The Anatomy And Function Study Of Aortic Root And Its Clinical Application

Part IThe diameters of aortic valve annulus and sinus-tube joint in the normal Han nationality adultsBackground The anatomic values of the aortic root are important for aortic valve repair. The main aim of this study is to determine the normal values of the diameters of the aortic valve annulus (AVA) and sinus-tube joint (STJ) in the healthy Chinese Han nationality adults, and to provide a morphological foundation to further potential clinical applications. Methods Echocardiography was performed in 326 normal subjects, which were divided into 5 groups according to their age. The diameters of AVA and STJ were measured in the parasternal long-axis view, and normalized to body surface area (BSA). Averages of these two diameters were calculated for every age group and for each gender. Differences between the normalized diameters for each age group and for both genders were then tested. The Pearson correlation coefficient between AVA and STJ diameters was first calculated. The Pearson correlation coefficient between the above two variables and age, BSA, weight, and height was also measured in order to determine any positive or negative correlations.Results The diameters of AVAs and STJs of Han nationality patients augmented with an increase in age, with BSA, weight and height. The correlation coefficient between AVA diameter and BSA was 0.4944 (P<0.0001); AVA diameter and age,0.1138 (p<0.05); AVA diameter and weight, 0.4521 (P<0.001); and AVA diameter and height,0.4713 (P<0.001). The correlation coefficient between STJ diameter and BSA was 0.3910 (P<0.0001); STJ diameter and age,0.3667 (P<0.0001); STJ diameter and weight,0.4586 (P<0.0001); and STJ diameter and height,0.3736 (P<0.0001). The difference between the above two diameters was found to be statistically significant at 2.42±2.45 mm (paired t-test; t=-17.25; P<0.0001). AVA and STJ diameters were similar in both genders of each group when indexed to BSA.Conclusion The diameters of the AVA and STJ of Chinese Han adults augmented with increasing age, BSA, weight and height. Diameters of the AVA and the STJ were similar in both genders, when indexed to BSA. The diameter of the AVA was less than that of the STJ by about 10%; the difference between the above two diameters was 2.42±2.45 mm.PartⅡDynamic normal aortic root diameters:implications for aortic root reconstructionBackground The main aim of this study is to determine the normal diameters and the relationships of aortic root components in the healthy adults, and to provide a morphological foundation for future clinical applications.Methods Echocardiography was performed in 314 normal subjects, who were divided into five groups according to the age. Dynamic aortic root diameters were measured and normalized to body surface area. Averages of these dynamic diameters were calculated for each age group and by gender, and differences between them were tested. Correlation coefficients were also determined between the dynamic diameters and age, body surface area, weight, and height. Aortic root diameters were also tested and compared between the end-diastole and the mid-systole.Results Normalized diameters for the dynamic aortic root varied among the age groups. There were apparent relationships between the dynamic diameters and age, body surface area, weight and height (p<0.01). The normalized diameters were similar between both genders within each age group (p>0.05)。Each part of the aortic root expanded and contracted proportionally and harmoniously during the cardiac cycle. The ratio of the aortic valve annulus to the sinus of Valsalva, the sinus-tube joint and the proximal ascending aorta were 0.70,0.85,and 0.78 at the end-diastole, respectively, and 0.71,0.85 and 0.78 at the mid-systole, respectively.Conclusion The dynamic diameters of aortic roots of healthy adults were augmented with an increase according to age, body surface area, weight and height. The results are of applicable value of aortic valve repair.Part IIIMid-term results of aortic root reconstruction with valve-sparing techniqueBackground The main aim of this study is to review the mid-term results of valve-sparing operations in patients with aortic root aneurysm, ascending aortic aneurysm, and acute ascending aortic dissection.Methods From May 2006 to Oct 2010 thirty-six patients were undertaken aortic root reconstruction with valve sparing. There were 29 males and 7 females with the age from 24 to 78 (average 57.8±15.9) years. The data of the cardiac function, the diameters of left ventricular and the degree of aortic valve regurgitation were collected before and after operation. Results There was no operative mortality and major morbidity. The average CPB time was 175.5±43.8 minutes, and the aortic cross-clamp time 130.5±38.3 minutes. During a mean follow-up of 31.6 month (8 to 50 month), the heart function of NYHA classification was improved significantly from 2.44±0.50 preoperatively to 1.47±0.51 postoperatively (P<0.05). The preoperative and postoperative LVEF were 0.63±0.10 and 0.64±0.13, respectively (P>0.05). The dimensions of LV cavity decreased significantly. The aortic valve regurgitation was decreased significantly from 2.72±0.74 preoperatively to 1.56±0.65 postoperatively (P<0.05).Conclusion Aortic root reconstruction with aortic valve sparing had provided satisfactory mid-term outcomes for aortic root aneurysm, ascending aortic aneurysm and dissection. Part IVThe effect of the aortic root movement in aortic valve openingBackground The main aim of this study is to measure the changes of the aortic root diameter in cardiac cycle in the healthy adults, and to elevate the relationship of the aortic root movement and cusps opening.Methods Echocardiography was performed in 56 normal subjects, including 32 males and 24 females with the age from 17 to 60 (average 39.96±12.23) years. The aortic root diameters were measured in the parasternal long-axis view, including four levels:annulus, sinus, sino-tube joint, ascending aorta. Five time points were chosen to measure in cardiac cycle: the beginning of the P wave, the beginning of the Q wave, the top of the R wave, the beginning of the T wave and the end of the T wave. Results The diameter of annulus at the beginning of the P wave, the beginning of the Q wave, the top of the R wave, the beginning of the T wave and the end of the T wave was 19.57±2.12mm,19.73±2.16mm, 20.54±2.20mm,20.10±3.18mm and 20.12±2.00mm separately. The difference of annulus diameter between the top of the R wave and the end of the T wave was significant (P<0.05). The other three levels diameters increased after the top of the R wave.Conclusion The annulus diameter of the health adults increased at the top of the R wave, the beginning of the isovolumic contraction period. After that, the aortic root distended during the systolic period.Part VA primary research of dynamic three dimensional aortic root modelBackground The main aim of this study is to reconstruct a primary dynamic three-dimensional aortic root model for further research. Methods We chose a healthy male with normal sinus rhythm, excluding the heart valve disease and congenital heart disease changing the flow through aortic root. The subject was performed multislice spiral CT scan. After ECG-gated reconstruction, the images were chosen on 8 points, which divided the cardiac cycle averagely. The three dimensional model of every point was reconstructed through computer processing.Results A set of aorta and aortic valve segmentation, reconstruction and display tools were developed based on IDL language. The individual three dimensional models of 8 points were processed according to the time sequence.Conclusion The dynamic three-dimensional aortic root model can be reconstructed with multislice spiral CT scan images.