Intraoperative microvascular Doppler sonography in aneurysm surgery.

OBJECTIVE: The goal of this study was to evaluate the efficacy and reliability of intraoperative microvascular Doppler sonography (MDS) for the assessment of cerebral haemodynamics in aneurysm surgery. METHODS: For 40 patients (21 men, 19 women, mean age 54.0 years, range 23-73 years) who underwent surgery for the treatment of 48 intracranial aneurysms, microvascular Doppler sonography with a 20-MHz microprobe was used before and after clip application, to confirm the complete obliteration of the aneurysm. Postoperative angiography was performed to assess the complete occlusion of the aneurysm and the patency of adjacent vessels. The findings of MDS were analysed and compared with the postoperative angiography. RESULTS: A 1-mm diameter microprobe was able to insonate all vessels of the circle of Willis and their major branches and perforating arteries were reliably insonated. The aneurysm clip was repositioned on the basis of the MDS findings in 12 out of 48 patients (25%). For 9 aneurysms (18.7%) MDS exposed a relevant stenosis of an adjacent vessel induced by clip positioning that had escaped detection by visual inspection. Clip repositioning resulted in complete occlusion of the aneurysms in 7 of 9 cases (14.5%). In two cases, additional wrapping became necessary as it was not possible to achieve complete clipping. The mean duration of MDS investigations was 5.3 minutes. There were no complications of intraoperative MDS probe use. CONCLUSION: Intraoperative MDS should be used routinely in cerebral aneurysm surgery, especially for large, complicated and giant aneurysms. Intraoperative MDS is a feasible, safe, and very reliable technique in aneurysm surgery. This technique is a valuable tool, in many instances, in place of intraoperative angiography for the surgical treatment of aneurysms.

Neuronavigation in skull base tumors.

OBJECTIVE: Computer-assisted neuronavigation was used in 87 cases of skull base lesions (SBLs). Preoperative planning and intraoperative identification of anatomic landmarks is especially important in SBLs since it helps to avoid or minimize surgical morbidity and mortality. In this study, we assessed the accuracy and the clinical usefulness of a frameless system based on the optical digitizer in SBLs. PATIENTS AND METHODS: Between April 2000 and March 2003, eighty-seven patients with SBLs were operated on in our department using cranial neuronavigation. A passive-marker-based neuronavigation system was used for intraoperative image guidance. There were 56 women and 31 men. The patient's ages ranged from 4 to 76 years (average: 45.7 year). The locations of the tumors reported in this series were as follows: frontobasal, 24 cases; sellar/parasellar, 32 cases; petroclival, 16 cases; tentorial/subtemporal, 15 cases. RESULTS: The computer-calculated registration accuracy ranged between 0.3 and 1.7 mm (mean, 1.1 mm). Gross total removal of the SBLs was accomplished in 82 out of 87 patients as was confirmed on postoperative CT and MRI scans. The follow-up period ranged from 1 month to 48 months (average: 20.1 months). Overall mortality and severe morbidity (meningitis, permanent cranial nerve deficits, and cerebrospinal fluid fistulae) rates were 4.6 % and 33.3 %, respectively. CONCLUSION: The image-guided surgery is a valuable aid for safe, helpful and complete removal of SBLs of the brain where accurate localization of the lesion is critical. Although our preliminary series is not large, interactive image guidance provides a constant display of surgical instrument position during surgery and its relationship with the SBLs components, surrounding normal brain, and vascular structures, providing valuable guidance to the surgeon during an operation. Our experience with the neuronavigation suggests that image guidance is helpful in this type of lesions, providing better anatomic orientation during skull base surgery, delineating tumor margins and their relation to critical neurovascular structures.

Successful surgical excision of juvenile-type spinal arteriovenous malformation in two stages following partial embolization.

The case of a 24-year-old man with a juvenile-type spinal arteriovenous malformation is reported. Spinal angiography and magnetic resonance image revealed a juvenile (Type III) AVM at the cervical spine. This spinal malformation was successfully resected with a posterior and anterior surgical approach in two stages following partial embolization.

The surgical management of traumatic C6 - C7 spondyloptosis in a patient without neurological deficits.

An unusual case of traumatic C6 - 7 total spondyloptosis with neurologically intactness at the time of injury is reported in a 35-year-old man. The patient was treated with a single-stage combined anterior-posterior and anterior operation to restore the cervical spondyloptosis, and creation of a three-column stabilization of the spine without neurological deficits. To the best of the authors' knowledge, there is no case report of traumatic spondyloptosis of cervical spine, presenting without neurological deficits in the pre- and postoperative periods. A brief summary of the clinical presentation, the surgical technique, and a review of the relevant literature are presented.

