Magnetic Resonance-Guided Focused Ultrasound in Neurosurgery: Taking Lessons from the Past to Inform the Future

Magnetic resonance-guided focused ultrasound (MRgFUS) is a new emerging neurosurgical procedure applied in a wide range of clinical fields. It can generate high-intensity energy at the focal zone in deep body areas without requiring incision of soft tissues. Although the effectiveness of the focused ultrasound technique had not been recognized because of the skull being a main barrier in the transmission of acoustic energy, the development of hemispheric distribution of ultrasound transducer phased arrays has solved this issue and enabled the performance of true transcranial procedures. Advanced imaging technologies such as magnetic resonance thermometry could enhance the safety of MRgFUS. The current clinical applications of MRgFUS in neurosurgery involve stereotactic ablative treatments for patients with essential tremor, Parkinson's disease, obsessive-compulsive disorder, major depressive disorder, or neuropathic pain. Other potential treatment candidates being examined in ongoing clinical trials include brain tumors, Alzheimer's disease, and epilepsy, based on MRgFUS abilities of thermal ablation and opening the blood-brain barrier. With the development of ultrasound technology to overcome the limitations, MRgFUS is gradually expanding the therapeutic field for intractable neurological disorders and serving as a trail for a promising future in noninvasive and safe neurosurgical care.

Principles of anesthesia for craniotomy in awake patients / Principios de la anestesia para craneotomía en paciente vigil

La realización de una craneotomía con el paciente despierto se está utilizando cada vez más en diversas situaciones, como en neurocirugía funcional sobre la estimulación cerebral para tratar la enfermedad de Parkinson y la cirugía para tratar la epilepsia, así como los procedimientos neuroquirúrgicos destinadas a resección de tumores cerebrales en áreas elocuentes. Los principios anestésicos para realizar la craneotomía despierta tienen el objetivo de realización de una analgesia adecuada,sedación, la estabilidad hemodinámica sistémica y la permeabilidad de la vía aérea con el tipo de procedimiento neuroquirúrgico a realizar. El objetivo de este estudio es revisar los principios que rigen la conducta de la anestesia para la neurocirugía que es necesario para lograr la craneotomía con el paciente despierto.

Craniotomy in awake patients is becoming more widely used in a range of situations, such as functional neurology, brain stimulation for treatment of Parkinson disease, surgery for treating epilepsy, as well as in neurological procedures to resect brain tumors in eloquent area. The main anesthesia regimen for craniotomy in the awake patient is chosen to provide the appropriate analgesia, sedation, systemic hemodynamic stability and airway patency for the type of neurosurgical procedure being carried out. The objective of the present study was to conduct a review of the principles governing anesthesia for neurosurgeries involving craniotomy in awake patients.

The value of intraoperative ultrasonography during the resection of relapsed irradiated malignant gliomas in the brain

PURPOSE: The aim of this study was to investigate whether intraoperative ultrasonography (IOUS) helped the surgeon navigate towards the tumor as seen in preoperative magnetic resonance imaging and whether IOUS was able to distinguish between tumor margins and the surrounding tissue. METHODS: Twenty-five patients suffering from high-grade gliomas who were previously treated by surgery and radiotherapy were included. Intraoperatively, two histopathologic samples were obtained a sample of unequivocal tumor tissue (according to anatomical landmarks and the surgeon’s visual and tactile impressions) and a small tissue sample obtained using a navigated needle when the surgeon decided to stop the resection. This specimen was considered to be a boundary specimen, where no tumor tissue was apparent. The decision to take the second sample was not influenced by IOUS. The effect of IOUS was analyzed semi-quantitatively. RESULTS: All 25 samples of unequivocal tumor tissue were histopathologically classified as tumor tissue and were hyperechoic on IOUS. Of the boundary specimens, eight were hypoechoic. Only one harbored tumor tissue (P=0.150). Seventeen boundaries were moderately hyperechoic, and these samples contained all possible histological results (i.e., tumor, infiltration, or no tumor). CONCLUSION: During surgery performed on relapsed, irradiated, high-grade gliomas, IOUS provided a reliable method of navigating towards the core of the tumor. At borders, it did not reliably distinguish between remnants or tumor-free tissue, but hypoechoic areas seldom contained tumor tissue.

