Abstract
Objective Carbon dioxide (CO2) is used as an alternative contrast agent in angiography for patients with iodinated contrast allergy or impaired renal function. CO2 angiography is contraindicated in cerebral circulation based on demonstrated neurotoxicity in animals.1 2 We present a case of reversible neurological complications post CO2 angiography and iodinated contrast.
Methods and Results A 65-year-old man presented with an ischaemic finger from steal syndrome post-arteriovenous fistula ligation, on a background of end-stage renal disease and type 2 diabetes. He underwent CO2 angiography for evaluation of right upper limb circulation. Immediately after the first CO2 injection into the right brachial artery, he became unresponsive and spontaneously recovered after 1-minute. Due to poor distal opacification with CO2, 15ml of iodinated contrast was administered. At 3-hour post-procedure, he developed left facial droop, left hemiparesis and left visual neglect. CT brain, angiogram and perfusion study at 5-hour post-procedure showed no acute changes. Overnight, he worsened to dense left hemiplegia. Non-contrast CT brain at 11-hour post-procedure showed oedema and hyperdensity in the right hemisphere. He had a seizure on day 1 post-procedure. MRI brain performed 24-hour post-procedure showed dramatic resolution of right hemispheric cerebral oedema with no diffusion restriction. All neurological deficits completely resolved 7-day post-procedure.
The CO2 which refluxed into the cerebral circulation from the brachial artery, caused the breakdown of blood-brain barrier, allowing penetration of iodinated contrast and subsequent right hemispheric cerebral oedema.
Conclusions This case highlights the risk of air embolism and neurotoxicity of CO2 angiography and the rare occurrence of contrast-induced encephalopathy.
References
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Kozlov DB, Lang EV, Barnhart W, et al. Adverse cerebrovascular effects of intraarterial CO2 injections: development of an in vitro/in vivo model for assessment of gas-based toxicity. Journal of Vascular and Interventional Radiology: JVIR 2005;16(5):713–26. doi: 10.1097/01.Rvi.0000153114.05700.61 [published Online First: 2005/05/06]