Outcomes and Complications of Gamma Knife Radiosurgery for Skull Base Meningiomas

Objective To review the outcomes and complications of meningiomas treated with gamma knife radiosurgery (GKRS) as a primary treatment as well as an adjunct therapy. Materials and Methods We performed a retrospective review (2000–2013) of 136 patients with meningiomas who received GKRS. Of 136 patients, 68 patients had recurrent or residual tumors after microsurgical resection, and the other 68 patients received GKRS alone. The study population was evaluated clinically and radiographically after GKRS treatment. Results GKRS in meningiomas showed significant variations in tumor growth control (decreased in 69 patients [50.7%], arrested growth in 47 patients [34.6%], and increased tumor size in 20 patients [14.7%]). Progression-free survival rates after GKRS at 3, 5, and 10 years were 98%, 95% and 85%, respectively. Overall improvement of signs and symptoms after GKRS was 30% (71% versus 41%) compared with pretreated sign and symptoms (p = 0.0001). The Karnofsky performance scale was significantly improved after GKRS compared with the pretreated status (92 versus 80). Twenty patients (14.7%) required resection after initial GKRS. Conclusion These study findings revealed that GKRS offers a high rate of tumor control, preservation of multiple nerve functions, and a good quality of life in both new and recurrent patients with meningiomas.     

Clinical and Radiologic Outcome of Gamma Knife Radiosurgery on Nonfunctioning Pituitary Adenomas

Objective To elucidate the role of Gamma Knife radiosurgery (GKRS) in the management of nonfunctioning pituitary adenomas (NFAs). Materials and Methods A retrospective review of 57 consecutive patients spanning 2000 to 2013 with NFAs was performed. Of 57 patients, 53 patients had recurrent or residual tumors after microsurgical resection. The study population was evaluated clinically and radiographically after GKRS treatment. The median follow-up time was 45.57 months. Results GKRS in pituitary adenomas showed significant variations in tumor growth control (decreased in 32 patients [56.1%], arrested growth in 21 patients [36.1%], and increased tumor size in 4 patients [7%]). Progression-free survival after GKRS at 3, 7, and 10 years was 100%, 98%, and 90%, respectively. The neurologic signs and symptoms were significantly improved after GKRS (14% versus 107%) compared with pretreated signs and symptoms (p < 0.0001). Five patients (8.8%) required additional treatment. Conclusion Recent follow-up revealed that GKRS offers a high rate of tumor control and preservation of neurologic functions in both new and recurrent patients with NFAs. Thus GKRS is an effective treatment option for recurrent and residual as well as newly diagnosed patients with NFAs.     

Preserving normal facial nerve function and improving hearing outcome in large vestibular schwannomas with a combined approach: planned subtotal resection followed by gamma knife radiosurgery

Objective

To perform planned subtotal resection followed by gamma knife surgery (GKRS) in a series of patients with large vestibular schwannoma (VS), aiming at an optimal functional outcome for facial and cochlear nerves.

Methods

Patient characteristics, surgical and dosimetric features, and outcome were collected prospectively at the time of treatment and during the follow-up.

Results

A consecutive series of 32 patients was treated between July 2010 and June 2016. Mean follow-up after surgery was 29 months (median 24, range 4–78). Mean presurgical tumor volume was 12.5 cm³ (range 1.47–34.9). Postoperative status showed normal facial nerve function (House–Brackmann I) in all patients. In a subgroup of 17 patients with serviceable hearing before surgery and in which cochlear nerve preservation was attempted at surgery, 16 (94.1%) retained serviceable hearing. Among them, 13 had normal hearing (Gardner–Robertson class 1) before surgery, and 10 (76.9%) retained normal hearing after surgery. Mean duration between surgery and GKRS was 6.3 months (range 3.8–13.9). Mean tumor volume at GKRS was 3.5 cm³ (range 0.5–12.8), corresponding to mean residual volume of 29.4% (range 6–46.7) of the preoperative volume. Mean marginal dose was 12 Gy (range 11–12). Mean follow-up after GKRS was 24 months (range 3–60). Following GKRS, there were no new neurological deficits, with facial and hearing functions remaining identical to those after surgery in all patients. Three patients presented with continuous growth after GKRS, were considered failures, and benefited from the same combined approach a second time.

