A case series of atypical features of patients with biopsy-proven isolated IgG4-related hypophysitis and normal serum IgG4 levels.

BACKGROUND: IgG4-related hypophysitis is a rare clinical entity that forms part of an emerging group of multi-organ IgG4-related fibrosclerotic systemic diseases. The rare prevalence of the disease, presenting features that overlap with other sellar pathologies, and variable imaging features can make preoperative identification challenging. PURPOSE AND METHODS: We report three cases of isolated IgG4-related hypophysitis with atypical clinical and imaging features that mimicked those of pituitary apoplexy and other sellar lesions. Additionally, we review the literature of IgG4-related hypophysitis to provide context for individual patient data described herein. RESULTS: All patients presented with symptoms that mimicked those of pituitary apoplexy and visual disturbance, and MRI findings suggestive of pituitary macroadenoma, Rathke's cleft cyst and craniopharyngioma. The clinical presentation warranted surgical decompression, resulting in rapid symptomatic improvement. Preoperative high-dose followed by postoperative low-dose glucocorticoid replacement therapy was administered in all cases. Histopathology showed dense infiltrate of IgG4 cells. Post-operative follow-up monitoring for 12-26 months revealed normal serum IgG4 levels with no other organ involvement, while endocrinological testing revealed persistent pituitary hormone deficiencies. CONCLUSIONS: Our cases highlight the importance of considering IgG4-related hypophysitis in the differential diagnosis of solid and cystic sellar lesions presenting acutely with pituitary apoplexy symptoms. Existing diagnostic criteria may not be sufficiently precise to permit rapid and reliable identification, or avoidance of surgery in the acute setting. In contrast to other reports of the natural history of this condition, despite the severity of presenting features, the disease in our cases was pituitary-restricted with normal serum IgG4 levels.

Growth hormone granulation pattern and somatostatin receptor subtype 2A correlate with postoperative somatostatin receptor ligand response in acromegaly: a large single center experience.

Acromegaly is associated with serious morbidity and mortality, if not well controlled. Approved somatostatin receptor ligands (SRLs) are a mainstay of medical therapy and exhibit preferential affinity for somatostatin receptor (SSTR) subtype 2. Our objective was to assess whether characteristic features of individual growth hormone (GH)-secreting adenomas at diagnosis, correlated with SRL sensitivity, using defined tumor markers. A retrospective review of 86 consecutive acromegaly surgeries (70 patients) performed between January 2006 and December 2011 was undertaken. Patients with any preoperative medical treatment were excluded. Response to SRL therapy was defined as normalization of insulin-like growth factor 1 (IGF1) and random GH < 1.0 ng/dl. Immunohistochemical staining pattern: sparsely granulated, densely granulated, mixed growth hormone-prolactin (GH/PRL) and SSRT2 positivity (+) were correlated with clinicopathologic features, adenoma recurrence, and SRL treatment response. Two-tailed t test, univariate ANOVA, Kruskal-Wallis and bivariate correlation were performed using PAWS 18. The cohort eligible for analysis comprised 59 patients (41 female and 18 male). Based on pre-surgery adenoma imaging dimensions, 81.3% (48) were macroadenomas and average maximum tumor diameter was 18.1 ± 9.9 mm. Patients on SRLs were followed for 13.4 ± 15.8 (mean ± SD) months. Sparsely granulated adenomas were significantly larger at diagnosis, exhibited lower SSTR2 positivity and had a lower rate of biochemical normalization to SRLs. Densely granulated adenomas were highly responsive to SRLs. Overall, patients with SSTR2A+ adenomas responded more favorably to SRL treatment than those with SSTR2A- adenomas. Eighty-one percent of patients with SSTR2A+ adenomas were biochemically controlled (both GH and IGF1) on SRL treatment, e.g. a much higher normalization rate than that reported in the unselected acromegaly population (20-30%). Detailed knowledge of adenoma GH granularity and the immunohistochemical SSTR2A+ status is a predictor of SRL response. These immunoreactive markers should be assessed routinely on surgical specimens to assess subsequent SRL responsiveness and potential need for adjunctive therapy after surgery.

Remission rate after transsphenoidal surgery in patients with pathologically confirmed Cushing's disease, the role of cortisol, ACTH assessment and immediate reoperation: a large single center experience.

