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To describe seizure outcome and complications in patients with cavernous malformations (CM) undergoing early versus late surgery.A database was created for all CM patients who presented with seizure referred to the neurosurgical clinic at an academic center. A telephone survey and chart review were conducted to evaluate for preoperative and postoperative seizure frequency. Postoperative seizure-free outcome of patients who had ≤2 preoperative seizures versus those that had2 preoperative seizures was compared.A total of 35 CM patients were included for analysis. Nineteen patients had ≤2 preoperative seizures and 16 patients had2 preoperative seizures, six of them drug resistant for over two years. Among the ≤2 seizure group, 15 had only a single seizure before surgical resection. 94.7% of patients with ≤2 preoperative seizures and 62.5% of patients with2 preoperative seizures were seizure free one year following surgical resection (p = 0.019). 78.9% of patients with ≤2 preoperative seizures and 25% of patients with2 preoperative seizures were able to wean off AEDs (p 0.001). Among those patients who had a single preoperative seizure, 100% of patients were seizure free at one year.Early surgical resection for CM patients who present after a CM-related seizure is an effective, well tolerated treatment and has good chance to offer seizure freedom without the need for long-term antiepileptic medications. Outcome for patients operated with only one or two preoperative seizures may lead to better results than patients who delay the procedure.

BACKGROUND: Despite initial treatment with high-dose methotrexate-based regimens, many patients with primary central nervous system lymphoma (PCNSL) relapse and die from their disease. No standard of care exists at progression or relapse, but chemotherapy and in some cases radiation are usually used. Pemetrexed is a multitargeted antifolate, similar to methotrexate, but with a broader spectrum of activity. Because methotrexate is an integral part of PCSNL treatment, the authors assessed the antitumor activity and safety of pemetrexed in recurrent PCNSL. METHODS: Patients with relapsed/refractory PCNSL were enrolled in this trial. Treatment consisted of pemetrexed 900 mg/m2 given every 3 weeks with low-dose dexamethasone, folate, and B12 supplementation. Each cycle was 6 weeks, and follow-up imaging was done before each new cycle. Treatment was continued until complete remission, progression, or toxicity. RESULTS: Eleven patients were treated, with a median age of 69.8 years and Karnofsky performance status of 70%; 10 of 11 patients had failed prior high-dose methotrexate. The median number of pemetrexed cycles given was 5, with an associated overall response rate of 55% and disease control rate of 91%. The 6-month progression-free survival (PFS) was 45%, median PFS was 5.7 months, and median overall survival was 10.1 months. Toxicities were primarily hematologic and infectious. CONCLUSIONS: Pemetrexed has single-agent activity in relapsed/refractory PCNSL. Toxicities were seen likely because of the higher than standard dose used. Further investigation of this agent or other multitargeted antifolates in PCNSL is warranted to determine optimal dose and efficacy in a more homogeneous population. Cancer 2012. © 2011 American Cancer Society.

In this pilot study, we have derived an imaging metric (hyperperfusion volume) that reflects local perfusion changes in glioblastomas and have found that this metric has significantly improved correlation to time to progression as compared with more commonly used metrics.

Complications of tonsillar herniation associated with lumbar drainage have been reported in the literature. However, acutely symptomatic tonsillar herniation after intraoperative lumbar drainage is rare. The following case illustrates the risk associated with cerebrospinal fluid (CSF) drainage in the setting of tonsillar herniation. The use of lumbar drainage during cranial surgery is a common practice for reducing intracranial pressure and enhancing exposure, but is not without complications. In addition to the complications of the insertion procedure itself, the change in pressure gradient between the intracranial and the suboccipital compartments is of key importance. The authors present the case of a patient who underwent a subtemporal craniotomy for resection of mesial temporal cavernous malformation with intraoperative lumbar drainage. The patient had a preexisting, asymptomatic 4-mm Chiari malformation and progressive neurological deficits resulting from further cerebellar tonsillar herniation in the early postoperative period developed, which required a lumbar blood patch, decompressive suboccipital craniectomy, and C-1 laminectomy with duroplasty. After placement of the lumbar drain and subsequent CSF drainage, the change in CSF pressure gradient above and below the foramen magnum probably led to the herniation. Unfortunately, the patient has lasting neuropathic pain and cervical cord signal changes on MR images.

