Shih-Tseng Lee

Chang Gung Memorial Hospital, T’ai-pei, Taipei, Taiwan

Are you Shih-Tseng Lee?

Claim your profile

Publications (107)172.52 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: A medical record is an important source of information regarding medical care and medical record review plays an important role in the evaluation of the teaching proficiency. The study analyzed the difference between internal and external auditing when conducting medical record review for faculty promotion in a study institute. Methods: We analyzed the scores related to the medical records maintained by applicants for the faculty promotion of attending physicians during the period between 2008 and 2010 at the Chang Gung Memorial Hospital. The scores were obtained from one internal reviewer of the study institute and two external reviewers from other medical centers, and routine scores were obtained from the Committee of Medical Record 1 year before application. Pearson's correlation coefficient was used to analyze the correlation and statistical significance. Results: There were 259 applicants for faculty promotion enrolled in this study [professors (n = 33, 13%), associate professors (n = 63, 24%), assistant professors (n = 90, 35%), lecturers (n = 73, 28%)]. The scores of the external reviewers 1 and 2 were correlated with routine scores (r = 0.187, p = 0.002; r = 0.198, p = 0.001; N= 259), respectively. The correlation between external reviewers' average and ordinary scores was significant for assistant professor (r = 0.334, p = 0.001, n = 90) and professor grades (r = 0.469, p = 0.006, n = 33). However, the internal reviewer scores did not correlate with the routine scores (r = 0.073, p = 0.241, N = 259). Conclusions: The scores from external reviewers correlated more with routine scores than the scores from internal reviewers, suggesting that utilizing an external auditing system of medical records for the faculty promotion of attending physicians is quite feasible and balanced.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The 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. Twenty-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. Thirteen 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. For 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. Copyright © 2014 Elsevier B.V. All rights reserved.
    Clinical Neurology and Neurosurgery 11/2014; 128C:112-116. DOI:10.1016/j.clineuro.2014.11.009 · 1.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This is a retrospective cases series.Objective Tropical pyomyositis of Erector Spinae muscle (ESPM) is a rare muscular infection which may extend into the intraspinal canal to become spinal epidural abscess (ESPM-SEA). If left untreated, it may cause catatrophic spinal cord dysfunction and lead to irreversible paralysis. A series of eight such cases is present, in order to provide proper surgical options and clarify the prognostic factors of the disease.Summary of Background DataMerely six sporadic case reports had been found in the literature. Surgical debridement and laminectomy to drain the intraspinal abscess combined with systemic antibiotics were the choice of treatment to treat the disease with good therapeutic effect.Methods Inpatient charts of the patients were reviewed. The therapeutic effect and functional neurological recovery are correlated with the demographic characteristics of the patients, neurological deficits before drainage, and the different procedures of drainage.ResultsOld age, long ESPM-SEA (>6.5 vertebral segments), spinal cord dysfunction as well as complete paralysis before the interventional procedures is significantly correlated with poor functional neurological recovery (Sperman's coeffiecient correlation, all p < 0.05). Pig-tail drainage of ESPM combined with adequate systemic antibiotics could cure if infection presents with lumbar radiculopathy only, but it failed to rescue the spinal cord dysfuction in two patients presents with complete paralysis. Surgical drainage of ESPM with mini-laminotomy to drain ESPM-SEA combined with systemic antibiotics provided good functional recovery of patients, despite of prolonged pre-operative complete paralysis.Conclusion Early drainage of the ESPM and related epidural abscess combined with systemic antibiotics can provide excellent therapeutic effect of ESPM-SEA. Open drainage with mini-laminotomy is superior to pig-tail drainage when spinal cord dysfunction occurred associated with ESPM-SEA.