Surgical treatment of thalamic hematomas via the contralateral transcallosal approach.

Acute management of deep-seated hematomas remains controversial. Since patients with these hematoma later tend to develop severe edema and necrosis around the lesion, when surgery is indicated it should be done as early as possible. The purpose of this study was to compare whether early surgical removal and conservative treatment of primary thalamic hematoma correlated with improved neurological outcome. Last year, 61 patients with primary thalamic hematomas were admitted to our institution. Of these, 21 underwent surgery via contralateral transcallosal approach during the ultraearly stage (within 6 hours) after the apoplectic attack, and 24 patients were treated conservatively. Another 16 patients were excluded from the study due to systemic disease, mild hematoma (<40 cc), and deep coma associated with absence of brain stem reflexes. Initial Glasgow coma scores (GCS) at admission were similar for operated and nonoperated patients (8.64 +/- 1.93 versus 9.50 +/- 2.10, P>0.05). In the operated group, two patients had good recoveries and returned to normal life (Glasgow Outcome Score, or GOS, I), four had moderate disability and needed partial care (GOS II), six had severe disability and needed nursing care (GOS III), and six had a vegetative state (GOS IV). However, in the nonoperated group, one patient had good recovery and returned to normal life (GOS I), two had moderate disability and needed partial home care (GOS II), three had severe disability and needed nursing care (GOS III), and six had a vegetative state (GOS IV). In this group, the 30-day mortality rate was 50%. Mortality was markedly lower in the operated group (14.3%) than the nonoperated group. and this difference was statistically significant (chi2=3.33, P<0.05). From this study, we believe that evacuation of primary thalamic hematoma via the contralateral transcallosal microsurgical approach may be useful for deciding on the indication and predicting the functional prognosis.

The effect of allopurinol on focal cerebral ischaemia: an experimental study in rabbits.

In this experimental study, the neuroprotective effect of the xanthine oxidase inhibitor allopurinol on focal cerebral ischaemia created by permanent middle cerebral artery occlusion (MCAO) was investigated. Using high performance liquid chromatography (HPLC), we measured hypoxanthine, xanthine, and uric acid (UA) levels in rabbit brains following focal cerebral ischaemia. Rabbits were randomly and blindly assigned into four groups of eight animals each. The control groups received 2% carboxymethylcellulose solution, while 10% allopurinol 150 mg/kg was given to the treatment group 1 h before ischaemia. Each group was subdivided into two groups which were sacrificed 4 h or 24 h after ischaemia, respectively. UA and xanthine values of the rabbits in the control groups were quite high at both times and highest after 24 h, particularly in the centre of the ischaemia. A significant decrease in UA and xanthine values was observed in rabbits that were given allopurinol (P<0.05). According to our results, it was concluded that allopurinol pretreatment protects neural tissue in the early period after arterial occlusion and prevents cerebral injury in the late period, especially in the perifocal area, possibly by preventing the formation of free radicals with xanthine oxidase inhibition.

Posterolaterally displaced type IIA odontoid fractures.

A case of type IIA odontoid fracture with posterolateral dislocation accompanied by spinal cord injury is presented. Cervical traction was employed but reduction could not be achieved with up to 8 kg of traction. The patient was treated with intraoperative reduction and C1-2 posterior transarticular screw fixation with supplemental bone-wire fusion, and rigid fixation was obtained without any complication.

Intradural lumbar disc herniation: report of two cases.

Intradural lumbar disc herniation (ILDH) is a rare pathology. The pathogenesis of ILDH is not known with certainty. Adhesions between the ventral wall of the dura and the posterior longitudinal ligament (PLL) could act as a preconditioning factor. Diagnosis of ILDH is difficult and seldom suspected preoperatively. Prompt surgery is necessary because the neurologic prognosis appears to be closely linked to preoperative duration of neurologic symptoms. Despite preoperatively significant neurological deficits, the prognosis following surgery is good. We report on two new cases of ILDH of high lumbar locations L1-2 and L2-3 with difficult differential diagnoses, and the possible pathogenic factors are discussed.

Hemilaminectomy for the removal of the spinal lesions.

OBJECTIVE: We evaluated 20 patients with spinal lesions with respect to the value of unilateral hemilaminectomy at the Department of Neurosurgery, Erciyes University, Medical Faculty, Kayseri, Turkey. The operative technique of the limited approach for spinal lesions is described. METHODS: The study is based on 20 prospective consecutive patients with spinal lesions who had unilateral hemilaminectomy. There were 12 women and eight men. Age ranged from 17 to 63 years mean (42 years) with a slight preponderance of women patients (60%). Spinal lesions were cervical in three cases, lumbar in five cases, and thoracic in 12 cases. Hemilaminectomy was performed by using a high speed drill. RESULTS: Postoperative neurological status was unchanged in six cases, improved in 11 cases, and worsened in three cases. We only observed two cases of wound infections that were not related to our surgical approach. At the follow-up evaluation, which occurred approximately 25 months after surgery none of the patients showed spinal deformity or spinal instability. CONCLUSION: The rationale of attempting unilateral approach is to avoid damage to the dorsal static structures of the vertebral column. With the precise preoperative definition of the relationship of tumor to the surface of the spinal cord by contrast enhanced MRI, unilateral approaches might be more applicable to spinal lesions except invasive extradural lesions.

