Median Arcuate Ligament Syndrome: Treatment

Number: 1092

Table Of Contents

Policy
Applicable CPT / HCPCS / ICD-10 Codes
Background
References

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Policy

Scope of Policy

This Clinical Policy Bulletin addresses the median arcuate ligament syndrome (MALS) treatment. 

1. Medical Necessity

   Aetna considers the following procedures as medically necessary for the treatment of median arcuate ligament syndrome (MALS), also known as celiac artery compression syndrome (CACS), when the following criteria are met:

   1. Open or laparoscopic (standard or robotic-assisted) surgical decompression of the celiac artery (median arcuate ligament release) with or without celiac plexus neurolysis or celiac ganglionectomy when all of the following criteria are met: (Note: Robotic assistance is considered integral to the procedure and not separately reimbursed.)

      1. Member has symptomatic postprandial abdominal pain; and
      2. Duplex ultrasound is suggestive of celiac artery compression (i.e., increased flow velocities: greater than 200 cm/second for celiac artery and/or greater than 275 cm/second for superior mesenteric artery); and
      3. Cross-sectional abdominal imaging (computed tomographic [CT] or magnetic resonance [MR] imaging) is suggestive of celiac artery compression (e.g., celiac artery stenosis with or without post-stenotic dilation or splanchnic artery aneurysm); and
      4. Diagnosis has been confirmed with computed tomography angiography (CTA) or magnetic resonance angiography (MRA) imaging (i.e., focal narrowing of the proximal celiac artery forming a hooked or J-shaped appearance); and
      5. Member has a documented preoperative psychiatric or behavioral health assessment; 

   2. Percutaneous revascularization (e.g., celiac artery angioplasty/stenting) or surgical revascularization (i.e., interposition or bypass grafting) when all of the following criteria are met:

      1. Member is post-surgical decompression of the celiac artery (median arcuate ligament release); and
      2. Member has refractory postprandial abdominal pain; and
      3. Other causes have been excluded (e.g., mast cell activation syndrome, functional gastrointestinal (GI) disorders); and
         
      4. Persistent stenosis or residual compression is confirmed on imaging, define as:
         
         
         1. Duplex ultrasound: Peak systolic velocity greater than 200 cm/second in the celiac artery during expiration; or 
         2. CTA or MRA: Focal narrowing of the proximal celiac artery forming a hooked or J-shaped appearance and greater than 30% residual stenosis of the celiac artery post-decompression;

   3. Celiac plexus nerve block for either of the following indications:

      1. As an adjunct to aid in diagnosis of MALS or establish surgical candidacy and when imaging studies (i.e., Duplex ultrasound, CT or MRI, CTA or MRA) have been performed; or
      2. Treatment of postprandial abdominal pain and has documented diagnosis of MALS.

2. Experimental and Investigational

   Aetna considers gastric tonometry experimental, investigational, or unproven for diagnosing MALS because the effectiveness of this approach has not been established.

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Table:

CPT Codes / HCPCS Codes / ICD-10 Codes

Code	Code Description
CPT codes covered if selection criteria are met:
Open or laparoscopic (standard or robotic-assisted) surgical decompression of the celiac artery (median arcuate ligament release) –no specific code
35631	Bypass graft, with other than vein; aortoceliac, aortomesenteric, aortorenal [Surgical revascularization (i.e., interposition or bypass grafting)]
35632	Bypass graft, with other than vein; ilio-celiac [Surgical revascularization (i.e., interposition or bypass grafting)]
37236	Transcatheter placement of an intravascular stent(s) (except lower extremity artery(s) for occlusive disease, cervical carotid, extracranial vertebral or intrathoracic carotid, intracranial, or coronary), open or percutaneous, including radiological supervision and interpretation and including all angioplasty within the same vessel, when performed; initial artery [Percutaneous revascularization (celiac artery angioplasty/stenting]
37237	Transcatheter placement of an intravascular stent(s) (except lower extremity artery(s) for occlusive disease, cervical carotid, extracranial vertebral or intrathoracic carotid, intracranial, or coronary), open or percutaneous, including radiological supervision and interpretation and including all angioplasty within the same vessel, when performed; each additional artery (List separately in addition to code for primary procedure) [Percutaneous revascularization (celiac artery angioplasty/stenting]
64530	Injection, anesthetic agent; celiac plexus, with or without radiologic monitoring
CPT codes not covered for indications listed in the CPB:
Gastric tonometry –no specific code
Other CPT codes related to the CPB:
Celiac ganglionectomy – no specific code
64680	Destruction by neurolytic agent, with or without radiologic monitoring; celiac plexus
74150	Computed tomography, abdomen; without contrast material
74160	with contrast material(s)
74170	without contrast material, followed by contrast material(s) and further sections
74174	Computed tomographic angiography, abdomen and pelvis, with contrast material(s), including noncontrast images, if performed, and image postprocessing
74175	Computed tomographic angiography, abdomen, with contrast material(s), including noncontrast images, if performed, and image postprocessing
74176	Computed tomography, abdomen and pelvis; without contrast material
74177	with contrast material(s)
74178	without contrast material in one or both body regions, followed by contrast material(s) and further sections in one or both body regions
74181	Magnetic resonance (eg, proton) imaging, abdomen; without contrast material(s)
74182	with contrast material(s)
74183	without contrast material(s), followed by with contrast material(s) and further sequences
74185	Magnetic resonance angiography, abdomen, with or without contrast material(s)
93975	Duplex scan of arterial inflow and venous outflow of abdominal, pelvic, scrotal contents and/or retroperitoneal organs; complete study
93976	limited study
ICD-10 codes not covered for indications listed in the CPB (not all-inclusive):
D89.40 - D89.49	Mast cell activation syndrome and related disorders
K59.0 - K59.9	Other functional intestinal disorders
K30	Functional dyspepsia

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Background

Median Arcuate Ligament Syndrome (MALS), also known as celiac artery compression syndrome or Dunbar syndrome, is an uncommon vascular compression disorder caused by the median arcuate ligament exerting pressure on the celiac artery and adjacent celiac plexus. Chronic compression can lead to arterial hyperplastic intimal changes, potentially resulting in partial or complete arterial occlusion (stenosis), reduced blood flow, and post-stenotic dilation (Goodall et al., 2020). Although the exact incidence of MALS is unknown, it is estimated to occur in approximately 2 cases per 100,000 patients with chronic, diffuse, and intermittent nonspecific abdominal pain. MALS is more prevalent in females than males (4:1) and typically affects individuals aged 30 to 50 years, particularly those with a thin body habitus (Robson et al., 2025). The clinical presentation often mimics other causes of abdominal pain, complicating diagnosis.

When evaluating patients with vascular-related symptoms, healthcare providers may consider various conditions, including peripheral vascular disease (PVD). However, MALS is generally seen in younger individuals, especially women, and is characterized by postprandial abdominal pain, which can help differentiate it from other vascular issues. The absence of leg pain or claudication, along with gastrointestinal symptoms, may further suggest MALS. Imaging studies, such as Doppler ultrasound and computed tomography angiography (CTA), are essential for confirming the diagnosis by revealing celiac artery compression. Key imaging parameters include a peak systolic velocity exceeding 200 cm/s in the celiac artery on duplex ultrasound, indicating 70% or greater stenosis, and the presence of a characteristic hooked or "J" appearance of the celiac artery on CTA, along with post-stenotic dilation. Magnetic resonance angiography (MRA) can also reveal similar features without radiation exposure. Celiac plexus blocks have shown promise in providing symptom relief and may indicate candidates for surgical intervention, although the presence of celiac artery compression does not always correlate with symptom severity. A multifactorial approach that combines clinical evaluation, imaging findings, and patient history is crucial for accurate diagnosis and management of MALS, underscoring the importance of awareness among healthcare professionals to facilitate timely diagnosis and treatment.