Postoperative serum cortisol is used as an indicator of Cushing's disease (CD) remission following transsphenoidal surgery (TSS) and guides (controversially) the need for immediate adjuvant treatment for CD. We investigated postoperative cortisol and adrenocorticotropic hormone (ACTH) levels as predictors of remission/recurrence in CD in a large retrospective cohort of patients with pathologically confirmed CD, over 6 years at a single institution. Midnight and morning cortisol, and ACTH at 24-48 h postoperatively (>24 h after last hydrocortisone dose) were measured. Remission was defined as normal 24-h urine free cortisol, normal midnight salivary cortisol, a normal dexamethasone-corticotropin releasing hormone (CRH) test or continued need for hydrocortisone, assessed periodically. Statistical analysis was performed using PASW 18. Follow up data was available for 52 patients (38 females and 14 males), median follow up was 16.5 month (range 2-143 months), median age was 45 years (range 21-72 years), 28 tumors were microadenomas and 16 were macroadenomas, and in eight cases no tumor was observed on magnetic resonance imaging. No patient with postoperative cortisol levels >10 mcg/dl were found to be in remission. Ten of the 52 patients with cortisol >10 mcg/dl by postoperative day 1-2 underwent a second TSS within 7 days. Forty-three patients (82.7%) achieved CD remission (36 after one TSS and 7 after a second early TSS) and six patients suffered disease recurrence (mean 39.2 ± 52.4 months). An immediate second TSS induced additional hormonal deficiencies (diabetes insipidus) in three patients with no surgical complications. Persistent disease was noted in nine patients despite three patients having an immediate second TSS. Positive predictive value for remission of cortisol <2 mcg/dl and ACTH <5 pg/ml was 100%. Cortisol and ACTH levels (at all postoperative time points and at 2 months) were correlated (r = 0.37, P < 0.001). Nadir serum cortisol of ≤2 mcg/dl and ACTH <5 pg/ml predicted remission (P < 0.005), but no level predicted lack of recurrence. Immediate postoperative ACTH/cortisol did not predict length of remission. No patients with postoperative cortisol >10 mcg/dl were observed to have delayed remission; all required additional treatment. There was no significant difference in age, body mass index, tumor size and length of follow-up between postoperative cortisol groups: cortisol ≤2 mcg/dl, cortisol >5 mcg/dl and cortisol >10 mcg/dl. Immediate postoperative cortisol levels should routinely be obtained in CD patients post TSS, until better tools to identify early remission are available. Immediate repeat TSS could be beneficial in patients with cortisol >10 mcg/dl and positive CD pathology: our combined (micro- and macroadenomas) remission rate with this approach was 82.7%. ACTH measurements correlate well with cortisol. However, because no single cortisol or ACTH cutoff value excludes all recurrences, patients require long-term clinical and biochemical follow-up. Further research is needed in this area.

Discordant growth hormone and IGF-1 levels post pituitary surgery in patients with acromegaly naïve to medical therapy and radiation: what to follow, GH or IGF-1 values?

New criteria that define acromegaly remission are more stringent: normal (age/sex-adjusted) insulin-like growth factor type 1 (IGF-1), growth hormone (GH) random (GHr) <1 µg/L, and a GH nadir (GHn) during oral glucose tolerance test (OGTT) of <0.4 µg/L. Discordance between GH and IGF-1 values is often attributed to somatostatin receptor ligands (SRLs) or radiation. The purpose of this study was to evaluate rates of discordant IGF-1 and GH levels in patients with GH secreting adenomas (after pituitary surgery), who were naïve to any other treatment. We retrospectively analyzed data over a 5 year time period (2006-2010), in post-surgery acromegaly patients who had elevated IGF-1 but normal GH levels (per the new cure criteria). Symptoms of acromegaly were scored according to a 4-point scale. Fifty-four patients had post-operative GHr and IGF-1 measurements, 28 patients had GHn during OGTT, and 16 patients had 5-point 2-h GH day curve tests. Thirteen of 54 (24%) patients were found to have intermittent persistent discordant values; high IGF-1 and normal GH at final evaluation (77% of these patients were women). Patients had a median number of IGF-1 evaluations of 7.5 (range: 2-15) over a median of 22 months (range: 3-47 months). Mean elevated IGF-1 in the discordant population was 1.25 × upper limit of normal (ULN) ± 0.17 (range: 1.01-1.6 × ULN). Twelve of the 13 (92%) patients had macroadenomas; 10 of the 13 (69%) patients had mammosomatotroph, mixed lacto/somatotroph tumors or prolactin staining. No patient in the discordant population was on estrogen replacement therapy or had overt cardiac disease. When the relatively asymptomatic discordant population was compared with 35 patients from the concordant population (six were excluded because of preoperative medical treatment for acromegaly), no significant difference between age, gender distribution, body mass index (BMI), presence of diabetes mellitus (DM) or glucose intolerance and adrenal insufficiency between groups was noted. In our study of postoperative patients with acromegaly naïve to both SRLs and radiation, using new GH cut-off levels, 24% had intermittent or persistent discordant values. Our results highlight that relying on IGF-1 or GH measurements alone is not adequate for assessing disease control in surgically treated acromegaly patients. Management of such patients needs to be individualized and long-term studies evaluating morbidity and mortality incorporated into treatment decisions. Further studies with larger patient populations and longer follow-up are required to determine the long-term implications of discordant GH and IGF-1 value patterns.

