Presumed Air by Vitrectomy Embolisation (PAVE) a potentially fatal syndrome

Abstract

BackgroundSince first being reported in the ophthalmology literature in 2010, three cases (one fatal) of suspected venous air embolism (VAE) during vitrectomy have received little notice, and the vitrectomy/VAE connection has been described as unproven. We investigated the ability of air to exit the eye through vortex veins after accidental suprachoroidal air infusion.MethodsVitrectomy was performed on four donor eyes. Unsutured cannulas were partially withdrawn during air fluid exchange, producing choroidal detachments that emulated accidental suprachoroidal air infusion from a slipping cannula. Eyes with and without clamping of the vortex vein stumps were partially submerged in a water bath.ResultsExtensive choroidal detachment was created in all eyes during air infusion. All eyes with open vortex veins demonstrated rapid air extravasation/bubbling. An eye with clamped vortex vein stumps showed no air extravasation until the clamps were removed.ConclusionsWhen combined with existing clinical reports of suspected VAE in the eyes of living patients during ocular air fluid exchange, this experiment justifies recognition of presumed air by vitrectomy embolisation (PAVE) as a rare but potentially fatal vitrectomy complication. Simple surgical precautions can change PAVE from a ‘rare event’ to a ‘never event’, beginning with acknowledgment of its existence.

Fatal air embolism and ocular shrinkage during vitrectomy

“…Morris et al [1] simulated suprachoroidal air infusion to create torn vortex vein stumps on four donors' eyes, and entrained air flew through the veins during ocular air/fluid exchange (OAFE). We present a lethal case of VAE confirmed by transesophageal echocardiography (TEE) and extracorporeal membrane oxygenation (ECMO) during vitrectomy for total choroidal detachment.…”

Percutaneous cardiopulmonary support to treat suspected venous air embolism with cardiac arrest during open eye surgery: a case report

“…Although rare, there have been previous reports of air embolism during open eye surgery using air-fluid exchange [ 2 , 3 , 4 , 5 , 6 ]. Concurrent ocular air-fluid exchange and VAE has been recently acknowledged as a potentially fatal event that all vitreoretinal surgeons should be aware of [ 7 ]. The initiating event in the case discussed here seems to be entrapment of air through abnormal venous access formed at the choroidal or vortex veins during removal of the tumor mass.…”

“…As air enters the eye, fluid in the vitreous cavity is removed either passively or with active suction [ 8 ]. The air flow against atmospheric pressure when using 40 mmHg infusion pressure through a 25-gauge cannula is known to be approximately 350 ml per minute [ 7 ], and this can be expected to be greater with a larger cannula and higher infusion pressure. The present case is similar to two previous case reports in which VAE occurred during vitrectomy for the removal of an intraocular foreign body [ 4 ].…”

Highlights from this issue

“…In an experimental post mortem study on human globes, Morris et al describe the possibility of an intrusion of air into the vortex veins if air gets access to the suprachoroidal space during vitrectomy 6. This mechanism could explain the development of fatal air embolizations in patients undergoing pars plana vitrectomy with fluid-air exchange.…”