Ziad A. Hage

Increased prevalence and rupture status of feeder vessel aneurysms in posterior fossa arteriovenous malformations

Background Posterior fossa arteriovenous malformations (AVMs) are considered to have a higher risk of poor outcome, as are AVMs with associated aneurysms. We postulated that posterior fossa malformations may be more prone to associated feeder vessel aneurysms, and to aneurysmal source of hemorrhage. Objective To examine the prevalence and hemorrhagic risk of posterior fossa AVM-associated feeder vessel aneurysms. Methods A retrospective review of AVMs was performed with attention paid to location and presence of aneurysms. The hemorrhage status and origin of the hemorrhage was also reviewed. Results 571 AVMs were analyzed. Of 90 posterior fossa AVMs, 34 (37.8%) had aneurysms (85% feeder vessel, 9% intranidal, 15% with both). Of the 481 supratentorial AVMs, 126 (26.2%) harbored aneurysms (65% feeder vessel, 29% intranidal, 6% both). The overall incidence of feeder aneurysms was higher in posterior fossa AVMs, which were evident in 34.4% of infratentorial AVMs compared to 18.5% of supratentorial malformations (p<0.01). The presence of intranidal aneurysms was similar in both groups (9.2% vs 8.8%). Feeder artery aneurysms were much more likely to be the source of hemorrhage in posterior fossa AVMs than in supratentorial AVMs (30% vs 7.6%, p<0.01). Conclusions Posterior fossa AVMs are more prone to developing associated aneurysms, specifically feeder vessel aneurysms. Feeder vessel aneurysms are more likely to be the source of hemorrhage in the posterior fossa. As such, they may be the most appropriate targets for initial and prompt control by embolization or surgery due to their elevated threat.

Novel imaging approaches to cerebrovascular disease

Imaging techniques available to the physician treating neurovascular disease have substantially grown over the past several decades. New techniques as well as advances in imaging modalities continuously develop and provide an extensive array of modalities to diagnose, characterize, and understand neurovascular pathology. Modern noninvasive neurovascular imaging is generally based on computed tomography (CT), magnetic resonance (MR) imaging, or nuclear imaging and includes CT angiography, CT perfusion, xenon-enhanced CT, single-photon emission CT, positron emission tomography, magnetic resonance angiography, MR perfusion, functional magnetic resonance imaging with global and regional blood oxygen level dependent imaging, and magnetic resonance angiography with the use of the noninvasive optional vessel analysis software (River Forest, Ill). In addition to a brief overview of the technique, this review article discusses the clinical indications, advantages, and disadvantages of each of those modalities.

Cerebral revascularization: State of the art

Over the last half century, there has been significant progress in both the technique and the thought process involved in surgical cerebral revascularization. In this article, we review the state-of-the-art practice in cerebral revascularization, which includes the use of novel technologies and decision making in surgical techniques, in preoperative planning, and in postoperative monitoring. We also discuss the importance of flow measurement, a technique that has evolved the practice of cerebral revascularization by allowing for improved patient selection, appropriate patient-specific choice of bypass grafts, verification of intraoperative bypass success, and noninvasive and reliable postoperative follow-up. Technical advances in performing anastomosis aimed at reducing occlusion times during anastomosis are also discussed. Cerebral revascularization has truly become a state-of-the-art discipline involving cutting edge technology and demonstrating promising results. Nonetheless, much work remains to be carried out to further validate these methodologies and their impact on patient outcomes.

Clipping of bilateral MCA aneurysms and a coiled ACOM aneurysm through a modified lateral supraorbital craniotomy

We showcase the microsurgical clipping of a left middle cerebral artery (MCA) aneurysm-(B) done through a modified right lateral supraorbital craniotomy, as well as clipping of a previously coiled anterior communicating (ACOM) artery aneurysm-(C) and a bilobed right MCA aneurysm-(A). Splitting of the right sylvian fissure is initially performed following which a subfrontal approach is used to expose and dissect the contralateral sylvian fissure. The left MCA aneurysm is identified and clipped. The ACOM aneurysm is then clipped following multiple clip repositioning based on flow measurements. The right MCA aneurysm is then identified and each lobe is clipped separately. The first picture showcased in this video is a side to side right and left ICA injection in AP projection. In this picture, (A) points to the bilobed right MCA aneurysm, (B) to the left middle cerebral artery (MCA) aneurysm, and (C) to the previously coiled anterior communicating (ACOM) artery aneurysm. The red dotted line shows that both MCA aneurysms lie within the same plane which makes it easier to clip both of them, through one small craniotomy. The video can be found here: http://youtu.be/4cQC7nHsL5I .

