Identical anatomy, different symptoms: a comparative case study of median arcuate ligament syndrome in monozygotic twins.

Median arcuate ligament syndrome (MALS) is a rare clinical entity arising from the extrinsic compression of the coeliac axis by the median arcuate ligament. In this report, we detail a unique presentation involving monozygotic twins, both of whom demonstrated anatomical extrinsic compression of the coeliac axis by the median arcuate ligament. Intriguingly, only one twin manifested clinical symptoms consistent with MALS, despite comparable anatomical compression of the coeliac axis observed in both. This case highlights the potential interplay of a genetic or anatomical predisposition to coeliac axis compression and secondary, possibly environmental, factors that lead to the development of clinical symptoms. In this report, we explore various determinants potentially influencing symptomatology in MALS and advocate for the publication of similar case studies to further elucidate this rare condition.

Clinical Outcomes after Median Arcuate Ligament Release in Patients Responsive to Celiac Plexus Block.

PURPOSE: To determine if symptom relief with celiac plexus block (CPB) is associated with favorable clinical outcomes after median arcuate ligament release (MALR) surgery. MATERIALS AND METHODS: A retrospective review was performed from January 2000 to December 2021. Fifty-seven patients (42 women, 15 men; mean age, 43 years [range, 18-84 years]) with clinical and radiographic features suggestive of median arcuate ligament syndrome (MALS) underwent computed tomography (CT)-guided percutaneous CPB for suspected MALS. Clinical outcomes of CPB and MALR surgery were correlated. Adverse events were classified according to the Society of Interventional Radiology (SIR) guidelines. RESULTS: CT-guided percutaneous CPB was successfully performed in all 57 (100%) patients with suspected MALS. A cohort of 38 (67%) patients showed clinical improvement with CPB. A subset of 28 (74%) patients in this group subsequently underwent open MALR surgery; 27 (96%) responders to CPB showed favorable clinical outcomes with surgery. There was 1 (4%) CPB-related mild adverse event. There were no moderate, severe, or life-threatening adverse events. CONCLUSIONS: Patients who responded to CPB were selected to undergo surgery, and 96% of them improved after surgery.

First description of a histopathologic grading system and relationship to outcomes after robotic median arcuate ligament release with celiac ganglionectomy and lymphadenectomy.

BACKGROUND: Two dominating theories regarding median arcuate ligament syndrome include vascular and neurogenic etiologies from celiac artery and ganglion compression, respectively. Celiac ganglionectomy is not routine during surgery, and specimens are rarely excised; therefore, the extent of nerve involvement and histopathology are unknown. Our study aims to characterize histopathologic findings in median arcuate ligament syndrome, establish a histopathologic grading system, and correlate with clinical outcomes. METHODS: Robotic median arcuate ligament release, celiac ganglionectomy, and lymphadenectomy were performed with specimens excised and stained using hematoxylin & eosin, trichrome, and S100. Neurofibrosis, adiposity, and reactive changes were described, a grading scale was developed, and results were analyzed with clinical outcomes. RESULTS: Fifty-four patients were evaluated, of whom 36 met inclusion criteria (81% female, 34.9 [25.9-47.5] years, body mass index 23.5 [19.6-28.1] kg/m2). Histopathologic evaluation revealed fibrosis (hematoxylin & eosin and trichrome median score 1.5 [0-2.5]), reactive lymphadenopathy (89%), intraparenchymal nerves (31%), and lipogranulomas (31%). Greater fibrosis was associated with a lack of preoperative celiac plexus block relief (100% vs. 30%, P = .044) and lower postoperative celiac artery velocities (198 vs 323 cm/s, P = .02). Intraparenchymal nerves were associated with greater decreases in pre to postoperative velocities (161 vs 84 cm/s, P = .037). Symptoms improved in 28 patients (78%). CONCLUSION: We developed the first histopathologic grading system and identified unique findings of intraparenchymal nerves and lipogranulomas. Histopathologic abnormalities were associated with objective improvement and symptomatic relief postoperatively. These findings support nerve compression and inflammation as predominant contributors to median arcuate ligament syndrome pain, celiac ganglia resection to treat symptoms, and continued histopathologic analysis to better elucidate median arcuate ligament syndrome etiology.