Conclusion

Our data suggest that large VS management, with planned subtotal resection followed by GKRS, might yield an excellent clinical outcome, allowing the normal facial nerve and a high level of cochlear nerve functions to be retained. Our functional results with this approach in large VS are comparable with those obtained with GKRS alone in small- and medium-sized VS. Longer term follow-up is necessary to fully evaluate this approach, especially regarding tumor control.

     

Predictive Factors for Vision Recovery after Optic Nerve Decompression for Chronic Compressive Neuropathy: Systematic Review and Meta-Analysis

Objectives Surgical optic nerve decompression for chronic compressive neuropathy results in variable success of vision improvement. We sought to determine the effects of various factors using meta-analysis of available literature.Design Systematic review of MEDLINE databases for the period 1990 to 2010.Setting Academic research center.Participants Studies reporting patients with vision loss from chronic compressive neuropathy undergoing surgery.Main outcome measures Vision outcome reported by each study. Odds ratios (ORs) and 95% confidence intervals (CIs) for predictor variables were calculated. Overall odds ratios were then calculated for each factor, adjusting for inter study heterogeneity.Results Seventy-six studies were identified. Factors with a significant odds of improvement were: less severe vision loss (OR 2.31[95% CI = 1.76 to 3.04]), no disc atrophy (OR 2.60 [95% CI = 1.17 to 5.81]), smaller size (OR 1.82 [95% CI = 1.22 to 2.73]), primary tumor resection (not recurrent) (OR 3.08 [95% CI = 1.84 to 5.14]), no cavernous sinus extension (OR 1.88 [95% CI = 1.03 to 3.43]), soft consistency (OR 4.91 [95% CI = 2.27 to 10.63]), presence of arachnoid plane (OR 5.60 [95% CI = 2.08 to 15.07]), and more extensive resection (OR 0.61 [95% CI = 0.4 to 0.93]).Conclusions Ophthalmologic factors and factors directly related to the lesion are most important in determining vision outcome. The decision to perform optic nerve decompression for vision loss should be made based on careful examination of the patient and realistic discussion regarding the probability of improvement.     

Intraoperative Transcranial Motor-Evoked Potential Monitoring of the Facial Nerve during Cerebellopontine Angle Tumor Resection

Objective To determine whether transcranial motor-evoked potential (TCMEP) monitoring of the facial nerve (FN) during cerebellopontine angle (CPA) tumor resection can predict both immediate and long-term postoperative FN function.Design Retrospective review.Setting Tertiary referral center.Main Outcome Measures DeltaTCMEP (final-initial) and immediate and long-term facial nerve function using House Brackmann (HB) rating scale.Results Intraoperative TCMEP data and immediate and follow-up FN outcome are reported for 52 patients undergoing CPA tumor resection. Patients with unsatisfactory facial outcome (HB >2) at follow-up had an average deltaTCMEP of 57 V, whereas those with HB I or II had a mean deltaTCMEP of 0.04 V (t = -2.6, p < 0.05.) Intraoperative deltaTCMEP did not differ significantly between groups with satisfactory (HB I, II) and unsatisfactory (HB > 2) facial function in the immediate postoperative period.Conclusion Intraoperative TCMEP of the facial nerve can be a valuable adjunct to conventional facial nerve electromyography during resection of tumors at the CPA. Intraoperative deltaTCMEP >57 V may be worrisome for long-term recovery of satisfactory facial nerve function.     

