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OBJECTIVE The surgical management of large and complex tumors of the posterior fossa poses a formidable challenge in neurosurgery. The standard retrosigmoid craniotomy approach has been performed at most neurosurgical centers; however, the retrosigmoid approach may not provide enough working space without significant retraction of the cerebellum. The transsigmoid approach provides wider and shallower surgical fields; however, there have been few clinical and no cadaveric studies on its usefulness. In the present study, the authors describe the transsigmoid approach in clinical cases and cadaveric specimens. METHODS For the clinical study, the authors retrospectively reviewed the medical records and operative charts of patients who had been surgically treated for parabrainstem tumors using the transsigmoid approach between 1997 and 2019. They analyzed patient demographic and clinical data, as well as surgical and clinical outcomes. In the cadaveric study, they compared the surgical views obtained in different approaches (retrosigmoid, presigmoid, retrolabyrinthine, and transsigmoid) and measured the sigmoid sinus width at the level of the endolymphatic sac and the distance between the anterior edge of the sigmoid sinus and the endolymphatic sac on 35 sides in 19 cadaveric specimens. RESULTS A total of 21 patients (6 males and 15 females) with a mean age of 42.2 (range 15–67) years were included in the clinical study. Eleven patients had meningioma, 7 had vestibular schwannoma, 2 had hemangioblastoma, and 1 had epidermoid cyst. Gross-total, near-total, and subtotal removal were achieved in 7 (33.3%), 3 (14.3%), and 11 (52.4%) patients, respectively. In the cadaveric study, 19 cadaveric specimens were used. The sigmoid sinus was cut in the middle, and the incision was extended from the retrosigmoid to the presigmoid dura. The dura was then retracted upward and downward like opening a door. The results indicated that this technique can widen the operative field anteriorly by approximately 2 cm as compared to the retrosigmoid approach and provides a better view anterior to the brainstem. CONCLUSIONS The transsigmoid approach is useful for complex parabrainstem tumors in the posterior fossa because it provides a wider and shallower operative view with less retraction of the cerebellum. This enables safer tumor removal with less damage to important structures in the posterior fossa, resulting in better operative and clinical outcomes.

Petrous bone lesions (PBLs) are rare with few reports in the neurosurgical literature. In this study, the authors describe our current technique of extradural subtemporal approach (ESTA). The objective of this study was to evaluate the role and efficacy of ESTA for treatment of the PBLs. To our knowledge, this is the largest reported clinical series of using an ESTA-treated PBLs in which the clinical outcomes were evaluated. Between 1994 and 2019, 67 patients with PBLs treated by ESTA were retrospectively reviewed. Extent of resection, neurological outcomes, recurrence rate, and surgical complications were evaluated and compared with previous studies. The indications, advantages, limitations, and outcomes of ESTA were analyzed according to pathology. This series included 7 facial nerve schwannomas (10.4%), 16 cholesterol granulomas (23.9%), 16 chordomas (23.9%), 6 chondrosarcomas (9%), 5 trigeminal schwannomas (7.5%), 9 epidermoids/dermoids (13.4%), and 8 other pathologies (11.9%). The most common location of PBLs operated with ESTA was at the petrous apex and rhomboid areas (68.7%). Gross total resection was achieved in 35 (55.6%). Symptomatic improvement occurred in 56 patients (83.6%). Complications occurred in 7 (10.4%) of cases including one mortality. Nine patients (17%) had recurrence within the mean follow-up 71 months. Compared to previous literature, our results demonstrated comparable outcomes but with higher rates of hearing and facial nerve preservation as well as minimal morbidity. From our results, ESTA is an effective therapeutic option for lesions located at the rhomboid and petrous apex, particularly when patients presented with intact facial and hearing function. Our series demonstrated that ESTA provided satisfactory outcomes with excellent benefits of hearing and facial function preservation for patients with petrous bone lesions. ESTA should be considered as a safe and effective therapeutic option for selected patients with PBLs.

Surgery of petrous bone lesions (PBLs) is challenging for neurosurgeons. Selection of the surgical approach is an important key for success. In this study, the authors present an anatomical classification for PBLs that has been used by our group for over the past 26 years. The objective of this study is to investigate the benefits and applicability of this classification. Between 1994 and 2019, 117 patients treated for PBLs were retrospectively reviewed. Using the V3 and arcuate eminence as reference points, the petrous bone is segmented into 3 parts: petrous apex, rhomboid, and posterior. The pathological diagnoses, selection of the operative approach, and the extent of resection (EOR) were analyzed and correlated using this classification. This series included 22 facial nerve schwannomas (18.8%), 22 cholesterol granulomas (18.8%), 39 chordomas/chondrosarcomas (33.3%), 6 trigeminal schwannomas (5.1%), 13 epidermoids/dermoids (11.1%), and 15 other pathologies (12.8%). PBLs were most often involved with the petrous apex and rhomboid areas (46.2%). The extradural subtemporal approach (ESTA) was most frequently used (57.3%). Gross total resection was achieved in 58.4%. Symptomatic improvement occurred in 92 patients (78.6%). Our results demonstrated a correlation between this classification with each type of pathology (p

Resection of giant sphenoclinoidal meningiomas (SCLM) remains difficult. We discuss a patient presenting with right eye near blindness who underwent total removal of a giant SCLM, resulting in normal vision and no recurrence. Utilizing frontotemporal craniotomy, devascularization, debulking, and detachment was achieved. Microdissection of tumor off the optic nerve and carotid perforators was accomplished, resulting in total resection, visual normalization, and no deficits using efficient face-to-face microscope set-up, 2-surgeon 4-hand technique, and double bipolar-suction arrangement. Frontotemporal craniotomy was adequate. Preservation of the optic nerve and carotid artery is key. Meticulous microsurgical techniques and refined instruments are important for success.

To demonstrate the utility and limitations of the extradural endoscopic–assisted anterior temporal fossa approach to the pterygopalatine fossa (PPF), infratemporal fossa (ITF), paranasal sinuses (PS), parapharyngeal region (PPR), nasal cavities (NC), epipharynx (EP), and clivus. A frontotemporal orbitozygomatic craniotomy is performed. The dura is elevated from the cavernous sinus (CS). The anterior temporal fossa floor is drilled. Foramen rotundum and ovale are opened. The PPF is exposed and the lateral margin of inferior orbital fissure (IOF) is removed. The anterolateral triangle (ALT) is drilled and the vidian nerve (VN) is exposed. Drilling between the maxillary nerve (V2) and the VN provides access to the sphenoid sinus (SphS). The medial pterygoid plate is drilled exposing the EP. The maxillary sinus (MaxS) is opened anterior to the PPF. V2 is transposed laterally to enlarge the anteriomedial triangle (AMT). The orbital muscle of Muller is removed as well as the medial margin of the IOF, which opens the SphS. Anteriorly, the posterior ethmoid air cells are opened. Morphometric measurements evaluating the size of the ALT were done and the PS, NC, EP were explored with the endoscope. The ALT and AMT triangle provides a wide exposure of the PPF, ITF, PPR. In addition, those triangles represent a deep entry point to explore the PS, NC, and EP. The ALT and AMT are useful corridors to access to the SphS, MaxS, PS, NC, and EP via a transcranial approach. The use of the endoscope through this corridor widely extend the extradural anterior temporal fossa approach which may be considered as a valuable alternative to the extended endoscopic endonasal approach for selected skull base lesions extending both intracranial and into the PS, NC and EP.

