Urvashi Upadhyay, Rami O. Almefty, Ian F. Dunn and Ossama Al-Mefty
Rami Almefty, Ian F. Dunn, Svetlana Pravdenkova, Mohammad Abolfotoh and Ossama Al-Mefty
The relentless natural progression of petroclival meningiomas mandates their treatment. The management of these tumors, however, is challenging. Among the issues debated are goals of treatment, outcomes, and quality of life, appropriate extent of surgical removal, the role of skull base approaches, and the efficacy of combined decompressive surgery and radiosurgery. The authors report on the outcome in a series of patients treated with the goal of total removal.
The authors conducted a retrospective analysis of 64 cases of petroclival meningiomas operated on by the senior author (O.A.) from 1988 to 2012, strictly defined as those originating medial to the fifth cranial nerve on the upper two-thirds of the clivus. The patients' average age was 49 years; the average tumor size (maximum diameter) was 35.48 ± 10.09 mm (with 59 tumors > 20 mm), and cavernous sinus extension was present in 39 patients. The mean duration of follow-up was 71.57 months (range 4–276 months).
In 42 patients, the operative reports allowed the grading of resection. Grade I resection (tumor, dura, and bone) was achieved in 17 patients (40.4%); there was no recurrence in this group (p = 0.0045). Grade II (tumor, dura) was achieved in 15 patients (36%). There was a statistically significant difference in the rate of recurrence with respect to resection grade (Grades I and II vs other grades, p = 0.0052). In all patients, tumor removal was classified based on postoperative contrast-enhanced MRI, and gross-total resection (GTR) was considered to be achieved if there was no enhancement present; on this basis, GTR was achieved in 41 (64%) of 64 patients, with a significantly lower recurrence rate in these patients than in the group with residual enhancement (p = 0.00348). One patient died from pulmonary embolism after discharge.
The mean Karnofsky Performance Status (KPS) score was 85.31 preoperatively (median 90) and improved on follow-up to 88, with 30 patients (47%) having an improved KPS score on follow-up. Three patients suffered a permanent deficit that significantly affected their KPS. Cerebrospinal fluid leak occurred in 8 patients (12.5%), with 2 of them requiring exploration. Eighty-nine percent of the patients had cranial nerve deficits on presentation; of the 54 patients with more than 2 months of follow-up, 21 (32.8%) had persisting cranial nerve deficits. The overall odds of permanent cranial nerve deficit of treated petroclival meningioma was 6.2%. There was no difference with respect to immediate postoperative cranial nerve deficit in patients who had GTR compared with those who had subtotal resection.
Total removal (Grade I or II resection) of petroclival meningiomas is achievable in 76.4% of cases and is facilitated by the use of skull base approaches, with good outcome and functional status. In cases in which circumstances prevent total removal, residual tumors can be followed until progression is evident, at which point further intervention can be planned.
Marcio S. Rassi, Sashank Prasad, Anil Can, Svetlana Pravdenkova, Rami Almefty and Ossama Al-Mefty
Although meningiomas frequently involve the optic nerve, primary optic nerve sheath meningiomas (ONSMs) are rare, accounting for only 1% of all meningiomas. Given the high risk of vision loss with these tumors, surgical intervention is seldom considered, and radiation or observation is commonly applied. Here, the authors describe the visual outcomes for a series of patients who were treated with surgery aiming at maximal tumor resection and highlight their prognostic factors.
The authors retrospectively analyzed the data for 8 patients with intracanalicular ONSMs who had been surgically treated by the senior author (O.A.) between 1998 and 2016. Meningiomas extending into the optic canal from the intracranial cavity (i.e., clinoid, sphenoid wing, tuberculum sellae, diaphragma sellae) were excluded. Diagnosis was based on ophthalmological, radiological, and intraoperative findings, which were confirmed by the typical histological findings. Preoperative, postoperative, and follow-up visual assessments were performed by neuro-ophthalmologists in all cases.
The patients included 7 females and 1 male. The mean age at diagnosis was 45.1 years (range 25.0–70.0 years). Mean duration of follow-up was 38.9 months (range 3.0–88.0 months). All patients reported visual complaints, and all had objective evidence of optic nerve dysfunction. Their evaluation included visual field, visual acuity, funduscopy, and retinal fiber thickness. Total resection was obtained in 4 cases. Comparing preoperative and postoperative visual function revealed that 4 patients had improvement at the last follow-up, 1 patient had stable vision, and 3 patients had decreased function but none had total vision loss. All patients with good preoperative visual acuity maintained this status following surgical treatment. There was no surgical mortality or infection. Operative complications included binocular diplopia in 4 patients, which remitted spontaneously.