    Clinical Neurology and Neurosurgery 11/2014; 128. DOI:10.1016/j.clineuro.2014.10.022 · 1.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective This study uses a validated learning style inventory to delineate the learning style that best defines a successful practitioner in the field of neurosurgery. Methods The Kolb Learning Style Inventory (LSI), a validated assessment tool, was administered to all practicing neurosurgeons, neurosurgical residents, and neurology residents employed at Chang Gung Memorial Hospital, an institution that provides both primary and tertiary clinical care, in three locations, Linkou, Kaohsiung, and Chiayi. Eighty-one participants entered the study and all completed the study. Results Neurosurgeons preferred the assimilating learning style (52%), followed by the diverging learning style (39%). Neurosurgery residents were slightly more evenly distributed across the learning styles, however, they still favored assimilating (32%) and diverging (41%). Neurology residents had the most clearly defined preferred learning style with assimilating (76%) obtaining the large majority, and diverging (12%) being a distant second. Conclusions The assimilating and diverging learning styles are the preferred learning styles among neurosurgeons, neurosurgery residents, and neurology residents with the assimilating learning style typically being the primary learning style for neurosurgeons and neurology residents. Neurosurgical residents start off with a diverging learning style and progress towards an assimilating learning style as they works towards becoming practicing neurosurgeons. The field of neurosurgery has limited opportunities for active experimentation which may explain why individuals that prefer reflective observation are more likely to succeed in this field.
    World Neurosurgery 09/2014; 82(3-4). DOI:10.1016/j.wneu.2014.04.067 · 2.42 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: 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 cm(3) 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. © 2014 S. Karger AG, Basel.
    Cerebrovascular Diseases 06/2014; 37(5):342-349. DOI:10.1159/000360756 · 3.70 Impact Factor
  • Po-Chuan Hsieh, Shih-Tseng Lee, Jyi-Feng Chen
    [Show abstract] [Hide abstract]
    ABSTRACT: Degenerative spondylolisthesis of the spine is less common in the lower thoracic region than in the lumbar and cervical regions. However, lower thoracic degenerative spondylolisthesis may develop secondary to intervertebral disc degeneration. Most of our patients are found to have concomitant lumbar spondylosis. By retrospective review of our cases, current diagnosis and treatments for this rare disease were discussed. We present a series of 5 patients who experienced low back pain, progressive numbness, weakness and even paraparesis. Initially, all of them were diagnosed with lumbar spondylosis at other clinics, and 1 patient had even received prior decompressive lumbar surgery. However, their symptoms continued to progress, even after conservative treatments or lumbar surgeries. These patients also showed wide-based gait, increased deep tendon reflex (DTR), and urinary difficulty. All these clinical presentations could not be explained solely by lumbar spondylosis. Thoracolumbar spinal magnetic resonance imaging (MRI), neurophysiologic studies such as motor evoked potential (MEP) or somatosensory evoked potential (SSEP), and dynamic thoracolumbar lateral radiography were performed, and a final diagnosis of lower thoracic degenerative spondylolisthesis was made. Bilateral facet effusions, shown by hyperintense signals in T2 MRI sequence, were observed in all patients. Neurophysiologic studies revealed conduction defect of either MEP or SSEP. One patient refused surgical management because of personal reasons. However, with the use of thoracolumbar orthosis, his symptoms/signs stabilized, although partial lower leg myelopathy was present. The other patients received surgical decompression in association with fixation/fusion procedures performed for managing the thoracolumbar lesions. Three patients became symptom-free, whereas in 1 patient, paralysis set in before the operation; this patient was able to walk with assistance 6 months after surgical decompression. The average Nurick scale score improved from 3.75 before the operation to 2 after the operation. Lower thoracic degenerative spondylolisthesis is a rare disease, which may occur concomitantly with lumbar spondylosis and confuse clinicians. Diagnosis should be made properly, especially because symptoms/signs cannot be explained purely on the basis of the available images. Micromotion due to facet joint laxity and disc degeneration was believed as the cause of progressive myelopathy. Posterior decompression with fixation/fusion procedure was appropriate for the treatment of thoracic spondylolisthesis secondary to thoracic disc degeneration.