The goals of microsurgical and endovascular treatment of intracranial aneurysms are to prevent subarachnoid hemorrhage and/or eliminate mass effect symptoms. Debate has raged regarding which aneurysms to treat and with which technique or combination of techniques. It is our impression that studies that have assessed aneurysm natural history and treatment options are compromised by the inherent limitations of clinical trials, with many natural history studies likely underestimating rupture risk over long-term follow-up. Endovascular therapy and open neurosurgery should both be used strategically, and our current interest is in integrating these techniques in a fashion extending beyond the simplistic clip-versus-coil debate.

Presenting symptoms of aneurysmal subarachnoid hemorrhage (SAH) and reversible cerebral vasoconstriction syndrome (RCVS) may overlap. Patients with RCVS often harbor unruptured aneurysms. We report a case of RCVS in a patient with an unruptured intracranial aneurysm. The development of diffuse vasoconstriction after aneursym clipping in the absence of any subarachnoid blood was initially confusing, until subtle vasoconstriction before clipping was seen retrospectively.We obtained perfusion and diffusion MRI studies on this patient, which shed light on the pathophysiology of RCVS.It is important for physicians who care for patients with aneurysmal SAH to recognize RCVS, as the treatments for these two conditions are different.

Spontaneous ICH remains a formidable disease that continues to disable and kill the majority of its victims. Treatment of the disease continues to be controversial and without any proved success, such as improvement in the disease mortality or the resulting disability in survivors. Primary prevention is the most effective medical intervention. Nevertheless, as the population continues to age and patients remain undertreated for hypertension, the incidence of ICH likely will increase, resulting in significant socioeconomic impact on society in the coming years. It is imperative that more research be conducted to improve treatment and outcomes of patients who have ICH. Unlike ischemic stokes or other causes of hemorrhagic stroke, such as SAH, where major advancement of treatment has led to improved outcomes, the increased incidence of ICH has not been matched with any considerable improvement in treatment. This burden to improve therapeutic interventions for patients who have ICH should be shared by all neurosurgeons, stroke neurologists, and critical care physicians who care for these patients on a regular basis. It is hoped that early diagnosis and resuscitation, prevention of hematoma growth, selective surgery or minimally invasive clot evacuation, and judicious critical care and rehabilitation will combine to lessen the burden of this disease.

Successful microsurgical resection of an infratentorial arteriovenous malformation (AVM) requires both surgical skill and intraoperative judgment. Extensive practical experience in treating these complex lesions, which is acquired over many years, is of substantial value during each new operation. The authors present the surgical approaches and techniques used for the treatment of posterior fossa AVMs based largely on the strategies acquired and developed by the senior author (H.H.B.). Emphasis is placed on conceptual principles of AVM excision, as well as principles incorporated for the treatment of each specific type of infratentorial malformation.

Microsurgical clip reconstruction of a giant basilar artery aneurysm is considered one of the most challenging operative endeavors in neurosurgical practice. The operation, when carried out successfully, requires both surgical skill and intraoperative judgment. The authors present the surgical approaches and techniques used for the treatment of giant basilar artery aneurysms. In particular, the authors emphasize the extended lateral transsylvian approach, an exposure developed by the senior author (H.H.B.). In addition, this paper details the methods of preoperative evaluation, skull base approaches, proximal occlusive techniques, and the use of cerebral revascularization strategies as an adjunct in aneurysm obliteration.

The authors present the case report of a pediatric patient with a ruptured traumatic pseudoaneurysm of the intracranial vertebral artery (VA) from which the posterior inferior cerebellar artery (PICA) emerged. After considering multiple therapeutic options, the patient was treated surgically by trapping of the aneurysm segment and direct reimplantation of the PICA distal to the rupture site. In addition to presenting this unique case, the authors discuss the treatment of VA pseudoaneurysms and the various techniques for PICA revascularization. A review of the literature on PICA reimplantation is provided as an adjunct in the treatment of complex VA aneurysms.

