adequate in 98% of SMA, 96% of CA, and 89% of hepatic arteries, and arteriograms were adequate in 100% of SMA . and 98% of CA. For the SMA, EDV greater than or equal to 45 cm/sec a gain provided the best sensitivity (90%), specificity (91%), positive predictive value (90%), negative predictive value (91%), and overall a ccuracy (91%). As in the retrospective study, PSV greater than or equa l to 300 cm/sec provided low overall accuracy (81%), low sensitivity ( 60%), but high specificity (100%). Lowering the PSV threshold improved sensitivity but reduced accuracy. for CA, retrograde common hepatic a rtery now direction was 100% predictive of severe CA stenosis or occlu sion. Velocity data in CA provided accuracy not found in the original study. EDV greater than or equal to 55 cm/sec or no flow signal had be st overall accuracy (95%) with high sensitivity (93%) and specificity (100%). PSV greater than or equal to 200 cm/sec or no signal also had excellent accuracy (93%), sensitivity (93%), and specificity (94%). In addition, three of four anatomic anomalies were correctly identified by duplex. These included one right hepatic and one common hepatic art ery originating from the SMA, and one common celiacomesenteric trunk. Conclusion: This validation analysis confirms that duplex velocity cri teria are accurate in the identification of mesenteric occlusive disea se. Retrograde common hepatic artery now direction correctly predicts severe CA stenosis or occlusion. Duplex ultrasound may also identify m esenteric anatomic variants that can influence study interpretation.