Facial Nerve Schwannomas of the Cerebellopontine Angle: The Mayo Clinic Experience

Background There is often controversy regarding the optimal management for patients with facial nerve schwannomas (FNSs) of the cerebellopontine angle (CPA).Methods The clinical and radiological outcomes in 14 patients with CPA FNS were retrospectively reviewed.Results Patients underwent resection with anatomic nerve preservation (n = 3), facial-hypoglossal nerve anastomosis (n = 4), gamma knife radiosurgery (GKS) (n = 6), or observation (n = 1). A total of 83% of tumors that underwent GKS were stable or decreased in size. No patient who underwent resection showed evidence of tumor recurrence; the tumor under observation remained unchanged with normal facial function at the time of the last follow-up. Facial function was decreased in 57%, stable in 14%, and improved in 29% of those who underwent microsurgery. A total of 67% of patients who underwent GKS had stable facial function. Serviceable hearing was maintained in 50% of patients in the GKS group and 67% of the tumor resection group. Mean and median follow-up was 48 and 43 months, respectively (range, 12 to 95 months).Conclusion Observation should be the primary management when encountered with FNS of the CPA in those with good neurologic function. Microsurgery or radiosurgery may be used in those with poor facial function or tumor progression.     

Endoscopic Resection of Vestibular Schwannomas

Objective To report our results and the technical details of fully endoscopic resection of vestibular schwannomas. Design Prospective observational study. Setting A single academic institution involving neurosurgery and neurotology. Participants Twelve consecutive patients who underwent fully endoscopic resection of a vestibular schwannoma. Main Outcome Measures Hearing preservation, based on the American Association of Otolaryngology-Head and Neck Surgeons (AAO-HNS) score as well as the Gardener and Robertson Modified Hearing Classification (GR). Facial nerve preservation based on the House-Brackmann (HB) score. Results All patients successfully underwent gross total resection. Facial nerve preservation rate was 92% with 11 of 12 patients retaining an HB score of 1/6 postoperatively. Hearing preservation rate was 67% with 8 of 12 patients maintaining a stable AAO-HNS grade and GR score at follow-up. Mean tumor size was 1.5 cm (range: 1–2 cm). No patients experienced postoperative cerebrospinal fluid leak, infection, or cranial nerve palsy for a complication rate of 0%. Mean operative time was 261.6 minutes with an estimated blood loss of 56.3 mL and average length of hospital stay of 3.6 days. Conclusion A purely endoscopic approach is a safe and effective option for hearing preservation surgery for vestibular schwannomas in appropriately selected patients.     

How to distinguish tumor growth from transient expansion of vestibular schwannomas following Gamma Knife radiosurgery

Background

Typically, vestibular schwannomas (VS) react to Gamma Knife radiosurgery (GKRS) with a transient increase of tumor volume owed to tumor swelling at about 6 months followed by a reduction of tumor volume owed to tumor shrinkage at about 18 months. It is important to distinguish this transient tumor expansion (TTE) from tumor growth. We undertook this study to see if there is a typical time interval in the follow-up of VS following GKRS, which may indicate tumor growth rather than TTE.

Methods

We retrospectively reviewed the patient charts of patients who underwent GKRS for unilateral sporadic VS at the Gamma Knife Center Zurich from 1994–2009 and who were treated by J. Siegfried or one of the authors (TM). Tumor progression was defined as an increase of tumor volume of?≥?20 % as compared to the initial tumor volume at the earliest 2 years following GKRS. This time interval of?≥?2 years was chosen in order to distinguish TTE from genuine tumor progression. Whenever tumor enlargement was suspected on follow-up MRI at?≥?2 years following GKRS, tumor volumes were measured using custom software.

Results

From 1994–2009, 235 patients underwent GKRS in Zurich for unilateral sporadic VS. Tumor progression with a volume increase of?≥?20 % occurred in 21/235 (8.9 %) patients at 3.4 ± 0.9 years following GKRS. Seventeen out of 235 (7 %) patients had a clinically relevant tumor progression requiring microsurgery or repeat radiosurgery.

