Intermittent balloon occlusion to favor nidal penetration during embolization of arteriovenous malformations: a technique modification.

Endovascular embolization of brain arteriovenous malformations (AVMs) has improved with liquid occlusive agents, but flow-related and anatomic restrictions limit endovascular capabilities. AVM compartments supplied by leptomeningeal networks and feeding arteries too small and/or tortuous for safe catheterization are rarely penetrated by liquid occlusive agents. A case with both impediments prompted a novel solution. A balloon was inflated across the supply to a lenticulostriate feeder, thereby favoring penetration of the liquid occlusive agent, injected from a different feeding territory, back into the AVM compartment supplied by the temporarily occluded feeder. This technique may reduce the number of embolization stages in large high-flow AVMs and increase the likelihood of achieving complete occlusion. This technique is highly complex and requires meticulous monitoring of multiple events.

Pipeline embolization device: a new source for embolic retinal vascular occlusion.

A 57-year-old woman underwent treatment of a left internal carotid artery aneurysm with a Pipeline embolization device. She subsequently experienced multiple branch retinal artery occlusions in her left eye. Although rare, ophthalmic complications may follow this new technique in the treatment of intracranial aneurysms.

Intermittent balloon occlusion to favor nidal penetration during embolization of arteriovenous malformations: a technique modification.

Endovascular embolization of brain arteriovenous malformations (AVMs) has improved with liquid occlusive agents, but flow-related and anatomic restrictions limit endovascular capabilities. AVM compartments supplied by leptomeningeal networks and feeding arteries too small and/or tortuous for safe catheterization are rarely penetrated by liquid occlusive agents. A case with both impediments prompted a novel solution. A balloon was inflated across the supply to a lenticulostriate feeder, thereby favoring penetration of the liquid occlusive agent, injected from a different feeding territory, back into the AVM compartment supplied by the temporarily occluded feeder. This technique may reduce the number of embolization stages in large high-flow AVMs and increase the likelihood of achieving complete occlusion. This technique is highly complex and requires meticulous monitoring of multiple events.

Neurological sequelae from brachiocephalic vein stenosis.

Stenosis of central veins (brachiocephalic vein [BCV] and superior vena cava) occurs in 30% of hemodialysis patients, rarely producing intracranial pathology. The authors present the first cases of BCV stenosis causing perimesencephalic subarachnoid hemorrhage and myoclonic epilepsy. In the first case, a 73-year-old man on hemodialysis presented with headache and blurry vision, and was admitted with presumed idiopathic intracranial hypertension after negative CT studies and confirmatory lumbar puncture. The patient mildly improved until hospital Day 3, when he experienced a seizure; emergency CT scans showed perimesencephalic subarachnoid hemorrhage. Cerebral angiography failed to find any vascular abnormality, but demonstrated venous congestion. A fistulogram found left BCV occlusion with jugular reflux. The occlusion could not be reopened percutaneously and required open fistula ligation. Postoperatively, symptoms resolved and the patient remained intact at 7-month follow-up. In the second case, a 67-year-old woman on hemodialysis presented with right arm weakness and myoclonic jerks. Admission MRI revealed subcortical edema and a possible dural arteriovenous fistula. Cerebral angiography showed venous engorgement, but no vascular malformation. A fistulogram found left BCV stenosis with jugular reflux, which was immediately reversed with angioplasty and stent placement. Postprocedure the patient was seizure free, and her strength improved. Seven months later the patient presented in myoclonic status epilepticus, and a fistulogram revealed stent occlusion. Angioplasty successfully reopened the stent and she returned to baseline; she was seizure free at 4-month follow-up. Central venous stenosis is common with hemodialysis, but rarely presents with neurological findings. Prompt recognition and endovascular intervention can restore normal venous drainage and resolve symptoms.

Acute embolization of ruptured brain arteriovenous malformations.