Effect of EGb-761 on vasospasm in experimental subarachnoid hemorrhage.

Based on the previously suggested hypothesis that the generation of free radicals leading to lipid peroxidation is involved in the genesis of vasospasm and vasculopathy following subarachnoid hemorrhage, the therapeutic effect of EGb 761 as an antioxidant on experimental vasospasm and vasculopathy was evaluated in a double hemorrhage dog model of chronic cerebral vasospasm. For this study 14 dogs were randomly assigned to two groups, a control and a Ginkgo biloba group. The control group was only administered saline in a volume equivalent to a dose of 100 mgEGb 761/kg while the treatment group was given 100 mg EGb 761/kg. The diameter of the basilar artery decreased from 1.95 +/- 0.16 mm at day 0 to 1.11 +/- 0.07 mm at day 8 in the control group, while in the treatment group the vessel diameter decreased from 2.01 +/- 0.17 mm at day 0 to 1.72 +/- 0.16 mm at day 8. These results correspond a decrease in vessel diameter of 15.1% in the treatment group and of 43.1% in the control group (P < 0.05). Histopathological studies of the specimens obtained from basilar arteries showed that pathological signs of proliferative vasculopathy, including narrowing of the vessel lumen, corrugation of the lamina elastica and subendothelial thickening, were present in all the animals in the control group, while they could not be demonstrated in the Ginkgo biloba group. These results suggest that Ginkgo biloba may have a protective effect against subarachnoid hemorrhage-induced vasospasm and vasculopathy as a result of antioxidants.

Therapeutic effect of tirilazad mesylate (U-74006F), mannitol, and their combination on experimental ischemia.

The effect of tirilazad mesylate (U-74006F), mannitol, and their combination was investigated on focal cerebral ischemia induced by permanent middle cerebral artery (MCA) occlusion in rabbits. Rabbits were divided into four groups receiving vehicle, U-74006F, mannitol, and U-74006F plus mannitol. Hematocrit (hct), glucose, mean arterial blood pressure (MABP), pH, PCO2, and PO2 were measured both before and after occlusion. Seventy-two hours following the permanent MCA occlusion, the neurological outcome was assessed and a quantitative neuropathologic examination was performed in all rabbits. The neurological outcome was better in the rabbits treated with U-74006F plus mannitol than in the other groups. The size of infarction of the affected hemisphere following MCA occlusion was 49.7% in the control group, 30.6% in the U-74006F group, 47.6% in the mannitol group, and 24.1% in the U-74006F plus mannitol group. There was a statistically significant reduction in infarct size in the U-74006F plus mannitol group compared with the other groups (P < 0.05). The ratio of ischemic neurons to total neurons in the cortex was smaller in the U-74006F plus mannitol group than in the other groups. The ratio of ischemic neurons to total neurons in the subcortex was significantly lower in the U-74006F plus mannitol group than in the other groups (P < 0.05). Our data provide evidence for the beneficial effects of both U-74006F and U-74006F plus mannitol in promoting neurological recovery and preservation of the ischemic area.

Successful surgical treatment of a thalamic hydatid cyst with contralateral transcallosal approach. Case report and review of the literature.

An extremely rare case of a thalamic hydatid cyst is presented and the literature is reviewed. A right thalamic hydatid cyst without rim enhancement or perifocal edema was detected by computed tomography and magnetic resonance. This lesion was extirpated successfully with intact contents via contralateral transcallosal approach. To our knowledge, this is the second hydatid cyst of the thalamus, an unusual location, and the first hydatid cyst to be removed completely with intact contents reported in the literature.

Failure of open third ventriculostomy for shunt infections in infants.

Open third ventriculostomy (OTV) was performed on 4 infants with noncommunicating hydrocephalus and intractable shunt infections. All patients were resistant or relapsed after treatment with intravenous and intraventricular antibiotics along with change of the shunt apparatus. We performed phase-contrast cine magnetic resonance imaging (MRI) for preoperative and postoperative evaluation of cerebrospinal fluid (CSF) flow at the aqueduct of Sylvius. All patients required a second OTV approximately 3 weeks after the first OTV due to closure of the patency. Our experience led us to view OTV as an unsuccessful procedure in infantile noncommunicating hydrocephalus due to an insufficiently developed subarachnoid space. The patients' data, operative findings and probable causes of failure are presented here.

