Month: February 2013

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Cerebral Aneurysms in Pregnancy and Delivery: Pregnancy and Delivery Do Not Increase the Risk of Aneurysm Rupture

Microsurgical clipping of true posterior communicating

Neurosurgery 72:143–150, 2013

It is not known what effect pregnancy or delivery has on the risk of rupture of an intracranial aneurysm, and, consequently, the optimal management of unruptured aneurysms in pregnancy is unclear.

OBJECTIVE: To study the effect of pregnancy and delivery on the risk of rupture of intracranial aneurysms and to delineate trends in neurosurgical and obstetric management of pregnant women with intracranial aneurysms.

METHODS: The Nationwide Inpatient Sample data were analyzed for years 1988 to 2009 to estimate the risk of aneurysm rupture during pregnancies and deliveries. We calculated the risk by dividing the observed number of patients with ruptured aneurysm during pregnancy and delivery by the expected number based on the incidence among women of pregnancy age.

RESULTS: There were 714 and 172 hospitalizations involving ruptured aneurysms with pregnancy and delivery, respectively. Assuming 1.8% prevalence of unruptured aneurysms among all women of pregnancy age, we estimated that 48 873 women hospitalized for pregnancy and 312 128 women hospitalized for delivery had unruptured aneurysms. The risks of rupture during pregnancy and deliveries were 1.4% (95% confidence interval [CI] = [1.35, 1.57]) and 0.05% (95% CI = [0.0468, 0.0634]), respectively. Of 218 deliveries performed with unruptured aneurysm, 153 were cesarean deliveries (70.18%, 95% CI = [64.06, 76.30%]), suggesting that the rate of cesarean deliveries in patients with unruptured aneurysms is significantly higher than in the general population (P < .001).

CONCLUSION: We were not able to find an increased association between pregnancy or delivery and the risk of rupture of cerebral aneurysms. The significantly higher rate of cesarean deliveries performed in patients with unruptured aneurysms may not be necessary.

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Motion characteristics of the vertebral segments with lumbar degenerative spondylolisthesis in elderly patients

Motion characteristics of the vertebral segments with lumbar degenerative spondylolisthesis in elderly patients

Eur Spine J (2013) 22:425–431

Although some studies have reported on the kinematics of the lumbar segments with degenerative spondylolisthesis (DS), few data have been reported on the in vivo 6 degree-of-freedom kinematics of different anatomical structures of the diseased levels under physiological loading conditions. This research is to study the in vivo motion characteristics of the lumbar vertebral segments with L4 DS during weight-bearing activities.

Methods Nine asymptomatic volunteers (mean age 54.4) and 9 patients with L4 DS (mean age 73.4) were included. Vertebral kinematics was obtained using a combined MRI/ CT and dual fluoroscopic imaging technique. During functional postures (supine, standing upright, flexion, and extension), disc heights, vertebral motion patterns and instability were compared between the two groups.

Results Although anterior disc heights were smaller in the DS group than in the normal group, the differences were only significant at standing upright. Posterior disc heights were significantly smaller in DS group than in the normal group under all postures. Different vertebral motion patterns were observed in the DS group, especially in the left–right and cranial–caudal directions during flexion and extension of the body. However, the range of motions of the both groups were much less than the reported criteria of lumbar spinal instability.

Conclusion The study showed that lumbar vertebra with DS has disordered motion patterns. DS did not necessary result in vertebral instability. A restabilization process may have occurred and surgical treatment should be planned accordingly.

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Glycerol rhizotomy and radiofrequency thermocoagulation for trigeminal neuralgia in multiple sclerosis

Print

J Neurosurg 118:329–336, 2013

Patients with trigeminal neuralgia due to multiple sclerosis (TN-MS) and idiopathic TN (ITN) who underwent glycerol rhizotomy (GR) and radiofrequency thermocoagulation with glycerol rhizotomy (RFTC-GR) were compared to investigate the effectiveness of these percutaneous ablative procedures in the TN-MS population.

