Neurosurgery Blog

Neurosurgery 70:312–319, 2012 DOI: 10.1227/NEU.0b013e318230966f

The quoted risk of hemorrhage from dural arteriovenous fistulae with cortical venous reflux varies widely, and the influence of angiographic grade on clinical course has not previously been reported.

OBJECTIVE: To assess the risk of hemorrhage and the influence of angiographic grade on this risk, compared with known predictors of hemorrhage such as presentation.

METHODS: Seventy-five fistulae with cortical venous reflux identified in our arteriovenous malformations clinic between 1992 and 2007 were followed up clinically, and their angiograms were reviewed.

RESULTS: There were 8 hemorrhages in 90 years of follow-up. The annual incidence of hemorrhage before any treatment was 13%, and 4.7% after partial treatment, giving an overall incidence of 8.9% before definitive treatment. Borden and Cognard grades were poor discriminators of risk for lesions with the exception of Cognard type IV lesions. These lesions, characterized by venous ectasia, had a 7-fold increase in the incidence of hemorrhage (3.5% no ectasia vs 27% with ectasia). Patients presenting with hemorrhage (20%) or nonhemorrhagic neurological deficit (22%) had a higher incidence of hemorrhage than those with a benign presentation (4.3%), but this may be directly linked to the presence of venous ectasia.

CONCLUSION: In this series untreated dural arteriovenous fistulae with cortical venous reflux had a 13% annual incidence of hemorrhage after diagnosis. There was a significant difference between those with and without venous ectasia. This should be confirmed by further studies, but probably defines a high-risk subgroup of patients that requires rapid intervention.

Neurosurgery 70:141–149, 2012 DOI: 10.1227/NEU.0b013e31822ec19e

Giant perimedullary arteriovenous fistulas (GPMAVFs) located in the cervical region are a rare pathology with distinctive characteristics.

OBJECTIVE: To evaluate clinical presentation and different endovascular treatment options of cervical GPMAVFs and review previously published data in the literature regarding cervical GPMAVFs.

METHODS: Six patients with cervical GPMAVFs were found in the spinal vascular malformations database of our group collected between 1990 and 2009. Endovascular techniques and treatment outcomes were evaluated and compared with other published series.

RESULTS: Clinical presentations were progressive motor deficit (5 patients), hematomyelia (1 patient), meningeal syndrome (1 patient), and respiratory arrest and gait apraxia (1 patient). Three patients were treated by the transarterial approach. One patient was treated by the transvenous approach due to previous embolizations resulting in a proximal occlusion and preventing a safe transarterial approach. A transvenous approach was used in another patient due to complex arterial anatomy. In 1 patient, direct percutaneous puncture of the venous pouch was necessary because of previous proximal occlusion of the arteries. All embolizations resulted in complete occlusions with clinical improvement, and there was no recanalization during a mean follow-up of 21 months.

CONCLUSION: Transarterial embolization of cervical GPMAVFs is safe and effective when it is done in highly experienced centers. Cervical GPMAVFs that cannot be accessed by the transarterial technique due to their complex angioarchitecture can be treated by transvenous embolization or direct puncture of the venous pouch.

Neurosurgery 70:125–130, 2012 DOI: 10.1227/NEU.0b013e31822ea02a

Despite its accessible superficial location, the indication for surgical evacuation in cases of lobar intracerebral hemorrhage (LICH) suspected to be related to cerebral amyloid angiopathy (CAA) is controversial because of advanced patient age and concerns about postoperative hemostasis.

OBJECTIVE: To examine factors associated with postoperative outcome in CAA-related LICH.

METHODS: Review of consecutive patients with pathologically proven CAA who underwent LICH evacuation at Saint Marys Hospital, Rochester, Minnesota, between 1987 and 2006. End points were length of stay and postoperative outcome at discharge and last follow-up using the Glasgow Outcome Scale. We also performed a systematic review of all published studies evaluating the outcome of surgically treated CCA-related LICH published between 1984 and 2010.

