Intravascular ultrasound (IVUS) generates high-resolution cross-sectional images and sagittal reconstructions of the vessel wall and lumen. As a result, this imaging modality can provide accurate measurements of the degree of vessel stenosis, allow the detection of intraluminal thrombus, and analyze the plaque composition. The IVUS modality is widely used in interventional cardiology, and its use in neurointerventions has gradually increased. With case examples, the authors illustrate the utility of IVUS as an adjunct to conventional angiography for a wide range of intracranial and extracranial neurointerventions.
Peter Kan, Maxim Mokin, Adib A. Abla, Jorge L. Eller, Travis M. Dumont, Elad I. Levy and Adnan H. Siddiqui
Maxim Mokin, Peter Kan, Tareq Kass-Hout, Adib A. Abla, Travis M. Dumont, Kenneth V. Snyder, L. Nelson Hopkins, Adnan H. Siddiqui and Elad I. Levy
Intracerebral hemorrhage (ICH) secondary to intravenous and intraarterial revascularization strategies for emergent treatment of acute ischemic stroke is associated with high mortality. ICH from systemic thrombolysis typically occurs within the first 24–36 hours of treatment initiation and is characterized by rapid hematoma development and growth. Pathophysiological mechanisms of revascularization therapy-induced ICH are complex and involve a combination of several distinct processes, including the direct effect of thrombolytic agents, disruption of the blood-brain barrier secondary to ischemia, and direct vessel damage from wire and microcatheter manipulations during endovascular procedures. Several definitions of ICH secondary to thrombolysis currently exist, depending on clinical or radiological characteristics used. Multiple studies have investigated clinical and laboratory risk factors associated with higher rates of ICH in this setting. Early ischemic changes seen on noncontrast CT scanning are strongly associated with higher rates of hemorrhage. Modern imaging techniques, particularly CT perfusion, provide rapid assessment of hemodynamic parameters of the brain. Specific patterns of CT perfusion maps can help identify patients who are likely to benefit from revascularization or to develop hemorrhagic complications. There are no established guidelines that describe management of revascularization therapy–induced ICH, and great variability in treatment protocols currently exist. General principles that apply to the management of spontaneous ICH might not be as effective for revascularization therapy–induced ICH. In this article, the authors review current knowledge of risk factors and radiological predictors of ICH secondary to stroke revascularization techniques and analyze medical and surgical management strategies for ICH in this setting.
Adnan H. Siddiqui, Adib A. Abla, Peter Kan, Travis M. Dumont, Shady Jahshan, Gavin W. Britz, L. Nelson Hopkins and Elad I. Levy
The use of flow-diverting stents has gained momentum as a curative approach in the treatment of complex proximal anterior circulation intracranial aneurysms. There have been some reported attempts of treating formidable lesions in the posterior circulation. Posterior circulation giant fusiform aneurysms have a particularly aggressive natural history. To date, no one approach has been shown to be comprehensively effective or low risk. The authors report the initial results, including the significant morbidity and mortality encountered, with flow diversion in the treatment of large or giant fusiform vertebrobasilar aneurysms at Millard Fillmore Gates Circle Hospital.
The authors retrospectively reviewed their prospectively collected endovascular database to identify patients with intracranial aneurysms who underwent treatment with flow-diverting devices and determined that 7 patients had presented with symptomatic large or giant fusiform vertebrobasilar aneurysms. The outcomes of these patients, based on the modified Rankin Scale (mRS), were tabulated, as were the complications experienced.
Among the 7 patients, Pipeline devices were placed in 6 patients and Silk devices in 1 patient. At the last follow-up evaluation, 4 patients had died (mRS score of 6), all of whom were treated with the Pipeline device. The other 3 patients had mRS scores of 5 (severe disability), 1, and 0. The deaths included posttreatment aneurysm ruptures in 2 patients and lack of improvement in neurological status related to presenting brainstem infarcts and subsequent withdrawal of care in the other 2 patients.
Whether flow diversion will be an effective strategy for treatment of large or giant fusiform vertebrobasilar aneurysms remains to be seen. The authors' initial experience suggests substantial morbidity and mortality associated with the treatment and with the natural history. As outcomes data slowly become available for patients receiving these devices for fusiform posterior circulation aneurysms, practitioners should use these devices judiciously.
Adib Adnan Abla, Aaron J. Clark and Michael T. Lawton
In this video, we illustrate a right far-lateral craniotomy for resection of a 13-mm cavernous malformation of the pons in a healthy 53-year-old female patient presenting with diplopia and right 6th nerve palsy. The cavernous malformation was surrounded by normal pons, but was within 1 mm of the pontomedullary sulcus. The lesion was exposed from below through a far lateral craniotomy and accessed through the vasoaccessory triangle, superior to olivary nucleus and 12th cranial nerve. The alternative retrosigmoid craniotomy would have involved significant transgression of the middle cerebellar peduncle. The patient had gross-total resection and some temporary increase in her abducens nerve palsy without any complication.
The video can be found here: http://youtu.be/f14RR3CHQkw.
Adib Adnan Abla, Dario J. Englot and Michael T. Lawton
In this operative video, we demonstrate the approach to a 10-mm distal left vertebral artery and proximal basilar artery blister aneurysm in a 62-year-old male presenting with subarachnoid hemorrhage. He initially underwent clipping of the ruptured ACoA aneurysm and two incidental right MCA aneurysms. Ten days later, the posterior circulation aneurysms were clipped through an extended retrosigmoid approach, working between cranial nerves 9–11 inferiorly and 7–8 superiorly. The vertebral artery was accessible from its dural entry site to the vertebrobasilar junction with the rostral limit of the exposure at the level of the tentorium. He underwent uneventful clipping of all aneurysms without postoperative morbidity.
The video can be found here: http://youtu.be/O0lF0gkFZxc.