David J. Fusco

Comparison of dural grafts in Chiari decompression surgery: Review of the literature.

Background: Decompression of Chiari malformation is a common procedure in both pediatric and adult neurosurgery. Although the necessity for some bony removal is universally accepted, other aspects of Chiari surgery are the subject of debate. The most controversial points include the optimal amount of bony removal, the use of duraplasty (and the type of material), the need for subarachnoid dissection, and the need for tonsillar shrinkage. Material and Methods: We critically reviewed the literature to elucidate the risks and benefits of different graft types and to clarify optimal treatment options therein. Based on our search results, 108 relevant articles were identified. With specific inclusion and exclusion criteria, we noted three studies that directly compared two tlpes of dural substitutes in Chiari malformation surgery. Results: Our review did not support the superiority of either autologous or nonautologous grafts when duraplasty is employed. Our institutional experience, however, dictates that when the pericranium is available and of good quality, it should be utilized for duraplasty. It is non-immunogenic, inexpensive, and capable of creating a watertight closure with the dura. Conclusions: Discrepancies between the three comparative studies analyzed are likely attributable to increases in pericranial quality and thickness with maturity. Future randomized studies with large numbers and the power to resolve differences in the relatively low rates of complications in Chiari surgery are warranted.

Eagle’s syndrome: embryology, anatomy, and clinical management

BackgroundEagle’s syndrome refers to a rare constellation of neuropathic and vascular occlusive symptoms caused by pathologic elongation or angulation of the styloid process and styloid chain. First described in 1652 by Italian surgeon Piertro Marchetti, the clinical syndrome was definitively outlined by Watt Eagle in the late 1940s and early 1950s.MethodsThis article reviews how underlying embryologic and anatomic pathology predicts clinical symptomatology, diagnosis, and ultimately treatment of the syndrome.ResultsThe length and direction of the styloid process and styloid chain are highly variable. This variability leads to a wide range of relationships between the chain and the neurovascular elements of the neck, including cranial nerves 5, 7, 9, and 10 and the internal carotid artery. In the classic type of Eagle’s syndrome, compressive cranial neuropathy most commonly leads to the sensation of a foreign body in the throat, odynophagia, and dysphagia. In the carotid type, compression over the internal carotid artery can cause pain in the parietal region of the skull or in the superior periorbital region, among other symptoms.ConclusionsCareful recording of the history of the present illness and review of systems is crucial to the diagnosis of Eagle’s syndrome. After the clinical examination, the optimal imaging modality for styloid process pathology is spiral CT of the neck and skull base. Surgical interventions are considered only after noninvasive therapies have failed, the two most common being intraoral and external resection of the styloid process.

Comparison of two antibiotic-impregnated ventricular catheters: a prospective sequential series trial.

BACKGROUND: External ventricular drains (EVDs) are valuable adjuncts in the management of neurosurgical patients but are associated with a significant risk of cerebrospinal fluid (CSF) infection (range, 0% to 27%); a review of 23 studies reported a mean of 8.8%. OBJECTIVE: To compare the efficacy of 2 different antibiotic-impregnated EVD catheters in preventing CSF infections. METHODS: Patients were prospectively enrolled in an Institutional Review Board–approved study. During alternating 3-month periods, all patients received either a minocycline/rifampin-impregnated (M/R) ventricular catheter or a clindamycin/rifampin-impregnated (C/R) EVD catheter. CSF cultures were collected at the time of insertion and twice weekly. Positive cultures were defined a priori as growth of the same bacteria on 2 media (eg, blood agar and broth) or 2 cultures of the same bacteria on 1 medium (eg, broth). RESULTS: Altogether, 129 patients (mean age, 58.4 years; 55 male) received 65 C/R catheters and 64 M/R catheters. The most common indications for EVD placement were aneurysmal subarachnoid hemorrhage (48.1%), spontaneous intraparenchymal hemorrhage (13.2%), and tumor (11.6%). The mean duration of ventriculostomy drainage was 11.8 and 12.7 days in the C/R and M/R groups, respectively. No positive CSF cultures were identified in either cohort. CONCLUSIONS: The use of antibiotic-impregnated catheters was associated with an extremely low risk of CSF infection compared with the reported mean of nearly 9% for standard EVD catheters. Infection rates for both C/R and M/R EVD catheters were zero. These results support the use of antibiotic-impregnated EVD catheters in routine clinical practice.

