Role of Imaging Classification in Guiding Treatment Strategies for Spontaneous Isolated Superior Mesenteric Artery Dissection: A Comparative Study of Conservative and Endovascular Approaches

INTRODUCTION: The condition of spontaneous isolated superior mesenteric artery dissection (SISMAD), although rare, is becoming more widely recognized and can cause considerable gastrointestinal morbidity. Our study compared the outcomes between patients who successfully responded to initial conservative management and those who required subsequent endovascular intervention after initial conservative treatment failure for SISMAD, specifically comparing bare-metal stent (BMS) treatment to bare-metal stent-assisted coiling (BMSAC) treatment. METHODS: From January 2017 to December 2023, a retrospective study was performed involving 136 patients diagnosed with SISMAD at our hospital. Our center prioritizes initial conservative management for SISMAD patients. Endovascular intervention is pursued only when conservative treatment fails, indicated by persistent abdominal pain or progressive SMA dissection. Patients were divided into 3 groups based on treatment: conservative, BMS, and BMSAC. Treatments were tailored based on symptoms and computed tomography angiography (CTA) findings, employing the Sakamoto classification system. Clinical and imaging data were analyzed to assess treatment outcomes, and the primary endpoint is the rate of complete remodeling. RESULTS: The study encompassed 136 patients, including 121 men. Of these, 49.3% (n=67) received conservative treatment, 33.1% (n=45) underwent BMS, and 17.6% (n=24) were treated with BMSAC. In total, 75.0% of patients in the conservative treatment group achieved symptom relief, and all patients (100%) who underwent BMS or BMSAC saw symptom improvement. The rate of cumulative complete vascular remodeling was higher in the BMSAC group at 95.8%, compared to 73.7% in the bare stent treatment group (p=0.039). The time for complete remodeling differed significantly across the 3 groups (p<0.001). Based on the Sakamoto's classification type, the conservative vs intervention rates were type I, 11 (40.7%) vs 16 (59.3%); type II, 3 (20%) vs 12 (80%); type III, 27 (52.9%) vs 24 (47.1%); and type IV, 23 (82.1%) vs 5 (17.9%), respectively, and there was a statistically significant difference (p=0.001). CONCLUSION: For SISMAD, initial conservative treatment proves both safe and effective, particularly for symptomatic type IV patients. When required, endovascular interventions are tailored according to detailed imaging results. Both BMS and BMSAC initially alleviate symptoms effectively, but BMSAC is superior in achieving completely vascular remodeling, particularly notable in type I and chronic dissections.Clinical ImpactThis study provides important insights into the treatment of Spontaneous Isolated Superior Mesenteric Artery Dissection (SISMAD), highlighting the efficacy of both conservative and endovascular approaches. We find that initial conservative treatment is safe and effective, particularly for symptomatic Type IV patients, aligning with European guidelines that recommend conservative management as a first-line treatment. However, for cases requiring intervention, endovascular treatments, specifically bare metal stent-assisted coiling (BMSAC), show superior outcomes in achieving complete vascular remodeling compared to bare metal stent (BMS). This study supports the tailored use of endovascular procedures based on detailed imaging, thus enhancing treatment protocols and potentially improving patient outcomes in clinical practice.