[Diagnosis and treatment of Dunbar syndrome]. / Diagnostik und Therapie des Dunbar-Syndroms.

The rare Dunbar syndrome or medial arcuate ligament syndrome (MALS) is defined as compression of the celiac trunk and/or ganglion by the medial arcuate ligament. It is often diagnosed after patients have suffered for a long time and is characterized by intermittent food-related pain, nausea, and unexplained weight loss. After exclusion of other causes of the above symptoms by gastroscopy, colonoscopy, CT, or MRI, the gold standard for diagnosis is dynamic color-coded duplex sonography, which may be supplemented by CT or MR angiography. The treatment of choice is a laparoscopic division of the arcuate ligament at the celiac trunk, although percutaneous transluminal angioplasty (PTA) with stent implantation may be performed in cases of postoperative persistence of symptoms or recurrent stenosis. Since symptoms persist postoperatively in up to 50% of cases, strict indication and complete diagnosis in designated centers are of great importance for successful treatment.

Pancreaticoduodenal Artery Aneurysm Complicated by Median Arcuate Ligament Syndrome.

PURPOSE: To highlight median arcuate ligament syndrome as a potential cause for celiac artery stenosis and pancreaticoduodenal artery aneurysm, and describe treatment options in this setting. CASE REPORT: A 63-year-old male presented with a pancreaticoduodenal artery aneurysm and concomitant celiac artery stenosis that was treated with celiac artery stenting and aneurysm coiling. He subsequently developed stent fracture and celiac artery occlusion secondary to previously unrecognized median arcuate ligament syndrome causing reperfusion of the aneurysm. This was treated with open median arcuate ligament release and aorta to common hepatic artery bypass with good clinical result and stable 20-month surveillance imaging. CONCLUSION: It is critical to recognize median arcuate ligament syndrome as a cause of celiac artery stenosis in the setting of pancreaticoduodenal artery aneurysm given the high risk of failure of endovascular stenting. Open aorto-hepatic artery bypass and endovascular aneurysm coiling should be the preferred approach in these patients.

Celiac trunk thrombosis in a patient with antiphospholipid syndrome induced by median arcuate ligament compression: a case presentation and literature review.

Median arcuate ligament syndrome (MALS) is a rare disorder caused by the compression of the celiac axis by the fibrous structure of the diaphragm called the median arcuate ligament. Patients with MALS are usually undiagnosed unless characteristic symptoms such as nausea and vomiting, postprandial pain, and weight loss are presented. We report a case of a 29-year-old patient diagnosed with MALS and secondary antiphospholipid syndrome (APS) that developed celiac trunk, common hepatic artery and splenic artery thrombosis. There is not enough information on MALS as a trigger of thrombosis in predisposed patients such as those with APS. However, the case gives rise to suspicion and highlights the diagnostic processes, especially for patients with APS presenting postprandial abdominal pain and weight loss. This review likewise aims at the importance of Doppler ultrasonography as a screening tool and computer tomography (CT) or magnetic resonance (MR) both in the angiography variant, especially to diagnose confirmation and underlying treatment options.

Prognostic factors for the long term outcome after surgical celiac artery decompression in MALS.

BACKGROUND: The median arcuate ligament syndrome (MALS) is a rare disease caused by compression of the celiac artery (ORPHA: 293208). Surgical treatment of MALS aims to restore normal celiac blood flow by laparoscopic celiac artery decompression. However, surgical success rates vary widely between patients, therefore adequate selection of patients is essential to improve surgical outcome. Symptoms of MALS might also overlap with other chronic multi-system disorders such as mast cell activation syndrome (MCAS). So far, no clinical or radiological parameter was found to be predictive of the postoperative outcome. We, therefore, aim to study preclinical parameters in one of the largest MALS cohorts with the focus to identify patients that would benefit from surgical MAL release. RESULTS: By analyzing 20 MALS patients that underwent surgical celiac artery decompression, we found 60% of patients (12/20) had a postoperative relief of their symptoms and a simultaneous decrease of analgetic use. No demographic, radiologic or operative parameter was able to predict postoperative symptom relief. However, mast cell activation syndrome correlated significantly (p = 0.04) with persistent symptoms after the operation. CONCLUSIONS: Overall, laparoscopic MAL release can provide immediate symptomatic relief. Despite the missing predictive value of demographic and imaging data, our data show a correlation between persistent symptoms and a co-existing mast cell activation syndrome. This suggests that MCAS symptoms might be interpreted as MALS symptoms in the presence of celiac artery stenosis and therefore surgical treatment should be evaluated carefully. Overall, the selection of patients who are most likely to respond to surgical MAL release may best be accomplished by an interdisciplinary team of gastroenterologists, radiologists and surgeons.

