Chronic mesenteric ischaemia

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Chronic mesenteric ischaemia is usually atherosclerotic narrowing of the superior mesenteric and coeliac arteries that prevents the normal rise in intestinal blood flow after eating. Collaterals often compensate for a single lesion, so multivessel disease produces the most reliable clinicoradiological diagnosis. Patients reduce meal size or avoid food because pain starts after eating, leading to weight loss and malnutrition. Nausea, diarrhoea or constipation can predominate, and normal endoscopy does not exclude vascular disease. Median arcuate ligament compression, vasculitis and non-atherosclerotic arteriopathy are alternative mechanisms, but anatomical coeliac compression is common in asymptomatic imaging and requires careful exclusion of other causes.

Diagnosis joins symptoms to haemodynamically relevant disease and excludes competing abdominal pathology. ESVS 2025 defines a robust multivessel threshold and a more cautious isolated-SMA threshold because overtreating incidental stenosis exposes patients to procedural risk. Duplex is a useful fasting screen but is limited by bowel gas, obesity, respiration and laboratory-specific velocity cut-offs. CTA confirms ostial calcification, lesion length, collateral pathways and suitability for intervention. Endovascular SMA stenting offers lower early burden and is preferred for suitable anatomy; open bypass has greater physiological cost but may provide durable rescue after endovascular failure. Secondary vascular prevention and surveillance matter because this is systemic atherosclerotic disease.

Key points

Think of CMI in reproducible postprandial abdominal pain, food avoidance and weight loss, particularly with smoking or atherosclerosis elsewhere; the classic triad is helpful but not required.
Current ESVS thresholds require symptoms plus vascular disease: CMI is recommended as present with more than 50% SMA stenosis and more than 50% in another mesenteric artery; it may be considered with symptoms and more than 70% isolated SMA stenosis.
In severe CMI with severe weight loss, diarrhoea or constant pain, do not delay urgent revascularisation for nutritional improvement; when suitable anatomy requires treatment, use an endovascular-first strategy with routine stenting rather than balloon angioplasty alone and revascularise at least the SMA.
Begin with mesenteric duplex after at least four hours fasting when local expertise is available, then use CTA as the preferred diagnostic and treatment-planning test and to exclude alternative abdominal disease.
Refer suspected disease to a specialist centre offering multidisciplinary assessment and both endovascular and open revascularisation; an imaging stenosis alone does not prove the pain mechanism.
Revascularise symptomatic multivessel disease and treat at least the SMA. For suitable anatomy requiring treatment, ESVS 2025 recommends an endovascular-first strategy and routine stenting rather than balloon angioplasty alone.
Open revascularisation remains appropriate for fit patients after failed endovascular treatment or when endovascular treatment is infeasible or contraindicated.
After treatment, review symptoms and image during the first year; recurrent symptoms prompt duplex first, CTA to confirm restenosis and consideration of endovascular-first treatment for symptomatic restenosis.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Atherosclerotic occlusive disease

Calcified ostial stenoses affect the SMA and coeliac artery, usually as part of systemic vascular disease.

Median arcuate ligament compression

Respiratory coeliac compression may cause symptoms only after other explanations are excluded by an expert MDT.

Inflammatory or non-atherosclerotic disease

Vasculitis narrows inflamed vessels, while dissection, dysplasia and radiation damage alter arterial structure; each needs mechanism-specific imaging and treatment.

Progression to thrombosis

Plaque rupture or low flow can thrombose a chronically narrowed artery, converting predictable meal-related pain into constant bowel-threatening ischaemia.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Demand-supply mismatch
Digestion raises splanchnic oxygen demand, but stenosed arteries cannot augment flow sufficiently, producing pain shortly after a meal.
2
Collateral compensation
Pancreaticoduodenal and marginal arterial arcades can bypass one stenosis; symptoms become more likely when disease compromises several inflow routes.
3
Adaptive food avoidance
Patients learn that larger meals provoke pain, so they reduce portions or stop eating and develop progressive malnutrition and frailty.
4
Acute-on-chronic failure
Superimposed thrombosis or systemic hypotension exhausts limited collateral flow, changing reversible postprandial ischaemia into acute transmural bowel injury.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Intestinal angina

Pain usually begins 10–30 minutes after meals, lasts up to several hours and becomes reproducible. Patients adapt by eating less, which distinguishes food fear from primary anorexia.

