Case presentation:
A 40-year-old lady, presented to the hospital with 1-week history of generalized abdominal pain, moderate to severe in intensity, associated with nausea and 4 episodes of vomiting, with no aggravating or relieving factors. There was no history of fever, hematemesis, bleeding per rectum, chest pain or palpitations. Patient was a known case of hypothyroidism, vitiligo, and type 1 diabetes mellitus. She was a non-smoker. Patient had no personal or family history of thrombophilia and there was no history of recurrent abortions. Physical examination revealed an afebrile patient, with heart rate of 92 beats per minute, blood pressure 124/76 and respiratory rate 17 breaths per minute. Abdominal examination showed diffuse tenderness, no organomegaly, normal percussion note with normal bowel sounds. Cardiac, respiratory and nervous system examination as normal.
Labs investigations showed mild neutrophilic leukocytosis, high C-reactive proteins, microcytic anemia, normal urea, creatinine, electrolytes and liver function tests (table 1). Coagulation testsing showed normal PT, aPTT and INR (Table 2).
A computed tomography (CT) scan of abdomen with contrast showed diffuse thickening of the splenic flexure, descending colon and sigmoid colon with surrounding mesenteric oedema and fat stranding as well as a thrombus in the abdominal aorta at the level of L3 vertebra (Figure 1,2). However, all the thrombophilia screen and autoimmune work up was negative (Table 3).
Patient was managed as a case of ischemic colitis due to spontaneous abdominal aorta thrombosis. She was started on anticoagulation with warfarin bridged by therapeutic dose enoxaparin with a target INR of 2-3. A follow up CT-Scan of abdomen that was done 2 months afterwards showed resolution of thrombus and improvement of the inflammatory changes in the bowel (Figure 3). Three months afterward, she presented with left sided abdominal pain, nausea and vomiting. CT scan of the abdomen was done, and it showed Focal segmental circumferential mural thickening of the distal descending colon as a complication of the ischemic colitis the patient was admitted and underwent left hemicolectomy. She was then discharged home after improvement.
Discussion:Spontaneous arterial thrombosis is rare in occurrence, but It has a significant clinical importance as it leads to several complications’ secondary to blood flow impediment (3). It can involve any organ system with the resulting ischemia and/or infarction. Prompt diagnosis and management is always needed as any delay can cause acute complications which can include renal infarction, stroke, abdominal and peripheral ischemia with gangrene, and might eventually lead to death. Presentation depends on the system or the organ involved (3). Clinically significant thrombosis can be because of a primary hypercoagulable state or as secondary to trauma, immobilization or other coagulopathic abnormalities. Suspicion should arise towards an underlying abnormality whenever a patient has history of unprovoked arterial or venous occlusion. Evaluation for causes such as factor V Leiden, antithrombin III deficiency or protein C or S deficiency is warranted in unprovoked cases (4).
Spontaneous abdominal aorta thrombosis is rare as the blood flowing in the aorta has a high velocity which, along with high caliber of the artery, makes it less prone to thrombosis and it is almost always secondary to an underlying hypercoagulable status. (5) It can present with manifestations that could range from asymptomatic in cases of chronic thrombosis to a more severe one in patients with acute thrombosis which can lead to devastating results with hemodynamic instability and even peripheral or abdominal organ loss. (6) As the abdominal aorta is the major source of arterial supply, its involvement can lead to renal artery ischemia with renal infarction, colonic ischemia, and limbs ischemia. Diagnosis should always be prompt. Initial evaluation should start with basic laboratories such as CBC, which can show increased white cell count, increased lactate denoting ischemia, acute kidney injury or liver injury. Urgent imaging evaluation should be done next. CT scan with contrast is usually the imaging diagnostic of choice as it can reveal the thrombus and allow prompt diagnosis of any underlying complication. CT scan can also help in excluding other diagnoses. (7) A full and thorough evaluation for possible underlying hypercoagulability must be sought. Treatment should be pursued as soon as possible, and it usually depends on the presentation and hemodynamic stability. Usually, the approach in stable patients with an established thrombus is to start on anticoagulation with warfarin and bridging enoxaparin (8). There is currently limited date at present on the novel anticoagulants use in hereditary thrombophilia’s and in spontaneous aorta thrombosis. The duration of anticoagulation is usually guided by the underlying cause, as some patients require life-long anticoagulation for prophylaxis (9).