Ting-Chung Wang

Factors affecting graft infection after cranioplasty.

The aim of this study was to identify the risk factors associated with bone grafts infection after cranioplasty. Eighty-four cranioplasties were performed on 75 patients between 2002 and 2006. Cryopreserved bone grafts were used as graft material in group 1 and polymethylmethacrylate (PMMA) was used in group 2. Risk factors including age, gender, time intervals between craniectomy and cranioplasty, mechanism of injury, number of procedures, graft material, and the Glasgow Coma Scale score were compared between groups. Swab culture results and bone graft infection were assessed in group 1. Multiple procedures before cranioplasty and an inadequate time interval between craniectomy and cranioplasty increase the risk of infection after cranioplasty. Swab culture results, age, gender, mechanism of injury, graft material and Glasgow Coma Scale score are not related to infection. The use of PMMA was associated with a relatively low risk of infection (6.25%). Risk of graft infection was not associated with the choice of graft material in the present study. Multiple procedures and insufficient time intervals increase the risk of infection. Interrupting the wound healing process may be the cause of infection. PMMA is a safe material for cranioplasty regardless of previous infection.

Pial arteriovenous fistula: a review of literature

Pial arteriovenous fistula (AVF) is a rare vascular lesion, with less than 120 reported cases in the English literatures (Hoh et al., Neurosurgery 2001;49(6):1351). The angio-architecture, clinical course and therapeutic options are all different from arteriovenous malformation (AVM), dural AVM or other intracranial vascular lesions. A review of literatures to analyse the clinical course of pial AVF was carried out. The presence of varix dictates the clinical course and presentation. Paediatric type had high percentage of varix, and mass effect as clinical presentation while the adult type usually manifest by haemorrhage. Disconnection of direct shunting, either by endovascular or surgically, is sufficient to achieve successful treatment; therefore, total resection of the lesion is unnecessary.

Foramen ovale cannulation guided by intra-operative computed tomography with integrated neuronavigation for the treatment of trigeminal neuralgia

BackgroundRadiofrequency rhizotomy of the Gasserian ganglion for the treatment of trigeminal neuralgia via percutaneous cannulation of the foramen ovale is facilitated by various localization modalities. In our preliminary study, we described the feasibility of computed tomography (CT) using an integrated neuronavigation system to cannulate the foramen ovale.MethodsAnalysis was performed on 42 consecutive patients who underwent cannulation of the foramen ovale for radiofrequency trigeminal rhizotomy guided by CT using an integrated neuronavigation system. The reproducibility and safety of the neuronavigation-guided procedure were evaluated.ResultsOverall, the average dimension of the foramen ovale was 7.1 (1.5) × 4.7 (1.1) mm, and it was successfully cannulated by neuronavigation guidance in 31 (73.8%) patients with a mean cannulation time of 3.1 (0.7) min and an overall procedure time of 68.2 (16.4) min. The remaining 11 (26.2%) patients required subsequent CT guidance for successful puncture of the foramen ovale.ConclusionsThese data demonstrate that neuronavigation-guided cannulation of the foramen ovale can be executed both quickly and safely on an outpatient basis. Additionally, the use of CT with integrated neuronavigation technology provides superior visual-spatial information compared to conventional fluoroscopy, the process of CT scanning, object planning, and neuronavigation-guided intervention can be completed in the same locale, and its application is easy to master and has the potential to enhance procedure tolerability of awake patients.

Dural metastasis from prostatic adenocarcinoma mimicking chronic subdural hematoma

Dural metastasis is rare. In most reported cases, brain CT scan findings are mistaken for subdural hematoma or meningioma. We present here a 72-year-old male with a history of headache and progressive mental status changes. Brain CT scans suggested chronic subdural hematoma. However, the only surgical findings were diffuse thickening of the dura and sclerosis of the temporal bone. Histopathology revealed metastatic prostatic carcinoma. As the surgical approach and prognosis of chronic subdural hematoma and metastatic tumors are completely different, the differential diagnosis of these diseases is very important. A contrast-enhanced brain CT scan is recommended for patients who could possibly have dural metastases.