Survival and Functional Outcome After Surgical Resection of Intramedullary Spinal Cord Metastases

OBJECTIVE Intramedullary spinal cord metastasis (ISCM) is a rare manifestation of systemic cancer and data about the optimal management of these lesions are lacking. To clarify the role of surgery, we investigated survival and neurological outcomes after surgical resection of ISCMs. METHODS Between 2003 and 2010, we surgically treated 10 ISCMs in 9 patients. For each patient, we retrospectively collected the following data: demographic variables, history of prior cancer, site of primary cancer, extent of cancer on presentation, degree of resection, preoperative and postoperative spinal cord impairment (American Spinal Injury Association [ASIA] grade), and postoperative survival. We investigated the relationship between these variables, overall survival, and preservation of function. RESULTS Eight ISCMs were treated with gross total resection and two were treated with subtotal resection. Overall postoperative survival was 6.4 ± 9.4 months (mean ± standard deviation), with one patient still alive at last follow-up. Patients with a diagnosis of melanoma had higher mean survival than those with nonmelanoma histology (20.5 ± 13.4 vs. 2.4 ± 1.7 months, P < 0.01). Degree of resection, number of organ systems affected, ambulatory status, and ASIA grade pre operatively or postoperatively, were not significantly associated with survival. Of the nine patients, seven (78%) demonstrated no change in ASIA grade postoperatively, one (11%) improved, and one patient (11%) deteriorated. All patients who were ambulatory preoperatively remained ambulatory postoperatively and at last follow-up. CONCLUSIONS Although ISCM is associated with poor prognosis, survival appears to be greater in patients with melanoma. Surgical resection does not appear to significantly lengthen survival but may be indicated to preserve ambulatory status in symptomatic patients.

Endoscopic Resection of Colloid Cysts: Use of a Dual-Instrument Technique and an Anterolateral Approach

OBJECTIVE Endoscopic approaches are increasingly utilized to treat third ventricular colloid cysts but have been associated with lower rates of complete cyst wall resection. Our objective was to assess the results of colloid cyst resection via an anterolateral endoscopic approach with a dual-instrument technique, with an emphasis on completeness of cyst wall resection. METHODS A retrospective review of the senior authors experience with 22 colloid cysts treated with endoscopic resection since 2004 was performed. Initial cyst size, completeness of resection, postoperative radiographic residual, recurrence at follow-up, need for reoperation, and neurologic morbidity were assessed. All cysts were approached from an anterolateral trajectory with two instruments working in concert through a single endoscope. RESULTS Of 22 patients, near-total resection was obtained in 95%. In 3 cases, a very small, radiographically occult residual was left. Complete cyst wall resection was therefore obtained in 18 (82%). There were no cases of recurrence at follow-up in any patient. No patients required craniotomy or underwent re-resection. Fifteen of 16 (94%) patients with long-term clinical follow-up remained stable or improved. CONCLUSION High rates of complete colloid cyst resection, with low morbidity, are possible with an anterolateral endoscopic approach with dual-instrument technique. These results support the findings of other endoscopists that show how technical modifications to traditional endoscopic approaches can produce favorable results.

Supracerebellar infratentorial endoscopically controlled resection of pineal lesions: case series and operative technique

OBJECT The heterogeneous clinical manifestations and operative characteristics of pathological entities in the pineal region represent a significant challenge in terms of patient selection and surgical approach. Traditional surgical options have included endoscopic transventricular resection; open supratentorial microsurgical approaches through the midline, choroidal fissure, lateral ventricle, and tentorium; and supracerebellar infratentorial (SCIT) approaches through the posterior fossa. The object of the current study was to review the preoperative characteristics and outcomes for a cohort of patients treated purely via the novel endoscopically controlled SCIT approach. METHODS A single-institution series of 9 consecutive patients (4 male and 5 female patients [10 total cases]; mean age 21 years, range 6-37 years) treated via the endoscopically controlled SCIT approach for a pathological entity in the pineal region was retrospectively reviewed. The mean follow-up time was 13.2 months. RESULTS The endoscopically controlled SCIT approach was successfully used to approach a variety of pineal lesions, including pineal cysts (6 patients), epidermoid tumor, WHO Grade II astrocytoma (initial biopsy and recurrence), and malignant mixed germ cell tumor (1 patient each). Gross-total resection and/or adequate cyst fenestration was achieved in 8 cases. Biopsy with conservative debulking was performed for the single case of low-grade astrocytoma and again at the time of recurrence. The mean preoperative tumor and cyst volumes were 9.9 ± 4.4 and 3.7 ± 3.2 cm(3), respectively. The mean operating times were 212 ± 71 minutes for tumor cases and 177 ± 72 minutes for cysts. Estimated blood loss was less than 150 ml for all cases. A single case (pineal cyst) was converted to an open microsurgical approach to enhance visualization. There were no operative complications, as well as no documented CSF leaks, additional CSF diversion procedures, or air emboli. Seven patients underwent concomitant third ventriculostomy into the quadrigeminal cistern. At the time of the last follow-up evaluation, all patients had a stable or improved modified Rankin Scale score. CONCLUSIONS The endoscopically controlled SCIT approach may be used for the biopsy and resection of appropriately selected solid tumors of the pineal region, in addition to the fenestration and/or resection of pineal cysts. Preoperative considerations include patient presentation, anticipated disease and vascularity, degree of local venous anatomical distortion, and selection of optimal paramedian trajectory.

