The Use of Diffusion Tensor Images of the Corticospinal Tract in Intrinsic Brain Tumor Surgery: A Comparison With Direct Subcortical Stimulation

Neurosurgery 71:331–340, 2012 DOI: 10.1227/NEU.0b013e31825b1c18

Diffusion tensor imaging (DTI) is now widely used in neurosurgery to preoperatively delineate the course of the pyramidal tract.

OBJECTIVE: To evaluate the accuracy of the method by comparison with subcortical electrical stimulation and to evaluate the influence of the distance of the pyramidal tract from the tumor on the resection extent and postoperative clinical deficits.

METHODS: A diffusion tensor imaging depiction of the pyramidal tract was used in preoperative planning and intraoperative navigation in 72 cases. In 36 cases, subcortical electrical stimulation was used during the resection. The preoperative tumor-to-tract distance was compared with the stimulation result, the extent of resection, and the short-term postoperative course.

RESULTS: A significant nonlinear relationship between the tract-to-tumor distance and the probability of a motor response to subcortical stimulation was observed. The largest preoperatively measured tumor-to-tract distance with a positive stimulation result was 8 mm. Moreover, we observed a trend toward transient postoperative motor deterioration in patients with tumors close to the pyramidal tract. Resection extent was not significantly affected by the tumor-to-tract distance.

CONCLUSION: Despite methodological obstacles, reasonable accuracy of the diffusion tensor imaging reconstructions of the pyramidal tracts was confirmed by our study. The occurrence of transient postoperative motor deterioration is higher in patients with tumors located close to the pyramidal tract.

Predictors of meningioma consistency: A study in 243 consecutive cases

Acta Neurochir (2012) 154:1383–1389 DOI 10.1007/s00701-012-1427-9

Meningioma is a common neoplasm primarily arising in the central nervous system. Its consistency is considered to be one of the critical prognostic factors for determining surgical resectability. The present study endeavored to investigate predictive factors associated with the tumor consistency.

Methods Two hundred and forty-three consecutive participants who underwent resective surgery of meningioma were examined. The authors designed an objective grading system for meningioma consistency and utilized it for assessing consistency among all cases. We focused on the relationship between preoperative tumor characteristics on neuroimaging studies and the consistency.

Results The tumor attributes on T2-weighted image (T2WI) and fluid attenuated inversion recovery (FLAIR) image were significantly correlated with the tumor consistency (p=0.004 and 0.045, respectively). The hypointense tumors on both MRI sequences tended to be hard, whereas the tumors showing hypersignal intensity were associated with soft consistency. There was no correlation between the consistency and age, gender, duration of neurologic symptoms, tumor location, size, calcification, cystic portion, en plague appearance, tumor-brain contact interface expressed by cerebrospinal fluid (CSF) cleft, perilesional vasogenic edema, bony status, features on T1-weighted image (T1WI) and pattern of contrast enhancement. In multiple logistic regression analysis, the tumor characteristics on T2WI and FLAIR image were independent factors significantly correlated with the tumor consistency (p=0.005 and 0.041, respectively). The tumor consistency was also correlated with operative radicalness as evaluated by the Simpson criteria.

Conclusions Signal intensity on T2WI and FLAIR image can be used for insinuating meningioma consistency. Presurgical prediction of the consistency is highly valuable in operative planning, particularly in arduous cases.

Strong 5-aminolevulinic acid-induced fluorescence is a novel intraoperative marker for representative tissue samples in stereotactic brain tumor biopsies

Neurosurg Rev (2012) 35:381–391 DOI 10.1007/s10143-012-0374-5

Stereotactic biopsies represent a routine neurosurgical procedure for the diagnosis of intracranial lymphomas and selected diffusely infiltrating gliomas. Acquisition of tissue samples that do not allow correct tumor typing and grading is, however, not uncommon. Five-aminolevulinic acid (5-ALA) has been shown to accumulate in malignant tumor tissue. The aim of this study was to prospectively investigate the clinical usability of 5-ALA for intraoperative detection of representative tissue in stereotactic tumor biopsies.

