Category: Vascular

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Recurrence of Cerebral Arteriovenous Malformations Following Resection in Adults: Does Preoperative Embolization Increase the Risk?

Recurrence of Cerebral Arteriovenous Malformations Following Resection in Adults- Does Preoperative Embolization Increase the Risk?

Neurosurgery 78:562–571, 2016

Complete surgical resection of arteriovenous malformations (AVMs), documented by postoperative angiography, is generally felt to represent cure, obviating the need for long-term follow-up imaging. Although AVM recurrence has been reported in the pediatric population, this phenomenon has only rarely been documented in adults. Recurrence after treatment solely with embolization, however, has been reported more frequently. Thus, patients undergoing multimodal therapy with surgery following preoperative embolization may also be at higher risk for recurrence.

OBJECTIVE: To determine if preoperative embolization contributes to recurrences of AVMs after complete surgical resection.

METHODS: A retrospective study of patients undergoing AVM resection was performed. Those with complete surgical AVM resection, confirmed by negative early postoperative cerebral angiography and with available follow-up angiographic imaging .6 months postoperatively were included.

RESULTS: Two hundred three patients underwent AVM resection between 1995 and 2012. Seventy-two patients met eligibility criteria. There were 3 recurrences (4%). Deep venous drainage and diffuse type of AVM nidus were significantly associated with recurrence. Although preoperative embolization did not reach statistical significance as an independent risk factor, radiographic data supported its role in every case, with the site of recurrence correlating with deep regions of nidus previously obliterated by embolization.

CONCLUSION: AVM recurrences in the adult population may have a multifactorial origin. Although deep venous drainage and diffuse nidus are clearly risk factors, preoperative embolization may also be a contributing factor with the potential for recurrence of unresected but embolized portions of the AVM. Follow-up angiography at 1 to 3 years appears to be warranted.

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Association of Hemodynamic Factors With Intracranial Aneurysm Formation and Rupture

Association of Hemodynamic Factors With Intracranial Aneurysm Formation and Rupture

Neurosurgery 78:510–520, 2016

Recent evidence suggests a link between the magnitude and distribution of hemodynamic factors and the formation and rupture of intracranial aneurysms. However, there are many conflicting results.

OBJECTIVE: To quantify the effect of hemodynamic factors on aneurysm formation and their association with ruptured aneurysms.

METHODS: We performed a systematic review and meta-analysis through October 2014. Analysis of the effects of hemodynamic factors on aneurysm formation was performed by pooling the results of studies that compared geometrical models of intracranial aneurysms and “preaneurysm” models where the aneurysm was artificially removed. Furthermore, we calculated pooled standardized mean differences between ruptured and unruptured aneurysms to quantify the association of hemodynamic factors with ruptured aneurysms. Standard PRISMA guidelines were followed.

RESULTS: The hemodynamic factors that showed high positive correlations with location of aneurysm formation were high wall shear stress (WSS) and high gradient oscillatory number, with pooled proportions of 78.8% and 85.7%, respectively. Positive correlations were largely seen in bifurcation aneurysms, whereas negative correlations were seen in sidewall aneurysms. Mean and normalized WSS were significantly lower and low shear area significantly higher in ruptured aneurysms.

CONCLUSION: Pooled analyses of computational fluid dynamics models suggest that an increase in WSS and gradient oscillatory number may contribute to aneurysm formation, whereas low WSS is associated with ruptured aneurysms. The location of the aneurysm at the bifurcation or sidewall may influence the correlation of these hemodynamic factors.

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Ideal clipping methods for unruptured middle cerebral artery bifurcation aneurysms based on aneurysmal neck classification

MCAb aneurysms clipping

Neurosurg Rev (2016) 39:215–224

Endovascular coiling is widely used for many cerebral aneurysms; however, in cases of middle cerebral artery bifurcation (MCBIF) aneurysms, it is associated with a higher incidence of unfavorable outcomes compared to microsurgical clippings. In this retrospective study, we aimed to investigate the outcomes of microsurgical clipping for unruptured MCBIF aneurysms and determine the ideal clipping methods for different aneurysm subtypes.

From January 2011 to December 2013, 203 aneurysms with saccular shape (<25 mm) were treated by an experienced neurosurgeon. Depending on the involvement of the aneurysmal thin wall, the aneurysm neck was classified as follows: subtype I, limited bifurcation; subtype II, progressed to M1 trunk; subtype III, progressed to M2 trunk; subtype IV, progressed to M1 and one M2 trunk; and subtype V, progressed to M1 and two M2 trunks. The clipping methods included simple, sliding, interlocking, or mixed approaches.

