M. N. Pamir

Cervical spondylotic myelopathy: surgical results and factors affecting prognosis.

OBJECTIVE A variety of factors may affect surgical outcome in patients with cervical spondylotic myelopathy. The aim of this study is to determine these factors on the basis of preoperative radiological and clinical data. METHODS To assess the factors affecting postoperative outcome after surgery for cervical spondylotic myelopathy, the clinical and radiological data of 27 patients with cervical spondylotic myelopathy were reviewed. Functional and neurological statuses were assessed using the Japanese Orthopaedic Association (JOA) scale modified by Benzel. In all patients, the effect of age, symptom duration, cervical curvature, presence or absence of preoperative high signal intensity within the spinal cord as revealed by T2-weighted magnetic resonance imaging, and diameters of the spinal canal and vertebral body on pre- and postoperative neurological statuses were investigated. Plain radiographs were obtained for all patients, magnetic resonance images for 21 patients (77.8%), computed tomographic scans for 13 patients (48.1%), myelograms for 6 patients (22.2%), and computed tomographic myelograms for 4 patients (14.8%). There were five patients with a JOA score of 10, six patients with a JOA score of 11, six patients with a JOA score of 12, four patients with a JOA score of 13, four patients with a JOA score of 14, one patient with a JOA score of 15, and one patient with a JOA score of 16. All patients underwent cervical laminectomies. The mean follow-up period was 54.1 months. The final neurological examinations revealed improvement in the JOA scores of 85.1 % of the patients. RESULTS Statistical analysis of all patients revealed mean JOA scores of 12.185 +/- 1.618 and 14.370 +/- 2.15 before surgery and at final examination, respectively. The difference between the preoperative JOA score and the final JOA score was determined to be statistically significant (P < 0.0001). Statistical analyses also showed better neurological improvement in patients younger than 60 years and in patients with normal preoperative cervical lordosis. Although patients without preoperative high signal intensity of the spinal cord showed a better improvement rate than did patients with preoperative high signal intensity, the determined difference was statistically insignificant. CONCLUSION It can be concluded that age and abnormal cervical curvature predict less postoperative neurological improvement. The presence of preoperative high signal intensity within the spinal cord may also reflect less neurological improvement.

Outcome determinants of pterional surgery for tuberculum sellae meningiomas

SummaryBackground. Current literature on tuberculum sellae meningiomas is very heterogenous due to wide variation in nomenclature, diagnostic and operative techniques. The aim of this study is specifically to analyze the results of pterional craniotomy for tuberculum sellae meningiomas. A homogenous cohort of 42 consecutively operated tuberculum sellae meningioma cases are reviewed with special emphasis on the effects of pterional microsurgery on visual outcome. Methods. This is a retrospective clinical analysis. 42 consecutive patients operated upon during the period of 15 years in a single institution using standard imaging protocols and pterional microsurgery are presented and effect of various variables on visual outcome analysed. Findings. 81% of the patients presented with visual symptoms. The mean duration of symptoms was 12 months. Tumour volumes ranged from 7.5 to 210 mm3. A right sided pterional microsurgery was used in all patients. Complete resection rate was 81%. Vision improved in 58%, worsened in 14%. Non-visual morbidity was 7.1% and mortality was 2.4%. The follow up period of patients ranged from 3 to 192 months (median: 30 months). The mean was 37.5 months (SD = ±36.7 months) and a recurrence rate of 2.4% was observed. Conclusions. A standard pterional craniotomy using microsurgical technique provides the necessary exposure enabling total removal while keeping the complications to a minimum. Upon analysis of our findings we found that patient age of more than 60, duration of visual symptoms longer than 1 year, severe visual symptomatology, predominantly vertical growth, presence of significant peri-tumoural oedema, absence of an intact arachnoid plane and subtotal removal were correlated with a dismal visual outcome.

