退变性腰椎侧凸患者腹主动脉与腰椎椎体相对位置的影像学测量

The position of the abdominal aorta relative to lumbar vertebrae in patients with degenerative lumbar scoliosis

中文关键词:  退变性腰椎侧凸  腹主动脉  主动脉-椎体角度  主动脉-椎体距离  旋转角度

英文关键词:Degenerative lumbar scoliosis  Abdominal aorta  Aorta-vertebrae angle  Aorta-vertebrae distance  Rotation angle

中文摘要:

  【摘要】 目的：探讨退变性腰椎侧凸（degenerative lumbar scoliosis，DLS）患者腰椎左侧凸和右侧凸情况下，腹主动脉与腰椎椎体的解剖关系。方法：回顾性分析我院2015年1月~2018年6月142例DLS患者和132例无脊柱侧凸的正常人群（对照组），DLS患者包含80例左侧凸患者（左侧凸组）和62例右侧凸患者（右侧凸组），观察对象均处于矢状位平衡，两组在性别、年龄和体重指数（body mass index，BMI）上与对照组匹配。通过X线片测量DLS患者腰椎侧凸方向、Cobb角、顶椎位置及冠状位偏移距离；通过MRI T1加权像建立笛卡尔坐标系，测量主动脉-椎体角度（α）、旋转角度（γ）、主动脉-椎体距离（d）及主动脉后壁-椎体前缘间隙（Int）。α、γ、d和Int分别在左侧凸组与对照组、右侧凸组与对照组的组间对比采用独立样本t检验；Cobb角及冠状位偏移距离与α、γ、d和Int的相关性检验采用Pearson相关分析。结果：左侧凸组Cobb角为23.7°±12.7°（10.4°～42.5°），冠状位偏移距离为45.2±10.7mm（25.5～77.7mm）；右侧凸组Cobb角为20.8°±10.4°（11.0°～48.4°），冠状位偏移距离为47.8±15.1mm（25.4～77.5mm），两侧凸组的顶椎分布（P=0.280）、Cobb角（P=0.311）和冠状位偏移距离（P=0.394）均无统计学差异。对照组α平均为-2.96°±6.40°，从T12~L4逐渐减小，而左侧凸组α（-2.57°±6.14°）无该规律，两组α比较无统计学差异（P=0.554）；左侧凸组γ平均为5.57°±5.32°；左侧凸组d（4.62±0.57cm）自T12~L4逐渐增大，且与对照组（4.44±0.43cm）比较有统计学差异（P＜0.001）；左侧凸组Int与对照组比较无统计学差异（P=0.832），即相对于正常人群，DLS左侧凸患者腹主动脉相对于椎体角度无改变，但距离稍远离左侧椎体。右侧凸组α（-3.41°±9.44°）自T12~L4逐渐减小，与对照组比较无统计学差异（P=0.762）；γ为-9.02°±6.71°；d为4.54±1.84cm，与对照组比较无统计学差异（P=0.530）；Int与对照组比较无统计学差异（P=0.807），即相对于对照组，DLS右侧凸患者腹主动脉与椎体的角度和距离无明显变化。Pearson相关分析显示，左侧凸组和右侧凸组Cobb角和冠状位偏倚距离与γ均存在相关性（均为P＜0.001），而与α、d和Int无明确相关性。结论：DLS右侧凸患者腹主动脉与椎体相对位置维持正常的解剖关系，左侧凸患者腹主动脉稍远离左侧椎弓根。DLS患者腹主动脉与腰椎相对解剖关系较正常人变化不大，但腰椎手术尤其是侧凸矫形过程中仍需要警惕腹主动脉损伤。

英文摘要:

  【Abstract】 Objectives: To investigate the anatomic position of the abdominal aorta relative to spine in degenerative lumbar scoliosis(DLS) patients with left or right lumbar scoliosis. Methods: A retrospective analysis was performed in 142 patients with DLS and 132 patients without spine deformity(control group) from January 2015 to June 2018 in our hospital. The DLS patients were divided into 80 cases with left lumbar scoliosis(left group) and 62 cases of right scoliosis(right group), which were matched to control group in terms of gender, age and body mass index(BMI). Direction of lumbar scoliosis(left or right), Cobb angle, apical vertebra position and coronal trunk shift were measured by using X-ray plain radiography in DLS patients. The measurements of aorta-vertebra angle(α), rotation angle(γ), aorta-vertebra distance(d) and the interval between anterior vertebral cortex and posterior aorta wall(Int) for each level at T12-L4 were obtained by using a Cartesian coordinate system established based on T1-weighted cross-sectional images of MRI. Independent sample t test was performed on comparison of α, γ, d and Int between the left group and control group, as well as the right group and control group, then Pearson correlation analysis was used to investigate the association between the Cobb angle and the coronal and α, γ, d and Int of the two scoliosis groups. Results: The average Cobb angle was 23.7°±12.7°(10.4°-42.5°) and the coronal horizontal displacement distance was 45.2±10.7mm(25.5-77.7mm) in the left group while they were 20.8°±10.4°(11.0°-48.4°) and 47.8±15.1mm(25.4-77.5mm) respectively in the right group, and there were no statistical differences in the apical vertebra position(P=0.280), Cobb angle(P=0.311) and coronal trunk shift(P=0.394) between the two scoliosis groups. The mean angle α(-2.96°±6.40°) gradually decreased from T12 to L4 in the control group while irregular in the left group(-2.57°±6.14°) and there was no difference between the two groups(P=0.554). The mean γ was 5.57°±5.32° and the mean d was 4.62±0.57cm with a gradual increase from T12 to L4 and with statistical difference with control group(4.44±0.43cm)(P<0.001) but with no difference in Int(P=0.832). Thus, the abdominal aorta had no statistical angle change but a slightly longer distance away from lumbar vertebrae in left scoliosis compared with the normal ones. That mean α (-3.41°±9.44°) gradually decreasing from T12 to L4 in right group was of no statistical difference with the control group(P=0.762). The mean γ was -9.02°±6.71° and the mean d was 4.54±1.84cm, with no difference with the control group(P=0.530) as well as Int(P=0.807). Therefore, there was no significant variation in the angle and distance between the abdominal aorta and vertebrae in right curvature of DLS compared with the control group. Pearson correlation analysis showed that there was a correlation between rotation angle γ and Cobb angle along with coronal horizontal displacement distance(both P<0.001), regardless of the left or right scoliosis, but not in α, d and Int. Conclusions: In the right group, a relative normal position relationship is maintained between the abdominal aorta and vertebrae while the aorta is slightly away from the left pedicle in left scoliosis patients. Although not so much difference of the relative position between DLS and normal people is found in this study, it is still of necessity to be alert to aorta injury.