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Biomedical subjects

Hakan Caner

Publications and source records attributed to Hakan Caner.

At least 19 recordsLinked to original sources

Unusual dumbbell tumours of the mediastinum and thoracic spine.

Due to a lack of large clinical series in the literature of chondrosarcomas and hydatid disease presenting as mediastinal dumbbell tumours, clinicians have limited experience on this topic. We present three unusual cases of dumbbell tumour involving the spinal canal; two patients had chondrosarcoma originating from Th8-Th9 and Th10-Th12; one patient had a hydatid cyst at Th5-Th6. We performed a single-stage combined thoracic-neurosurgical approach in two patients, and a double-staged approach in one patient. During the intraspinal dissection, an operating microscope was used under electrophysiological monitoring. Spinal canal reconstruction was not required for any of the cases. Preoperative knowledge of neuroforaminal extension and the relations between the tumour and adjacent neural-vascular structures is essential to prevent spinal cord damage and plan the surgical approach. In chondrosarcomas, prognosis depends on patient age, histological grade, extent of surgery and response to radiotherapy and/or chemotherapy. In this article, the diagnostic and surgical difficulties of these unusual tumours and current treatment modalities are discussed with a review of the relevant literature.

Adult↗

Augmentation of a loosened sacral pedicle screw with percutaneous polymethylmethacrylate injection.

STUDY DESIGN: Case report describing augmentation of a loosened sacral screw with percutaneous injection of polymethylmethacrylate. OBJECTIVE: To highlight the advantages of percutaneous injection of polymethylmethacrylate in treatment of loosened pedicle screws. SETTING: Turkey. SUMMARY OF BACKGROUND DATA: Lumbosacral instrumentation with pedicle screws is a commonly used procedure for correcting deformity and stabilizing the spine until bony fusion occurs. Loosening of the screws is a complication of this procedure and is seen more frequently in multilevel instrumentation, particularly in those instrumentations using sacral screws. METHOD: We present the case of a woman who had had L3-L4-L5-S1 instrumentation with pedicle screws who developed severe low back pain radiating to the left hip 2 months after the operation. Radiologic and clinical examination revealed that the left pedicle screw of the sacrum had loosened, and revision surgery was planned. The left sacral screw was augmented with percutaneous injection of polymethylmethacrylate. RESULTS: The patient was free of pain after the operation. CONCLUSIONS: We suggest that percutaneous polymethylmethacrylate injection around a loosened screw may be an alternative to major open revision surgery in cases of sacral screw failure in multisegmental instrumentation.

Bone Screws↗

Atypical traumatic craniocervical junction focal spinal subdural hematoma.

Spinal subdural hematoma (SSDH) is a rare entity and post-traumatic cervical SSDH is very rare. Review of the literature revealed 8 reported cases of traumatic SSDH and only 2 were cervical. The exact mechanism and pathogenesis of SSDHs are unclear. There are still controversies about the source of bleeding and mechanisms of formation of a hematoma. Here we report a case of a unique traumatic craniocervical junction focal subdural hematoma in an 8-year-old boy and discuss the possible mechanisms of SSDHs in trauma cases.

Cervical Vertebrae↗

Systemic administration of phosphodiesterase V inhibitor, sildenafil citrate, for attenuation of cerebral vasospasm after experimental subarachnoid hemorrhage.

OBJECTIVE: One of the phosphodiesterase isoenzymes, Type V (PDE V), specifically hydrolyzes cyclic guanosine monophosphate to cause vasoconstriction. This study analyses the effect of PDE V inhibition with sildenafil citrate (SC) on cerebral vasospasm and its effect on apoptotic changes of the vascular endothelium. METHODS: Twenty-four rabbits were divided into four groups. The first group was composed of sham-surgery animals. The second group was the subarachnoid hemorrhage (SAH) group, in which cerebral vasospasm was induced. In the third group, sham-surgery rabbits were treated with SC. In the fourth group, animals were treated with SC after SAH. SC was administered for 48 hours, 0.7 mg/kg, three times per day in Groups 3 and 4. Basilar artery lumen circumferences were measured in all groups by computerized image analysis. The terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) method was used to evaluate the rate of apoptosis between SAH and SC-treated SAH groups. Results were compared by analysis of variance and paired t tests, and P values less than 0.05 were considered significant. RESULTS: Basilar artery circumferences between groups were significantly different (P < 0.001). SC (0.7 mg/kg, three times per d) significantly dilated the basilar arteries in both the sham-surgery group (2370 +/- 233 microm; P = 0.039) and the SAH group (2142 +/- 195 microm; P = 0.006) after 48 hours of treatment. The TUNEL method for apoptosis revealed that actual numbers of the apoptotic endothelial cells per cross section after SAH in the control (no treatment) (73 +/- 2) and SC-treated (0.7 mg/kg) groups(76 +/- 3) were not significantly different (P > 0.05). CONCLUSION: The vasodilatory effect of SC was observed to be significant on normal cerebral vessels and after SAH-induced vasospasm. SC did not prevent apoptosis of the endothelium in our study, which suggests that prevention of apoptosis is not necessary in the treatment of cerebral vasospasm.