Hydrocephalus following decompressive craniectomy for malignant middle cerebral artery infarction

OBJECTIVE The aim of this study was to evaluate the incidence of hydrocephalus and understand the influence of hydrocephalus on the functional outcome of patients undergoing decompressive craniectomy for malignant middle cerebral artery (MCA) infarction. METHODS We retrospectively analyzed data of consecutive patients who underwent decompressive craniectomy for malignant MCA infarction. Clinical and imaging data were reviewed to confirm the incidence of hydrocephalus and evaluate the impact of hydrocephalus on functional outcome. The functional outcomes of patients were estimated with the Glasgow outcome score at 1year after stroke onset. RESULTS Seventeen patients who received decompressive craniectomy for malignant MCA infarction from January 2003 to December 2006 were enrolled. Persistent hydrocephalus developed in 5 patients. The functional outcomes in these patients were uniformly poor regardless of cerebrospinal fluid diversion surgery. Our data revealed that functional outcome was related to patient age and the duration from infarction to craniectomy. CONCLUSIONS Persistent hydrocephalus is common in patients who receive decompressive craniectomy for malignant MCA infarction. However, the shunt procedure does not significantly improve the patients clinical condition. The timing of operation in relation to the functional outcome may be critical.

Feasibility of Intraoperative Computed Tomography Navigation System for Pedicle Screw Insertion of the Thoracolumbar Spine

Study Design: A retrospective analysis of feasibility of intraoperative computed tomography (iCT) navigation for pedicle screw insertion of the thoracolumbar spine. Objectives: This study assessed the feasibility of an iCT navigation system by evaluating the screw insertion time, screw revision time, and learning curve of the iCT surgical team in patients who underwent thoracolumbar pedicle screw surgery using this navigation system. Summary of Background Data: The iCT navigation system has been reported to improve the accuracy and safety of pedicle screw insertion. However, the assessment of the feasibility of spinal instrumentation guided by iCT navigation system is limited. Materials and Methods: From the time iCT navigation system was set-up to a period covering 16 months, consecutive patients who underwent thoracic or lumbar spinal pedicle screw surgery were enrolled. The screw insertion and screw revision times were estimated using the system’s automatic time recording between the iCT scans. The insertion time per screw of the first 50 patients not requiring screw revision was also analyzed to evaluate the learning curve of the iCT surgical team. Results: There were 178 patients with a total of 932 pedicle screws. The cortical breach rate was 3.2% and the screw revision rate was 1.4%. The insertion time per screw was 10.2±6.3 minutes and the screw revision time was 13.8±9.9 minutes. The learning curve of the iCT surgical team for pedicle screw insertion guided by this navigation system was not steep, and experience from <10 patients was adequate to provide familiarity with this system. Conclusions: The iCT navigation system is clinically feasible for thoracolumbar pedicle screw surgery. It provides high-level safety and accuracy, as well as ease of screw revision when required.

Motor function improvement in patients undergoing surgery for spinal epidural abscess.

BACKGROUNDSpinal epidural abscess (SEA) is a rare and devastating clinical entity. Definitive diagnosis is usually delayed because most patients present initially with minor or variable symptoms resulting in poor outcome. The clinical outcome of SEA has been associated with various prognostic factors; however, reports on factors relating to motor function improvement after surgical treatment are limited. OBJECTIVEThe aim of this study is to elucidate which clinical factors may affect motor function recovery after surgical treatment of SEA. PATIENT AND METHODSThe clinical features of patients with SEA undergoing surgical drainage and antibiotics treatment were reviewed, and their outcomes were identified and analyzed. RESULTSThe most common presenting symptoms were neck or back pain, motor deficits, and urinary incontinence. The most common underlying medical condition was diabetes mellitus. Leukocytosis (P = .036; odds ratio [OR] = 0.754; confidence interval [CI] = 0.579–0.982), elevated C-reactive protein level (P = .017; OR 0.96; CI = 0.965–0.994), poor glycemic control (P = .012; OR = 23.33; CI = 1.992–273.29), and duration of motor deficit at the time of operation (P = .005; OR = 40.50; CI = 3.093–530.293) were found to have a strong influence on motor function improvement after surgical treatment. CONCLUSIONInfection control and the prevention of further neurological deterioration in time are paramount in the treatment of SEA for optimal recovery. Patients with rapid neurological deterioration or higher white blood cell count or C-reactive protein level on presentation warrant aggressive surgical intervention; even in those who are completely paralyzed, an improvement in muscle power may still be possible.

Brain protection by methylprednisolone in rats with spinal cord injury.

