Morphological Features Of Normal Aorta In Adult Chinese

Objective: To study the morphological features of aorta,and to establish the anatomical basis for the development of endovascular graft in ascending aorta and aortic arch and the improvement of endovascular repair technique,aortic CT angiography(CTA)was observed through a vascular imaging workstation and a series of measurements were made on the aorta and branching vessels of aortic arch.Methods: From Jan 2016 to Dec 2016,we retrospectively reviewed 240 patients undergoing aorta CTA in our institution.The aortic arch was divided into normal type and variant type.In each patient with normal type aortic arch,26 measurements were made in GE AW4.6 workstation,including diameters,lengths,distances,and angles of aorta.SPSS statistical software was used to analyze data.Results and analysis: Part one: Measurement and analysis of normal type aorta: 1.Aortic arch classification results:(1)Among the 240 patients,the normal type amount to 187 cases(77.92%),where the incidence rate of male was 79.22%,and of female was 75.58%.The variant type was 53 cases altogether,including 31 cases of BCT and LCCA in a common trunk,21 cases of LVA directly arising from aortic arch,1 case of BCT and LCCA in a common trunk combined with LVA directly arising from the aortic arch.(2)There were 93 cases of type I aortic arch in the 187 cases of normal type mentioned above,82 cases of type II and 12 cases of type III.The distribution of 3 types of aortic arch was not the same in all age groups.The aforementioned differences were statistically significant(P <0.05).2.Measurement of normal type aorta:(1)Aortic diameters: 20 mm distal to coronary artery(CA)ostia(D1)(32.74 ± 4.52)mm,40 mm distal to CA ostia(D2)(34.17 ± 4.90)mm,the level at the origin of brachiocephalic trunk(BCT)(D3)(32.11 ± 4.11)mm,the level between the BCT and the left common carotid artery(LCCA)(D4)(30.23 ± 3.95)mm,the leval between the LCCA and the left subclavian artery(LSA)(D5)(28.16 ± 3.30)mm,20 mm distal to LSA ostia(D6)(26.27 ± 3.35)mm.(2)Aortic lengths: CA-BCT(L1)(72.70 ± 12.80)mm,CA-LCCA(L2)(87.19 ± 14.02)mm,CA-LSA(L3)(103.48 ± 17.17)mm.(3)Aortic angles: ascending aortic curvature((37))(111.69 ± 14.25)°,the angle between the aortic arch and the sagittal plane(q)(23.83 ± 6.31)°.3.Statistical analysis of aorta parameters: Males had larger D6,L2 and L3 than females.D1 ~ D6,L2 and L3 increased with age when they in age groups of 19 ~ 40 y,41 ~ 60 y and 61y~.In the age groups of 41 ~ 60 y and 61y~,L1 were greater than in the age group of 19 ~ 40 y,while ? were smaller.In the age groups of 19 ~ 40 y and 41~ 60 y,q were greater than in the age group of 61y~.The aforementioned differences were of statistically significance(P<0.05).Part two: Measurement and analysis of branches of normal type aortic arch: 1.The measurements of branching vessels of normal type aortic arch:(1)Branching vessels' diameters: the level at the origin of BCT(d1)(15.31 ± 2.37)mm,20 mm distal to BCT ostia(d2)(12.45 ± 2.09)mm,the level at the origin of LCCA(d3)(11.86 ± 2.19)mm,20 mm distal to LCCA ostia(d4)(7.70 ± 1.19)mm,the level at the origin of LSA(d5)(13.62 ± 1.94)mm,20 mm distal to LSA ostia(d6)(9.36 ± 1.37)mm.(2)Branching vessels' lengths and distances: the length between the origin of BCT and right subclavian artery(RSA)(L4)(37.77 ± 9.18)mm,the length between the origin of LSA and the left vertebral artery(LVA)(L5)(42.78 ± 11.75)mm,the distance between the ostia of BCT and LCCA(S1)(4.04 ± 2.59)mm,the distance between the ostia of LCCA and LSA(S2)(8.71 ± 4.35)mm.(3)Angles formed by branching vessels with aortic arch: the angle between the BCT and arch(?)(29.54 ± 12.89)°,between the LCCA and arch(?)(40.57 ± 16.91)°,between the LSA and arch(?)(58.48 ± 21.80)°.(4)The relative positional parameters of the branching vessels of type I aortic arch: the angle formed by BCT,LCCA,and LSA(?)(144.44 ± 9.74)°,the distance between center of LCCA ostia and line between center of ostia of BCT and LSA(R)(4.60 ± 1.21)mm.2.Statistical analysis of branch parameters: Males had lager d3,d4,d5,d6,L4,L5 and S2 than females.In the age groups of 19 ~ 40 y,41 ~ 60 y and 61y~,d1,d2 and d4 increased with age,while ? and ? decreased with age.In the age groups of 41 ~ 60 y and 61y~,d3,d5,d6,S2 and R were larger than those in the age group of 19 ~ 40 y,while ? was smaller than that.In the age groups of 19 ~ 40 y and 41 ~ 60 y,L4 and L5 were shorter than those in the age group of 61 y.The aforementioned differences were statistically significant(P<0.05).By the measurement of 187 cases of normal type aorta,we obtained the detailed morphological parameters of ascending aorta,aortic arch and its branching vessels.And through gender and age stratification for statistical analysis,we found that some rules of the changes in aortic morphology have important clinical significance.These parameters can also provide detailed information for the design of new intravascular stent grafts and vascular prosthesis.