Correlation Study Between Superior Mesenteric Artery Angle And Spontaneous Isolated Dissection Of The Superior Mesenteric Artery

Background and purposeThe spontaneous isolated dissection of the superior mesenteric artery(SIDSMA)is a rare vascular disease,which was reported for the first time by Bauersfeld in 1947,with the development of advanced imaging technology,in particular,with the universal application of multi-slice spiral computed tomography angiography(MSCTA),there are more and more SIDSMA have been diagnosed,including some asymptomatic SIDSMA.The etiology and underlying mechanism of SIDSMA is still not well studied,in the past,most of the literature reported more emphasis on the diagnosis and treatment of the disease,however,the etiology and the pathogenesis is rarely discussed.It is well accepted by researchers that the change of hemodynamics play an important role in the formation of aortic dissection,based on the view,we attempted to analyze the relationship between the hemodynamics changes and the SIDSMA,while the main factor affecting the blood flow in the superior mesenteric artery is the angle between the abdominal aorta(AA)and the superior mesenteric artery(SMA),Therefore,it is necessary to explore the relationship between superior mesenteric artery angle and SIDSMA.Materials and Methods35 patients with SIDSMA were retrospectively analyzed to investigate the clinical features in Endovascular department of the First Affiliated Hospital of Zhengzhou University from May 2014 to Feb.2017.Including 33 male and 2 female,aged 39-84 years,mean 51 years,all of them were confirmed by 64 rows of MSCTA of the whole aorta,and the angle of SMA were measured,then 35 normal adult SMA angles were collected who do not have any vascular disease,analyzing the difference of SMA angle between SIDSMA patients and normal adult;The distance from the entry site of SIDSMA to the origin of the SMA were measured,comparing the relationship between the distance and the SMA angle,and the results were analyzed.ResultsThe mean SMA angle of SIDSMA is larger than than of the normal adult(68.2±12.6° vs 55.8±17.8°;P<0.05),the difference is statistically significant,t=3.387,95%CI(5.129,19.850);the OR of the SMA angle with the incidence rate of SIDSMA is 1.054,95%CI(1.018,1.091).When the SMA angle between 50 ° ~ 80 °,the incidence rate of SIDSMA is up to 80%,of which the group between 60 ° ~ 70 ° include the most patients in all angles groups,accounting for 31.4%.Between 60 ° ~ 70 °,the entry site of SIDSMA is concentrated between 20-30 mm from the origin of the SMA,which region is transition zone of the SMA located.ConclusionsThe SMA angle and the incidence of SIDSMA have a certain relevance,when the SMA angle at 60 ° ~ 70 °,the incidence of SIDSMA may be higher.The incidence of SIDSMA may be affected by the combined effect of the SMA angle and the special anatomical structure of the SMA transition zone.