Aneurysm clippings were accomplished without any morbidity in all cases, and seven cases had a minimal neck remnant. The following clipping methods were predominantly used: subtype I, simple (90.2 %) and sliding (8.8 %) (mean = 1.2 clips); subtype II, interlocking (51.4 %), sliding (30.0 %), mixed (15.7 %), and simple (2.9 %) (2.4 clips); subtype III, simple (57.5 %) and sliding (42.5 %) (1.5 clips); subtype IV, interlocking (64.3 %) (2.1 clips), simple (10.7 %), sliding (14.3 %), and mixed (10.7 %); and subtype V, interlocking (50.0 %), sliding (35.7 %), and mixed (14.3 %) methods with multiple clips (2.8 clips).

If an appropriate clipping method is selected according to the neck classification, satisfactory surgical obliteration can be achieved for unruptured MCBIF aneurysms without morbidity.

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Stereotactic Radiosurgery for Arteriovenous Malformations: The Effect of Treatment Period on Patient Outcomes

AVM

Neurosurgery 78:499–509, 2016

Stereotactic radiosurgery (SRS) has been performed on patients with cerebral arteriovenous malformations (AVMs) for over 40 years.

OBJECTIVE: To evaluate the impact of treatment period on obliteration, intracranial hemorrhage (ICH), and radiation-induced complications (RICs).

METHODS: Retrospective comparison of 381 AVM patients having SRS during a 20-year period (group 1, January 1990 through March 1997, n = 160; group 2, April 1997 through December 2009, n = 221). The median radiological and clinical follow-up after initial SRS was 77 months and 93 months, respectively.

RESULTS: Obliteration was 59.1% at 4 years and 85.1% at 8 years. Obliteration was more common in patients with hemispheric or cerebellar AVMs (P = .001), smaller prescription isodose volume (PIV) (P < .001), and group 1 patients (P < .001). The ICH rate was 7.7% at 4 years and 10.6% at 8 years. ICH was more common in older patients (P = .02), patients with deep AVM (P = .01), and larger PIV (P < .001). There was no difference in the ICH rate between the treatment groups (P = .18). The rate of permanent RICs was 4.4% at 4 years and 8.6% at 8 years. RICs were more common with larger PIVs (P < .001) and group 1 patients (P = .02). There was no difference in the number of patients having obliteration without new deficits between the 2 treatment periods (68.8% vs 73.3%, P = .33).

CONCLUSION: Advances in SRS procedures over the past 20 years have resulted in a lower risk of RIC, but fewer patients had AVM obliteration. Increasing the prescription dose for patients with medium- and large-volume AVMs by using current conformal dose-planning techniques may improve the obliteration rate while maintaining a low risk of RICs.

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Comparison of Outcome Between Surgical and Conservative Management of Symptomatic Spinal Cord Cavernous Malformations

Comparison of Outcome Between Surgical and Conservative Management of Symptomatic Spinal Cord Cavernous Malformations

Neurosurgery 78:552–561, 2016

Intramedullary cavernous malformations (CMs) are rare lesions with unclear natural history.

OBJECTIVE: To compare the functional outcomes of spinal CMs managed surgically and conservatively.

METHODS: We performed a retrospective study of patients diagnosed with intramedullary CMs seen at our institution from 2006 to 2013. Functional outcomes of patients were assessed by treatment modality with the Modified McCormick Scale and Karnofsky Performance Status.

RESULTS: We identified a total of 85 study-eligible patients; 51 (60.0%) were male. Mean age of patients was 40.5 years. Fifty-eight patients underwent microsurgical removal, and 27 patients underwent conservative management. All patients except 1 harbored a single symptomatic intramedullary CM. Mean follow-up time was 42.8 months. For the surgical group (n = 58), 51 CMs were completely resected. During the follow-up period, 40 patients (69.0%) within the surgical group had improvement in neurological state, 16 patients (27.6%) remained unchanged, and 2 patients (3.4%) experienced deteriorated functional status. In the conservative group, 4 patients (14.8%) had improvement of their symptoms, 19 patients (70.4%) remained in baseline, and 4 patients (14.8%) deteriorated. No significant statistical difference was observed in followup Karnofsky Performance Status assessment (odds ratio = 0.89; 95% confidence interval = 0.73-1.08; P = .15) or Modified McCormick Scale assessment (odds ratio = 0.90; 95% confidence interval = 0.74-1.10; P = .30) after adjustment for preoperative lesion size and location. Annual hemorrhagic risk was 3.9% in conservatively managed patients. In contrast, no patients experienced subsequent hemorrhages after surgical resection.

CONCLUSION: Surgical resection of intramedullary CMs eliminates the risk of subsequent hemorrhagic and may achieve satisfactory outcome when patients are carefully selected. Although conservative management is recommended in patients at high surgical risk, they should be closely monitored because of persistent hemorrhagic risk.