    Clinical neurology and neurosurgery 03/2014; 118C:21-25. DOI:10.1016/j.clineuro.2013.11.019 · 1.25 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This work investigates the calibration of a stereo vision system based on two PTZ (Pan-Tilt-Zoom) cameras. As the accuracy of the system depends not only on intrinsic parameters, but also on the geometric relationships between rotation axes of the cameras, the major concern is the development of an effective and systematic way to obtain these relationships. We derived a complete geometric model of the dual-PTZ-camera system and proposed a calibration procedure for the intrinsic and external parameters of the model. The calibration method is based on Zhang's approach using an augmented checkerboard composed of eight small checkerboards, and is formulated as an optimization problem to be solved by an improved particle swarm optimization (PSO) method. Two Sony EVI-D70 PTZ cameras were used for the experiments. The root-mean-square errors (RMSE) of corner distances in the horizontal and vertical direction are 0.192 mm and 0.115 mm, respectively. The RMSE of overlapped points between the small checkerboards is 1.3958 mm.
    Proceedings of SPIE - The International Society for Optical Engineering 01/2014; DOI:10.1117/12.2041039 · 0.20 Impact Factor
  • Mathematical Problems in Engineering 01/2014; 2014:1-8. DOI:10.1155/2014/526781 · 1.08 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: Cervios ChronOS (CCOS) is a cervical cage containing artificial bone. To date, very few reports have documented the results of its clinical outcome. This study describes the outcomes of CCOS for anterior cervical discectomy with interbody fusion (ACD-IBF) in patients at the Chang Gung Memorial Hospital. Materials and Methods: Retrospectively reviewed 32 patients underwent ACD-IBF with 51 CCOS cages from 2007 to 2008. All patients had either intractable preoperative cervical radiculopathy or myelopathy for 3 months duration and underwent follow-up for >2 years. Postoperative outcomes were classified as favorable or unfavorable. Rigid bone fusion was defined as an interspinous distance ≤2 mm on dynamic lateral cervical radiographs and absence of radiolucent gaps between vertebral endplates and CCOS. Anterior disk height and interbody height were used for subsidence evaluation. Results: The postoperative outcomes were favorable in 86.7% and unfavorable in 13.3% of the patients. Two years after surgery, 90.01% had rigid bone fusion. The anterior disk height was increased at postoperative day 1 and month 3 (P<0.05), but gradually decreased to the preoperative height at sixth month (P>0.05). The interbody height did not change significantly throughout the follow-up. The segmental angle had significant lordosis at postoperative day 1 and month 3 (P<0.05), but kyphotic changes gradually restored the preoperative angle. The clinical outcome was significantly related to the rigid bone fusion rate (P=0.0186). Furthermore, smoking was a contributing factor to poor clinical outcome (P=0.035), and diabetes mellitus was a contributing factor to poor interbody fusion (P=0.009) Conclusions: The CCOS cage can be safely and effectively used as a disk substitute after ACD-IBF. In diabetes mellitus patients, adjuvant-fixation instruments might improve postoperative bone fusion.
    Neurosurgery Quarterly 01/2014; 24(3):161-166. DOI:10.1097/WNQ.0b013e31828cc3d7 · 0.09 Impact Factor
  • Article: Response.
