Chieh-Tsai Wu

Cranioplasty using polymethyl methacrylate prostheses.

In this retrospective study we attempted to assess the clinical performance of prefabricated polymethyl methacrylate (PMMA) prostheses and to determine whether they outperform intra-operatively moulded PMMA prostheses in reducing operating time, blood loss and surgical complications in elective delayed cranioplasty operations, after decompressive craniectomy, to repair large (> 100 cm2) cranial defects. Patients (n=131) were divided into three groups according to the cranioplasty technique used. Group 1 patients received fresh frozen autograft bone that had been removed at the craniectomy and refrigerated at -80 degrees C. Group 2 included patients whose PMMA prosthesis was moulded intra-operatively. Group 3 patients received a custom-made prefabricated PMMA prosthesis manufactured using computer-aided design/computer-aided manufacturing (CAD/CAM). Group 2 patients required significantly more operating time than both group 1 (p<0.001) and group 3 (p<0.001) patients, but operating time did not differ significantly between groups 1 and 3 (p>0.05). Mean intra-operative blood loss was significantly higher in group 2 than in group 1 (p=0.015) but did not differ significantly between group 1 and group 3 (p>0.05). The infection rate associated with prefabricated PMMA prostheses was lower than that for intra-operatively moulded PMMA prostheses and was comparable to that for autograft bone flaps. A CAD/CAM PMMA prosthesis is an excellent alternative when no autogenous bone graft harvested during craniectomy is available.

In situ local autograft for instrumented lower lumbar or lumbosacral posterolateral fusion

This study evaluated the effectiveness of local in situ autografts in instrumented posterolateral fusion of the lower lumbar or lumbosacral spine for treating degenerative spondylolisthesis. The subjects were 182 degenerative spondylolisthesis patients with spinal canal stenosis who, in one operation, underwent lumbar laminectomy with two-level (L3-4, L4-5 or L5-S1) transpedicle screw/rod system instrumentation and posterolateral fusion using autogenous spinous processes and laminae as the only source of bone grafts. The surgical results were assessed clinically and radiologically. All patients received follow-up for at least eighteen months. At the end of follow-up, bilateral fusion mass was radiographically confirmed in 113 (62%) patients, unilateral fusion mass was observed in fifty-seven (31%) patients, and twelve (7%) patients exhibited no fusion mass at the arthrodesis level. The clinical outcome was rated excellent/good in 138 (76%) patients, fair in thirty-five (19%) and poor in nine (5%). Use of in situ local autografts yields satisfactory clinical results in instrumented posterolateral spinal fusion. No significant correlation was noted between the level of arthrodesis and the radiological outcome, nor between the level of arthrodesis and the clinical outcome. Radiographic evaluation of bony fusion mass was not predictive of the clinical findings.

Classification of symptomatic osteoporotic compression fractures of the thoracic and lumbar spine

The pathophysiology of osteoporotic compression fractures is different from those occurring secondary to traumatic spinal injury, and currently, there is no classification suitable for symptomatic osteoporotic compression fractures treated by percutaneous vertebroplasty. We propose a new classification based on the radiological appearance in the subacute or chronic stage of the clinical presentation of these fractures. They are classified by the authors based on observations and measurements from preoperative and postoperative dynamic lateral radiographs. Compression fractures are divided into two types. Type I is a compression fracture involving the anterior column only. Type II is a fracture involving both the anterior and middle column. Each type is divided into two groups: fractures with union and those with non-union. Type II compression fractures have a higher incidence of non-union than type I (p<0.05). In both type I and II non-union groups, fractures achieve greater increase in vertebral body height after vertebroplasty than both type I and type II union group fractures (p<0.05). In both non-union groups, fractures achieved a greater reduction of kyphotic angle post-vertebroplasty than type I and II union group fractures (p<0.05). Further clinical follow-up of these patients will confirm and extend this classification.