Conclusions

According to our data, time may be a good parameter distinguishing tumor progression due to tumor growth from TTE due to tumor swelling in VS following GKRS. Tumor growth seems to occur at about 3–4 years following GKRS for VS as opposed to TTE, which seems to be present at about 6–18 months following GKRS for VS.     

Proton Therapy for Skull Base Chordomas: An Outcome Study from the University of Florida Proton Therapy Institute

Objectives Skull base chordoma is a rare, locally aggressive tumor located adjacent to critical structures. Gross total resection is difficult to achieve, and proton therapy has the conformal advantage of delivering a high postoperative dose to the tumor bed. We present our experience using proton therapy to treat 33 patients with skull base chordomas. Design Retrospective outcomes study. Setting University of Florida Proton Therapy Institute; 2007 to 2011. Participants A total of 33 patients with skull base chordomas received postoperative three-dimensional conformal proton therapy. The patients were 79% male and 6% diabetic; 27% had received a gross total resection. Main Outcome Measures The gross tumor/tumor bed received a dose between 77.4 CGE and 79.4 CGE. Local control and overall survival were tracked, and radiation toxicity was assessed using a modified Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Scheme. Results Median follow-up for all patients was 21 months. Local control and overall survival rates at 2 years were 86% and 92%, respectively. Grade 2 toxicity was observed in 18% of our cohort in the form of unilateral hearing loss partially corrected with a hearing aid. No grade 2 or higher optic or brainstem toxicities were observed. Conclusions Proton therapy is an effective treatment modality for skull base chordomas.     

Grading of vestibular schwannomas and corresponding tumor volumes: ramifications for radiosurgery

Background

Patients with vestibular schwannomas (VS) are either assigned to watchful waiting, microsurgical resection, or radiosurgery. Decision making on how to proceed is based on parameters such as age, tumor growth, loss of hearing, and the tumor’s Koos grading.

Methods

In order to correlate Koos grading with tumor volume, patient records of 235 patients with VS who underwent Gamma Knife radiosurgery (GKRS) were retrospectively reviewed.

Results

From 1994 to 2009, 235 consecutive patients underwent GKRS for sporadic VS at the Zurich Gamma Knife Center. Median follow up was 62.8 ± 33.0 months. Of the 235 tumors, 32 (13.6 %) were graded Koos I with a volume of 0.25 ± 0.3 cc; 71 (30.2 %) were graded Koos II with a volume of 0.57 ± 0.54 cc; 70 (29.8 %) were graded Koos III with a volume of 1.82 ± 1.88 cc; and 62 (26.4 %) were graded Koos IV with a volume of 4.17 ± 2.75 cc. Tumor progression was defined as a volume increase > 20 % at 2 years or later following GKRS. Overall tumor progression occurred in 21/235 (8.9 %) patients at 3.4 ± 0.9 years. Tumor progression did not differ statistically significantly in the various Koos grades: 1/32 (3.1 %) patients with VS Koos Grade I, 7/71 (9.8 %) patients with VS Koos Grade II, 6/70 (8.6 %) patients with VS Koos Grade III, and 7/62 (11.3 %) patients with VS Koos Grade IV.

Conclusion

To our knowledge, this is the first work correlating the various Koos grades of VS to their respective tumor volumes. In our patients, tumor volumes of VS Koos Grade IV were limited because all of our patients were eligible for radiosurgery. In our series, the outcome following GKRS for patients with VS Koos Grade IV tumors did not differ from patients with VS Koos Grades I–III. We therefore suggest to limit Koos Grade IV VS to tumor volumes < 6 cc that may be eligible for radiosurgery, and introduce an additional VS Grade V for large VS with tumor volumes of > 6 cc that may not be eligible for radiosurgery.     