Methods. Between 1998 and 2010, 822 patients with typical TN were evaluated; 63 (8%) had TN-MS and 759 (92%) had ITN. Pain relief comparisons were made between 22 GR procedures in patients with TN-MS and 470 GR procedures in patients with ITN; 50 RFTC-GR procedures in patients with TN-MS and 287 RFTC-GR procedures in patients with ITN were compared. Analysis of time to recurrence included only procedures that achieved complete pain relief without medications.

Results. After 15 of the GR procedures (68%) in patients with TN-MS and 315 of the procedures (67%) in those with ITN, the patients were pain free without medications (p = 0.736). After 36 of the RFTC-GR procedures (72%) in patients with TN-MS and 210 of the procedures (73%) in those with ITN, the patients were pain free without medications (p = 0.657). The difference in pain relief between GR and RFTC-GR for patients with TN-MS was not significant (p = 0.447). The median time to failure of GR was 20 months in patients with TN-MS compared with 25 months in those with ITN (p = 0.403). The median time to failure of RFTC-GR was 26 months in the TN-MS population compared with 21 months in the ITN population (p = 0.449). Patients with TN-MS experienced similar times to recurrence whether they were treated with GR or RFTC-GR (p = 0.431).

Conclusions. Pain relief and durability of relief outcomes of GR and RFTC-GR were similar in patients with TN-MS and ITN, reinforcing their use as preferred treatments of TN-MS. The GR and RFTC-GR achieved comparable outcomes in patients with TN-MS, suggesting that both can be used to good effect.

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Revision to an adjustable non-siphon control valve in low pressure hydrocephalus

Low pressure Hydrocephalus

Clinical Neurology and Neurosurgery 115 (2013) 175– 178

High intracranial compliance states requiring negative pressure drainage, otherwise known as low-pressure hydrocephalus syndromes, are rare conditions. The use of siphoning, enabled by revision to an adjustable shunt without an anti-siphon device, has been largely unexplored in low-pressure hydrocephalus.

Methods: Three patients with presumed normal pressure hydrocephalus (NPH) presented with unresolved symptoms, including urinary incontinence, disturbed gait, and cognitive dysfunction. Each was inadequately treated despite confirmed functioning Strata II valves (with built-in siphon control device) calibrated to the lowest pressure setting for maximum drainage. Surgical revision to Strata non-siphon control (NSC) valves was performed to allow for additional drainage via siphoning.

Results: Following revision to a shunt with a “siphoning” device, each patient achieved improved neurological function. Each differential pressure valve was initially set to a higher setting than with the Strata II valve. One of our patients experienced the formation of a subdural hematoma after shunt revision; resolution following adjustment of the valve to a higher setting suggests that siphoning may be of less importance to overdrainage syndromes when compared with valve opening pressure.

Conclusion: Our findings indicate that intermittent intracranial hypotension achieved by siphoning is effective in the treatment of a subset of patients presenting clinically with NPH. Direct conversion to a shunt system without an anti-siphon device allows reduction of ventricular size without the risk associated with external ventricular drainage (EVD). With conversion to the Strata NSC valve, our patients had sustained clinical improvement, even at higher valve settings.

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Diagnosis and surgical strategy for sacral meningeal cysts with check-valve mechanism

sacral cysts

Acta Neurochir (2013) 155:309–313

There is agreement that symptomatic sacral meningeal cysts with a check-valve mechanism and/or large cysts representing space-occupying lesions should be treated surgically. This study investigated factors indicating a need for surgical intervention and surgical techniques for sacral meningeal cysts with a check-valve mechanism.

Methods In ten patients presenting with sciatica and neurological deficits, myelography, computed tomography (CT) myelography, and magnetic resonance imaging (MR imaging) detected sacral meningeal cysts with a check-valve mechanism. One patient had two primary cysts. Ten cysts were type 2 and one cyst was type 1. Nine of the ten patients had not undergone previous surgery, while the remaining case involved recurrent cyst. For the seven patients with normal (i.e., not huge or recurrent) type 2 cysts and no previous surgery (eight cysts), suture after collapse of the cyst wall was performed. For the recurrent type 2 cyst, duraplasty and suture with collapse of the cyst wall were performed to eliminate the check-valve mechanism. For the remaining type 2 cyst, a primary root was sacrificed because of the huge size of the cyst. For the type 1 cyst, the neck of the cyst was ligated.