Surgical Decompression

Sun et al. (2019) emphasize that the treatment for median arcuate ligament syndrome (MALS) aims to relieve compression of the celiac trunk. This is typically achieved through the separation of ligament fibers and surrounding tissues at the celiac trunk's origin, which can be performed via laparotomy or laparoscopic surgery. The prognosis for patients is generally favorable, with a cure rate of approximately 80%. However, the appropriate treatment remains debated due to varying definitions of MALS and differing criteria for patient selection. Since the compression is physical rather than caused by intravascular lesions like atherosclerosis, methods such as percutaneous balloon dilation or stenting are not applicable. In some cases, the celiac plexus may be removed to address ischemia associated with the compression. Laparoscopic surgery is preferred in many hospitals due to its potential to reduce surgical trauma and hospitalization, and it can be enhanced with robotic assistance for improved precision and visualization. A review of the literature indicated that 85% of patients experienced immediate symptom relief post-surgery, with low rates of recurrence and no procedure-related deaths. Factors influencing better surgical outcomes include the presence of postprandial abdominal pain, age, significant weight loss, and the absence of mental health or substance abuse issues. The authors highlight the need for further clinical experience to establish optimal treatment strategies, particularly given the neurogenic aspects of MALS, and stress the importance of timely intervention to prevent complications such as aneurysm rupture.

Goals in management of MALS are to relieve compression of the celiac artery trunk, restore adequate blood flow through the vessel, and neurolysis to alleviate chronic pain. Definitive treatment of MALS is by surgical procedure to release median arcuate ligament compression of the celiac trunk and axis. The surgical approach may be performed through open surgical or laparoscopic decompression. However, laparoscopic approach for decompression of the celiac artery has become increasingly accepted as standard surgical management of MALS. Endovascular stenting of the celiac artery is not primarily recommended for patients with MALS who have not had adequate celiac artery release (Robson et al., 2025).

In a prospective cohort study, Kazmi et al. (2022) evaluated 52 consecutive patients diagnosed with MALS who underwent transperitoneal laparoscopic decompression. The primary endpoint was symptom relief, assessed through follow-up at 3, 6, and 12 months, and annually thereafter. At 3 to 6 months, 90% of patients experienced symptom relief, with 67% reporting complete and 23% partial improvement. Postoperative imaging showed a significant reduction in peak systolic velocity (PSV) of the celiac artery (p < 0.001), indicating improved blood flow. The authors concluded that laparoscopic decompression is an effective treatment for MALS, emphasizing careful patient selection based on imaging and symptom correlation. Limitations of the study include single-center design, relatively small sample size, and lack of a control group, which may affect generalizability.

In a retrospective study, Shin et al. (2022) compared robotic (RMALR) and laparoscopic (LMALR) median arcuate ligament release in 50 patients (26 RMALR, 24 LMALR) treated by a single surgeon at a quaternary academic center between March 2018 and August 2019. The primary endpoint was the reduction in celiac trunk expiratory peak systolic velocities (PSVs), which significantly improved in both groups (LMALR p = 0.0011; RMALR p = 0.0022; no significant difference between groups, p = 0.7772). Secondary outcomes showed that RMALR had longer operative times (134 vs. 86 minutes, p < 0.0001), but both groups had a 1-day hospital stay and no open conversions. RMALR patients reported greater relief of postprandial pain (p < 0.0001) and chronic nausea (p = 0.0002), while LMALR patients had better chronic abdominal pain relief. RMALR also involved more junior first assistants (p = 0.0001) and fewer second assistants (p = 0.0381). The study concludes that both approaches are safe and effective, though limited by its retrospective design, small sample size, and single-surgeon experience.