Koos grade IV vestibular schwannomas (VS) (maximum diameter3 cm) compress the brainstem and displace the fourth ventricle. Microsurgical resection with attention to the right balance between preservation of function and maximal tumor removal is the treatment of choice. Our series consists of 60 consecutive patients with unilateral VS, operated on from December 2010 to July 2019. All patients underwent microsurgical removal via the retrosigmoid approach. The adherence of VS' capsule to the surrounding nervous structures and the excessive tendency of tumor to bleed during debulking, because of a redundant vascular architecture, was evaluated by reviewing video records. Microsurgical removal of tumor was classified as total (T), near-total (NT: residue5%), subtotal (ST: residue 5-10%), or partial (P: residue10%). Maximal mean tumor diameter was 3,97 cm (SD ± 1,13; range 3,1-5,8 cm). Preoperative severely impaired hearing or deafness (AAO-HNS classes C-D) was present in 52 cases (86,7%). Total or NT resection was accomplished in 46 cases (76,7%), 65,8% in cases with, and 95,4% without tight adhesion of capsule to nervous structures (p0,001). Endoscopic-assisted microsurgical removal of VS in the IAC was performed in 23 patients: in these cases, a T resection was obtained in 78,3% versus 45,9% of microsurgery only (p0,001). The capsule of VS was tightly adherent to nervous structures in 63,3% of patients, whereas hypervascular high-bleeding tumors represented 56,7%. Hearing preservation was possible in 2 out of 8 patients with preoperative class B hearing. At last follow-up, 34 (56,7%) patients had a normal postoperative FN outcome (HBI), 9 (15,0%) were HBII, 8 (13,3%) HBIII, and 9 (15,0%) HBIV. The total NT resection of solid and low-bleeding VS, without tight capsule adhesion, was associated with better FN outcome. Mortality was zero; permanent complications were observed in 2 cases (diplopia, hydrocephalus), transient in 9. Microsurgery of Koos grade IV VS seems to be associated with more than acceptable functional results, with high rate of T and NT removal of tumor. Long-term FN results seem to be worse in patients with cystic Koos grade IV VS, in cases with tight capsule adherences to nervous structures and in high-bleeding tumors.

BackgroundCatheter retention and difficulty in retrieval have been observed during embolization of brain arteriovenous malformations (bAVMs) with the Onyx liquid embolic system (Onyx). The Apollo Onyx delivery microcatheter (Apollo) is a single lumen catheter designed for controlled delivery of Onyx into the neurovasculature, with a detachable distal tip to aid catheter retrieval. This study evaluates the safety of the Apollo for delivery of Onyx during embolization of bAVMs.MethodsThis was a prospective, non-randomized, single-arm, multicenter, post-market study of patients with a bAVM who underwent Onyx embolization with the Apollo between May 2015 and February 2018. The primary endpoint was any catheter-related adverse event (AE) at 30 days, such as unintentional tip detachment or malfunction with clinical sequelae, or retained catheter. Procedure-related AEs (untoward medical occurrence, disease, injury, or clinical signs) and serious AEs (life threatening illness or injury, permanent physiological impairment, hospitalization, or requiring intervention) were also recorded.ResultsA total of 112 patients were enrolled (mean age 44.1±17.6 years, 56.3% men), and 201 Apollo devices were used in 142 embolization procedures. The mean Spetzler–Martin grade was 2.38. The primary endpoint was not observed (0/112, 0%). The catheter tip detached during 83 (58.5%) procedures, of which 2 (2.4%) were unintentional and did not result in clinical sequelae. At 30 days, procedure related AEs occurred in 26 (23.2%) patients, and procedure-related serious AEs in 12 (10.7%). At 12 months, there were 3 (2.7%) mortalities, including 2 (1.8%) neurological deaths, none of which were device-related.ConclusionThis study demonstrates the safety of Apollo for Onyx embolization of bAVMs.Clinical trial registrationCNCT02378883.

Unruptured intracranial saccular aneurysms occur in 3-5% of the general population. As the use of diagnostic medical imaging has steadily increased over the past few decades with the increased availability of computed tomography (CT) and magnetic resonance imaging (MRI), so has the detection of incidental aneurysms. The management of an unruptured intracranial saccular aneurysm is challenging for both patients and physicians, as the decision to intervene must weigh the risk of rupture and resultant subarachnoid hemorrhage against the risk inherent to the surgical or endovascular procedure. The purpose of this paper is to provide an overview of factors to be considered in the decision to offer treatment for unruptured intracranial aneurysms in adults. In addition, we review aneurysm and patient characteristics that favor surgical clipping over endovascular intervention and vice versa. Finally, the authors propose a novel, simple, and clinically relevant algorithm for observation versus intervention in unruptured intracranial aneurysms based on the PHASES scoring system.

Fusiform aneurysms are less common than saccular aneurysms, but have higher associated mortality and rebleeding rates. Recently, flow diversion has emerged as a possible treatment option. The purpose of this study was to determine the safety and efficacy of the Pipeline Embolization Device (PED) for the treatment of ruptured and unruptured fusiform aneurysms. This was a retrospective analysis of patients with fusiform intracranial aneurysms treated with a PED at a quaternary care center between January 2012 and September 2019. Occlusion rates, neurologic morbidity/mortality, and other clinical variables were analyzed. Twenty-nine patients with 30 fusiform aneurysms were treated with a PED. Sixteen aneurysms (53%) were located in the anterior circulation and 14 aneurysms (47%) were in the posterior circulation. The mean maximal diameter of the aneurysms was 10.1 ± 5.6 mm (range 2.3–25 mm). Angiographic and clinical follow-up were available for 28 aneurysms (93%). The median follow-up was 17.4 months (IQR 4.8 to 28 months) and occlusion rates were graded according to the O’Kelly-Marotta (OKM) scale. Of patients with DSA follow-up, 15 aneurysms (60%) were completely occluded (OKM D) and 19 aneurysms (76%) had a favorable occlusion result (OKM C1-3 and D). The overall complication rate was 26.7% with a neurological morbidity rate of 6.7% and neurological mortality rate of 3.4%. Flow diversion can be an effective treatment for both ruptured and unruptured fusiform aneurysms. Nevertheless, complete occlusion rates are lower than for saccular aneurysms. Therefore, flow diversion should be considered only if other more direct treatment options, such as clipping or stent/coiling are not applicable. Flow diversion should be used cautiously in patients presenting with rupture.