    Ching-yi Lee, Shih-Tseng Lee
    Journal of neurosurgery. Spine 12/2013; 19(6):795. · 2.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Anterior cervical disectomy and fusion (ACDF) is a highly effective and safe method for spinal cord and cervical root decompression. However, vocal cord paralysis (VCP) remains an important cause of postoperative morbidity. The true incidence and recovery course of postoperative VCP is still uncertain. This study is a report on VCP after ACDF to evaluate the incidence, recovery course, and possible risk factors. From 2004 to 2008, 1,895 consecutive patients underwent ACDF in our hospital and were followed up for at least 3 years. All surgeons were well trained and used a right-sided exposure. Prolonged VCP, where patients suffered from postoperative VCP lasting more than 3 months, was recorded and analyzed. In this retrospective study, 9 of the 1,895 patients (0.47 %) documented prolonged VCP lasting over 3 months. Six of the nine patients had total recovery within 9 months. Only three patients (0.16 %) still had symptoms even after 3 years postoperatively. All symptoms of VCP, except hoarseness, could be improved. After matching with 36 non-VCP patients, no differences with regard to longer operative or anesthesia time, shorter neck, obesity, and prevertebral edema. All cases of prolonged course of postoperative VCP occurred in patients who underwent exposure at the C67 level. In our study, only 0.47 % documented prolonged postoperative VCP, while most patients recovered within 9 months. However, if symptoms last longer, there could be almost permanent VCP (0.16 %). In our study, choking and dysphagia subsided mostly within 6 months, but hoarseness remained. The exposure of the C67 level obviously was a risk factor for postoperative VCP.
    European Spine Journal 11/2013; 23(3). DOI:10.1007/s00586-013-3084-y · 2.47 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Primitive neuro-ectodermal tumors (PNET) are rare malignant brain tumors, mostly undifferentiated, that tend to spread through the cerebrospinal fluid (CSF). Extra-pineal supratentorial PNET in adults are very rare. Published guidelines for adult PNET were not available until 2011, and at our institute surgeons and oncologists did not have consensus on imaging evaluation or treatment protocols between 1994 to 2008. Twenty-two consecutive adult patients with extra-pineal supratentorial PNET from this period were reviewed in this retrospective study. Their clinical profiles and radiologic images were evaluated. A pathological review based on the 2007 World Health Organization criteria was also conducted. Prognostic factors were analyzed. The 1 and 3year overall survival rates were 64% and 32% for adult extra-pineal supratentorial PNET, respectively. Limited by the small number of tumors in this series, we suggest that negative prognostic factors are multiplicity at onset, initial CSF seeding, and tumor differentiation. Although age of onset, extent of resection, radiation and chemotherapy were assumed to be good prognostic factors, the analysis did not reveal strong significance for overall survival with univariate and multivariate analysis. We believe more detailed investigations on the genetic/molecular basis of supratentorial PNET and their clinical outcomes are warranted.
    Journal of Clinical Neuroscience 10/2013; 21(5). DOI:10.1016/j.jocn.2013.07.025 · 1.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Radiosurgery has been proven to be an effective treatment for residual or recurrent pituitary adenomas after surgery. However, it causes severe complications when the optic apparatus is irradiated over the tolerance dose. In this study, we analyzed the feasibility of fractionated stereotactic radiosurgery to treat pituitary tumors close to the optic apparatus. Thirty-four patients from June 2006 to June 2011 with recurrent or residual pituitary adenomas close to (<3mm) the optic apparatus were treated with fractionated stereotactic radiosurgery. Three fractions with a total dose of 2100cGy were applied to the tumors. Imaging, examination of vision, and estimation of hormone level were regularly performed before and after radiosurgery. The mean tumor volume before fractioned stereotactic radiosurgery was 5.06±3.08cm(3) (range: 0.82-12.69cm(3)). After a mean follow up of 36.8±15.7months (range: 16-72months), tumor size was reduced in seven (20.6%) patients and remained the same in the other 27 (79.4%) patients. Vision was improved in one patient and remained stable in the rest. Only one patient developed transient post-treatment diplopia. This study suggests that fractionated stereotactic radiosurgery is safe for treating pituitary adenomas close to the optic apparatus. Studies with more patients and longer follow-up are required to draw definite conclusions.
