Morphological Study Of Aortic Dissection

Since Dake first reported using stent-graft to treat disease of thoracic aorta on N Engl J Med in 1999,EVR is becoming more and more popular method in treating aortic dissection.So far,the early results of endovascular repair of type B dissection is encouraging,however the mid-term and long-term results are still indefinite.In this study,we follow up all the Stanford type B dissection treated by endovascular repair(EVR) in our center.Our aim is to summarize the aortic dissection's morphological rules after EVR.Objective:Follow up type B dissection patients using CTA.Record the diameter of true lumen(TL),false lumen(FL) and aorta.Observe thrombosis in false lumen.Use the morphological data to prove the effect of EVR.Methods:1.Data measurement:91 type BAD were followed up,the CTA images was used to study the morphology of the aorta and the true and false lumens;to measure the different aortic TL and FL diameters;and to ascertain the degree or absence of FL thrombosis.Three measurement points were established in advance for the entire aorta:A represented the point located at pulmonary artery bifurcate,B was located by projecting the first axial section passing through the diaphragm and point C by projecting the first section passing under the left main renal artery.2.Data statistic:Set up data base about all the measurements,we use the CHISS statistical software to analysis data.Results:Level A:The true lumen diameter kept increasing and significantly increased at 1 month after EVR;the false lumen decreased significantly 1 month and 6 months after EVR,24 months after EVR,increase were seen,however it has no significance,diameter of aorta decreased significantly 1 month after EVR and kept decreasing thereafter.Level B:The true lumen diameter significantly increased at 1 month after EVR,it remains stable during 3-6 months,and kept increasing thereafter;the false lumen decreased significantly 1 month;the whole aorta significantly decreased at 1 month after EVR,then it remained stable.Level C:The true lumen kept increasing;the false lumen decreased in 6 months, then it increased gradually,abdominal aorta would increase to aneurysm.Conclusion:The effect of EVR in the thoracic aorta is definitive,complete FL thrombosis,FL diameters decrease and TL diameters increase were noted in most patients in this segment;Persistent flow into the false lumen,mainly due to entry tears at the abdominal level,was the cause of increased aorta,TL and FL diameters.Close follow-up is mandatory to evaluate the necessity of adjunctive procedures.