Fifty consecutive patients underwent frameless stereotactic biopsy for a suspected brain tumor. 5-ALA was administered 4 h before anesthesia. Serial biopsy samples were obtained and intraoperatively checked for 5-ALA fluorescence (strong, vague, or none) using a modified neurosurgical microscope. All samples were examined for the presence of representative tumor tissue according to neuroimaging (MRI, positron emission tomography, and/or chemical shift imaging) and histopathological parameters.

Visible 5-ALA fluorescence was observed in 43/50 patients (strong in 39 and vague fluorescence in four cases). At biopsy target, 52/53 samples of glioblastomas, 9/10 samples of gliomas grade III, and 14/16 samples of lymphomas revealed strong 5-ALA fluorescence. Samples with strong 5-ALA fluorescence were only observed at, but not outside the biopsy target. All tissue samples with strong 5-ALA fluorescence were representative according to our neuroimaging and histopathological criteria (positive predictive value of 100%). Our data indicate that strong 5-ALA fluorescence is a reliable and immediately available intraoperative marker of representative tumor tissue of malignant gliomas and intracranial lymphomas in stereotactic biopsies. Thereby, the application of 5- ALA in stereotactic brain tumor biopsies may in future reduce costs for operating room and neuropathology and may decrease procedure-related morbidity.

 

Subdural Hematoma in Patients With Cancer

Neurosurgery 71:74–79, 2012 DOI: 10.1227/NEU.0b013e3182517938

Subdural hematoma (SDH) in patients with cancer is poorly described, and its frequency and causes may have changed with recent oncologic advances.

OBJECTIVE: We conducted an analysis of the clinical and radiographic features, etiologies, treatments, and outcomes of patients with SDHs and cancer.

METHODS: We retrospectively identified patients at Memorial Sloan-Kettering Cancer Center with a diagnosis of SDH and cancer from January 2000 to December 2007. We analyzed clinical and radiographic data; multivariate Cox regression was performed to associate tumor type and etiology with survival outcome.

RESULTS: There were 90 patients; 66 had acute or subacute SDHs, 9 chronic SDHs, 11 subdural hygromas, and 4 SDHs of unclear chronicity. Gliomas (16%), leukemias (14%), and prostate cancers (14%) were the most frequent malignancies. The most common single etiologies were coagulopathy (27%) and trauma (11%). SDHs with multiple etiologies occurred in 25 patients (28%) with the combination of coagulopathy and trauma occurring in 15. Sixty patients (67%) were either completely or partially independent after SDH, and 1-year survival was 43% (95% confidence interval: 32.1-52.9). Overall survival correlated with etiology (P , .0001) and whether the malignancy was in remission (P = .005). Trauma was associated with the best overall survival compared with coagulopathy.

CONCLUSION: Leukemia and prostate cancer are the most common systemic cancers associated with SDH, and gliomas may predispose to SDH more often than previously recognized. Coagulopathy is common and associated with the worst outcome, but many patients experience good functional outcome and survival.

Surgical management of ventral and ventrolateral foramen magnum meningiomas

Neurosurg Rev (2012) 35:359–368

Foramen magnum meningioma poses a challenge for neurosurgeons. Prognosis has generally improved with diagnostic and surgical advances over the past two decades; however, it may ultimately depend more on the surgeon’s ability to tailor the approach and interpret intraoperative risks in single cases.

The series comprised 64 patients operated on for ventral and ventrolateral foramen magnum meningioma. All patients underwent preoperative magnetic resonance imaging and received surgery via the dorsolateral route, rendering the series homogeneous in neuroradiological workup and surgical treatment. Particular to this series was that the majority of patients were of advanced age (n=29; age, >65 years), had serious functional impairment (n=30, Karnofski score <70), and large tumors (mean diameter, 3.5 cm).

Total tumor removal was achieved in 52 (81 %) patients; operative mortality was nil. Early outcome varied depending on difficulties encountered at surgery (cranial nerve position and type of involvement in particular) and type of preoperative dysfunction. Long-tract signs and cerebellar deficits improved in 74 and 77 % of cases, respectively, but only 27 % of cranial nerve deficits did so. Surgical complications most often involved the cranial nerves: cranial nerve impairment, especially of the 9th through the 12th cranial nerves, due to stretching or encasement was noted in 44 cases. At final outcome assessment, two thirds of the cranial nerve deficits cleared, and all but two patients returned to a normal productive life. One patient was reoperated on during the follow-up period.