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Microembolism after endovascular coiling of unruptured cerebral aneurysms: incidence and risk factors

Microembolism after endovascular coiling of unruptured cerebral aneurysms

J Neurosurg 124:777–783, 2016

The incidence and risk factors of microembolic lesions on MR diffusion-weighted imaging (DWI) were analyzed after the endovascular coiling of unruptured intracranial aneurysms (UIAs).

Methods Data obtained from 271 consecutive patients (70 men and 201 women; median age 57 years; range 23–79 years) who presented with UIA for coil embolization between July 2011 and June 2013 were analyzed. Two independent reviewers examined the DWI and apparent diffusion coefficient maps obtained the following day for the presence of restrictive diffusion spots and counted the number of spots. Multivariate analysis was then performed to identify independent risk factors for developing microembolism following the coiling of an aneurysm.

Results Microembolic lesions were noted in 101 of 271 patients (37.3%). The results of the multivariate analysis showed that the following factors significantly influenced the risk for microembolism: age, diabetes, previous history of ischemic stroke, high-signal FLAIR lesions in the white matter, multiple aneurysms, and the insertion of an Enterprise stent (all ORs > 1.0 and all p values < 0.05). Previously known risk factors such as prolonged procedure duration, aneurysm size, and decreased antiplatelet function did not show any significant influence.

Conclusions The incidence of microembolism after endovascular coiling of UIA was not low. Lesions occurred more frequently in patients with vascular status associated with old age, diabetes, and previous stroke. Aneurysm multiplicity and the type of stent used for treatment also influenced lesion occurrence.

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Height of aneurysm neck and estimated extent of brain retraction: powerful predictors of olfactory dysfunction after surgery for unruptured anterior communicating artery aneurysms

Height of aneurysm neck and estimated extent of brain retraction- powerful predictors of olfactory dysfunction after surgery for unruptured anterior communicating artery aneurysms

J Neurosurg 124:720–725, 2016

The highest incidence of olfactory dysfunction following a pterional approach and its modifications for an intracranial aneurysm has been reported in cases of anterior communicating artery (ACoA) aneurysms. The radiological characteristics of unruptured ACoA aneurysms affecting the extent of retraction of the frontal lobe and olfactory nerve were investigated as risk factors for postoperative olfactory dysfunction.

Methods A total of 102 patients who underwent a pterional or superciliary keyhole approach to clip an unruptured ACoA aneurysm from 2006 to 2013 were included in this study. Those patients who complained of permanent olfactory dysfunction after their aneurysm surgery, during a postoperative office visit or a telephone interview, were invited to undergo an olfactory test, the Korean version of the Sniffin’ Sticks test. In addition, the angiographic characteristics of ACoA aneurysms, including the maximum diameter, the projecting direction of the aneurysm, and the height of the neck of the aneurysm, were all recorded based on digital subtraction angiography and sagittal brain images reconstructed using CT angiography. Furthermore, the extent of the brain retraction was estimated based on the height of the ACoA aneurysm neck.

Results Eleven patients (10.8%) exhibited objective olfactory dysfunction in the Sniffin’ Sticks test, among whom 9 were anosmic and 2 were hyposmic. Univariate and multivariate analyses revealed that the direction of the ACoA aneurysm, ACoA aneurysm neck height, and estimated extent of brain retraction were statistically significant risk factors for postoperative olfactory dysfunction. Based on a receiver operating characteristic (ROC) analysis, an ACoA aneurysm neck height > 9 mm and estimated brain retraction > 12 mm were chosen as the optimal cutoff values for differentiating anosmic/hyposmic from normosmic patients. The values for the area under the ROC curves were 0.939 and 0.961, respectively.

Conclusions In cases of unruptured ACoA aneurysm surgery, the height of the aneurysm neck and the estimated extent of brain retraction were both found to be powerful predictors of the occurrence of postoperative olfactory dysfunction.

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Long-term outcomes after surgical and endovascular treatment of spinal dural arteriovenous fistulae

SDAVF

Eur Spine J (2016) 25:748–754

To examine the validity of our treatment strategy for spinal dural arteriovenous fistulae (SDAVF), based on the treatment results and the long-term outcome.

Methods This study included 50 SDAVF patients (38 men, 12 women, mean age 63.2 years) with progressive myelopathy. The treatment strategy involved embolization as the initial management tool and surgery if embolization was considered unsuitable. Their medical records were evaluated to identify the treatment results and functional outcomes. The mean follow-up period was 81.2 months (range 27–184 months).

Results Complete obliteration was achieved in 22 (71.0 %) of 31 embolized patients and in 18 of 19 (94.7 %) operated patients. The initial success rate was significantly lower in embolized than operated patients. At the last follow-up, 33 of the 50 patients (66 %) manifested im- proved gait and 16 (32 %) improved micturition. The ac- tivity of daily living (ADL) was improved in 33 (66 %). When we compared the rates of functional improvement at the last follow-up, there was no significant difference be- tween patients treated initially by embolization or surgery.