The surgical treatment of dural arteriovenous fistulas at the beginning of the 21st century remains a cornerstone of treatment of these difficult lesions. The rapid advancement of endovascular treatments has allowed combined strategies with endovascular and surgical treatments to successfully treat previously untreatable lesions with minimal morbidity and mortality. There are also dural arteriovenous fistula types which remain preferentially treatable with surgery, and surgical expertise in this area remains an essential component of any treatment team. Advances in the surgical treatment of these lesions are based also on a better understanding of the natural history of these lesions, which dictates the importance of definitive treatment if at all possible. Modern imaging has also significantly advanced our understanding of these complex lesions.

Isolated dissections of the posterior inferior cerebellar artery (PICA) are rare. Thus, no large series of cases have been reported in the literature. Due to limited knowledge regarding the natural history of these lesions and the lack of high-quality evidence supporting various treatment options, management is controversial and practice parameters are ill defined. In order to offer a comprehensive reference for the diagnosis and management of isolated PICA dissections, the authors reviewed the National Library of Medicine from 1966 to October 2001. Twenty-seven patients averaging 43.6 years of age and including 14 males and 13 females were reported. Subarachnoid hemorrhage occurred in 20 patients, and two died. Dissections were located in the proximal PICA in 22 patients and were three times more common on the left side (left:right=3:1). Six patients were managed conservatively, and four with endovascular techniques. Seventeen had open surgery: five underwent resection, two went through trapping, and two had proximal clipping. Wrapping with muscle was performed in two patients, encasement with Sundt clips in two, and four had occipital artery (OA)-PICA bypass surgery. A meticulous analysis of reported cases with regard to clinical and pathological features, management strategies, and outcomes is presented.

OBJECTIVE AND IMPORTANCE: We present the case of a patient who experienced bilateral middle cerebral artery infarctions after Hunterian ligation and trapping of a ruptured right cavernous aneurysm, despite a high-flow extracranial-intracranial bypass. This is a rare complication, and it highlights the need for further refinements in our understanding of the hemodynamic insufficiency created by major vessel sacrifice. CLINICAL PRESENTATION: The patient was a 59-year-old woman who experienced multiple episodes of massive epistaxis before undergoing angiography, which revealed left internal carotid artery occlusion and an irregular right cavernous aneurysm. The patient was then transferred to our center for treatment. The patient was neurologically intact at presentation, and her epistaxis was controlled by nasal packing. INTERVENTION: The patient underwent an extracranial-intracranial bypass from the external carotid artery to the M2 segment of the right middle cerebral artery, followed by trapping of the aneurysm. Despite evidence of graft patency, the patient experienced bilateral middle cerebral artery distribution infarctions after surgery. CONCLUSION: Although extracranial-intracranial bypasses protect the majority of patients who undergo carotid artery ligation from ischemic complications, this case demonstrates that hemodynamic insufficiency can occur even with a high-flow saphenous vein graft. Better ways to quantitate the hemodynamic needs of the brain after major vessel sacrifice may facilitate matching of the revascularization strategy to the specific needs of each patient, thus further reducing the likelihood of ischemic complications.

The unexpected rupture of an intracranial aneurysm is a potentially catastrophic event. Strategies to control intraoperative aneurysm hemorrhage are based on sound surgical principles and take into consideration such variables as the timing, location, and severity of the rupture. Proven, successful techniques to prevent or control complications during aneurysm surgery are discussed in this article.

Subarachnoid hemorrhage is a formidable and common health care problem. Early diagnosis and management are crucial to reduce the morbidity form this complex and multifaceted disease. Open surgery and endovascular techniques both aim at eliminating the source of hemorrhage. The choice of therapy can be made rationally based on an understanding of the merits, risks, and limitations of each therapy. The care of pregnant patients with subarachnoid hemorrhage and patients who harbor both aneurysms and AVMs can be approached rationally with an understanding of the complex pathophysiology behind these clinical scenarios. Familiarity with the signs of mild SAH, and advances in familial screening, noninvasive imaging, and therapies for vasospasm will continue to lessen the toll of this dramatic illness on the public well-being.

Invasive hemodynamic monitoring has become standard in the management of aneurysmal subarachnoid hemorrhage. This study is a retrospective analysis of 630 Swan-Ganz catheters placed in 184 patients with aneurysmal subarachnoid hemorrhage. Evaluation of complications demonstrated a 13% incidence of catheter-related sepsis (81 of 630 catheters), a 2% incidence of congestive heart failure (13 of 630 catheters), a 1.3% incidence of subclavian vein thrombosis (8 of 630 catheters), a 1% incidence of pneumothorax (6 of 630 catheters), and a 0% incidence of pulmonary artery rupture. In the management of patients with aneurysmal subarachnoid hemorrhage, invasive hemodynamic monitoring continues to be an important tool with acceptable complications.