Foramen magnum meningiomas behave like clival or spinal tumors depending on their prevalent extension. A dorsolateral approach tailored to tumor position and extension and meticulous surgical technique allow for definitive control of surgical complications. Scrupulous postoperative care may prevent dysphagia, a major persistent complication of surgery. Long-term observation of indolent tumor behavior at follow-up suggests that incomplete resection may be a viable surgical treatment option.

Role of Cancer Stem Cells in Spine Tumors

Neurosurgery 71:117–125, 2012 DOI: 10.1227/NEU.0b013e3182532e71

The management of spinal column tumors continues to be a challenge for clinicians. The mechanisms of tumor recurrence after surgical intervention as well as resistance to radiation and chemotherapy continue to be elucidated. Furthermore, the pathophysiology of metastatic spread remains an area of active investigation.

There is a growing body of evidence pointing to the existence of a subset of tumor cells with high tumorigenic potential in many spine cancers that exhibit characteristics similar to those of stem cells. The ability to self-renew and differentiate into multiple lineages is the hallmark of stem cells, and tumor cells that exhibit these characteristics have been described as cancer stem cells (CSCs).

The mechanisms that allow nonmalignant stem cells to promote normal developmental programming by way of enhanced proliferation, promotion of angiogenesis, and increased motility may be used by CSCs to fuel carcinogenesis.

The purpose of this review is to discuss what is known about the role of CSCs in tumors of the osseous spine. First, this article reviews the fundamental concepts critical to understanding the role of CSCs with respect to chemoresistance, radioresistance, and metastatic disease. This discussion is followed by a review of what is known about the role of CSCs in the most common primary tumors of the osseous spine.

Significance of Simpson grading system in modern meningioma surgery

J Neurosurg 117:121–128, 2012. http://thejns.org/doi/abs/10.3171/2012.3.JNS111945

Techniques for the surgical treatment of meningioma have undergone many improvements since Simpson established the neurosurgical dogma for meningioma surgery in his seminal paper published in 1957. This study aims to assess the clinical significance and limitations of the Simpson grading system in relation to modern surgery for WHO Grade I benign meningiomas and to explore the potential of the cell proliferation index to complement the limitations in predicting their recurrence.

Methods. The surgical records of patients who underwent resection of intracranial meningiomas at the University of Tokyo Hospital between January 1995 and August 2010 were retrospectively analyzed. The authors investigated the relationships between recurrence-free survival (RFS) and Simpson grade or MIB-1 labeling index value.

Results. A total of 240 patients harboring 248 benign meningiomas were included in this study. Simpson Grade IV resection was associated with a significantly shorter RFS than Simpson Grade I, II, or III resection (p < 0.001), while no statistically significant difference was noted in RFS between Simpson Grades I, II, and III. Among meningiomas treated by Simpson Grade II and III resections, however, multivariate analysis revealed that an MIB-1 index of 3% or higher was associated with a significantly shorter time to recurrence.

Conclusions. The clinical significance of the different management strategies related to Simpson Grade I–III resection may have been diluted in the modern surgical era. The MIB-1 index can differentiate tumors with a high risk of recurrence, which could be beneficial for planning tailored optimal follow-up strategies. The results of this study appear to provide a significant backing for the recent shift in meningioma surgery from attempting aggressive resection to valuing the quality of the patient’s life.

Giant Invasive Spinal Schwannoma: Its Clinical Features and Surgical Management

Neurosurgery 71:58–67, 2012 DOI: 10.1227/NEU.0b013e31824f4f96

Giant invasive spinal schwannoma (GISS) is defined as a lesion that extends over . 2 vertebral levels, erodes vertebral bodies, and extends posteriorly and laterally into the myofascial planes. Because of its rarity, few reports have been issued.

OBJECTIVE: To analyze the clinical features and outcomes of GISS and to discuss surgical strategies.

METHODS: We analyzed the medical records, pathological findings, and radiographic studies of patients with GISS.