Single stage transcranial exposure of large dural venous sinuses for surgically-assisted direct transvenous embolization of high-grade dural arteriovenous fistulas: technical note.

BACKGROUND: High-grade dural arteriovenous fistulas (DAVFs) with retrograde cortical leptomeningeal drainage are formidable lesions because of their risk for intracranial hemorrhage. Treatment is aimed at occluding venous outflow to achieve obliteration of the fistula. In DAVFs that involve a large dural venous sinus (transverse sigmoid sinus or superior sagittal sinus), occluding venous outflow can be accomplished endovascularly with transvenous embolization. However, in some cases of DAVFs with reflux into cortical leptomeningeal veins, there may be venous restrictive disease downstream, such as occlusive thrombosis, which can prohibit endovascular access via the transfemoral or transjugular routes. In these instances, a transcranial approach can be performed to expose the large dural venous sinus distal to the site of occlusion for direct catheterization of the venous outflow for transvenous embolization. This combined surgical and endovascular strategy provides direct access to the venous outflow and bypasses the site of thrombotic obstruction. METHODS: In this report, we describe our technique of single stage surgically-assisted transvenous embolization in three patients with high-grade DAVFs involving a large dural sinus. RESULTS: All patients achieved complete obliteration of their DAVFs without any venous related complications. CONCLUSION: Our technique of surgically-assisted direct transvenous embolization of high-grade DAVFs can be successfully performed as a single stage in the operating room with intraoperative angiography and stereotactic image guidance.

Temozolomide for corticotroph pituitary adenomas refractory to standard therapy.

To highlight the potential of temozolomide (TMZ) to induce rapid tumor regression in patients with aggressive corticotroph adenomas (CA) that are refractory to surgery and radiation therapy and to review use of TMZ in other pituitary tumors. We present a case of a 56-year-old male with a 3 cm CA treated with transphenoidal surgery (TSS) and conventional radiotherapy in the same year. His hypercortisolemia recurred 11 years later with rapid tumor growth (to 4.2 × 2.5 cm) and he underwent a second TSS with good resection. The tumor recurred 6 months later with ophthalmoplegia. Over 16 months he underwent an additional three surgeries (two TSS, one craniotomy) and repeated conventional radiotherapy. Ki67 staining index on surgical specimens was 5-6%. Temozolomide is an oral alkylating agent approved for glioblastoma multiforme treatment that has only recently shown promise in treating some pituitary tumors. In this patient TMZ was started at 150 mg/m²/day, titrated to 200 mg/m²/day, taken 5 days per month. The only significant side effect was moderate nausea. After 10 weeks, the tumor showed a remarkable 60% regression with objective improvement in ophthalmoplegia. Treatment of aggressive CAs represents a therapeutic challenge and in some cases surgical debulking and radiotherapy are of limited success. Few reports of CAs responsive to TMZ have been reported in the literature. To our knowledge, this case represents the most rapid robust CA shrinkage response reported to date. Further randomized clinical trials of TMZ in the treatment of aggressive pituitary adenomas are warranted.

Wada test using secobarbital sodium (Ional) to determine language dominance.