Traumatic spinal cord injury is clinically treated by high doses of methylprednisolone. However, the effect of methylprednisolone on the brain in spinal cord injury patients has been little investigated. This experimental study examined Bcl-2 and Bax protein expression and Nissl staining to evaluate an apoptosis-related intracellular signaling event and final neuron death, respectively. Spinal cord injury produced a significant apoptotic change and cell death not only in the spinal cord but also in the supraventricular cortex and hippocampal cornu ammonis 1 region in the rat brains. The treatment of methylprednisolone increased the Bcl-2/Bax ratio and prevented neuron death for 1–7 days after spinal cord injury. These findings suggest that rats with spinal cord injury show ascending brain injury that could be restricted through methylprednisolone management.

Noninvasive monitoring of tumor growth in a rat glioma model: comparison between neurological assessment and animal imaging.

Malignant gliomas are the most common primary tumors that arise from glial cells and are characterized by extensive invasiveness and rapid progression. Limitation of the current therapeutic regimen for malignant glioma warrants the development of new therapies strategies. In order to investigate new methods of therapy, establishment of a reliable animal model is essential both in studying the tumor biology and trialing a new therapeutic strategy. Noninvasive monitoring of tumor growth in living animals may be important for new therapeutic strategy development. The development of animal imaging techniques has improved our ability to investigate animal models of malignant gliomas. In this study, both neurological examination and positron emission tomography (PET) with 18F-FDG were used to monitor tumor growth in a rat glioma model. Visual limb placing, tactile limb placing, and beam walking tests were used to assess neurological deficits. Neurobehavioral alterations were correlated with PET findings and histopathological data. Seven days after surgery, the tumor was clearly visible on PET images. Results of behavioral tests correlated well with imaging data and histopathological findings. PET is feasible to detect experimental rat gliomas in their early stage of development. In contrast, standard neurological assessment is useful for monitoring tumor growth during the course of the disease.

Beare-Stevenson cutis gyrata syndrome with chiari malformation

The patient was a male baby who was born after a full-term pregnancy. His mother was 31 years old and his father was 34 years old at the time of his birth. The parents were not consanguineous. The family history was not contributory. There was no maternal illness and drug usage during pregnancy. The pregnancy was uneventful until the 25th gestational week, when a cloverleaf skull was diagnosed by prenatal ultrasonography at Kaohsiung Chang-Gung Memorial Hospital. The infant weighted 2980 gm and was 47 cm long at birth. Clinical examinations showed a cloverleaf skull due to premature closure of multiple cranial sutures. The skin overlying the scalp, face, ears, upper lips and limbs was markedly corrugated. Deep furrows were vertically arranged. The corrugations were also present on the palms, soles and scrotal area. The midfacial region was hypoplastic with small nose and depressed nasal bridge. There was choanal stenosis giving rise to breathing di‰culty. The eyes were prominent with protruding eyeballs. Hypertelorism, downslanting palpebral fissures were also present. The ears were low set and malformed with deep vertical furrows in the preauricular area. The oral cavity was small with a high arched clefted palate. The umbilical stump was large and protruded. Neither acanthosis nigricans, hydrocephalus, nor Chiari malformation was found. Chromosomal analysis using the Giema-banding technique showed a normal 46,XY karyotype and molecular analysis on the FGFR2 gene showed a Tyr 375 Cys substitution (Wang et al., unpublished data). On admission to NICU, an oropharyngeal tube was inserted to facilitate breathing. Nasogastric tube feeding was required because of poor sucking and easily choking. CSF rhinorrhea was noted then. Bilateral fronto-temporal craniectomy with morcellation and repair of the fornto-ethmoid cephalocele was performed 7 days after birth. Tracheostomy was done to relieve upper airway obstruction caused by choanal stenosis at 1 month after birth. CT scan of the head was performed at 4 months old. The results showed markedly dilated ventricles with an obstructive hydrocephalus. A ventriculoperitoneal shunt was inserted at that time. Secondary cranioplasty with transfrontal orbital reconstruction and transoral LeFort I osteotomy of the maxilla was performed to correct hypoplasia of upper and midface at 12 months old. The boy later developed apnea after crying (breath holding spells) and cyanosis 3 months later. MRI showed downward cerebellar herniation not identified in previous MRI examination. Cranioplasty and suboccipital craniectomy were then performed to correct the craniosynostosis and brain herniation. Episodes of apnea and bradycardia markedly decreased after this operation.