Results In all cases, chief complaints disappeared immediately postoperatively and no deterioration of clinical symptoms has been seen after a mean follow-up of 27 months.

Conclusions The presence or absence of a check-valve mechanism is very important in determining the need for surgical intervention for sacral meningeal cysts.

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Cerebral arterial fenestrations: a common phenomenon in unexplained subarachnoid haemorrhage

Cerebral arterial fenestrations- a common phenomenon in unexplained subarachnoid haemorrhage

Acta Neurochir (2013) 155:217–222

Fenestrations of intracranial arteries are variants resulting from incomplete fusion of vessels during development with unknown clinical significance. They are best visualised with 3D rotational angiography (3DRA).

Objective In a prospective consecutive series of patients with suspected aneurysms, 3DRA was performed to identify not only the potential bleeding source but also to assess the frequency and location of any fenestrations of intracranial arteries.

Methods In 287 consecutive patients with possible intracranial aneurysms (accidental discovery or previous history of SAH), 3DRAs were prospectively performed, and the location of subarachnoid haemorrhage was assessed by CT.

Results Of 174 patients presenting with SAH, 153 had saccular aneurysms, and in 21 cases (12.1 %), no source of bleeding was found. In 20 of these 21 patients with “unexplained SAH” (95.2 %) an arterial fenestration was detected in the neighbourhood of the clot. The incidence of fenestration in the 153 aneurysmal SAH patients was 22.9 %, and it was 23.3 % in 266 patients with intracranial aneurysms (113 accidental and 153 ruptured).

Conclusions Arterial fenestration was detected in 22.9 % of ruptured cerebral aneurysms, in contrast with 95.2 % in patients with unexplained SAH, the difference being statisctically significant (p<0.01). Fenestration is a developmental defect, a structural wall weakness possibly making the vessel prone to rupture. Its incidence of nearly 100 % may suggest a connection with idiopathic SAH. The presented data indicate that arterial fenestrations are generally overlooked, and they can be considered as one of the candidates for the source of idiopathic SAH.

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Theories of CSF dynamics and hydrocephalus

Theories of cerebrospinal fluid dynamics and hydrocephalus

J Neurosurg Pediatrics 11:170–177, 2013

According to the CSF bulk flow theory, hydrocephalus is caused by an imbalance between CSF formation and absorption, or a block at various locations in the major CSF pathway. New theories, however, have been proposed in which minor CSF pathways may play a significant role in the development of congenital hydrocephalus.

The authors review major contributions to the literature and analyze the evolution of theories of CSF dynamics in relation to hydrocephalus, dividing their development into 4 stages on the basis of historical trends. In Stage I (prior to 1950), 2 systems of classifying hydrocephalus were proposed, namely Dandy’s classifications of communicating and noncommunicating hydrocephalus and Russell’s nonobstructive and obstructive hydrocephalus. In Stage II (1950–1974), based on these theories of major CSF pathway dynamics, treatment focused on ventriculostomy as an alternative to reduction of CSF production by choroid plexus coagulation. In Stage III (1975–1999), some of the specific forms of hydrocephalus, especially in premature infants, were found to be unsuitable for ventriculostomy. In Stage IV (2000–2008), selection of treatment modalities evolved further, with a focus on analysis of the chronological changes in CSF dynamics and the differences in absorption pathways in the developing and mature brains.

The authors focus on “minor pathway hydrocephalus” in the immature brain, differentiating it from the conventional classification of obstructive and nonobstructive “major pathway hydrocephalus.”

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Potential of MR spectroscopy for assessment of glioma grading

Glioma grading by MR spectroscopy

Clinical Neurology and Neurosurgery 115 (2013) 146– 153

Magnetic resonance spectroscopy (MRS) is an imaging diagnostic method based that allows non-invasive measurement of metabolites in tissues. There are a number of metabolites that can be identified by standard brain proton MRS but only a few of them has a clinical significance in diagnosis of gliomas including N-acetylaspartate, choline, creatine, myo-inositol, lactate, and lipids.

Methods: In this review, we describe potential of MRS for grading of gliomas.

