[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.

A rare case of a combination of ectopic kidney and medial arcuate ligament syndrome: a case report.

BACKGROUND: Ectopic kidney and median arcuate ligament syndrome are both rare conditions. The clinical presentation and diagnosis of these conditions are not well studied. There are no reports on the combination of these two rare conditions. CASE PRESENTATION: We report a 24-year-old woman with fever, dysuria, urinary frequency and left flank pain for two days. The primary diagnoses in the clinic were left acute pyelonephritis and left hydronephrosis due to throbbing pain in the left costovertebral angle and pyuria. However, further computed tomography showed right ectopic pelvic kidney, left renal pelvis dilatation without definite ureteral lesion, good bilateral renal contrast enhancement, and compression of the celiac axis due to obstruction by the median arcuate ligament. Chronic abdominal symptoms were reported by the patient after repeat history taking. The patient's condition was fully explained and discussed with her and her family, but they refused further therapy. After the acute pyelonephritis began improving, the patient was discharged for follow-up at our outpatient clinic. CONCLUSION: We present an extremely rare case of a combination of two rare conditions: ectopic kidney and median arcuate ligament syndrome. No study to date has reported on the relationship between the two diseases. Given the rarity of the two conditions, no evidence or even a hypothesis exists to explain the possible etiology of their combination. More reports are required to enhance the understanding of these rare conditions.

Atypical case of coexistent vascular compression syndromes: median arcuate ligament syndrome and nutcracker syndrome.

Vascular compression syndromes, including median arcuate ligament syndrome (MALS) and nutcracker syndrome (NCS), are poorly understood and frequently delayed diagnoses. This case describes a young adult female presenting with chronic vomiting, abdominal pain and weight loss, with dependence on nasogastric feeding. Subsequent to her gastrointestinal symptoms, she developed haematuria and orthostatic intolerance. Investigations confirmed NCS and possible MALS, with superadded gastroparesis and bradygastria. Under the joint care of general and vascular surgeons, she underwent a gastrojejunostomy and panelled renocaval bypass which led to partial resolution of her symptoms. It is hypothesised that gastroparesis may have been caused by MALS via a neurogenic mechanism, or coexistent compression of the duodenum by the superior mesenteric artery. This case highlights the difficulty in diagnosis of vascular compression syndromes, the overlap between the conditions and the potential for multiple coexistent conditions which complicate diagnosis and lead to increased lead-time and morbidity for patients.

A Case Series of Median Arcuate Ligament Syndrome With Varied Presentations.

Median arcuate ligament syndrome (MALS) is characterized by the constriction of the celiac trunk caused by fibrous connections originating from the median arcuate ligament (MAL) and diaphragmatic crura. It presents with symptoms often leading to misdiagnosis. In this study, we present three cases of MALS, with distinct manifestations. These cases were diagnosed through comprehensive investigations and managed successfully using laparoscopic decompression. The diagnosis of MALS poses challenges due to its variable presentations and overlap with other conditions. Diagnostic imaging techniques such as Doppler ultrasound, computed tomography (CT) scans and angiography play a role in confirming the diagnosis. Laparoscopic decompression has proven to be a treatment option that relieves symptoms and restores blood flow. This series highlights the importance of considering MALS as a cause for abdominal pain cases. Early detection and the use of diagnostic techniques can result in favorable outcomes.

A fatal case of massive hemobilia caused by invasive pancreatic cancer with median arcuate ligament syndrome: A case report.

