J. R. Guitart3, V. Pamulapati1, S. Resnick1,2, K. J. Ho4 1Feinberg School Of Medicine – Northwestern University,Department Of Surgery,Chicago, IL, USA 2Feinberg School Of Medicine – Northwestern University,Department Of Radiology,Chicago, IL, USA 3Feinberg School Of Medicine – Northwestern University,Chicago, IL, USA 4Feinberg School Of Medicine – Northwestern University,Department Of Surgery, Division Of Vascular Surgery,Chicago, IL, USA
Introduction:
Superior mesenteric artery (SMA) stenting is routine treatment for mesenteric arterial occlusive disease, but is often complicated by in-stent restenosis (ISR). Duplex ultrasound (DUS) velocity criteria have been established for predicting significant stenosis (peak systolic velocity > 275 cm/s) in the native SMA. However, these criteria may overestimate SMA ISR and potentially result in unnecessary reinterventions. This study aims to define DUS criteria for the prediction of SMA ISR using paired DUS and angiographic data.
Methods:
We performed a retrospective single-center review of patients who underwent SMA stenting from 2016 to 2020. Postoperative CT angiograms (CTA) or traditional angiograms (TA) performed within 3 months of DUS were selected for inclusion. Maximum peak systolic velocity (PSV) and end diastolic velocity (EDV) in the stented SMA were recorded. For each TA and CTA, 2 independent reviewers measured the diameter of maximum stenosis and the reference SMA diameter with electronic calipers to calculate percentage stenosis. For CTA, measurements were obtained in axial, sagittal, and coronal planes. The plane demonstrating maximum stenosis was used for analysis. For TA, measurements were obtained in the lateral view.
Results:
There were 48 paired DUS and angiographic studies (22 TA and 26 CTA). PSV and EDV were both higher in patients with >70% angiographic ISR (PSV: 547 cm/s vs. 331 cm/s, p < 0.001; EDV: 155 cm/s vs. 73.3 cm/s, p < 0.001) than those without ISR. Receiver operator characteristic (ROC) analysis demonstrated that maximum PSV on DUS was a better predictor of > 70% ISR than EDV (p = 0.047). Optimal DUS criteria for predicting 70% ISR were a maximum PSV of ≥ 450 cm/s (sensitivity=100%, specificity=97.2%, PPV=92.3%, NPV=100%) or EDV of ≥ 80 cm/s (sensitivity=91.7%, specificity=74.3%, PPV=60% NPV=97%). A criterion of combined PSV ≥ 450 cm/s and EDV ≥ 80 cm/sec also accurately defined high grade ISR (sensitivity=100%, specificity=89%, PPV=75%, NPV=100%).
Conclusion:
Our study is the first to use of multiplanar CTA in addition to TA to validate DUS criteria for SMA ISR. Results are concordant with the existing literature suggesting that DUS velocity criteria (PSV and EDV) for native SMA stenosis overestimate ISR. We found that the optimal PSV criteria of ≥ 450 cm/s demonstrated high sensitivity and specificity for the diagnosis of >70% SMA ISR and combined criteria (PSV ≥ 450, EDV ≥ 80) showed similar accuracy. Ongoing studies seek to identify stent and imaging characteristics associated with false positive DUS findings which are associated with unnecessary confirmatory CTA or TA.
