Intracisternal Irrigation of Papaverine Leading to Choroidal Infarction

Papaverine hydrochloride, a potent vasodilator whose mechanism of action is thought to arise from inhibition of cyclic adenosine monophosphate and cyclic guanosine monophosphate phosphodiesterases in smooth muscle, is the most researched pharmacologic agent for the treatment of cerebral vasospasm. The successful use of intracranial irrigation of papaverine by neurosurgeons to prevent vasospasm after clipping of a cerebral aneurysm has been demonstrated, leading to its widespread use.¹ Although it is gaining popularity, its ocular complications still remain unclear. Transient cranial nerve palsies have been documented after papaverine irrigation. These cranial nerve abnormalities include facial nerve palsy and ipsilateral, bilateral, and contralateral pupillary dilation.^2,3 One case of unexplained transient monocular blindness has been reported.¹ We report a new concern of choroidal infarction causing permanent vision loss after intracranial irrigation with papaverine.

A 55-year-old woman with no visual symptoms visited our medical center with an 8-mm left middle cerebral artery aneurysm. The neurosurgical team performed surgical clipping of the aneurysm and intracranial irrigation with 3 mL of papaverine hydrochloride (30 mg/mL) to prevent postoperative vasospasm. The middle cerebral artery was accessed via a transfrontal approach whereby the neurosurgical team created a small keyhole in the sphenoid bone. The following day, the patient's visual acuity was no light perception, she had proptosis, and she had a frozen globe. Fundus examination results were initially unremarkable. Orbital computed tomography revealed left orbital swelling. Two days postoperatively her proptosis resolved spontaneously, although her visual acuity remained no light perception. When stable 1 week postoperatively, fundus photography of her left eye revealed arteriolar narrowing and diffuse areas of retinal pigment epithelial hyperpigmentation and atrophy, which was more pronounced in the macula (Figure 1). Fluorescein angiography revealed delayed retinal filling and areas of hyperfluorescence and hypofluorescence that correlated with the findings seen on color photography (Figure 2). Her visual acuity loss and fundus findings were attributed to choroidal infarction that occurred immediately postoperatively. A cerebral internal carotid artery angiogram performed 4 days postoperatively, once her proptosis resolved, revealed a surgical clip at the expected location and no evidence of a clip or obstruction at the level of the ophthalmic artery, suggesting choroidal reperfusion. Her visual acuity remained no light perception.

Papaverine is a potent vasodilator used to prevent cerebral vasospasm in cranial surgery. It has been shown to increase vessel diameter by an average of 30.1%.⁴ We believe our patient had a choroidal infarct, which is a previously unrecognized complication of intracranial papaverine irrigation.

Because of its potent vasodilatory effects, papaverine infusions have been shown to increase cerebral blood volume and create a rapid increase in intracranial pressure.⁵ Similarly, we feel that the exposure of our patient's orbital vessels to this agent may have led to widespread vasodilation, exudation, and an increase in orbital pressure, thereby compressing the posterior ciliary arteries. The small keyhole created in the sphenoid bone may have provided a conduit whereby intracranial papaverine gained access to the orbit. The spontaneous orbital decompression and choroidal reperfusion seen on fluorescein angiography a few days postoperatively may be explained by the short half-life of papaverine and suggest that orbital hemorrhage was not the culprit.⁶

Choroidal infarction after clipping of a cerebral aneurysm may occur after inadvertent clipping of or trauma to the ophthalmic artery. The observation in our case, with angiographic evidence of a patent ophthalmic artery, suggests that intracranial instillation of papaverine may lead to a choroidal infarct and irreversible vision loss. Although there may be spontaneous resolution of orbital edema, we should counsel neurosurgeons regarding this devastating ocular complication and have them consider other, less potent vasodilators when an aneurysm is accessed via the orbital wall.

Correspondence: Dr Reddy, Department of Ophthalmology, New York University Medical Center, 550 First Ave, New York, NY 10016 (reddys02@gmail.com).

Financial Disclosure: None reported.