Romero-Velez et al. (2023) conducted a retrospective, cross-sectional study using data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP), analyzing 763 adult patients (578 were classified as open [76%] and 185 as laparoscopic [24%]) who underwent MAL release between 2010 and 2020. The primary endpoint was the assessment of postoperative outcomes, including complication rates and length of hospital stay. The study found an increase adoption of the laparoscopic approach, with 22% of the cases employing this technique at the end of the study period, compared to 7% at the beginning of the study period. The open group had a higher prevalence of hypertension (26% vs 18%, p = 0.04) and bleeding disorders (5% vs 2%, p 0.03). Laparoscopic approach had a shorter length of stay (2.3 days vs 5.2 days, p < 0.0001), lower major complication rates (0.5% vs 4.0%, p = 0.02) and lower reoperation rates (0% vs 2.6%, p = 0.03). Overall mortality was 0.1%. The authors report that these outcomes supported the safety and feasibility of MAL release, particularly when performed laparoscopically. The authors recommended further standardization of surgical techniques and patient selection criteria. Limitations include the lack of long-term follow-up data (longer than 30-day outcomes), absence of symptom resolution metrics, and potential coding inaccuracies inherent in large database studies.

In an UpToDate review on "Median arcuate ligament syndrome", Scovell and Hamdan (2025) state that treatment should be reserved for patients who present with both clinical symptoms and confirmed vascular compression. For individuals with incidental findings of celiac artery compression but no abdominal symptoms, no further evaluation is necessary — provided the superior mesenteric artery is patent and collateral flow is evident. These patients are typically counseled about potential symptoms and advised to follow up only if postprandial abdominal pain develops. For symptomatic patients with confirmed celiac artery compression on inspiratory and expiratory imaging, the recommended treatment is surgical decompression of the celiac artery, often accompanied by celiac plexus neurolysis to alleviate pain. This can be performed via open surgery or minimally invasive techniques, with laparoscopic or robotic-assisted approaches now preferred due to better visualization and more thorough nerve and tissue release. Before surgery, a comprehensive medical and psychological evaluation is essential to ensure appropriate patient selection. Postoperative or intraoperative assessment of celiac artery flow is typically done using duplex ultrasound or arteriography, with laparoscopic ultrasound probes being the most practical during minimally invasive procedures. 

The authors state that many surgeons perform concurrent neurolysis or celiac ganglionectomy to address potential neuropathic components of the condition. They emphasize that aggressive resection of the median arcuate ligament and associated nerve fibers may prevent reformation of the ligament. Various surgical approaches, including open, laparoscopic, and robotic-assisted techniques, can be utilized for decompression, although outcomes are primarily derived from small institutional reviews due to the syndrome's rarity, which limits the ability to determine the best treatment approach with certainty. The authors recommend median arcuate ligament release as the primary surgical intervention, often accompanied by ganglionectomy.

A psychiatric or behavioral health assessment prior to celiac artery decompression for MALS is important due to the significant psychological impact of chronic pain, which can lead to anxiety, depression, and other mood disorders. Addressing mental health can improve surgical outcomes, as untreated psychological conditions may result in poorer recovery rates and lower satisfaction with results. Additionally, such assessments ensure informed consent by helping patients understand the risks and benefits of surgery, while also identifying coping mechanisms and support systems for postoperative care. This multidisciplinary approach is crucial for differentiating between organic and psychosomatic issues, ultimately guiding a more comprehensive treatment plan that addresses both physical and psychological health (Scovell and Hamdan, 2025; Skelly and Mak, 2024; Zbinden et al., 2024).