RESULTS: Fourteen patients with GISS were surgically treated between 2002 and 2007. Five lesions were in the sacral region, 4 in the lumbosacral, 2 in the thoracolumbar, and 1 each in the cervical, cervicothoracic, and thoracic regions. Gross total resection was performed in 11 of the 14 patients. Satisfactory decompression was performed in all patients for neural compression. Postoperatively, all patients showed relief of pre- operative pain and paresthesia. The growth potential with the Ki-67 index was . 2% in 6 patients, and 4 of them experienced tumor regrowth or recurrence. All patients were followed up for at least 24 months. Final follow-up magnetic resonance images showed asymptomatic small tumor recurrence on the sacrum in 2 patients. Two patients required spinal stabilization. No instability was found on follow-up.

CONCLUSION: Total resection is the treatment of choice for patients with GISS and provides functional improvements, low permanent morbidity, and a low rate of recurrence. Total resection of the intraspinal portion and regular follow-up with con- sideration of the Ki-67 index is recommended when total resection is not achieved.

 

A review of the role of stem cells in the development and treatment of glioma

Acta Neurochir (2012) 154:951–969. DOI 10.1007/s00701-012-1338-9

The neurosurgical management of patients with intrinsic glial cancers is one of the most rapidly evolving areas of practice. This has been fuelled by advances in surgical technique not only in cytoreduction but also in drug delivery. Further innovation will depend on a deeper understanding of the biology of the disease and an appreciation of the limitations of current knowledge.

Here we review the controversial topic of cancer stem cells applied to glioma to provide neurosurgeons with a working overview. It is now recognised that the adult human brain contains regionally specified cell populations capable of self-renewal that may contribute to tumour growth and maintenance following accumulated mutational change. Tumour cells adapted to maintain growth demonstrate some stem-like characteristics and as such constitute a legitimate therapeutic target. Cellular reprogramming technologies raise the potential of developing stem cells as novel surgical tools to target disease and possibly ameliorate some of the consequences of treatment. Achieving these goals remains a significant challenge to neurosurgical oncologists, not least in challenging how we think about treating brain cancer.

This review will briefly examine our understanding of adult stem cells within the brain, the evidence that they contribute to the development of brain tumours as tumour-initiating cells, and the potential implications for therapy. It will also look at the role stem cells may play in the future management of glioma.

Lateral Supraorbital Approach Applied to Tuberculum Sellae Meningiomas

Neurosurgery 70:1504–1519, 2012 DOI: 10.1227/NEU.0b013e31824a36e8

Various surgical approaches for the removal of tuberculum sellae meningiomas (TSMs) have previously been described.

OBJECTIVE: To assess the reliability and safety of the lateral supraorbital (LSO) approach to remove TSMs.

METHODS: We identified all TSM patients operated on at the Department of Neurosurgery at Helsinki University Central Hospital, Finland, by the senior author (J.H.) using the LSO approach between September 1997 and August 2010. We retrospectively analyzed the clinical data, radiological findings, surgical treatment, histology, and outcome of patients and discuss the operative technique.

RESULTS: Apparent complete tumor removal was achieved in 45 patients (87%). Of 42 patients, preexisting visual deficit improved in 22, remained the same in 13, and worsened in 7, and de novo visual deficit occurred in 1 patient. At 3 months postdischarge, 47 patients (90%) had a good recovery, 4 (8%) were moderately disabled, and 1 (2%) died 40 days after surgery of unexplained cardiac arrest. Seven patients (13%) had minimal residual tumors, 2 of which required reoperation. During the median follow-up of 59 months (range, 1-133 months), tumor recurred in 1 of the patients who had undergone a second operation.

CONCLUSION: TSMs of all sizes can be removed via the LSO approach with minimal morbidity and mortality. Low-power or no coagulation is recommended near the optic nerves and the optic chiasm to preserve their vascular support from the internal carotid artery perforators. Our results are comparable to those obtained using more extensive and time-consuming approaches. We recommend the LSO approach to remove TSMs.

Long-Term Surgical Outcomes of Spinal Meningiomas

Spine 2012 ; 37 : E617 – E623 

Although previous studies have demonstrated favorable surgical outcomes for spinal meningioma, with a low incidence of tumor recurrence, few have examined longterm surgical outcomes.

Methods. The influence of patient age, surgical margin status (Simpson grade), tumor location, and histological subtype on tumor recurrence were examined retrospectively. In addition, the resected dura mater from Simpson grade I cases was examined for invasive tumor cells and compared with the presence or absence of a dural tail sign on magnetic resonance image.