Magnetic Resonance Imaging Criteria to Predict Complete Excision of Parasellar Pituitary Macroadenoma on Postoperative Imaging

Purpose To evaluate preoperative magnetic resonance imaging (MRI) criteria for their ability to predict the complete removal of parasellar pituitary macroadenoma on the 3-month postoperative MRI. Methods Dedicated pre- and postoperative pituitary MRI studies were reviewed in 49 patients who had undergone transsphenoidal surgery for macroadenomas with potential unilateral parasellar involvement. Twelve preoperative MRI findings and postoperative MRI outcomes were statistically compared. Results Depiction of the inferolateral (positive predictive value [PPV]: 0.6; negative predictive value [NPV], 0.92) and lateral (PPV: 0.65; NPV: 0.85) compartments of the cavernous sinus and the percentage of intracavernous carotid artery encasement (PPV: 0.63; NPV, 1.0 for <50% encasement) were the only criteria significantly predictive of parasellar tumor complete resection. The odds ratios indicated that depiction of the lateral venous or inferolateral venous compartments increased the likelihood of a complete resection by 6 times, whereas for every 25% reduction in intracavernous carotid artery encasement, the chance of a complete resection increased 3.4 times. Conclusion The preoperative MR imaging features that are useful in predicting the complete removal of the parasellar component of a pituitary adenoma as assessed by postoperative MRI are (1) depiction of the lateral and inferolateral compartment of the cavernous sinus and (2) decreasing encasement of the intracavernous carotid artery.     

Imaging of Resected Nonfunctioning Pituitary Adenomas: The Cost of Surveillance

Objectives To determine the cost of annual magnetic resonance imaging (MRI) surveillance after resection of nonfunctioning pituitary adenomas (NFPAs) and its effectiveness in reducing visual compromise due to tumor recurrence. Design Retrospective case series. Setting Vanderbilt University Medical Center (2003–2011). Participants A total of 120 patients underwent primary transsphenoidal resection and surveillance of NFPAs between 2003 and 2011. Main Outcome Measures Time from initial surgery to most recent imaging or progression. Surveillance MRI costs according to Centers for Medicare and Medicaid database and visual field deficits. Results Patients received 382 surveillance scans at a total cost of $218,477.30. The median follow-up was 47 months (interquartile range [IQR]: 26–76), and the median interval between scans was 357 days (IQR: 225–434). Overall, 50 scans (13%) revealed tumor growth. The cost per scan revealing growth was $4,369.55. The cost to identify 19 patients (16%) with clinically significant growth was $11,498.80 per patient. A total of 5 of 19 patients (26%) experienced new visual deficits prior to intervention. Patients with visual decline tended to have longer scan intervals than those with preserved vision (mean: 239 versus 794 days; p = 0.0584). No patient with annual surveillance imaging experienced visual decline. Conclusions Annual MRI scans are a sensitive and cost-conscious method to identify NFPA recurrence prior to visual decline.     

Lateral Temporal Bone Resection in Advanced Cutaneous Squamous Cell Carcinoma: Report of 35 Patients

Objective To evaluate lateral temporal bone resection (LTBR) in the management of advanced cutaneous squamous cell carcinoma (SCC) with temporal bone invasion and patterns of failure.Methods This is a retrospective study of 35 patients undergoing lateral temporal bone resection for advanced cutaneous SCC at a tertiary care center between 1995 and 2006.Results The Pittsburgh tumor stage was T4 in 18 patients (51%), T3 in 5 (14%), T2 in 9 (26%), and T1 in 3 (9%). Clear margins were reported in 22 (63%) patients. Resection of the mandible and/or temporomandibular joint (TMJ) was required in 11 (31%) patients. Facial nerve involvement was seen in 10 (29%) patients. Survival outcomes at 2 and 5 years for overall survival were 72% and 49%; disease-free survival, 68% and 59%; and disease-specific survival, 79% and 62%, respectively. Pittsburgh T stage correlated significantly with disease-specific survival (p = 0.015) and margin status was significant for both disease-free survival (p = 0.0015) and disease-specific survival (p < 0.001).Conclusions Surgery with curative intent is justified for cutaneous SCC invading the temporal bone with extended LTBR. Margin status was a significant predictor of outcome. Surgeons should plan preoperatively to achieve clear margins by extending the LTBR with possible nerve resection.     

