Nvestigate On The Correlations Between The Time Of Thoracic Endovascular Aortic Repair And Prognosis In Patients With Acute Stanford Type B Aortic Dissection

ObjectiveThoracic endovascular aortic repair (TEVAR) is the first choice of therapies for the treatment of acute Stanford type B aortic dissection (AADB), but the correlations between the efficiency and the time of TEVAR is not clarified yet. The study is to investigate the correlations between the time of TEVAR and prognosis in patients with AADB.Methods1. Study population and groupsThe clinical data of AADB patients with TEVAR, who were hospitalized from January2008to December2012in five hospitals of Guangdong Provence, was retrospectively analyzed. The status of aortic reconstruction at three months after TEVAR, mortalities of in-hospital and follow-up, mean hospital expense and length of stay were compared among the three groups.Totally156patients were included, who were divided into three groups according to the time from symptom onset to TEVAR:less than one week was defined as group A (n=87), one to two weeks was group B (n=48),more than two weeks was group C (n=21).2. Study methods2.1Measurement of thoraco-abdominal aortic parametersAortic CTA was obtained from image software system. Before TEVAR, smallest true lumen diameter and largest false lumen diameter were measured with the online measurement tools, at3±1months after TEVAR, largest true lumen diameter and largest false lumen diameter were measured and proximal and distal tears, endoleak and retrograde tear were also inspected.2.2TEVAR procedure On the basis of standard medical treatment, all of the patients received TEVAR. The criteria of a successful TEVAR procedure was that proximal tear was covered completely without endoleak or with a slight endoleak and no meaningless endoleak and no importance branch vessels was covered, which caused serious ischemia.2.3Basic clinical dataClinical data were recorded, which include patients’age, sex, hypertension, smoking history, renal function before TEVAR, the time from symptom onset to TEVAR, the time of symptom onset, the time of TEVAR, length of stay, hospital expense, abdominal branch vessels involved by aortic dissection, slight endoleak after TEVAR and distal entry.2.4Follow up①Aortic remodeling was evaluated by aortic CTA at3±1months after TEVAR.②Follow up by clinic or telephone to record the following information: survival status, survival time, cause of death, blood pressure level and recurence of aortic dissection.Results1. There was no significant differences in age, sex, hypertension, smoking history, renal function before TEVAR, abdominal branch vessels (renal artery, mesenteric artery, lilac artery, celiac) involved by aortic dissection, a slight endoleak after TEVAR, distal entry between the three groups (P>0.05). The time from symptom onset to TEVAR in the three groups were3.2±2.2days,9.8±1.8days and17.9±3.1days, respectively (P<0.05).2. The length of stay in group A (16.0±12.2days) and group B(17.1±7.3days) were significant shorter than in group C(24.7±8.3, P<0.05days). Hospital expenses of group A (140±50thousand yuan) and group B (130±30thousand yuan) were remarkable less than that of group C (150±40thousand yuan, P<0.05). Compared with that of group C, each patient of group B saved20thousand Yuan.3. Before TEVAR, there was no significant differences in the ratio of smallest true lumen diameter and largest false lumen diameter between the three groups (0.47±0.33,0.42±0.18,0.47±0.27, respectively, P>0.05). Totally123patients were followed up with aortic CTA at3±1months after TEVAR, and distal false lumen was find in111patients (90.2%,62from group A,36from group B and13from group C). At3±1months after TEVAR, the ratio of largest true lumen diameter and largest false lumen diameter between the three groups was significantly greater in group A (1.76±0.51) than group (1.42±0.30) and group C(1.34±0.34, P<0.05),when there was no significant difference between the latter two groups. The Pearson bivariate correlation showed that ratio of smallest true lumen diameter and largest false lumen diameter before TEVAR and the time from symptom onset to TEVAR was significantly negative correlated (r=-0.619, P<0.05). The ratio of largest true lumen diameter and largest false lumen diameter during follow up was significantly negative correlated with the time from symptom onset to TEVAR (r=-0.332, p=0.000).The status of aortic remodeling:at3±1months after TEVAR, aortic CTA showed that12slight endoleaks after procedure were disappeared. Completely aortic reconstruction was achieved in12patients,8were from group A and4from group B, but no patient was from group C.4. Complications:the defined preoperative complication included acute renal dysfunction, stroke, intestinal ischemic, lower limb ischemic, paraplegia and sudden death. The general trend of complications in the three groups gradually increased as the time from symptom onset to TEVAR prolonged, but there were no significant differences (20.7%,31.3%,38.1%, respectively, P>0.05). However, the incidence of stroke complication in group B(12.5%) was much higher than in group A(1.1%) and in group C (4,8%, P<0.05). Paraplegia in group C (4.8%) was much higher than in group A (0) and in group B (0, P=0.038). Renal dysfunction in group C (23.8%) was much higher than in group A(11.5%) and in group B(14.5%), but there were no significant differences.5. In-hospital death:8patients died during hospitalization, all of them were from group A and group B. Two patients died from proximal aortic dissection and five from visceral ischemia (2from intestinal ischemic and3acute renal dysfunction). The five patients’ conditions continually worsen before the procedure and emergency TEVAR had to be carried out. Those patients were hardly to live longer if without emergency TEVAR. Therefore, there was no relationship between their death and TEVAR. One patient underwent sudden death before planned discharge.6. Follow up:At least three months after TEVAR, parts of survival discharged patients (131,88.51%) were followed up. The time from symptom onset to survival was25±19months. Four patients died during follow up (1from group A,1from group B and2from group C). One of them died from aortic rupture, three of them died from other disease which was not related with aortas. Endoleak was found in3patients during follow up. Among them, two patients with type IIendoleak were from group B and one case with type I endoleak was from group C. One retrograde teary from group A required surgery treatment. There was no significant difference in the blood controlling between the three groups.Conclusions1. For the AADB patients, the ratio of smallest true lumen diameter and largest false lumen diameter before TEVAR and the ratio of largest true lumen diameter and largest false lumen diameter after TEVAR can be used to evaluate the change of true-false lumen diameter in aortic dissection and aortic remodeling, which might be more reliable than diameters of true or false lumen themselves.2. This study showed that compared with the current guideline recommendation, in which TEVAR should be undergone in two weeks after symptom onset in stable patients, earlier TEVAR for AADB was safe and beneficial for aortic remodeling, less complications, lower the hospital expense and shorter length of stay.