Mehmet Yasar Kaynar

A comparison of the clinical profile of cavernous malformations with and without associated venous malformations.

OBJECTIVEnLittle is known about the clinical behavior of cavernous malformations (CMs) associated with venous malformations (VMs) of the brain. The aim of this study is to compare the clinical profile of patients harboring CMs with and without associated VMs.nnnMETHODSnA retrospective analysis of 55 consecutive patients harboring CMs of the brain who presented to a single neurovascular team during a 4-year period was performed. Forty-two patients (76%) had CMs alone (CM group), and 13 patients (24%) had CMs associated with VMs (CM + VM group). Detailed clinical information regarding each patient was gathered. Statistical analysis was performed using Fishers exact test for binary variables and Mann-Whitney U test for continuous variables.nnnRESULTSnThe lesion location was infratentorial for 19 of the 70 CMs (27%) in the CM group and for 14 of the 21 CMs (67%) in the CM + VM group (P = 0.001). Familial histories of CMs were documented for 7 of the 42 patients (17%) in the CM group and none of the 13 patients in the CM + VM group. There was a female-to-male gender bias of 1.6:1 in the CM group and 3.3:1 in the CM + VM group. Sixteen of the 42 patients (38%) in the CM group and 8 of the 13 patients (62%) in the CM + VM group presented with symptomatic hemorrhage. Seizure presentation was documented in 11 of the 42 patients (26%) in the CM group and in 1 of the 13 patients (8%) in the CM + VM group. Repeated symptomatic hemorrhage was diagnosed in 4 of the 42 patients (9.5%) in the CM group and in 3 of the 13 patients (23%) in the CM + VM group. There were no apparent differences in the mean age at presentation, lesion size, or multiplicity between the two groups.nnnCONCLUSIONnPatients with CMs associated with VMs are more likely to be female patients, have associated symptomatic hemorrhage, have lesions in the posterior fossa (statistically significant), suffer from repeated symptomatic hemorrhage, and are less likely to present with seizures or to have familial histories when compared with patients with CMs alone. The possible mechanisms for these apparent differences in clinical profile are discussed.

Duraplasty Using Autologous Fascia Lata Reenforced by On-site Pedicled Muscle Flap: Technical Note

Objective Postoperative cerebrospinal fluid (CSF) leak is a common complication in the practice of neurosurgery, and various surgical techniques were described to overcome and manage this problem. Besides not applying watertight closure of the duraplasty, the inviability and the poor vascularization of the graft and/or the dura (eg, reoperations, multiple operations, or cranial radiotherapy) may lead to delayed healing of the suture site and resultant persistent CSF leaks. We present a simple technique that uses on-site muscle flap with pedicle to supply and vascularize the autologous fascia lata, preserving the viability of the graft and reenforcing its healing ability. Methods We applied this technique in 6 patients with postoperative CSF leaks. After harvesting a fascia lata graft with appropriate size from the patients, the graft was sutured to dural defect in watertight fashion. The suboccipital, temporal, and temporal muscles in 4 patients who had posterior fossa duraplasty, in 1 patient who had pterional craniotomy, and in 1 patient who had subtemporal craniotomy, respectively, were dissected, stretched, and sutured to the fascia graft covering the dura graft suture site and then reinforced by Tisseel fibrin glue (Baxter Healthcare Corporation, Deerfield, IL). Postoperatively, CSF lumbar drain was kept open for 72 hours with pressure wound dressing. The technical nuances are illustrated. Results Cerebrospinal fluid leaks were controlled successfully in 5 patients without recurrence. One patient with posterior fossa duraplasty had recurrence of CSF leak that required reexploration 21 days after the first surgery and a second dural repair in a site distant from the fascia lata attachment. During reexploration intraoperatively, the fascia lata graft was inspected and studied, which has shown the healing of the dura graft site and the graft neovascularization. Conclusions Duraplasty using autologous fascia lata reenforced by on-site pedicled muscle flap is an effective technique to control CSF leak, especially when dura is poorly vascularized and less viable. The unfortunate recurrence of CSF leak and reexploration in the seventh patient helped us to observe the effectively healed dural defect with profound early postoperative vascularization of the graft, supporting our idea about the effectiveness of this technique.