Results. Complete resection (Simpson grades I and II) was performed in 62 patients. Among them, the tumor recurrence rate was 9.7%, all in patients who underwent grade II resection for ventral spinal lesions. The mean duration to reoperation in these patients was 12.2 ± 5.2 years. Of the 6 patients who underwent incomplete resection (Simpson grade III/IV), all required reoperation for tumor recurrence or regrowth, 5 years later on average. Patients younger than 50 years at the initial surgery had a significantly higher recurrence rate than those aged 50 years or older. Histologic examination of 43 dura mater specimens from Simpson grade I-resection patients revealed tumor cell invasion between the inner and outer layers in 15 patients. This invasion was noted in 8 (29%) of 28 patients who were negative for the dural tail sign on magnetic resonance image, and in 7 (47%) of 15 patients who showed a positive dural tail sign. The MIB-1 index reached about 10% for dumbbell-type meningiomas invading the vertebral body; these were associated with repeated recurrence and unfavorable prognosis.

Conclusion. Long-term follow-up after surgery for meningiomas indicated that Simpson grade I resection should be selected whenever practicable when treating younger patients or dumbbelltype meningiomas. Tumors recurred at 12 years, on average, in approximately 30% of patients who underwent grade II resection.

Surgical results of an endoscopic endonasal approach for clival chordomas

Acta Neurochir (2012) 154:879–886. DOI 10.1007/s00701-012-1317-1

The surgical approaches for clival chordomas remain controversial, although the extent of resection is one of the most important factors for long survival rates. Recently an endoscopic endonasal approach in good collaboration with otolaryngologists has attracted major attention as a surgical approach for clival chordomas. We describe our experience with the endoscopic endonasal approach and provide a review of the literature.

Methods Between 2008 and 2011, six operations were performed via the endoscopic endonasal approach for clivus chordomas. The mean tumor size was 35 mm in diameter. The tumor location was mainly from the upper to middle clivus. The tumor extended into the cavernous sinus in five cases and intradurally in three cases. A binostril approach was performed in four cases, while a one nostril approach was performed in two cases.

Results Gross total removal was achieved in three cases. The analysis of cases with incomplete resection suggested that residual tumors were observed epidurally and subdurally. The residual on the epidura was observed from the posterior clinoid to the posterior compartment of the cavernous sinus. On the other hand, the residual on the subdural was observed behind the upper part of the pituitary gland. There was no postoperative cerebrospinal fluid (CSF) leakage using vascularized nasoseptal flaps in any of the cases.

Conclusions The endoscopic endonasal transclival approach allows an appropriate extent of resection with acceptable complication rates in comparison with other approaches. In our series, the accomplishment of gross total removal was associated with the relationship between the tumors and surrounding structures, such as the pituitary gland and the cavernous portion of the intracranial carotid artery (ICA).

Predictive Value and Safety of Intraoperative Neurophysiological Monitoring With Motor Evoked Potentials in Glioma Surgery

Neurosurgery 70:1060–1071, 2012 DOI: 10.1227/NEU.0b013e31823f5ade

Resection of gliomas in or adjacent to the motor system is widely performed with intraoperative neuromonitoring (IOM). Despite the fact that data on the safety of IOM are available, the significance and predictive value of the procedure are still under discussion. Moreover, cases of false-negative monitoring affect the surgeon’s confidence in IOM.

OBJECTIVE: To examine cases of false-negative IOM to reveal structural explanations.

METHODS: Between 2007 and 2010, we resected 115 consecutive supratentorial gliomas in or close to eloquent motor areas using direct cortical stimulation for monitoring of motor evoked potentials (MEPs). The monitoring data were reviewed and related to new postoperative motor deficit and postoperative imaging. Clinical outcomes were assessed during follow-up.

RESULTS: Monitoring of MEPs was successful in 112 cases (97.4%). Postoperatively, 30.3% of patients had a new motor deficit, which remained permanent in 12.5%. Progression- free follow-up was 9.7 months (range, 2 weeks-40.6 months). In 65.2% of all cases, MEPs were stable throughout the operation, but 8.9% showed a new temporary motor deficit, whereas 4.5% (5 patients) presented with permanently deteriorated motor function representing false-negative monitoring at first glance. However, these cases were caused by secondary hemorrhage, ischemia, or resection of the supplementary motor area.