INTRODUCTION: In median arcuate ligament syndrome (MALS), the celiac artery is compressed, causing an arcade to develop in the pancreatic head, leading to ischemic symptoms and aneurysms. PATIENT CONCERNS: The patient was diagnosed with borderline resectable pancreatic cancer (PC) and MALS. Endoscopic biliary drainage with a covered metal stent (CMS) was performed for the obstructive jaundice. After the jaundice improved, a modified FOLFIRINOX regimen was initiated. Several days later, cardiopulmonary arrest occurred after hematemesis occurred. Cardiopulmonary resuscitation was performed, his blood pressure stabilized, and emergent upper endoscopy was performed. The CMS was dislodged and active bleeding was observed in the papillae. The CMS was replaced, and temporary hemostasis was achieved. Contrast-enhanced computed tomography revealed a diagnosis of extravasation from the posterior superior pancreaticoduodenal artery (PSPDA) into the biliary tract. Transcatheter arterial embolization was performed. However, the patient was subsequently diagnosed with hypoxic encephalopathy and died on day 14 of hospitalization. DIAGNOSIS: Biliary hemorrhage due to invasion of pancreatic cancer from the PSPDA associated with MALS. INTERVENTION: None. OUTCOMES: Biliary hemorrhage from the PSPDA was fatal in the patient with invasive PC with MALS. LESSONS: Since MALS associated with PC is not a rare disease, the purpose of this study was to keep in mind the possibility of fatal biliary hemorrhage.

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.

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.

Robotic Approach for Median Arcuate Ligament Relief: A Case Report and Literature Review.

Introduction: There are very few reported cases of robotic surgery for median arcuate ligament syndrome. This clinical condition develops when the root of the celiac trunk is compressed by the median arcuate ligament of the diaphragm. The symptoms that typically accompany this syndrome are: discomfort and pain in the upper abdominal region, particularly after eating, and weight loss. During the diagnostic process, it is important to rule out other potential causes and demonstrate compression using any imaging technique available. Transecting the median arcuate ligament is the primary focus of the surgical treatment. We report a case of robotic MAL release, focusing on the particular aspects of the surgical technique. A literature review was also performed on the topic of robotic approach for MALS. Clinical case: A 25-year-old woman presented with sudden onset severe upper abdominal pain after physical activity and eating. She was then diagnosed with median arcuate ligament syndrome by imagistic means with computer tomography, doppler ultrasound, and angiographic computed tomography. After conservative management and careful planning, we performed robotic division of median arcuate ligament. The patient was discharged from the hospital without any complaint on the second day after surgery. Subsequent imaging studies revealed no residual celiac axis stenosis. Conclusion: The robotic approach is a safe and feasible treatment modality for median arcuate ligament syndrome.

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.

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.

Systematic Review of the Efficacy of Treatment for Median Arcuate Ligament Syndrome.

OBJECTIVE: Since the first description of the median arcuate ligament syndrome (MALS), the existence for the syndrome and the efficacy of treatment for it have been questioned. METHODS: A systematic review conforming to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement was conducted, with a broader view on treatment for MALS including any kind of coeliac artery release, coeliac plexus resection, and coeliac plexus blockage, irrespective of age. Online databases were used to identify papers published between 1963 and July 2021. The inclusion criteria were abdominal symptoms, proof of MALS on imaging, and articles reporting at least three patients. Primary outcomes were symptom relief and quality of life (QoL). RESULTS: Thirty-eight studies describing 880 adult patients and six studies describing 195 paediatric patients were included. The majority of the adult studies reported symptom relief of more than 70% from three to 228 months after treatment. Two adult studies showed an improved QoL after treatment. Half of the paediatric studies reported symptom relief of more than 70% from six to 62 months after laparoscopic coeliac artery release, and four studies reported an improved QoL. Thirty-five (92%) adult studies and five (83%) paediatric studies scored a high or unclear risk of bias for the majority of the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) items. The meaning of coeliac plexus resection or blockage could not be substantiated. CONCLUSION: This systematic review suggests a sustainable symptom relief of more than 70% after treatment for MALS in the majority of adult and paediatric studies; however, owing to the heterogeneity of the inclusion criteria and outcome parameters, the risk of bias was high and a formal meta-analysis could not be performed. To improve care for patients with MALS the next steps would be to deal with reporting standards, outcome definitions, and consensus descriptions of the intervention(s), after which an appropriate randomised controlled trial should be performed.

