A Case of Median Arcuate Ligament Syndrome: Successful Angioplasty and Stenting

Abstract

Median arcuate ligament syndrome (celiac artery compression syndrome or Dunbar syndrome) is an uncommon vascular anomaly characterized by abdominal pain, nausea, and weight loss. It is caused by the compression of the celiac artery by the median arcuate ligament. Traditionally, this syndrome has been treated with laparoscopic division of the median arcuate ligament to relieve the extrinsic compression. The percutaneous approach has been used sparingly in the treatment of this condition. We report a patient with intractable nausea, vomiting, abdominal pain, and weight loss, who was diagnosed with this condition and underwent successful percutaneous angioplasty and stenting of the celiac artery, leading to complete resolution of symptoms acutely and up to 18 months post procedure.

Introduction

The median arcuate ligament (MAL) is a fibrous arch that unites the diaphragmatic crura on either side of the aortic hiatus. The MAL usually passes superior to the origin of the celiac trunk. In 10–24% of people, the ligament crosses anterior to the celiac artery and may cause compression of the celiac axis, thereby compromising blood flow and causing symptoms such as abdominal pain, nausea, and vomiting.¹ Identifying median arcuate ligament syndrome (MALS) is clinically important, as it can be surgically corrected by the resection of the MAL, with complete resolution of the symptoms with or without revascularization therapy. We report a case of successful percutaneous transluminal angioplasty (PTA) and stenting of the celiac artery in the setting of MALS.

Case Report

A 44-year-old female with a medical history of pernicious anemia, endometriosis, status post total abdominal hysterectomy, and bilateral salpingo-oophorectomy was admitted with complaints of 6-month abdominal pain, a 10–15 pound weight loss, and intractable nausea and vomiting for 2 days. She was initially managed with intravenous fluids (0.9% normal saline), nonsteroidal anti-inflammatory drugs (Ibuprofen) and anti-emetics (Promethazine). Pertinent history included smoking for 22 years. A physical exam, which included an abdominal and genital, was unremarkable. The initial evaluation for abdominal pain including abdominal plain radiographs, esophago-gastro-duodenoscopy, and colonoscopy were normal. A computed axial tomography (CAT) scan of the abdomen and pelvis and ultrasound of the hepatobiliary system did not reveal any obvious abnormalities. A duplex scan of the mesenteric arteries, including superior mesenteric artery (SMA), celiac artery (CA), inferior mesenteric artery (IMA), and abdominal aorta to rule out ischemia as a cause of her symptoms, was suggestive of a celiac artery stenosis (CAS) based on the peak systolic velocity (PSV) and end diastolic velocity (EDV) of 4.06 m/sec and 1.55m/sec, respectively. Subsequently, a selective angiography of the SMA and celiac trunk was done using the right common femoral approach. Findings included a normal SMA and a celiac trunk, which showed a 95% stenosis in a very angulated proximal segment 5–7 mm away from the ostium, which was unusual for an atherosclerotic lesion. The superior and inferior mesenteric arteries were free of atherosclerotic lesions. Collaterals were demonstrated from the SMA to the distal part of the celiac trunk. An attempt at angioplasty using a 7 Fr IMA guide catheter was unsuccessful, due to the severe angulation of the take-off of the celiac artery from the aorta. A decision was taken to re-attempt using the brachial approach. A selective angiography of the celiac trunk was performed via the right brachial artery with a 6 Fr system. During angiography this time, both inspiration and expiration films were compared, and it was found that CAS was more prominent during expiration, and a characteristic superior indentation was noted along the proximal celiac axis, which lead to the diagnosis of MALS. The celiac trunk was engaged with the aid of JR-4 (Cordis Corporation, Miami Lakes, Florida) catheter, and the lesion was crossed with 0.035 guidewire. PTA of the proximal celiac trunk was performed with a 6.0 x 20 mm balloon. As expected, there was no significant angiographic improvement, so a 7.0 x 17 mm Express stent (Boston Scientific, Natick, Massachusetts) was deployed at 6 atmospheres and postdilated at 12 atmospheres. Final angiographic results showed a minimal residual stenosis with no pressure gradient across the original lesion. The patient had complete resolution of her symptoms after the procedure and was discharged home two days later. On follow up, she continued to be pain free with no recurrent nausea or vomiting, and she gained about 15–20 lbs after the procedure because of her increased appetite. Subsequent follow-up visits have been event free, and an 18-month repeat duplex scan of the mesenteric vessels showed that the stent was patent with adequate antegrade hepatic and splenic arterial flow.

