Ilhan Yilmaz

Rational Roots of Sympathetic Overactivity by Neurogenic Pulmonary Edema Modeling Arising from Sympathyco-Vagal Imbalance in Subarachnoid Hemorrhage: An Experimental Study.

BACKGROUND Autonomous innervations of the lungs are maintained by cervical sympathetic and vagal nerves. Sympathetic overactivity-induced neurogenic pulmonary edema (NPE) is known as a serious complication of subarachnoid hemorrhage, but the rational neuronal mechanism of that overactivity has not yet been clarified fully. The aim of this study was to examine whether there is a relationship between vagal nerve ischemia related sympathetic overactivity and neurogenic pulmonary edema in subarachnoid hemorrhage. METHODS This study was conducted on 27 rabbits. A control group was formed of 5 animals, a sham group of 7 to which saline was administered, and a study group of 15 animals that were injected with homologous arterial blood into the cisterna magna. Electrocardiography and respiratory rhythm parameters were monitored for 3 weeks and the animals were then decapitated. Statistical analysis was made of the numbers of degenerated axons in the pulmonary branches of the vagal nerves, the neuron density of stellate ganglions and the vasospasm index of the pulmonary arteries. RESULTS In the control group, the normal respiration rate was 34 ± 6 bpm, total axon number was 1600 ± 270/mm(2), degenerated axon number was 10 ± 3/mm(2), and vasospasm index was 1.34 ± 0.25. The sham group values were 30 ± 3 bpm, 163 ± 47/mm(2), and 1.95 ± 0.45 and the study group values were 45 ± 8 bpm, 530 ± 92/mm(2), and 2.76 ± 0.83. The mean stellate ganglion neuron density was evaluated as 8.112 ± 1.230/mm(3) in all animals, as 7.420 ± 4.10/mm(3) in animals with slight NPE, and as 12.512 ± 1.236/mm(3) in animals that developed severe NPE. CONCLUSION High neuron density of stellate ganglion may have important roots in sympathetic overactivity-related NPE development in subarachnoid hemorrhage.

Adding Expansile Duraplasty to Posterior Fossa Decompression May Restore Cervical Range of Motion in Grade 3 Chiari Malformation Type 1 Patients

BACKGROUND Few studies have assessed the effect of Chiari malformation type 1 (CM-1) surgical decompression on cervical lordosis and range of motion (ROM). We aimed to assess the effect of expansile duraplasty on postoperative cervical mobility and spinal stability. MATERIALS AND METHODS This was a single-center retrospective review of prospectively collected data. Patients were included if they underwent surgical treatment for symptomatic CM-1 between the years 1999 and 2009. Cervical ROM and lordosis were assessed before and after surgery in all patients. Collected data also included clinical improvement, as well as surgical complications after the procedure. Patients were divided into 2 groups. The first group underwent a posterior fossa bony decompression alone, while the second group additionally received an expansile duraplasty. Patients were further subdivided into 3 subgroups on the basis of the severity of tonsillar herniation. RESULTS A total of 76 patients fit our selection criteria. Fifty-five patients belonged to the duraplasty group. Twenty-one patients underwent bony decompression alone. The 2 groups were statistically demographically and clinically similar. There was no difference in clinical outcome or in ROM and cervical lordosis between the groups except for patients with severe tonsillar herniation (CM-I grade 3). These patients had a statistically significant improvement in their postoperative cervical motility without compromising their spinal stability. CONCLUSION Adding an expansile duraplasty to craniovertebral decompression in CM-1 patients with severe tonsillar herniation may restore cervical ROM while preserving stability and alignment. This may relieve postoperative pain and improve clinical prognosis.

Uncovering of The Forgotten Effect of Superior Cervical Ganglia On Pupil Diameter Determination in Subarachnoid Hemorrhage: Experimental Study.

AIM To investigate the relationship between neuron density of the superior cervical sympathetic ganglia and pupil diameter in subarachnoid hemorrhage. MATERIAL AND METHODS This study was conducted on 22 rabbits; 5 for the baseline control group, 5 for the SHAM group and 12 for the study group. Pupil diameters were measured via sunlight and ocular tomography on day 1 as the control values. Pupil diameters were re-measured after injecting 0.5 cc saline to the SHAM group, and autologous arterial blood into the cisterna magna of the study group. After 3 weeks, the brain, superior cervical sympathetic ganglia and ciliary ganglia were extracted with peripheral tissues bilaterally and examined histopathologically. Pupil diameters were compared with neuron densities of the sympathetic ganglia and ciliary ganglia which were examined using stereological methods. RESULTS Baseline values were; normal pupil diameter 7.180±620 ?m and mean neuron density of the superior cervical sympathetic ganglia 6.321±510/mm3, degenerated neuron density of ciliary ganglia was 5±2/mm3 after histopathological examination in the control group. These values were measured as 6.850±578 ?m, 5.950±340/mm3 and 123±39/mm3 in the SHAM group and 9.910±840 ?m, 7.950±764/mm3 and 650±98/mm3 in the study group. A linear relationship was determined between neuron density of the superior cervical sympathetic ganglia and pupil diameters (p < 0.005). Degenerated ciliary ganglia neuron density had an inverse effect on pupil diameters in all groups (p < 0.0001). CONCLUSION Highly degenerated neuron density of the ciliary ganglion is not responsible for pupil dilatation owing to parasympathetic pupilloconstrictor palsy, but high neuron density of the pupillodilatatory superior cervical sympathetic ganglia should be considered an important factor for pupil dilatation.

