Ibrahim Erkutlu

Three-layer reconstruction with fascia lata and vascularized pericranium for anterior skull base defects

SummaryBackground. We report an assessment of the efficiacy of a triple layer graft composed of fascia lata and vascularized pericranium for anterior skull base reconstruction. This technique is based on the concept that vascularized tissue over a free flap may promote vascularization and rapid wound healing. Method. A large fascial graft is prepared from the fascia lata and divided in two pieces and trimmed to a size larger than the bone and dural defect. Vascularized pericranium is harvested after bicoronal incision and elevating the bifrontal scalp flap down to the supraorbital rims. First is dural repair, which is performed with fascia lata placed between the brain and remaining dura. Second, fascia lata is placed over the skull base defect and secured with mini titanium screws over the cranial surface of the orbital ridges. Third, vascularized pericranium is laid between the two layers of fascia lata. Findings. We studied 17 patients of whom 2 had malignancy, 6 had olfactory groove meningioma, 6 had skull base fracture and rhinorrhea, 1 case had orbital meningioma, 1 had invasive pituitary adenoma and 1 had basal encephalocele. The transbasal approach was used as a single procedure in 13 cases. The extended transbasal approach combined with a transfacial approach was used in 3 cases and with a pterional approach in 1 case. In each patient, reconstruction of the cranial base was performed with triple layer graft of fascia lata and vascularized pericranium. The patients were followed-up 2 months to 5 years. None of the patients experienced postoperative cerebrospinal fluid leakage, meningitis, abscess, brain herniation and tension pneumocephalus. Interpretation. Fascia lata with vascularized pericranium is highly reliable, tensile and well suited for reconstruction of the anterior skull base.

The Effects of Exogenous Melatonin on Peripheral Nerve Regeneration and Collagen Formation in Rats

BACKGROUND Peripheral nerve damage that requires surgical repair does not result in complete recovery because of collagen scar formation, ischemia, free oxygen radical damage, and other factors. To date, the best treatment method has not yet been determined. In this study, we designed an experimental peripheral nerve injury model, and researched the possible effects of melatonin hormone, based on evidence of its strong antioxidant and cell-protective effects via mimicking the effects of calcium channel blockers. MATERIALS AND METHODS We randomized 24 healthy female albino rats into three groups: the pinealectomy group, melatonin group, and control group. In the pinealectomy group, craniotomy, pinealectomy, sciatic nerve transection, and coaptation were performed, and 0.9% NaCl was injected intraperitoneally. In the melatonin group, craniotomy (without pinealectomy), sciatic nerve dissection, and coaptation were performed, and melatonin was injected intraperitoneally, instead of NaCl. In the control group, craniotomy (without pinealectomy), sciatic nerve dissection and coaptation, and intraperitoneal NaCl injection were performed. In each group, nerve recovery was evaluated histologically, functionally, and electrophysiologically. Functional and electrophysiologic evaluations were conducted before surgery and at 4 and 12 wk. RESULTS At 4 wk, no significant difference was observed between the groups. However, at 12 wk, significant electrophysiologic and functional improvement was observed only in the melatonin group. CONCLUSIONS Melatonin seems to have a beneficial effect on nerve recovery. However, this effect is not effective at physiologic doses. Future comparative studies with melatonin versus other nerve-regenerating agents are necessary to determine the clinical utility of melatonin hormone.

A New Technique for Closure of Large Meningomyelocele Defects

Background:Although small meningomyeloceles may be amenable to direct closure by undermining of the surrounding skin, the closure of large meningomyelocele defects is a challenging reconstructive problem. Purpose:Here, we present a new surgical procedure for the closure of large meningomyelocele defects. Material and Methods:In this procedure, after neurosurgical repair and closure of the placode, the defect is surgically converted to a triangle in shape. Then, the triangular defect is closed by transposition of 2 skin flaps designed in an unequal z-plasty manner. Over 3 years, this new technique, namely Mutaf triangular closure procedure, was used for the closure of large meningomyelocele defects in 5 patients, aged between 2 days to 6 weeks. The defect size was 10.4 × 7.5 cm on average. Results:In all patients, a tension-free 1-stage closure was obtained. Except one with a minimal hematoma, all patients healed with no complication. There was no patient with late breakdown of the wound during 2 years of mean follow-up. Conclusions:Besides the 2 major advantages of short operative time and minimal blood loss, our technique provides a well-vascularized soft tissue padding over the neural tissues, and no suture line overlies the cord closure. With these advantages, this new technique seems to be a useful and safe solution for closure of large meningomyelocele defects.