Endoscopic versus microscopic transsphenoidal surgery in the treatment of pituitary tumors: systematic review and meta-analysis of randomized and non-randomized controlled trials

ABSTRACT We conducted a systematic review and meta-analysis of randomized and non-randomized controlled trials that compared pure endoscopic with microscopic transsphenoidal surgery (TSS) in the resection of pituitary tumors. Embase, PubMed, Lilacs, and Central Cochrane were used as our data sources. The outcomes were total tumor resection, achievement of biochemical control of functioning adenomas, hospital stay and surgery complications. The randomized trials were analyzed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. Two randomized and three prospective controlled non-randomized studies were included. Two studies, including 68 patients, evaluated total tumor resection and the meta-analysis did not show differences between the groups [RR: 1.45 (95% CI: 0.87, 2.44)]. Three studies involving 65 patients analyzed the achievement of biochemical control and no statistical difference was found [RR: 0.94 (95% CI: 0.7, 1.26)]. All five studies compared the frequency of postoperative complications between intervention and control group and meta-analysis favored for a low rate of postoperative complications in the endoscopic TSS group [(RR: 0.37 (95% CI: 0.16, 0.83)]. Due to the low evidence level and low number of observations, the results of our meta-analysis should not be viewed as a final proof of inferiority or superiority of one approach in relation to the other. More data including higher numbers of observations are needed.

Avaliação anatômica comparativa dos acessos transcorioideo e transforniceal transcorioideo ao terceiro ventrículo / Comparative anatomical assessment of transchoroidal approach and transforniceal transchoroidal approach to the third ventricle

O acesso ao terceiro ventrículo constitui verdadeiro desafio ao neurocirurgião. Nesse contexto, estudos anatômicos e morfométricos são úteis para estabelecer as limitações e as vantagens de determinado acesso cirúrgico. O acesso transcorioideo é versátil e promove exposição adequada da região média e posterior do terceiro ventrículo. Entretanto, a coluna do fórnice limita a exposição da região anterior do terceiro ventrículo. Há evidências de que a secção ipsilateral da coluna do fórnice tenha pouca repercussão na função cognitiva. Esta tese compara a exposição anatômica proporcionada pelo acesso transforniceal transcorioideo com o do acesso transcorioideo e realiza avaliação morfométrica de estruturas relevantes e comuns aos dois acessos. Material e métodos: A exposição anatômica proporcionada pelos acessos transcaloso transcorioideo e transcaloso transforniceal transcorioideo foram comparadas em oito cadáveres não submetidos à conservação, utilizando o sistema de neuronavegação (Artis, Brasília, Brasil), para aferir a área de trabalho, a área de exposição microcirúrgica, a exposição angular no plano longitudinal e transversal de dois alvos anatômicos (túber cinéreo e aqueduto cerebral). Adicionalmente, foram quantificados a espessura do parênquima do lobo frontal direito, a espessura do tronco do corpo caloso, o diâmetro longitudinal do forame interventricular, a distância de trabalho da superfície cortical ao túber cinéreo e a distância de trabalho da superfície cortical até o aqueduto cerebral. Os valores obtidos foram submetidos a análise de estatística utilizando o teste de Wilcoxon. Resultados: Na avaliação quantitativa, o acesso transforniceal transcorioideo proporcionou maior área de trabalho (transforniceal transcorioideo = 150,299 +/- 11,147 mm2; transcorioideo = 121,421 +/- 7,698 mm2; p < 0,05), maior área de exposição microcirúrgica (transforniceal transcorioideo = 100,920 +/- 8,764 mm2; transcorioideo = 79,944 +/- 4,954 mm2; p <...

Approaches to the third ventricle constitute a formidable challenge to the neurosurgeon and, in this context, anatomical and morphometric studies are useful to establish the limitations and advantages of certain surgical approaches. The transchoroidal approach is a versatile one that promotes adequate exposure of the middle and posterior regions of the third ventricle. However, the column of fornix limits the exposure of the anterior third ventricle region. There is evidence that the ipsilateral section of the column of fornix has little effect on the cognitive function. This thesis compares the anatomical exposure using the transchoroidal transforniceal technique with the transchoroidal approach, and performs morphometric assessment of relevant structures common to both approaches. Material and methods: The anatomical exposure achieved through the transchoroidal transcallosal approach and transchoroidal transforniceal transcallosal were compared in 8 fresh cadavers using the neuronavigation system (Artis, Brasilia, Brazil), to assess the working area, microsurgical exposure area, to quantify the angular exposure in the longitudinal and cross-sectional planes to two anatomical targets (tuber cinereum and cerebral aqueduct), to measure the thickness of the right frontal lobe parenchyma, corpus callosum body thickness, longitudinal diameter of the interventricular foramen, working distance from the cortical surface to the tuber cinereum and working distance from the cortical surface to the cerebral aqueduct. The values obtained were submitted to statistical analysis using Wilcoxon's test. Results: In the quantitative assessment, the transchoroidal transforniceal approach provided: larger working area (transchoroidal transforniceal = 150.299 +/- 11.147 mm2; transchoroidal = 121.421 +/- 7.698 mm2; p < 0.05), larger area of microsurgical exposure (transforniceal transchoroidal = 100.920 +/- 8.764 mm2; transchoroidal...