Brain surgery in patients with liver cirrhosis

OBJECTnLiver cirrhosis was identified as an independent predictor of poor outcomes in patients suffering trauma and in those undergoing major surgeries. The aim of this study was to report the authors experiences treating patients with cirrhosis who undergo brain surgeries.nnnMETHODSnBetween 2004 and 2009, 121 consecutive patients with cirrhosis underwent 144 brain procedures. Patients were categorized as Child-Turcotte-Pugh (referred to as Child) Class A, B, or C. The patient profiles, including the severity of cirrhosis, reason for surgery, complications, and prognosis factors, were analyzed.nnnRESULTSnIn this retrospective study, the overall surgical complication rate for patients with cirrhosis was 52.1% and the mortality rate was 24.3%. For patients with acute traumatic brain injury (TBI), the complication, rebleeding, and mortality rates reached 84.4%, 68.8%, and 37.5%, respectively. Surgery for TBI was a significant risk factor for postoperative complications (p = 0.0002) and postoperative hemorrhage (p < 0.0001). Otherwise, according to the Child classification, the complication rate increased in a stepwise fashion from 38.7% to 60% to 84.2%, the rebleeding rate from 29.3% to 48.0% to 63.2%, and the mortality rate from 5.3% to 38% to 63.2% for Child A, B, and C, respectively. The Child classification was associated with higher risk of complications-Child B vs A OR 2.84 (95% CI 1.28-6.29), Child C vs A OR 5.39 (95% CI 1.32-22.02). It was also associated with risk of death-Child C vs A OR 30.43 (95% CI 7.71-120.02), Child B vs A OR 10.88 (95% CI 3.42-34.63).nnnCONCLUSIONSnLiver cirrhosis is a poor comorbidity factor for brain surgery. The authors results suggest that the Child classification used independently is a poor prognostic factor; in addition, grave outcomes were observed in patients with TBI.

Skull base atypical meningioma: long term surgical outcome and prognostic factors.

PURPOSEnThe aim of this study was to examine the clinical outcomes of treating atypical meningioma at the skull base region following surgical resection and adjuvant radiotherapy, and to analyze the association between clinical characteristics and progression free survival.nnnMATERIALS AND METHODSnTwenty-eight patients with skull base atypical meningiomas underwent microsurgical resection between June 2001 and November 2009. The clinical characteristics of the patients and meningiomas, the extent of surgical resection, and complications after treatment were retrospectively analyzed.nnnRESULTSnThirteen patients (46.4%) had disease recurrence or progression during follow up time. The median time to disease progression was 64 months. The extent of the surgical resection significantly impacted prognosis. Gross total resection (GTR) of the tumor improved progression free survival (PFS) compared to subtotal resection (STR, p = 0.011). An older patient age at diagnosis also resulted in a worse outcome (p = 0.024). An MIB-1 index <8% also contributed to improved PFS (p = 0.031). None of the patients that underwent GTR and received adjuvant radiotherapy had tumors recur during follow up. STR with adjuvant radiotherapy tended to result in better local tumor control than STR alone (p = 0.074). Three of 28 patients (10.7%) developed complications after microsurgery. The GTR group had a higher rate of complications than those with STR. There were no late adverse effects after adjuvant radiotherapy during follow up.nnnCONCLUSIONnFor patients with skull base atypical meningiomas, GTR is desirable for longer PFS, unless radical excision is expected to lead to severe complications. Adjuvant radiation therapy is advisable to reduce tumor recurrence regardless of the extent of surgical resection. Age of disease onset and the MIB-1 index of the tumor were both independent prognostic factors of clinical outcome.

A hollow cylindrical PMMA strut for cervical spine reconstruction after cervical multilevel corpectomy.

