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We present the case of a 67-year-old male with mesenteric venous thrombosis resulting in mesenteric angina, where early diagnosis made a favourable outcome possible through prompt anticoagulation and bowel rest. Mesenteric venous thrombosis is a relatively rare but important cause of bowel ischaemia, as a delay in diagnosis is associated with high morbidity and mortality. Early diagnosis through computed tomography scanning and subsequent treatment resulted in resolution of the thrombus with no long term sequelae.
Mesenteric venous thrombosis (MVT) is an unusual and non-specific cause of abdominal pain, accounting for only 10–15% of cases of mesenteric ischaemia. While MVT only accounts for an estimated 0.006% of all hospital admissions, it is probably more common when one considers the asymptomatic group of patients in whom MVT remains undiagnosed or is an incidental finding on computed tomography (CT) when investigating another intra-abdominal pathology. The high mortality rate at 30 days associated with delayed diagnosis makes it particularly important,1 although MVT carries the best prognosis of all the causes of bowel ischaemia where it is diagnosed promptly. We report a case of superior mesenteric venous (SMV) thrombosis, followed by a discussion of MVT identification and management, with particular focus on bowel rest and anticoagulation.
An otherwise healthy 67-year-old Caucasian man presented with a 1 week history of abdominal pain starting almost immediately after eating and also associated with vomiting. He reported abdominal distension, but his bowels were opening normally with no abnormal stool. Notable medical history included deep venous thrombosis and three vessel coronary artery disease, for which he was on aspirin, pravastatin, atenolol, and amlodipine. There was no history of abdominal surgery. He enjoyed an active retirement, being a non-smoker and moderate drinker of alcohol.
The patient had upper abdominal tenderness in an otherwise soft but distended abdomen. Initial work up revealed only an elevated white cell count of 12.5×109/l (normal range (NR) 4.0–11.0×109/l) and C reactive protein of 101 mg/l (normal <10 mg/l), with a normal amylase 43 U/l (NR 0–100 U/L) and normal abdominal and chest radiographs. Lactate, a marker of bowel ischaemia, was elevated at 2.7 mmol/l (NR 0.60–2.0 mmol/l), but inorganic phosphate was measured at 0.64 mmol/l (NR 0.80–1.45 mmol/l).
With a differential diagnosis of mesenteric angina, a contrast enhanced CT scan was performed (fig 1). This confirmed an SMV thrombus, causing mesenteric ischaemia with jejunal oedema and dilatation, with normal mesenteric arteries, mesenteric lymphadenopathy, and a small amount of perihepatic ascites. There was no evidence of pancreatitis.
Intravenous heparin was promptly started, with a target therapeutic activated partial thromboplastin time (APTT) ratio of between 2.0–3.0. A thrombophilia screen was negative. The patient was placed on nil by mouth.
Initially, the patient’s symptoms worsened with per rectum bleeding and vomiting. We monitored for bowel ischaemia with repeat arterial blood gases and signs of peritonism. His abdomen remained soft and non-tender, and he was treated with a nasogastric tube until the vomiting settled. The patient remained haemodynamically stable throughout his admission. He went on to total parenteral nutrition on the fourth day of his admission until his pain improved, and the diarrhoea settled when diet was slowly reintroduced.
The patient was put on lifelong warfarin. A later ultrasound confirmed resolution of his ascites. Follow-up CT scan at 3 months showed an unremarkable abdomen with resolution of the lymphadenopathy, no evidence of intra-abdominal malignancy, and a partial SMV thrombus (fig 2).
Clinical follow-up at 6 months confirmed that the patient was free from symptoms, and had replaced the weight lost.
Although mesenteric ischaemia is associated with a high morbidity and mortality, rapid diagnosis and anticoagulation of MVT has excellent outcomes.1 The literature suggests that of all the causes of mesenteric ischaemia, venous thrombosis carries the best prognosis.2
Patients with non-specific abdominal pain related to eating should be considered for mesenteric ischaemia, and a rapid contrast enhanced CT scan has been shown to have a high diagnostic specificity (100%) and sensitivity (90%).3
While there is much to learn about the natural history of the disease, MVT has been shown to be associated with hypercoagulable states—for example, polycythaemia vera and protein C and S deficiencies. Visceral infection, trauma, surgery, pancreatitis, malignancy and portal hypertension are also linked with MVT, although between 25–50% of cases have no attributable cause.4
Patients with signs of peritonism or extending thrombus have been shown to benefit from endovascular intervention and direct or indirect thrombolysis,5 although thrombolytics carry a higher mortality rate. Signs of extending thrombus are clinical and include haemodynamic instability, failure of symptoms to resolve despite anticoagulation, and peritonism. Surgery is a mandatory option where bowel necrosis is suspected or where frank peritonitis is evident, although this has poorer outcomes.5
The rarity of the disease means there is a lack of consensus in management. Thrombolysis is a development that needs further investigation, and could be useful in MVT that extends or fails to resolve. However, we advocate relatively safe conservative management with rapid and long term anticoagulation with bowel rest, and parenteral nutritional support when early diagnosis is achieved.
Competing interests: None.
Patient consent: Patient/guardian consent was obtained for publication.