| Bicuspid aortic valve (BAV) is one of the most common congenital heart diseases. Incidence rate is about0.9%-2%, ratio of male/female approximately reaches3:1,54%of patients aged over15come out with aortic stenosis (AS). Due to relationship between BAV and AS, aortic regurgitation (AR), aortic dissection and bacterial endocarditis (BE), BAV becomes a challenge of clinical physicians.BAV is structured of two leaflets, and the larger one could be charactered as fusion of right-left coronary cusps (BAV RL) and right-non coronary cusps (BAV RN). The BAV RL is associated with aortic coarctation (50%-75%of aortic coarctation accompanied by BAV), and the BAV RN is correlated with cuspal pathology.Series of studies have demonstrated that BAV is associated with abnormal gene and heredity. Emanuel et al found that incidence rate of BAV was14.6%in BAV families, and9.1%in first generation of relatives, which both exceeded that of population. Mutation of ACTA2in lOq, which encodes a-actin in smooth muscle cell, could induce generation and development of aneurysm of thoracic aorta and BAV.Diagnosis of BAV mainly depends on transthoracic echocardiographic (TTE) manifestation, including bicuspid construction, pseudo-raphe in the larger cusp, valvular thickening and calcification and eccentric commissure. But the most valuable findings are fish-mouth construction at diastole at short-axis view and doming of leaflet at systole at long-axis view. Furthermore, transesophageal echocardiography (TEE) could improve diagnostic accuracy. It is recommended that carry TTE for asymptomatic patients every two years and every year for symptomatic patients.The most common pathology of BAV is aortic stenosis, which deteriorates due to calcification, which mostly come out after40years old and is induced by long-term shear stress of free margin, dysfunction of endothelium, lipid deposition and secondary inflammation. Aortic regurgitation is the second common pathology.13% of BAV patients who underwent surgical aortic valve replacement suffered from aortic regurgitation. Interventions on dysfunctional aortic valve include balloon valvularplasty, surgical valve replacement, ROSS procedure and valvular repairment. The age of BAV patients who needed surgical interventions is younger than that of tricuspid aortic valve patients.Almost50%of BAV patients were accompanied by pathologies other than valve dysfunction, ascending aorta dilation is the most common one. Almost30%of BAV patients who underwent AVR should be given aortic interventions simutaneously, including aorta reinforcing or replacement. Aorta dilation is partially induced by abnormal hameodynamics, and due to molecular alterations which were detected in recent several researches. These alterations contained decreased fibrillin, fractured elastin and cellular apoptosis. It is reported that lack of Fibrillin-1could facilitate dissection of smooth muscle cell, lysis of extracellular matrix and apoptosis, in advantage of matrix metalloproteinases.Surgical interventions are effective for ascending aorta dilation and aortic dissection, and include reduction aortaplasty (with or without wrap augmentation), supra-sinus ascending aorta replacement, ascending aorta replacement with sinus resection and remodeling, valve-sparing root replacement, aortic root replacement with a valved conduit. As recommended, aorta with a diameter over50mm should be replaced, and45mm is the threshold if valve replacement is carried meanwhile. Yearly increase of diameter over5mm is also indication of surgical intervention. Anyway, aortic interventions possess higher risk, it was reported that ratio of mortality of AVR with ascending aorta replacement to mortality of simple AVR is2.78, and mortalities of surgeries on aortic dissection ranged from7%to30%. Furthermore, the secondary aortic incidences are rare after simple AVR for BAV patients.It is commonly accepted that Bentall procedure is essential for BAV patients with dilated aortic sinus (diameter>45mm), but is it essential for BAV patients with dilated ascending aorta without dilated sinus, there are different opinions in cardiac surgery centers. In this retrospective study, we are prone to review the medical records of BAV patients who underwent AVR and aortic surgeries, including Wheat procedure, Bentall procedure and reduction aortaplasty. With the help of SPSS20, we would try to find out risk factors of aortic sinus dilation, compare the prognosis of these three surgeries. If possible, follow up the development of aortic sinus in patients who underwent Wheat procedure and reduction aortaplasty. PART1Study on risk factors of aortic sinus dilation with bicuspid aortic valveObjective:Aortic