Background Flow-diverting stents have revolutionized the endovascular treatment of intracranial aneurysms. The purpose of this study is to identify predictors of adverse outcomes associated with the pipeline embolization device (PED). Methods A retrospective analysis of all patients treated with PED at a single high-volume center from January 2014 to September 2018. Patient outcomes, neurologic morbidity/mortality, and other clinical variables were analyzed. Results We treated 204 aneurysms in 170 patients with PED. Mean length of follow-up was 11 months. Most (181) aneurysms (89%) were located in the anterior circulation, and 23 (11%) were found in the posterior circulation. Most aneurysms were saccular (82%), followed by fusiform (11%), blister (4%), and dissecting pseudoaneurysms (3%). Mean aneurysm size was 8.2 + 5.7 mm with 145 (71%) small aneurysms (≤10 mm), 53 (26%) large aneurysms (between 10 and 25 mm), and 6 (3%) giant aneurysms (≥25 mm). Ninety-two percent of aneurysms were unruptured, and 8% were ruptured. The overall major neurologic morbidity/mortality was 4.7% and 1.8%, respectively. The all-cause mortality was 2.9%. Predictors of neurologic morbidity/mortality included the baseline modified Rankin Scale (P = 0.001), aneurysm neck size (P = 0.003), aneurysm size (P = 0.006), anterior versus posterior location (P = 0.02), and rupture at presentation (0.006). The P2Y12 Reactivity Unit, parent vessel diameter, and patient age did not correlate with adverse events. Conclusions The PED has a satisfactory safety profile in both on- and off-label indications. A poor clinical patient baseline, wider aneurysm neck or larger size, and rupture predict an increased risk of an unfavorable outcome.

Background Lesions located at the petrous apex, cavernous sinus, clivus, medial aspect of the jugular foramen, or condylar regions are still difficult to fully expose using the operating microscope. Although approaches to this region through the middle cranial fossa have been previously described, these approaches afford only limited visualization. We have confirmed a transcranial infratemporal fossa combined microsurgical and endoscopic access to the petrous apex, clivus, medial aspect of the jugular foramen, and occipital condyle. We have presented the results of a micro-anatomical cadaver dissection study and its clinical application. Methods Ten latex-injected cadaveric specimens (20 twenty sides) underwent dissection with navigational guidance to achieve an extended anterior petrosal approach combined with a far vidian corridor approach (between the foramen rotundum and foramen ovale). We performed anatomical dissections to confirm the surgical anatomy and the feasibility and limitations of this approach. Anatomical dissections were performed in the skull base laboratory of Lariboisiere Hospital and Duke University Medical Center. This approach was then applied to some clinical cases. Results The combination of the microscope and endoscope, aided by surgical navigation, was extremely effective and provided a wide view of the petrous rhomboid, the entire clivus, and the medial condylar regions. The extended extradural anterior petrosal approach provided a large corridor to petrous and clival lesions. Endoscopic assistance allows for wide and deep exposure of the middle to lower clivus, epipharyngeal space, and bilateral condylar regions. This approach successfully provided adequate surgical access for resection of tumors located in these regions. The depth of the medial aspect of the jugular foramen was 16.3 ± 1.2 mm deep from the geniculate ganglion. The emerging point of the inferior petrosal sinus in the jugular foramen was 16.5 ± 1.8 mm deep from the geniculate ganglion. The hypoglossal canal was 21.6 ± 2.2 mm deep from the geniculate ganglion. The foramen magnum was located 31.5 ± 2.4 mm deep from the gasserian ganglion. The inferior petrosal sinus was found to be a reliable landmark to identify the medial portion of the jugular bulb. The introduction of the endoscope through the middle fossa rhomboid enabled visualization of the medial aspect of the jugular bulb, which otherwise would be hampered by the internal auditory canal under the microscope. Conclusion After microscopic exposure of the middle fossa rhomboid, neuronavigational endoscopic assistance facilitated visualization of the ventral cavernous region, petrous apex, retropharyngeal space, and middle and inferior clivus down to the medial aspect of the jugular bulb and condyle regions. Additional maxillary nerve–mandibular nerve vidian corridor visualization provides a lateral transsphenoidal approach to upper clivus lesions.

Background Minimally invasive surgery procedures, including stereotactic catheter aspiration and clearance of intracerebral hemorrhage (ICH) with recombinant tissue plasminogen activator hold a promise to improve outcome of supratentorial brain hemorrhage, a morbid and disabling type of stroke. A recently completed Phase III randomized trial showed improved mortality but was neutral on the primary outcome (modified Rankin scale score 0 to 3 at 1 yr). Objective To assess surgical performance and its impact on the extent of ICH evacuation and functional outcomes. Methods Univariate and multivariate models were used to assess the extent of hematoma evacuation efficacy in relation to mRS 0 to 3 outcome and postulated factors related to patient, disease, and protocol adherence in the surgical arm (n = 242) of the MISTIE trial. Results Greater ICH reduction has a higher likelihood of achieving mRS of 0 to 3 with a minimum evacuation threshold of ≤15 mL end of treatment ICH volume or ≥70% volume reduction when controlling for disease severity factors. Mortality benefit was achieved at ≤30 mL end of treatment ICH volume, or >53% volume reduction. Initial hematoma volume, history of hypertension, irregular-shaped hematoma, number of alteplase doses given, surgical protocol deviations, and catheter manipulation problems were significant factors in failing to achieve ≤15 mL goal evacuation. Greater surgeon/site experiences were associated with avoiding poor hematoma evacuation. Conclusion This is the first surgical trial reporting thresholds for reduction of ICH volume correlating with improved mortality and functional outcomes. To realize the benefit of surgery, protocol objectives, surgeon education, technical enhancements, and case selection should be focused on this goal.

A new technique for collaborative performance of complex skull base and cerebrovascular procedures is described. The benefits of this approach for patient safety and surgical education are discussed.

CSF fistulas into the soft tissues of the skull base can cause wound breakdown and/or pseudomeningocele, which often becomes very painful and debilitating. In addition, drainage of spinal fluid from the skin increases the risk for surgical site infections and meningitis. Diverse techniques for posterior cranial fossa dural reconstruction and closure have been reported: application of synthetic dural patches, incorporation of autologous tissues, and augmentation with “muscle plugs.” Even if a variety of dural substitutes is currently available, many articles in the literature suggest that autologous materials are preferable compared to nonautologous substitutes. Our group reported the use of autologous pericranium harvested during the opening step of retrosigmoid approach, inserted and stitched as an underlay hourglass-shaped plug for dural closure. We did not observe any surgical site infections, meningitis, CSF leaks, or new neurological symptoms using properly this dural closure technique.

Background Giant vertebral and vertebrobasilar aneurysms have proven to be extremely challenging vascular entities to treat despite many advances in microsurgical and endovascular techniques. In recent years, there has been more attention paid to combined approaches, including combinations of endovascular and surgical procedures in hopes of decreasing the associated morbidity and mortality of these lesions. Clinical Presentation We present a case of a giant fusiform vertebral artery aneurysm that was initially treated with flow-diverting stents. After the failure of flow diversion to occlude the aneurysm, the lesion was definitively treated with an occipital artery to the posterior inferior cerebellar artery (PICA) bypass and coil embolization of residual aneurysm. Conclusion After bypass and parent vessel deconstruction, angiography confirmed the aneurysm has remained occluded and the PICA patent. This case highlights the use of an extracranial-to-intracranial bypass to salvage a complex residual aneurysm after failed flow diversion.