Conclusions The long-term outcomes in SDAVF patients treated by multidisciplinary management with first-line embolization were comparable to those in earlier surgical series. However, our results were unable to demonstrate the superiority of endovascular embolization to surgical treatment for SDAVF. For the purpose of justifying endovascular embolization as a first-line treatment for SDAVF, it will be necessary to show further improvement in both the initial treatment success and the complication rates.

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Endoscopic endonasal clip ligation of cerebral aneurysms

Endoscopic endonasal clip ligation of cerebral aneurysms

J Neurosurg 124:463–468, 2016

The expansion of endovascular procedures for obliteration of cerebral aneurysms highlights one of the drawbacks of clip ligation through the transcranial route, namely brain retraction or brain transgression. Sporadic case reports have emerged over the past 10 years describing endonasal endoscopic clip ligation of cerebral aneurysms. The authors present a detailed anatomical study to evaluate the feasibility of an endoscopic endonasal approach for application of aneurysm clips.

Methods Nine human cadaveric head specimens were used to evaluate operative exposures for clip ligation of aneurysms in feasible anterior and posterior circulation locations. Measurements of trajectories were completed using a navigation system to calculate skull base craniectomy size, corridor space, and the surgeon’s ability to gain proximal and distal control of parent vessels.

Results In each of the 9 cadaveric heads, excellent exposure of the target vessels was achieved. The transplanum, transtuberculum, and transcavernous approaches were used to explore the feasibility of anterior circulation access. Application of aneurysm clips was readily possible to the ophthalmic artery, A1 and A2 segments of the anterior cerebral artery, anterior communicating artery complex, and the paraclinoid and paraclival internal carotid artery. The transclival approach was explored, and clips were successfully deployed along the proximal branches of the vertebrobasilar system and basilar trunk and bifurcation. The median sizes of skull base craniectomy necessary for exposure of the anterior communicating artery complex and basilar tip were 3.24 cm2 and 4.62 cm2, respectively. The mean angles of surgical corridors to the anterior communicating artery complex and basilar tip were 11.4° and 14°, respectively. Although clip placement was feasible on the basilar artery and its branches, the associated perforating arteries were difficult to visualize, posing unexpected difficulty for safe clip application, with the exception of ventrolateral-pointing aneurysms.

Conclusions The authors characterize the feasibility of endonasal endoscopic clip ligation of aneurysms involving the paraclinoid, anterior communicating, and basilar arteries and proximal control of the paraclival internal carotid artery. The endoscopic approach should be initially considered for nonruptured aneurysms involving the paraclinoid and anterior communicating arteries, as well as ventrolateral basilar trunk aneurysms. Clinical experience will be mandatory to determine the applicability of this approach in practice.

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Predictors of Poor Quality of Life 1 Year After Subarachnoid Hemorrhage

A Simple and Quantitative Method to Predict Symptomatic Vasospasm After Subarachnoid Hemorrhage Based on Computed Tomography- Beyond the Fisher Scale

Neurosurgery 78:256–264, 2016

Risk factors for poor quality of life (QOL) after subarachnoid hemorrhage (SAH) remain poorly described.

OBJECTIVE: To identify the frequency and predictors of poor QOL 1 year after SAH.

METHODS: We studied 1-year QOL in a prospectively collected cohort of 1181 consecutively admitted SAH survivors between July 1996 and May 2013. Patient clinical, radiographic, surgical, and acute clinical course information was recorded. Reduced QOL (overall, physical, and psychosocial) at 1 year was assessed with the Sickness Impact Profile and defined as 2 SD below population-based normative Sickness Impact Profile values. Logistic regression leveraging multiple imputation to handle missing data was used to evaluate reduced QOL.

RESULTS: Poor overall QOL was observed in 35% of patients. Multivariable analysis revealed that nonwhite ethnicity, high school education or less, history of depression, poor clinical grade (Hunt-Hess Grade $3), and delayed infarction were predictors of poor overall and psychosocial QOL. Poor physical QOL was additionally associated with older age, hydrocephalus, pneumonia, and sepsis. At 1 year, patients with poor QOL had increased difficulty concentrating, cognitive dysfunction, depression, and reduced activities of daily living. More than 91% of patients with poor QOL failed to fully return to work. These patients frequently received physical rehabilitation, but few received cognitive rehabilitation or emotional-behavioral support.

CONCLUSION: Reduced QOL affects as many as one-third of SAH survivors 1 year after SAH. Delayed infarction is the most important in-hospital modifiable factor that affects QOL. Increased attention to cognitive and emotional difficulties after hospital discharge may help patients achieve greater QOL.

