Application of duplex ultrasound imaging in determining in-stent stenosis during surveillance after mesenteric artery...

Currently, there are no well-established duplex ultrasound (DUS) criteria for the evaluation of the mesenteric arteries after stenting for occlusive disease. Previous studies suggested DUS velocity criteria in the native superior mesenteric artery (SMA) overestimate stenosis in stented arteries, but most studies have not evaluated DUS imaging after SMA stenting longitudinally. This study was undertaken to determine the accuracy of DUS after mesenteric artery revascularization and, in particular, to evaluate the utility of DUS imaging for the detection of in-stent stenosis (ISS) of the SMA.

A retrospective record review was performed for all patients who underwent SMA stenting for chronic mesenteric ischemia at a single institution from January 2004 to May 2011.

Mesenteric artery occlusive disease resulted in 24 patients undergoing mesenteric stenting of the SMA alone (n = 20) or the SMA and celiac artery simultaneously (n = 3). The mean ± standard deviation peak systolic velocity (PSV) in 13 prestent DUS images of the SMA was 464 ± 130 cm/s. Prestenting angiography revealed an average SMA stenosis of 79% ± 14%. After stenting, completion angiography in each case revealed <20% residual stenosis. No significant correlation was identified between SMA PSV and angiographic stenosis before and after stenting (P > .05). Follow-up SMA DUS imaging showed an average PSV of 335 ± 138 cm/s at 0.9 ± 1.5 months, 360 ± 143 cm/s at 4.8 ±2.6 months, and 389 ± 95 cm/s at 14.4 ± 5.1 months. A significant difference existed between the prestent and the first poststent mean SMA PSV (P < .05), but no significant difference existed between each poststenting interval. Eight reinterventions for SMA ISS were performed, with a mean elevated in-stent SMA PSV of 505 ± 74 vs 341 ± 145 cm/s in patients who did not undergo reintervention. Angiography before the eight reinterventions demonstrated an average SMA ISS of 53% ± 25%. In-stent SMA PSV decreased from 505 ± 74 to 398 ± 108 cm/s after the reintervention (P < .05).

Consistent with other reports, our data demonstrate the PSV in successfully stented SMAs remains higher than the PSV threshold of 275 cm/s used for the diagnosis of high-grade native SMA stenosis. In addition, in-stent SMA PSVs did not significantly change over DUS surveillance for patients who did not undergo reintervention. Thus, obtaining a baseline DUS early after mesenteric stenting should be considered to compare future surveillance DUS. An increase above this baseline or an in-stent SMA PSV approaching 500 cm/s should be considered suspicious for ISS, but larger prospective studies will be required to validate these preliminary findings.