Preliminary experience with precipitating hydrophobic injectable liquid in brain arteriovenous malformations

Advancement in microcatheter design and emergence of new embolic agents offer better results in endovascular treatment of brain arteriovenous malformations (AVMs). Precipitating hydrophobic injectable liquid (PHIL) (Microvention) is a newly introduced dimethyl sulfoxide-based embolic agent for endovascular use. Herein, we present three patients who underwent endovascular treatment of brain AVMs with PHIL, followed by surgical resection. Endovascular features and same-day surgical handling of the new embolic agent PHIL are presented along with histopathologic changes in the acute stage in brain AVMs are presented, and its major differences from Onyx. In our series, PHIL had moderate inflammatory reaction in the acute stage without any associated angionecrosis that is different than Onyx which cause mild inflammatory reaction with angionecrosis. Smallest vessel containing PHIL was 2.9 μm compared to 5 μm with Onyx, which suggests better penetration.

YKL-40 levels in the cerebrospinal fluid and serum of patients with aneurysmal subarachnoid hemorrhage: Preliminary results

YKL-40 is a newly discovered matrix protein thought to be secreted during the acute stages of inflammation. Clinical studies have revealed that YKL-40 has growth factor and potent migration factor activity for cells involved in inflammation and tissue remodeling processes. It has recently been speculated that YKL-40 may serve as a specific serologic marker of neutrophil function at the site of acute tissue inflammation. We aimed to quantify the levels of YKL-40 in both cerebrospinal fluid and serum of ten consecutive patients with aneurysmal subarachnoid hemorrhage and to speculate on the origin of this glycoprotein. The levels were also compared with ten control patients with hydrocephalus. We found that patients with aneurysmal subarachnoid hemorrhage had significantly higher YKL-40 levels in both cerebrospinal fluid and serum than controls. The authors believe that YKL-40 is expressed in cerebrospinal fluid due to stress on neural structures while a damaged blood-brain barrier allows entry of neutrophils and macrophages from the systemic circulation.

An experimental model of traumatic nasoethmoidal cerebrospinal fluid fistula.

Cerebrospinal fluid fistula secondary to head trauma is a potentially dangerous problem and precise localization and radical treatment is mandatory. The diagnostic technique is either computed tomography cisternography or MR cisternography. For evaluating the safety of diagnostic modalities and efficacy of treatment especially in terms of surgery, animal studies demonstrating traumatic cerebrospinal fistula model are indispensable not only for neurosurgeons but also for neuroradiologists. The authors in this paper describe a traumatic cerebrospinal fistula in an animal model using rabbits. The cerebrospinal fluid leakage was demonstrated successfully in all eight rabbits and was verified by computed tomography cisternography. The results led us to conclude that rabbit model of traumatic cerebrospinal fluid fistula is safe and has low mortality and morbidity rates. Further studies including larger number of animals should be considered in order to verify safety more accurately.

Polymorphisms in the matrix metalloproteinase-9 promoters and susceptibility to glial tumors in turkey

AIMnEvidence suggests an association between MMP-9 functional gene polymorphisms and several tumors. The aim of this study was to investigate the possible role of single-nucleotide polymorphisms (SNP) at MMP-9 R279Q A/G, P574R G/C and R668Q G/A and R668Q (rs17577) genotypes with glial tumors in Turkey.nnnMATERIAL AND METHODSnThe present series consisted of tissue samples obtained from 100 cancer-free controls and 100 patients who had undergone glial tumor resection from 2007 to 2011 at the Cerrahpasa Medical Faculty of Istanbul University. Blood samples were collected to extract the genomic deoxyribonucleic acid (DNA) of each subject by polymerase chain reaction (PCR) and DNA sequencing. The genotypes of MMP-9 P574R, R279Q and R668Q SNPs were determined by using the PCR-RFLP assay. Genotypic distributions between patient and control groups were compared for correlations with glial tumor occurrence.nnnRESULTSnSNPs in MMP-9 were not found to be significantly associated with glial tumor risk among participants except R279Q (G-G) which showed high risk only in multivariate analysis (OR adjusted, 3.15 95% CI, 1.10-9.01). The comparisons between the grade of tumor and the genotypic polymorphisms also showed no significant associations in the case group (all p values > 0.05).nnnCONCLUSIONnThe current study showed a significant association between the R279Q G/G polymorphism and formation of glial tumor in advanced age. Changed protein features may cause triggering of some subcellular mechanisms that may have a role in activating oncogenic processes over the years. These data add to the growing epidemiological and experimental evidence that MMP-9 may play a role in glial tumors.

