Duplex velocity criteria for native celiac/superior mesenteric artery stenosis vs in-stent stenosis.

BACKGROUND: Duplex velocity criteria (DVC) to identify in-stent celiac artery (CA) and superior mesenteric artery (SMA) stenosis is not well defined. Only one study has been published which concluded that DVC for native SMA stenosis overestimated stenosis in stented SMAs. The purpose of this study was to analyze DVC in detecting CA/SMA in-stent stenosis (ISS).

METHODS: Forty-three patients with 62 stents (32 SMAs and 30 CAs), who had concurrent postoperative duplex ultrasound scan and angiograms for significant ISS by DVC were analyzed. A receiver operator curve (ROC) analysis was used to determine optimal DVC (peak systolic velocity [PSV], end-diastolic velocity [EDV], and CA or SMA/aortic systolic ratios) for detecting ≥50% and ≥70% ISS. These were compared to duplex velocities obtained from 97 native CAs and 74 native SMAs with ≥50% stenosis done in the same study period.

RESULTS: The mean stented celiac PSV (cm/s), EDV, and systolic ratio for ≥50% ISS were 447, 136, and 7.1 vs 379, 104, and 5.2 for ≥50% native stenosis (P = .067, .106, and < .01). The mean stented SMA PSV, EDV, and ratio for ≥50% ISS were 410, 114, and 6.2 vs 405, 76, and 2.0 for ≥50% native stenosis (P = .885, .037, and < .0001). The PSV cutpoints for detecting ≥50% SMA ISS was 325 cm/s (sensitivity 89%, specificity 100%, and overall accuracy 91%) vs 295 cm/s for ≥50% native SMA and for ≥70% SMA ISS was 412 (sensitivity 100%, specificity 95%, and overall accuracy 97%) vs 400 for native stenosis. The PSV cutpoints for ≥50% CA ISS was 274 cm/s (sensitivity 96%, specificity 86%, and overall accuracy 93%) vs 240 cm/s for ≥50% native stenosis and for ≥70% CA ISS was 363 (sensitivity 88%, specificity 92%, and overall accuracy 90%) vs 320 cm/s for native stenosis (sensitivity 80, specificity 89%, and overall accuracy 85%). ROC analysis also showed that both PSVs and EDVs were equal predictors for SMA and CA ≥50% and ≥70% ISS. For ≥50% SMA ISS, the area under the curve (AUC) for PSV equals 0.91, EDV = 0.81, P = .341. For CA, PSV, AUC = 0.99, EDV = 0.88, P = .063.

CONCLUSIONS: There is a tendency toward higher velocities in stented CA/SMAs in comparison to native arteries. Caution must be exercised in using duplex velocity cutoffs for native CA/SMA stenosis for stented CA/SMA. Further prospective validation studies are needed.