Scovell and Hamdan (2025) mention that intraoperative vascular assessment for MALS involves confirming the completeness of celiac artery release through visual inspection or direct evaluation of celiac flow to determine if further decompression or additional treatments are necessary. Techniques such as arteriography or duplex ultrasound can be employed, with intraoperative ultrasound using a laparoscopic probe being the most practical option in minimally invasive procedures. Ultrasound can confirm adequate decompression by directly visualizing the vessel and showing that celiac artery velocities have returned to normal levels. In one study utilizing laparoscopic ultrasound, 14 out of 15 patients (93%) reported subjective symptom improvement at a mean follow-up of 44.2 months. However, symptom resolution has been observed both with and without the use of intraoperative ultrasound. Another alternative is intraoperative aortography, which involves obtaining anteroposterior and lateral views before and after decompression, especially in a hybrid operating room setting. This arteriography can be facilitated by positioning an aortic catheter prior to the decompression procedure.

The authors highlight the advantages of minimally invasive techniques for the treatment of MALS, such as reduced postoperative morbidity and shorter recovery times, while also acknowledging potential challenges, including difficulty controlling hemorrhage and the risk of incomplete decompression. They conclude that while celiac artery decompression generally provides symptom relief, the need for further interventions, such as angioplasty or open revascularization, may arise in cases of persistent stenosis or recurrent symptoms. Overall, the limitations of small patient populations and the variability in symptoms and treatment regimens underscore the necessity for further research to optimize the management of MALS.

Percutaneous and Surgical Revascularization

Terlouw et al. (2020) discuss the ongoing debate regarding the revascularization of patients with occlusive disease affecting both the celiac artery (CA) and the superior mesenteric artery (SMA). Current evidence comparing partial and complete revascularization is primarily derived from low-quality cohort studies, which indicate high rates of clinical success following revascularization of the SMA alone. Although the sample sizes in comparative studies are too small to demonstrate a significant difference in five-year survival rates, there is a noted trend favoring complete revascularization. Complete revascularization is linked to better outcomes in terms of freedom from symptom recurrence at three, five, and ten years post-procedure. While the expert panel advises caution in interpreting the existing evidence, they concur that complete revascularization appears to offer long-term benefits. Therefore, when feasible, revascularization of both the CA and SMA should be considered. In cases of single-vessel revascularization, the SMA is prioritized as the target artery, followed by the CA.

Saiga et al. (2022) reported on the case of a 61-year-old man who presented with retro-peritoneal hemorrhage caused by an aneurysm rupture of the pancreaticoduodenal arcade (PDA), and acute celiac artery dissection distal to celiac axis stenosis. Owing to the gradual growth of the false lumen, these investigators planned to deploy a stent to the celiac artery dissection and embolize the PDA aneurysm. Before stent placement, these researchers evaluated the acute celiac artery dissection distal to the stenosis using four-dimensional (4D) computed tomography angiography (CTA) via the expiration/inspiration/expiration cycle. They diagnosed median arcuate ligament syndrome considering that the celiac axis showed a hooked narrowing at end-expiration, and the compression decreased at end-inspiration. Furthermore, the true lumen distal to the stretched axis dilated in the inspiration phase; thus, they could advance a catheter into the true lumen during inspiration and successfully deployed a stent. Subsequently, laparoscopic median arcuate ligament release was carried out following the stent deployment. A post-operative CT scan showed good patency in the stent, with disappearance of the blood filling the false lumen and with reduced celiac axis stenosis.

The ACR Appropriateness Criteria for the Radiologic Management of Mesenteric Ischemia 2022 Update discusses the role of percutaneous transluminal angioplasty with stent placement in the treatment of median arcuate ligament syndrome (MALS). The literature suggests that endovascular intervention alone may be less effective than when combined with surgical release of the median arcuate ligament, due to ongoing extrinsic compression and chronic changes to the vessel wall from repeated stress. After surgical release, endovascular stenting of the celiac artery is indicated if there is residual stenosis greater than 30%. Although there are no comparative studies evaluating outcomes between patients who receive additional stenting and those who do not, a multidisciplinary approach that includes stenting or surgical bypass after surgical release has demonstrated high rates of symptomatic relief (75%) and freedom from reintervention (64%) at six months. Nonoperative management of MALS includes supportive measures such as counseling, analgesia, and dietary modifications, but there is a lack of prospective studies comparing surgical and nonsurgical treatment methods, with limited descriptive reports available. In a retrospective study of 67 patients, 24 were managed nonoperatively with various approaches, and while one-third reported symptom improvement, 93% of those who underwent operative management experienced similar benefits; however, statistical significance was not assessed as it was not the focus of the study.