Weight loss and altered bowel habit

Unintentional weight loss supports demand-related ischaemia but also raises malignancy and malabsorption differentials. Diarrhoea, nausea or constipation can accompany pain and may obscure the vascular pattern.

Systemic atherosclerosis

Smoking, coronary disease, peripheral arterial disease, carotid disease, hypertension and dyslipidaemia increase pre-test probability. An abdominal bruit is neither sensitive nor specific.

Severe or unstable phenotype

Constant pain, severe weight loss, diarrhoea and inability to eat indicate severe CMI; sudden worsening, peritonism or physiological disturbance suggests acute thrombosis on chronic stenosis.

Incidental stenosis

Asymptomatic single-vessel disease is common and does not justify intervention. Asymptomatic multivessel disease needs symptom counselling and cardiovascular secondary prevention, with individual review before major abdominal surgery that may disrupt collaterals.

Red flags requiring action

New constant pain replacing episodic postprandial pain, rest pain or rapidly escalating analgesic need suggests acute-on-chronic ischaemia.
Severe weight loss, persistent diarrhoea and inability to maintain intake define severe CMI in the ESVS urgent-treatment recommendation; feeding first can increase demand and delay reperfusion.
Peritonism, acidosis, shock or CT signs of bowel hypoenhancement, pneumatosis or portal gas require the acute mesenteric ischaemia pathway.
An isolated coeliac stenosis without a compatible syndrome is often incidental; unexplained pain still needs assessment for malignancy and gastrointestinal alternatives rather than reflex stenting.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Fasting mesenteric duplex ultrasoundFirst stepFirst line
Why
First-line examination after at least four hours fasting in suspected CMI when performed by an experienced laboratory.
Interpretation and limitations
Elevated velocities and turbulence suggest stenosis, but criteria vary by centre and respiration, obesity and bowel gas affect quality. A positive or inconclusive study needs cross-sectional angiography.
02
CT angiography of mesenteric vesselsPreferred
Why
Preferred test to diagnose disease, exclude alternative intra-abdominal pathology and plan access, stent or bypass anatomy.
Interpretation and limitations
Relate percentage stenosis to symptoms: >50% SMA plus >50% another mesenteric artery supports CMI; >70% isolated SMA disease may support it only after careful multidisciplinary assessment.
03
Contrast-enhanced MR angiography
Why
Alternative anatomical test when CTA is contraindicated and local image quality is adequate.
Interpretation and limitations
It avoids ionising radiation and iodinated contrast but can be affected by motion and may be less practical for calcified ostial planning.
04
Targeted gastrointestinal exclusion tests
Why
Select endoscopy, coeliac testing, pancreatic or malignancy assessment according to symptoms while avoiding prolonged sequential delay in severe disease.
Interpretation and limitations
A competing diagnosis can explain symptoms; a normal gastrointestinal work-up does not negate threshold-matching mesenteric disease.
05
Cardiovascular and operative-risk assessment
Why
Characterise smoking, lipids, diabetes, renal, cardiac and pulmonary disease and determine suitability for endovascular or open treatment.
Interpretation and limitations
Comorbidity supports systemic atherosclerosis and shapes access and anaesthesia; it should not become a reason to leave severe threatened disease untreated.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Upper gastrointestinal disease

Peptic ulcer, gallstone and gastric disorders can cause meal-related pain; targeted endoscopy or hepatobiliary imaging distinguishes their characteristic patterns.

Malignancy

Weight loss and altered bowel habit require appropriate cancer assessment, but severe vascular features should not wait.

Chronic pancreatitis

Chronic pancreatitis also produces meal-related pain, weight loss and diarrhoea; pancreatic calcification, duct change and exocrine insufficiency support it.

Functional abdominal pain

Consider only after organic disease has been assessed; documented vascular thresholds still require expert causal judgement.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01Worked diagnostic casePostprandial pain with multivessel diseaseFirst stepA smoker has reproducible pain after meals, food avoidance and weight loss; fasting duplex suggests SMA and coeliac disease.

1Recognise a compatible chronic syndrome and expedite CTA, while screening for plausible gastrointestinal alternatives without delaying a severe presentation.
2On CTA, confirm more than 50% SMA stenosis plus more than 50% stenosis in another mesenteric artery; this symptom-and-multivessel combination meets the ESVS recommended diagnostic threshold.
3Discuss in a specialist multidisciplinary centre and offer revascularisation, targeting at least the SMA; use endovascular-first treatment when anatomy is suitable.
4Verify symptom response, nutritional recovery and stent patency, while continuing systemic atherosclerotic secondary prevention.