Study Design: Between January 2002 and December 2005, a prospective study was performed with 14 patients. The patients had cervical diseases and received more than 1 segment anterior cervical corpectomies. Objectives: We investigated the effectiveness of the hollow cylindrical polymethyl methacrylate (PMMA) strut with the autograft for fusion and reconstruction of the cervical spine after multiplelevel cervical corpectomy. Summary of Background Data: We usually used the titanium mesh cage to reconstruct the cervical spine after cervical corpectomy. A significant number of poor outcomes were noted. Because the mesh cage is very hard, it sinks into the vertebral body without the cortex. It is also difficulty to assess the fusion status. Methods: A total of 14 patients (age range: 31 to 76u2009y) underwent anterior cervical corpectomy after fusion and reconstruction with cylindrical PMMA struts. Each patient was reinforced with anterior cervical plate fixation. Follow-up radiographic evaluation was comprised of plain lateral dynamic radiographs and computerized tomography (CT) scans. We evaluated the patients for cervical lordosis and vertebral body height on the basis of plain radiographs. The fusion status was evaluated with CT scans. Neurologic status was assessed preoperative and postoperatively using the Nuricks grading system. Results: The mean follow-up was 48.2 months (range: 28 to 70u2009mo). All patients showed spinal stability at 6 months follow-up on the basis of plain lateral dynamic radiograph results. Thirteen patients showed neurologic improvement with complete bony fusion in the 24-month reconstructed CT scans. There were no complications related to the hollow cylindrical PMMA strut. One patient had loosened screws and required a second operation. Conclusions: The cylindrical PMMA strut provides solid fusion and increased cervical lordosis and vertebral body height. There are few complications associated with the use of this strut, and neurologic recovery is satisfactory. The hollow cylindrical PMMA strut, combined with an anterior cervical plate, is a very successful surgical construct in these patients after long-segmental cervical corpectomy.

The treatment and outcome of postmeningitic subdural empyema in infants

OBJECTnThe management of subdural empyema (SDE) has been debated in the literature for decades. Craniotomy and bur hole drainage have been shown to achieve a favorable outcome. However, there is a lack of comparative data for these modes of management of SDE subsequent to meningitis in infants.nnnMETHODSnThe authors conducted a retrospective review of 33 infants identified with SDE due to meningitis at the Department of Neurosurgery, Chang Gung Memorial Hospital between 2000 and 2006. Preoperative clinical presentation, duration of symptoms, radiological investigations, CSF data, and postoperative outcome were analyzed and compared between these 2 surgical groups.nnnRESULTSnAt diagnosis, there were no differences between the groups in age, weight, degree of consciousness, CSF analysis, or duration of fever. The outcome data showed no difference in the number of days until afebrile, number of days of postsurgical antibiotic treatment, neurological outcome, recurrence rate, or complication rate. There was only 1 death in the series.nnnCONCLUSIONSnSubdural empyema due to meningitis in infants is unique with respect to the pathophysiology, presentation, and treatment of SDE. Early detection and removal of SDE provide a favorable outcome in both surgical intervention groups. Bur hole drainage is less invasive, and it is possible to expect a clinical outcome as good as with craniotomy in postmeningitic SDE.

Long Term Surgical Outcome and Prognostic Factors of Atypical and Malignant Meningiomas.

Atypical and malignant meningiomas are rare. Our aim was to examine the treatment outcomes following surgical resection, and analyze associations between clinical characteristics and overall survival (OS) or relapse free survival (RFS). 102 patients with atypical or malignant meningiomas underwent microsurgical resection between June 2001 and November 2009 were analyzed retrospectively. We compared demographics, clinical characteristics, treatment, and complications. The five-year and ten-year overall survival rates were 93.5% and 83.4%, respectively. Three factors significantly reduced OS: Malignant meningiomas (pu2009<u20090.001), which also decreased RFS (pu2009<u20090.001); female patients (pu2009=u20090.049), and patients with Karnofsky Performance Status (KPS)u2009<u200970 at diagnosis (pu2009=u20090.009). Fifty two patients (51%) experienced tumor relapse. Total resection of tumors significantly impacted RFS (pu2009=u20090.013). Tumors located at parasagittal and posterior fossa area lead to higher relapse rate (pu2009=u20090.004). Subtotal resection without adjuvant radiotherapy lead to the worst local control of tumor (pu2009=u20090.030). An MIB-1 index <8% improved OS and RFS (pu2009=u20090.003). Total resection of atypical and malignant meningiomas provided better outcome and local control. Adjuvant radiation therapy is indicated for patients with malignant meningiomas, with incompletely excised tumors; or with tumors in the parasagittal or posterior fossa area. The MIB-1 index of the tumor is an independent prognostic factor of clinical outcome.