RESULTS: We identified 23 patients with CAA-related LICH treated surgically. Favorable outcome (Glasgow Outcome Scale .3) at discharge was noted in 5 patients (22%), and at 6- to 12-month follow-up (n = 15) in 7 patients (47%). Three (13%) died in the hospital, including 1 of 4 patients with postoperative hemorrhage. Intraventricular hemorrhage (IVH) was associated with poor outcome at discharge. Older age ($75 years), history of hypertension, and degree of preoperative midline shift were associated with more prolonged length of stay. In our systematic review, we identified 14 studies including 278 cases. Overall mortality rate was 25%, and poor postoperative outcome was associated with older age, IVH, and preoperative dementia.

CONCLUSION: Neurosurgical evacuation may be performed with acceptable safety in patients with CAA-related LICH. A systematic literature review indicates that older age, preexistent dementia, and presurgical IVH portend poor postoperative outcome.

J Neurosurg 116:157–163, 2012. DOI: 10.3171/2011.8.JNS11324

The authors sought to identify the presence of a “July effect,” a transient increase in adverse outcomes during July, among a cohort of spontaneous subarachnoid hemorrhage (SAH) admissions recorded in the National Inpatient Sample (NIS).

Methods. The discharge status, admission month, patient demographics, treatment parameters, and hospital characteristics among spontaneous SAH admissions were extracted from the 2001–2008 NIS. Multivariate regression was used to determine whether an unfavorable discharge status and/or in-hospital mortality significantly increased in summer months in a pattern suggestive of a July effect. Additional models were generated to assess the impact of hospital teaching status on these outcomes.

Results. Among 57,663,486 hospital admissions from the 2001–2008 NIS, 52,879 cases of spontaneous SAH (ICD-9-CM 430) were treated at teaching (36,914 cases [70%]) and nonteaching (15,965 cases [30%]) facilities. Regression models failed to reveal a July effect for in-hospital mortality (c2 = 0.75, p = 1.000) or unfavorable discharges (c2 = 1.69, p = 0.999) among monthly SAH admissions, although they did suggest a significant reduction in these outcomes (in-hospital mortality, OR = 0.89, p < 0.001; unfavorable discharges, OR = 0.88, p < 0.001) among teaching hospitals as compared with nonteaching hospitals after adjustment for disparities in demographic, treatment, and hospital characteristics.

Conclusions. The discharge disposition among SAH admissions within the NIS was not suggestive of a July effect but did reveal that teaching institutions have significantly lower rates of adverse outcomes when compared with nonteaching hospitals. Note, however, that the origins of this difference related to teaching status remain unclear.

J Neurosurg 116:54–65, 2012. DOI: 10.3171/2011.9.JNS11177

The object of this study was to define the long-term outcomes and risks of arteriovenous malformation (AVM) management using 2 or more stages of stereotactic radiosurgery (SRS) for symptomatic large-volume lesions unsuitable for surgery.

Methods. In 1992, the authors prospectively began to stage the treatment of anatomical components to deliver higher single doses to AVMs with a volume of more than 10 cm3. Forty-seven patients with such AVMs underwent volume-staged SRS. In this series, 18 patients (38%) had a prior hemorrhage and 21 patients (45%) underwent prior embolization. The median interval between the first-stage SRS and the second-stage SRS was 4.9 months (range 2.8–13.8 months). The median target volume was 11.5 cm3 (range 4.0–26 cm3) in the first-stage SRS and 9.5 cm3 in the second-stage SRS. The median margin dose was 16 Gy (range 13–18 Gy) for both stages.

Results. In 17 patients, AVM obliteration was confirmed after 2–4 SRS procedures at a median follow-up of 87 months (range 0.4–209 months). Five patients had near-total obliteration (volume reduction > 75% but residual AVM). The actuarial rates of total obliteration after 2-stage SRS were 7%, 20%, 28%, and 36% at 3, 4, 5, and 10 years, respectively. The 5-year total obliteration rate after the initial staged volumetric SRS with a margin dose of 17 Gy or more was 62% (p = 0.001). Sixteen patients underwent additional SRS at a median interval of 61 months (range 33–113 months) after the initial 2-stage SRS. The overall rates of total obliteration after staged and repeat SRS were 18%, 45%, and 56% at 5, 7, and 10 years, respectively. Ten patients sustained hemorrhage after staged SRS, and 5 of these patients died. Three of 16 patients who underwent repeat SRS sustained hemorrhage after the procedure and died. Based on Kaplan-Meier analysis (excluding the second hemorrhage in the patient who had 2 hemorrhages), the cumulative rates of AVM hemorrhage after SRS were 4.3%, 8.6%, 13.5%, and 36.0% at 1, 2, 5, and 10 years, respectively. This corresponded to annual hemorrhage risks of 4.3%, 2.3%, and 5.6% for Years 0–1, 1–5, and 5–10 after SRS. Multiple hemorrhages before SRS correlated with a significantly higher risk of hemorrhage after SRS. Symptomatic adverse radiation effects were detected in 13% of patients, but no patient died as a result of an adverse radiation effect. Delayed cyst formation did not occur in any patient after SRS.