Results: Low-grade gliomas are generally characterized by a relatively high concentration of Nacetylaspartate, low level of choline and absence of lactate and lipids. The increase in creatine concentration indicates low-grade gliomas with earlier progression and malignant transformation. Progression in grade of a glioma is reflected in the progressive decrease in the N-acetylaspartate and myo-inositol levels on the one hand and elevation in choline level up to grade III on the other. Malignant transformation of the glial tumors is also accompanied by the presence of lactate and lipids in MR spectra of grade III but mainly grade IV gliomas. It follows that MRS is a helpful method for detection of glioma regions with aggressive growth or upgrading due to favorable correlation of the choline and N-acetylaspartate levels with histopathological proliferation index Ki-67. Thus, magnetic resonance spectroscopy is also a suitable method for the targeting of brain biopsies.

Conclusions: Gliomas of each grade have some specific MRS features that can be used for improvement of the diagnostic value of conventional magnetic resonance imaging in non-invasive assessment of glioma grade.

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Axial Spondylectomy and Circumferential Reconstruction via a Posterior Approach

Axial spondylectomy

Neurosurgery 72:300–309, 2013

Spinal metastases of the second cervical vertebra are a subset of tumors that are particularly difficult to address surgically. Previously described techniques require highly morbid circumferential dissection posterior to the pharynx for resection and reconstruction.

OBJECTIVE: To perform a biomechanical analysis of instrumented reconstruction configurations used after axial spondylectomy and to demonstrate safe use of a novel construct in a patient case report.

METHODS: Several different published and novel reconstruction configurations were inserted into 7 occipitocervical spines that underwent axial spondylectomy. A biomechanical analysis of the stiffness of the constructs in flexion and extension, lateral bending, and rotation was performed. A patient then underwent a posterior-only approach for axial spondylectomy and circumferential reconstruction.

RESULTS: Biomechanical analysis of different constructs demonstrated that anterior column reconstruction with bilateral cages spanning the C1 lateral mass to the C3 facet in combination with occipitocervical instrumentation was superior in flexion-extension and equivalent in lateral bending and rotation to currently used constructs. The patient in whom this construct was placed via a posterior-only approach for axial spondylectomy and instrumentation remained at neurological baseline and demonstrated no recurrence of local disease or failure of instrumentation to date.

CONCLUSION: When C1 lateral mass to C3 facet bilateral cage plus occipitocervical instrumentation is compared with existing anterior and posterior constructs, this novel reconstruction is biomechanically equivalent if not superior in performance. In a patient, the posterior-only approach for C2 spondylectomy with the novel reconstruction was safe and durable and avoided the morbidity of the anterior approach.

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The enigma of bifocal germ cell tumors in the suprasellar and pineal regions: synchronous lesions or metastasis?

The enigma of bifocal germ cell tumors in the suprasellar

J Neurosurg Pediatrics 11:107–114, 2013

Intracranial germ cell tumors (GCTs) frequently present with bifocal lesions in both the suprasellar and pineal areas. The pathogenesis of these bifocal GCTs has been the subject of controversy. Bifocal GCTs may be caused by synchronous tumors or by metastatic spread of tumor cells from one site to the other. The prognosis associated with bifocal GCTs has also been a cause of concern.

Methods. The authors constructed a single-institution patient cohort comprising 181 patients with intracranial GCTs. The clinical characteristics of bifocal GCTs were compared with those of suprasellar and pineal GCTs.

Results. Bifocal GCTs were observed in 23 patients (12.8%). Eighteen patients presented with bifocal GCTs that were diagnosed as germinomas, but 5 patients exhibited mixed GCTs. Analyses of age distributions and comparisons of tumor sizes were compatible with a model of a metastatic origin of bifocal GCTs. Eleven patients (47.8%) presenting with bifocal GCTs exhibited tumor seeding at presentation. Tumor seeding was significantly associated with bifocal lesions (p < 0.001). Patients with bifocal germinomas showed significantly shorter event-free survival and overall survival than did those presenting with germinomas from a single site of origin.

Conclusions. Bifocal GCTs are not restricted to germinomas, as had been previously reported, but do include mixed GCTs. The authors hypothesize that bifocal GCTs may result from the metastatic spread of suprasellar or pineal GCTs. The bifocal presentation of germinomas may be a poor prognostic sign and should alert clinicians to the possibility of a disseminated disease.