Multimodality management of 26 skull-base chordomas with 4-year mean follow-up: experience at a single institution

SummaryObjective. To analyze a series of patients with pathologically confirmed skull-base chordoma, and to develop an algorithm for the management of this challenging disease based on the data, our experience, and the current literature. Material and methods. Between the years 1986 and 2001, 26 chordoma patients received multimodality treatment with various combinations of conventional surgery, skull-base surgical techniques, and gamma-knife surgery at the Marmara University Faculty of Medicine. A total of 57 procedures (43 tumor excision surgeries, 7 gamma-knife procedures, and 7 other operations to treat complications) were performed. The mean follow-up period was 4 years (48.5 months). Karnofsky scoring was used to follow the patients’ clinical conditions, and magnetic resonance image analysis was used to measure tumor volume over time. Results. Seven patients died during follow-up. Two of the deaths were due to surgical complications, four resulted from clinical deterioration related to tumor recurrence, and one was unrelated to neoplasia. The rate of tumor recurrence after the first surgical treatment was 58%. Residual tumor volume was lower in the cases in whom skull-base approaches were used as first-line management. The 19 survivors showed little change in clinical status from initial diagnosis to the most recent follow-up check. The mean follow-up time after gamma-knife treatment was 23.3 months. During this period, mean tumor volume increased 28% above the mean volume at the time of gamma-knife surgery. The mean Karnofsky score decreased by 6% during the same time frame. Conclusions. The most effective first-line treatment for chordoma patients is surgery. The findings for residual tumor volume indicated that skull-base approaches are the best surgical option, and the complication rates for these techniques are acceptable. However, it is rare that surgery ever biologically eradicates this disease, and the data showed that these chordomas almost always progress if the tumor volume at the time of diagnosis exceeds 20 cm3. Based on our experience and the biological character of the disease, we now advocate radiosurgical treatment (gamma-knife in our case) immediately after the first-line skull-base surgery when the tumor residual volume is <30 cm3.

Pituitary adenomas treated with gamma knife radiosurgery: volumetric analysis of 100 cases with minimum 3 year follow-up.

OBJECTIVE To analyze pituitary adenoma volume changes after gamma knife radiosurgery (GKRS) in patients with 3 years of follow-up and to investigate factors that might affect these changes. METHODS Between January 1997 and March 2004, a total of 1930 patients were treated in the Gamma Knife Unit of the Marmara University Department of Neurosurgery in Istanbul, Turkey. Three hundred sixty of these patients had pituitary adenomas (PAs). This prospectively designed clinical study documents the radiological-volumetric analysis for the first 100 of these patients with PAs who had a minimum of 3 years of follow-up and met the study requirements. Each tumor was assessed with serial magnetic resonance imaging scans after radiosurgery; at each time point, adenoma volume was expressed as a percentage of the tumors initial volume. Volume changes were investigated relative to margin dose, the cavernous sinus infiltration, and endocrinological type of adenoma. RESULTS At the end of the first year after GKRS, the PA volumes had decreased to approximately 90% of the initial volume on average. The corresponding approximate averages for the ends of Years 2 and 3 were 80 and 70% of the initial volume, respectively. At 3 years after GKRS, the PAs in the group with a peripheral dose of less than 17 Gy were reduced to approximately 80% of the initial volume on average. In contrast, the tumors in the patients with marginal doses of 21 to 23 Gy were reduced to approximately 60% of the initial volume at this stage. The adenomas treated with the highest marginal doses (>27 Gy) showed the earliest volume decreases after GKRS (6–9 mo after the procedure). Cavernous sinus noninfiltrating adenomas showed greater volume decreases after GKRS; on average, these masses were reduced to approximately 50% of their initial volume at 3 years. In contrast, the PAs that had infiltrated the cavernous sinus had only dropped to approximately 80% of their initial volume at this stage. The growth hormone-secreting PAs showed the maximum volume decrease with GKRS. On average, these lesions were approximately 60% of their initial volume at the 3-year stage. The nonfunctioning tumors and the prolactin-secreting adenomas showed similar volume changes over time. On average, these tumors had dropped to approximately 75 and 70% of the initial volume, respectively, by 3 years after GKRS. CONCLUSION Gamma knife radiosurgery halts the growth of pituitary adenomas. Cavernous sinus extension and margin dose are the most important determinants of adenoma volume after this type of therapy.