Conclusions. Prospective volume-staged SRS for large AVMs unsuitable for surgery has potential benefit but often requires more than 2 procedures to complete the obliteration process. To have a reasonable chance of benefit, the minimum margin dose should be 17 Gy or greater, depending on the AVM location. In the future, prospective volumestaged SRS followed by embolization (to reduce flow, obliterate fistulas, and occlude associated aneurysms) may improve obliteration results and further reduce the risk of hemorrhage after SRS.

Neurosurgery 70:49–55, 2012 DOI: 10.1227/NEU.0b013e31822cb979

The excimer laser–assisted nonocclusive anastomosis (ELANA) technique enables large-caliber bypass revascularization without temporary occlusion of the parent artery.

OBJECTIVE: To present the surgical experience of 2 bypass centers using ELANA in the treatment of complex intracranial lesions.

METHODS: Between July 2002 and December 2007, 64 consecutive patients (37 in Germany and 27 in Finland) were selected for high-flow bypass surgery with ELANA. Modified Rankin Scale, a bypass success rate, and the success rate of the laser arteriotomy were assessed.

RESULTS: In 66 surgeries for 64 intent-to-treat patients, 58 ELANA procedures were completed successfully. A favorable outcome (postoperative modified Rankin Scale score less than or equal to preoperative modified Rankin Scale) at 3 months was achieved in 43 of 56 patients (77%) with anterior circulation lesions (37 of the 43 patients had aneurysms, 4 had ischemia, and 2 received a bypass before tumor removal) and only in 2 of 8 patients (25%) with posterior circulation aneurysms. Perioperative (, 7 days) mortality for anterior and posterior circulation aneurysms was 6% and 50%, respectively. At the 3-month follow-up, 12% and 63% of patients with anterior and posterior circulation aneurysms, respectively, were dead. The success rate of the laser arteriotomy was 70%. Another 14% were retrieved manually after a nearly complete laser arteriotomy.

CONCLUSION: The ELANA procedure requires a meticulous and careful operative technique. Morbidity and especially mortality rates, usually unrelated to ELANA, are comparable to those of contemporary series of conventional high-flow revascularization operations. This underscores the overall complexity of treating neurovascular pathologies by high-flow bypasses.

Neurosurg Focus 32 (1):E5, 2012. 10.3171/2011.10.FOCUS11251

Sonothrombolysis has recently been considered an emerging modality for the treatment of stroke. The purpose of the present paper was to review randomized clinical studies concerning the effects of sonothrombolysis associated with tissue plasminogen activator (tPA) on acute ischemic stroke.

METHODS

Systematic searches for literature published between January 1996 and July 2011 were performed for studies regarding sonothrombolysis combined with tPA for acute ischemic stroke. Only randomized controlled trials were included. Data extraction was based on ultrasound variables, patient characteristics, and outcome variables (rate of intracranial hemorrhages and arterial recanalization).

RESULTS

Four trials were included in this study; 2 trials evaluated the effect of transcranial Doppler (TCD) ultrasonography on sonothrombolysis, and 2 addressed transcranial color-coded duplex (TCCD) ultrasonography. The frequency of ultrasound waves varied from 1.8 to 2 MHz. The duration of thrombus exposure to ultrasound energy ranged from 60 to 120 minutes. Sample sizes were small, recanalization was evaluated at different time points (60 and 120 minutes), and inclusion criteria were heterogeneous. Sonothrombolysis combined with tPA did not lead to an increase in symptomatic intracranial hemorrhagic complications. Two studies demonstrated that patients treated with ultrasound combined with tPA had statistically significant higher rates of recanalization than patients treated with tPA alone.