Linear Accelerator Stereotactic Radiosurgery in the Management of Intracranial Arteriovenous Malformations: Long-Term Outcome

Background: Arteriovenous malformation (AVM) is one of the cerebrovascular diseases that bear a high risk of hemorrhage. The treatment modalities include microsurgical resection, endovascular embolization, stereotactic radiosurgery, or combinations that vary widely. Several large series have been reported, while data from Asian populations were few. The aim of this study was to examine the efficacy of linear accelerator stereotactic radiosurgery (LINAC SRS) for the treatment of intracranial AVMs, to evaluate the hemorrhage rate and to analyze associated factors. Methods: One hundred and sixteen patients with AVM were treated with LINAC SRS in a single institute between September 1994 and May 2005 and were retrospectively evaluated. The demographics of patients, clinical characteristics of AVM, the treatment modalities, and the parameters of the LINAC SRS were analyzed. Delayed toxicity and hemorrhage rate after treatment were also evaluated. The AVM obliteration and bleed rates were calculated using the Kaplan-Meier method and Cox regression analyses. Results: The efficacy rate with total obliteration after treatment was 81.9% (95 of 116 patients). The median interval to achieve total obliteration was 49 months. Microsurgical resection combined with SRS for residual AVMs achieved better obliteration rates compared to SRS alone (statistically significant, p = 0.001), while no significant difference was found between the embolization group and the group with no prior treatment (p = 0.895). The Spetzler-Martin grade of AVM is a relative factor of obliteration, higher grades resulting in a worse outcome (p = 0.009). Obliteration was significantly influenced by AVM volume in univariate analysis (p = 0.034), and volume <5 cm3 contributed to improved obliteration (p = 0.01). There was no statistically significant difference in the hemorrhagic rate and the complication rate between ruptured and unruptured AVMs, while the unruptured group had a higher obliteration rate (p = 0.024). The annual hemorrhage rate after LINAC SRS treatment was 1.9%. The bleeding rate was 3.3% in the first year after radiosurgery, 2.1% in the second year, 1.9% between the second and fifth year, and 1.5% between the fifth and tenth year. Patients with hemorrhagic events before radiosurgery appeared to have a higher rebleeding risk during the latency period. Twenty-three patients (19.8%) had late adverse effects with regard to posttreatment radiological follow-up, but only 1 (0.8%) had newly developed neurological deficits. Conclusion: LINAC SRS achieved a high obliteration rate and reduced the risk of hemorrhage effectively in ruptured and unruptured intracranial AVMs. Prior microsurgical resection provided better outcome, while embolization showed no benefit. Adverse effects after treatment are acceptable and require long-term follow-up.

Postoperative midline shift as secondary screening for the long-term outcomes of surgical decompression of malignant middle cerebral artery infarcts.

Decompressive hemicraniectomy (DC) can save the lives of patients with malignant middle cerebral artery (MCA) infarction. We proposed that postoperative midline shift is important for the long-term outcome of patients with MCA infarction. We conducted a retrospective study of DC in 38 patients with malignant MCA infarction. The long-term outcome was assessed one year after surgery using the modified Rankin Scale (mRS) score. Patients who had midline shift less than the optimal diagnostic cut-off point on the fourth postoperative day were classified as having a successful decompression and the remaining patients were classified in the failed decompression group. The successful decompression group mRS score was 4.20±0.89 one year after surgery and the failed decompression group mRS score was 5.11±0.76 (p<0.0001). Successful decompression, resulting in postoperative midline shift of less than 5mm, was a key factor for beneficial, long-term functional outcomes in patients with malignant MCA infarction.