Sunohara et al. (2023) describe celiac artery compression syndrome (CACS) as a condition resulting from the compression of the celiac artery by the median arcuate ligament (MAL), leading to symptoms of intestinal ischemia. However, a definitive approach for the invasive treatment of CACS has yet to be established due to limited treatment indications, particularly regarding the use of endovascular therapy (EVT) with stents as an initial invasive option. The authors present a case involving a 59-year-old male patient who experienced postprandial abdominal pain and was diagnosed with MAL-induced CACS, as indicated by stenosis at the origin of the celiac artery on abdominal contrast computed tomography. Given the patient's awareness of his abdominal pain, the decision was made to proceed with EVT as an invasive treatment. A bare metal stent was successfully placed in the celiac artery, with the lumen adequately dilated using intravascular ultrasound. As a result, the patient reported no further abdominal pain and maintained good stent patency after 15 months. This case suggests that minimally invasive EVT could be considered a first-line treatment for CACS.

Zbinden et al. (2024) investigated the poorly understood pathophysiology and diagnostic processes of MALS by studying 33 consecutive subjects referred to the Department of Angiology at the University Hospital of Zurich over 17 years. Among these, 8 patients (24.2%) were diagnosed with MALS, confirmed through consistent imaging results from color duplex ultrasound, CT, and MRI, which indicated significant stenosis. Seven patients underwent surgical intervention, including laparoscopic, laparotomy, and robot-assisted techniques, with only two (28.6%) experiencing symptom relief post-surgery. Additionally, two patients required angioplasty with stenting, but none found relief from this secondary intervention, despite stent patency. The study noted a similar prevalence of psychiatric disorders in both diagnosed and undiagnosed patients (38% vs. 36%). While the findings confirmed the consistency of sonographic and CT/MRI results, the majority of patients without MALS were diagnosed with alternative conditions, primarily functional disorders. The authors acknowledged limitations, including a small sample size and a shorter follow-up period of about six months, which may have contributed to the discrepancy in symptom relief compared to existing literature.

Manunga et al. (2024) conducted a single-center, retrospective review to evaluate the impact of celiac artery (CA) compression by the median arcuate ligament (MAL) on technical metrics and long-term CA patency in patients with complex aortic aneurysms undergoing fenestrated/branched endograft repairs (F/B-EVARs) between 2013 and 2023. The study included 180 patients, of whom 78 (43%) had MAL+ anatomy, classified into three grades based on stenosis severity: 33 patients with grade A (≤50% stenosis, ≤3 mm in length), 32 with grade B (50% to 80% stenosis, 3 to 8 mm), and 13 with grade C (>80% stenosis, >8 mm). The median length of CA stenosis was 7.0 mm (IQR, 5.0-10.0 mm). CA was incorporated using fenestrations in 177 (98%) patients. Although increased complexity led to difficulties in CA bridging stent placement in four MAL+ patients, completion angiography confirmed CA perfusion with no endoleak, resulting in a technical success rate of 100%. MAL+ patients were more likely to require bare metal stenting in addition to covered stents (P = .004). The MAL+ group also experienced higher estimated blood loss, longer median operating room time, and increased contrast volume, fluoroscopy dose, and time (P < .001). The 30-day mortality rate was 3.3%, with a higher rate of 5.1% in MAL+ patients compared to 2.0% in MAL- patients. At a median follow-up of 770 days (IQR, 198-1525 days), endograft integrity was maintained in all patients, with CA-related events such as kinking (n = 7), thrombosis (n = 1), and endoleak (n = 2) occurring in 10 patients (5.6%), though only two required reinterventions. Additionally, MAL+ patients exhibited lower long-term survival rates. In conclusion, while CA compression by MAL increases procedural complexity, it does not negatively impact technical success, long-term device integrity, or CA patency compared to patients with MAL- anatomy.