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Hemodynamic response during aneurysm clipping surgery among experienced neurosurgeons

surgery_aneurysm

Acta Neurochir (2016) 158:221–227

Neurosurgery is a challenging field associated with high levels of mental stress. The goal of this study was to investigate the hemodynamic response of experienced neurosurgeons during aneurysm clipping surgery and to evaluate whether neurosurgeons’ hemodynamic responses are associated with patients’ clinical statuses.

Methods Four vascular neurosurgeons (all male; mean age 51 ± 10 years; post-residency experience ≥7 years) were studied during 42 aneurysm clipping procedures. Blood pressure (BP) and heart rate (HR) were assessed at rest and during seven phases of surgery: before the skin incision, after craniotomy, after dural opening, after aneurysm neck dissection, after aneurysm clipping, after dural closure and after skin closure.

Results HR and BP were significantly greater during surgery relative to the rest situation (p≤ 0.03). There was a statistically significant increase in neurosurgeons’ HR (F [6, 41] = 10.88, p <0.001), systolic BP (F [6, 41] =2.97, p =0.01), diastolic BP (F [6, 41] = 2.49, p = 0.02) and mean BP (F [6, 41] = 3.36, p = 0.003) during surgery. The greatest mean HR was after aneurysm clipping, and the greatest BP was after aneurysm neck dissection. Systolic, diastolic and mean BPs were significantly greater during surgical clipping for unruptured aneurysms compared to ruptured aneurysms across all stages of surgery (p ≤ 0.002); however, after adjusting for neurosurgeon experience, the difference in BP as a function of aneurysm rupture was not significant (p>0.08). Aneurysm location, intraoperative aneurysm rupture, admission WFNS score, admission Glasgow Coma Scale scores and Fisher grade were not associated with neurosurgeons’ intraoperative HR and BP (all p > 0.07).

Conclusions Aneurysm clipping surgery is associated with significant hemodynamic system activation among experienced neurosurgeons. The greatest HR and BP were after aneurysm neck dissection and clipping. Aneurysm location and patient clinical status were not associated with intraoperative changes of neurosurgeons’ HR and BP.

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A Reappraisal of Anterior Communicating Artery Aneurysms: A Case for Stent-Assisted Embolization

Anterior Communicating Artery Aneurysms- A Case for Stent-Assisted Embolization

Neurosurgery 78:200–207, 2016

Wide-necked anterior communicating artery aneurysms represent a subset of lesions with challenging endovascular treatment despite new endoluminal and intrasaccular devices.

OBJECTIVE: To assess the long-term clinical and angiographic outcomes of stentassisted embolization for wide-necked anterior communicating artery aneurysms.

METHODS: Between March 2008 and March 2014, 32 patients with unruptured widenecked AComm aneurysms were treated using stent-assisted embolization. The Glasgow Outcome Scale was reviewed at the time of discharge and at latest follow-up. Ischemic and hemorrhagic events were also recorded and analyzed. Aneurysm occlusion was evaluated post-intervention and on subsequent follow-up evaluations.

RESULTS: Successful stent deployment was achieved in all cases, but in 1 patient the coils could not be contained inside the aneurysm, and the procedure was aborted without complications. The distal segment of the stent was positioned in the ipsilateral A2 in 16 patients, in the contralateral A2 in 15 patients, and in the contralateral A1 in 1 patient. There were no periprocedural thromboembolic or hemorrhagic complications. The rate of major complications was 6%. One patient developed intracranial hemorrhage related to antiplatelet therapy and another had ischemic events due to in-stent stenosis. Angiographic follow-up was available for 26 aneurysms and during a mean follow-up of 22 months, 81% of the lesions were completely occluded and 8% had a small residual neck. The retreatment rate for residual aneurysms was 3%.

CONCLUSION: Our long-term results suggest that stent-assisted embolization for anterior communicating artery aneurysms may be considered an excellent treatment option with an adequate combination of safety profile and effectiveness.

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Determining Surgical Approaches to Basilar Bifurcation Aneurysms

Determining Surgical Approaches to Basilar Bifurcation Aneurysms

Neurosurgery 78:181–191, 2016

The basilar bifurcation aneurysm (BBA) is still considered to be one of the most challenging aneurysms for micro- and endovascular surgery. Classic surgical approaches, such as subtemporal, lateral supraorbital (LSO), and modified presigmoid, are still reliable and effective.

OBJECTIVE: To analyze the clinical and radiological factors that affect the selection of these classic surgical approaches and their outcomes.

METHODS: A retrospective analysis was conducted on the clinical and radiological data from computed tomographic angiography of BBA that have been clipped in the Department of Neurosurgery of Helsinki University Central Hospital between 2004 and 2014. Statistical analyses were performed using parametric and nonparametric tests where values were considered significant below P = .05.