CONCLUSIONS

Despite the heterogeneity and the limitations of the reviewed studies, there is evidence that sonothrombolysis associated with tPA is a safe procedure and results in an increased rate of recanalization in the setting of acute ischemic stroke when wave frequencies and energy intensities of diagnostic ultrasound systems are used.

J Neurosurg 116:135–144, 2012.DOI: 10.3171/2011.8.JNS101767

The purpose of this ongoing study is to compare the safety and efficacy of microsurgical clipping and endovascular coil embolization for the treatment of acutely ruptured cerebral aneurysms and to determine if one treatment is superior to the other by examining clinical and angiographic outcomes. The authors examined the null hypothesis that no difference exists between the 2 treatment modalities in the setting of subarachnoid hemorrhage (SAH). The current report is limited to the clinical results at 1 year after treatment.

Methods. The authors screened 725 patients with SAH, resulting in 500 eligible patients who were enrolled prospectively in the study after giving their informed consent. Patients were assigned in an alternating fashion to surgical aneurysm clipping or endovascular coil therapy. Intake evaluations and outcome measurements were collected by nurse practitioners independent of the treating surgeons. Ultimately, 238 patients were assigned to aneurysm clipping and 233 to coil embolization. The 2 treatment groups were well matched. There were no anatomical exclusions. Crossing over was allowed, but primary outcome analysis was based on the initial treatment modality assignment. Posttreatment care was standardized for both groups. Patient outcomes at 1 year were independently assessed using the modified Rankin Scale (mRS). A poor outcome was defined as an mRS score > 2 at 1 year. The primary outcome was based on the assigned group; that is, by intent to treat.

Results. One year after treatment, 403 patients were available for evaluation. Of these, 358 patients had actually undergone treatment. The remainder either died before treatment or had no identifiable source of SAH. A poor outcome (mRS score > 2) was observed in 33.7% of the patients assigned to aneurysm clipping and in 23.2% of the patients assigned to coil embolization (OR 1.68, 95% CI 1.08–2.61; p = 0.02). Of treated patients assigned to the coil group, 124 (62.3%) of the 199 who were eligible for any treatment actually received endovascular coil embolization. Patients who crossed over from coil to clip treatment fared worse than patients assigned to coil embolization, but no worse than patients assigned to clip occlusion. No patient treated by coil embolization suffered a recurrent hemorrhage.

Conclusions. One year after treatment, a policy of intent to treat favoring coil embolization resulted in fewer poor outcomes than clip occlusion. Although most aneurysms assigned to the coil treatment group were treated by coil embolization, a substantial number crossed over to surgical clipping. Although a policy of intent to treat favoring coil embolization resulted in fewer poor outcomes at 1 year, it remains important that high-quality surgical clipping be available as an alternative treatment modality.

Acta Neurochir (2012) 154:33–41. DOI 10.1007/s00701-011-1209-9

Epidemiological studies indicate a link between low-dose irradiation (<10,000 mGy) to the head and the local occurrence of tumors after decades of delay. Comparable radiation doses can be reached during neuroendovascular procedures (NEP), but the incidence of similar exposures has not been completely delineated. We compared the levels of radiation to the head measured during NEP to those reported for patients developing radiation-induced cancers.

Methods In our prospective study we determined the cumulative maximum entrance skin doses (MESD) and the incidence of epilation in 107 consecutive patients submitted to NEP between 2003 and 2007. We also extensively searched the literature and compared our results with the data we found.

Results The cumulative MESD due to NEP was above 3,000 mGy (range 3,101–5,421 mGy) in 18 patients. In 22 we observed partial epilation within 10 weeks from the initial NEP. Sixty cases of epilation after NEP have been previously reported in the literature. The average of the reported MESD was 4,241 mGy (range 2,000–6,640 mGy).

Conclusion Physical dosimetry and the incidence of partial epilation indicate that about one fifth of the patients submitted to NEP received radiation doses comparable to those linked to the occurrence of tumors. The potential risks of developing tumors after a long delay, when compared to the immediate benefits of endovascular treatment of aneurysm and arteriovenous malformations (AVM) of the brain, do not counterindicate NEP, but increased awareness of the risk should help physicians and patients to make a fully informed decision when other treatments are available.