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Endoscopic Transsphenoidal Surgery for Cushing Disease

Endoscopic for Cushing Disease

Neurosurgery 72:240–247, 2013

The efficacy of endoscopic transsphenoidal surgery (ETS) for Cushing disease has not been clearly established.

OBJECTIVE: To assess efficacy of a pure endoscopic approach for treatment of Cushing disease and determine predictors of remission.

METHODS: A prospectively acquired database of 61 patients undergoing ETS was reviewed. Remission was defined as postoperative morning serum cortisol of ,5 mg/dL or normal or decreased 24-hour urine-free cortisol level in follow-up.

RESULTS: Overall, hypercortisolemia resolved in 58 of 61 patients (95%) by discharge. Tumor size did not predict resolution of hypercortisolemia at discharge (microadenomas [97%], magnetic resonance imaging-negative Cushing [100%], macroadenomas [87%]). At 2- to 3-month evaluations, 45 of 49 patients (91.8%) were in remission. Fifty patients were followed for at least 12 months (mean, 28 months; range, 12-72). Forty-two (84%) achieved remission from a single ETS. In these patients, there was no significant difference in remission rates between microadenomas (93%), magnetic resonance imaging-negative (70%), and macroadenomas (77%). Patients with history of previous surgery (n = 14, 23%) were 9 times less likely to achieve follow-up remission (P = .021). In-house cortisol level of ,5.7 mg/dL provided the best prediction of follow-up remission (sensitivity 88.6%, specificity 83.3%). Postoperative diabetes insipidus occurred transiently in 7 patients (9%) and permanently in 3 (5%). One patient experienced postoperative cerebrospinal fluid leak that resolved with further surgery.

CONCLUSION: ETS for Cushing disease provides high rates of remission with low rates of complications regardless of size. Although patients with a history of previous surgery are less likely to achieve remission, the majority can still achieve remission following treatment.

KEYWORDS:

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Failed awake craniotomy: a retrospective analysis in 424 patients undergoing craniotomy for brain tumor

Awake cranio

J Neurosurg 118:243–249, 2013

Awake craniotomy for removal of intraaxial tumors within or adjacent to eloquent brain regions is a well-established procedure. However, awake craniotomy failures have not been well characterized. In the present study, the authors aimed to analyze and assess the incidence and causes for failed awake craniotomy.

Methods. The database of awake craniotomies performed at Tel Aviv Medical Center between 2003 and 2010 was reviewed. Awake craniotomy was considered a failure if conversion to general anesthesia was required, or if adequate mapping or monitoring could not have been achieved.

Results. Of 488 patients undergoing awake craniotomy, 424 were identified as having complete medical, operative, and anesthesiology records. The awake craniotomies performed in 27 (6.4%) of these 424 patients were considered failures. The main causes of failure were lack of intraoperative communication with the patient (n = 18 [4.2%]) and/or intraoperative seizures (n = 9 [2.1%]). Preoperative mixed dysphasia (p < 0.001) and treatment with phenytoin (p = 0.0019) were related to failure due to lack of communication. History of seizures (p = 0.03) and treatment with multiple antiepileptic drugs (p = 0.0012) were found to be related to failure due to intraoperative seizures. Compared with the successful awake craniotomy group, a significantly lower rate of gross-total resection was achieved (83% vs 54%, p = 0.008), there was a higher incidence of short-term speech deterioration postoperatively (6.1% vs 23.5%, p = 0.0017) as well as at 3 months postoperatively (2.3% vs 15.4%, p = 0.0002), and the hospitalization period was longer (4.9 ± 6.2 days vs 8.0 ± 10.1 days, p < 0.001). Significantly more major complications occurred in the failure group (4 [14.8%] of 27) than in the successful group (16 [4%] of 397) (p = 0.037).

Conclusions. Failures of awake craniotomy were associated with a lower incidence of gross-total resection and increased postoperative morbidity. The majority of awake craniotomy failures were preventable by adequate patient selection and avoiding side effects of drugs administered during surgery.