The intracarotid sodium amobarbital (Amytal) test, the Wada test, remains an efficient test for evaluation of language and memory function. However, due to a world shortage of amobarbital, it has become necessary to investigate the use of alternatives. We report the efficacy of the Wada test using secobarbital sodium (Ional) in determining language dominance. An accurate determination of language dominance was required in 43 patients preoperatively at our institution. Patients underwent the Wada test using secobarbital sodium, effectiveness and safety were assessed. Patients were monitored for vital signs (blood pressure, respiratory rates, heart rates and saturation of oxygen). Ten patients were further monitored for continuous intra-arterial blood pressure and monitored with scalp electroencephalography (EEG). Language dominance was determined by the Wada test with secobarbital sodium in all patients. Total volume of secobarbital sodium injected was 10-25 mg (mean 16.5 ± 3.2 mg). Changes in vital signs were minimal and any induced neurological deficits completely disappeared within 8 min. On EEG records, induced theta waves immediately appeared on the ipsilateral side of the intra-arterial injection and disappeared within 6 min. One patient described a scintillating scotoma (sensation of shimmering light in his eyes) at the moment of injection; another experienced an epileptic episode during the test and recovered after 6 min. No adverse events were observed in the remaining 41 cases. We propose secobarbital sodium as a safe and reliable alternative to sodium amobarbital used in the Wada test to determine language dominance.

Acromegaly: a review of current medical therapy and new drugs on the horizon.

Acromegaly is a disease that results from a growth hormone (GH)­secreting pituitary tumor. Clinically, the disease is characterized by excessive skeletal growth, soft tissue enlargement with disfigurement, and increased risk of cardiovascular death. The goals of treatment are the removal or reduction of the tumor mass via surgery and normalization of GH secretion. Another treatment goal is the preservation of normal pituitary function if possible. Transsphenoidal surgery by an experienced neurosurgeon is usually the first line of therapy, especially for small tumors. Surgeon expertise is crucial for outcome, with dedicated pituitary surgeons having better results. However, overall cure rates remain low because patients with these tumors usually present at an incurable stage. Therefore, medical therapy to control excess GH secretion plays a significant role in a large proportion of patients with acromegaly who are not cured by surgery or other forms of therapy, such as radiotherapy, and/or are awaiting the effects of radiotherapy. If surgery is not curative, lifelong monitoring and the control of excess GH is usually necessary by a care team experienced in handling this chronic disease. In the past decade major progress has occurred in the development of highly specific and selective pharmacological agents that have greatly facilitated more aggressive management of active acromegaly. Treatment approach should be individualized and take into consideration a patient's tumor size and location, symptoms, comorbid conditions, and preferences. Because a surgical cure can be difficult to achieve, all patients, even those with what seems to be a clinically and biochemically inactive disease, should undergo long-term biochemical testing and pituitary MR imaging.

Cavernous malformations of the optic pathway and hypothalamus: analysis of 65 cases in the literature.

OBJECT: Cavernous malformations (CMs) of the optic pathway and hypothalamus (OPH) are extremely rare. Patients with these lesions typically present with chiasmal apoplexy, characterized by sudden visual loss, acute headaches, retroorbital pain, and nausea. Surgical removal is the recommended treatment to restore or preserve vision and to eliminate the risk of future hemorrhage. However, the anatomical location and eloquence of nearby neural structures can make these lesions difficult to access and remove. In this study, the authors review the literature for reported cases of OPH CMs to analyze clinical and radiographic presentations as well as surgical approaches and neurological outcomes. METHODS: A MEDLINE/PubMed search was performed, revealing 64 cases of OPH CMs. The authors report an additional case in the study, making a total of 65 cases. Each case was analyzed for clinical presentation, lesion location, radiographic features, treatment method, and visual outcome. RESULTS: In 65 patients with OPH CMs, the optic chiasm was affected in 54 cases, the optic nerve(s) in 35, the optic tract in 13, and the hypothalamus in 5. Loss of visual field and acuity was the most common presenting symptom (98%), followed by headache (60%). The onset of symptoms was acute in 58% of patients, subacute in 15%, and chronic progressive in 26%. Computed tomography scans revealed hyperdense suprasellar lesions, with calcification visible in 56% of cases. Magnetic resonance imaging typically demonstrated a heterogeneous lesion with mixed signal intensities suggestive of blood of different ages. The lesion was often surrounded by a peripheral rim of hypointensity on T2-weighted images in 60% of cases. Minimal or no enhancement occurred after the administration of gadolinium. Hemorrhage was reported in 82% of cases. Most patients were surgically treated (97%) using gross-total resection (60%), subtotal resection (6%), biopsy procedure alone (6%), biopsy procedure with decompression (23%), and biopsy procedure followed by radiation (2%). Those patients who underwent gross-total resection had the highest rate of visual improvement (85%). Two patients were treated conservatively, resulting in complete blindness in 1 patient and spontaneous recovery of vision in the other patient. CONCLUSIONS: Cavernous malformations of the OPH are rare and challenging lesions. Gross-total resection of these lesions is associated with favorable visual outcomes. Emergent surgery is warranted in patients presenting with chiasmal apoplexy to prevent permanent damage to the visual pathway.