The need for revascularization with proximal posterior cerebral artery occlusion in the treatment of giant and fusiform aneurysms is unclear. While early series demonstrated only about a 10% chance of infarction following posterior cerebral artery occlusion, recently several authors have advocated a bypass prior to parent vessel sacrifice in all cases. We present the case of an adult man with a fusiform aneurysm of the right posterior cerebral artery at the P2-P3 junction. He clinically failed a balloon test occlusion preoperatively and therefore underwent an occipital artery to distal posterior cerebral artery bypass with subsequent endovascular occlusion of the parent vessel and aneurysm. Despite the fact that the immediate and 6 month follow up cerebral angiography confirmed a patent bypass, the patient still developed a posterior cerebral artery territory stroke. We believe this case demonstrates that successful distal revascularization in the setting of proximal posterior cerebral artery occlusion does not guarantee against cerebral ischemia and infarction even in those patients that fail a test occlusion.

Objective This study describes the safety and efficacy of mometasone furoate eluting stents in the management of petrous apex cholesterol granuloma approached through an endonasal endoscopic route and assesses the restenosis rate. Methods Consecutive patients undergoing endoscopic endonasal marsupialization of a petrous apex cholesterol granuloma at a tertiary referral center who had a mometasone furoate eluting stent placed intraoperatively were reviewed in a retrospective fashion. Postoperative endoscopy was used to determine success of surgery and stenting. Results Five patients were included in the study, three were primary cases and two patients had revision surgeries performed. The steroid eluting stent was placed successfully and safely in all patients with no dural or vascular injuries. The average follow-up duration was 10.6 months. There was no restenosis in three patients and one patient had an immediate restenosis that was debrided in clinic (revision case). This was patent at the 16 months follow-up. One patient also developed stenosis, 4 months after surgery due to sphenoid sinusitis. Conclusion Mometasone furoate eluting stents are safe and effective in the primary management of petrous apex cholesterol granuloma. Further studies are needed to assess their efficacy in revision cases and for long term results.

Dermoid cysts are rare in the skull base. There have been 10 reported cases of dermoid cysts in the cavernous sinus, two in the petrous apex, and one in the extradural Meckel cave. This is the first case report of a dermoid cyst in the anterior infratemporal fossa attached to the anterior dura of the foramen ovale. The clinical presentation, radiologic findings, histologic features, tumor origin, and operative technique are described along with a review of the literature.

Aneurysmal subarachnoid hemorrhage (SAH) remains an important health issue in the United States. Despite recent improvements in the diagnosis and treatment of cerebral aneurysms, the mortality rate following aneurysm rupture. In those patients who survive, up to 50% are left severely disabled. The goal of preventing the hemorrhage or re-hemorrhage can only be achieved by successfully excluding the aneurysm from the circulation. This article is a comprehensive review by contemporary vascular neurosurgeons and interventional neuroradiolgists on the modern management of cerebral aneurysms.

Background and importance Iatrogenic internal carotid artery (ICA) injuries during endoscopic endonasal approach (EEA) surgeries are associated with a high morbidity and mortality, with few acceptable methods described for repair. Clinical presentation A 13-year-old girl with a large anterior and central skull base osteoblastoma incurred an iatrogenic cavernous ICA injury during a staged EEA approach. Intraoperative angiogram was performed with balloon-assisted EEA primary microsurgical repair of the lacerated ICA. Conclusion By integrating current techniques commonly used in open aneurysm surgeries and in endovascular procedures, we developed a rapid, safe technique to repair an EEA-associated iatrogenic ICA injury.

Surgery of the infratemporal fossa (ITF) and parapharyngeal area presents a formidable challenge to the surgeon due to its anatomical complexity and limited access. Conventional surgical approaches to these regions were often too invasive and necessitate sacrifice of normal function and anatomy. To describe a less invasive transcranial extradural approach to ITF parapharyngeal lesions and to determine its advantages, 17 patients with ITF parapharyngeal neoplasms who underwent tumor resection via this approach were enrolled in the study. All lesions located in the ITF precarotid parapharyngeal space were resected through a small operative corridor between the trigeminal nerve third branch (V3) and the temporomandibular joint (TMJ). Surgical outcomes and postoperative complications were evaluated. Pathological diagnosis included schwannoma in eight cases, paraganglioma in two cases, gangliocytoma in two cases, carcinosarcoma in one case, giant cell tumor in one case, pleomorphic adenoma in one case, chondroblastoma in one case, and juvenile angiofibroma in one case. Gross total resection was achieved in 12 cases, near-total and subtotal resection were in 3 and 2 cases, respectively. The most common postoperative complication was dysphagia. Surgical exposure can be customized from minimal (drilling of retrotrigeminal area) to maximal (full skeletonization of V3, removal of all structures lying lateral to the petrous segment of internal carotid artery) according to tumor size and location. Since the space between the V3 and TMJ is the main corridor of this approach, the key maneuver is the anterior translocation of V3 to obtain an acceptable surgical field.

Background Loeys-Dietz syndrome (LDS) results from mutations in receptors for the cytokine transforming growth factor-β leading to aggressive aortic pathology sometimes accompanied by specific phenotypic features including bifid uvula, hypertelorism, cleft palate, and generalized arterial tortuosity. We reviewed our adult surgical experience with LDS in order to validate current recommendations regarding management of this newly described disease. Methods All adult (≥ 18 years old) patients with LDS undergoing surgical treatment at a single referral institution from September 1999 to May 2013 were retrospectively reviewed. Results Eleven adult LDS patients were identified by clinical criteria and genotyping. Seven (64%) experienced acute type A dissection at some point in their lives. All eventually required aortic root replacement, and 73% required multiple vascular surgical interventions. Over a mean follow-up of 65 ± 49 months, 2.8 cardiovascular procedures per patient were performed. In patients with type A dissection, a mean of 3.4 operations were performed versus 1.8 operations for patients without dissection. Total aortic replacement was required in 5 patients (45%) and 2 (18%) required neurosurgical intervention for cerebrovascular pathology. There was 1 late death from infectious complications, and no deaths from vascular catastrophe. Conclusions These results confirm the aggressive nature of LDS aortic pathology. However, the improved survival compared with earlier LDS reports suggest that aggressive treatment strategies may alter outcomes and improve the natural history of this syndrome.

Objective Therapeutic embolization of the common carotid artery (CCA), internal carotid artery (ICA), and vertebral artery (VA) is necessary in the treatment of a subset of chronic arteriovenous fistulas (AVFs), hemorrhages, highly vascularized neoplasms before resection, and giant aneurysms. There are currently no reports of the use of the AMPLATZER Vascular Plug II (AVP II) device to occlude the CCA, ICA, or VA. The objective of this article is to present the Duke Cerebrovascular Center experience using the AVP II device in neurointerventional applications. Methods This case series is a retrospective review of all of the cases at Duke University Hospital in which an AVP II device was used in the CCA, ICA, or VA up to September 2012. The AVP II device was often used in conjunction with embolization coils or as multiple AVP II devices deployed in tandem. Results During 2010–2012, 8 cases meeting criteria were performed. These included 2 chronic VA to internal jugular AVFs, 1 hemorrhagic CCA to internal jugular AVF secondary to invasive head and neck squamous cell carcinoma, 1 ICA hemorrhage secondary to invasive head and neck squamous cell carcinoma, 1 ICA hemorrhage secondary to trauma, 1 ruptured ICA aneurysm, 1 giant petrous ICA aneurysm, and 1 case of cervical vertebral sarcoma requiring preoperative VA embolization. Successful occlusion of the target vessel was achieved in all 8 cases. There was 1 major complication that consisted of a watershed distribution cerebral infarct; however, this was related to emergent occlusion of the ICA in the setting of intracranial hemorrhage and was not a problem intrinsic to the AVP II device. Conclusions The AVP II device is relatively large, self-expanding vascular occlusion device that safely allows enhanced, rapid take-down of the CCA, ICA, and VA with low risk of distal migration.