CONCLUSION: Continuous MEP monitoring provides reliable monitoring of the motor system, influences the course of operation in some cases, and has to be regarded as the standard for IOM of the motor system. In our series, we found no false-negative MEP results.

Staged resection of large vestibular schwannomas

J Neurosurg 116:1126–1133, 2012.(http://thejns.org/doi/abs/10.3171/2012.1.JNS111402)

Staged resection of large vestibular schwannomas (VSs) has been proposed as a strategy to improve facial nerve outcomes and morbidity. The authors report their experience with 2-stage resections of large VSs and analyze the indications, facial nerve outcomes, surgical results, and complications. The authors compare these results with those of a similar cohort of patients who underwent a single-stage resection.

Methods. A retrospective review of all patients (age > 18 years) who underwent surgery from 2002 to 2010 for large (≥ 3 cm) VSs at the authors’ institution with a minimum of 6 months follow-up was undertaken. A first-stage retrosigmoid approach (without meatal drilling) was performed to remove the cerebellopontine angle portion of the tumor and to decompress the brainstem. A decision to stage the operation was made intraoperatively if there was cerebellar or brainstem edema, excessive tumor adherence to the facial nerve or brainstem, a poorly stimulating facial nerve, or a thinned or splayed facial nerve. A second-stage translabyrinthine approach was performed at a later date to remove the remaining tumor. The single-stage resection consisted of a retrosigmoid approach with meatal drilling. Patient charts were evaluated for tumor size, extent of resection, tumor recurrence, House-Brackmann facial nerve function grade, and complications.

Results. Twenty-eight and 19 patients underwent 2- or single-stage resection of a large VS, respectively. The average tumor size was 3.9 cm (range 3.2–7 cm) in the 2-stage group and 3.9 cm (range 3.1–5 cm) in the single-stage group. The mean follow-up was 36 ± 19 months in the 2-stage group versus 24 ± 14 months in the single-stage group. Gross-total or near-total resection was achieved in 27 (96.4%) of 28 patients in the 2-stage group and 15 (79%) of 19 patients in the single-stage group (p < 0.01). Anatomical facial nerve preservation was achieved in all but 1 patient (94.7%), and there were no recurrences on follow-up imaging in the 2-stage group. Good facial nerve functional outcome (House-Brackmann Grades I and II) at last follow-up was achieved in 23 (82%) of 28 patients in the 2-stage group and 10 (53%) of 19 patients in the single-stage group (p < 0.01). Cerebrospinal fluid leak–related complications (intracranial hypotension, blood patch, and lumboperitoneal shunt for pseudomeningocele) were more common in the 2-stage group. There were no postoperative strokes, hemorrhages, or deaths in either group.

Conclusions. The authors’ results suggest that staged resection of large VSs may potentially achieve better facial nerve outcomes. There does not appear to be added neurological morbidity with staged resections

Influence of Navigated Transcranial Magnetic Stimulation on Surgical Planning for Tumors in or Near the Motor Cortex

Neurosurgery 70:1248–1257, 2012 DOI: 10.1227/NEU.0b013e318243881e 

Brain tumor surgery near the motor cortex requires careful planning to achieve the optimal balance between completeness of tumor resection and preservation of motor function. Navigated transcranial magnetic stimulation (nTMS) can be used to map functionally essential motor areas preoperatively.

OBJECTIVE: To evaluate how much influence, benefit, and impact nTMS has on the surgical planning for tumors near the motor cortex.

METHODS: This study reviewed the records of 73 patients with brain tumors in or near the motor cortex, mapped preoperatively with nTMS. The surgical team prospectively classified how much influence the nTMS results had on the surgical planning. Stepwise regression analysis was used to explore which factors predict the amount of influence, benefit, and impact nTMS has on the surgical planning.

RESULTS: The influence of nTMS on the surgical planning was as follows: it confirmed the expected anatomy in 22% of patients, added knowledge that was not used in 23%, added awareness of high-risk areas in 27%, modified the approach in 16%, changed the planned extent of resection in 8%, and changed the surgical indication in 3%.