Optochiasmatic cavernous hemangioma.

We present a case of an optochiasmatic cavernous hemangioma (OCH) treated by stereotactic radiotherapy that required subsequent surgical resection. Subtotal resection and/or radiotherapy are not curative and can lead to hemorrhage and progressive neuronal insult. We recommend complete surgical resection as the treatment of choice.

Significant headache improvement after transsphenoidal surgery in patients with small sellar lesions.

OBJECT: Pituitary adenomas represent a large proportion of brain tumors that are increasing in incidence because of improved imaging techniques. Headache is the primary symptom in patients with large tumors (macroadenomas), but is also a symptom in patients with small tumors (microadenomas, tumors < 1.0 cm). The prevalence and optimal treatment of headaches associated with pituitary tumors is still unclear, particularly in cases of microadenoma. If conventional medical management fails, transsphenoidal surgery (TSS) may be considered as an alternative treatment for intractable headaches. METHODS: The authors conducted a retrospective review of 512 patients who underwent TSS at Oregon Health & Science University between 2001 and 2007; patients with Cushing disease were excluded. The authors identified 41 patients with small pituitary tumors who underwent TSS, and retrospectively evaluated the resolution and/or treatment of headache. RESULTS: Ninety percent of patients who presented with nonfunctioning microadenomas and Rathke cleft cysts experienced resolution or improvement in their headaches after TSS, and 56% of patients who presented with hyperfunctioning pituitary microadenomas had improvement in their headaches. There were no postoperative complications. CONCLUSIONS: In this retrospective study, the authors demonstrate the efficacy of TSS in the treatment of intractable headaches in patients who present with pituitary microadenomas (nonsecreting and hypersecretory) and Rathke cleft cysts.

The role of surgery for high-grade intracranial dural arteriovenous fistulas: importance of obliteration of venous outflow.

OBJECT: Surgical intervention may be required if endovascular embolization is insufficient to completely obliterate intracranial dural arteriovenous fistulas (DAVFs). The authors report their 14-year experience with 23 patients harboring diverse intracranial DAVFs that required surgical intervention. METHODS: Between 1993 and 2007, 23 patients underwent surgery for intracranial DAVFs. The following types of DAVFs were treated: superior petrosal sinus (in 10 patients); parietooccipital (in 3); confluence of sinuses and ethmoidal (in 2 each); and tentorial, falcine, occipital, transverse-sigmoid, superior sagittal, and cavernous sinuses (in 1 patient each). In all cases, the authors' goal was to obliterate the DAVF venous outflow by direct surgical interruption of the leptomeningeal venous drainage. Transarterial embolization was used primarily as an adjunct to decrease flow to the DAVF prior to definitive treatment. RESULTS: Complete angiographic obliteration of the DAVF was achieved in all cases. There were no complications of venous hypertension, venous infarction, or perioperative death. There were no recurrences and no further clinical events (new hemorrhages or focal neurological deficits) after a mean follow-up of 45 months. CONCLUSIONS: The authors' experience emphasizes the importance of occluding venous outflow to obliterate intracranial DAVFs. Those that drain purely through leptomeningeal veins can be safely obliterated by surgically clipping the arterialized draining vein as it exits the dura. Radical excision of the fistula is not necessary.

Modified orbitozygomatic craniotomy for large medial sphenoid wing meningiomas.

Modified orbitozygomatic craniotomy (MOZC) is an anterior lateral skull base approach characterized by simplicity and wide exposure. The approach was first introduced in 2003 and there are few clinical reports. This report details treatment of patients with large (>4 cm) sphenoid wing meningiomas via a MOZC approach, and to the authors' knowledge, the first published in English. Total resection was achieved in all 5 patients in this study. One patient experienced a postoperative epidural hematoma that was successfully treated. All patients returned to daily activity without neurological sequellae. The advantages of MOZC are sparing of the zygomatic arch and removal of the orbital rim; hence, the surgeon can plan a capacious operative field without excessive brain retraction and resect the tumor before opening the dura. The MOZC approach is a clinically feasible, low morbidity, surgical option for paraclinoid lesions, such as large sphenoid wing meningiomas.

