Accidental intra-arterial injection: an under-reported preventable never event

Unusual enhancement patterns from inadvertent arterial contrast injection during CT angiography

Investigation of cerebrovascular incidents typically involve non-contrast intracranial computed tomography (CT) and CT angiography (CTA) of the arch of aorta to vertex with or without CT perfusion. Though rare, inadvertent direct arterial contrast injection is a potentially serious complication which can alter contrast distribution and timing resulting in non-diagnostic intracranial studies. If unnoticed, they can be misinterpreted as pathology leading to further unnecessary investigations, increasing patient radiation dose and delaying appropriate management. To date, there have been two documented case reports describing arterial contrast injection in cerebral CTA or CT perfusion. We describe two further cases of arterial contrast administration. Furthermore, by describing various contrast enhancement patterns in normal and variant anatomy - such as bovine aortic arch, vertebral artery dominance, posterior inferior cerebellar artery (PICA) continuation of vertebral artery and fetal posterior communicating artery (PCOM) - we hope to improve clinician recognition of inadvertent arterial contrast injection in a timely fashion.

The incidence, significance, and management of accidental intra-arterial injection: a narrative review

This narrative review discusses the incidence, risk factors, mechanisms of injury, complications, and treatment regimens for accidental intra-arterial injection of medications. Despite awareness of the issue and the establishment of safety recommendations by national agencies, accidental iatrogenic intra-arterial injection of medications continues to occur. Most of these injuries are caused by accidental injection into an established arterial cannula or the inadvertent and unrecognized cannulation of an artery instead of a vein. Although many medications have been injected into arteries without significant consequence, a number of drugs are consistently associated with severe morbidity, including the need for amputation, making early incident recognition and treatment vital. Accidental intra-arterial injection of medications has also been increasingly reported in those who use illicit drugs, as these intravenous injection attempts can be misdirected into an artery. These reports have improved understanding of these injuries and possible treatment modalities. While the characteristics of injuries from illicit injections are diverse and the optimal treatment modalities are still uncertain, a regimen that includes anticoagulation and intra-arterial injection of thrombolytics and prostaglandins may improve outcomes. Steroids, vasodilators, and sympathetic blocks do not appear to influence amputation rates. Owing to the small and sporadic number of cases, no definitive clinical trial evidence exists, but the treatment modalities found to be useful in the illicit intra-arterial injection group may benefit treatment of similar iatrogenic injuries.