The Strategy And Clinical Study Of Stanford B Aortic Dissection

The Strategy and Clinical Study of Stanford B Aortic Dissection ObjectiveThe optimal treatment for Stanford B dissections remains controversial. Today, the anti-impulsive and antihypertensive combination therapy remains the cornerstone of modern medical management of type B-AD. Patients with intractable pain, organ ischemia or rupture were mostly treated surgically. Unfortunately, aneurysmal dilation of the false lumen will develop in 25%to 40%of medically managed patients<5 years. Indeed, up to 20%of these patients can present with or later experience severe complications, such as rupture, impending rupture, or branch-vessel malperfusion. More recently, endovascular stent graft treatment of B type aortic dissections has been used as a potentially minimally invasive alternative and made great progress. Surgical repair for B type dissection also improve greatly duo to the technique of cerebrospinal fluid drainage, profound hypothermia, Somatosensory Cortical Evoked Potentials/Motor Evoked Potential and so on. Basis on Stanford classification, refined subtype aortic dissection to determine the indication, optimal operative procedures, plan and the estimation of the prognosis, aiming to evalauate the advantages of this refined classification for type B dissection.MethodsWith the approval of the Institutional Review Committee,329 consecutive adult patients undergoing aortic surgery from January 2002 to 2009 were reviewed retrospectively. Demographic Characteristics and Preoperative and intraoperative data were recorded. Type B dissection can be classified into 3 subtypes based on dilated extension of proximal descending aorta. Type B1 r no dilation was confined in the proximal of thoracic descending aorta):Type B2 (aneurysm in thoracic descending aorta):Type B3 (aneurysm in thoracic descending and abdominal aorta):Type BC (complex type):Type BS(simple type). All patients underwent a complete preoperative investigation. Chest-X ray, enhanced computed tomography (CT) and echocardiography were performed so as to select the appropriate surgical management. Informed consents were obtained from all patients. The following preoperative variables were evaluated: age, sex, body mass index, aortic dissection, Marfan syndrome, history of hypertension, diabetes mellitus, chronic obstructive pulmonary disease (COPD), smoking, reoperation, New York Heart Association classification, hemoglobin, serum albumin, serum creatinine, international normalized ratio, and urgency of procedure. Intraoperative variables analyzed were inotropes, DHCA time, myocardial ischemia time, CPB time, blood components transfused during surgery, and additional procedures. Major postoperative outcomes including in-hospital mortality, stroke, renal failure requiring dialysis, reintubation, re-exploration for bleeding, and intensive care unit (ICU) and in-hospital length of stay were also analyzed. All statistical analyses were performed by SPSS version 13.0 (SPSS, Chicago, IL) and a p value<0.05 was significant. The continuous variables were presented as mean±standard deviation for normally distributed data and as median and interquartile range for non-normally distributed data. The categorical data were presented as numbers and percentages. Descriptive statistics including continuous and categorical variables were analyzed with a Student t test or Mann-Whitney U test and chi-square test or Fisher exact test. The patients were followed by using enhanced electron beam computed tomography (CT) before discharge, at 3 months post-operatively and annually thereafter. Complications such as neurological, renal and respiratory morbidity were recorded.ResultsIn part I, there were 174 patients who underwent thoracic endovascular aortic repair (TEVAR) in the management of type B aortic dissection. Primary technical success was achieved in 100%of patients. Early mortality occurred in two patients (one died of aortic rupture,the other died of multiple organ failure. there were 155 patients underwent surgical repair. early mortality was 3.8%.Death reason include renal failure, MODS, anoxic encephalopathy. Pulmonary complications—the most common form of morbidity—occurred in 16 patients (10.3%). Other complications included stroke in 2 patients(1.3%), renal failure requiring hemodialysis in 5 patients (3.2%),bleeding required reoperation in 10 patients(6.5%),Spinal Cord injury in 4 patients(2.6%). During following up period, there were 3 late death in TEVAR group,4 late death in surgical repair group. Survival rate in 1 year.3 year,5 year were 98.3%,97.8%,97.1% respectively. In partⅡ, To summarize the experience in one stage total thoracoabdominal aorta replacement with four branch vessel prosthesis for treatment of B3 type aortic dissection.1 patients died during the early post-operational period.6 patients showed cerebral complications with an incidence of 13.6%and were cured after hydration therapy. Pulmonary complications occurred in 9 patients ( 20.5%). Paraplegia occurred in 2 patients. In multivariate analysis, predictors of cerebral complications and pulmonary complications were found to be excessive blood products transfusion. In partⅢ, We performed total arch replacement with stented elephant trunk procedure for these complicated Stanford type B aortic dissection, aiming to evaluate the advantages of this techniques. Forty-three patients underwent the surgical repair. The procedure was successful in all patients but three patients died of multiple organ failure after the operation. Compared with the data preoperatively, the diameter of the true lumen of proximal descending aorta was expanding significantly:13.9±4.93mm vs28.5±24.6mm (n=40, P<0.05).During following up period, false lumen were thrombus and shrinkaged.ConclusionsThe refine subtype of Stanford B aortic dissection is much useful in determining the optimal procedure operative indication and plan. estimating the prognosis. Using tetrafurcate graft is a reliable method in total thoracoabdominal aortic replacement and has a satisfactory mid-term result. Total arch replacement with stented elephant trunk procedure could be a recommendable option for complicated type B dissection with a low morbidity and mortality rate. Moreover, the mid-term efficacy of the procedure in closing the residual false lumen of the descending aorta is satisfying.