Dural arteriovenous fistula of the anterior condylar confluence and hypoglossal canal mimicking a jugular foramen tumor.

The anterior condylar confluence (ACC) is located on the external orifice of the canal of the hypoglossal nerve and provides multiple connections with the dural venous sinuses of the posterior fossa, internal jugular vein, and the vertebral venous plexus. Dural arteriovenous fistulas (DAVFs) of the ACC and hypoglossal canal (anterior condylar vein) are extremely rare. The authors present a case involving an ACC DAVF and hypoglossal canal that mimicked a hypervascular jugular bulb tumor. This 53-year-old man presented with right hypoglossal nerve palsy. A right pulsatile tinnitus had resolved several months previously. Magnetic resonance imaging demonstrated an enhancing right-sided jugular foramen lesion involving the hypoglossal canal. Cerebral angiography revealed a hypervascular lesion at the jugular bulb, with early venous drainage into the extracranial vertebral venous plexus. This was thought to represent either a glomus jugulare tumor or a DAVF. The patient underwent preoperative transarterial embolization followed by surgical exploration via a far-lateral transcondylar approach. At surgery, a DAVF was identified draining into the ACC and hypoglossal canal. The fistula was surgically obliterated, and this was confirmed on postoperative angiography. The patient's hypoglossal nerve palsy resolved. Dural arteriovenous fistulas of the ACC and hypoglossal canal are rare lesions that can present with isolated hypoglossal nerve palsies. They should be included in the differential diagnosis of hypervascular jugular bulb lesions. The authors review the anatomy of the ACC and discuss the literature on DAVFs involving the hypoglossal canal.

Use of frameless stereotactic computed tomography venography for intraoperative localization of dural arterial venous fistulas: case report.

BACKGROUND: The following technical case report illustrates the use of multiple imaging modalities including 3D CTV with frameless stereotactic navigation for intraoperative planning and localization for surgical obliteration of a cranial dAVF with leptomeningeal drainage. CASE DESCRIPTION: This 65-year-old man presented with an asymptomatic occipital dAVF with leptomeningeal drainage. In addition to cerebral angiography, a CTV with 3D reconstruction was performed, which provided excellent visualization of the dAVF and clarified its pattern of drainage. The dAVF was supplied by a middle meningeal artery branch that drained into an occipital cortical vein, which then retrograde filled the vein of Labbé. Frameless stereotactic navigation with the imported CTV images was used to plan the craniotomy and to localize the leptomeningeal draining vein and vein of Labbé. The draining vein of the fistula was successfully ligated and divided while preserving flow in the vein of Labbé. Postoperative angiogram demonstrated complete obliteration of the dAVF. CONCLUSION: Integration of a 3D reconstructed CTV with conventional angiographic information optimized our surgical understanding of the spatial anatomy of this dAVF and its pattern of venous drainage. Applying the CTV with frameless stereotaxy allowed for safe obliteration of the dAVF while preserving the vein of Labbé.

Microsurgical Clipping of an Anterior Communicating Artery Aneurysm Using a Novel Robotic Visualization Tool in Lieu of the Binocular Operating Microscope: Operative Video.

INTRODUCTION: The binocular operating microscope has been the visualization instrument of choice for microsurgical clipping of intracranial aneurysms for many decades. OBJECTIVE: To discuss recent technological advances that have provided novel visualization tools, which may prove to be superior to the binocular operating microscope in many regards. METHODS: We present an operative video and our operative experience with the BrightMatterTM Servo System (Synaptive Medical, Toronto, Ontario, Canada) during the microsurgical clipping of an anterior communicating artery aneurysm. To the best of our knowledge, the use of this device for the microsurgical clipping of an intracranial aneurysm has never been described in the literature. RESULTS: The BrightMatterTM Servo System (Synaptive Medical) is a surgical exoscope which avoids many of the ergonomic constraints of the binocular operating microscope, but is associated with a steep learning curve. The BrightMatterTM Servo System (Synaptive Medical) is a maneuverable surgical exoscope that is positioned with a directional aiming device and a surgeon-controlled foot pedal. While utilizing this device comes with a steep learning curve typical of any new technology, the BrightMatterTM Servo System (Synaptive Medical) has several advantages over the conventional surgical microscope, which include a relatively unobstructed surgical field, provision of high-definition images, and visualization of difficult angles/trajectories. CONCLUSION: This device can easily be utilized as a visualization tool for a variety of cranial and spinal procedures in lieu of the binocular operating microscope. We anticipate that this technology will soon become an integral part of the neurosurgeon's armamentarium.