dilation usually begins at the proximal tubular ascending aorta. This part, we investigate the risk factors of sinus dilation, in advantage of reviewing medical records of BAV patients with dilated ascending aorta.Methods:Include all the BAV patients with dilated ascending aorta who need surgical intervention from Jan1,2003to May4,2011. We exclude patients accompanied by aortic dissection and without echocardiographic report. Divide these patients into Group Dilation (>=45mm) and Group Non-Dilation (<45mm) according to sinus diameters and proceed statistical analysis in SPSS20.Outcomes:in univariate analysis, Group Dilation are younger and higher, and possess higher proportion of male and fusion of right-left coronary cusps, more severe aortic regurgitation, larger left ventricular diameters and higher elevation of total bilirubin, conjugated bilirubin and creatinine, but shorter duration of symptoms, less aortic stenosis, lower ejection fraction and lower elevation of white blood cell. In multivariate analysis with logistic regression model, less aortic stenosis and larger left ventricular end-diastolic diameter are the significantly risks of sinus dilation. It’s demonstrated in ROC curve analysis, that left ventricular systolic diameter and diastolic diameter are the two most valuable parameters indicating sinus dilation, the sensitivity and specificity is0.93,0.83while left ventricular diastolic diameter>60mm and0.79,0.89while systolic diameter>45.50mm.Conclusion:multivariate analysis demonstrates that less aortic stenosis and larger left ventricular end-diastolic diameter are the significantly risks of sinus dilation. The left ventricular systolic and diastolic diameters are the valuable parameters indicating sinus dilation. PART2Risk comparison of Wheat, Bentall procedure and reduction aortaplasty in bicuspid aortic valveObjective:in this retrospective study, we would discuss the protocol of surgeries selection and investigate difficulties and risk of Wheat, Bentall procedure and reduction aortaplasty.Methods:Include all the BAV patients with dilated ascending aorta who need surgical intervention from Jan1,2003to May4,2011. We exclude patients accompanied by aortic dissection and without echocardiographic report and divide accepted patients into Group Wheat, Group Bentall and Group Aortaplasty. We contein all the related complications and carry statistical analysis in SPSS20.Outcomes:Compared to Group Wheat and Group Aortaplasty, Group Bentall were younger but needed longer extracorporeal circulation and cross clamp time. Group Bentall need longer ventilator support than Group Aortaplasty. There’s no difference on ICU consumption among three groups. Elevations of total bilirubin, conjugated bilirubin and creatinine one day after surgery in Group Bentall are significantly more than those in the other two groups. Group Aortaplasty possess significantly less total drainage than the other two groups along with the least blood plasma consumption, while every member in Group Bentall has a history of blood products consumption. Anyway, all the patients survived the surgeries and there’s no difference in complication and length of stay among these three groups.Conclusion:Although Group Bentall expend more operation time and blood products consumption, there is no significantly more complication and longer length of stay, securities in these group are mainly coincident. PART3Follow-up study of aortic intervention on patients of biscuspid aortic valve and aortic dilationObjective:we retrospectively reviewed the information of bicuspid aortic valve patients with aortic dilation who underwent aortic intervention. Follow up the cardiac death and aortic incidences.Method:Include all the BAV patients with dilated ascending aorta who need surgical intervention from Jan1,2003to May4,2011. Follow up and get information on survival, major adverse cardiac events and aortic incidences.Outcomes:96.4%of the patients followed up and the last follow-up time was38.14±23.65months after operation. There were4deaths,7major adverse cardiac events and6aortic incidences. Kaplan-Meier analysis suggested that survival rate was97.3±1.9%at1year after operation,85.2±10.3%at6years; freedom from major adverse cardiac events was96.0±2.3%at13months,80.2±11.1%ar73months; freedom from aortic incidences was94.9±2.9%at33months,86.2±6.7%at65months.Conclusion:survival rate, freedom from major adverse cardiac events and aortic incidences after aortic interventions on bicuspid aortic valve patients with aortic dialtion are acceptable, there’s on significant diffenrence among different surgeries. We suggest active aortic interventions. |
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