Prevalence and Characteristics of Patients with Median Arcuate Ligament Syndrome in a Cohort Diagnosed with Celiac Artery Compression

BACKGROUND

Median arcuate ligament syndrome (MALS) is a frequent differential diagnosis in patients with postprandial abdominal symptoms, but diagnosis remains challenging. The aim of this study was to identify characteristics of patients who had MALS compared with non-MALS patients among a cohort of patients diagnosed with celiac artery compression (CAC).

STUDY DESIGN

An IRB-approved retrospective chart review (2000 to 2021) of patients at our institution with a discharge diagnosis of CAC was performed. Medical record review for clinical symptoms and findings consistent with MALS was performed.

RESULTS

Two hundred ninety-three patients with a diagnosis of CAC were identified; 59.7% were women, and average age was 63.9 ± 20.2 years. Sixty-nine (23.5%) patients with CAC had MALS. There were no significant differences in sex or race between MALS and non-MALS patients, but MALS patients were younger (55.7 vs 68.1, p < 0.001). There was no significant difference in gastrointestinal comorbidities between the 2 groups. Patients with MALS were less likely to have diabetes (12.5% vs 26.9%), renal disease (4.6% vs 8.2%), hypertension (41.5% vs 70.3%), mesenteric atherosclerotic disease (14% vs 61.9%), and peripheral artery disease (15.0% vs 39.7%).

CONCLUSIONS

We demonstrate a novel observation that MALS patients tend to have fewer atherosclerotic characteristics than non-MALS patients with CAC. Patients in our study with MALS were more likely to be younger, women, and presenting with epigastric pain. MALS patients had a significantly lower incidence of diabetes, hypertension, renal disease, mesenteric artery disease, and peripheral arterial disease compared with the non-MALS group. An important clinically relevant feature of MALS patients may be their lack of atherosclerotic phenotype compared with non- MALS patients with CAC.

Utility of Hook Sign in the Diagnosis of Median Arcuate Ligament Syndrome

OBJECTIVE

Median arcuate ligament syndrome (MALS) is a clinical syndrome caused by compression of the celiac artery by the median arcuate ligament (MAL) that often manifests with non-specific abdominal pain. Identification of this syndrome is often dependent on imaging of compression and upward bending of the celiac artery by lateral CTA, the so-called "hook sign." The purpose of this study was to assess the relationship of radiologic characteristicss of the celiac artery to clinically relevant MALS.

DESIGN

Single-center retrospective study METHODS: An IRB-approved retrospective chart review from 2000-2021 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. CTA images were reviewed and the fold angle (FA) was measured. The presence of a hook sign (defined as a visual fold angle < 135 degrees) was recorded as well as stenosis (defined as >50% of luminal narrowing on imaging). Wilcoxon rank sum test and Chi-squared were utilized for comparative analysis. Logistic model was run to relate the presence of MALS with comorbidities and radiographic findings.

RESULTS

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 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.

CONCLUSIONS

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.

A Cross-sectional Survey on the Use of Tranexamic Acid in the Pre-hospital Setting

STUDY OBJECTIVE

Tranexamic Acid (TXA), an anti- fibrinolytic, has been used in military trauma cases and civilian Emergency Departments for several years. This study aims to evaluate protocols for the administration of TXA across Emergency Medical Services (EMS) regions in the United States.

METHODS

An anonymous survey was distributed by the National Association of Emergency Medical Technicians (NAEMT) to its members.

RESULTS

A total of 264 eligible responses were received. Respondents included paramedics (62.5%), emergency medical technicians (EMTs) (9%), critical care paramedics (11%), and other health care professionals (19%). The majority of protocols included criteria for blood pressure (67%), heart rate (53%), and age (66%). Notable variations included TXA dilution and indications for traumatic brain injury.

CONCLUSION

TXA has been widely implemented in EMS protocols since the CRASH (Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage) trials. However, there remains significant variations in indications and dose concentrations.