J Neurosurg 115:1169–1174, 2011. DOI: 10.3171/2011.7.JNS11536

Seizures are the most common presenting symptom of supratentorial cerebral cavernous malformations (CCMs) and progress to medically refractory epilepsy in 40% of patients. Predictors of seizure freedom in the resection of CCMs are incompletely understood.

Methods. The authors systematically reviewed the published literature on seizure freedom following the resection of supratentorial CCMs in patients presenting with seizures. Seizure outcomes were stratified across 12 potential prognostic variables. A total of 1226 patients with supratentorial CCMs causing seizures were identified across 31 predominantly retrospective studies; 361 patients had medically refractory epilepsy.

Results. Seventy-five percent of the patients were seizure free after microsurgical lesion removal, whereas 25% continued to have seizures. All patients had had preoperative seizures and > 6 months of postoperative follow-up. Modifiable predictors of postoperative seizure freedom included gross-total resection (OR 36.6, 95% CI 8.5–157.5) and surgery within 1 year of symptom onset (OR 1.83, 95% CI 1.30–2.58). Additional prognostic indicators of a favorable outcome were a CCM size < 1.5 cm (OR 15.4, 95% CI 5.2–45.4), the absence of multiple CCMs (OR 2.02, 95% CI 1.13–3.60), medically controlled seizures (OR 2.38, 95% CI 1.29–4.39), and the lack of secondarily generalized seizures (OR 3.33, 95% CI 2.09–5.30). Other factors, including extended resection of the hemosiderin ring, were not significantly predictive.

Conclusions. In the surgical treatment of supratentorial CCMs, gross-total resection and early operative intervention may improve seizure outcome. While surgery should not be considered the first-line treatment for CCM-related epilepsy, it is important to understand the variables associated with seizure freedom in CCM resection given the considerable morbidity and diminished quality of life associated with epilepsy.

Neurosurg Focus 31 (6):E4, 2011. DOI: 10.3171/2011.9.FOCUS11237

The management of incidental small unruptured intracranial aneurysms (UIAs) is controversial and many factors need to be considered in the decision-making process. The authors describe a large consecutive series of patients harboring small incidental intracranial aneurysms. Treatment strategy, natural history, complications, and short-term outcomes are presented.

Methods. Between January 2008 and May 2011, the authors prospectively evaluated 212 patients with 272 small (< 10-mm) incidental aneurysms. Treatment recommendations (observation, endovascular treatment, or surgery), complications of treatment, and short-term outcomes were assessed.

Results. Recommended treatment consisted of observation in 125 patients, endovascular embolization in 64, and surgery in 18. Six patients were excluded from further analysis because they underwent treatment elsewhere. In the observation group, at a mean follow-up of 16.7 months, only 1 patient was moved to the embolization group. Seven (6%) of the 125 patients in the observation group died of causes unrelated to aneurysm. Sixty-five patients underwent 69 embolization procedures. The periprocedural permanent morbidity and mortality rates in patients undergoing endovascular treatment were 1.5% and 1.5%, respectively (overall morbidity and mortality rate 3.0%). In the surgery group no periprocedural complications were observed, although 1 patient did not return to her previous occupation. No aneurysmal rupture was documented in any of the 3 treatment groups during the follow-up period.

Conclusions. A cautious and individualized approach to incidental UIAs is of utmost importance for formulation of a safe and effective treatment algorithm. Invasive treatment (either endovascular or surgery) can be considered in selected younger patients, certain “higher-risk” locations, expanding aneurysms, patients with a family history of aneurysmal hemorrhage, and in those who cannot live their lives knowing that they harbor the UIA. Although the complication rate of invasive treatment is very low, it is not negligible. The study confirms that small incidental UIAs deemed to be not in need of treatment have a very benign short-term natural history, which makes observation a reasonable approach in selected patients.

J Neurosurg Spine 15:654–659, 2011. DOI: 10.3171/2011.8.SPINE11155

Digital subtraction (DS) angiography is the gold standard for diagnosing spinal vascular malformations. Recently, multidetector-row spiral CT and contrast-enhanced MR angiography have been introduced as screening examinations before DS angiography. These methods, however, do not always determine the accurate location of an arteriovenous shunt because the resulting images lack information about the spinal cord or the dura mater.

