Natural history of superior mesenteric artery in-stent restenosis

Objective Superior mesenteric artery (SMA) stenting is the preferred approach for patients with symptomatic SMA-associated chronic mesenteric ischemia (CMI). The durability of this modality is impacted by in-stent restenosis (ISR). Duplex ultrasound (DUS) and computed tomographic angiography (CTA)-measured ISR may be weakly correlated and not uniformly associated with recurrence of presenting symptoms. This study aims to analyze the association between the degree of ISR for patients with CMI and to develop a predictive model for symptom recurrence. Methods Single center, retrospective study included all patients with CMI with SMA stents from the period of 2003 to 2020. Follow-up period analysis included patients' symptoms recurrence, DUS, CTA, and angiography. A receiver operating characteristic (ROC) analysis was used to evaluate whether peak systolic velocity (PSV) was predictive of symptom recurrence. A subgroup analysis of patients (asymptomatic and symptomatic) with SMA ISR was identified; restenosis defined by DUS with peak systolic velocity (PSV) ≥350. Results The study included 186 patients with the ROC analysis obtained from 503 postoperative visits. PSV was not a predictor of symptoms return with area under the curve (AUC) = 0.49 (95% confidence interval [CI], 0.40-0.57). Agreement analysis between imaging modalities showed higher agreement between CTA and angiogram (AUC, 0.769; 95% CI, 0.688-0.849) vs CTA and DUS (AUC, 0.650; 95% CI, 0.589-0.711). The subgroup analysis of patients with ISR included 99 patients (asymptomatic n = 67; symptomatic n = 32). There was no statistical difference between median time (months) to ISR between both groups: 4.5 (asymptomatic group) and 7.6 (symptomatic group). The use of preoperative antiplatelet (86% vs 65%; P = .015) and P2Y12 receptor blockers (36% vs 13%; P = .016) was more prevalent in the asymptomatic group. There was no difference between the type or number of stents placed, stent diameter, or concomitant celiac artery intervention between both groups. Conclusions The natural history of SMA and multimodality defined ISR in CMI has not previously been described. Elevated PSV was a poor predictor of symptoms recurrence. Both asymptomatic and symptomatic patients with ISR did not differ in type of stent placed, time to ISR, or involvement of celiac artery. Antiplatelet use pre- and postoperatively appears protective against symptoms recurrence. Our findings underscore the need for long-term surveillance integrating clinical evaluation and multimodality imaging when indicated.