Morphological Study Of Spontaneous Isolated Dissection Of The Superior Mesenteric Artery And Treatment Strategies Based On New Classification

Backgroundspontaneous isolated dissection of the superior mesenteric artery,SIDSMA is a rare acute abdomen.Severe cases of SIDSMA can cause intestinal necrosis and rupture of mesenteric arteries that endanger life.The etiology of the disease is unclear and there is no consensus on classification and treatment.The occurrence of SIDSMA and B-type aortic dissection is somewhat similar in mechanics,and the breach is often found in the vascular transition.The angle between the superior mesenteric artery and the aorta.Positive correlation with the incidence of SIDSMA,the larger the angle,the more likely to occur sandwich.The role of anatomy and mechanics in SIDSMA is also suggested.This study attempts to investigate the pathogenesis of SIDSMA in terms of hemodynamic changes.In this study,we used the new morphological subtypes and subtypes proposed by our center to emphasize the patency of the superior mesenteric arteries in patients with SIDSMA.The concept of residual diameter.The clinical features and imaging data of patients with SIDSMA were mainly CTA images(new classification,location of dissection lesions,involving length and diameter of true and false lumens,angle between superior mesenteric artery and abdominal aorta),mortality,and follow-up results,According to the new SIDSMA classification to develop a treatment plan.In this study,we retrospectively analyzed 178 patients with SIDSMA who were consecutively treated in this center,analyzed their clinical data,and according to their CTA imaging findings,classified them according to new morphological classifications,formulated treatment plans,and follow-up results after hospital discharge.The treatment of superior mesenteric artery dissection was explored,combining domestic and international literature data,and the efficacy of SIDSMA based on new classification treatment strategy was explored.It is hoped that the results of this study can provide reference for the development of treatment strategies for this disease.purposes1.Taking the angle between the superior mesenteric artery and the abdominal aorta and the position of the rupture as the research object,try to discuss the pathogenesis of SIDSMA from the perspective of hemodynamic changes.Patients were typed with the new SIDSMA morphological typing.2.The use of new SIDSMA morphology to guide the application of SIDSMA and clinical resultsResearch methods1 patient informationThis retrospective study selected the clinical data of 178 consecutive patients who had been diagnosed as spontaneously isolated superior mesenteric artery dissection in the center of our hospital from January 2013 to December 2016.All patients received conservative treatment,endovascular treatment or Open surgical treatment.2 Imaging diagnosis and measurementIt was diagnosed by abdominal aorta computed tomography(Computed tomography angiography,CTA),and CTA was used to evaluate the angle between the superior mesenteric artery and abdominal aorta,the rupture of SIDSMA,and the residual diameter of the superior mesenteric artery.3 T reatmentConservative treatment:including fasting,parenteral nutrition support,gastrointestinal decompression,low molecular weight heparin anticoagulation,control of blood pressure.Open surgery:Including necrotic small intestine resection and intestinal anastomosis,superior mesenteric artery thrombectomy and intimal trimming or intimal reconstruction,and abdominal aorta superior mesenteric artery autologous saphenous vein bypass.Intraluminal reconstructive surgery of superior mesenteric artery:including stent placement,intraluminal coil embolization of aneurysm in aneurysm.4 Follow-upFollow-up patients' clinical conditions at 1 month,6 months,12 months,and every year,and abdominal aorta CTA examination5 Statistical analysisIn this study,spss19.0 was used for statistical analysis.Chi-square test was used to compare the count data between groups.The comparison of measurement data between the three groups was first tested for homogeneity of normality and variance,consistent with normality and homogeneity of variance using single factor.Analysis of variance method,the results as mean ± standard deviation,does not meet the Kruskal-Wallis H test,the results are expressed as the median(minimum,maximum).p<0.05 indicates a statistical difference.Result1 General conditions and preoperative dataA total of 178 patients with SIDSMA were included.Including 160 males and 18 females;aged 33-80 years old,average 52.8 years old.There were 50 patients in the conservative treatment group,9 in the open surgery group,and 119 in the endovascular treatment group.The average age of the conservative treatment group(52.72±18.23),the average age of the endovascular treatment group(53.62±14.26),and the mean age of the open surgery group(54.22±16.91),there was no significant difference between the three groups.No significant difference between men and women in the three groupsIn the endovascular treatment group,the rate of dissection in one area was the highest,and p<0.05 was statistically significant between the three groups.The rate of dissection in the endovascular treatment group was also highest in the second area,and p<0.05 was statistically significant between the three groups.The residual diameter of the true cavity in the conservative treatment group(57.4%vs 0 vs 25.7%)was greater than the other two groups,and p<0.05 was statistically significant between the three groups.The residual diameter of the true cavity in the conservative treatment group was more than 30%(30vs 0 vs 21%),which was also greater than the other two groups.p<0.05 was statistically significant.Morphological typing,type ? in the conservative treatment group,the most patients,p<0.05 was statistically significant;type ? intraluminal treatment group was the most,p<0.05 was statistically significant;type ? intraluminal treatment group was the most.P<0.05 was statistically significant;?