By Dr Marek Garbowski, Vascular Surgeon, Subiaco
Abdominal vascular compression syndromes are a group of rare conditions in which blood vessels in the abdomen and/or pelvis become compressed by surrounding structures, leading to a range of symptoms.
These syndromes can cause significant discomfort, digestive issues, and even organ dysfunction if left untreated.
The four main types of abdominal vascular compression syndromes are Median Arcuate Ligament Syndrome (MALS), Superior Mesenteric Artery Syndrome (SMAS), Nutcracker Syndrome (NCS), and May-Thurner Syndrome (MTS).
Each has distinct causes, symptoms, and treatment approaches.
Median Arcuate Ligament Syndrome
MALS occurs when the median arcuate ligament, a fibrous band of the diaphragm, compresses the coeliac artery and the surrounding nerve plexus.
This compression may lead to decreased blood flow to the abdominal organs and irritation of the coeliac plexus, causing significant pain and other gastrointestinal symptoms.
Symptoms include chronic abdominal pain, particularly after eating, weight loss due to food avoidance, nausea and vomiting and early satiety.
It is often diagnosed through imaging techniques like duplex ultrasound, CT angiography (CTA), or magnetic resonance angiography (MRA), which reveal extrinsic compression of the coeliac artery.
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A diagnostic coeliac plexus block can also help confirm MALS if it provides temporary pain relief.
The primary treatment for MALS is surgical decompression of the coeliac artery. This typically involves laparoscopic median arcuate ligament release to relieve the compression.
In some cases, additional procedures like coeliac artery angioplasty and stenting may be necessary to restore normal blood flow.
Superior Mesenteric Artery Syndrome
SMAS is a rare disorder in which the superior mesenteric artery (SMA) compresses the third part of the duodenum, leading to partial or complete obstruction of this part of small intestine. The condition is often associated with rapid weight loss, which reduces the fat cushion around the SMA, making compression more likely.
Symptoms include severe postprandial after eating abdominal pain, nausea and vomiting, sometimes bilious, early satiety, significant weight loss, bloating and reflux.
SMAS is diagnosed using contrast-enhanced CT scans, upper gastrointestinal (GI) series, or endoscopy, which reveal narrowing of the duodenum and delayed gastric emptying.
Treatment starts with conservative management, including nutritional support to regain weight and increase retroperitoneal fat, small, frequent meals and nasogastric feeding or total parenteral nutrition in severe cases.
If conservative measures fail, surgical options such as open or laparoscopic duodenojejunostomy or gastrojejunostomy may be necessary to bypass the compressed portion of the duodenum.
Nutcracker Syndrome
This occurs when the left renal vein is compressed between the superior mesenteric artery and the aorta, leading to impaired venous return from the left kidney.
This condition can cause symptoms related to increased venous pressure in the kidney and pelvic venous network.
Symptoms include haematuria without UTI, flank or abdominal pain, especially on the left side, pelvic pain and pressure related discomfort, orthostatic proteinuria, vaginal/labial varicose veins, pelvic varicosities seen during laparoscopy and varicocoele.
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Diagnosis is made through duplex ultrasound, CTA, or venography combined with intravascular ultrasound (IVUS), which demonstrate stenosis of the left renal vein and increased pressure.
Mild cases are managed conservatively with analgesia and trial of micronised purified flavonoid fraction (MPFF) supplements.
Endovascular stenting of the left renal vein to restore normal blood flow remains a controversial option requiring more evaluation. Surgical options include renal vein bypass or renal or left ovarian vein transposition if symptoms persist.
May-Thurner Syndrome
May-Thurner Syndrome (MTS) occurs when the left common iliac vein is compressed by the overlying right common iliac artery against the sacrum, leading to reduced blood flow and an increased risk of deep vein thrombosis.
Symptoms include swelling and pain in the left leg, varicose veins in the pelvic and left lower limb, chronic venous insufficiency and deep vein thrombosis in severe cases
MTS is diagnosed through venous duplex ultrasound, CT venography, or MR venography, which reveal compression of the left common iliac vein and possible DVT.
Treatment includes anticoagulation therapy for established DVT, endovascular treatment using stenting to keep the left common iliac vein open and thrombectomy or thrombolysis if clinically indicated (percutaneous mechanical suction thrombectomy provides improved results and lesser complications rates).
Graduated compression stockings manage lower limb symptoms and minimise the risk of postphlebitic syndrome in DVT patients.
Key messages
- Abdominal vascular compression syndromes are rare but potentially serious conditions that can significantly impact patient’s quality of life. Consider them in unexplained abdominal/pelvic pain, gastrointestinal symptoms, haematuria, or leg oedema
- Early diagnosis and appropriate management are crucial for preventing complications and improving patient outcomes
- While conservative measures may help in some cases, surgical or endovascular interventions are often necessary to relieve vascular compression and restore normal function.
Author competing interests – nil
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