Obstructive jaundice as a rare complication of multiple pancreaticoduodenal artery aneurysms due to median arcuate ligament syndrome: a case report and review of the literature.

BACKGROUND: Obstructive jaundice has various causes, and one of the rarest is pancreaticoduodenal artery aneurysm (PDAA), which is often associated with celiac axis stenosis caused by median arcuate ligament syndrome (MALS). CASE PRESENTATION: The patient was a 77-year-old Azeri woman who presented with progressive jaundice, vague abdominal pain, and abdominal distension from 6 months ago. The intra- and extrahepatic bile ducts were dilated, the liver's margin was slightly irregular, and the echogenicity of the liver was mildly heterogeneous in the initial ultrasound exam. A huge cystic mass with peripheral calcification and compressive effect on the common bile duct (CBD) was also seen near the pancreatic head, which was connected to the superior mesenteric artery (SMA) and had internal turbulent blood flow on color Doppler ultrasound. According to the computed tomography angiography (CTA) findings, the huge mass of the pancreatic head was diagnosed as a true aneurysm of the pancreaticoduodenal artery caused by MALS. Two similar smaller aneurysms were also present at the huge aneurysm's superior margin. Due to impending rupture signs in the huge aneurysm, the severe compression effect of this aneurysm on CBD, and the patient's family will surgery was chosen for the patient to resect the aneurysms, but unfortunately, the patient died on the first day after the operation due to hemorrhagic shock. CONCLUSION: In unexpected obstructive jaundice due to a mass with vascular origin in the head of the pancreas, PDAA should be considered, and celiac trunk should be evaluated because the main reason for PDAA is celiac trunk stenosis or occlusion by atherosclerosis or MALS. The treatment method chosen (including transarterial embolization, open surgery, or combined method) depends on the patient's clinical status and radiological findings, but transarterial embolization would be safer and should be used as a first-line method.

Transarterial embolization for ruptured pancreaticoduodenal artery aneurysm due to segmental arterial mediolysis combined with median arcuate ligament syndrome: a case report.

A 75-year-old female with a history of Parkinson's disease treatment and hypertension presented at the emergency section with sudden onset of right abdominal pain. Contrast-enhanced computed tomography revealed beaded irregular stenosis and dilation of the superior mesenteric artery (SMA) and an aneurysm in the branch of the pancreaticoduodenal artery (PDA) that communicates with the common hepatic artery and SMA. Additionally, a hematoma had formed in the retroperitoneal space, and extravasation of contrast medium from the pancreaticoduodenal artery aneurysm (PDAA) into the hematoma was observed. The celiac artery (CA) was compressed by the median arcuate ligament; stenosis of the CA at its origin and dilation on the distal side were observed. Based on the imaging findings, it was diagnosed that PDAA was ruptured, SMA developed segmental arterial mediolysis (SAM), and CA developed median arcuate ligament syndrome (MALS). The ruptured PDAA was thought to be caused by SAM combined with MALS. Transcatheter arterial embolization (TAE) was performed for the ruptured PDAA. To the best of our knowledge, there have been no reports of TAE for a ruptured PDAA caused by SAM and MALS. After TAE, the PDAA did not re-rupture.

Pancreaticoduodenectomy combined gastroduodenal collateral reconstruction and preservation due to median arcuate ligament syndrome: technical notes with two surgical cases report (with video).