Background Dissecting aneurysms of the intracranial vertebral arteries are rare; however, treatment of these presents multiple challenges, including high risk of rebleeding, development of thromboembolic strokes, and progressive partial thrombosis. Flow diverters, such as Pipeline Endovascular Devices (PEDs; Covidien, Medtronic Inc, Dublin, Ireland), have emerged as a potential treatment option. Objective To present our experience with patients treated at our institution with PEDs for dissecting distal vertebral artery (V4 segment) aneurysms. Methods A retrospective search of our prospectively maintained database was performed between January 2014 and December 2016. We queried our database for all patients treated with PED for dissecting aneurysms of the V4 segment. Information was gathered including demographics, the location and morphology of the aneurysm, the clinical presentation, specific form of treatment, complications, antiplatelet medication regimen, and follow-up time. Results There were a total of 9 patients with dissecting V4 aneurysms treated with PED during the study period. All were treated initially with an average of 1.2 PEDs. All patients were followed with at least one repeat diagnostic angiogram and there was no residual aneurysm seen in 8 of 9 cases. In those that presented with neurological deficits, there was an average improvement in modified Rankin Scale of 2.85 points. Conclusion PED is a safe and effective tool that can be used to treat ruptured dissecting aneurysms of this specific segment of the posterior circulation, but it does require close management of antiplatelet therapy in the setting of subarachnoid hemorrhage and close angiographic follow-up.

Spinal dural arteriovenous fistulas (dAVF) are the most common subset of the larger group of spinal vascular malformations. In this chapter, we discuss the definition, epidemiology, clinical presentation, diagnosis, treatment, and outcomes of spinal dAVF. Special attention is given to clinical approach, imaging, and diagnosis with discussion of newer spinal magnetic resonance angiographic techniques. Endovascular management techniques are discussed, including technical and safety considerations for the performance of spinal angiography and various methods of embolization. Embolization media, including liquid embolics, particles, and coils, are introduced. Finally, clinical and imaging outcomes are discussed with attention to the clinical and imaging findings of dAVF recurrence.

Object Cerebral artery vasospasm is a major cause of death and disability in patients recovering from subarachnoid hemorrhage (SAH). Although the exact cause of vasospasm is unknown, one body of research suggests that clearing blood products by CSF drainage is associated with a lower frequency and severity of vasospasm. There are multiple approaches to facilitating CSF drainage, but there is inadequate evidence to determine the best practice. The purpose of this study was to explore whether continuous or intermittent CSF drainage was superior for reducing vasospasm. Methods The authors performed a randomized clinical trial. Within 72 hours of admission for SAH, patients with an external ventricular drain (EVD) were randomized to undergo continuous CSF drainage with intermittent intracranial pressure (ICP) monitoring (open-EVD group) or continuous ICP monitoring with intermittent CSF drainage (monitor-ICP group). Results After 60 patients completed the study, an interim analysis was performed. The complication rate of 52.9% for the open-EVD group was significantly higher than the 23.1% complication rate for the monitor-ICP group (OR 3.75, 95% CI 1.21–11.66, p = 0.022). These results were reported to the Data Safety and Monitoring Board and enrollment was terminated. The odds ratio of vasospasm for the open-EVD versus monitor-ICP group was not significant (OR 0.44, 95% CI 0.13–1.45, p = 0.177). Conclusions Continuous CSF drainage with intermittent ICP monitoring is associated with a higher rate of complications than continuous ICP monitoring with intermittent CSF drainage, but there is no difference between the two types of monitoring in vasospasm. Clinical trial registration no.: NCT01169454 (clinicaltrials.gov).

Background: Oculomotor nerve palsy (OMNP) is a well-recognized complication of posterior communicating artery (PCOM) aneurysms. Only a few comparative studies have assessed the effect of clipping versus coiling on recovery from OMNP in PCOM aneurysms. A retrospective review and meta-analysis was conducted to assess the relationship between PCOM aneurysm treatment and OMNP. Materials and Methods: Medical records of all patients presenting between January 2000 and February 2013 with intracranial aneurysm were searched. All patients with OMNP secondary to PCOM aneurysm were included for analysis. Patients undergoing surgical clipping or endovascular coiling were compared with respect to complete resolution of OMNP after aneurysm surgery (i.e., primary outcome). A meta-analysis of published studies of OMNP associated with PCOM aneurysm was performed after a MEDLINE search. Results: Seventeen patients with OMNP secondary to PCOM aneurysms met the inclusion criteria. Surgical clipping (seven of eight patients, or 87.5%) resulted in greater complete resolution of OMNP compared with endovascular coiling (four of nine patients, or 44.4%), P = 0.13. A meta-analysis of similar studies revealed that complete resolution of OMNP was more commonly associated with surgical clipping (36 of 43 patients, or 83.7%) than with endovascular coiling (29 of 55 patients, or 52.7%), yielding an adjusted odds ratio (OR) of 6.04 [confidence interval (CI) =1.88-19.45, P = 0.003]. Multivariate analysis found that the degree of pre-operative OMNP (OR = 0.07, CI = 0.02-0.28, P = 0.001) and surgical clipping (OR = 6.37, CI = 1.73-23.42, P = 0.005) were significant factors that affected the complete recovery of OMNP. Conclusion: Complete recovery of OMNP with PCOM aneurysms is more commonly associated with surgical clipping than with endovascular coiling. Also, the degree of pre-operative OMNP and the treatment modality are significant factors that affect the complete recovery of OMNP.

BACKGROUND : Treatment of unruptured intracranial aneurysms (UIAs) involves endovascular coiling or aneurysm clipping. While many studies have compared these treatment modalities with respect to various clinical outcomes, few studies have investigated the economic costs associated with each procedure. OBJECTIVE : To determine the reoperation rate, postoperative complications, and inpatient and outpatient costs associated with surgical or endovascular treatment of patients with UIAs in the United States. METHODS : We utilized the MarketScan database to examine patients who underwent surgical clipping or endovascular coiling procedures for UIAs from 2000 to 2009, comparing reoperation rates, complications, and angiogram and healthcare resource use. Propensity score matching techniques were used to match patients. RESULTS : We identified 4,504 patients with surgically treated UIAs, with propensity score matching of 3,436 patients. Reoperation rates were significantly lower in the clipping group compared to the coiling group at 1- (P < .001), 2- (P < .001), and 5 years (P < .001) following the procedure. However, postoperative complications (immediate, 30 and 90 days) were significantly higher in those undergoing surgical clipping. Although hospital length of stay and costs were higher in the clipping group for the index procedure, the number of postoperative angiograms and outpatient services used at 1, 2, and 5 years were significantly higher in the coiling group. CONCLUSION : Though surgical clipping resulted in lower reoperation rates, it was associated with higher complication rates and initial costs. However, overall costs at 2 and 5 years were similar to endovascular coiling due to the significantly higher number of follow-up angiograms and outpatient costs in these patients. ABBREVIATIONS : SAH, subarachnoid hemorrhageUIAs, unruptured intracranial aneurysms.