BACKGROUND In July 2009, the Accreditation Council for Graduate Medical Education (ACGME) incorporated postgraduate year 1 (PGY1 intern) level training into all U.S. neurosurgery residency programs. OBJECTIVE To provide a fundamentals curriculum for all incoming neurosurgery PGY1 residents in ACGME-accredited programs, including skills, knowledge, and attitudes that promote quality, patient safety, and professionalism. METHODS The Society of Neurological Surgeons organized 6 regional "boot camp" courses for incoming neurosurgery PGY1 residents in July 2010 that consisted of 9 lectures on clinical and nonclinical competencies plus 10 procedural and 6 surgical skills stations. Resident and faculty participants were surveyed to assess knowledge and course effectiveness. RESULTS A total of 186 of 197 U.S. neurosurgical PGY1 residents (94%) and 75 neurosurgical faculty from 36 of 99 programs (36%) participated in the inaugural boot camp courses. All residents and 83% of faculty participants completed course surveys. All resident and faculty respondents thought that the boot camp courses fulfilled their purpose and objectives and imparted skills and knowledge that would improve patient care. PGY1 residents' knowledge of information taught in the courses improved significantly in postcourse testing (P < .0001). Residents and faculty particularly valued simulated and other hands-on skills training. CONCLUSION Regional organization facilitated an unprecedented degree of participation in a national fundamental skills program for entering neurosurgery residents. One hundred percent of resident and faculty respondents positively reviewed the courses. The boot camp courses may provide a model for enhanced learning, professionalism, and safety at the inception of training in other procedural specialties.

Trigeminal pain is described as sudden, severe, unilateral, brief, recurrent episodes of sharp shooting pain in the distribution of one or more of the trigeminal branches. The incidence is 5 in 100,000. Pain can be a sequel to normal stimuli such as eating or shaving. This pain is thought to be related to nerve compression by an artery or vein at the nerve dorsal root entry zone. In theory, the compression produces demyelination of nerve fibers, which can affect transmission, processing, and interpretation of impulses. The entry zone was first observed by Dandy in 1929. Later, NM Dott proposed demyelination at the entry zone as the cause of pain which Gardner described as a short circuit of afferent stimuli. In addition, King suggested a central mechanism for pain in the trigeminal distribution and Jannetta promoted microvascular decompression (MVD) as an effective treatment [1]. Left untreated, the patient with trigeminal neuralgia proceeds to have shorter intervals free of pain and may progress to have another more complicated type 2 pain syndrome. Patients who fail medical management either because of pain control or excessive side effects are candidates for surgical treatment. An extensive radiological exam may include reliable 3D high-resolution magnetic resonance imaging (MRI) with constructive interference in steady state (CISS) or fast imaging employing steady state acquisition sequence (FIESTA) that can identify the location and degree of compression at the entry zone. The clinical diagnosis combined with this expanded radiological exam will lead to better preoperative planning and an improved surgical outcome [2, 3].

BACKGROUND: We report an unusual case of a true dural aneurysm arising from the posterior meningeal artery that fed a symptomatic dural arteriovenous fistula located at the right transverse-sigmoid sinus junction. CLINICAL PRESENTATION: A 29-year-old right-handed white woman presented with aneurysmal dilatation of hypertrophied posterior meningeal artery feeding a partially treated dural arteriovenous fistula. INTERVENTION: The aneurysm, which measured approximately 3 mm in width and 5 mm in length, was located in the intracranial space with a thin-walled dome projecting toward the cerebellum. Its afferent and efferent vessels were identified, secured, and the lesion was excised en bloc. CONCLUSION: A thorough evaluation of all diagnostic studies should be performed for patients with vascular malformations to help identify these or other unusual lesions that may aid in the risk stratification process and management plan.