02Preferred revascularisationStable symptomatic CMI suitable for stentingPreferredThreshold-matching symptomatic disease requires intervention and CTA shows an endovascularly accessible SMA lesion.

1Optimise hydration and cardiovascular risk, but do not postpone urgent reperfusion for nutritional loading in severe weight loss, diarrhoea or constant pain.
2Cross the lesion and use routine mesenteric artery stenting rather than balloon angioplasty alone, with the SMA as the primary target and additional vessels selected individually.
3Use the specialist antithrombotic plan after stenting; ESVS says a short course of aspirin plus clopidogrel for a minimum of one month may be considered, while acknowledging evidence is extrapolated and very low.
4Arrange clinical and imaging assessment in the first year and educate the patient to report recurrent postprandial or constant pain promptly.

03Alternative and recurrent diseaseWhen endovascular treatment is unsuitable or symptoms recurAlternativeEndovascular access fails, anatomy is unsuitable, treatment is contraindicated, or symptoms return after revascularisation.

1For a fit patient with an ongoing indication, consider open revascularisation after failed endovascular treatment or when it is infeasible or contraindicated.
2For recurrent symptoms, obtain mesenteric duplex first and CTA when duplex diagnoses or strongly suggests restenosis.
3If restenosis is symptomatic and treatment is appropriate, consider endovascular revascularisation first; do not treat an imaging restenosis without matching symptoms automatically.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Acute mesenteric infarction

Thrombosis across a critical plaque or falling systemic pressure can abruptly overwhelm collaterals and cause irreversible intestinal infarction.

Severe malnutrition

Progressive food avoidance produces protein-energy deficiency, micronutrient depletion, sarcopenia and poorer tolerance of intervention or subsequent illness.

Recurrent stenosis

Neointimal growth or progressive atherosclerosis can narrow a treated segment, returning postprandial symptoms and risking acute stent occlusion.

Systemic vascular events

Mesenteric atherosclerosis marks systemic plaque burden, so myocardial infarction, stroke and limb ischaemia remain major competing long-term hazards.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Document postprandial pain frequency, meal size, weight trajectory and bowel habit; symptom relief is a key measure that the treated lesion was causal.
Monitor renal function and access-site or bleeding complications after contrast and intervention, especially in patients with diffuse vascular disease.
Review cardiovascular prevention, smoking status, blood pressure, lipids and diabetes because future risk extends beyond the mesenteric circulation.
Use clinical and imaging assessment during the first year after open or endovascular revascularisation; investigate recurrent symptoms rather than relying on routine anatomy alone.
Escalate new constant pain, peritonism or metabolic deterioration to the acute mesenteric ischaemia pathway immediately.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

The threshold is clinicoradiological

The >50% multivessel and >70% isolated-SMA cut-offs apply only with chronic abdominal symptoms. They are not screening indications for stenting asymptomatic people.

Fasting matters for duplex

At least four hours fasting reduces bowel contents and postprandial flow variability. Even a technically good study remains a screen interpreted with local velocity criteria.

Nutrition can become hazardous delay

Severe weight loss normally invites feeding, but severe CMI needs reperfusion first because feeding increases intestinal demand and postponement risks acute infarction.

SMA is the core target

The SMA supplies most postprandial small-bowel demand and should be revascularised at minimum in multivessel CMI; additional coeliac treatment depends on anatomy and collateral needs.

Restenosis becomes important when symptomatic

Surveillance anatomy must be joined to recurrent symptoms. Duplex followed by CTA defines a treatable lesion; endovascular treatment is again the preferred first approach where suitable.

11Common pitfallsFrequent interpretation and management errors.

01
Diagnosing CMI from an incidental coeliac stenosis without compatible symptoms or exclusion of common abdominal causes causes overtreatment.
02
Demanding the complete triad of pain, weight loss and bruit misses patients with diarrhoea, nausea or atypical pain.
03
Using a non-fasting duplex velocity from an inexperienced service as definitive ignores substantial technical and physiological variability.
04
Attempting nutritional rehabilitation before urgent reperfusion in severe CMI can worsen demand ischaemia and wastes time.
05
Assuming recurrent pain is automatically stent restenosis misses malignancy, ulcer disease and acute mesenteric ischaemia; reassess clinically and image in sequence.

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