Pretreatment with Dexmedetomidine or Thiopental Decreases Myoclonus after Etomidate: A Randomized, Double-Blind Controlled Trial

BACKGROUND Myoclonic movements are common problems during induction of anesthesia with etomidate. The aim of this study was to compare the effect of pretreatment with dexmedetomidine (0.5 microg/kg) and thiopental (1 mg/kg) on the incidence of etomidate-induced myoclonus and postoperative pain. MATERIALS AND METHODS A prospective double-blind study was conducted at a university hospital. Ninety patients (ASA physical status I-II) were randomly assigned to one of three groups: patients were pretreated with either dexmedetomidine (0.5 microg/kg), thiopental (1 mg/kg), or saline before induction of anesthesia with etomidate. One minute after the injection of study drugs, etomidate, 0.3 mg/kg was given. Myoclonus was assessed on a scale of 0 to 3. Recovery time, postoperative pain score, and hemodynamic variables were recorded during the intraoperative and postoperative period. Headache, nausea, vomiting, and coughing were noted during the study. RESULTS The incidence and the intensity of myoclonus was significantly lower in the dexmedetomidine and thiopental groups (34%, 36%) than in the control group (64%) (P<0.05). The postoperative pain score at 30 min in the thiopental group was significantly higher than in the dexmedetomidine and control groups (63%) (P<0.05). CONCLUSIONS We concluded that pretreatment with dexmedetomidine or thiopental is effective in reducing the incidence and severity of etomidate-induced myoclonic muscle movements and pretreatment with thiopental increases the postoperative pain.

Premedication With Dexmedetomidine Alone or Together With 0.5% Lidocaine for IVRA

BACKGROUND This study aimed to compare the effects of low and same dose of dexmedetomidine when added to lidocaine for intravenous regional anesthesia (IVRA) and when administered for premedication before IVRA. MATERIAL AND METHODS In this double blind study, 45 patients with ASA physical status I-II were scheduled to undergo carpal tunnel release as an outpatient procedure and were randomly divided into three groups. IVRA was performed with 40 mL of 0.5% lidocaine in the operating room. A single dose of dexmedetomidine 0.5 μg/kg and placebo (saline) solution in a total volume of 20 mL were administered intravenously to group P (n=15) and group S (n=15), respectively, before IVRA. 0.5 μg/kg of dexmedetomidine was added to lidocaine in group A (n=15) during IVRA. The onset and recovery time of sensory and motor block, intraoperative-postoperative visual analog scale (VAS) and Ramsay sedation scores (RSS), analgesic requirement, hemodynamic variables, and side effects were noted. RESULTS Significantly shortened sensory block onset and recovery time in group P and A, shortened motor block onset time in group P, and decreased intra-postoperative VAS scores and analgesic requirement in groups P and A were found. Intraoperative RSS in group P and postoperative RSS in groups P and A were higher than in group S. Intraoperative and postoperative heart rate and postoperative mean arterial blood pressure (MAP) of group P was significantly lower than groups A and group S, respectively. CONCLUSION Both addition of dexmedetomidine to lidocaine and premedication with dexmedetomidine for IVRA similarly improve quality of anesthesia and perioperative analgesia without important side effects.