Discussion

MALS (also known as celiac artery compression syndrome or Dunbar syndrome) was first described in 1963 by Harjola.² The definition of the syndrome is based on a combination of both clinical and radiographic features, and MALS remains a diagnosis of exclusion. It usually affects young patients (20–40 years of age) and is more common in thin women. Symptoms are thought to arise from the extrinsic compression of the celiac axis by the median arcuate ligament, resulting in compromised blood flow. When the median arcuate ligament passes anterior to the celiac axis, a characteristic superior indentation is noted along the proximal celiac axis, usually about 5 mm from its origin at the abdominal aorta. Any compression caused by this indentation typically is less apparent during inspiration, when the celiac axis assumes a more caudal orientation as the lungs expand. During expiration, compression of the celiac axis typically increases, leading to a compromise in blood flow. Up to 13–50% of healthy patients may exhibit the angiographic feature of compression to a variable degree, especially during expiration.^3,4 Severe compression occurs in approximately 1% of patients, and more importantly, persists during inspiration, as seen in our patient.⁴ Isolated compression of the celiac axis during expiration may not be clinically significant. This is because of the extensive collateral circulation from the SMA. In addition, CAS is associated with ischemic gastroparesis (presenting as nausea and vomiting), as was the case with our patient.^5,6 Although the diagnosis of MALS is traditionally made by using catheter angiography, other modalities like vascular scan and computed tomography (CT) angiography have gained popularity recently.^7,8 Surgical treatment, which involves resection of the MAL coupled with removal of the celiac ganglion, is more likely to relieve symptoms in patients 40–60 years of age with postprandial pain, a greater than 20-lb weight loss, post-stenotic dilatation, and collateral vessel formation.^9,10,11 The ligamentous constriction of the celiac axis over a period of time may lead to intimal fibrosis, which may require vascular reconstruction. Revascularization might be considered in patients who had persistent compromised celiac flow despite relieving the extrinsic compression. A decision to revascularize might depend on intra-operative duplex assessment of the celiac blood flow, as described by Takach et al. The authors performed intra-operative duplex exam after surgical resection of the ligament, and if the velocities continued to be elevated, the patients underwent revascularization, which lead to improvement of their symptoms.¹² A percutaneous approach with stenting for extrinsic celiac artery compression has been reported previously but sparingly in the English literature. In a study by Silva et al, stenting was employed in four patients with extrinsic compression of the celiac artery with excellent immediate success. Only one of the four patients had a 3-year symptom-free follow up.¹³ The long-term outcome of the other three patients was not separately discussed. Our patient was in the right age group and had the classical symptomatology and angiographic features associated with MALS. Therapeutic options at that time included surgical resection of the ligament versus percutaneous revascularization. After having explained the various options for treatment and obtaining consent, a decision was taken to proceed with revascularization using the percutaneous technique. After a successful PTA/S, she experienced immediate and long-term resolution of symptoms. Outcomes of percutaneous revascularization of this condition remain to be studied, however, it seems that in selected patients, this may be an acceptable option. As for follow up, there are no specific guidelines on the frequency of duplex scans needed to assess stent patency for this condition. General recommendations after visceral artery stenting for atherosclerotic disease include a duplex scan at 1 week to 1 month, then at 6, 12, 18 and 24 months after stenting, and then yearly thereafter.¹⁴ Even though the stents may not be directly visualized in all cases, the flow parameters may reveal occlusions, restenosis, and stent displacement.

Conclusion

MALS should be included in the differential diagnosis of chronic abdominal pain, weight loss and vomiting in a young patient after having excluded common etiologies. Definitive radiographic and angiographic findings, along with clinical symptoms, are needed for the accurate diagnosis of MALS. Although laparoscopic resection of the ligament, with or without revascularization has been the preferred management strategy, angioplasty with stenting might be undertaken in the treatment of selected patients with this condition, while ensuring adequate long-term follow up to assess patency of the stent using either non-invasive (duplex) modalities. Our case demonstrates the success of angioplasty and stenting and the benefit of avoiding a decompression and revascularization surgery reflected in the fact that our patient had immediate clinical resolution of symptoms and continues to be symptom free at 18 months follow up with a documented patent stent.

Manuscript submitted July 17, 2008, provisional acceptance given September 8, 2008, accepted September 18, 2008.

Disclosure: The authors report no financial relationships or conflicts of interest regarding the content therein.

Correspondence: Mazen Abu-Fadel, MD, Section of Cardiovascular Medicine, 920 Stanton L. Young Blvd, WP 3010, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma. E-mail: mazen-abufadel@ouhsc.edu.