Duodenopancreatectomy for PDAC Associated with MALS: A Case Report.

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive form of pancreatic malignancy which occurs in over 90% of such cases. Pancreaticoduodenectomy (PD) is used with a curative purpose for localized PDAC. Case presentation: A 68-year-old woman presented to our service through a transfer from another service, to be investigated and treated for a head of the pancreas tumor in a tertiary referral hospital. After a complete clinical and paraclinical evaluation, the patient was diagnosed with a PDAC and also with a median arcuate ligament syndrome (MALS). The surgical treatment was considered adequate, therefore, the patient underwent a PD with transmesocolic hepaticojejunostomy, pancreaticogastric anastomosis, precolic end-to-side gastrojejunostomy, Witzel jejunostomy and with the help of the cardiovascular surgery team from the Heart Institute, Cluj- Napoca, an aortohepatic bypass using saphenous vein graft was performed. Conclusion: Bypass was essential because the blood flow in the proper hepatic artery was not restored after sectioning the median arcuate ligament and clamping the gastroduodenal artery. The patient had a favorable outcome. The particularity of the present case consists of the complete occlusion of the celiac trunk by MALS and the total vascularization of the supramesocolic organs due to the superior mesenteric artery through the gastroduodenal artery.

DUNBAR SYNDROME: CLINICAL MANIFESTATION IN ADULTS, DIAGNOSTIC PROBLEMS (CASE REPORT).

In this case we used CBC and biochemical tests, ECG, ultrasound of the abdominal cavity and heart, CT scan with and without IV contrast. Women with complains on recurrent severe abdominal pain in epigastric region and right part of the abdomen radiating to the back, nausea, vomiting. Making laboratory and instrumental tests for confirmation of the diagnosis. Surgical treatment of DS was performed and after one year of the follow up there were no complications. DS may mimic other medical conditions such as gallbladder diseases, gastritis/peptic ulcer, appendicitis, colorectal malignancy, hepatitis, atherosclerotic diseases etc. That is why DS is a diagnosis of exclusion. This case illustrates pathway to find correct diagnosis and improve management tactic.

Plasma α-Glutathione S-Transferase in Patients with Chronic Mesenteric Ischemia and Median Arcuate Ligament Syndrome.

Background: Chronic mesenteric ischemia (CMI) due to either atherosclerosis of the mesenteric arteries or median arcuate ligament syndrome (MALS) is an underdiagnosed entity. The etiology of MALS and its existence have been debated and questioned. We aimed to identify plasma biomarkers indicating mesenteric ischemia in patients with CMI and MALS. Methods: Plasma α-glutathione S-transferase (α-GST), intestinal fatty acid-binding protein (I-FABP), citrulline, and ischemia modified albumin (IMA) were analyzed in fifty-eight patients with CMI (Group A, n=44) and MALS (Group B, n=14) before and after revascularization. The plasma levels of these potential biomarkers were compared with those of healthy individuals (Group C, n=16). Group comparison was performed with the Mann-Whitney U-test. Cross-tabulation and its derivatives were obtained. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were calculated. Results: Plasma levels of α-GST were significantly raised in the patients with CMI (7.8 ng/mL, p<0.001) and MALS (8.4 ng/mL, p<0.001), as compared with the control Group C (3.3 ng/mL). The threshold for normal median plasma α-GST levels of 4 ng/mL yielded a sensitivity of 93% and 86%, specificity of 86% and 88%, respectively, for the diagnosis of CMI due to atherosclerosis and MALS. AUC of ROC curves was 0.96 (p<0.0001) for CMI and 0.85 (p<0.002) for MALS. The patient groups did not differ from the healthy controls in any other biomarkers. Conclusion: Plasma α-GST levels are elevated in CMI and MALS patients. Elevated plasma levels of α-GST suggest ischemia as the etiology of MALS.

Another Sherlock Holmes Mystery: Abdominal Pain Explained by Median Arcuate Ligament Syndrome.