RESULTS: One hundred four patients with BBA underwent surgical clipping in our department between 2004 and 2014. Eight patients were excluded from the study because of incomplete preoperative radiological evaluations, leaving 96 patients for further analysis. Multiple aneurysm clipping, mean basilar bifurcation angle, and aneurysm neck distance from posterior clinoid process were shown to be factors that determine the surgical approach. Unfavorable outcome is strongly associated with poor Hunt-Hess grade on admission, distance from aneurysm neck (the posterior clinoid process), thrombosis, and dome size.

CONCLUSION: Microsurgery for BBA clipping can be performed safely with simple surgical approaches: subtemporal and LSO. There are several factors determining the approach selected. Poor patient outcome in BBA was highly associated with poor preoperative clinical grade and large size of aneurysm dome.

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Endovascular Management of Deep Arteriovenous Malformations

Endovascular management AVM

Neurosurgery 78:34–41, 2016

The management of arteriovenous malformations (AVMs) in the basal ganglia, insula, and thalamus is demanding for all treatment modalities.

OBJECTIVE: To define safety and outcomes of embolization used as a stand-alone therapy for deep-seated AVMs.

METHODS: A cohort of 22 patients with AVMs located in the basal ganglia, thalamus, and insula who underwent embolization between January 2008 and December 2013.

RESULTS: Eighteen of 22 (82%) patients had anatomic exclusion. The mean size was 2.98 6 1.28 cm, and the mean number of sessions was 2.1 per patient. Most patients presented with hemorrhage (82%, n = 18), and 3 (14%) patients were in a deteriorated neurological status (modified Rankin Scale .2) at presentation. Sixty-eight percent of ruptured AVMs had size #3 cm. A single transarterial approach was performed in 9 (41%) cases, double catheterization was used in 4 (18%), and the transvenous approach was required in 8 (36%) cases. Procedure-related complications were registered in 3 (14%) cases. One death was associated with treatment, and complementary radiosurgery was required in 2 (9%) patients.

CONCLUSION: Embolization therapy appears to be safe and potentially curative for certain deep AVMs. Our results demonstrate a high percentage of anatomic obliteration with rates of complications that may approach radiosurgery profile. In particular, embolization as stand-alone therapy is most suitable to deep AVMs with small nidus size (#3 cm) and/or associated with single venous drainage in which microsurgery might not be indicated.

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Continuous cisternal irrigation with Mg solution for vasospasm

Mg sulfate irrigation

J Neurosurg 124:18–26, 2016

Although cerebral vasospasm (CV) is one of the most important predictors for the outcome in patients with subarachnoid hemorrhage (SAH), no treatment has yet been established for this condition. This study investigated the efficacy of continuous direct infusion of magnesium sulfate (MgSO4) solution into the intrathecal cistern in patients with an aneurysmal SAH.

Methods An SAH caused by a ruptured aneurysm was identified on CT scans within 72 hours after SAH onset. All patients were treated by surgical clipping and randomized into 2 groups: a control group of patients undergoing a standard treatment and a magnesium (Mg) group of patients additionally undergoing continuous infusion of 5 mmol/L MgSO4 solution for 14 days. The Mg2+ concentrations in serum and CSF were recorded daily. Neurological examinations were performed by intensive care clinicians. Delayed cerebral ischemia was monitored by CT or MRI. To assess the effect of the Mg treatment on CV, the CVs were graded on the basis of the relative degree of constriction visible on cerebral angiograms taken on Day 10 after the SAH, and transcranial Doppler ultrasonography was performed daily to measure blood flow velocity in the middle cerebral artery (MCA). Neurological outcomes and mortality rates were evaluated with the Glasgow Outcome Scale and modified Rankin Scale at 3 months after SAH onset.

Results Seventy-three patients admitted during the period of April 2008 to March 2013 were eligible and enrolled in this study. Three patients were excluded because of violation of protocol requirements. The 2 groups did not significantly differ in age, sex, World Federation of Neurosurgical Societies grade, or Fisher grade. In the Mg group, the Mg2+ concentration in CSF gradually increased from Day 4 after initiation of the continuous MgSO4 intrathecal administration. No such increase was observed in the control group. No significant changes in the serum Mg2+ levels were observed for 14 days, and no cardiovascular complications such as bradycardia or hypotension were observed in any of the patients. However, bradypnea was noted among patients in the Mg group. The Mg group had a significantly better CV grade than the control group (p < 0.05). Compared with the patients in the Mg group, those in the control group had a significantly elevated blood flow velocity in the MCA. Both groups were similar in the incidences of cerebral infarction, and the 2 groups also did not significantly differ in clinical outcomes.