Maddox et al. (2025) discuss the treatment of MALS, emphasizing the need to alleviate symptoms caused by the compression of the median arcuate ligament on the celiac trunk and plexus. Since the first open median arcuate ligament release in 1963, treatment options have expanded to include celiac plexus blocks, celiac angioplasty, celiac bypass, and both open and minimally invasive (robotic/laparoscopic) median arcuate ligament release, with the latter accounting for 97% of procedures performed. While patients with atherosclerotic risk factors may experience poorer outcomes, most patients report symptom relief following MAL release, particularly those with post-exertional pain. The traditional open decompression method involves a midline laparotomy to access and decompress the MAL, with additional neurolysis recommended to address the neurogenic aspects of the syndrome. Recent studies indicate that laparoscopic decompression is becoming the preferred approach due to its associated benefits, such as reduced postoperative morbidity. Comparisons of open and laparoscopic techniques show similar long-term outcomes, although laparoscopic procedures tend to have fewer complications. Robotic-assisted surgeries are still being refined, as they currently involve longer operative times. Revascularization efforts are tailored to individual cases, particularly for patients with persistent symptoms despite initial decompression. The involvement of the celiac ganglion in MALS is supported by findings that celiac ganglion sympathectomy can improve blood flow and alleviate symptoms. Overall, the understanding of MALS is evolving, with a shift towards recognizing the neurogenic components of the disease, highlighting the need for improved diagnostic protocols and treatment strategies to enhance patient outcomes.

According to Scovell and Hamdan (2025), if symptoms persist or narrowing of the celiac artery remains after surgical decompression, additional interventions may be necessary, including ganglionectomy (if not already performed), percutaneous revascularization (such as angioplasty or stenting), or surgical revascularization techniques like interposition or bypass grafting. Interposition surgical revascularization is specifically a bypass procedure aimed at restoring proper blood flow to the celiac artery when the initial median arcuate ligament release does not adequately address severe narrowing or occlusion. While percutaneous transluminal angioplasty (PTA) can serve as a useful adjunct for persistent stenosis, it should not be the sole treatment, as outcomes tend to be poor without prior decompression. The authors advocate for a minimally invasive approach, highlighting that laparoscopic techniques have demonstrated higher rates of immediate symptom relief compared to open surgery. Intraoperative assessment of celiac artery flow is recommended to ensure adequate decompression, and for cases of persistent stenosis or recurrent symptoms, options include ganglionectomy, percutaneous revascularization, or surgical revascularization.

Celiac Plexus Block

Skelly and Mak (2021) state that symptomatic MALS is a "controversial diagnosis that should be considered in patients with chronic abdominal pain of unknown etiology despite an extensive medical evaluation. Once suspected, patients should undergo mesenteric duplex ultrasound. Diagnosis is confirmed with elevated celiac artery velocities which normalize with deep inspiration followed by CT angiogram showing the typical "J-hook" conformation of the celiac artery. Patients should then undergo evaluation by a multi-disciplinary team to appropriately select and prepare patients for potential surgical treatment. Surgical options include release of the median arcuate ligament, with or without neurolysis of the celiac nerve plexus, and with or without concomitant revascularization procedures. Approaches can be open, laparoscopic, or robotic. Surgical treatment has an overall success rate of 70-80% with patients reporting improved abdominal pain and quality of life. Post-operatively, patients can have persistent or recurrent abdominal pain and should undergo re-evaluation for possible need for a revascularization procedure for stenosis of the celiac artery or celiac plexus block if the celiac artery flow is normalized. Additionally, some patients will have persistent pain consistent with functional gastrointestinal disorder (FGID) that will then require medical management. Psychiatric comorbidities have been identified as a predisposing factor that may predict poorer outcomes, and there are preliminary findings suggesting that patients with dysautonomia diagnoses may have worse outcomes as well".