Extracranial aneurysms of the distal posterior inferior cerebellar artery: Resection and primary reanastomosis as the preferred management approach

Background: Extracranial aneurysms of the posterior inferior cerebellar artery (PICA) are rare, with only 22 reported cases in the English literature. For saccular extracranial distal PICA aneurysms not amenable to coiling, a surgically placed clip is not protected by the cranium postoperatively, and can be subject to movement in the mobile cervical region. Furthermore, fusiform or complex aneurysms cannot be clipped primarily. Resection and primary reanastomosis is a useful surgical approach not previously described for these extracranial lesions. Case Description: We report three cases of extracranially located distal PICA aneurysms successfully treated with this surgical strategy at our center. One patient harboring a broad necked saccular aneurysm originally underwent successful primary clipping of the aneurysm but sustained a second subarachnoid hemorrhage (SAH) on postoperative day 25 due to clip dislodgement from vigorous neck movement. The other two patients were found to have fusiform and complex aneurysms, respectively. All three patients were ultimately treated with resection and end-to-end PICA anastomosis, which successfully obliterated their aneurysms. Conclusions: Resection and primary reanastomosis of extracranial distal PICA aneurysms averts the risk of clip dislodgement due to neck movement and/or compression by soft tissues in the upper cervical region. It is a safe and efficacious technique, which we propose as the preferred management strategy for these rare vascular lesions.

Neuroimaging in the modern era.

N euroimaging combines multiple imaging modalities that allow the visualization and study of the structure, function, pharmacology, and pathophysiology of the nervous system. Over the last several decades, this field has seen remarkable developments, with the work by Dandy on ventriculography and pneumoencephalography in 1918 and 1919, the introduction of cerebral angiography in 1927 by Egas Moniz, the introduction of computerized axial tomography by Cormack and Hounsfield in the early 1970s for which they won the 1979 Nobel Prize for Physiology or Medicine, and around that same time the introduction of magnetic resonance imaging (MRI) by Mansfield and Lauterbur for which they won the 2003 Nobel Prize for Physiology or Medicine. After these groundbreaking discoveries, continued technological and software developments allowed for the advent of computed tomography angiography, magnetic resonance angiography (MRA), functional MRI, and magnetoencephalography, among other techniques, further expanding the array of medical applications covered. Cerebrovascular disease and other disease entities such as Alzheimer’s and Parkinson’s can now be studied noninvasively in-depth. Cerebrovascular disease has a major impact on patients worldwide and is one of the main arenas where neuroimaging has flourished. Modern noninvasive neurovascular imaging encompasses computed tomography, magnetic resonance imaging, and nuclear imaging– based techniques. These modalities are critical when evaluating the cerebral vasculature and provide important data during workup of cerebral aneurysms and other vascular lesions, during workup of acute or chronic

Spinal epidural abscess in a patient with piriformis pyomyositis

Background: Spinal epidural abscess resulting from piriformis pyomyositis is extremely rare. Such condition can result in serious morbidity and mortality if not addressed in a timely manner. Case Description: The authors describe the case of a 19-year-old male presenting with a 2-week history of fever, low back pain, and nuchal rigidity. When found to have radiographic evidence of a right piriformis pyomyositis, he was transferred to our institution for further evaluation. Because he demonstrated rapid deterioration, cervical, thoracic, and lumbar magnetic resonance imaging scans were emergently performed. They revealed an extensive posterior spinal epidural abscess causing symptomatic spinal cord compression extending from C2 to the sacrum. He underwent emergent decompression and abscess evacuation through a dorsal midline approach. Postoperatively, he markedly improved. Upon discharge, the patient regained 5/5 strength in both upper and lower extremities. Cultures from the epidural abscess grew methicillin-sensitive Staphylococcus aureus warranting a 6-week course of intravenous nafcillin. Conclusion: A 19-year-old male presented with a holospinal epidural abscess (C2 to sacrum) originating from piriformis pyomyositis. The multilevel cord abscess was emergently decompressed, leading to a marked restoration of neurological function.