BACKGROUND Despite advanced microsurgical techniques, more refined instrumentation, and expert team management, there is still a significant incidence of complications in vestibular schwannoma surgery. OBJECTIVE To analyze complications from the microsurgical treatment of vestibular schwannoma by an expert surgical team and to propose strategies for minimizing such complications. METHODS Surgical outcomes and complications were evaluated in a consecutive series of 410 unilateral vestibular schwannomas treated from 2000 to 2009. Clinical status and complications were assessed postoperatively (within 7 days) and at the time of follow-up (range, 1-116 months; mean, 32.7 months). RESULTS Follow-up data were available for 357 of the 410 patients (87.1%). Microsurgical tumor resection was performed through a retrosigmoid approach in 70.7% of cases. Thirty-three patients (8%) had intrameatal tumors and 204 (49.8%) had tumors that were

Management of intracranial aneurysms continues to evolve, with coiling of aneurysms becoming an increasingly used modality. However, for aneurysms which are considered to be “complex” due to their size, position, or morphology, clipping continues to be the preferred treatment option. Several techniques can be utilized intraoperatively to facilitate aneurysm exposure and clip ligation. These include deep hypothermic circulatory arrest, endovascular balloon occlusion with suction, and, most commonly, temporary clip application to the proximal feeding vessel. The use of these techniques has been limited by the associated significant morbidity and mortality, and in the case of temporary clipping, anatomic limitations preventing clip application in certain cases. Recently, adenosine induced transient circulatory arrest has undergone a resurgence in neurosurgical practice to assist in complex aneurysm clip ligation. In this article we review this technique with special emphasis on appropriate patient selection and safety profile.

Acute ischemic stroke (AIS) in the pediatric population occurs in 2.3 of 100 000 children.1,2 With a mortality of 3% to 6% and morbidity up to 70%, patients with pediatric AIS experience recurrent strokes, life-long deficits, and decreased quality of life.3,4 The outcome of pediatric AIS is worsened by delayed diagnosis and lack of treatment protocols.5 Children are often brought in early after symptom onset (on average 1.7 hours after onset). There is a 12.7-hour median time to diagnosis, with >50% of diagnoses made >24 hours after arrival.6–9 Common differentials include epilepsy, complex migraines, inflammatory disease, intracranial infection, and intracranial tumors. In adult AIS, there is overwhelming evidence to support intravenous (IV) tissue-type plasminogen activator (tPA) within 4.5 hours of symptom onset and mechanical thrombectomy for large vessel occlusions within 6 hours of symptom onset.10–15 With the delay in diagnosis and lack of treatment protocols in the pediatric population, the efficacy and safety of these treatment strategies are unknown in this population. To date, there are no prospective trials on endovascular treatment in children. However, multiple case reports have demonstrated promising results. We performed here a retrospective case review of endovascular management of pediatric AIS, with a focus on efficacy and safety. We performed a PubMed search of all pediatric AIS cases managed with endovascular treatment from January 1990 through October 2016 using the following medical subject headings (MESH) keywords: child, pediatric, stroke, thrombolysis, endovascular, thrombectomy, tissue plasminogen activator, and case report. We also searched the relevant articles in the bibliographies. All English written articles with reports of patients

Background Tandem occlusions of the internal carotid artery (ICA) and middle cerebral artery (MCA) occur in up to a third of patients with acute ischemic strokes undergoing endovascular mechanical thrombectomy. Understanding open neurosurgical management of associated complications with this procedure is important. Case Report A 67-year-old man with acute onset of left hemiparesis and a tandem right ICA and MCA occlusion. He underwent carotid stent angioplasty of a stenotic ICA, followed by attempted Solitaire stent retrieval of an MCA clot. On withdrawal, the tines of the Solitaire stent lodged inside the Precise carotid stent. The patient was started on aspirin, Plavix, and heparin infusion, and underwent a carotid endarterectomy (CEA) with safe removal of the stents and primary vessel repair. Conclusion This is the first case reported to date of a Solitaire stent becoming lodged inside a Precise carotid stent, salvaged by CEA with safe removal of the stents and primary vessel repair. We discuss the timing, indication, alternatives, and technical nuances of a CEA in this setting.

Various strategies are emerging for dosing antiplatelet therapies in preparation for pipeline stent embolization in adults. Hyper-response is associated with hemorrhagic complications. Hypo-response is associated with thromboembolic events. Dosing of antiplatelet agents is highly variable, with little consensus among experts for adults–and even more so for children. To date, pipeline stents have been deployed in 11 pediatric patients, ages 4–15. A variety of clopidogrel and aspirin dosing regimens have been used, with response tested in only three patients, who were all therapeutic. Thrombotic events occurred in two patients, neither of whom were tested. We describe here the first case of a hemorrhagic complication in a hyper-responsive pediatric patient undergoing placement of a pipeline stent. As the use of endovascular therapies requiring dual anti-platelet agents becomes more established, there is an increasing need to develop titration protocols that minimizes the risk of thrombotic and hemorrhagic events.

Background Approximately 95% of tumors occurring within the internal auditory canal (IAC) are vestibular schwannomas. Many undergo stereotactic radiation without definitive tissue diagnosis. Rare IAC tumors are not all radiosensitive and are poorly described. Methods Between 1992 and 2015, 289 consecutive patients with IAC lesions operated on were reviewed retrospectively. Results Fifteen patients (5.2%) (16 operations) had unusual histologic findings, including nonvestibular schwannomas (2 facial schwannomas, 2 cochlear schwannomas, 2 intermedius schwannomas), 3 meningiomas, 3 cavernous hemangiomas, a mucosa-associated lymphoid tissue lymphoma, an arachnoid cyst, and a lipochoristoma. None of these rare tumors could be identified before surgery. Three operative approaches were used: the retrosigmoid approach, middle fossa subtemporal approach, or translabyrinthine approach. Few complications occurred, including facial nerve palsy, loss of hearing, and vestibular function. Five-year average follow-up revealed one patient with recurrence. Conclusions Clinical examination and imaging alone were insufficient to correctly identify these tumors. Definitive pathologicdiagnosis should be strongly considered to help tailor treatment.