Metz et al. (2022) conducted a systematic review to evaluate the efficacy of treatments for MALS. The review included various treatment modalities, such as celiac artery release, celiac plexus resection, and celiac plexus blockage. It analyzed studies published from 1963 to July 2021 that reported on patients with abdominal symptoms and imaging-confirmed MALS, with a minimum of 3 patients per study. A total of 38 studies involving 880 adult patients and 6 studies with 195 pediatric patients were included. The findings indicated that the majority of adult studies reported over 70% symptom relief from 3 to 228 months post-treatment, with 2 studies also noting improved quality of life (QoL). In pediatric studies, half reported similar symptom relief after laparoscopic celiac artery release, with four studies indicating improved QoL. However, 92% of adult studies and 83% of pediatric studies exhibited a high or unclear risk of bias according to the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) criteria, and the significance of celiac plexus resection or blockage could not be clearly established. The review concludes that while there is evidence of sustainable symptom relief exceeding 70% following MALS treatment, the high risk of bias and heterogeneity in inclusion criteria and outcome measures preclude a formal meta-analysis. The authors recommend addressing reporting standards, outcome definitions, and intervention descriptions to enhance patient care, followed by conducting a randomized controlled trial. 

DeCarlo et al. (2023) sought to clarify the optimal approach to median arcuate ligament release (MALR) and its outcomes, as prior research was limited to institutional case series. They analyzed data from the Vascular Low Frequency Disease Consortium, which included 516 patients treated at 24 institutions between 2000 and 2020, with 44.0% undergoing open MALR, 45.5% laparoscopic, and 10.5% robotic procedures. Among the 488 patients (94.6%) with follow-up data, 58.8% experienced full relief, 24.4% had partial relief, and 16.8% reported no benefit from MALR. The study found a 3-year freedom from treatment failure of 51.9% (95% confidence interval, 46.1%-57.3%). Factors associated with an increased hazard of treatment failure included robotic MALR, a history of gastroparesis, abdominal cancer, dysphagia or odynophagia, lack of relief from a celiac plexus block, and a greater number of pain locations. Conversely, older age and a higher number of preoperative diagnostic gastrointestinal studies were linked to a lower hazard of failure. Notably, no radiographic parameters were found to influence treatment failure rates. The findings indicated no significant difference in long-term outcomes between open and laparoscopic MALR, although open procedures were associated with higher perioperative morbidity. The authors recommend utilizing preoperative celiac plexus blocks for patient selection and counseling candidates about the factors influencing treatment failure and the overall high failure rate.

A percutaneous celiac ganglion block may be utilized as a provocative physiological test, based on the premise that symptoms of MALS may arise from inflammation and compression of the celiac plexus nerve fibers. This procedure involves a CT-guided percutaneous injection into the celiac ganglion using local anesthetics like lidocaine or bupivacaine for short-term pain relief, with the option of using ethanol for permanent nerve blockade if the initial block is successful. A positive response to the celiac ganglion nerve block may help identify patients who are likely to benefit from surgical intervention. Factors associated with treatment success or failure were evaluated in an international, multi-institutional cohort of 516 patients who underwent open, laparoscopic, or robotic median arcuate ligament release over a 20-year period. Factors linked to treatment success included increasing age and a greater number of preoperative diagnostic gastrointestinal studies, while factors associated with treatment failure included a robotic approach, gastroparesis, abdominal cancer, dysphagia and/or odynophagia, lack of relief from a celiac plexus block, and an increasing number of preoperative pain locations. Although these features can provide some guidance, the quality of the data is low due to the small size of the study and other factors (Scovell and Hamdan, 2025) .

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References