INTRODUCTION: Pancreaticoduodenectomy in patients with CA stenosis due to median arcuate ligament often required carefully collateral pathways management to avoid hepatic ischemic complications. CASES PRESENTATION: Case 1: A 63-year-old man was referred to our department because of jaundice with distal common bile duct tumor. Pancreaticoduodenectomy with left posterior SMA first approach and circumferential lymphadenectomy was performed. Case 2: A 48-year-old man was referred to our department because of right-upper-quadrant abdominal pain with Vater tumor. Laparoscopic pancreaticoduodenectomy with left posterior SMA first approach and circumferential lymphadenectomy was performed. Postoperatively, in all two cases, three-dimensional reconstruction images showed developed collateral pathways around the pancreatic head, and the CA was stenosis in 75% and 70% due to MAL, respectively. Intraoperatively, in all two cases, we confirmed poor blood flow in the common hepatic artery (CHA) by palpation and observation. So that in the first case, we have decided to proceed a no-touch technique of GDA segmental resection en bloc with the tumor and reconstructed with an end-to-end GDA anastomosis; in the second cases, we have decided to proceed gastroduodenal collateral preservation. When preserving these collateral pathways, we confirmed that the PHA flow remained pulsatile as an indicator that the blood flow was adequate. CONCLUSION: Celiac axis stenosis was a rare but difficult-to-managed condition associated with pancreaticoduodenectomy. Collateral pathways management depends on variety of collateral pathways.

Trauma-Induced Median Arcuate Ligament Syndrome is an Under-Recognized Source of Chronic Abdominal Pain.

Median arcuate ligament syndrome (MALS) can be a debilitating condition resulting in epigastric pain, nausea, difficulty eating due to postprandial pain, weight loss, and malnutrition in otherwise healthy individuals. The pain is caused by the compression of the celiac artery and neural ganglia by the median arcuate ligament as it attaches from the spine to the diaphragm. Diagnostic imaging, either duplex or angiography, can show the abnormality however, vague symptoms can lead to a missed diagnosis. While MALS is a known anatomical variation in the population, to our knowledge, has not been identified to be caused by trauma. Here, we present 4 patients who developed MALS following abdominal or spinal trauma whom all required surgery to alleviate lifestyle-limiting pain.

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

BACKGROUND: 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. METHODS: 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. 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 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. 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.

Outcomes of Median Arcuate Ligament Release: A Single Institution Retrospective Review.

BACKGROUND: Median arcuate ligament syndrome (MALS) is an uncommon diagnosis that is often associated with variable clinical presentation and inconsistent response to treatment. Due to the nature of MALS, the optimal treatment modality and predictors of outcomes remain unclear. METHODS: A retrospective review was performed of all median arcuate ligament release (MALR) procedures at a single academic institution between 2000 and 2020. Variables examined included patient demographics, symptom characteristics, operative technique (open, robotic, laparoscopic), patient symptoms before release, symptom relief within 1 year, and recurrence of symptoms between release and last clinical follow-up. RESULTS: During the study period, 47 patients (75% female, mean age 42.1 years) underwent MALR with 19 (36%) robotic, 18 (34%) open, 14 (26%) laparoscopic, and 2 (4%) laparoscopic converted to open procedures. Abdominal pain, weight loss, and nausea and vomiting were the most common symptoms. Postoperatively, 19 (40%) had complete symptom relief within 1 year, 18 (38%) had partial relief, and 10 (21%) had no symptom improvement. 6 were excluded due to loss of follow-up. Laparoscopic and open procedures had the highest rate of complete symptom relief by year 1 with 7 (58%) and 8 (50%) respectively. Twenty-one (57%) patients had recurrence with the greatest rate of recurrence seen among laparoscopic (80%), compared to robotic (57%) and open (38%). Patients reporting a weight loss of 20 pounds or more before surgery were more likely to have partial or complete symptom relief after 1 year compared to those reporting less than 20-pound weight loss (92% vs. 64%). Furthermore, 84% of patients younger than 60 years old reported partial or complete symptom relief compared to only 56% of those older than 60. CONCLUSIONS: MALS continues to be a rare disorder with widely variable surgical outcomes, requiring further study. While our patients presented with several gastrointestinal symptoms, the most common was postprandial pain. Our center employed laparoscopic, open, and robotic operative techniques with varying success rates, in terms of symptom relief and recurrence. Consistent with current literature, our study found greater surgical success among patients younger than 60 years regardless of operative technique. This suggests the need for better predictors to determine which patients are the most likely to have complete or prolonged remission of symptoms following MALR.

Median arcuate ligament syndrome: a rare cause of abdominal pain.

