Conservative Versus Endovascular Treatment for Spontaneous Isolated Superior Mesenteric Artery Dissection: A Clinical and Imaging Follow-up Study

Purpose: Spontaneous isolated superior mesenteric artery dissection (SISMAD) is a rare vascular disease, the treatment strategies for which remain debated. This retrospective study aimed to compare the outcomes of conservative and endovascular treatments in patients with SISMAD. Materials and Methods: Fifty-eight patients with SISMAD confirmed by computed tomography angiography admitted to our hospital between November 2017 and May 2021 and received confirmed conservative (n=43) or endovascular (n=15) treatment. The patient demographics, imaging analysis, and follow-up results were analyzed and compared. Results: The cohort included 54 males and 4 females with a mean age of 52 years. Abdominal pain was the major complaint (49/58, 84.5%), followed by chest pain (2/58, 3.4%). The mean follow-up was 9.1 +/- 7.9 months. The 2 main Sakamoto types were type III (27/58, 46.6%) and type IV (16/58, 27.6%). Most patients in both groups had angle 1 (aortomesenteric angle) and angle 2 (superior mesenteric artery [SMA] course) of over 80 degrees. About 67.3% of patients had long length of dissection (>60 mm). The median distance between the SMA root and the dissection entry site was 1.5 cm, mostly (84.5% of the patients) in the curved segment of the SMA. Telephone follow-ups found that most patients survived pain-free, and none underwent intestinal resection. Only 4 patients, 2 in each group, had recurrent abdominal pain during follow-up and received stenting treatment to achieve complete vascular remodeling. Importantly, we found that the conservative and endovascular therapies achieved similar high remodeling rates (94% and 100%, respectively; p=0.335). The conservative group achieved satisfying vascular remodeling (partial, 35%; complete, 59%), making it as safe and effective a treatment as endovascular therapy. Conclusions: Initial conservative management is safe and effective in patients with SISMAD. A high technical success rate and favorable short-term outcomes were associated with endovascular procedures as secondary interventions. It would be helpful to conduct large-scale, prospective, randomized controlled trials with long-term follow-up for SISMAD. Clinical Impact 1. This research provided more detail clinical information, such as evaluation of abdominal pain and measurements of SMA angles, which is all relevant to treatment. 2. What's more, the most surprising results of follow-up part shown that conservative treatment could reached the remodeling rate as high as endovascular treatment, which was relatively low in other studies. It helps us share our treatment experience with clinicians. 3. In addition, we get limited knowledge about this rare disease, it's encouraging us to do more researches based on the results we had.