Surgical Recanalization of Distal Middle Cerebral Artery Occlusion Due to a Coil Migration During Endovascular Coil Embolization: A Case Report

Coil migration into the parent artery during endovascular coil embolization is a rare, but life-threatening complication, which can induce thromboembolism and result in poor outcome. A 63-year-old man was referred to Chonbuk National University Hospital emergency center due to migration of a coil for a left middle cerebral artery bifurcation unruptured aneurysm. We performed an emergency craniectomy to remove the coil migrated to the distal M2 branch and thrombus, and aneurysmal neck clipping for his aneurysm. Fortunately, at the six month follow-up, the patient did not show any noticeable neurological sequela. In case of parent artery occlusion due to coil migration an immediate recanalization should be performed by a neurovascular specialist who can provide both surgical treatment and endovascular management in order to prevent severe sequela or even death.

Disseminated Invasive Aspergillosis with Multiple Brain Abscess after Allogeneic Hematopoietic Stem Cell Transplantation Treated Successfully with Voriconazole and Neurosurgical Intervention

Invasive aspergillosis is a serious infectious complication, which can occur after hematopoietic stem cell transplantation (HSCT). In particular, despite antifungal treatment, invasive aspergillosis involving the central nervous system (CNS) shows very high mortality. In principle, a neurosurgical procedure with an antifungal agent is recommended for treatment of CNS invasive aspergillosis. We encountered a patient suffering from disseminated invasive aspergillosis involving the lung, brain, and soft tissues after allogeneic HSCT for treatment of relapsed acute myeloid leukemia who was cured with voriconazole and stereotactic drainage of the brain abscess.

Efficacy of Short-Term versus Long-Term Post-Operative Antimicrobial Prophylaxis for Preventing Surgical Site Infection after Clean Neurosurgical Operations / 대한신경손상학회지

OBJECTIVE: Surgical site infection (SSI) is a problem constantly uppermost in the minds of all surgeons, although the actual rate of occurrence is only 1-5% in general surgery. In neurosurgical fields, there have been a few papers published about efficacy of post-operative antimicrobial prophylaxis (PAMP) to prevent SSI, compared to well known effectiveness of pre-operative antibiotics. Thus, infection rates of short-term PAMP groups and those of long-term PAMP groups were investigated to evaluate the effectiveness of PAMP and the efficacy of short-term PAMP compared to long-term PAMP for prevention of SSI. METHODS: Between April 2010 and April 2012, we retrospectively analyzed the data of 35 patients in the aneurysmal neck clipping groups (short-term PAMP group: PAMP for 3 days and fewer, long-term PAMP group: PAMP for 10 days and more) and 79 patients in the microdiscectomy groups (short-term PAMP group: 3 days and fewer, long-term PAMP group: PAMP for 6 days and more). RESULTS: In aneurysmal neck clipping groups, SSI occurred 23.1% of short-term PAMP group and 9.1% of long-term PAMP group (p=0.3370). And in microdiscectomy groups, SSI occurred 6.7% of short-term PAMP group and 4.1% of long-term PAMP group (p=0.9840). CONCLUSION: There is no significant difference between the short-term PAMP group and the long-term PAMP group in terms of SSI, regardless of operation type. We therefore suggest that short-term PAMP usage could be an appropriate therapy for preventing SSI in clean neurosurgical operations.

Adequacy of Nutritional Support and Reasons for Underfeeding in Neurosurgical Intensive Care Unit Patients

PURPOSE: The purpose of the study was to identify the adequacy of enteral feeding, and the reason and prevalence of under-nutrition, and to determine the relationships between caloric intake and resulting nutritional parameters among neurosurgical intensive care unit (ICU) patients. METHODS: The participants for this descriptive study were 47 neurosurgical ICU patients who had enteral feeding initiated after ICU admission. Data were collected from the initial day of enteral feeding for 7 days. Data related to enteral feeding, feeding interruptions or delay, prealbumin, and transferrin were collected. RESULTS: The mean age of the participants was 56.62 years. Twenty-six patients did not receive their feeding formula more than once during 7 days, and 11 had interruptions more than 6 times. The mean number of feeding interruptions was 3.23 (SD= 4.47). On the average, only 76.44% of the estimated energy requirement was provided by enteral feeding to the patients. The frequency of underfeeding was 52.17% with respect to enteral feeding. The most frequent reason for the feeding interruption was observation before and after intubation and extubation, which was unavoidable. The next most common reason was gastrointestinal bleeding, mostly due to old clots or trace, followed by residual volume less than 100 mL. Changes in prealbumin and transferrin levels for 7 days between the underfed and adequately fed groups were not statistically significant. CONCLUSION: The management of enteral feeding by nurses was overprotective because of the unpredictable nature of ICU patients in terms of their underlying disease process. The management of feeding intolerance needs to be evidence-based and nurses must consistently follow the protocol that has been supported as a useful measure.