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C1–2 transarticular screws combined with C1 laminar hooks fixation

C1–2 transarticular screws combined with C1 laminar hooks fixation

Eur Spine J (2013) 22:260–267

Purpose To retrospectively evaluate the outcome of C1–2 transarticular screws combined with C1 laminar hooks fixation.

Methods All patients underwent atlantoaxial fixation during a 5-year period. The surgical technique and treatment procedures were intensively reviewed and clinical symptoms, neurological function and imaging appearance were retrospectively evaluated.

Results The clinical and radiology follow-up indicated a stable arthrodesis and clinical relief from symptoms for all patients. All patients with neurological defects improved an average of 1.33 grade at their most recent clinical assessment, P≤0.05; their average admission ASIA motor score, pin prick score and light touch score improved to an average follow-up ASIA score of 99.80 (99.83 ± 0.38), 111.83 (111.83 ± 0.45), and 111.89 (111.89 ± 0.32), respectively. No neurovascular impairment and case of implant failure were observed.

Conclusions The C1–2 transarticular screws combined with C1 laminar hooks fixation is a reliable technique for atlantoaxial instability.

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The Y-shaped double-barrel bypass in the treatment of large and giant anterior communicating artery aneurysms

Y-shaped bypass

J Neurosurg 118:444–450, 2013

Large and giant anterior communicating artery (ACoA) aneurysms usually show partial thrombosis and incorporate both the A1 and A2 segments and crucial perforating vessels. Therefore, direct clip placement or endovascular strategies often fail, leaving cerebral bypass surgery as a relevant therapeutic option.

The authors present 3 cases in which a giant or large ACoA aneurysm was successfully occluded using a new technique that applies a double-barrel radial artery bypass. A radial artery graft is modified into a Y-shaped double-barrel conduit. After both pterional and parasagittal craniotomies are carried out, the graft is tunneled between both sites and anastomosed in an end-to-side fashion proximally to either a superficial temporal artery (STA) or M2 branch and distally to bilateral A3 branches. Aneurysm occlusion is then conducted through the pterional or parasagittal craniotomy.

In one case, a 42-year-old patient in whom an endovascular approach had failed, the authors performed an STA-A3-A3 bypass and proximal aneurysm occlusion. In two others, a 49-year-old man in whom coiling had failed and a 56-year-old man in whom a giant ACoA aneurysm was partially thrombosed, the authors performed an M2-A3-A3 double-barrel bypass followed by either proximal or distal aneurysm occlusion. Complete aneurysm occlusion with excellent bypass perfusion was documented in the first two cases. In the third case, the authors observed good bypass perfusion with persistent antegrade aneurysm filling, and thus endovascular coil embolization was added to completely occlude the aneurysm.

The Y-shaped double-barrel bypass using a radial artery graft allows for safe and effective occlusion of large and giant ACoA aneurysms that cannot be treated by direct clip application.

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The diagnostic accuracy of brain microdialysis during surgery

Microdialysis

Acta Neurochir (2013) 155:345–353

Monitoring of brain function and metabolism during surgery may be of benefit for patient outcome. Microdialysis is the only sampling technique to date that allows continuous monitoring of drug or metabolite concentrations in the extracellular fluid of multiple tissues in the brain. This qualitative systematic review aimed to determine whether microdialysis is a valid tool for detecting changes in tissue composition as would be expected upon changes in (induced) tissue metabolic composition during brain surgery.

Methods A systematic review was conducted by performing a MEDLINE search using the terms “Intraoperative Period” (Medical Subject Heading [MeSH]) OR “Surgery” [Subheading] OR “Monitoring, Intraoperative” [MeSH] AND “Microdialysis” [MeSH] AND “Brain” [MeSH]. Two reviewers independently assessed the methodological quality of the studies. For each study the grades of recommendation were determined.

Results The search strategy yielded 46 publications in Medline. Data extraction was performed on 16 studies. The methodological quality of studies was low, with overall scores of 4 or 5. A quantitative analysis could not be performed because of lack of sufficient data. A qualitative analysis was positive with regard to the detection of different states of tissue composition by microdialysis. However, the levels of recommendation on the outcome statements were low, resulting in a grade D level of recommendation on all statements.