Clipping and Coiling of Intracerebral Aneurysms: A Cost Analysis From a Developing Country

The purpose of this study was to compare cost-effectiveness between coiling and clipping in patients with ruptured or unruptured cerebral aneurysms during their hospital stay. The authors conducted a retrospective analysis of patients with cerebral aneurysms that were treated by clipping or coiling at Cerrahpasa Medical Faculty Hospital during a 1-year period. Direct hospital-based costs and physicians’ fees were calculated and compared between the 2 groups. A total of 76 patients had clipping, and 65 underwent coiling. There were no differences with regard to age or sex in both groups. When comparing major cost categories between the 2 groups, including laboratory tests, medications, blood and blood derivatives, physicians’ fees, surgical/embolization supplies, hospital stay, and imaging, a highly statistically significant difference was found in all major cost categories (P < 0.001). The results showed that although coiling allows a shorter hospital stay and results in a low complication rate, the high cost of single-use medical supplies (eg, coil, microcatheters) increased the cost per patient considerably.

Investigation of Survivin Gene Polymorphism and Serum Survivin Levels in Patients with Brain Tumors

Background/Aim: The single nucleotide polymorphism -31C/G identified in the survivin gene promoter seems to be associated with over-expression of survivin, an anti-apoptotic protein. In gliomas, increased survivin expression correlated with decreased survival. The aim of the study was to investigate whether survivin gene polymorphism associates with benign and malignant brain tumors and whether it affects survivin serum levels. Patients and Methods: Survivin polymorphism -31C>G was genotyped in 82 patients with brain tumors and 65 healthy controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and survivin levels were evaluated by enzyme-linked immuno sorbent assay (ELISA) in patients and controls. Results: Serum survivin levels in patients with malignant tumors were higher than patients with benign tumors (p<0.001). Survivin levels in patients with malignant glial tumors and the frequency of the GG genotype were higher than in patients with benign tumors (p=0.04) and controls (p=0.05). The prevelance of the survivin gene promoter polymorphism -31C>G did not differ between patients and controls. Conclusion: Survivin promoter -31C>G gene polymorphism seems to be associated with serum survivin levels in brain tumors of different grades and histologies.

Expression of miRNA-21, miRNA-107, miRNA-137 and miRNA-29b in meningioma

OBJECTIVEnMeningiomas are among the most common intracranial tumors, accounting for 30% of all tumors of the central nervous system. Recent studies analyzing microRNA (miRNA) profiles and functions in cancer have provided valuable information about the molecular pathogenesis of several tumor types, including glioblastoma multiforme (GBM), hepatocellular carcinoma, and breast, lung, colon, and prostate cancer. miRNAs are a family of small, endogenous, noncoding RNAs of 18-25 nucleotides. In this study, we carried out a genome-wide array screen comparing miRNA-21, miRNA-107, miRNA-137 and miRNA-29b expression in meningiomas.nnnPATIENTS AND METHODSnA total of 50 meningioma patients (16 men and 34 women) aged between 32 and 80 years were included. The study was conducted at Istanbul Research and Training Hospital Neurosurgery Clinic.nnnRESULTSnOur results have shown a significant increase in miRNA-21 expression with increasing histopathologic grade, while there was a significant reduction in miRNA-107 expression with the increasing histopathological grade. miRNA-137 and miRNA-29b expression did not differ significantly according to histopathologic grade.nnnCONCLUSIONnThe subject of our study, i.e. the association between miRNA expression and meningioma, is continuously gaining more importance in the wider context of the recent developments in genetic treatments.

Rapidly Progressing Sellar Chondromyxoid Fibroma: A Case Report and Review of the Literature

Chondromyxoid fibroma (CMF) is a rarely seen benign cartilaginous tumor, and cranial vault involvement is infrequent. These tumors show slow progression and have a low recurrence rate if total surgical excision is achieved. In this article, a case of rapidly progressing sellar CMF with its clinical, neuroradiologic, and pathologic features is reported.