Methods. Between April 2009 and December 2010, 13 patients underwent imaging evaluations for spinal vascular malformations at the authors’ university hospital. This group included 8 patients with spinal dural arteriovenous fistulas (AVFs), 3 with perimedullary AVFs, and 2 with intramedullary arteriovenous malformations. Using data from these patients, the authors attempted to develop 3D computer graphics (CG) based upon the fusion of 3D rotational angiography and postmyelographic CT. They subsequently verified the accuracy of this imaging method. Ten of these 13 patients underwent surgical treatment for their lesions (11 AVFs), and for these 11 lesions the authors compared the diagnoses obtained using 3D CG with those obtained using conventional DS angiography.

Results. In all 13 cases, 3D CG images of the spinal lesions were successfully developed using the patients’ actual data. Four (36%) of 11 AVFs were correctly identified using DS angiography, whereas 10 (91%) were correctly identified using 3D CG. Results from 3D CG of spinal AVFs corresponded well with operative findings, and 3D CG was significantly better than conventional DS angiography at predicting AVF location (p = 0.024, Fisher exact test).

Conclusions. To the authors’ knowledge, this is the first reported case series in which 3D CG of spinal vascular malformations was used to provide simultaneous, stereoscopic visualization of the spinal vascular system, spinal cord, dura mater, and bone. The 3D CG method provides precise visual images for the diagnosis and treatment of these lesions.

Neurosurgery 69:1261–1271, 2011 DOI: 10.1227/NEU.0b013e31822bb8a6

Many significant microsurgical series of patients with giant aneurysms predate changes in practice during the endovascular era.

OBJECTIVE: A contemporary surgical experience is presented to examine changes in management relative to earlier reports, to establish the role of open microsurgery in the management strategy, and to quantify results for comparison with evolving endovascular therapies.

METHODS: During a 13-year period, 140 patients with 141 giant aneurysms were treated surgically. One hundred aneurysms (71%) were located in the anterior circulation, and 41 aneurysms were located in the posterior circulation.

RESULTS: One hundred eight aneurysms (77%) were completely occluded, 14 aneurysms (10%) had minimal residual aneurysm, and 16 aneurysms (11%) were incompletely occluded with reversed or diminished flow. Three patients with calcified aneurysms were coiled after unsuccessful clipping attempts. Eighteen patients died in the perioperative period (surgical mortality, 13%). Bypass-related complications resulted from bypass occlusion (7 patients), aneurysm hemorrhage due to incomplete aneurysm occlusion (4 patients), or aneurysm thrombosis with perforator or branch artery occlusion (4 patients). Thirteen patients were worse at late follow-up (permanent neurological morbidity, 9%; mean length of follow-up, 23 6 1.9 months). Overall, good outcomes (Glasgow Outcome Score 5 or 4) were observed in 114 patients (81%), and 109 patients (78%) were improved or unchanged after therapy.

CONCLUSION: A heavy reliance on bypass techniques plus indirect giant aneurysm occlusion distinguishes this contemporary surgical experience from earlier ones, and obviates the need for hypothermic circulatory arrest. Experienced neurosurgeons can achieve excellent results with surgery as the ‘‘first-line’’ management approach and endovascular techniques as adjuncts to surgery.

Acta Neurochir (2011) 153:2119–2125. DOI 10.1007/s00701-011-1129-8

Nicardipine prolonged release implants (NPRI) have been shown to decrease the incidence of cerebral vasospasm and infarcts significantly in patients after aneurysmal subarachnoid haemorrhage (SAH) follow- ing microsurgical clipping. Yet, the comparison with results after endovascular coiling is lacking. This study was conducted to determine the differences in the incidence of cerebral vasospasm and infarctions between those two treatment modalities

Methods The design of this investigation reflects a case- control study; 27 patients suffering from acute SAH were treated by microsurgical clipping and received an intracisternal implantation of NPRI. Twenty-seven matching consecutive patients after microsurgical treatment without implantation of NPRI or endovascular treatment, respectively, served as controls. The incidence of angiographic vasospasm and cerebral infarctions were documented.