Arteriovenous malformations (AVMs) of the posterior fossa are complex neurovascular lesions that are less common than their supratentorial counterparts, accounting for < 15% of all AVMs. The majority of patients with these lesions present with intracranial hemorrhage, a factor that has been consistently shown to increase one's risk for subsequent bleeding. Studies have additionally shown a posterior fossa or deep AVM location to portend a more aggressive natural history. The authors reviewed the literature on posterior fossa AVMs, finding their annual rupture rates to be as high as 11.6%, an important factor that underscores the importance of aggressive treatment of lesions amenable to intervention as therapeutic options and results continue to improve.

Sufficient temporal resolution is required to image the dynamics of blood flow, which may be critical for accurate diagnosis and treatment of various intracranial vascular diseases, such as arteriovenous malformations (AVMs) and aneurysms. Highly-constrained projection reconstruction (HYPR) has recently become a technique of interest for high-speed contrast-enhanced magnetic resonance angiography (CE-MRA). HYPR provides high frame rates by preferential weighting of radial projections while maintaining signal-to-noise ratio (SNR) by using a high SNR composite. An analysis was done to quantify the effects of HYPR on SNR, contrast-to-noise ratio (CNR), and temporal blur compared to the previously developed radial sliding-window technique using standard filtered backprojection or regridding methods. Computer simulations were performed to study the effects of HYPR processing on image error and the temporal information. Additionally, in vivo imaging was done on patients with angiographically confirmed AVMs to measure the effects of alteration of various HYPR parameters on SNR as well as the fidelity of the temporal information. The images were scored by an interventional radiologist in a blinded read and were compared with X-ray digital subtraction angiography (DSA). It was found that with the right choice of parameters, modest improvements in both SNR and dynamic information can be achieved as compared to radial sliding-window MRA.

Background and Purpose— The pathogenesis of intracranial aneurysms (IAs) remains elusive. Most studies have focused on individual genes, or a few interrelated genes or products, at a time in human IA. However, a broad view of pathologic mechanisms has not been investigated by identifying pathogenic genes and their interaction in networks. Our study aimed to analyze global gene expression patterns in the IA wall. Methods— To our knowledge, our group was the first to perform Illumina microarray analysis on human IA via comparison of aneurysm wall and superficial temporal artery tissues from 6 consecutive patients. We adopted stringent statistical criteria to the individual genes; genes with a false discovery rate 2-fold change were selected as differentially expressed. To identify the overrepresented biologic pathways with the differentially expressed genes, we performed hypergeometric testing of the genes selected by relaxed criteria of P 1.5. Results— There are 326 distinct differentially expressed genes between IA and superficial temporal artery tissues (>2-fold change) with a false discovery rate Conclusions— The differentially expressed genes in the aneurysm wall may shed light on aneurysm pathobiology and provide novel targets for therapeutic intervention. These data will help generate hypotheses for future studies.

Objective and importance We present the second report in the literature on the use of low-flow hypothermic cardiopulmonary bypass to aide in the surgical resection of a large intraparenchymal arteriovenous fistula. Clinical presentation The patient was a 46-year-old man who was found to have a left sylvian arteriovenous fistula with a giant varix during a workup for chronic left frontal headaches and was referred to our center for management. A cardiac workup revealed a cardiac output of 9 L per minute. Intervention Endovascular embolization of the lesion was initially attempted without success because of the high flow within the lesion and the large diameter of the feeding arteries. We then planned combined and staged endovascular and surgical approaches to gradually eliminate the fistula. Endovascular embolization, both transarterial and transvenous, could not be performed because of the high flow in the fistula. Despite the stepwise reduction of flow during the course of several weeks via surgical exposures and arterial ligations, the fistula remained difficult to remove because of its size and the turgor of the varix. Once hypothermic low-flow circulatory bypass was used, however, decompression of the sac allowed access to the afferent vasculature. Conclusion The use of low-flow hypothermic circulatory bypass can facilitate the surgical extirpation of certain large intraparenchymal arteriovenous fistulas.

