Treatment Strategies For Superior Mesenteric Artery Dissection And Evaluation Of Renal Tissue Perfusion In Renal Artery Stenosis

Objectives:The treatment strategies of spontaneous isolated superior mesenteric artery dissection(SISMAD)are controversial.The study aimed to compare the long-term outcomes of conservative treatment and endovascular treatment in symptomatic patients.Methods:This study enrolled 65 SISMAD patients who were admitted to Peking Union Medical College Hospital between October 2009 and December 2020.Twenty-four had conservative treatment and 41 had endovascular treatment.The baseline characteristics,treatments,and follow-up results of both groups were analysed.Results:The rates of symptom relief were 95.8%(23/24)in the conservative group and 97.6%(40/41)in the endovascular group.There was one case of pseudoaneurysm formation in the left brachial artery.During the follow-up period(median time 27 months),the symptom recurrence rate in the conservative group was significantly higher than the endovascular group(30.4%vs 6.3%,p=0.026).Four patients in the conservative group and 1 patient in the endovascular group had additional endovascular treatment.Comparing with conservative group,patients in the endovascular group had longer symptom-free survival(p=0.019)and higher rate of superior mesenteric artery(SMA)remodeling(p<0.001).Conclusions:In the long term,SISMAD patients with endovascular treatment had lower symptom recurrence rate and higher SMA remodeling rate.The outcomes of both treatment need to be further confirmed by prospective,multicenter studies.Objectives:The clinical benefits of endovascular treatment in renal artery stenosis(RAS)remain controversial.This study observed the change of renal perfusion after endovascular revascularization in atherosclerotic RAS.Methods:In a prospective,single-center study,we assigned 30 patients with severe atherosclerotic RAS who underwent endovascular treatment between March 2016 and March 2021 in Peking Union Medical College Hospital.Flat-panel detector parenchymal blood volume imaging(FD-PBV)was used for renal perfusion analysis.Preoperative and postoperative results of renal perfusion,blood pressure,and renal function,were compared.Results:Before endovascular treatment,median kidney volume was 141.5(106.5-181.7)cm3,which increased to 148.6(129.6-186.3)cm3 after endovascular intervention(p<0.001).The median preoperative mean density of contrast medium was 304.0(224.8-380.9)Hounsfield unit(HU),and the median postoperative mean density of contrast medium was 339.9(283.8-396.8)HU(p=0.028).The ratio of postoperative and preoperative mean density of contrast medium differed a lot among the patients.The ratio of postoperative and preoperative mean density of contrast medium had negative correlation with the preoperative mean density of contrast medium(R=0.698,p<0.001).Depending on the preoperative perfusion levels,patients were divided into Subgroup A(mean density of contrast medium<279.4 HU,11 cases)and Subgroup B(mean density of contrast medium>=279.4 HU,19 cases).The mean density of contrast medium significantly increased after treatment in Subgroup A(p=0.003),but was similar in Subgroup B(p=0.780).Eleven(90.9%)patients in Subgroup A and 5(26.3%)in Subgroup B had more than 10%increase in the mean density of contrast medium.The median estimated glomerular filtration rate(eGFR)of Subgroup A had a trend of increase in the perioperative period(p=0.058).The mean blood pressure had significant decrease in both subgroups.On the other hand,4(36.4%)patients in Subgroup A and 2(10.5%)in Subgroup B used fewer antihypertensive drugs after endovascular revascularizationConclusions:RAS patients with relatively low preoperative renal perfusion levels had more perfusion increase after endovascular treatment,and benefited more in blood pressure control and renal function protection.Preoperative perfusion measurement might predict the effectiveness of endovascular treatment,and guide the treatment of RAS.Objectives:Currently,it is controversial that if endovascular treatment can improve prognosis of atherosclerotic renal artery stenosis(RAS).This preliminary study aimed to observe the change of renal perfusion after endovascular treatment in RAS patients using arterial spin labeling(ASL).Methods:We prospectively assigned 4 RAS patients who underwent endovascular treatment between October 2020 and March 2021 in Peking Union Medical College Hospital.All four patients had technical success.Preoperative and postoperative results of renal perfusion and kidney length-diameters were compared.Results:All 4 patients had successful endovascular treatment,and 2 of these patients had bilateral intervention.ASL could quantitatively measure the renal blood flow(RBF)of renal cortex.The mean preoperative length-diameter of the intervened kidneys was 9.3±1.1cm,which increased to 9.5±1.1cm after endovascular treatment.The mean preoperative RBF of the intervened kidneys was 154.5±60.0 mL/100g/min,and the mean postoperative RBF was 194.1±68.2 mL/100g/min,which increased significantly.Conclusions:ASL is an effective way of renal perfusion assessment in the endovascular treatment of RAS.ASL might help assess the effectiveness of endovascular intervention and evaluate the prognosis.