Glossopharyngeal, nervus intermedius, and vagus neuralgias can all present with ear pain. However, to our knowledge, there have been no reports of otalgia as the only symptom of vagus neuralgia. The seventh, ninth, and tenth cranial nerves have many interneural connections, and the exact anatomy and pathophysiology of these neuralgias are often not clear. Moreover, symptoms due to involvement of any of these nerves can be difficult to attribute solely to 1 of them. The overlapping sensory innervation of the external auditory canal can lead to misdiagnosis in patients suffering from otalgia. This report presents a case of pure otalgia due to vascular compression of the vagus nerve (VN) and considers the microanatomic differences between glossopharyngeal and nervus intermedius neuralgia via cadaveric dissections. We report 2 cases of external auditory canal pain that continued following microvascular treatment of trigeminal neuralgia. Intraoperatively and at secondary operation, the posterior inferior cerebellar artery was found to be adherent and to penetrate between the fibers of the VN. Following microvascular treatment of the VN, the pain resolved. Conclusion This is the first report of vagus neuralgia presenting solely with ear pain. Surgeons should be aware that primary external auditory canal pain can be due to vagus neuralgia via its auricular branch and that such patients can be misdiagnosed with glossopharyngeal or nervus intermedius neuralgias.

There are no definitive treatment guidelines for caval-filter thrombosis in the postoperative setting. Clinical management for partial or complete postoperative inferior vena cava (IVC) occlusion relies solely on expert opinion, anecdotal evidence, and small clinical trials. As such, the primary objective of the present report is to offer a complex case of extensive IVC filter occlusion in a neurosurgical patient with past medical history significant for protein C deficiency. The presentation, unique radiological findings, management, and outcome will be discussed. No similar cases of massive IVC-occlusive disease in a thrombophilic patient early in the postoperative course following neurosurgical intervention are documented in the medical literature.

Objective To review retrospectively experience with stent-assisted coiling of ophthalmic segment internal carotid artery (ICA) aneurysms to report outcome data and identify the rate of associated visual complications. Methods The Duke endovascular database was retrospectively reviewed to identify all ICA aneurysms treated with stent-assisted embolization between November 2002 and October 2009. Only aneurysms arising from the ophthalmic segment of the ICA and originating from the paraophthalmic or suprasellar variant superior hypophyseal artery were included. These aneurysms have the potential to create visual disturbances related to mass effect on the optic nerve or chiasm or to disrupt the ophthalmic artery. Chart review was performed to obtain clinical information, immediate incidence, and follow-up of aneurysm remnants and any visual complications. Results There were 63 aneurysms (48 paraophthalmic and 15 suprasellar variant superior hypophyseal) identified in 57 patients. The ophthalmic artery was preserved in all but two (3.5%) cases, neither of which resulted in visual deficits. One (1.8%) patient experienced transient acute visual disturbances, and two (3.5%) patients had delayed, persistent deficits. Conclusions Stent-assisted embolization of ophthalmic segment ICA aneurysms is technically achievable and in our series did not appear to result in increased visual complications compared with coil embolization alone or surgical treatment.

Background: A primary focus of hospital treatment following admission for subarachnoid haemorrhage (SAH) is a prevention of cerebral artery vasospasm, which may result in ischaemic stroke. Intraventricular catheter (IVC) insertion to facilitate cerebral spinal fluid (CSF) drainage and intracranial pressure (ICP) monitoring may reduce the incidence or severity of vasospasm, but insufficient evidence exists from which clinicians may determine the best practice of CSF management. Aims: The aim of this study was to provide the pilot data to explore the impact of different methods of CSF drainage on outcomes in patients with SAH. Methods: In this non-randomized observational study, patients diagnosed with SAH who had ICP monitoring in situ were prospectively enrolled. Group assignment was determined by the method of external ventricular drainage (EVD) management prescribed by the attending physician prior to enrollment. Results: The 37 subjects were disproportionately divided: open-EVD group (N = 24) and monitor-ICP group (N = 13). There were no statistically significant differences by group assignment with respect to vasospasm, length of stay (LOS), highest average ICP, total CSF drained and disability upon discharge between groups. Conclusions: Although not significant, our results show that the monitor-ICP group trended towards improved clinical outcomes. These results provide sufficient equipoise to support further research in ICP management in patients with SAH using a randomized clinical trial. Relevance to clinical practice: This study provides a solid foundation for the development of a randomized trial exploring two different methods of ICP monitoring and CSF diversion during the acute phase of care following aneurysm rupture.

Background Intracranial stents have expanded endovascular therapy to wide neck aneurysms whose dimensions and configurations are not amendable to coil embolization alone. Stents however have not eliminated all problems due to technical factors with their delivery systems. The Neuroform stent system is one of the most widely used for this purpose and has undergone several technical modifications to improve deliverability. Despite improvements in the delivery system there are still reports of failure of stent deployment with the Neuroform 3. Here a simple back table modification is described in which the stent is pushed several centimeters back into the delivery catheter from its manufactured location. This makes the catheter tip more flexible and in our experience improves navigation through vessel curvature and increases deployment rate. Methods Our institution9s cerebrovascular database was reviewed retrospectively in compliance with institutional review board approval to identify all Neuroform 3 stents used for assistance with aneurysm embolization since the current stent design became clinically available. Records were reviewed to identify cases of failure of stent placement using the above described technical modification. Results 139 Neuroform 3 stents were placed at our institution for assistance with aneurysm embolization with the technique described above. Only three instances of failure of stent placement related to trackability of the delivery system were identified for a technical failure rate of 2.2%. Conclusions A simple back table modification to the Neuroform 3 delivery system is described which in our single center experience may improve trackability and ultimately successful stent deployment.

Object Inadvertent catheterization of brachiocephalic arteries (carotid artery, subclavian artery, or vertebral artery) during attempted placement of a central venous catheter can have potentially disastrous complications. While removal of the catheter in the operating room is almost always an option, there are circumstances in which a less invasive approach may be more appropriate. The authors present their experience using endovascular techniques for removal of inadvertently placed central venous catheters to elucidate potential options for successful nonsurgical management. Methods The authors reviewed their database of interventional procedures that occurred between January 1, 2000, and February 1, 2009. All cases referred for management of suspected brachiocephalic arterial catheterization or arterial injury after attempted placement of a central venous catheter were included. Medical records and radiological imaging were reviewed to determine patient demographics, clinical situation, methods for removal, as well as clinical and imaging follow-up. Results A total of 13 patients, ranging in age from 31 to 88 years old, were referred to interventional radiology for management of suspected inadvertent arterial catheterization of the brachiocephalic arteries. Angiography confirmed arterial catheterization in 9 patients. Three patients were referred after developing uncontrolled hemorrhage or expanding hematomas following attempted catheterization. One patient who had an arterial waveform after placement of an internal jugular catheter was found to have early venous filling from a dialysis fistula requiring no intervention. Ten patients were treated in the interventional suite using angiographically monitored manual pressure (1 patient), balloon tamponade (3 patients), use of a percutaneous closure device (1 patient), stent grafting (4 patients), or embolization of the injured vessel alone (1 patient). One patient was taken to the operating room for removal of the inadvertently placed catheter due to vessel thrombosis. No procedural complications were encountered, and no patient required sacrifice of a major brachiocephalic vessel. Conclusions Angiographic evaluation of patients who underwent inadvertent catheterization of brachiocephalic arteries or their branches allowed successful endovascular treatment or excluded the need for intervention in 12 (92%) of 13 patients. The choice and use of specific endovascular techniques should be dictated by patient factors and the vessel inadvertently catheterized.

