Objective: To investigate the efficacy of endovascular treatment in patients with recurring symptoms after initial successful conservative treatment for symptomatic isolated superior mesenteric artery dissection (ISMAD).
Methods: The clinical data of 8 patients who experienced recurring symptoms after initial successful conservative treatment for symptomatic ISMAD undergoing endovascular treatment between July 2015 to June 2017 in the Department of Vascular Surgery of the Affiliated Zhongshan Hospital of Fudan University were retrospectively analyzed. 
Results: All the 8 patients were male with an average age of 51.14 years. The clinical symptoms of the patients recurred after conservative treatment, and the CT scan findings were aggravated compared with the initial observation. Endovascular treatment was successfully performed in 5 patients with 11 stents implanted. Endovascular treatment was unsuccessful in 3 patients because the guide wire failed to enter the distal true lumen, of whom, 2 cases were continued with conservative treatment and 1 case was converted to open surgery. Clinical symptoms of the 5 patients with successful endovascular treatment were completely alleviated during the perioperative period. In the 3 failed patients, 2 cases presented with peritoneal stimulation, of whom, 1 case died due to severe peritonitis and multiple organ dysfunction and the clinical symptoms disappeared in another one who underwent open surgery after distal blood supply restoration; 1 case presented with persistent symptoms of superior mesenteric artery (SMA) ischemia and improved after medical treatment. The median follow-up time was 15 months. In the 5 patients with endovascular treatment, 2 cases had unsatisfactory remodeling of the SMA (partial thrombolization of the false lumen, stenosis in the distal true lumen and sparse display of the branches), 
1 case had partial remodeling and 2 cases had complete remodeling. The patient undergoing open surgery recovered well and the symptoms of chronic SMA ischemia disappeared. The symptoms of chronic SMA ischemia were still observed in the patients undergoing conservative treatment bur were markedly relieved compared with those at admission. 
Conclusion: Symptomatic ISMAD has certain risk of recurrence after initial successful conservative treatment. After recurrence, the disease may markedly worsen compared to the first onset, and the difficulty and failure rate of endovascular intervention are increased, which may cause severe adverse consequences.