Complications of tonsillar herniation associated with lumbar drainage have been reported in the literature. However, acutely symptomatic tonsillar herniation after intraoperative lumbar drainage is rare. The following case illustrates the risk associated with cerebrospinal fluid (CSF) drainage in the setting of tonsillar herniation. The use of lumbar drainage during cranial surgery is a common practice for reducing intracranial pressure and enhancing exposure, but is not without complications. In addition to the complications of the insertion procedure itself, the change in pressure gradient between the intracranial and the suboccipital compartments is of key importance. The authors present the case of a patient who underwent a subtemporal craniotomy for resection of mesial temporal cavernous malformation with intraoperative lumbar drainage. The patient had a preexisting, asymptomatic 4-mm Chiari malformation and progressive neurological deficits resulting from further cerebellar tonsillar herniation in the early postoperative period developed, which required a lumbar blood patch, decompressive suboccipital craniectomy, and C-1 laminectomy with duroplasty. After placement of the lumbar drain and subsequent CSF drainage, the change in CSF pressure gradient above and below the foramen magnum probably led to the herniation. Unfortunately, the patient has lasting neuropathic pain and cervical cord signal changes on MR images.

Objective Arteriovenous malformations of the basal ganglia and thalamus are often managed with radiosurgery or observation, without consideration of microsurgery. Given the devastating effects of hemorrhage from these lesions, the accumulating evidence that they bleed more frequently than their lobar counterparts should prompt more creative thinking regarding their management. Methods A review of the endovascular, microsurgical, and radiosurgical literature for arteriovenous malformations of the basal ganglia and thalamus was performed, with close attention to surgical approaches, obliteration rates, and procedure-related complications. Results A complete resection rate of 91% and a mortality rate of 2.4% were found across surgical series of these lesions. These contrast with a 69% rate of complete obliteration and a 5.3% mortality rate (from latency-period hemorrhage) found when compiling results across the radiosurgical literature. Conclusion Given an appropriate surgical corridor of access, often afforded by incident hemorrhage, arteriovenous malformations of the basal ganglia and thalamus should be considered for microsurgical extirpation with preoperative embolization. In experienced hands, this approach presents an expeditious and definitive opportunity to eliminate the risk of subsequent hemorrhage and resultant morbidity and mortality.

✓The authors report a unique case of subarachnoid hemorrhage caused by a traumatic pseudoaneurysm of the ophthalmic artery, which was successfully treated with coil embolization. Clinical and imaging features, as well as the relevant literature, are described.

✓ The treatment of large and giant paraclinoid carotid artery (CA) aneurysms often requires the use of suction decompression for safe and effective occlusion. Both open and endovascular suction decompression techniques have been described previously. In this article the authors describe a revised endovascular suction decompression technique that provides several advantages in the treatment of large and giant paraclinoid and CA aneurysms. A 51-year-old woman presented with a relatively brief history of progressive visual loss in the right eye, nonspecific headache, and an afferent pupillary defect. After angiography studies had been obtained, it was determined that she had a giant right paraclinoid internal CA aneurysm with a dome size of approximately 26 mm on the right and a neck diameter of 10 mm. A modified technique was performed in which suction decompression was used. With the aid of a No. 7 French Concentric balloon guide catheter (Concentric Medical, Inc., Mountain View, CA) and application of a temporary clip distal to the aneurysm, the aneurysm was trapped and decompressed using retrograde suction through the guide catheter when the balloon was inflated. After satisfactory placement of three permanent clips, an intraoperative angiogram obtained through the same guide catheter confirmed CA patency. The aneurysm was then punctured and aspirated, ensuring complete occlusion of the aneurysm sac and reconstruction of the parent vessel. The patient made an excellent recovery and did not suffer any complications. She did not experience worsening in her vision. This technical modification to endovascular suction decompression allows several potential advantages, including higher volume decompression and the ability to deliver endovascular devices to distal arterial locations.

OBJECTIVE AND IMPORTANCE: Dolichoectatic vertebrobasilar artery aneurysms are often extremely difficult, if not impossible, to treat with microneurosurgical clip reconstruction. As such, a Hunterian strategy via vertebral or basilar artery sacrifice is often used. We have encountered a patient in whom deliberate bilateral vertebral artery sacrifice was insufficient to avoid progressive expansion of a giant dolichoectatic vertebrobasilar artery aneurysm. On the basis of a review of the literature, we are unaware of another reported case. CLINICAL PRESENTATION: A 60-year-old man presented with signs and symptoms of brainstem compression from a large fusiform aneurysm involving the distal dominant vertebral and proximal basilar arteries. Results of angiographic evaluation were highly characteristic of underlying dolichoectasia. INTERVENTION: The patient was treated initially with staged bilateral vertebral artery occlusion and adjunctive posterior circulation revascularization. After this therapy failed, he underwent a trapping procedure and aneurysm deflation. CONCLUSION: Unclippable aneurysms of the vertebrobasilar system are formidable lesions. They are not uniformly treatable by direct surgical reconstruction, and their growth is not consistently stabilized by the implementation of a complete Hunterian strategy. Future developments related to the use of endovascular stent technology may offer a more successful treatment approach for patients with these complex cerebrovascular lesions.