    Journal of Clinical Neuroscience 09/2013; 21(1). DOI:10.1016/j.jocn.2013.03.024 · 1.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Study Design: Case report.Objective: To report a case of lumbar intraneural hemorrhagic cyst after anticoagulation therapy that caused progressive radiculopathy and cauda equina syndrome. The possible pathogenic mechanism, associated diseases, and treatment options are discussed.Summary of Background Data: Various pathologic processes can cause progressive cauda equina syndrome. However, there have been no reports of progressive cauda equina syndrome due to compression from an intraneural hemorrhagic cyst after anticoagulation therapy.Methods: A case of lumbar intradural intraneural hemorrhagic cyst with progressive cauda equina syndrome after anticoagulation therapy is presented.Results: A 42-year-old female patient complained atpresentation of progressive bilateral lower extremity radiating pain, numbness and urinary difficulty during the previous 2 months. Lumbar magnetic resonance imaging (MRI) revealed an L1 cystic lesion with marked mass effect on the surrounding nerve roots. Complete drainage and excision of the lesion was performed which resulted in excellent postoperative symptoms relief. Pathologic examination revealed no definite neoplastic process except some nerve fibers with hemosiderin stain along the cyst wall. Based on a combination of intraoperative findings and pathology, an intradural intraneural hemorrhagic cyst that developed after systemic anticocagulation therapy was diagnosed.Conclusion: This is the first report of an intradural intraneural hemorrhagic cyst causing progressive cauda equina syndrome due to anticoagulation therapy. Surgical excision of the cyst is the definite treatment of choice.
    Spine 09/2013; 38(20):E1288-90. DOI:10.1097/BRS.0b013e31829e1440 · 2.45 Impact Factor
  • 09/2013; 3(3):110-115. DOI:10.1016/j.jacme.2013.06.004
  • Ching-Yi Lee, Hung-Yi Lai, Shih-Tseng Lee
    [Show abstract] [Hide abstract]
    ABSTRACT: Ganglion cysts of the cruciate ligament are rare and sometimes asymptomatic. The authors present three cases of ganglion cysts of the cruciate ligament with atlantoaxial subluxation, which has rarely been reported previously. Generally, ganglion cysts of the cruciate ligament are reported as case reports. Several theories regarding the process of cyst formation and the development of treatment options have been described. However, trans-oral decompression with total removal of the cyst may be one of the options for treatment of this kind of disease. A retrospective review of three patients, two female and one male patient, with a mean age of 68 years was conducted. The operation performed was a trans-oral decompression with cyst removal for all patients. Clinical outcomes were evaluated after the operation. All patients underwent trans-oral decompression with total removal of the cyst, followed by posterior fusion and pathologic examination of the cyst, revealing myxoid stroma with an absence of synovial linings. The ganglion cysts and synovial cysts of the cruciate ligament are two different diseases with different presentation, pathogenesis, pathophysiology, and pathologic findings.
    Acta Neurochirurgica 08/2013; 155(10). DOI:10.1007/s00701-013-1803-0 · 1.79 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Balloon test occlusion (BTO) is crucial before sacrificing parent arteries. We proposed a simple paradigm combining clinical tolerance with venous phase technique and stump pressure ratio as a criterion for sufficient collateral flow. Internal carotid artery (ICA) occlusion was considered safe for asymptomatic patients who exhibited less than 2 seconds of venous phase delay or had a stump pressure ratio greater than 60%. A total of 37 BTO procedures were performed on 31 patients. Twenty-three patients were monitored clinically and 3 were symptomatic. Venous phase comparison was performed on 27 patients, and 5 failed the test. The stump pressure was measured in all patients, and 7 patients failed the test. In summary, 7 patients failed the BTO, of which 6 received high-flow bypass and 1 of these 6 were symptomatic and exhibited stump pressure ratios less than 60% in the second BTO procedure. Occlusion of the ICA was performed on 29 patients. Only 1 patient developed delayed vasospasm and brain infarction. Adequate collateral flow may be indicated by a stump ratio of 60% or greater with or without a high-flow bypass. Combined with clinical assessment and venous phase technique, ICA occlusion may be a safe option that does not result in delayed ischemic complications.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 07/2013; 22(8). DOI:10.1016/j.jstrokecerebrovasdis.2013.05.036 · 1.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study describes a fast and efficient method that uses a prevalidated videotape of an objective structured clinical examination (OSCE) in a fracture scenario to evaluate raters and to measure the consistency of raters from different subspecialties and with varying levels of seniority. We videotaped clinical scenarios for the purpose of evaluating residents' communication and clinical assessment skills. All orthopedic staff used prevalidated checklists to assess residents' performance in the videotape at 3 different time points. Cronbach's α was calculated to evaluate the internal consistency of the OSCE checklist construct. Kendall's W and KR-20 were used to investigate rater agreement. Expert validity was calculated to compare OSCE experts with the present raters. A high Cronbach's α for the 23-item scale regarding global assessment in all 3 tests confirmed construct validity. Kendall's W showed only moderate interrater reliability. KR-20 was 0.96 for the pretest, 0.968 for the posttest, and 0.892 for the long-term test, indicating high internal consistency. The p-value for expert validity was 0.626 (independent t-test, n.s.). This efficient and fast video-based assessment of raters was reliable and yielded satisfactory rater consistency and some evidence for validity.