Gamma knife radiosurgery for benign cavernous sinus tumors: quantitative analysis of treatment outcomes

OBJECTIVE: We review our 8-year experience with gamma knife radiosurgery (GKRS) for the treatment of patients with benign cavernous sinus tumors and present a quantitative analysis of factors relevant to treatment outcomes. METHODS: From 1994 to 2002, a total of 139 patients with benign cavernous sinus tumors were treated in 145 sessions. Their median age was 53 years, and the median follow-up was 3.5 years. The tumors included 57 meningiomas, 76 pituitary tumors (49 nonfunctional adenomas, 15 prolactinomas, 5 adrenocorticotropic hormone-secreting tumors, 6 growth hormone-secreting tumors, and 1 plurihormone-secreting tumor), 4 schwannomas, 1 hemangioma, and 1 paraganglioma. Sekhar tumor grades were as follows: I, n = 28 (20%); II, n = 42 (30%); III, n = 42 (30%); IV, n = 19 (14%); and V, n = 8 (6%). The median tumor volume was 3.4 cm(3), and the median prescribed dose was 15 Gy defined to the 50% isodose line. RESULTS: A total of 136 treated tumors (97.8%) were well controlled by GKRS, with low morbidity. For meningiomas, 29 tumors (51%) were unchanged and 26 (46%) were smaller at a median of 15.2 months. For pituitary tumors, 50 (66%) were unchanged and 25 (33%) were smaller at a median of 20.6 months. Improvement in cranial nerve (CN) function was seen in 19 (36.5%) of 52 patients with pre-GKRS deficits, and 3 patients (2.2%) developed new stable CN deficits after GKRS: 1 patient developed IVth CN palsy at 9 months, and 2 developed persistent VIth CN palsies at 43 and 45 months, respectively, that required surgical correction. Two patients developed transient VIth CN palsies at 48 months that self-resolved after another year. Endocrine function normalized for all 6 treated patients with a growth hormone-secreting tumor at a median of 18 months. One of the 5 adrenocorticotropic hormone-secreting tumors required retreatment after 17 months because of continued cortisol elevation. Thirteen (87%) of 15 prolactinoma patients had normalized prolactin levels within 2 years of the procedure; 2 patients relapsed by endocrine criteria at 18 and 22 months after GKRS. Two patients with normalized prolactin levels completed three normal pregnancies within 3 years of treatment. Six patients (4.3%) with a median tumor volume of 8 cm(3) developed radiation-induced injury at a median of 36 months after GKRS. Five of these patients also underwent external beam radiotherapy and received a median dose of 52.2 Gy in 30 fractions. Quantitative analysis revealed that the radiation dose to critical structures (optic apparatus and pons) is correlated with their distance from tumor margins. Underdosed tumor volume, tumor volume, and total treated volume are correlated with treatment outcomes. CONCLUSION: GKRS is a safe and effective treatment for selected patients with benign cavernous sinus tumors and is an important adjunct for treating postoperative tumor residual and/or recurrent tumor. Continued analysis of treated patients over an extended time is needed to evaluate long-term disease control and potential late GKRS complications.     

