Johnny B. Delashaw

The safety and effectiveness of a dural sealant system for use with nonautologous duraplasty materials

OBJECT The DuraSeal dural sealant system, a polyethylene glycol hydrogel, has been shown to be safe and effective when used with commercial and autologous duraplasty materials. The authors report on the safety and effectiveness of this sealant when used in conjunction with nonautologous duraplasty materials. METHODS In this retrospective, nonrandomized, multicenter study, the safety and efficacy of a dural sealant system was assessed in conjunction with primarily collagen-based nonautologous duraplasty materials in a sample of 66 patients undergoing elective cranial procedures at 3 institutions. This cohort was compared with 50 well-matched patients from the DuraSeal Pivotal Trial who were treated with this sealant system and autologous duraplasty material. RESULTS The key end points of the study were the incidences of CSF leaks, surgical site infections, and meningitis 90 days after surgery. The incidence of postoperative CSF leakage was 7.6% in the study group (retrospective population) and 6.0% in the Pivotal Trial population. The incidence of meningitis was 0% and 4.0% in the retrospective and Pivotal Trial groups, respectively. There were no serious device-related adverse events or unanticipated adverse device effects noted for either population. CONCLUSIONS This study demonstrates that the DuraSeal sealant system is safe and effective when used for watertight dural closure in conjunction with nonautologous duraplasty materials.

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.

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

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 patients 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.

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 patients 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.

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.

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.

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.

Quantitative Anterior and Posterior Clinoidectomy Analysis and Mobilization of the Oculomotor Nerve during Surgical Exposure of the Basilar Apex Using Frameless Stereotaxis

Background Anterior and posterior clinoidectomies have been proposed to augment exposure of the basilar apex. A sequential quantitative benefit analysis offered by these maneuvers has not been reported. Methods Fourteen datasets from eight cadaveric specimens were analyzed. A modified orbitozygomatic frontotemporal craniotomy was performed. The extent of proximal control of the basilar artery was determined through the exposed opticocarotid and carotidoculomotor triangles before and after clinoidectomies and mobilization of the third nerve at the porous oculomotarius. Results Removal of the anterior and posterior clinoids significantly improved proximal basilar artery access (p < 0.012) and increased the opticocarotid triangle and carotidoculomotor triangle areas (p < 0.017). Surgical freedom increased inferosuperiorally in the opticocarotid triangle following anterior clinoidectomy (p < 0.047) and in carotidoculomotor triangle following posterior clinoidectomy (p < 0.047). Mobilization of the third nerve increased surgical freedom in the mediolateral projection of the carotidoculomotor triangle (p < 0.047). Conclusion Anterior and posterior clinoidectomies significantly improved the area of exposure of the opticocarotid triangle, carotidoculomotor triangle, and the exposed length of the basilar artery available for proximal control. This improvement is extremely important for large or giant aneurysms of the upper basilar artery or aneurysms hidden by the posterior clinoid.