Hope Hospital, Salford, Manchester, UK
SIR, A 50-yr-old lady presented to the out-patient department at Hope Hospital in Salford, Manchester in October 2000 with a 2-yr history of weight loss, poor appetite and chronic cough (which she related to her long history of smoking since age 14). She denied any gastrointestinal symptoms, skin rash, muscle pain or weakness. No relevant family history was found and she was not on any regular medications. Although her clinical examination was unremarkable, as well as her routine haematological and biochemical tests, she had raised inflammatory markers [erythrocyte sedimentation rate (ESR): 63 mm/h; C-reactive protein: 95 mg/l].
She was thoroughly investigated for possible vasculitis, coeliac disease or inflammatory bowel disease [with autoimmune screening for antinuclear antibodies (ANA), anti-DNA, rheumatoid factor, extractable nuclear antigens, antineutophil cytoplasmic antibodies (ANCA), anti-smooth muscle antibodies, anti-mitochondrial antibodies, anti-KLM antibodies and anti-gliadin antibodies]. The immunology screen revealed positive pANCA of 1/256 and positive anti-gliadin antibodies. She had a normal chest radiograph, CT chest scan, bronchoscopy, duodenal and rectal biopsies.
She was started on empirical oral steroid therapy (prednisolone at 40 mg/day with gradual tapering over 2 months, then a maintenance dose of 10 mg/day was continued for another 4 months) for a presumed vasculitis. Ultrasound followed by CT scan of her abdomen in November 2000 showed a splenic haematoma (which regressed on follow-up ultrasonography) with reactive thrombocytosis.
In December 2000 she developed a reversible right hemiparesis with a normal CT brain scan. At this stage, an echocardiogram was performed. Despite a relatively normal transthoracic echocardiogram (TTE), the trans-oesophageal echocardiogram (TOE) detected an ascending aortic pedunculated mural thrombus. Surprisingly, magnetic resonance imaging of the thoracic aorta and its branches was normal. Cardiologists suggested long-term anticoagulation with low molecular weight heparin (then with warfarin), aspirin and clopidogrel, which were started by mid-December following the TOE findings.
At the end of December 2000 she suddenly developed an acute abdomen. An urgent laparotomy detected faecal peritonitis and a small intestinal oedematous segment that necessitated a 2-m small bowel resection with ileostomy and mucous fistula. After 2 weeks in intensive care she was transferred to the ward on total parenteral nutrition. A thrombophilia screen (including anti-thrombin 3, protein C and S, lupus anticoagulant, activated protein C reaction and homocysteine) was normal. A repeated pANCA was only 1/64 and a second opinion of her duodenal and rectal biopsies confirmed absence of histological evidence of vasculitis. Fortunately, she had a smooth 4-month rehabilitation course after which she was able to have a successful small bowel re-anastomosis in May 2001.
Clinicians have long recognized that the atherosclerotic abdominal aorta is an important source of thrombus and debris which may embolize distally. While the dissemination of fine atherosclerotic debris causing patchy, painful cyanosis and gangrene of the foot has been most frequently described, large single vessel occlusions caused by the dislodgement of a large plaque or mural thrombus have also been reported [1].
Cholesterol microembolism may produce a variety of signs and symptoms resembling a multisystem disorder such as a systemic vasculitis. Laboratory abnormalities contributing to the diagnostic confusion include leucocytosis, eosinophilia, hypocomplementaemia, ESR elevation, ANA and rheumatoid factor positivity [2].
Aortic mural thrombus has been reported to present as polyarteritis nodosa (pseudovasculitis) [3]. Furthermore, a patient with a syndrome mimicking polyarteritis nodosa was found to have bilateral atrial myxomas [4]. Despite positive pANCA, the patient did not have any history of asthma to suggest ChurgStrauss syndrome. In addition, microscopic polyarteritis was unlikely with absence of evidence of renal involvement and with negative hepatitis B serology. It has been noted that hypercoagulable states have not previously been associated with aortic arch thrombus [5].
The use of TTE is a reasonable first approach in investigating patients with peripheral emboli. The TTE may reveal an unsuspected cardiac source of emboli. However, TTE may be false negative or unreliable for technical reasons. Patent foramen ovale, left atrial appendage thrombosis and intra-atrial thrombi are often missed by TTE. It is also less sensitive to valvular vegetations. A normal TTE must be followed by a TOE if such lesions are suspected. TOE was highly indicated in this particular patient in view of her young age to rule out a cardiac source of probable thromboembolic stroke. The combined use of TTE and TOE presents a somewhat non-invasive diagnostic method of investigating both the heart and the aorta in patients presenting with peripheral emboli, as well as cerebrovascular disease thought to be secondary to emboli originating in the aortic arch [6].
Our patient presented with three embolic episodes causing splenic haematoma, right hemiparesis and intestinal failure. We think that a somewhat earlier TTE and TOE could have saved the patient from investigations trying to confirm the presence of vasculitis as an explanation of her symptoms, signs and immunological markers.
We urge early consideration of echocardiography (TTE then TOE) to detect aortic thrombi in patients presenting with embolic episodes in a clinical situation simulating vasculitis (pseudovasculitis).
Notes
Correspondence to: A. F. A. Helmy. E-mail: afah_99{at}yahoo.com
References