Correlation between Rho-kinase pathway gene expressions and development and progression of glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the most common and the most aggressive primary malignant tumor of the brain. Prognostic factors in GBM can be sorted as age, tumor localization, tumor diameter, symptom period and type, the extent of surgery, postoperative tumor volume, and adjuvant radiotherapy and/or chemotherapy status. Besides the interactions between actin microfilaments, microtubules, and intermediate filaments, environmental factors and intracellular signals which regulate them affect the cell invasion. Rho proteins and therefore Rho-kinase activation play important role at these changes. The aim of this study is to evaluate the relationship between the Rho-kinase pathway gene expressions and prognosis in GBM. Ninety-eight patients diagnosed as GBM between 2001 and 2010 were enrolled into the study. RNA was obtained from the paraffinized tumor tissue of the patients with formalin-fixed, paraffin-embedded RNA isolation kit and the mRNA expressions of 26 genes were investigated. There was a statistically significant negative correlation between the ages at the diagnosis and survival. There was a significant relationship between the overexpression of Rho-kinase pathway-related genes LIMK1, CFL1, CFL2, and BCL2 and low expression of MAPK1 gene and the survival of the patients. These results demonstrate for the first time that there is a marked contribution of Rho-kinase pathway-related genes to the progression and survival of the GBM. The expression of these genes may be related to response of multimodal therapy or these parameters could be used to determine possible unresponsive patients before treatment.

Modified IDARAM chemotherapy regimen for primary central nervous system lymphoma: experience of three cases

Abstract The use of radiotherapy (RT) with chemotherapy has improved disease free survival and control in primary central nervous system lymphoma (PCNSL). We have encountered three patients with histologically documented central nervous system lymphoma. In all patients pathological diagnosis was B-cell lymphoma. We modified IDARAM regimen to R-IDARAM to enhance and optimize chemotherapeutic components for the treatment of PCNSL. We made three changes: (i) we added rituximab 375 mg/m2 day 1; (ii) increased dose of MTX from 2 to 3 g/m2; and (iii) administered two additional courses of R-IDARAM after cranial RT. Following complete staging after course 2, radiotherapy was applied at a dosage of 3600–4140 cGy in conventional schedule (180 or 200 cGy per day) to whole brain (with 3600 cGy to eyes in one case because of eye involvement) and then 2 additional courses of R-IDARAM (totally four courses) chemotherapy regimen were applied. Complete remission (CR) was achieved after first two cycles of R-IDARAM in patient 1 and 3 and after four cycles in patient 2. Currently, three patients have been alive for 29, 10, 15 months respectively. Currently there is no standard treatment modality for PCNSL. Increased dosage of MTX, adding rituximab and consolidation of the IDARAM to R-IDARAM regimen may improve disease control and outcome in PCNSL patients.

PRIMARY SPINAL EPIDURAL EXTRAOSSEOUS EWING'S SARCOMA MIMICKING A SPINAL ABSCESS

Ewings sarcoma is one of the most common malignant tumors of the skeletal system in children and young adults. It most frequently stems from the long bones of the extremities. However, though uncommon, extraosseous localization can be seen. Epidural extraosseous presentations are extremely rare. In this case, the authors report on the long-term follow-up of a patient with this well-demonstrated, but uncommon localization, and the initial unique presentation of the patient, which clinically and radiologically mimicked a cervical abscess.

Efficiacy of Methylprednisolone in Acute Experimental Cauda Equina Injury

Summary. In this experimental study the efficiacy of methylprednisolone was investigated by neurophysiological and histopathological evaluation in a rabbit cauda equina model where injury was produced with an aneurysm clip (closed pressure 192 gr). High dose methylprednisolone (kg/30 mg) was administered by intravenous infusion in the 8th, 16th and 24th hours after injury followed by infusion of the same dosage every 6 hours for 24 hours. Nerve conduction velocity was measured before and early after trauma and 3 weeks after injury. Both neurophysiological and histopathological investigations demonstrated the neuroprotective effectiveness of methylprednisolone if it was given in the 8th hour after trauma. Although recovery was observed its efficiacy was less pronounced when it was given in the 16th and 24th hours.

TOTAL BRAIN TISSUE SIALIC ACID LEVELS DUE TO GLUTATHIONE EFFECT IN EXPERIMENTAL EPILEPSY

Epilepsy can be described as a group of neurological disorders, characterized by recurrent episodes of convulsive seizures, loss of consciousness, sensory disturbances, abnormal behavior, or all of these. Altered glutathione metabolism in association with increased oxidative stress has been implicated in the pathogenesis of many diseases such as seizures. It is therefore reasonable to propose that sialic acid levels can be affected by this pathological state or, alternately, by seizures. The present study showed that the sialic acid levels were significantly different between the experimental groups as well as in the subgroup analysis. The results suggest that glutathione may have a neuroprotective effect by decreasing sialic acid levels in mice brain.