Anatomic characteristics of ruptured abdominal aortic aneurysm on conventional CT scans: Implications for rupture risk
Anatomic characteristics of ruptured abdominal aortic aneurysm on conventional CT scans: Implications for rupture risk
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DOI：
10.1016/j.jvs.2004.02.025
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发表时间：
2004-06-01
影响因子：
4.3
通讯作者：
Rzucidlo, EM
中科院分区：
文献类型：
--
作者：
Fillinger, MF;Racusin, J;Rzucidlo, EM
目的：本研究的目的是分析腹主动脉瘤破裂（AAAs）患者的解剖特征，并通过常规二维计算机断层扫描（CT）与年龄、性别、体型匹配的对照组进行比较。方法：回顾记录，确定在达特茅斯-希区柯克医疗中心或转诊医院因破裂或急性剧烈疼痛（RUP组）进行紧急AAA修复之前获得的所有CT扫描。在选择性AAA修复（ELEC组）之前获得的CT扫描与RUP组患者的年龄和性别相匹配。每次CT扫描测量了40多个变量。动脉瘤直径匹配是通过连续删除最大的RUP扫描和最小的ELEC扫描来实现的，以防止偏差。对259例AAAs患者的CT扫描进行了分析：122例RUP和137例ELEC。患者的年龄、性别和其他人口统计学变量或危险因素匹配良好。所有患者的最大AAA直径比较有显著差异（RUP, 6.5 +/- 2 cm vs ELEC, 5.6 +/- 1 cm, P < 0.0001），女性患者破裂的AAA直径平均小于5mm （6.1 +/- 2 cm vs 6.6 +/- 2 cm, P = 0.007）。200例患者根据直径、性别和年龄进行匹配（每组100例；最大AAA直径，6.0 +/- 1 cm vs 6.0 +/- 1 cm）。直径匹配AAAs分析显示，两组患者肾下颈长（17 +/- 1mm vs 19 +/- 1mm, P = .3）、最大血栓厚度（25 +/- 1mm vs 23 +/- 1mm, P = .4）、体质指标([（最大AAA直径）/（正常肾上主动脉直径）]或[（最大AAA直径）/（L3横径）]等多数变量在统计学上相似。控制性别的多因素分析表明，导致主动脉破裂的最重要变量是主动脉弯曲（优势比[OR] 3.3，表明没有或轻微弯曲的风险更大）、直径不对称（优势比为3.2，主次轴差为1厘米）和当前吸烟（优势比为2.7，当前吸烟者风险更大）。结论：当年龄、性别和直径相匹配时，破裂的AAAs弯曲程度较低，但截面直径不对称程度较大。常规二维CT轴位切片显示，当直径不对称伴主动脉低扭曲时，轴位切片直径越大更准确反映主动脉破裂风险，而当直径不对称伴主动脉中重度扭曲时，轴位切片直径越小更准确反映主动脉破裂风险。即使在控制性别和AAA解剖结构的情况下，当前吸烟与破裂显著相关。
Objective: The purpose of this study was to analyze anatomic characteristics of patients with ruptured abdominal aortic aneurysms (AAAs), with conventional two-dimensional computed tomography (CT), including comparison with-control subjects matched for age, gender, and size.Methods: Records were reviewed to identify all CT scans obtained at Dartmouth-Hitchcock Medical Center or referring hospitals before emergency AAA repair performed because of rupture or acute severe pain (RUP group). CT scans obtained before elective AAA repair (ELEC group) were reviewed for age and gender match with patients in the RUP group. More than 40 variables were measured on each CT scan. Aneurysm diameter matching was achieved by consecutively deleting the largest RUP scan and the smallest ELEC scan to prevent bias.Results. CT scans were analyzed for 259 patients with AAAs: 122 RUP and 137 ELEC. Patients were well matched for age, gender, and other demographic variables or risk factors. Maximum AAA diameter was significantly different in comparisons of all patients (RUP, 6.5 +/- 2 cm vs ELEC, 5.6 +/- 1 cm; P < .0001), and mean diameter of ruptured AAAs P,vas 5 mm smaller in female patients (6.1 +/- 2 cm vs 6.6 +/- 2 cm; P = .007). Two hundred patients were matched for diameter, gender, and age (100 from each group; maximum AAA diameter, 6.0 +/- 1 cm vs 6.0 +/- 1 cm). Analysis of diameter-matched AAAs indicated that most variables were statistically similar in the two groups, including infrarenal neck length (17 +/- 1 mm vs 19 +/- 1 mm; P = .3), maximum thrombus thickness (25 +/- 1 mm vs 23 +/- 1 mm, P = .4), and indices of body habitus, such as [(maximum AAA diameter)/(normal suprarenal aorta diameter)] or [(maximum AAA diameter)/(L3 transverse diameter)]. Multivariate analysis controlling for gender indicated that the most significant variables for rupture were aortic tortuosity (odds ratio [OR] 3.3, indicating greater risk with no or mild tortuosity), diameter asymmetry (OR, 3.2 for a 1-cm difference in major-minor axis), and current smoking (OR, 2.7, with the greater risk in current smokers).Conclusions: When matched for age, gender, and diameter, ruptured AAAs tend to be less tortuous, yet have greater cross-sectional diameter asymmetry. On conventional two-dimensional CT axial sections, it appears that when diameter asymmetry is associated with low aortic tortuosity, the larger diameter on axial sections more accurately reflects rupture risk, and when diameter asymmetry is associated with moderate or severe aortic tortuosity, the smaller diameter on axial sections more accurately reflects rupture risk. Current smoking is significantly associated with rupture, even when controlling for gender and AAA anatomy.