Intraoperative MR imaging: preliminary results with 3 tesla MR system

UNLABELLED Aim of this study is to present the initial clinical experience with 3 tesla intraoperative MR (ioMR). MATERIAL AND METHODS The 3T MRI suite is built adjacent to the neurosurgical operation theatre. The magnet room and the operation theatre are interconnected by a door and both RF-shielded. Before the operation, the magnet (3T Trio, Siemens) and the console rooms are disinfected. Whenever imaging is needed during the operation, the door is opened and the patient is transferred from the operation table to the magnet cradle. Axial, sagittal and/or coronal TSE T2, SE T1 and 3D Flash T1 weighted images (4-6 mm section thickness, 1 mm interslice gap) are obtained according to the lesion. Total examination time is approximately 10 minutes. RESULTS Twenty-six patients were examined with ioMR. There were ten female and seven male patients. Lesions were pituitary adenoma in 10, low grade glial tumor in 9, meningioma and high grade glial tumor in 2 each and metastasis, haemangioblastoma and chordoma in one each. Follow-up time was 1 to 9 months. In 16 patients the first intraoperative examination revealed gross total tumor excision. However, in 10 patients due to tumor remnants surgical intervention was continued and a second examination revealed gross total tumor excision in all. Postoperative routine MR examinations confirmed total tumor excision in all patients. No complication occurred in this series. CONCLUSION This small group of patients examined with ioMR demonstrated that the procedure is simple, helpful in achieving gross total tumor excision without complications.

Radiosurgical treatment of cavernous sinus cavernous haemangiomas.

SummaryBackground. The objective of this report is to evaluate the effects of radiosurgery on cavernous sinus cavernous haemangiomas (CSCHs). Method. Five cases of CSCHs are presented in this report. One of them was diagnosed only neuroradiologically. Other patients underwent surgery and were then referred to Gamma Knife radiosurgery for residual tumours. The cohort consisted of 3 male and 2 female patients with median age of 42 (37–60). The volume of the tumours ranged between 3.8–6.5 cc. They were treated with a marginal dose of 14 to 16 Gy (mean 15 Gy). Findings. In the mean follow-up period of 32 months (6–52 months) all of the tumours decreased in size. There were no complications related to radiosurgery. Conclusion. Gamma Knife radiosurgery is an effective method in the treatment of CSCH, over the period of follow-up described.

Expression of growth factors and structural proteins in chordomas: basic fibroblast growth factor, transforming growth factor alpha, and fibronectin are correlated with recurrence.

OBJECTIVE To test the hypothesis that the expression of certain growth factors and/or structural proteins is correlated with the biological behavior of cranial base chordomas. METHODS The study investigated 14 pathological specimens of cranial base chordomas from patients who were monitored for at least 2 years after their initial operations. Some cases involved multiple tumor recurrences and multiple operations. For those patients, the time to recurrence after each operation was recorded and a mean value was calculated. Nine patients with mean times to recurrence of 24 months or more or with 24 months of follow-up monitoring without recurrence after single operations were designated the “good-prognosis” group. Five patients with mean times to recurrence of less than 24 months were designated the “poor-prognosis” group. In each case, only the specimen from the initial operation was studied. Multiple sequential sections were cut from paraffin-embedded blocks of tissue and immunohistochemically prepared for detection of three growth factors and three structural proteins, i.e., basic fibroblast growth factor, transforming growth factor &agr;, vascular endothelial growth factor, fibronectin, collagen III, and collagen IV. Intensity of expression was graded by using a four-tier system (Grades 0, 1, 2, and 3). Levels of expression of the molecules in the two groups were evaluated and compared. RESULTS The mean transforming growth factor &agr; expression intensity grades for the good- and poor-prognosis groups were 0.8 and 2.6, respectively, and the corresponding mean basic fibroblast growth factor grades were 1.4 and 2.6. For both groups, the mean grade for vascular endothelial growth factor expression was 0.6. For fibronectin, the mean staining grades for the good- and poor-prognosis groups were 2.2 and 3.0, respectively. The corresponding mean intensities for collagen III were 1.1 and 0.8, and those for collagen IV were 2.5 and 2.6. CONCLUSION Our descriptive data from immunohistochemical analyses of chordomas suggest that high levels of transforming growth factor &agr; and basic fibroblast growth factor expression are linked to higher rates of recurrence. Strong fibronectin expression may also be a marker of aggressive biological behavior.

Endovascular treatment increases but gamma knife radiosurgery decreases angiogenic activity of arteriovenous malformations: an in vivo experimental study using a rat cornea model.