Impact of sorafenib on epidural fibrosis: An immunohistochemical study

AIM To determine if sorafenib, an antineoplastic agent, could prevent the development of spinal epidural fibrosis (EF). METHODS The study used CD105 and osteopontin antibodies in an immunohistochemical approach to quantify EF that occurred as a consequence of laminectomy in rats. Wistar albino rats (n = 16) were divided into two groups: control (L1-2 level laminectomy only) and sorafenib treatment (L1-2 level laminectomy + topical sorafenib). The animals were euthanatized after 6 wk, and the EF tissues were examined for histopathological changes after immunohistochemical staining. The EF grades were assigned to the tissues, and the treatment and control groups were compared. RESULTS The EF thickness, inflammatory cell density, and arachnoid adherences determined by light microscopy were significantly higher in the control group compared to the sorafenib-treated group. Based on fibrosis scores, the extent of EF in the treatment group was significantly lower than in the controls. Immunohistochemical staining for CD105 to identify microvessels revealed that the EF grades based on vessel count were significantly lower in the treatment group. Staining for osteopontin did not show any significant differences between the groups in terms of the extent of EF. The staging of EF based on vascular counts observed after immunohistochemical staining for CD105, but not for osteopontin, was compatible with conventional staging methods. Neither toxic effects on tissues nor systemic side effects were observed with the use of sorafenib. CONCLUSION Local administration of sorafenib significantly reduced post-laminectomy EF. Decreased neovascularization in spinal tissue may be due to the sorafenib-induced inhibition of vascular endothelial growth factor.

Comparison of rigid and semi-rigid instrumentation under acute load on vertebrae treated with posterior lumbar interbody fusion/transforaminal lumbar interbody fusion procedures: An experimental study

Rigid and semi-rigid fixations are investigated several times in order to compare their biomechanical stability. Interbody fusion techniques are also preferable for maintaining the sagittal balance by protecting the disk height. In this study, the biomechanical comparison of semi-rigid and rigid fixations with posterior lumbar interbody fusion or transforaminal lumbar interbody fusion procedures is conducted under trauma. There were four different test groups to analyze the effect of acute load on treated ovine vertebrae. First and second groups were fixed with polyetheretherketone rods and transforaminal lumbar interbody fusion and posterior lumbar interbody fusion cages, respectively. Third and fourth groups were fixed with titanium rods and posterior lumbar interbody fusion and transforaminal lumbar interbody fusion cages, respectively. The drop tests were conducted with 7 kg weight. There were six samples in each group so the drop test repeated 24 times in total. The test samples were photographed and X-rayed (laterally and anteroposteriorly) before and after drop test. Two fractures were observed on group 1. Conversely, there were no fractures observed for group 2. There were no anterior element fractures for both groups 1 and 2. However, one fracture seen on group 3 was anterior element fracture, whereas the other three were posterior element fractures. All three fractures were anterior element fractures for group 4. Treated vertebrae with polyetheretherketone rods and posterior lumbar interbody fusion cages showed the best durability to the drop tests among the groups. Semi-rigid fixation gave better results than rigid fixation according to failed segments. Posterior lumbar interbody fusion cages seem to be better option for semi-rigid fixation, however mentioned surgical disadvantages must be considered.

Factors That Affect Postoperative Hydrocephalus Development In Aneurysmal Subarachnoid Hemorrhage: Clinical Study.

AIM Factors affecting the development of postoperative hydrocephalus patients who underwent surgery after aneurysmal subarachnoid hemorrhage were retrospectively assessed. MATERIAL AND METHODS 201 cases, who underwent aneurysm surgery in our clinic after subarachnoid hemorrhage between 2008 and 2013, were retrospectively assessed. Twenty-one cases with hydrocephalus development were retrospectively examined according to their age, gender, history (hypertension, alcohol, and smoking), blood type, the number and size of aneurysms, aneurysm localization, the presence of ventricular hemorrhage, baseline-final neurological diagnosis, Fisher grading system, history of vasospasm and meningitis. The initial neurological course and Hunt-Hess, and also final neurological course of the patients were evaluated according to World Federation of Neurosurgical Societies (WFNS) Grading Scale. RESULTS Age, history of hypertension, aneurysm localization, Hunt-Hess grading, vasospasm, meningitis and Glasgow Outcome Scale (GOS) are determinative factors in hydrocephalus development due to subarachnoid hemorrhage. It was detected that gender, alcohol and tobacco use, blood group, the size and the number of aneurysm, the presence of intraventricular hemorrhage and Fisher grading were not the determinative factors in the patients. CONCLUSION In patients who underwent surgery for subarachnoid hemorrhage, risk factors for postoperative hydrocephalus should be determined and the patients with these risk factors should be closely monitored.