Conclusions The available evidence for the validity of cerebral microdialysis as a diagnostic tool during brain surgery is of low scientific quality. In order to develop cerebral microdialysis as a valid instrument for monitoring of brain metabolism during surgery, standardised clinical prospective studies in homogeneous patient populations are required.

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Basilar Tip Aneurysms: A Microsurgical and Endovascular Contemporary Series of 100 Patients

Basilar tip aneurysms

Neurosurgery 72:284–299, 2013

Endovascular therapy has largely replaced microsurgical clipping for the treatment of basilar tip aneurysms.

OBJECTIVE: We describe the variables our center evaluates when choosing to clip or coil basilar tip aneurysms and our outcomes. Four case illustrations are presented.

METHODS: All patients with ruptured or unruptured basilar tip aneurysms from 2005 to April 2012 were examined. The patients were treated by 2 interventional neuroradiologists and 2 dually trained neurosurgeons.

RESULTS: There were 63 ruptured (clipped 38%, coiled 62%) and 37 unruptured (clipped 35%, coiled 65%) aneurysms in this 100-patient study. Seventy percent of the patients with ruptured aneurysms and 92% of the patients with unruptured aneurysms had a good outcome (modified Rankin scale 0-2) at 3 months. For ruptured aneurysms, there was a statistically significant difference in clipping and coiling with respect to age and treatment modality (clip 48.8 years, coil 57.6 years). Patients in the coiled group had higher dome-to-neck (1.3 vs 1.1) (P = .01) and aspect ratios (1.6 vs 1.2) (P = .007). In the ruptured coiling group, 69.5% achieved a Raymond 1 radiographic outcome, 28% Raymond 2, and 2.5% Raymond 3. Eleven (17.4%) patients required re-treatment, and 3 (4.4%) patients were re-treated more than twice. Coiling of unruptured aneurysms resulted in 75% Raymond 1. There were no residual lesions for unruptured clipped aneurysms. There were no differences in outcome between clipping and coiling in the ruptured and unruptured group.

CONCLUSION: In our current management of basilar tip aneurysms, the majority can be treated via endovascular means, albeit with the expectation of a higher percentage of residual lesions and recurrences. Microsurgery is still appropriate for aneurysms with complex neck morphologies and in young patients desiring a more durable treatment.

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Incidence of growth and rupture of unruptured intracranial aneurysms followed by serial MRA

Incidence of growth and rupture of unruptured intracranial aneurysms followed by serial MRA

Acta Neurochir (2013) 155:211–216

The natural history, including growth and rupture, of unruptured intracranial aneurysms (UIAs) remains unknown. Here, we present the results of serial magnetic resonance angiography (MRA) follow-up study in 111 patients with 136 UIAs.

Method A total of 111 patients with 136 UIAs were followed annually over the past 12 years, using 1.5-Tesla MRA. Follow-up was ended when UIAs were treated surgically, or the patients died of subarachnoid hemorrhage or other causes. Various factors influencing aneurysm rupture or growth were examined statistically.

Results Aneurysm rupture and growth occurred in six and 13 of the 111 patients, respectively. Annual rupture rate was 1.8 % per year and annual growth rate was 3.9 % per year. Aneurysm size was the sole factor influencing rupture(H.R. 1.214, 95 % CI, 1.078–1.368) and multiplicity was the sole factor influencing aneurysm growth (H.R. 5.174, 95 % CI 1.81–14.80).

Conclusions Serial MRA study showed that the incidence of UIA growth was twice as high as that of UIA rupture. As four patients showed aneurysm rupture or growth within 1 year, further investigations are necessary to determine the optimum interval of radiological investigation and to identify which UIAs grow or rupture within a short time.

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Combined “Hybrid” Open and Minimally Invasive Surgical Correction of Adult Thoracolumbar Scoliosis: A Retrospective Cohort Study

00006123-201302000-00011

Neurosurgery 72:151–159, 2013

Surgery for scoliosis requires extensive exposure, resulting in significant tissue injury and longer recovery times. To minimize morbidity in scoliosis surgery, several studies have shown successful application of a combination of minimally invasive techniques; however, the extent of scoliosis treated has been modest.