Clinical Outcomes of Surgical Management of Primary Brachial Plexus Tumors

Introduction  This study evaluates the clinical presentation, tumor characteristics, and clinical outcomes of surgically treated benign and malignant brachial plexus tumors (BPTs). Methods  A prospective study of patients with BPTs from June 2015 to August 2020 was conducted. All patients underwent surgical resection with microneurolysis and intraoperative electrical stimulation to preserve the functioning nerve fascicles. Results  Fourteen patients with 15 BPTs underwent surgical resection. Mean age was 37.8 ± 12.3 years; with male to female ratio 4:10. The clinical presentations were swelling (100%), pain (84.6%), and paresthesia (76.9%). The lesions involved roots (5/15), trunk (5/15), division (1/15), and cords (4/15). Thirteen patients had benign pathology (8 schwannomas, 3 neurofibromas, 2 lipomas) and two had malignant neurofibrosarcoma. Gross total resection was achieved in all cases except a dumbbell tumor. The mean follow-up period was 24 ± 5 months. Postoperatively, all patients reported improvement in pain and paresthesia with no new sensory deficit. All patients had developed initial motor weakness (Grades 2–4); however, full power (Grade 5) was recovered by 3 to 5 months. Conclusion  Total resection can be achieved by appropriate microneural dissection and electrophysiologic monitoring and is potentially curative with preserving function.     

Communicating Hydrocephalus and Vestibular Schwannomas: Etiology,Treatment, and Long-Term Follow-Up

Background Large vestibular schwannomas (VSs) can cause hydrocephalus by obstructing the fourth ventricle. Little is known about the communicating hydrocephalus that is seen with a smaller VS.Methods The clinicopathological findings and follow up of three patients with communicating hydrocephalus associated with a small VS are presented.Results Four patients aged 40 to 66 years (mean: 57.7) presented with ataxia, dementia, and urinary incontinence. The VS were 2.0 to 2.4 cm. The cerebrospinal fluid (CSF) protein was elevated in three patients in whom it was measured (1.7 to 6 times normal). The VS was resected in two patients. All of the patients required ventriculoperitoneal shunting (VPS). All of the patients were asymptomatic or improved at follow-up at 9 months to 13 years.Conclusion Communicating hydrocephalus associated with a VS can occur in younger patients than was previously thought. An elevated CSF protein appears to be important, but other factors may be involved. A shunting procedure is often required to relieve the symptoms of hydrocephalus even if the tumor is resected. Possible etiological causes of communicating hydrocephalus in patients with a small VS are discussed.     

Facial Nerve Function after the Extended Translabyrinthine Approach

Objective To evaluate facial nerve function after excision of petroclival/anterior cerebellopontine angle (CPA) meningiomas by the extended translabyrinthine (EXTL) approach and compare these with outcomes after the transcochlear and transotic approaches. Design Retrospective chart review. Setting/Participants A search of archived surgical cases at a single institution between January 1, 1995, and January 1, 2012. Main Outcome Measures Facial function measured on the House-Brackmann (HB) scale. Results A total of 16 patients underwent the EXTL approach for primary excision of petroclival meningiomas. Average tumor size was 4.6 cm, and six patients had gross total resection. Average length of follow-up was 36.4 months. Two patients required reoperation for tumor regrowth. Preoperative facial function was HB I or II in all patients with available examinations. Immediate postoperative facial nerve function ranged from HB I to HB VI. In patients with an intact facial nerve at surgery, all but one had long-term facial function of HB I or II. A robust response on intraoperative facial nerve monitoring was prognostic of favorable long-term facial function. Facial function declined in some patients after postoperative radiation or revision surgery. Conclusions The EXTL approach allows excellent exposure of petroclival/anterior CPA lesions and should be favored to improve facial outcomes.     