Cerebrospinal Fluid Leak Presenting as Epiphora.

A 52-year-old woman underwent a right frontotemporal craniotomy for microsurgical clip obliteration of a ruptured right dorsal variant ophthalmic segment carotid aneurysm. During the craniotomy, a defect involving the orbital roof was inadvertently created. The patient was noted postoperatively to have fluid egressing from her OD. The fluid was analyzed and based on glucose and chloride levels was determined to be cerebrospinal fluid (CSF). CT scan of the head demonstrated the orbital roof defect created during surgery. After placement of a lumbar drain, fluid egress from the eye significantly decreased, further confirming the suspicion for CSF leak. Patient was found to have a conjunctival defect of the OD, approximately 2.5 cm × 1.5 cm, extending to the fornix from 9 to 12 o’clock. The conjunctival defect and fornix were repaired with an amniotic membrane graft and a temporary tarsorrhaphy with subsequent resolution of CSF egress. The case report is in compliance with the Health Insurance Portability and Accountability Act.

Clipping of a ruptured anterior communicating artery aneurysm with right A1–A2 sectioning and reanastomosis

We showcase the microsurgical clipping of a previously coiled and ruptured anterior communicating artery aneurysm, done through a right-sided approach. Initial clipping with a fenestrated clip occluded the flow in the right A2. After temporary clipping of both A1 and A2 vessels, we cut the right A1 and A2, clipped the aneurysm with a straight clip while preserving the flow in the left A1 and A2 and then performed reanastomosis of the right A1-A2 in an end to end fashion. This strategy allowed for complete obliteration of the aneurysm while preserving the flow in all four vessels. The video can be found here: http://youtu.be/4Y024zU5NVo.

E-041 use of balloon angioplasty for pipeline stent foreshortening and improved apposition

Introduction The pipeline embolization device-(PED) has gained popularity in the treatment of cerebral aneurysms in selected patients, with studies evaluating its efficacy and safety showing promising results. Nonetheless, difficulty persists with deployment in tortuous vasculature, with less than ideal stent positioning, stent stretching, and poor stent/arterial wall apposition encountered in such instances. We report our experience with balloon angioplasty in reducing stent stretching, improving stent/arterial wall apposition, and aiding in stent repositioning. Methods A retrospective medical record, angiographic and video review of all pipeline cases done at the University of Illinois was performed, and cases where balloon angioplasty was utilized were selected. Vessel tortuosity was classified according to the published method by Lin et al . 1 Results A total of 6 patients were identified. All had pipeline stent deployment in the cavernous/paraclinoid segment of the ICA. We found (3) type-IV, (2) type-III, and 1 type-II ICA as classified by Lin et al . 1 Indications for balloon angioplasty were incomplete stent apposition in 5 cases, and poor stent position in 1 case. A balloon was successfully used in all 6 cases, improving stent/arterial wall apposition. In all cases, a Transform balloon was used over exchange wire to maintain endoluminal access. Additionally, proximal stent stretching was observed in two of the six cases, and successfully reduced with the balloon, resulting in improved positioning and apposition of the stent. Four patients have had follow-up angiogram at 6 months, none of which showed in-stent stenosis. Conclusions Tortuous ICA vasculature can increase the risk of stent stretching, incomplete stent/arterial wall apposition, and poor stent positioning. Balloon angioplasty is a safe and effective method to circumvent these challenges, and should be considered as a viable option in these cases. Reference Lin LM, Colby GP, Jiang B, et al . Classification of cavernous-ICA tortuosity: a predictor of procedural-complexity in Pipeline-embolization. J Neurointerv Surg. 2014 Disclosures Z. Hage: None. A. Alaraj: None. V. Aletich: None.