Results All groups were comparable concerning demographics and severity of SAH. Twenty-four of 81 patients developed angiographic vasospasm (>33% constriction). The incidence of vasospasm was 48%, 44% and 11% for patients after endovascular treatment, microsurgical clipping without NPRI and microsurgical clipping with NPRI, respectively. New cerebral infarctions occurred in 28%, 22% and 7% of the treated patients, respectively. A good clinical recovery 1 year after the initial bleeding (modified Rankin scale 0–2) was seen in 48%, 50% and 77% of the treated patients, respectively.

Conclusion The use of NPRI during microsurgical clipping was confirmed to be safe and effective. Patients who received intracisternally implanted NPRI during clipping after aneurysmal SAH yielded significantly lower vasospasm and infarction rates, and showed a better clinical outcome when compared with clipping without NPRI and also when compared with endovascular coiling.

Neurosurgery 69:1105–1115, 2011 DOI: 10.1227/NEU.0b013e318227e0e1

In patients with aneurysmal subarachnoid hemorrhage (SAH), preliminary results indicate that the amplitude of the single intracranial pressure (ICP) wave is a better predictor of the early clinical state and 6-month outcome than the mean ICP.

OBJECTIVE: To perform a randomized and blinded single-center trial comparing the effect of mean ICP vs mean ICP wave amplitude (MWA)-guided intensive care management on early clinical state and outcome in patients with aneurysmal SAH.

METHODS: Patients were randomized to 2 different types of ICP management: maintenance of mean ICP less than 20 mm Hg and MWA less than 5mm Hg. Early clinical state was assessed daily using the Glasgow Coma Scale. The primary efficacy variable was 12-month outcome in terms of the Rankin Stroke Score.

RESULTS: Ninety-seven patients were included in the study. There were no significant differences in treatment between the 2 groups apart from a larger volume of cerebrospinal fluid drained during week 1 in the MWA group. There was a tendency toward higher Glasgow Coma Scale scores in the MWA group during weeks 1 (P = .08) and 2 (P = .07). Outcome in terms of Rankin Stroke Score at 12 months was significantly better in the MWA group (P < .05).

CONCLUSION: This randomized and blinded trial disclosed a significant better primary efficacy variable (Rankin Stroke Score after 12 months) in the MWA patient group. We suggest that proactive intensive care management with MWA-tailored cerebrospinal fluid drainage during the first week improves aneurysmal SAH outcome.

Acta Neurochir (2011) 153:2181–2187. DOI 10.1007/s00701-011-1141-z

In cerebral arteriovenous malformations (AVMs) detailed intraoperative identification of feeding arteries, nidal vessels and draining veins is crucial for surgery.

Intraoperative imaging techniques like indocyanine green videoangiography (ICG-VAG) provide information about vessel architecture and patency, but do not allow time-dependent analysis of intravascular blood flow.

Here we report on our first experiences with analytical indocyanine green videoangiography (aICG-VAG) using FLOW 800 software as a useful tool for assessing the time-dependent intraoperative blood flow during surgical removal of cerebral AVMs. Microscope-integrated colour-encoded aICG-VAG was used for the surgical treatment of a 38-year-old woman diagnosed with an incidental AVM, Spetzler Martin grade I, of the left frontal lobe and of a 26-year-old man suffering from seizures caused by a symptomatic AVM, Spetzler Martin grade III, of the right temporal lobe. Analytical ICG-VAG visualization was intraoperatively correlated with in situ micro-Doppler investigation, as well as preoperative and postoperative digital subtraction angiography (DSA).

Analytical ICG-VAG is fast, easy to handle and integrates intuitively into surgical procedures. It allows colour-encoded visualization of blood flow distribution with high temporal and spatial resolution. Superficial major and minor feeding arteries can be clearly separated from the nidus and draining veins. Effects of stepwise vessel obliteration on velocity and direction of AVM blood flow can be objectified. High quality of visualization, however, is limited to the site of surgery. Colour-encoded aICG-VAG with FLOW 800 enables intraoperative real-time analysis of arterial and venous vessel architecture and might, therefore, increase efficacy and safety of neurovascular surgery in a selected subset of superficial AVMs.