Indicators of a Reduced Intercarotid Artery Distance in Patients Undergoing Endoscopic Transsphenoidal Surgery

Objective To identify clinicopathologic factors associated with a reduced intercarotid distance (ICD) and subgroups at risk for internal carotid artery injury during transsphenoidal surgery. Design A retrospective case-control study. Setting This study was conducted at the McGill University Health Centre, a university-affiliated tertiary care center. Participants Patients with a sellar or parasellar tumor and nontumor controls were included in the study. Main Outcome Measures The smallest distance between the internal carotid arteries at the clival, cavernous, and paraclinoid segments on coronal magnetic resonance imaging was measured. Demographic profiles, cephalometric measurements, tumor dimensions, and sphenoid configuration were assessed as potential determinants of the ICD. Results A total of 212 cases and 34 controls were analyzed. Widening of the ICD at the three segments of the internal carotid arteries was found in patients with pituitary macroadenomas (p < 0.01). Patients with a growth hormone–secreting adenoma had a markedly reduced ICD at the clivus compared with controls (1.59 cm versus 1.77 cm; p = 0.02; 95% confidence interval [CI], 0.03–0.32). The paraclinoid ICD was reduced in patients with an anterior fossa meningioma (1.24 cm versus 1.33 cm; p = 0.04; 95% CI, 0.01–0.45). Conclusion Identifying clinicopathologic factors affecting the ICD can help surgeons recognize constraints to endoscopic access of the skull base and avoid inadvertent arterial injury.     

Craniofacial Surgery for Esthesioneuroblastoma: Report of an International Collaborative Study

Introduction Impact of treatment and prognostic indicators of outcome are relatively ill-defined in esthesioneuroblastomas (ENB) because of the rarity of these tumors. This study was undertaken to assess the impact of craniofacial resection (CFR) on outcome of ENB.Patients and Methods Data on 151 patients who underwent CFR for ENB were collected from 17 institutions that participated in an international collaborative study. Patient, tumor, treatment, and outcome data were collected by questionnaires and variables were analyzed for prognostic impact on overall, disease-specific and recurrence-free survival. The majority of tumors were staged Kadish stage C (116 or 77%). Overall, 90 patients (60%) had received treatment before CFR, radiation therapy in 51 (34%), and chemotherapy in 23 (15%). The margins of surgical resection were reported positive in 23 (15%) patients. Adjuvant postoperative radiation therapy was used in 51 (34%) and chemotherapy in 9 (6%) patients.Results Treatment-related complications were reported in 49 (32%) patients. With a median follow-up of 56 months, the 5-year overall, disease-specific, and recurrence-free survival rates were 78, 83, and 64%, respectively. Intracranial extension of the disease and positive surgical margins were independent predictors of worse overall, disease-specific, and recurrence-free survival on multivariate analysis.Conclusion This collaborative study of patients treated at various institutions across the world demonstrates the efficacy of CFR for ENB. Intracranial extension of disease and complete surgical excision were independent prognostic predictors of outcome.     

Management of Hypoglossal Schwannomas: Single Institutional Experience of 14 Cases

Background Hypoglossal schwannomas are rare intracranial neoplasms. Microsurgical resection with the goal of cure is the aim of management but is associated with a high rate of postoperative morbidity. Objective The objective of the study was to outline the clinical presentation, radiologic characteristics, surgical techniques, postoperative morbidity, and long-term follow-up results for hypoglossal schwannomas. Methods Patients treated for hypoglossal schwannoma at the Department of Neurosurgery of a tertiary-level referral institution from January 2001 until December 2010 were analyzed retrospectively using hospital records. Results There were 14 patients who were treated in the study period. Tongue atrophy and swallowing difficulties were the most common presenting symptoms. Surgery done in 12 patients using a variety of approaches (retromastoid retrosigmoid suboccipital in 9, midline suboccipital in 2, and far lateral in 1). Five patients having small residual tumors received gamma knife (GK) subsequently. two patients received primary GK stereotactic radiosurgery. Three patients had permanent morbidity in the form of cranial nerve paresis. Immediate postoperative complications like cerebrospinal fluid leak and pneumonia were present in three patients. Conclusion Complete microsurgical resection is often associated with a high rate of morbidity. Subtotal and near-total resection followed by stereotactic radiosurgery or observation now offers an alternative approach.