Temporary and Permanent Occlusion of Cervical and Cerebral Arteries Richard J. Parkinson, MD*, Bernard R. Bendok, MD, Brian A. O’Shaughnessy, MD, Ali Shaibani, MD, Eric J. Russell, MD, Christopher C. Getch, MD, Issam A. Awad, MD, H. Hunt Batjer, MD Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, 233 East Erie Street, Suite 614, Chicago, IL 60611, USA Department of Radiology, Feinberg School of Medicine, Northwestern University, 676 North Clair Street, Suite 800, Chicago, IL 60611, USA

Stroke remains the leading cause of disability in adults and the third leading cause of death in the US. Carotid artery (CA) occlusive disease is the primary pathophysiological source of 10 to 20% of all strokes. Carotid endarterectomy (CEA) has been shown to reduce the risk of stroke in patients with both symptomatic and asymptomatic extracranial CA stenosis. Carotid artery angioplasty and stent placement has recently emerged as an alternative to CEA for primary and secondary prevention of stroke related to CA stenosis. With the advent of the embolic protection device, the safety of CA angioplasty and stent placement has approached, if not surpassed, that of CEA. In particular, the former has come to be considered as a first-line therapy in the management of CA stenotic disease in individuals at high risk for complications related to surgical intervention. Preliminary data from multiple registries have demonstrated that CA angioplasty and stent placement is an effective means of treating CA stenosis. The results of the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy trial have demonstrated that this modality has a significant role in the management of CA disease in symptomatic and asymptomatic patients with risk factors for high rates of surgery-related morbidity or mortality. With the completion of the Carotid Revascularization Endarterectomy versus Stent Trial, the role of CA angioplasty and stent placement in the prevention of stroke in all individuals with significant CA stenosis should be better demarcated. This treatment modality promises to assume a central role in stroke prophylaxis in patients with CA disease who are at high risk for complications related to surgery.

Intracranial aneurysms arising from the posterior wall of the supraclinoid carotid artery are extremely common lesions. The aneurysm dilation typically occurs in immediate proximity to the origin of the posterior communicating artery and, less commonly, the anterior choroidal artery (AChA). Because of the increasingly widespread use of non-invasive neuroimaging methods to evaluate patients believed to harbor cerebral lesions, many of these carotid artery aneurysms are now documented in their unruptured state, prior to occurrence of subarachnoid hemorrhage. Based on these factors, the management of unruptured posterior carotid artery (PCA) wall aneurysms is an important element of any neurosurgical practice. Despite impressive recent advances in endovascular therapy, the placement of microsurgical clips to exclude aneurysms with preservation of all afferent and efferent vasculature remains the most efficacious and durable therapy. To date, an optimal outcome is only achieved when the neurosurgeon is able to combine systematic preoperative neurovascular assessment with meticulous operative technique. In this report, the authors review their surgical approach to PCA wall aneurysms, which is greatly based on the extensive neurovascular experience of the senior author. Focus is placed on their methods of preoperative evaluation and operative technique, with emphasis on neurovascular anatomy and the significance of oculomotor nerve compression. They conclude by discussing surgery-related complications, with a particular focus on intraoperative rupture of aneurysms and their management, and the postoperative ischemic AChA syndrome.