MALS, also called celiac artery compression syndrome, celiac axis syndrome, or Dunbar syndrome, is a rare entity caused by progressive stenosis of the celiac trunk secondary to extrinsic compression of the fibers of the median arcuate ligament. The prevalence is unknown, but it is estimated that it is a casual finding in up to a third of autopsies2,3, being more prevalent in women between 30 and 50 years of age4. Symptoms and signs include postprandial abdominal pain, exercise-induced pain, nausea, vomiting, and weight loss3. However, most cases are asymptomatic. The case that we present was a 56-year-old man, with a history of dyslipidemia, type 2 diabetes mellitus, and chronic ischemic heart disease. He was a former smoker. He reported a history of recurrent abdominal pain, especially postprandial.

Minimally Invasive Surgery for Median Arcuate Ligament Syndrome and Celiac Artery Stenosis.

Median arcuate ligament syndrome (MALS) is a pathology commonly reported in educational literature, although in reality it is scarcely seen. Herein, we present the case of a 48-year-old female patient who presented with nausea, vomiting, and unintentional weight loss. After thorough work up of her symptoms through a variety of different modalities, MALS was confirmed and she underwent surgical release via a minimally invasive approach. The authors of this article feel that this case is important to present due to paucity of reported cases in the literature. In addition, this patient was exceptionally unique to report as we selected to perform a slight adaptation of a minimally invasive approach, while there are multiple different treatment techniques and management plans that have previously been described in a variety of different literatures and require further discussion.

Factors associated with successful median arcuate ligament release in an international, multi-institutional cohort.

OBJECTIVE: Prior research on median arcuate ligament syndrome has been limited to institutional case series, making the optimal approach to median arcuate ligament release (MALR) and resulting outcomes unclear. In the present study, we compared the outcomes of different approaches to MALR and determined the predictors of long-term treatment failure. METHODS: The Vascular Low Frequency Disease Consortium is an international, multi-institutional research consortium. Data on open, laparoscopic, and robotic MALR performed from 2000 to 2020 were gathered. The primary outcome was treatment failure, defined as no improvement in median arcuate ligament syndrome symptoms after MALR or symptom recurrence between MALR and the last clinical follow-up. RESULTS: For 516 patients treated at 24 institutions, open, laparoscopic, and robotic MALR had been performed in 227 (44.0%), 235 (45.5%), and 54 (10.5%) patients, respectively. Perioperative complications (ileus, cardiac, and wound complications; readmissions; unplanned procedures) occurred in 19.2% (open, 30.0%; laparoscopic, 8.9%; robotic, 18.5%; P < .001). The median follow-up was 1.59 years (interquartile range, 0.38-4.35 years). For the 488 patients with follow-up data available, 287 (58.8%) had had full relief, 119 (24.4%) had had partial relief, and 82 (16.8%) had derived no benefit from MALR. The 1- and 3-year freedom from treatment failure for the overall cohort was 63.8% (95% confidence interval [CI], 59.0%-68.3%) and 51.9% (95% CI, 46.1%-57.3%), respectively. The factors associated with an increased hazard of treatment failure on multivariable analysis included robotic MALR (hazard ratio [HR], 1.73; 95% CI, 1.16-2.59; P = .007), a history of gastroparesis (HR, 1.83; 95% CI, 1.09-3.09; P = .023), abdominal cancer (HR, 10.3; 95% CI, 3.06-34.6; P < .001), dysphagia and/or odynophagia (HR, 2.44; 95% CI, 1.27-4.69; P = .008), no relief from a celiac plexus block (HR, 2.18; 95% CI, 1.00-4.72; P = .049), and an increasing number of preoperative pain locations (HR, 1.12 per location; 95% CI, 1.00-1.25; P = .042). The factors associated with a lower hazard included increasing age (HR, 0.99 per increasing year; 95% CI, 0.98-1.0; P = .012) and an increasing number of preoperative diagnostic gastrointestinal studies (HR, 0.84 per study; 95% CI, 0.74-0.96; P = .012) Open and laparoscopic MALR resulted in similar long-term freedom from treatment failure. No radiographic parameters were associated with differences in treatment failure. CONCLUSIONS: No difference was found in long-term failure after open vs laparoscopic MALR; however, open release was associated with higher perioperative morbidity. These results support the use of a preoperative celiac plexus block to aid in patient selection. Operative candidates for MALR should be counseled regarding the factors associated with treatment failure and the relatively high overall rate of treatment failure.

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.