A microscopic anatomy study of the retrosigmoid keyhole approach / 中国医师进修杂志

Objective To observe the microscopic anatomy structures of petroclival region via the retrosigmoid keyhole approach,then provide an anatomic basis for clinical application.Method Six adult cadaveric heads 6xed by 10% formaldehyde solution were used for simulating the retrosigmoid keyhole approach to observe major microscopic anatomy structures.Results By means of adjusting the microscope,structures such as the ipsilateral trigeminal nerves,cranial nerve,acoustic nerve,posterior nerves,anterior and lateral pons,lateral cerebellar hemisphere,anterior inferior cerebellar artery,vertebral artery,posterior inferior cerebellar artery were exposed via this keyhole approach.Conclusion This retrosigmoid keyhole approach is according with the minimally invasive principle,and represents a reasonable option for accessing the petroclival region.

Standardization of Disease, Diagnostic and Neurosurgical Procedures for the Investigation of Korean Neurosurgical Epidemiology - Part 1: Development of Model for Computerization -

OBJECTIVE: The the international classification of disease and surgical procedure has been found to be a lengthy and time-consuming text for use by neurosurgeons. A more subject matter related classification system is needed for use by this specialty. The author has developed a more comprehensive and standardized classification system specified for diagnosis of neurological disease and neurosurgical procedures. METHODS: Standardization of disease was completed by modifying the name of disease according to that which was used for daily report past 10 years, and from textbook of neurosurgery. The fields of international coding are continued in each. Neurosurgical procedures were designated and modified according to Current Procedure Terminology 96. Client-server system will be used for networking and database software applications have been developed. RESULTS: Disease was classified in 14 large categories and 379 subcategories. Diagnosis was classified in 12 large categories and 43 subcategories. Neurosurgical procedure has 20 large and 202 subcategories. The international coding system such as ICD-10 and ICD-9CM is maintained for the diagnosis and procedures to each category. CONCLUSIONS: It could be possible to make and use a standardized database model of disease, diagnosis and neurosurgical procedures to be used by physician.

Resection of neoplasm in fourth ventricle through transtelovelar approach: a clinical study / 解放军医学杂志

Objective To study the advantages and procedure of telovelar approach for resection of the lesion in the fourth ventricle. Methods Telovelar approach to the fourth ventricle was executed in 17 cases. Among these patients, seven were females and 10 were males. The age ranged from 5 years to 49 years with mean age of 26.6 years. Pathologically, there were 5 medulloblastomas, 5 ependymomas, 2 epidermoids, 2 brain cysticercosis, and 3 choroid plexus papillomas. During the operation, the medullotonsillar space of the cerebellomedullary fissure and the urulotonsillar space were sharply dissected to release the tonsils from uvula and medullar oblongata bilaterally. According to the size of the neoplasm, the tela or both tela and velum were incised. The fourth ventricle was exposed adequately and the lesion was removed. All operations were performed with the help of microscope. The dura was sutured securely. Results The space occupying lesions were removed totally in all cases and all patients recovered very well, and threre was no mortality or serious disability. With 3 to 21-month follow-up in 11 cases, no death or serious disability was found, and the CT or MRI in 8 patients showed no recurrence. Conclusion The telovelar approach can provide adequate exposure to remove the lesion in the fourth venticle. The inferior vermis need not be incised, so a minimum amount of brain tissue was injured, and postoperative complication is decreased.

INTRACRANIAL MINIMAL LESIONS REMOVED BY KEYHOLE APPROACH IN THE GUIDANCE OF FRAMELESS STEREOTAXY WITH ROBOT / 解放军医学杂志

To study the procedure in cutting intracranial minimal lesions, intracranial minimal lesions were removed in 9 cases (male 6, female 3.) through keyhole in the guidance of frameless stereotaxy with robot. Robot image navigation orientation system was used to provide 3D images, and then these markers were made sure the coordinates of lesion target to guide the operating approach, locating anatomical structures,size of lesion and lesions to be removed in all the patients. Cases included 2 meningiomas, 2 brain abscess, 1 cyst of cysticercosis, 1 angiocavernoma, 1 metastasis tumors, 1 granuloma and 1 foreign body of metal from Mar 1, 2001 to June 1, 2001. The robot frameless stereotaxy provided accuracy of the intracranial lesions and anatomy. The postoperative neurofunction defects were not found. The outcome of operation was very good. The robot navigation system provided surgical navigational function: localization, orientation and guidance of the cutting intracranial minimal lesions in exact. It is useful in minimally invasive neurosurgery and is a good therapeutic method.