Conclusions Continuous cisternal irrigation with MgSO4 solution starting on Day 4 and continuing to Day 14 significantly inhibited CV in patients with aneurysmal SAH without severe cardiovascular complications. However, this improvement in CV neither reduced the incidence of delayed cerebral ischemia nor improved the functional outcomes in patients with SAH.

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Preoperative predictive factors for surgical and functional outcomes in chronic subdural hematoma

Subdural Hematoma

Acta Neurochir (2016) 158:135–139

Chronic subdural hematoma (CSDH) is a frequently encountered neurosurgical condition, especially in the elderly. We investigated predictive factors for surgical and functional outcomes after burr-hole drainage (BHD) surgery.

Methods All patients with CSDH treated by BHD between January 2012 and December 2014 were included in this study. All patients were classified by symptom, clinical grade, time, location, hematoma density, midline shift, and other characteristics. Pre- and postoperative CT evaluation was performed at 0, 3, and 6 months. Clinical grades were classified as described in Markwalder et al. Surgical and clinical outcomes were evaluated with the brain expansion rate and modified Rankin Scale (mRS). Brain expansion rate was calculated as the ratio between post- and pre-operative hematoma thickness. Recurrence was defined as the occurrence of symptoms and hematoma on CT within 6 months.

Results This study included 130 patients over 2 years. Among the variable parameters, young age (<75), iso-density of hematoma on CT, and short duration from symptom to surgery were correlated with good brain expansion. Patients with good brain expansion had fewer recurrences. In terms of mRS, young age, iso-density, and good clinical grade were correlated with good functional outcomes.

Conclusions Clinicians should be more aware of general conditions and medical problems, especially in elderly patients. Membranectomy should be considered in patients with a long duration of symptoms or hypo-dense hematomas to promote good brain expansion and good mRS scores.

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Surgical Clipping of Very Small Unruptured Intracranial Aneurysms

very small aneurysms

Neurosurgery 78:47–52, 2016

Treatment of very small unruptured intracranial aneurysms (VSUIAs, defined as ≤3 mm) can be indicated in selected circumstances. The feasibility and outcomes of endovascular therapy for VSUIAs have been recently published; however, the efficacy and complication rate of surgical clipping has not been reported in any large series to date.

OBJECTIVE: We conducted a multicenter study to examine surgical outcomes for VSUIAs.

METHODS: All consecutive patients undergoing surgery for a VSUIA in 4 neurosurgical centers between October 2001 and December 2012 were retrospectively analyzed.

RESULTS: In the study, 183 patients (128 women, mean age 51.3 years) were treated with 190 procedures for a total of 228 aneurysms. Most were anterior circulation aneurysms (n = 215). The majority were directly clipped (n = 222, 97.4%), with coagulation or wrapping in the remainder. After 1 reoperation for incomplete clipping, postoperative imaging of 225 aneurysms confirmed complete occlusion in 221 (98.2%), 1 neck remnant (0.44%), and 3 partial occlusions (1.3%). Mortality was 0%. Early postoperative neurological deficit developed in 12 patients (6.6%); posterior circulation location was a significant risk factor for early neurological deficit (P < .001). Middle cerebral artery aneurysms had the lowest rate of postoperative deficits at 1.5% (P = .023). After the initial 30-day perioperative period, all deficits related to treatment of posterior circulation aneurysms recovered; overall neurological morbidity decreased to 2.7% with no mortality.

CONCLUSION: VSUIA clipping is highly effective and is associated with a low morbidity rate. For VSUIAs selected for treatment, our data support surgical clipping as the modality of choice.

KEY WORDS:

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Aneurysm location and clipping versus coiling for development of secondary normal-pressure hydrocephalus after aneurysmal subarachnoid hemorrhage

Hydrocephalus

J Neurosurg 123:1555–1561, 2015

The present study aimed to investigate aneurysm locations and treatments for ruptured cerebral aneurysms associated with secondary normal-pressure hydrocephalus (sNPH) after subarachnoid hemorrhage (SAH) by using comprehensive data from the Japanese Stroke DataBank.

Methods Among 101,165 patients with acute stroke registered between 2000 and 2013, 4693 patients (1482 men, 3211 women) were registered as having had an SAH caused by a ruptured saccular aneurysm. Of them, 1448 patients (438 men and 1010 women; mean age 61.9 ± 13.4 years) who were confirmed to have or not have coexisting acute hydrocephalus and sNPH were included for statistical analyses. Locations of the ruptured aneurysms were subcategorized into 1 of the following 4 groups: middle cerebral artery (MCA; n = 354), anterior communicating artery and anterior cerebral artery (ACA; n = 496), internal carotid artery (ICA; n = 402), and posterior circulation (n = 130). Locations of 66 of the ruptured aneurysms were unknown/unrecorded. Treatments included craniotomy and clipping alone in 1073 patients, endovascular coil embolization alone in 285 patients, and a combination of coiling and clipping in 17 patients. The age-adjusted and multivariate odds ratios from logistic regression analyses were calculated after stratification using the Fisher CT scale to investigate the effects of the hematoma volume of SAH.