-type endovascular treatment group was the most.p<0.05 was statistically significant.There was no statistical difference between the two groups in type ?.The angle between the abdominal aorta and the superior mesenteric artery,that is,the angle of SAA was in the range of 70°-80°,the SIDSMA lesion group was compared with the control group.p<0.05 was statistically significant.There was a significant difference in the number of conservative treatment failures among SIDSMA patients who were conservatively treated with subtype a in subgroup I and other subtypes of SIDSMA compared with subtypes b and c.p<0.05 was statistically significant.During follow-up,CTA of the superior mesenteric artery was examined.Changes in CTA in the three groups were found:improvement,no change,and significant difference in progression.p<0.05 was statistically significantDuring the follow-up,there were significant differences between the three groups of recurrences of abdominal pain symptoms.p<0.05 was statistically significant.During the follow-up,there were significant differences between the three groups of treatment and the death and total death associated with the disease.p<0.05 was statistically significant.2 Surgery and 30 days after surgeryIn this study,119 patients received endovascular therapy with a technical success rate of 94.9%.6 patients were treated conservatively because of failure in endovascular treatment.Within 30 days after surgery,one patient died of multiple organ failure due to intestinal necrosis within one week after surgery.Hematoma in 11 cases.Nine patients in the open surgery group and one patient in 30 days died of septic shock due to intestinal anastomotic leakage.The remaining 50 patients received conservative treatment,and 8 patients were treated with conservative treatment and failed intraluminal treatment.The duration of hospitalization was the longest in the open surgery group,followed by the endovascular treatment group,and the shortest in the conservative treatment group(19.4 vs 10.9 vs 9.1 days).There was a statistical difference between the three groups(p<0.05).3 Follow-up resultsThe average follow-up was 534.45 days(48 to 973 days).After 30 days,there was 1 case of related surgery and 2 cases of death.There was no significant difference between the three groups4 General Information for the Endovascular Treatment Group StudyA total of 119 patients were 109 males and 10 females.Among them,27 patients with aneurysm embolism with dissection aneurysm were present..5 Endovascular stent placement surgery and 30 days results119 patients received superior stenting of superior mesenteric artery(27 patients underwent intraluminal coil embolization at the same time),of which 6 patients failed and the technical success rate was 94.9%.A total of 11 complications were found within 30 days after operation.One patient developed multiple organ failure due to intestinal necrosis and intestinal perforation.Except for the death patients who underwent bowel resection,none of them received re-related intraluminal or open surgery within 30 days.Conclusion1.The incidence of SIDSMA is related to the angle between the SMA and the abdominal aorta.The incidence of SIDSMA is highest when the angle is between 600 and 70°.The position of the rupture is 2-3cm higher than the distance of the superior mesenteric artery.The predilection site of SIDSMA is at the transition of SMA from a relatively fixed to a free zone.2.The new classification of SIDSMA has a good guiding significance for treatment strategies.For type ? and ?a,type ?a patients with SIDSMA who have smooth patency,conservative treatment is preferred,but close observation of symptoms and regular review are needed.3.Endovascular treatment of SIDSMA has a good technical success rate and safety.It is recommended that patients with SIDSMA with severe stenosis(?b type,?b type,IVb type)and true cavity occlusion(?c type,?c type,IVc type)in true cavity No peritoneal symptoms are preferred.4.For type V(dissection aneurysm)patients,in order to prevent rupture of the aneurysm,it is recommended that endovascular treatment be performed as soon as possible,and stent implantation plus false cavity coil embolization.5.Open surgery is indicated for patients with SIDSMA who have severe peritonitis symptoms and rupture of dissecting aneurysms.6.It is recommended that a comprehensive treatment strategy for patients with SIDSMA be developed based on clinical symptoms and morphological classification,and that personalized treatment be applied to the specific conditions of the patient.