3',5'-Cyclic-GMP Phosphodiesterases↗

Chromosome 1p36 and 22qter deletions in paraffin block sections of intracranial meningiomas.

Meningiomas are the most frequent benign tumors of the intracranial cavity. The classification and underlying pathogenetic mechanisms have been reported to be investigated by both pathological and genetic methods. In this study, we aimed to detect 1p36 and 22qter deletions by fluorescence in situ hybridization (FISH) in archival materials of 50 intracranial meningioma patients. The clinical material consisted of paraffin-embedded tissue sections from 50 patients who were surgically treated and had histopathologic diagnosis of an intracranial meningioma. We observed 1p36 deletion in 23/50 (46%) and 22qter deletion in 33/50 (66%) patients. In addition, we observed 22qter deletion in 26/36 (72.2%) patients with meningothelial meningioma. This finding implies that 22qter deletion might play an important role in the pathogenesis of meningothelial meningioma. On the other hand, no alterations were documented in the frequency of these chromosomal alterations according to the grade of meningiomas, suggesting that malignant progression of these tumors depends on other, more relevant, genetic changes.

Adult↗

Can E-selectin be a reliable marker of inflammation in lumbar disc disease?

The cause of sciatica and low back pain associating with lumbar disc herniation has not been clearly identified until now. Inflammation has been shown to occur via immunohistochemical and biochemical methods in herniated disc tissues. The important prognostic role of E-selectin has recently been substantiated by other studies in early rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA). The important role of adhesion molecules in the initiation and progression of the inflammatory response is well known for infectious diseases and autoimmune disorders. In our study, we aimed to show the role of E-selectin as an inflammatory marker and the correlation of inflammation with straight-leg raise (SLR) test findings and subtype of disc herniation. We found that the cases with positive SLR test had higher rates of immunostaining with E-selectin. This led us to think that E-selectin might play an important role in the activity status of the disease, meaning patients with more limited movement capacity might benefit from E-selectin antagonist therapy. Among the many studies performed to identify the relationship between the inflammation markers and activity of lumbar disc herniation, this is the first investigation held with E-selectin.

Adult↗

Nocardial epidural abscess of the thoracic spinal cord and review of the literature.

Nocardia is a potential cause of opportunistic infection in organ-transplant recipients. We report an epidural abscess causing acute paraparesis in a patient with a rejected renal transplant and chronic liver disease. Early drainage and treatment with imipenem and trimethoprim-sulfamethoxasole improved the patient's neurologic status.

Anti-Bacterial Agents↗

An unusual case of ruptured distal anterior cerebral artery aneurysm associated with brucellosis.

Reports have noted aneurysmal dilatation of arteries in association with brucellosis, but involvement of intracranial vessels has not been documented to date. Sixty-one year old female patient who had been diagnosed with brucellosis 14 months earlier presented with symptoms of subarachnoid hemorrhage (SAH). Due to deterioration of the patient's clinical condition in spite of a two-drug antibiotic regimen, she was treated surgically and made a full recovery. It is important to identify this association promptly, as there are clinical implications for optimal management. The article also discusses the timing and duration of antibiotic therapy, indications for and considerations regarding surgery, and the use of other treatment modalities.

Aneurysm, Ruptured↗

Kyphoplasty: 2 years of experience in a neurosurgery department.

BACKGROUND: Kyphoplasty is a new technique to treat collapsed vertebral body (VB) fractures. The technique is very effective for achieving rapid pain relief, restoring bone height,and consequent vertebral realignment,and thus stabilization of the vertebra. METHODS: We reviewed 57 patients with vertebral compression fractures. All patients were neurologically intact and presented with severe low back pain or localized pain over the thoracolumbar region. Indications for kyphoplasty were osteoporotic and traumatic compression fractures, osteolytic tumor metastases, and aggressive hemangiomas without spinal canal compression. RESULTS: In 57 patients, 77 levels were treated. Follow-up was 6.5 months. Patients were evaluated with a visual analog scale (VAS) preoperatively and postoperatively. The mean preoperative VAS score was 91.08 for pain, whereas the mean postoperative VAS score was 11.22. Percentage of mean pain relief was 87.9% during the first 6 months of follow-up. We achieved a 43.6% improvement in the height of the compressed VB and 6.3 degrees of improvement in the kyphotic angle. No serious complications occurred. Mean hospital stay was 24 hours. CONCLUSIONS: Kyphoplasty carries significantly less morbidity than vertebroplasty or open surgery. Risk for embolization is low. Normal kyphotic angle can be restored or improved by this technique. In the hands of experienced surgeons, kyphoplasty is a safe and a minimally invasive technique for patients with neoplastic, traumatic, or osteoporotic lesions of the vertebra or sacrum.

