Balloon Test Occlusion

balloon test occlusion

This patient presented with recurrent meningioma involving the middle cranial fossa, cavernous sinus and infratemporal fossa. Repeat excision with possible sacrifice of the right internal carotid artery was considered.
A balloon test occlusion was performed. This procedure involves inflating a balloon in the internal carotid artery (open arrow), while performing tests of neurological function, arterial pressure both systemic and distal to the balloon, and contralateral cerebral angiography to determine collateral flow (eg from posterior communicating or anterior communicating arteries). If the patient passes these tests, a systemic hypotensive challenge is performed. The results of BTO correllate well with outcome after carotid artery sacrifice.
In this case, the patient passed the test neurologically (no deficit was induced), despite no evidence of collateral flow from either the contralateral internal carotid artery or the posterior circulation. The stump pressure (blood pressure distal to the balloon) was less than 2/3 of systemic pressure – indicating a physiological fail.
The reason for the patient’s preserved neurological function only became clear when the right external carotid artery (small arrow) was injected. There were collateral vessels supplying the distal internal carotid (small arrowhead). This was an important finding, as sacrifice of the internal carotid distal to the ECA collaterals would almost certainly have been disastrous.
The primary indications for temporary or permanent balloon occlusion are: surgically or endovascularly untreatable aneurysms; head & neck cancer where carotid or vertebral artery sacrifice is required; control of haemorrhage in trauma or cancer; arteriovenous fistulae (not otherwise treatable); and assessment prior to sacrifice of an injured (eg dissected) vessel. BTO is not without complications, with a permanent neurologic deficit rate of 0.4%. Even with a “pass” on BTO, there may still be neurological deficit after vessel sacrifice, in around 5% of cases.

Reference: Parkinson RJ, et al. Temporary and Permanent Occlusion of Cervical and Cerebral Arteries. Neurosurg Clin N Am 16 (2005) 249-256

Credit: Dr Jason Wenderoth

Credit: Dr Laughlin Dawes