Median arcuate ligament syndrome (MALS), also known as celiac artery compression syndrome, is a rare gastrointestinal condition with an estimated incidence of 2 per 100 000 population. Predominantly in female patients, this syndrome is characterized by the compression of the celiac artery at its origin from the aorta by the median arcuate ligament, which at the same time is entrapping the celiac plexus, causing upper abdominal pain, notably postprandial pain, as well as nausea, vomiting, food aversion, and weight loss. We present a case of abdominal pain secondary to MALS that was appropriately diagnosed after requiring narcotic medication, which responded to surgical therapy.

A diagnostic workup and laparoscopic approach for median arcuate ligament syndrome.

BACKGROUND: Median arcuate ligament syndrome (MALS) is a rare disorder characterized by the compression of the coeliac trunk and plexus by fibrous arches of the median ligament. It commonly occurs in young women with postprandial epigastric pain, weight loss and nausea. We present a single surgeon experience on the diagnostic approach and management of MALS with a focus on laparoscopic surgery. METHODS: A retrospective review of adult patients diagnosed with MALS during a 10-year period (2011-2021) was conducted at Bankstown-Lidcombe hospital in New South Wales, Australia. RESULTS: MALS was diagnosed in six patients (mean 46 years, range: 27-74 years old), all confirmed on mesenteric duplex ultrasound and computed tomography angiography. The most common presentations were women with post-prandial pain, exercise induced pain and an average weight loss of 14.5 kg. The median interval from onset of symptoms to surgical referral was 10.5 months. The average BMI was 24.1 kg/m2 and most had a grade III American Society of Anaesthesiologist physical status. All patients underwent laparoscopic release of median arcuate ligament with one patient requiring endovascular stenting. The mean operative time was 119 minutes with two minor post-operative complications, but no mortalities. The median hospital length of stay was 3.5 days with a median follow up of 3.5 years. CONCLUSION: Laparoscopic median arcuate ligament release with endovascular support for selected cases provides sound clinical resolution of symptoms and long-term results.

Clinico-pathologic findings in patients with median arcuate ligament syndrome (celiac artery compression syndrome).

Median Arcuate Ligament Syndrome (MALS) is a rare entity characterized by severe post-prandial epigastric pain, nausea, vomiting, and/or weight loss. Symptoms have been attributed to vascular compression (celiac artery compression syndrome, CACS), but it remains controversial whether they could be secondary to neural compression. Literature review identified rare description of pathologic findings in surgery journals. The clinico-pathologic findings of four MALS patients who underwent robotic or laparoscopic surgery in our hospital are described. All our patients were female with a median age of 32.5 (range 25-55 years), and a median BMI of 23.5 kg/m2. They presented with chronic often post-prandial abdominal pain (4/4), nausea (3/4), emesis (2/4), anorexia (1/4), and weight loss (1/4). Two patients had a history of Crohn's disease. At intraoperative exploration, the celiac artery and adjacent nerves and ganglia were encased and partially compressed by fibrotic tissue in each patient. In each case laparoscopic excision of fibrotic tissue, celiac plexus and ligament division and was performed; celiac plexus nerve block was also performed in one patient. After surgical intervention, symptoms improved in three of the patients whose specimens show periganglionic and perineural fibrosis with proliferation of small nerve fibers. Our findings support neurogenic compression as a contributing factor in the development of pain and other MALS symptoms, and favor the use of MALS rather than CACS as diagnostic terminology. To further study the pathogenesis of this unusual syndrome, surgeons should submit all tissues excised during MALS procedures for histopathologic examination.