CONCLUSION: nTMS had an objective benefit on the surgical planning in one fourth of the patients and a subjective benefit in an additional half of the patients. It had an impact on the surgery itself in just more than half of the patients. By mapping the spatial relationship between the tumor and functional motor cortex, nTMS improves surgical planning for tumors in or near the motor cortex.

Surgery of Insular Nonenhancing Gliomas: Volumetric Analysis of Tumoral Resection, Clinical Outcome, and Survival in a Consecutive Series of 66 Cases

Neurosurgery 70:1081–1094, 2012.  DOI: 10.1227/NEU.0b013e31823f5be5

Despite intraoperative technical improvements, the insula remains a challenging area for surgery because of its critical relationships with vascular and neurophysiological functional structures.
OBJECTIVE: To retrospectively investigate the morbidity profile in insular nonenhancing gliomas, with special emphasis on volumetric analysis of tumoral resection.

METHODS: From 2000 to 2010, 66 patients underwent surgery. All surgical procedures were conducted under cortical-subcortical stimulation and neurophysiological monitor- ing. Volumetric scan analysis was applied on T2-weighted magnetic resonance images (MRIs) to establish preoperative and postoperative tumoral volume.

RESULTS: The median preoperative tumor volume was 108 cm3. The median extent of resection was 80%. The median follow-up was 4.3 years. An immediate postoperative worsening was detected in 33.4% of cases; a definitive worsening resulted in 6% of cases. Patients with extent of resection of . 90% had an estimated 5-year overall survival rate of 92%, whereas those with extent of resection between 70% and 90% had a 5-year overall survival rate of 82% (P , .001). The difference between preoperative tumoral volumes on T2-weighted MRI and on postcontrast T1-weighted MRI ([T2 2 T1] MRI volume) was computed to evaluate the role of the diffusive tumoral growing pattern on overall survival. Patients with preoperative volumetric difference , 30 cm3 demonstrated a 5-year overall survival rate of 92%, whereas those with a difference of . 30 cm3 had a 5-year overall survival rate of 57% (P = .02).

CONCLUSION: With intraoperative cortico-subcortical mapping and neurophysiologi- cal monitoring, a major resection is possible with an acceptable risk and a significant result in the follow-up.

Intradural spinal metastases: a surgical series of 15 patients

Acta Neurochir (2012) 154:871–877. DOI 10.1007/s00701-012-1313-5

Intradural spinal metastases are rare, and little is known regarding surgical indications and outcomes.

Methods A retrospective search identified adults with intradural spinal metastases operated on at the Mayo Clinic from 1994-2011. Data were collected regarding demographics, tumor type and location, and outcomes.

Results Fifteen patients with intradural spinal metastases were investigated. The age range was 38-74 years (mean= 55 years; ±SD=11.1). Predominant tumor location and type were lumbosacral and adenocarcinoma, respectively: 3 intramedullary and 12 extramedullary. Patients were operated on to relieve or prevent progressive/intractable neurological sequelae and/or pain. Of 13 who underwent resection, gross total removal was reported in 10; simple biopsy was performed in 2. There was one surgical complication, no medical complications, and no surgical mortality. At median follow-up of 1 month postoperatively, 10 of 15 patients were stable or improved. Of 13 patients who underwent resection, 10 were stable or improved. Of two patients who underwent biopsy, neither was stable or improved at follow-up. Using the Modified McCormick Scale, 11 of 15 patients were “functional” preoperatively and 4 went from “functional” preoperatively to “non-functional” postoperatively. Three of those four died within 60 days of surgery from systemic disease progression. Median hospital stay was 8 days. Ten of 15 patients died by the end of the study period, and the median survival of 15 patients was 5 months.

Conclusions With improved outcomes in metastatic cancer, more patients are encountered in practice. An aggressive surgical approach is warranted for extramedullary lesions, whereas caution is advised for intramedullary lesions. Postoperative functional decline is more likely due to systemic disease progression rather than surgery.