    Journal of Surgical Education 03/2013; 70(2):189-92. DOI:10.1016/j.jsurg.2012.11.002 · 1.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In cranioplasty, neurosurgeons use bone grafts to repair skull defects. To ensure the protection of intracranial tissues and recover the original head shape for aesthetic purposes, a custom-made pre-fabricated prosthesis must match the cranial incision as closely as possible. In our previous study (Liao et al. in Med Biol Eng Comput 49:203-211, 2011), we proposed an algorithm consisting of the 2D snake and image registration using the patient's own diagnostic low-resolution and defective high-resolution computed tomography (CT) images to repair the impaired skull. In this study, we developed a 3D multigrid snake and employed multiresolution image registration to improve the computational efficiency. After extracting the defect portion images, we designed an image-trimming process to remove the bumped inner margin that can facilitate the placement of skull implants without manual trimming during surgery. To evaluate the performance of the proposed algorithm, a set of skull phantoms were manufactured to simulate six different conditions of cranial defects, namely, unilateral, bilateral, and cross-midline defects with 20 or 40 % skull defects. The overall image processing time in reconstructing the defect portion images can be reduced from 3 h to 20 min, as compared with our previous method. Furthermore, the reconstruction accuracies using the 3D multigrid snake were superior to those using the 2D snake.
    Medical & Biological Engineering 10/2012; 51(1-2). DOI:10.1007/s11517-012-0972-y · 1.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Decompressive craniectomy has been considered the most attractive option for surgical treatment of malignant middle cerebral artery (MCA) infarction. We retrospectively reviewed the clinical and radiological records of 78 patients with malignant MCA infarction who underwent decompressive craniectomy with dura augmentation over a 6-year period. Twenty-six patients had undergone additional anterior temporal resection during decompressive craniectomy. The overall mortality at 30days after surgery was 25.6% while the mortality rate at 6months after surgery was 30.8%. At 6months after surgery, 30.8% of the patients were considered to have good outcomes, while 69.2% had a poor outcome (16.7% suffered from severe disability, 21.8% remained in a vegetative state, and 30.8% died). Ipsilateral surgery was performed on 48 patients with infarction on the dominant side and on 30 patients with lesions on the non-dominant side. No significant difference was noted between these two groups at the 30-day mortality rate. Although no patient with an infarction on the dominant side recovered effective verbal ability during the 6months of follow-up, there was no significant difference between the two groups in clinical outcome at 6months after surgery. The 30-day survival rate in the 26 patients who underwent additional anterior temporal lobectomy was significantly higher (84.6%) than that in patients who underwent decompressive craniectomy and duroplasty only (69.2%) (p<0.05). However, in patients who survived, this additional procedure does not appear to improve the functional outcome.
    Journal of Clinical Neuroscience 10/2012; 20(1). DOI:10.1016/j.jocn.2012.05.027 · 1.32 Impact Factor