Surgery can play a beneficial role in the primary treatment of ONSM, especially lesions located in the posterior third of the nerve. Total removal can be achieved with vision preservation or improvement, without major surgical complications, especially at early stages of the disease. Patients with good preoperative vision and CSF flow in the optic sheath have better chances of a favorable outcome than those with poor vision.
Report of 4 cases
Rami Almefty, Kenan I. Arnautović and Bruce L. Webber
✓ Synovial cysts of the thoracic spine are quite rare. Bilateral presentation is even less frequent, and to the authors' knowledge multilevel occurrence and consistent calcification have not been reported so far. The pathogenesis of these cysts is unknown and their histological features have not been studied. They may be overlooked as the cause of myelopathy. The authors report a series of 4 cases of bilateral, multilevel, consistently calcified thoracic synovial cysts. The details of clinical, radiological, and histological findings are presented, along with a review of the literature, and a hypothesis on the pathogenesis of these lesions is formulated based on results of the clinical and pathological studies performed in these patients.
Rami Almefty, Bruce L. Webber and Kenan I. Arnautović
✓Intraneural perineurioma is a true but rare neoplasm that originates from perineurial cells and mainly affects peripheral nerves. It must be distinguished from other hypertrophic neuropathies that are either inflammatory or demonstrate an onion-bulb formation that originates from Schwann cells. Complying with this strict definition, only three additional cases of cranium-related perineurioma have been identified: two lesions arose extracranially and involved cranial nerves, and one occurred intracranially but did not involve a nerve.
The authors describe a 27-year-old woman who presented with left third cranial nerve palsy and was found to harbor a mass lesion in the superior orbital fissure and cavernous sinus. After subtotal resection had been performed, pathological studies confirmed the presence of perineurial tumor cells in a pseudo–onion bulb formation. The cells stained positively for epithelial membrane antigen but not for S100 protein, clearly distinguishing the disease from one that originates in Schwann cells.
Rami O. Almefty, Tammy L. Tyree, David J. Fusco, Stephen W. Coons and Peter Nakaji
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 patient's 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 patient's 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.
Evgenii Belykh, Ting Lei, Sam Safavi-Abbasi, Kaan Yagmurlu, Rami O. Almefty, Hai Sun, Kaith K. Almefty, Olga Belykh, Vadim A. Byvaltsev, Robert F. Spetzler, Peter Nakaji and Mark C. Preul
Microvascular anastomosis is a basic neurosurgical technique that should be mastered in the laboratory. Human and bovine placentas have been proposed as convenient surgical practice models; however, the histologic characteristics of these tissues have not been compared with human cerebral vessels, and the models have not been validated as simulation training models. In this study, the authors assessed the construct, face, and content validities of microvascular bypass simulation models that used human and bovine placental vessels.
The characteristics of vessel segments from 30 human and 10 bovine placentas were assessed anatomically and histologically. Microvascular bypasses were performed on the placenta models according to a delineated training module by “trained” participants (10 practicing neurosurgeons and 7 residents with microsurgical experience) and “untrained” participants (10 medical students and 3 residents without experience). Anastomosis performance and impressions of the model were assessed using the Northwestern Objective Microanastomosis Assessment Tool (NOMAT) scale and a posttraining survey.
Human placental arteries were found to approximate the M2–M4 cerebral and superficial temporal arteries, and bovine placental veins were found to approximate the internal carotid and radial arteries. The mean NOMAT performance score was 37.2 ± 7.0 in the untrained group versus 62.7 ± 6.1 in the trained group (p < 0.01; construct validity). A 50% probability of allocation to either group corresponded to 50 NOMAT points. In the posttraining survey, 16 of 17 of the trained participants (94%) scored the model's replication of real bypass surgery as high, and 16 of 17 (94%) scored the difficulty as “the same” (face validity). All participants, 30 of 30 (100%), answered positively to questions regarding the ability of the model to improve microsurgical technique (content validity).
Human placental arteries and bovine placental veins are convenient, anatomically relevant, and beneficial models for microneurosurgical training. Microanastomosis simulation using these models has high face, content, and construct validities. A NOMAT score of more than 50 indicated successful performance of the microanastomosis tasks.