Results Acute hydrocephalus was confirmed in 593 patients, and 521 patients developed sNPH. Patients with a ruptured ACA aneurysm had twice the risk for sNPH over those with a ruptured MCA aneurysm. Those with an ACA aneurysm with Fisher Grade 3 SAH had a 9-fold-higher risk for sNPH than those with an MCA aneurysm with Fisher Grade 1 or 2 SAH. Patients with a ruptured posterior circulation aneurysm did not have any significant risk for sNPH. Clipping of the ruptured aneurysm resulted in twice the risk for sNPH over coil embolization alone.

Conclusions Patients with low-grade SAH caused by a ruptured MCA aneurysm had a low risk for the development of sNPH. In contrast, patients with high-grade SAH caused by a ruptured ACA aneurysm had a higher risk for sNPH. Endovascular coiling might confer a lower risk of developing sNPH than microsurgical clipping.

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Safety and Efficacy of Surgical Resection of Unruptured Low-grade Arteriovenous Malformations From the Modern Decade

AVM-before

Neurosurgery 77:948–953, 2015

Recent studies have questioned the utility of surgical resection of unruptured brain arteriovenous malformations (bAVMs).

OBJECTIVE: We performed an assessment of outcomes and complications of surgical resection of low-grade bAVMs (Spetzler-Martin grade I or II) at a single high-volume neurosurgical center.

METHODS: We reviewed all unruptured low-grade bAVMs treated with surgery (with or without preoperative embolization) between January 2004 and January 2014. Stroke rate, mortality, and clinical and radiographic outcomes were examined.

RESULTS: Of 95 patients treated surgically, 85 (25 grade I, 60 grade II) met inclusion criteria, and all achieved radiographic cure postoperatively. Ten patients (11.8%) were lost to follow-up; the mean follow-up of the remaining 85 was 3.3 years. Three patients (3.5%) with grade II bAVMs experienced a stroke; no patients died. Although 20 patients (23.5%) had temporary postoperative neurological deficit, only 3 (3.5%) had new clinical impairment (modified Rankin Scale score $2) at last follow-up. Eight of the 13 patients (61.5%) with preexisting clinical impairment had improved modified Rankin Scale scores of 0 or 1; and 17 of 30 patients (56.7%) with preoperative seizures were seizure-free without antiepileptic medication postoperatively. No significant differences existed in stroke rate or clinical outcome between grades I and II patients at follow-up (Fisher exact test, P = .55 and P . .99, respectively).

CONCLUSION: Surgical resection of low-grade unruptured bAVMs is safe, with a high rate of improvement in functional status and seizure reduction. Although transient postoperative neurological deficit was observed in some patients, permanent treatment- related neurological morbidity was rare.

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Resolution of Oculomotor Nerve Palsy Secondary to Posterior Communicating Artery Aneurysms- Comparison of Clipping and Coiling

Advanced Technical Skills Are Required for Microsurgical Clipping of Posterior Communicating Artery Aneurysms in the Endovascular Era-0

Neurosurgery 77:931–939, 2015

Previous studies have attempted to determine the best treatment for oculomotor nerve palsy (ONP) secondary to posterior communicating artery (PCoA) aneurysms, but have been limited by small sample sizes and limited treatment.

OBJECTIVE: To analyze the treatment of ONP secondary to PCoA with both coiling and clipping in ruptured and unruptured aneurysms.

METHODS: Data from 2 large academic centers was retrospectively collected over 22 years, yielding a total of 93 patients with ONP secondary to PCoA aneurysms. These patients were combined with 321 patients from the literature review for large data analyses. Onset symptoms, recovery, and time to resolution were evaluated with respect to treatment and aneurysm rupture status.

RESULTS: For all patients presenting with ONP (n = 414) 56.6% of those treated with microsurgical clipping made a full recovery vs 41.5% of those treated with endovascular coil embolization (P = .02). Of patients with a complete ONP (n = 229), full recovery occurred in 47.3% of those treated with clipping but in only 20% of those undergoing coiling (P = .01). For patients presenting with ruptured aneurysms (n = 130), full recovery occurred in 70.9% compared with 49.3% coiled patients (P = .01). Additionally, although patients with full ONP recovery had a median time to treatment of 4 days, those without full ONP recovery had a median time to treatment of 7 days (P = .01).

CONCLUSION: Patients with ONP secondary to PCoA aneurysms treated with clipping showed higher rates of full ONP resolution than patients treated with coil embolization. Larger prospective studies are needed to determine the true potential of recovery associated with each treatment.

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