Síndromes compresivos de las arterias viscerales. Síndrome del ligamento arcuato. Síndrome de Wilkie / Compressive syndromes of the visceral arteries. Arcuate ligament syndrome. Wilkie syndrome

Los síndromes compresivos de los vasos sanguíneos a nivel abdominal son entidades nosológicas que se pueden considerar poco frecuentes. La sintomatología clínica en la mayoría de los casos y generalmente se suele llegar al diagnostico descartando otras patologías y utilizando las modernas tecnologías que permiten en la mayoría de los casos llegar a un diagnostico evidenciando el problema compresivo. Su tratamiento, desde el punto de vista conceptual es la descompresión pudiéndose aplicar diferentes alternativas que deben de ser aplicadas, en especial las mas agresivas con una adecuada ponderación de riesgo beneficio, teniendo en consideración los diferentes condicionantes que suelen acompañar a este tipo de problemas. (AU)

Compressive syndromes of the blood vessels at the abdominal level are nosological entities that can be considered infrequent. The clinical symptoms in most cases and generally the diagnosis is usually reached by ruling out other pathologies and using modern technologies that allow in most cases to reach a diagnosis showing the compression problem. Its treatment, from the conceptual point of view, is decompression, and different alternatives can be applied that must be applied, especially the most aggressive oneswith an adequate risk-benefit weighting, taking into account the different conditioning factors that usually accompany this type ofproblems. (AU)

Median arcuate ligament syndrome in a patient with frontal lobe syndrome.

A boy aged 19 years presented to emergency room with severe postprandial upper abdominal pain and recent significant weight loss, with history of decompressive craniotomy for post-traumatic frontal lobe haemorrhage. CT scan revealed an acute indentation of coeliac artery with high-grade stenosis and post-stenotic dilatation, diagnostic of median arcuate ligament syndrome (MALS). MALS, a diagnosis of exclusion, is identified using patient's accurate symptomatic description. Exclusion of other causes of abdominal angina in a patient with frontal lobe syndrome was a challenging job, as they lack critical decision-making ability. Hence, the decision to proceed with the complex laparoscopic procedure was made by the patient's parents and the surgeon, with the patient's consent. Laparoscopic release of the median arcuate ligament resulted in relief of the patient symptoms much to the relief of his parents and the surgeon.

Perioperative Microcirculatory Changes Detected with Gastroscopy Assisted Laser Doppler Flowmetry and Visible Light Spectroscopy in Patients with Median Arcuate Ligament Syndrome.

PURPOSE: Physiological tests may aid in diagnosing median arcuate ligament syndrome (MALS). MALS is a symptomatic compression of the celiac artery causing symptoms similar to chronic mesenteric ischemia (CMI) of atherosclerotic etiology. Simultaneous use of visible light spectroscopy (VLS) and laser doppler flowmetry (LDF) during upper endoscopy may detect microcirculatory changes in these patients. PATIENTS AND METHODS: In a single-center, prospective comparative cohort, 25 patients were evaluated for MALS. Patients with a consensus diagnosis of MALS (n=15) underwent a gastroscopy assisted, transmucosal microcirculatory assessment with LDF and VLS. Results were compared to individuals with normal intestinal circulation (n=38) evaluated with duplex ultrasonography, and to patients with chronic mesenteric ischemia (n=32). Treatment response was evaluated clinically at 1, 3, 6, and 12 months, and with ultrasound, VLS and LDF at three months. Health-related quality of life (QoL) was assessed with Euroqol (EQ-5D-5L), preoperatively, and 12 months postoperatively. RESULTS: Preoperative mean transmucosal oxygen saturation was significantly lower in patients with MALS (SO2 76±6), as compared to healthy individuals (SO2 81±4), p=0.02. An overall significant improvement in SO2 after surgical decompression of the celiac artery was found (SO2 81±3.7, p=0.05). Eleven (92%) patients with clinical improvement after laparoscopic decompression had a definitive diagnosis of MALS. Median follow-up was 18 months (4-24 months). Four of the five dimensions investigated with EQ-5D-5L improved. CONCLUSION: VLS detected a significantly lower baseline transmucosal SO2 in patients with MALS as compared to control subjects with normal intestinal circulation. An improvement in SO2 after laparoscopic decompression was found, supporting a possible ischemic etiology in our patient population.