Treatment of symptomatic isolated dissection of superior mesenteric artery

To present the short- to midterm outcomes after management of 14 patients with symptomatic isolated dissection of superior mesenteric artery (SIDSMA) and propose a preliminary treatment algorithm.

SIDSMA is a rare but potentially fatal entity. However, most of these reports were isolated case reports, and a consensus treatment protocol remains lacking so far. It would be meaningful to propose a reasonable treatment algorithm for it.

Patients with SIDSMA who were treated in our center between July 2007 and June 2011 were retrospectively collected and analyzed. Based upon the abdominal pain and signs, the clinical manifestations have been retrospectively classified into grade I (peritonitis absent) and grade II (peritonitis present). Medical treatment mainly included anticoagulation, antiplatelet, and bowel rest. Endovascular stent placement and surgical fenestration with exploratory laparotomy have been selected according to the grade classification. Computed tomographic angiography, magnetic resonance angiography, or duplex scans have been used for diagnosis and follow-up.

Fourteen consecutive patients with SIDSMA were collected; among them, 13 cases belonged to grade I and one to grade II. The mean duration from the onset to the admission was 12 ± 12 days (range, 0.5-45 days). The mean distance from the primary tear to the ostium of superior mesenteric artery (SMA) was 26 ± 4 mm (range, 15-32 mm). Medical treatment was given for 13 patients of grade I for the first 3 to 5 days after admission, and the abdominal pain remarkably or completely resolved in four patients who received continued medical treatment, whereas the other unresolved nine patients were converted to endovascular stent placement that succeeded in four and failed in five patients. Since these five cases were free from peritoneal signs, medical treatment was given again instead of an immediate surgical intervention, and ultimately achieved complete alleviation of abdominal pain within the following 1 week. The mean duration from the start of medical treatment to the alleviation of symptoms, including the continued medical treatment after the failed endovascular stent placement, was 8 ± 3 days (range, 4-12 days). The grade II patient underwent a successful emergency surgical SMA fenestration without bowel resection. Follow-up was accomplished in all 14 cases, ranging from 2 to 48 months (mean, 30 ± 15 months). No intestinal necrosis, morbidity, or mortality developed during hospitalization. During the follow-up, all patients were free from aneurysmal formation of SMA or chronic intestinal ischemia, and all stents remained patent.

For grade I SIDSMA, most cases might be successfully treated with medical therapy, and the endovascular stent placement appears to be an acceptable alternative if medical treatment fails. For grade II SIDSMA, the endovascular stenting combined with laparoscopic exploration and/or open surgery could be a reasonable option.