Aged↗

The relation between serum levels of osteoprotegerin and postoperative epidural fibrosis in patients who underwent surgery for lumbar disc herniation.

OBJECTIVES: Epidural fibrosis (EF) is a part of the normal physiological tissue response to laminectomy and it is an important cause of failed back surgery syndrome (FBSS). Osteoprotegerin (OPG) is a soluble member of the tumor necrosis factor receptor family, and is expressed in high concentrations by a variety of tissues and cell types. The objective of this study was to evaluate the relationship between serum OPG levels, and the existence of postoperative EF in patients with lumbar disc herniation. It has been suggested that cytokines and growth factors, which play a role in the wound healing, may enhance the expression of OPG. METHODS: Forty women who underwent surgery for lumbar disc herniation were included in this study. Postoperative MRI was performed to assess EF in all patients. RESULTS: The serum OPG levels of subjects with postoperative EF were significantly higher than those of subjects without postoperative EF (4.72 +/- 0.27 versus 3.25 +/-0.41 pmol/l; p=0.005) DISCUSSION: Although the role of OPG in the development of EF is poorly understood, our results suggest that elevated levels of serum OPG are associated with and may play a role in the pathogenesis of fibrotic process.

Absorptiometry, Photon↗

Effect of melatonin on cerebral vasospasm following experimental subarachnoid hemorrhage.

OBJECT: The current study was undertaken to determine whether melatonin therapy reverses vasospasm and prevents apoptosis by inhibiting lipid peroxidation in an experimental subarachnoid hemorrhage (SAH) model. MATERIALS AND METHODS: The rabbits were divided into four groups as follows: Group 1, SAH + melatonin (5 mg/kg/i.p. BID) simultaneously with SAH (n = 6); Group 2, SAH + melatonin (5 mg/kg/i.p. BID) treated 2 hours after SAH (n = 6); Group 3, control group (n = 4); Group 4, SAH only (n = 6). Light microscopic examinations of the basilar arteries were performed to demonstrate the pathophysiological changes of the arterial wall with hematoxylin- eosin. Apoptosis: Immunohistology using the ApopTag Peroxidase In Situ Apoptosis Detection Kit was used to demonstrate apoptosis in a cross section of basilary arteries. Apoptotic index was calculated as the number of the immunoreactive nuclei per total number of endothelial cells, and expressed as a percentage. RESULTS: The results of measurements of diameters of the vessels between groups were significantly different (p = 0.028). While basilar arteries of the SAH only group showed 57% constriction, Groups 1 and 2 were calculated as 33 and 26% constriction, respectively, compared with the control group (p < 0.05). And also Groups 1 and 2 showed significant protection of apoptosis compared with Group 4. The difference between the four groups was tested by Kruskal-Wallis test and the significance between the two groups was tested by Mann- Whitney U-test. CONCLUSION: Melatonin with its strong antioxidant effect can prevent SAH-induced vasospasm and apoptosis of endothelial cells of vessels.

Animals↗

Analysis and prevalence of inflammatory cells in subtypes of lumbar disc herniations under cyclooxygenase-2 inhibitor therapy.

OBJECTIVE: The aim of the present study was to analyse inflammatory cells in lumbar disc tissue under cyclooxygenase-2 (COX-2) inhibitor therapy, to detect their prevalence in different subtypes of lumbar disc herniations and to assess the influence of inflammatory reactions in herniated disc tissue on postoperative outcome. METHODS: In this prospective study, intervertebral disc specimens were obtained from 50 patients. All the patients were given COX-2 inhibitor therapy (Rofecoxib) 25 mg/day for 10 days before surgery. The herniated disc specimens were routinely fixed in a 10% buffered formaline solution and paraffin-embedded; 5 microm thin sections were stained with monoclonal antibodies CD-68 for macrophages, CD-45 RO for T cells and CD-20 for B cells. The specimens were microscopically examined and classified by two independent examiners in a blinded manner. RESULTS: CD-68 macrophages were evident in herniated lumbar disc tissue in 40% of the cases, but abundant inflammation was observed in only 18% of the cases. Macrophages were significantly common in sequesters with a prevalence of 80%, and no macrophages were observed in the protrusions. We obtained the best outcome scores in the patients with a sequestrated lumbar disc herniation. CONCLUSION: Although most of the specimens from all the patients showed no significant inflammatory reaction, maybe due to COX-2 inhibitor therapy, they all needed surgery with no relief of the symptoms despite conservative therapy. Nerve root compression still seems to be the leading pathomechanism.