A novel treatment approach to cholesterol granulomas. Technical note.

The authors report a novel technique for the treatment of cholesterol granulomas. An extradural middle fossa approach was used to access the granuloma, with drainage through silastic tubes into the sphenoid sinus via the anteromedial triangle between V1 and V2. Cholesterol granulomas occur when the normal aeration and drainage of temporal bone air cells is occluded, resulting in vacuum formation and transudation of blood into the air cells. This process results in anaerobic breakdown of the blood with resulting cholesterol crystal formation and an inflammatory reaction. Traditional treatment of this lesion involves extensive drilling of the temporal bone to drain the granuloma cyst and establish a drainage tract into the middle ear. Such drainage procedures can be time consuming and difficult, and potentially involve structural damage to the inner ear and facial nerve. An extradural middle fossa approach provides easy access to the granuloma and anterior petrous bone entry into the granuloma for resection. Granuloma drainage is then achieved using shunt tubing in the sphenoid sinus via a small hole in the anteromedial triangle between V1 and V2. Five patients with symptomatic cholesterol granuloma were treated without complication using this novel extradural middle fossa approach. One patient required reoperation 1-year postoperatively for cyst regrowth and occlusion of the drainage tube. At the 5-year follow-up examination, no patient reported recurrent symptoms. Extradural middle fossa craniotomy and silastic tube drainage into the sphenoid sinus is a viable alternative method for treatment of cholesterol granuloma.

Safety and efficacy of a novel polyethylene glycol hydrogel sealant for watertight dural repair.

OBJECT: The authors prospectively evaluated the safety and efficacy of a novel polyethylene glycol (PEG) hydrogel sealant in patients undergoing elective cranial surgery with documented cerebrospinal fluid (CSF) leakage after sutured dural repair. METHODS: The PEG hydrogel sealant was used at 11 different study sites in 111 patients with documented intraoperative CSF leakage after neurosurgical dural repair for a variety of conditions. Intraoperative CSF leakage was either spontaneous or induced by a Valsalva maneuver. Patients were monitored for 3 months postoperatively with physical examinations, clinical laboratory analyses, and diagnostic imaging. The PEG hydrogel sealant was 100% effective in stopping CSF leakage in all patients. There were no sealant-related adverse events and all clinical outcomes were consistent with expectations for seriously ill patients undergoing prolonged neurosurgical procedures. CONCLUSIONS: The PEG hydrogel sealant provides a safe and effective watertight closure when used as an adjunct to sutured dural repair during cranial surgery.

Spontaneous middle fossa encephalocele and cerebrospinal fluid leakage: diagnosis and management.

OBJECTIVE: To evaluate the clinical presentation, operative findings, and surgical management of patients with spontaneous middle fossa encephalocele (SMFE) and cerebrospinal fluid (CSF) leakage repaired using a middle fossa craniotomy (MFC) approach. STUDY DESIGN: Retrospective. SETTING: Tertiary referral center. PATIENTS: Fifteen consecutive patients with 16 SMFE repaired using an MFC approach between January 1999 and April 2006 were included. INTERVENTIONS: Patients were evaluated clinically and radiologically with computed tomography or magnetic resonance imaging. Encephaloceles were approached via MFC, and the cranial base was repaired in multilayered fashion using a variety of materials, including hydroxyapatite cement. Patients were followed clinically after discharge. MAIN OUTCOME MEASURES: Postoperative complications, including CSF leak and the need for surgical revision, are evaluated. Patient factors, diagnostic testing, and operative findings are reviewed. RESULTS: Diagnosis was made using clinical and radiologic evaluation in most patients. Beta2-transferrin testing was occasionally used in the diagnostic workup. Intraoperatively, multiple defects of the floor of the middle fossa were found in more than half of patients. Fifteen SMFE in 14 patients were successfully repaired via MFC alone. One patient required revision with a combined transmastoid/MFC approach due to recurrent CSF leakage. Hydroxyapatite cement was used for repair of the cranial base in 9 patients without complication. CONCLUSION: An MFC approach can be used to repair SMFE with CSF leakage with a high level of success. Hydroxyapatite cement is a safe and useful adjunct to aid in reconstruction of the cranial base defects in cases of SMFE.