Background Transient adenosine-induced asystole is a reliable method for producing a short period of relative hypotension during surgical and endovascular procedures. Although the technique has been described in the endovascular treatment of brain arteriovenous malformations, aortic aneurysms, and posterior circulation cerebral aneurysms, little description of its use in anterior circulation aneurysms is available. Objective To assess the benefits of adenosine-induced transient asystole in complex anterior circulation aneurysms, to describe our experience in selected cases, and to provide the first experience of the use of adenosine in anterior circulation aneurysms. Methods The adenosine-induced cardiac arrest protocol allows us to titrate the duration of cardiac arrest on the basis of individual patient responses. The operative setup is the same as with all aneurysm clippings, with the addition of the placement of transcutaneous pacemakers as a precaution for prolonged bradycardia or asystole. Escalating doses of adenosine are given to determine the approximate dose that results in 30 seconds of asystole. When requested by the surgeon, the dose of adenosine is administered for definitive dissection and clipping. We present 6 cases in which this technique was used. Results The use of transient adenosine-induced asystole provided excellent circumferential visualization of the aneurysm neck and safe clip application. All patients did well neurologically and suffered no evidence of perioperative cerebral ischemia or delayed complication from the use of adenosine itself. Conclusion Transient adenosine-induced asystole is a safe and effective technique in select circumstances that may aid in safe and effective aneurysm clipping. Along with the traditional techniques of brain relaxation, skull base approaches, and temporary clipping, adenosine-induced asystole facilitates circumferential visualization of the aneurysm neck and is another technique available to cerebrovascular surgeons.

Neurosurgery is one of the most technically demanding and liable of all medical professionals. More than 75% of neurosurgical errors are deemed as preventable and technical in nature. Yet in a specialty that requires such high level of technical expertise, with large consequences for error, there are even fewer opportunities for residents in training to practice on the most complicated cases. Although there is no replacement for actual experiences in the operating room, interpersonal mentorship, coaching, and training, there is room to supplement residency education through simulation. Here we review the evidence to support surgical simulation, describe the strengths and weaknesses of existing technologies in direct neurosurgery specific and indirect simulation applications, and advocate for the development of more neurosurgery-specific applications using emerging kinetic technologies.

Objective:To determine if preoperative lumbar drain (LD) use reduces the incidence of postoperative cerebrospinal fluid (CSF) leak in patients undergoing acoustic neuroma resection.Methods:Retrospective review of 282 patients presenting for acoustic neuroma resection between 2005 and 2014.Results:Two hundred and eighty-two patients had a mean tumor size of 19.1 mm ± 10.2 mm. Twenty-nine (10.3%) patients developed a postoperative CSF leak. Two hundred and twenty patients (78.0%) received a preoperative LD, and 20 (9.1%) developed a CSF leak. Sixty-two (22.0%) patients did not receive a preoperative LD, and 9 (14.5%) developed a CSF leak. No significant difference in CSF leak frequency was observed with use versus no use of a LD ( P = .23). Fifteen (5.3%) patients with an LD placed had a complication related to the LD. No significant difference in CSF leak frequency was observed with patient age, neurofibromatosis type-2 diagnosis, tumor size, or sidedness.Conclusions:Postoperative CSF leaks are among the most common complications of acoustic neuroma microsurgery. No formal guidelines exist for elective placement of a preoperative LD to lower the incidence of CSF leaks. Our reported CSF leak incidence with preoperative LD placement is not significantly lower than without LD use, and there is a complication rate associated with LD use.

Increasing numbers of patients with vestibular schwannoma (VS) have been treated with focused-beam stereotactic radiation treatment (SRT) including Gamma knife, CyberKnife, X-knife, Novalis, or proton beam therapy. The purpose of this study was to document the incidence of tumor regrowth or symptoms that worsened or first developed following SRT and to discuss surgical strategies for patients who have failed SRT for VS. A consecutive series of 39 patients with SRT failed VS were surgically treated. Clinical symptoms, tumor regrowth at follow-up, intraoperative findings, and surgical outcome were evaluated. There were 15 males and 24 females with a mean age of 51.8 years. Thirty-six patients (92.3%) demonstrated steady tumor growth after SRT. Two (5.1%) patients with slight increase of the mass underwent surgical resection because of development of unbearable facial pain. Symptoms that worsened or newly developed following SRT in this series were deafness (41%), dizziness (35.9%), facial numbness (25.6%), tinnitus (20.5%), facial nerve palsy (7.7%), and facial pain (7.7%). Intraoperative findings demonstrated fibrous changes of the tumor mass, cyst formation, and brownish-yellow or purple discoloration of the tumor capsule. Severe adhesions between the tumor capsule and cranial nerves, vessels, and the brainstem were observed in 69.2%. Additionally, the facial nerve was more fragile and irritable in all cases. Gross total resection (GTR) was achieved in 33.3% of patients, near-total resection (NTR) in 35.9%, and subtotal resection (STR) in 30.8% of patients. New facial nerve palsy was seen in seven patients (19.4%) postoperatively. Our findings suggest that patients with VS who fail SRT with either tumor progression or worsening of clinical symptoms will have an increased rate of adhesions to the neurovascular structures and may have radiation-influenced neuromalacia. Salvage surgery of radiation-failed tumors is more difficult and will have a higher risk of postoperative complications. Radical total resection may not be feasible, and conservative modality of subtotal resection needs to be considered to avoid new neurologic deficits.

Background Intraoperative intravascular volume expansion with hydroxyethyl starch-based colloids is thought to be associated with an increased risk of post-craniotomy hemorrhage. Evidence for this association is limited. Associations between resuscitation with hydroxyethyl starch and risk of repeat craniotomy for hematoma evacuation were examined. Methods Using a retrospective cohort of neurosurgical patients at Duke University Medical Center between March 2005 and March 2012, patient characteristics were compared between those who developed post-craniotomy hemorrhage and those who did not. Results A total of 4,109 craniotomy procedures were analyzed with 61 patients having repeat craniotomy for post-operative hemorrhage (1.5%). The rate of reoperation in the group receiving 6% High Molecular Weight Hydroxyethyl Starch (Hextend®) was 2.6 vs. 1.3% for patients that did not receive hetastarch (P = 0.13). The reoperation rate for those receiving 6% hydroxyethyl Starch 130/0.4 (Voluven®) was 1.4 vs. 1.6% in patients not receiving Voluven (P = 0.85). Conclusions In this retrospective cohort, intra-operative hydroxyethyl starch was not associated with an increased risk of post-craniotomy hemorrhage.

Large cerebral aneurysms of the basilar apex are difficult to treat. Recently, endovascular treatment has mitigated much of the morbidity associated with treating these lesions. However, the morphology of aneurysms of the vertebrobasilar system can preclude endovascular treatment. Rapid ventricular pacing (RVP) facilitates open surgical treatment of cerebral aneurysms. It can assist in reducing the pressure of the neck of the aneurysm, allowing safe application of a clip. The authors present a case of a pediatric patient who developed a basilar artery pseudoaneurysm that required surgery. Given the large size of the aneurysm, RVP was performed, allowing the surgeons to dissect the dome of the aneurysm from the surrounding tissue and pontine perforating branches away from the lesion to safely clip the lesion. The patient had an uneventful recovery. To the authors' knowledge, this represents the first known case of RVP to aid in basilar artery clip occlusion in a pediatric patient.