Cerebral arterial gas embolism from attempted mechanical thrombectomy: recovery following hyperbaric oxygen therapy

Abstract

Cerebral arterial gas embolism is a recognised complication of endovascular intervention with an estimated incidence of 0.08%. Its diagnosis is predominantly clinical, supported by neuroimaging. The treatment relies on alleviating mechanical obstruction and reversing the proinflammatory processes that contribute to tissue ischaemia. Hyperbaric oxygen therapy is an effective treatment and has multiple mechanisms to reverse the pathological processes involved in cerebral arterial gas embolism. Symptomatic cerebral arterial gas embolism is a rare complication of endovascular intervention for acute ischaemic stroke. Although there are no previous descriptions of its successful treatment with hyperbaric oxygen therapy following mechanical thrombectomy, this is likely to become more common as mechanical thrombectomy is increasingly used worldwide to treat acute ischaemic stroke.

Unusual Histopathological Findings in Mechanically Removed Stroke Thrombi – A Multicenter Experience

“…An alternative interpretation is that these empty spaces represent air bubbles. Such air emboli are difficult to prove from a histopathological point of view but microscopic, asymptomatic (average diameter 30–60 μm) as well as larger and symptomatic air embolism has been reported in conjunction with cerebral angiography ( 31 – 33 ). This may suggest that the repeated cerebral angiographies resulted in small amounts of air emboli during the MT that either penetrated the occluding thrombus or were incorporated in an occluding but still growing thrombus.…”

Cerebral catheter angiography and its complications

“…Cerebral air embolism is rare and may be prevented by attaching air filters to both the catheter and contrast-medium syringe, slowing the rate of contrast injection, reducing the number of microcatheter runs and ensuring appropriate catheter priming 20. Heparin-induced thrombocytopenia in patients exposed to heparin during several angiograms may also cause thromboembolism during angiography 21…”

Commentary: How to Deal With Air Released From Thoracic Endografts: Ignore It or Fear It?

“…It has also been described during lung biopsy, atrial ablation, deployment of septal occluders, and cardiopulmonary bypass surgery. 7,8 The reported incidence of symptomatic cerebral gas emboli during intra-arterial intervention is low (0.08%), 9 but such events may be underreported in atherosclerotic patients if incorrectly interpreted as solid thrombotic emboli.…”

“…Furthermore, diving medicine has shown that prompt hyperbaric oxygen treatment effectively reduces neurologic symptoms after gas embolism. 8 This maneuver could also be attempted in post-TEVAR stroke.…”

“…Post mortem studies have shown embolic air locks in cranial arteries and initiates proinflammatory cascades in the tissue. 8 There are lessons to be learned from diving medicine, where arterial gas embolization is a feared complication. 9 Air consists of 80% nitrogen that dissolves slowly in tissues.…”