Jugular foramen paragangliomas: management, outcome and avoidance of complications in a series of 75 cases

Neurosurg Rev (2012) 35:185–194. DOI 10.1007/s10143-011-0346-1

Jugular foramen paragangliomas are rare skull base tumours posing multiple complex diagnostic and management problems. We did a study to evaluate surgical technique, outcome and complications in 75 cases of tumours treated by multidisciplinary approach (i.e. combined neurosurgery, neuroradiology, ear, nose and throat surgery and intensive care unit team).
Methods: Retrospective study on 75 consecutive patients with jugular foramen paragangliomas treated surgically from 1989 to 2005. Preoperative balloon occlusion test was performed in all patients as well as embolization (100%). A combined limited infratemporal and juxtacondylar approach was used in all patients.
Results: Gross total resection was achieved in 59 patients (78.7%). The most common complication was represented by lower cranial nerve deficits in five patients (6.6%), which was only temporary in three. Postoperative facial nerve weakness occurred in five cases (6.6%) and resolved in three of them. The remaining two patients underwent facial nerve reconstruction by hypoglossal/facial nerve anastomosis. Four patients (5.3%) had a postoperative cerebrospinal fluid leak, which was successfully treated by lumbar drainage. Two patients (2.7%) died because of complications related to surgical injury of lower cranial nerves: one patient developed aspiration pneumonia and septicemia and the second one developed a large cervicobulbar hematoma that led to severe respiratory distress and ultimately global cerebral hypoxia.
Conclusion: Paragangliomas are rare and complex skull base lesions that may be managed with low morbidity and mortality if a multidisciplinary approach is considered. Facial and lower cranial nerve postoperative deficits can be limited.

Awake surgery for incidental WHO grade II gliomas involving eloquent areas

Acta Neurochir (2012) 154:575–584.DOI 10.1007/s00701-011-1216-x
WHO grade II glioma (G2G) is a premalignant tumor, usually revealed by seizures in young patients living normal lives. G2G grows constantly and will inevitably become anaplastic. Surgical resection significantly increases the overall survival by delaying malignant transformation. Recently, a similar natural history was demonstrated in a patient with incidental G2G, with continuous growth and risk of anaplasia. Here, the aim was to study for the first time the functional results and extent of resection in a prospective series of patients who underwent resection for incidental G2G within eloquent areas.
Method G2G involving functional regions in the left dominant hemisphere was incidentally diagnosed in 11 asymptomatic patients. Resection was achieved in all cases after demonstration of a volumetric increase on serial MRIs. Intraoperative awake mapping was performed in the 11 patients.
Findings There were no cases of mortality or permanent postoperative deficit. A subtotal, total or even “supratotal” resection was achieved in the 11 cases, with no partial resections. All patients resumed normal social and professional lives, with no seizures (KPS 100). Due to slow tumor re-growth in three patients with subtotal resection, adjuvant chemotherapy was administrated in two cases and radiotherapy in one. With a mean follow-up of 40 months since surgery, there was no anaplastic transformation.
Conclusion These results show that surgery can be considered in incidental G2G, even in critical areas, with a minimal risk and optimal resection, thanks to intraoperative mapping. Such findings raise the question of an early detection.

Preoperative identification of the facial nerve in patients with large cerebellopontine angle tumors using high-density diffusion tensor imaging


 

J Neurosurg 116:697–702, 2012. http://thejns.org/doi/abs/10.3171/2011.12.JNS111404

Facial nerve paresis can be a devastating complication following resection of large (> 2.5 cm) cerebellopontine angle (CPA) tumors. The authors have developed and used a new high-density diffusion tensor imaging (HD-DT imaging) method, aimed at preoperatively identifying the location and course of the facial nerve in relation to large CPA tumors. Their study objective was to preoperatively identify the facial nerve in patients with large CPA tumors and compare their HD-DT imaging method with a traditional standard DT imaging method and correlate with intraoperative findings.

Methods. The authors prospectively studied 5 patients with large (> 2.5 cm) CPA tumors. All patients underwent preoperative traditional standard- and HD-DT imaging. Imaging results were correlated with intraoperative findings.

Results. Utilizing their HD-DT imaging method, the authors positively identified the location and course of the facial nerve in all patients. In contrast, using a standard DT imaging method, the authors were unable to identify the facial nerve in 4 of the 5 patients.

Conclusions. The HD-DT imaging method that the authors describe and use has proven to be a powerful, accurate, and rapid method for preoperatively identifying the facial nerve in relation to large CPA tumors. Routine integration of HD-DT imaging in preoperative planning for CPA tumor resection could lead to improved facial nerve preservation.