Natural Course and Treatment of Symptomatic Spontaneous Isolated Superior Mesenteric Artery Dissection with Total True Lumen Occlusion

Abstract

Objective We retrospectively investigated the association between the imaging features of spontaneous isolated superior mesenteric artery dissection (SISMAD) accompanied by total true lumen occlusion and the clinical symptoms to identify the patients at high risk and establish personalized therapeutic options. Methods Among 261 patients with SISMAD, we selected 37 with Yun’s type III dissection; 35 patients underwent successful conservative management and 2 patients underwent exploratory laparotomy. After discharge, all patients were periodically followed up on an outpatient basis. We recorded patients’ general condition, symptoms, time until symptom relief, imaging findings and follow-up results. Results All patients experienced acute abdominal pain prior to admission, with an onset time of 29.95 ± 24.66 hours. The mean time until relief of abdominal pain in patients who received conservative treatment was 42.17 ± 38.09 hours. Correlation analysis revealed no correlation between the length of dissection or of the occluded segment and abdominal pain intensity. Pain scores were lower and time until pain relief was shorter in patients with a definite arc of Riolan (AOR) on admission than in those without an AOR. No collateral circulation was observed in the two patients who underwent exploratory laparotomy, and distal intestinal perfusion was poor in these cases. Complete and partial remodeling of the superior mesenteric artery (SMA) was observed in 6 and 16 patients, respectively at the 12-month follow-up. Although the SMA remained occluded in 12 patients, abundant collateral circulation was detected. Three patients were lost to follow-up. Conclusion This study highlights that conservative treatment should be attempted as first-line therapy in most patients with Yun’s type III SISMAD. Complete AOR can contribute to remission of clinical symptoms during the acute stage. Poor distal blood flow of occluded vessels may serve as an important indicator for identification of patients at high risk of ischemic intestinal necrosis.

A Case of Isolated Superior Mesenteric Artery Dissection Resulting in Recurrent Necrosis of the Small Intestine

“…Furthermore, several authors have reported that even in cases where the true lumen is occluded, as in Yun's type III, the prognosis is often good with conservative treatment and type IIb recovers spontaneously because of the absorption of false lumen thrombus, and conservative treatment should be considered. 21,23,[26][27][28] In our case, the true lumen of the SMA dissection site was narrowed but not completely occluded, and the contrast effect of the SMA main trunk distal to the dissection site was maintained. If our cases had been type III, we would have performed revascularization during the initial surgery.…”

Factors associated with false lumen changes in patients with superior mesenteric artery dissection

“…32 In type III SMAD, occlusion of the SMA restricts the collateral blood supply, which puts the patient at high risk of intestinal necrosis; thus, early intervention is generally recommended. 33 Based on our results, patients with type IIa SMAD often have the most obvious FLCs within the 1-month follow up after diagnosis, so it is necessary to strictly follow up and manage all patients during this period. For patients with rapid reduction of false lumen within the 1-month follow up, we could appropriately prolong the follow-up interval and reduce unnecessary CTA examination.…”