OBJECTIVETo compare the angiogenic potentials of embolized, gamma knife–treated or untreated cerebral arteriovenous malformations (AVMs), using a rat cornea angiogenesis model. METHODSTissue samples from cerebral AVM patients who were either untreated or had previously been treated with embolization or gamma knife radiosurgery and who had undergone operations for hemorrhage at the Neurosurgery Department or the Neurological Sciences Institute of Marmara University were used. For the macroscopic evaluation of angiogenesis, tissue samples were inoculated in a micropocket created on the rat eye, and the level of angiogenic activity was graded macroscopically for 15 days, with glioblastoma multiforme and normal brain artery tissues serving as positive and negative controls, respectively. For the other part of the experiment, eyes of another set of rats were inoculated with the study samples only using the same cornea angiogenesis model, in which microvessel count and vascular endothelial growth factor assessment was done at days 3, 7, 11, and 15. RESULTSBased on our macroscopic findings in the cornea angiogenesis model, embolized AVMs exhibited the highest angiogenic activity, followed by untreated AVMs and gamma knife–treated AVMs. Evaluations of vascular endothelial growth factor expression and microvessel counts showed a similar relation among the 3 tissue groups with regard to the level of angiogenic activity, supporting the results of macroscopic examinations. CONCLUSIONThis study, for the first time, provides experimental semiquantitative data to compare the angiogenic potentials of embolized and gamma knife–treated AVM tissues. Embolization may increase angiogenic activity, and gamma knife radiosurgery may decrease it when compared with activity in previously untreated AVMs. These data can be useful to understand why recurrence of AVMs after angiographically demonstrated endovascular occlusion is common but after gamma knife occlusion is rare.

Spinal solitary fibrous tumor: seventh reported case and review of the literature

We present the clinical, radiological, and pathological features of a solitary fibrous tumor in the spinal cord. This case is the seventh spinal solitary fibrous tumor in the literature. The tumor caused clinical symptoms in a 70-year-old female, which indicated compression of the spinal cord. Magnetic resonance imaging showed an intradural extramedullary mass at T3 vertebral level. Surgically, the tumor was firm, in an intradural extramedullary location and attached to the dura. Histologically, the tumor was composed of spindle cells in a collagen-rich matrix but exhibited regional variations. CD34 and vimentin were diffusely positive during immunohistochemical stain testing. The tumor displayed no positive staining for epithelial membrane antigen, cytokeratin, S-100 protein, smooth muscle actin or desmin. The Ki-67 labeling index was low. Solitary fibrous tumors have been found in a variety of locations suggesting that a solitary fibrous tumor has a mesenchymal origin. This rare tumor should be considered in the differential diagnosis of spinal tumors.Spinal Cord (2001) 39, 57–60.

A retrospective review of cervical corpectomy: indications, complications and outcome

Summary.Background. Cervical corpectomy is a common spinal surgery procedure used to decompress the spinal cord in numerous degenerative, traumatic and neoplastic conditions. The aim of this study was to investigate the indications, complications and outcomes in past cervical corpectomy cases at one centre.Method. 72 patients who underwent cervical corpectomy between February 1992 and June 2001 were retrospectively investigated.Findings. The indications for this operation were degenerative spondylitic disease (26 cases; 36.1%), trauma (18 cases; 25%), tumour (11 cases; 15.3%), infection (10 cases; 13.9%), and ossification of the posterior longitudinal ligament (7 cases; 9.7%). Thirty-seven patients (51.4%) underwent one-level corpectomy, and 35 (48.6%) underwent two-level corpectomy. Autografts were used in 13 cases (18.1%) and allografts were used in 59 cases (81.9%). Anterior plate-screw fixation was performed in all cases. There were 31 postoperative complications in 15 (20.8%) patients. Twelve of the complications were surgical, 5 were graft-related, 7 were plating-related, and 7 were medical. Solid bony fusion was achieved in 65 (92.9%) of the 70 surviving patients. The mean follow-up time was 23.4 months. An overall favourable outcome was achieved in 88% of cases.Conclusion. The outcomes in this series indicate that cervical corpectomy is an effective method for treating traumatic lesions, degenerative disease, tumours and infectious processes involving the anterior and middle portions of the cervical spine.