Malignant Transformation of a Vestibular Schwannoma After Gamma Knife Radiosurgery

OBJECTIVE To report a single case of malignant transformation of a vestibular schwannoma after radiosurgery and review the growing body of literature describing patients with malignant transformation of primary benign tumors after radiosurgery, including vestibular schwannoma. METHODS A 46-year-old woman presented with right facial paresthesias and imaging consistent with a right-sided vestibular schwannoma (volume approximately 18.5 cm(3)). RESULTS The patient underwent subtotal resection followed by Gamma Knife radiosurgery (GKRS) 6 months after surgery. Initial histology showed a benign vestibular schwannoma with an MIB-1 labeling index of 5.7%. At 43 months after GKRS, the patient underwent repeat subtotal resection of a benign vestibular schwannoma (MIB-1 labeling index 7.4%). At 59 months after GKRS, she underwent a third resection, and histology showed frank malignant transformation (MIB-1 labeling index 33.8%). CONCLUSIONS Malignant vestibular nerve tumors are extremely rare; only 18 cases have been reported in the literature. Our patient is the sixth pathologically confirmed case of malignant transformation after radiosurgery, supporting the contention that radiosurgery itself may play a causative role in transformation. In a histologically benign lesion, the presence of an elevated MIB-1 labeling index may predispose toward malignant transformation in the setting of adjuvant radiosurgery.

Primary histiocytic sarcoma of the brain mimicking cerebral abscess

Histiocytic sarcoma is a rare malignancy with only 10 reports confirmed primarily involving the CNS. The diagnosis is dependent on the finding of malignant cells with histiocytic morphology and immunophenotype. The authors report a case of pathologically proven HS of the CNS. A 16-year-old boy presented with headaches, emesis, and altered sensorium. Noncontrast head CT scanning demonstrated a left parietal mass consistent with a tumor. Surgery was undertaken. Intraoperative findings revealed green-yellow exudates consistent with an abscess. Cultures were obtained and broad-spectrum antibiotics were started. The patient subsequently underwent multiple surgical procedures, including drainage and debulking of abscesses and hemicraniectomy. Two months after initial presentation, the patients diagnosis of histiocytic sarcoma was confirmed. Pathological examination demonstrated necrotizing inflammation with preponderant neutrophil infiltration, variably atypical mononuclear and multinucleate histiocytes, and numerous mitoses. Additional immunohistochemistry studies confirmed immunoreactivity for CD68, CD45, CD45RO, and CD15 and were negative for CD3, CD20, melanoma cocktail, CD30, CD1a, CD34, HMB-45, and melan-A. Once the diagnosis of histiocytic sarcoma was confirmed, antibiotics were stopped and radiation therapy was undertaken. Despite treatment, the patients neurological status continued to decline and the patient died 126 days after initial presentation. This case represents a rare confirmed example of CNS histiocytic sarcoma. A profound inflammatory infiltrate seen on pathology and green exudates seen intraoperatively make the condition difficult to distinguish from an abscess. Immunohistochemistry showing a histiocytic origin and negative for myeloid, dendritic, or other lymphoid markers is essential for the diagnosis. Further research is needed to establish consensus on treatment.

Cervical and Lumbar Spinal Arthroplasty: Clinical Review

SUMMARY: In contrast to cervical and lumbar fusion procedures, the principal aim of disk arthroplasty is to recapitulate the normal kinematics and biomechanics of the spinal segment affected. Following decompression of the neural elements, disk arthroplasty allows restoration of disk height and maintenance of spinal alignment. Based on clinical observations and biomechanical testing, the anticipated advantage of arthroplasty over standard arthrodesis techniques has been a proposed reduction in the development of symptomatic ALD. In this review of cervical and lumbar disk arthroplasty, we highlight the clinical results and experience with standard fusion techniques, incidence of ALD in the population of patients with surgical fusion, and indications for arthroplasty, as well as the biomechanical and clinical outcomes following arthroplasty. In addition, we introduce the devices currently available and provide a critical appraisal of the clinical evidence regarding arthroplasty procedures.

Surgical Considerations for Intraventricular Meningiomas

n a recent issue of WORLD NEUROSURGERY, Ma et al. provide a retrospective clinical review of 43 patients who underwent I craniotomy for trigone meningioma between 2007 and 2012. All surgeries were performed by the senior author (S.L.) at one facility. In their cohort, 88% of patients presented with associated symptoms, 93% of tumors were World Health Organization (WHO) grade I, and 100% of patients received gross total resection. The investigators used intraoperative ultrasound to identify an appropriate trans-sulcal approach corridor, feeding vasculature, and residual tumor. Of the symptomatic patients, 82% noted symptom improvement at follow-up (range, 2e72 months). Complications included epidural hematoma in 2 patients and malignant intracranial hypertension requiring craniectomy in 1 patient. Although 84% of their patients received an external ventricular drain, only 2 patients ultimately required a ventriculoperitoneal shunt.