Adult↗

Mexiletine treatment-induced inhibition of caspase-3 activation and improvement of behavioral recovery after spinal cord injury.

OBJECT: It has been demonstrated in several experimental studies that apoptosis contributes to cellular damage after spinal cord injury (SCI). During apoptosis dying cells secrete additional mediators of apoptosis such as cytokines and free radicals which have additional toxic effects and exacerbate neuronal death. The aim of this laboratory study was to investigate the effects of mexiletine on caspase-3 activation and functional recovery and compare its post-SCI effectiveness with methylprednisolone. METHODS: The rats were divided into five groups. Animals in the trauma group underwent traumatic interventions after laminectomy. Spinal cord contusion injury was produced using the weight-drop method. Animals in treatment groups received a single dose of methylprednisolone sodium succinate (Group C), single dose of mexiletine (Group D), or vehicle solution (saline; Group E) intraperitoneally immediately after injury. Hind-limb functions were assessed using the inclined plane technique and caspase-3 activity in tissue samples was measured 24 hours after SCI. Traumatic injury was found to increase tissue caspase-3 activity. In both treatment groups the drug prevented an increase in caspase-3 activity. Mexiletine treatment improved early behavioral recovery after SCI. CONCLUSIONS: The results obtained in this study demonstrated that mexiletine treatment inhibits caspase-3 activation and preserve/restore better neuronal function compared with methylprednisolone after experimental SCI.

Animals↗

The role of closed-suction drainage in preventing epidural fibrosis and its correlation with a new grading system of epidural fibrosis on the basis of MRI.

In this study we aimed to evaluate the role of closed-suction drainage on the extent of epidural fibrosis (EF) after lumbar disc surgery and to define a new grading system of epidural fibrosis in these patients, based on magnetic resonance imaging. Seventy-nine patients (34 women, 45 men) with a unilateral, single-level lumbar disc herniation were included in this study. Forty-one patients in whom closed-suction drainage was implanted were compared with 38 patients in whom the drain was not implanted. We have used a new grading system for the extent of epidural fibrosis, on the basis of follow-up magnetic resonance imaging findings. Pain intensity was evaluated by visual analog scale (VAS), and the patients' function and working ability were measured according to the Prolo functional-economic scale. We conclude that, in patients operated on for unilateral, single-level lumbar disc hernias, implantation of closed-suction drainage into the operation site results in less formation of EF radiologically and yields better clinical outcome.

Adult↗

Primary primitive neuroectodermal tumor within the spinal epidural space: report of a case and review of the literature.

Primary intraspinal primitive neuroectodermal tumors (PNETs) are rare tumors and a have poor prognosis. In reviews of the literature, it is seen that primary intraspinal PNETs may arise at all levels of the spine and may be intramedullary, intradural-extramedullary, or epidural. Spinal epidural location of PNET is extremely rare and out of 22 cases of primary spinal PNETs reported to date, only two were epidural. Tumors within the epidural space of the spinal canal are most often metastatic neoplasms from different primary sites. Here we report a case of primary extradural PNET located in the thoracic spine in a 16-year-old boy and review the relevant literature.

Adolescent↗

Hemispheric cerebrovascular venous thrombosis due to closed head injury.

CASE REPORT: We present the case of an 8-month-old infant who was admitted to our Neurosurgery Department with venous infarction related to sagittal sinus thrombosis. The infarction was radiologically detected 5 days after the baby had undergone surgery for acute subdural hematoma due to a closed head injury. RESULTS AND CONCLUSIONS: Cerebrovascular venous thrombosis is a rare clinical entity that has multiple causes and variable presenting symptoms. There is no consensus on overall strategy concerning surgical, radiosurgical, or medical therapy (anti-coagulation, thrombolytic, and anti-edema treatment), and exactly how, when, or in which cases these should be applied. The treatment planning should be based on clinical findings, and should be modified according to the clinical course. In this case, the clinical and radiological findings regressed with symptomatic treatment alone.

Brain Edema↗