BACKGROUND: Ruptured brain arteriovenous malformations (bAVMs) are at increased risk of re-hemorrhage but management has historically been conservative. This is because: (1) ruptured bAVMs have not been considered as catastrophic as ruptured cerebral aneurysms, (2) surgical resection is aided by waiting for brain edema to resolve and clot to liquefy and (3) fear exists that partially treated bAVMs may be more dangerous than those untreated. The purpose of this study was to determine the feasibility and safety of acute embolization in patients with ruptured bAVMs. METHODS: 21 consecutive patients who underwent acute embolization of ruptured bAVMs from 2007 to 2011 were retrospectively reviewed. All treatments consisted of embolization exclusively using Onyx liquid embolic agent. Neurological outcomes were assessed using the Glasgow Outcome Scale (GOS) at hospital discharge following initial treatment. RESULTS: Nine patients (43%) were male, mean age was 38 years (range 8-75) and initial embolization was performed at a median of 4 days after ictus (mean 5.8, range 0-19). Spetzler-Martin grades ranged from I to VI (mean 3, median 3). In seven patients (33%) the AVM was completely occluded with a single treatment. With subsequent embolizations, complete occlusion occurred in four additional patients (19%). Six patients (29%) had post-embolization AVM resection and one patient (5%) had post-embolization gamma knife irradiation. None has suffered subsequent hemorrhages (mean follow-up 7.5 months). The mean discharge GOS of all patients was 4.4 (range 1-5). CONCLUSION: Treatment of ruptured bAVMs is often delayed but our experience with Onyx suggests that acute embolization is safe and feasible.

Can a self-expanding aneurysm stent be clipped? Emergency proximal control options for the vascular neurosurgeon.

BACKGROUND: If a self-expanding stent has been placed during endovascular treatment of an aneurysm and subsequently an open aneurysm surgery becomes necessary in the same or an adjacent area, is it possible and safe to obtain proximal control by placing a temporary clip on the artery at a point where it contains the stent? OBJECTIVE: To evaluate the effect of temporary clip application to 3 separate stent systems in an in vitro flow model with the stated hypothesis that clip application to these stents will result in permanent stent deformation. METHODS: This is an in vitro flow model study using an accepted synthetic blood vessel substitute. The Neuroform(3) (Boston Scientific), Enterprise (Cordis/Codman), and Pipeline (ev3) stents were deployed within the flow model; temporary clips were applied; and angiographic measurements subsequently made. RESULTS: Two 4 × 30-mm Neuroform(3) stents, two 4.5 × 28-mm Enterprise stents, and two 3.75 × 20-mm Pipeline stents were successfully deployed and clipped repeatedly (4 iterations). Two- and 3-dimensional angiograms were obtained. After repeated clip occlusion, the Neuroform(3) and Enterprise stents returned to their original configuration and diameter. Clip application to both also resulted in immediate flow arrest. In contrast, initial clip application to the Pipeline stents did not result in flow arrest, but the second single clip application did. The Pipeline stents were also irreversibly deformed after the experimental protocol, with an average luminal diameter reduction of 26.85% (P < .05). CONCLUSION: The Neuroform(3) and Enterprise stents responded favorably to temporary clip application, returning to their original diameter after clip removal and showing no sign of permanent structural modification. The Pipeline flow-diverting stent, however, was irreversibly deformed by clip application. These data indicate that temporary clip application to certain stents is possible. Further in vivo study is required.

Treatment of third ventricular choroid plexus papilloma in an infant with embolization alone.

The authors present the case of a 3-month-old boy with a third ventricular tumor consistent with a choroid plexus papilloma. This child presented with macrocephaly, irritability, inability to roll over, and vomiting. He was found to have an enlarged head circumference, a full and tense fontanel, splayed sutures, and forced downward gaze. Imaging revealed severe ventriculomegaly and a brightly enhancing third ventricular lesion consistent with papilloma. Treatment planning included placement of a ventriculoperitoneal shunt to treat hydrocephalus and to allow the child to grow prior to resection. Due to the vascular nature of these tumors and the age of this child, the tumor was embolized with a plan for eventual resection; however, embolization resulted in involution and total regression of the tumor. There is no residual disease at last follow-up of 16 months. In this specific scenario of a choroid plexus papilloma in an infant, when operative intervention may be technically difficult and associated with significant morbidity, embolization with close observation may be a valid treatment option. If used, the patient would need to be closely followed for evidence of residual or recurrent disease, which would require operative intervention.

Glossopharyngeal schwannoma in childhood.

Glossopharyngeal (that is, cranial nerve IX) schwannomas are extremely rare nerve sheath tumors that frequently mimic the more common vestibular schwannoma in their clinical as well as radiographic presentation. Although rare in adults, this tumor has not been reported in a child. The authors report the case of a 10-year-old boy who presented with several months of unilateral hearing loss. He was found to have a large right cerebellopontine angle tumor. Given the boy's primary complaint of hearing loss and the appearance of the lesion on imaging, the tumor was initially believed to be a schwannoma of the vestibular nerve. It was found intraoperatively, however, to originate from the glossopharyngeal nerve. To the authors' knowledge, this is the first reported case of a glossopharyngeal schwannoma in a child.