Acta Neurochir (2011) 153:2103–2109. DOI 10.1007/s00701-011-1171-6

The management of complex paraclinoid aneurysms is still challenging. In this article we describe our approach to paraclinoid aneurysms, which has evolved over several years, using an exclusively intradural approach.

Method All procedures are done under continuous electrophysiological monitoring. A standard pterional approach is used to access the paraclinoid region exclusively intraduraly. After optic nerve unroofing and tailored clinoidectomy, the aneurysm neck is visualized and clipped using the tandem clipping technique and suction decompression if necessary. Aneurysm occlusion is verified using intraoperative ICG angiography and postoperative 3D DSA.

Conclusion The exclusively intradural approach to complex paraclinoid aneurysms with tailored clinoidectomy offers an excellent surgical corridor for the treatment of these challenging lesions

Journal of Neurosurgery Oct 2011 / Vol. 115 / No. 4 / Pages 700-706

For oculomotor nerve palsy (ONP) induced by unruptured posterior communicating artery (PCoA) aneurysms, the authors performed surgical clipping via a superciliary keyhole approach as an optimal treatment modality with high efficiency and low invasiveness. In this study, they then evaluated the technical feasibility, safety, clinical outcomes, including recovery from ONP as well as cosmetic results, and durability of the procedure.

METHODS Thirteen patients presenting with complete (7 patients) or incomplete (6 patients) ONP underwent surgery via a superciliary approach. The operative video record was used to evaluate the technical feasibility, neurological examinations and CT were performed to analyze the safety of the treatment, and neuroophthalmological examinations and 3D CT angiography were undertaken to determine the effectiveness and durability of the treatment.

RESULTS In all cases, the aneurysms were successfully clipped using a 3.5-cm eyebrow incision and supraorbital minicraniotomy. The mean operative time was 108 ± 24 minutes. Twelve (92.3%) of the 13 patients showed complete resolution of the ONP. All 6 patients (100%) with incomplete ONP recovered completely within 1–2 months after surgery, whereas 6 (85.7%) of the 7 patients with complete ONP recovered completely within 1–6 months after surgery. Cosmetic results for the operative wounds were excellent without frontalis palsy. The durability of the treatment was ascertained based on 3D CT angiograms obtained 1 year after surgery.

CONCLUSIONS Surgical clipping via a superciliary keyhole approach can be an optimal treatment modality for PCoA aneurysms inducing ONP because it is effective, safe, and durable.

Neurosurg Rev DOI 10.1007/s10143-011-0349-y

Chronic subdural hematoma (cSDH) is an increasingly common neurological disease process. Despite the wide prevalence of cSDH, there remains a lack of consensus regarding numerous aspects of its clinical management. We provide an overview of the epidemiology and pathophysiology of cSDH and discuss several controversial management issues, including the timing of postoperative resumption of anticoagulant medications, the effectiveness of anti-epileptic prophylaxis, protocols for mobilization following evacuation of cSDH, as well as the comparative effectiveness of the various techniques of surgical evacuation.

A PubMed search was carried out through October 19, 2010 using the following keywords: “subdural hematoma”, “craniotomy”, “burr-hole”, “management”, “anticoagulation”, “seizure prophylaxis”, “antiplatelet”, “mobilization”, and “surgical evacuation”, alone and in combination. Relevant articles were identified and back-referenced to yield additional papers. A meta-analysis was then performed comparing the efficacy and complications associated with the various methods of cSDH evacuation.

There is general agreement that significant coagulopathy should be reversed expeditiously in patients presenting with cSDH. Although protocols for gradual resumption of anti-coagulation for prophylaxis of venous thrombosis may be derived from guidelines for other neurosurgical procedures, further prospective study is necessary to determine the optimal time to restart fulldose anti-coagulation in the setting of recently drained cSDH. There is also conflicting evidence to support seizure prophylaxis in patients with cSDH, although the existing literature supports prophylaxis in patients who are at a higher risk for seizures.

The published data regarding surgical technique for cSDH supports primary twist drill craniostomy (TDC) drainage at the bedside for patients who are high-risk surgical candidates with non-septated cSDH and craniotomy as a first-line evacuation technique for cSDH with significant membranes. Larger prospective studies addressing these aspects of cSDH management are necessary to establish definitive recommendations.