OBJECTIVE: To achieve some of the benefits of minimally invasive surgery and yet treat curves of greater degree, we have used a combined approach, incorporating both open and minimally invasive techniques.

METHODS: We analyzed a prospectively acquired database in addition to reviewing electronic records of patients undergoing hybrid surgery for thoracolumbar scoliosis. Nine patients were identified. The minimally invasive portion involved the lumbar region in all cases. Pain was assessed by the visual analog scale and disability was measured by the Oswestry Disability Index.

RESULTS: Mean preoperative scoliosis was 47.8 degrees, which was corrected to a mean 15.2 degrees. An average of 7.8 spinal levels was treated. Estimated blood loss averaged 1094.4 mL, and length of hospital stay averaged 7.2 days. Acute complications occurred in 2 patients. Longer term complications occurred in 2 patients, consisting of adjacent segment disease. The mean improvement in the visual analog scale score was 3.7 and the mean improvement on the Oswestry Disability Index was 30.5. Average follow-up was 29.2 months.

CONCLUSION: The hybrid approach for the treatment of scoliosis results in acceptable radiographic and clinical outcomes. Complications did not appear increased compared with those expected with scoliosis surgery. Although decreased adjacent tissue injury was achieved with the minimally invasive component of the procedure, a larger comparative study is required to determine magnitude of this benefit.

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Technical nuances for surgery of insular gliomas: lessons learned

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Neurosurgical Focus Feb 2013 / Vol. 34 / No. 2 / Page E6

Insular gliomas were traditionally considered a nonsurgical entity due to the high morbidity associated with resection. For the past 20 years, advances in microsurgical and brain mapping techniques have allowed neurosurgeons to resect insular gliomas with acceptable morbidity rates. Maximizing the extent of resection is nowadays the goal of surgery since this has proven to be an independent factor contributing to longer survival. Despite much progress, insular tumors remain a challenge for the neurosurgeon due to the complex anatomy of the region and technical expertise required to minimize morbidity during surgery.

Herein, the authors describe the current surgical nuances, based on their experience and a literature review, that will allow the surgeon to achieve a thorough resection while ensuring patient safety. The key factors for successful surgery in the insular region include detailed knowledge of the surgical anatomy, mastery of the nuances of cortical and subcortical mapping methods, and meticulous microsurgical technique.

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Subcortical Injury Is an Independent Predictor of Worsening Neurological Deficits Following Awake Craniotomy Procedures

Subcortical_Injury_Is_an_Independent_Predictor_of

Neurosurgery 72:160–169, 2013

Tailored craniotomies for awake procedures limit cortical exposure. Recently we demonstrated that the identification of eloquent areas increased the risk of postoperative deficits. However, it was not clear whether the observed neurological deficits were caused by proximity of functional cortex to the tumor [cortical injury] or subcortical injury.

OBJECTIVE: We hypothesize that subcortical injury during tumor resection is an important predictor of postoperative neurological deficits compared to cortical injury.

METHODS: A retrospective review of 214 patients undergoing awake craniotomy was carried out in whom preoperative functional magnetic resonance imaging (fMRI) and cortical mapping (CM) were performed. A radiologist blinded to the clinical data reviewed and graded the postoperative changes on diffusion-weighted MR-imaging (DWI).

RESULTS: Of the 40 cases who developed new intraoperative neurological deficit, 36 (90%) occurred during subcortical dissection, 3 (7.5%) during both subcortical and cortical dissection, and 1 (2.5%) during cortical dissection. Neurological dysfunction acquired during subcortical dissection was an independent predictor of postoperative deficits both in the immediate postoperative period (P< .001) and at the 3-month follow-up (P < .001). Significant DWI restriction in the subcortical white matter was predictive of neurological deficits both immediately and at 3 months, P = .011 and P < .001, respectively. New or worsening deficits were seen in 38% of patients; however, at 3 months 13% had a mild persistent neurological deficit.

CONCLUSION: Subcortical injury with significant DWI changes result in postoperative neurological decline despite our efforts to preserve cortical areas of function. This underscores the importance of preserving subcortical fiber tracts during awake craniotomy procedures.

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