Background The authors present a patient who experienced late (5-year follow-up) morphological progression of a dissecting aneurysm of the distal basilar artery after treatment with a combined microsurgical and neuroendovascular Hunterian strategy. In addition to postulating about the possible reasons underlying the evolution of this lesion, the role of stenting is discussed. Case Description The patient was 37 years old when she suffered a subarachnoid hemorrhage from spontaneous basilar artery dissection. At the time of the hemorrhage, minimal aneurysmal enlargement was noted angiographically, and she was therefore treated nonoperatively. On reimaging 5 months later, massive enlargement of the aneurysm was noted. The patient was treated with staged bilateral vertebral artery sacrifice using a combination of microsurgical and neuroendovascular techniques. The dominant vertebral artery was clip-ligated distal to the posteroinferior cerebellar artery, whereas the contralateral vertebral artery was coil-occluded cervically 1 week later. Conclusions Despite the patient remaining asymptomatic, follow-up angiography 5 years after the initial hemorrhage revealed further enlargement of the aneurysm as well as a newly discovered inferiorly projecting daughter sac measuring 5 mm in diameter. Clearly, certain aneurysms exist for which indirect approaches involving hemodynamic attenuation fail to prevent progression. With greater refinements in stent technology, such lesions may be more effectively treated.

The surgical management of aneurysms of the basilar apex is one of the most challenging areas in neurosurgery. Successful treatment of this subgroup of aneurysms is dependent on the mastery of technical nuances that have been pioneered and advanced over the past 4 decades. Although both the traditional transsylvian and subtemporal approaches have distinct advantages, each is associated with significant limitations. In this article, the senior author shares his insights into a hybrid approach: the extended lateral transsylvian approach. This approach combines the assets of the two traditional approaches while eliminating their liabilities.

OBJECTIVE AND IMPORTANCE Prevention of rebleeding is the most important aspect of the management of hemorrhagic moyamoya disease, because rebleeding causes significant morbidity and mortality. CLINICAL PRESENTATION A 26-year-old male patient with a history of moyamoya disease since the age of 3 years and multiple strokes was in a semicomatose state at presentation. He was found to have intraventricular and periventricular hemorrhages abutting the atrium of the right ventricle. His hospital course was complicated by a second hemorrhage. Both bleeding events were believed to be secondary to a ruptured right lateral posterior choroidal aneurysm. INTERVENTION The aneurysm was excised and revealed histopathology consistent with a true saccular aneurysm. Frameless stereotactic guidance was used during surgery to minimize damage to collateral vessels and to shorten the surgical corridor. CONCLUSION The management of hemorrhagic moyamoya disease should be modified based on the source of hemorrhage and its relation to a specifically located aneurysm. In the case of aneurysms arising from the choroidal artery, the general belief is that most of these represent pseudoaneurysms and have a tendency to regress spontaneously. Because of the rebleeding risk, we recommend early intervention in treating ruptured intracranial aneurysms using the least invasive surgical techniques.

Angiographically confirmed surgical resection is believed to be the ‘gold standard’ for cure in the treatment of intracranial arteriovenous malformations (AVMs). However, rare exceptions of recurrent AVMs have been documented. We are aware of 11 reported cases of recurrent AVMs in which complete resection of the initial lesion was confirmed by postoperative angiography. Eight of these cases were in the pediatric population. In this report, we present 2 additional cases of such recurrent lesions, review the clinical and scientific literature on this rare phenomenon and provide suggested management guidelines.

Objective and importance Dissecting aneurysms of the basilar artery are rare lesions with significant morbidity and mortality. Their management is controversial and often difficult. Although the rebleeding rate is high, clip reconstruction carries prohibitive risk because of the damage to the parent vessel induced by the dissection and the lack of tissue to gather. An enlarging pseudoaneurysm in the chronic phase, however, may have sufficient tissue for clip reconstruction. We present a case in which this strategy was used successfully. Clinical presentation A 45-year-old woman presented 3 months after an initial presentation with a subarachnoid hemorrhage from a dissecting aneurysm of the basilar trunk at an outside institution. The aneurysm had grown compared with previous angiograms. Intervention The dominant vertebral artery was sacrificed. Despite this, the aneurysm continued to enlarge. Given the progressive enlargement of the aneurysm, the decision was made to proceed with arterial reconstruction by direct surgical clipping of the saccular component of the dissecting aneurysm. The patient made an excellent recovery with a durable result. Conclusion Although clipping an intracranial pseudoaneurysm in the acute phase may carry a prohibitive risk, clipping such an aneurysm in the chronic phase may occasionally be warranted. To our knowledge, this is the first case reported in the literature in which direct surgical clipping was used as the primary mode of treatment for a basilar artery dissecting aneurysm that enlarged despite occlusion of the dominant vertebral artery. We review the literature on this rare pathological entity and discuss our management strategy.