Embolic stroke as a late complication of inferior vena cava thrombosis.

Sir,

We read with interest the article entitled “Inferior vena cava thrombosis in young adults – a review of two cases” by McAree et al. in the May 2009 Journal1. In addition to the complications they describe, we recently encountered an unusual and late complication of the condition.

A 73 year old male in sinus rhythm with history of 2 embolic strokes underwent trans-oesophageal echocardiography (TOE) after trans-thoracic echocardiography demonstrated an aneurysm of the inter-atrial septum, a finding often associated with patent foramen ovale (PFO). Of note, the patient had suffered two episodes of extensive deep venous thrombosis of the legs some 44 years previously and had stopped taking aspirin prescribed for cardiovascular risk just before the first stroke.

Initial TOE saline contrast study demonstrated a PFO with right to left flow. Colour Doppler interrogation revealed a high velocity jet (1.75ms−1) entering the right atrium from the inferior vena cava (IVC). It impacted on the inter-atrial septum and crossed into the left atrium continuously via the PFO (Figure 1, panel A, arrow). The jet could be traced back for a few centimetres into the IVC before it seemed to disappear.

FIGURE 1

Panel A: IVC: inferior vena cava, LA: left atrium, RA: right atrium, Arrow: Jet crosses patent foramen ovale. Panel B: Arrow: Inferior vena cava stenosis.

A computed tomography scan of abdomen showed a long stenosis of the IVC just above the right renal artery (Figure 1, panel B, arrow). There was accumulation of contrast in the IVC consistent with a severe stenosis. The remainder of the examination was normal.

The aetiology of the IVC stenosis was unclear; a congenital stenosis would usually be associated with prominent collateral veins that were not present in this case. A spontaneous thrombosis of the IVC is very rare as discussed by McAree et al1. It seems most likely that the stenosis represented organised thrombus related to his previous extensive DVTs.

No other potential cause of embolic stroke was found. He was commenced on Warfarin after the TOE and remains well PFO is a well recognised cause of cryptogenic stroke2 with paradoxical embolus being facilitated by an increase in right atrial pressure, in this case, the jet effect of the IVC stenosis. A MEDLINE search failed to find any other examples of this association in the literature.

We note that in their discussion, McAree et al. have listed pulmonary embolus as a recognised complication of the condition but PFO (present in up to 25% of the population) could potentially allow systemic embolisation of recent IVC thrombus or in our patient's case, potentially facilitate embolic stroke many years later in association with a jet effect from an IVC stenosis.