Lipid peroxidation and oedema in experimental brain injury: comparison of treatment with methylprednisolone, tirilazad mesylate and vitamin E.

Trauma-induced lipid peroxidation (LP) is one of the most important factors that produces tissue damage in head trauma. In the present study, the protective effects of free radical suppression with methylprednisolone (MP), tirilazad mesylate (TM) and vitamin E on the development of cerebral LP and oedema resulting from head trauma have been investigated. Rats were divided randomly into four groups. Bolus injections of physiological saline, MP (initial 30 mg/kg for 1 h, continuing administration of 5.4 mg/kg per hour until 24 h), TM (10 mg/kg), or vitamin E (30 mg/kg) were given 1 h after the head trauma. The animals were killed 24 h after the weight-drop injury for removal of the brain, and the malondialdehyde (MDA) level and water content of the brain were determined. Rats treated with TM had MDA levels which decreased significantly in comparison with the control group (P<0.03), and none of the drugs had an effect on LP and water content of the brain (P>0.05) that was statistically different. These findings demonstrated the beneficial effect of TM in this model of experimental brain injury.

A new subtype of meningioma.

Three patients with small meningiomas presented with diffuse cerebral edema that was out of proportion to the size of tumors. All lesions were small and no brain invasion or unusual tumor vascularity or dural sinus involvement was noted in any of the three cases. Tumor material was subjected to conventional and immunohistochemical stains. All three tumors showed benign meningothelial components, prominent formation of hyaline inclusions (pseudopsammoma bodies), and striking vascular mural proliferation of small dark cells. All patients have remained asymptomatic without any evidence of tumor recurrence after a follow-up of 4-6 years. These tumors showed proliferation of pericytes in blood vessel walls and, therefore, represent a new subtype of meningothelial meningioma. In the study presented here, the location, size, histotype, and clinical findings that may influence the development of peritumoral brain edema are discussed in detail.

Growing skull fracture of the orbital roof. Case report.

Growing skull fractures are rare complications of head trauma and very rarely arise in the skull base. The clinical and radiological finding and treatment of a growing fracture of the orbital roof in a 5-year-old boy are reported, and the relevant literature is reviewed. The clinical picture was eyelid swelling. Computed tomography (CT) scan was excellent for demonstrating the bony defect in the orbital roof. Frontobasal brain injury seems to play an important role in the pathogenesis of the fracture growth. Growing skull fracture of the orbital roof should be considered in the differential diagnosis in cases of persistent ocular symptoms. Craniotomy with excision of gliotic brain and granulation tissue, dural repair and cranioplasty is the treatment of choice.

Effect of methylprednisolone, tirilazad mesylate and vitamin E on lipid peroxidation after experimental spinal cord injury.

Effect of methylprednisolone (MP), tirilazad mesylate (TM) and vitamin E on lipid peroxidation (LP) was evaluated in an experimental model of spinal cord compression injury in anesthetized rats. Forty rats, divided randomly into four groups, were injured by compressing on the spinal cord at Th 3 for 1 min. Bolus injections of saline solution, MP (30 mg/kg bolus and 5.4 mg/kg/h), TM (10 mg/kg four times per day), or vitamin E (30 mg/ kg four times per day) were begun 1 h after the spinal cord injury (SCI). Twenty-four hours after treatment, the rats were killed, and malondialdehyde (MDA), a LP product, was measured in the spinal cord tissues. Rats treated with MP, TM and vitamin E had significantly decreased MDA levels (P<0.01) than rats in the control group. The lowest MDA levels were found in the TM group. These results suggest that MP, TM and vitamin E may have a protective effect against SCI in rats by its antioxidant effect.

Migration of abdominal catheter of ventriculoperitoneal shunt into the scrotum.

Four cases of migration of the ventriculoperitoneal (V-P) shunt tip through patent processus vaginalis resulting in scrotal hydrocele are presented. These cases are considered a rare complication of V-P shunts and causal mechanisms are discussed with a review of the literature.

Acute spontaneous subdural hematoma of arterial origin: a report of five cases.

Acute spontaneous subdural hematoma of arterial origin is very rare. We report five patients who presented with a history of sudden onset of severe headache and vomiting and who developed progressive neurologic deficits, three becoming comatose. The symptomatologic onset was indistinguishable from other cerebrovascular disorders; none of the patients had a history of head trauma. In all our patients, the source of bleeding was identified at operation as a cortical artery located near the Sylvian region. Comparable cases in the literature are reviewed and the etiologic possibilities are discussed.