Yale University School of Medicine, New Haven, CT.
Division of Vascular and Endovascular Surgery, Department of Surgery, Yale University School of Medicine, New Haven, CT.
Ann Vasc Surg. 2023 Aug;94:165-171. doi: 10.1016/j.avsg.2023.03.018. Epub 2023 Apr 5.
Median arcuate ligament syndrome (MALS) is a clinical syndrome caused by compression of the celiac artery by the median arcuate ligament that often manifests with nonspecific abdominal pain. Identification of this syndrome is often dependent on imaging of compression and upward bending of the celiac artery by lateral computed tomography angiography, the so-called "hook sign." The purpose of this study was to assess the relationship of radiologic characteristics of the celiac artery to clinically relevant MALS.
An institutional review board-approved retrospective chart review from 2,000 to 2,021 of 293 patients at a tertiary academic center diagnosed with celiac artery compression (CAC) was performed. Patient demographics and symptoms of 69 patients who were diagnosed with symptomatic MALS were compared to 224 patients without MALS (but with CAC) per electronic medical record review. Computed tomography angiography images were reviewed and the fold angle (FA) was measured. The presence of a hook sign (defined as a visual FA < 135°), as well as stenosis (defined as >50% of luminal narrowing on imaging) were recorded. Wilcoxon rank-sum test and Chi-squared test were used for comparative analysis. Logistic model was run to relate the presence of MALS with comorbidities and radiographic findings.
Imaging was available in 59 patients (25 males, 34 females) and 157 patients (60 males, 97 females) with and without MALS, respectively. Patients with MALS were more likely to have a more severe FA (120.7 ± 33.6 vs. 134.8 ± 27.9, P = 0.002). Males with MALS were also more likely to have a more severe FA compared with males without MALS (111.1 ± 33.7 vs. 130.4 ± 30.4, P = 0.015). In patients with body mass index (BMI) >25, MALS patients also had narrower FA compared with patients without MALS (112.6 ± 30.5 vs. 131.7 ± 30.3, P = 0.001). The FA was negatively correlated with BMI in patients with CAC. The hook sign and stenosis were associated with diagnosis of MALS (59.3% vs. 28.7%, P < 0.001, and 75.7% vs. 45.2%, P < 0.001, respectively). In logistic regression, pain, stenosis, and a narrow FA were statistically significant predictors of the presence of MALS.
The upward deflection of the celiac artery in patients with MALS is more severe compared with patients without MALS. Consistent with prior literature, this bending of the celiac artery is negatively correlated with BMI in patients with and without MALS. When demographic variables and comorbidities are considered, a narrow FA is a statistically significant predictor of MALS. Regardless of MALS diagnosis, a hook sign was associated with narrower FA. While demographics and imaging findings may inform MALS diagnosis, clinicians should not rely on a visual assessment of a hook sign but should quantitatively measure the anatomic bending angle of the celiac artery to assist with the diagnosis and understand the outcomes.
中位弓状韧带综合征（MALS）是一种由中位弓状韧带压迫腹腔动脉引起的临床综合征，常表现为非特异性腹痛。这种综合征的识别通常依赖于影像学检查，即通过侧位计算机断层血管造影（CTA）显示腹腔动脉受压和向上弯曲，即所谓的“钩状征”。本研究旨在评估腹腔动脉的影像学特征与临床相关的 MALS 的关系。
对 2000 年至 2021 年在一家三级学术中心接受诊断为腹腔动脉压迫（CAC）的 293 例患者进行了机构审查委员会批准的回顾性图表审查。通过电子病历回顾，比较了 69 例诊断为有症状 MALS 的患者和 224 例无症状但有 CAC 的患者的患者人口统计学和症状。对 CT 血管造影图像进行了回顾，并测量了折叠角（FA）。记录钩状征（定义为视觉 FA < 135°）和狭窄（定义为影像学上>50%的管腔狭窄）的存在情况。Wilcoxon 秩和检验和卡方检验用于比较分析。逻辑模型用于分析 MALS 与并存疾病和影像学发现之间的关系。
影像学资料可用于 59 例（25 例男性，34 例女性）和 157 例（60 例男性，97 例女性）有或无 MALS 的患者。有 MALS 的患者 FA 更严重（120.7 ± 33.6 比 134.8 ± 27.9，P = 0.002）。与无 MALS 的男性相比，有 MALS 的男性 FA 也更严重（111.1 ± 33.7 比 130.4 ± 30.4，P = 0.015）。在 BMI >25 的患者中，有 MALS 的患者 FA 也比无 MALS 的患者更窄（112.6 ± 30.5 比 131.7 ± 30.3，P = 0.001）。FA 与 CAC 患者的 BMI 呈负相关。钩状征和狭窄与 MALS 的诊断相关（59.3%比 28.7%，P < 0.001，75.7%比 45.2%，P < 0.001）。在逻辑回归中，疼痛、狭窄和狭窄的 FA 是 MALS 存在的统计学显著预测因子。
与无 MALS 的患者相比，有 MALS 的患者腹腔动脉向上偏转更严重。与既往文献一致，这种腹腔动脉的弯曲与有无 MALS 的患者的 BMI 呈负相关。考虑到人口统计学变量和并存疾病，狭窄的 FA 是 MALS 的统计学显著预测因子。无论是否存在 MALS 诊断，钩状征均与狭窄的 FA 相关。尽管人口统计学和影像学发现可能有助于 MALS 的诊断，但临床医生不应依赖于钩状征的视觉评估，而应定量测量腹腔动脉的解剖弯曲角度，以协助诊断和了解结果。
