Publications by authors named "Mario Ammirati"

96 Publications

Technological innovation and neurosurgery.

Authors:
Mario Ammirati

Acta Neurochir (Wien) 2021 08 8;163(8):2093. Epub 2021 Jun 8.

Center for Biotechnology Department of Biology, College of Science and Technology, Temple University, Philadelphia, PA, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-021-04854-8DOI Listing
August 2021

Introductions of technological innovations in neurosurgery.

Authors:
Mario Ammirati

Acta Neurochir (Wien) 2020 12 1;162(12):2963. Epub 2020 May 1.

Center for Biotechnology Department of Biology, College of Science and Technology, Temple University, 1900 North 12th Street, Biolife Science Building, Suite 431, Philadelphia, PA, 19122, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-020-04363-0DOI Listing
December 2020

The Effects of Patient Positioning on the Outcome During Posterior Cranial Fossa and Pineal Region Surgery.

Front Surg 2020 13;7. Epub 2020 Mar 13.

Department of Anesthesiology, Stony Brook Medicine, Stony Brook, NY, United States.

Surgery on posterior cranial fossa (PCF) and pineal region (PR) carries the risks of intraoperative trauma to the brainstem structures, blood loss, venous air embolism (VAE), cardiovascular instability, and other complications. Success in surgery, among other factors, depends on selecting the optimal patient position. Our objective was to find associations between patient positioning, incidence of intraoperative complications, neurological recovery, and the extent of surgery. This observational study was conducted in two medical centers: The Ohio State University Wexner Medical Center (USA) and The Burdenko Neurosurgical Institute (Russian Federation). Patients were distributed in two groups based on the surgical position: sitting position (SP) or horizontal position (HP). The inclusion criteria were adult patients with space-occupying or vascular lesions requiring an open PCF or PR surgery. Perioperative variables were recorded and summarized using descriptive statistics. The post-treatment survival, functional outcome, and patient satisfaction were assessed at 3 months. A total of 109 patients were included in the study: 53 in SP and 56 in HP. A higher proportion of patients in the HP patients had >300 mL intraoperative blood loss compared to the SP group (32 vs. 13%; = 0.0250). Intraoperative VAE was diagnosed in 40% of SP patients vs. 0% in the HP group ( < 0.0001). However, trans-esophageal echocardiographic (TEE) monitoring was more common in the SP group. Intraoperative hypotension was documented in 28% of SP patients compared to 9% in HP group ( = 0.0126). A higher proportion of SP patients experienced a new neurological symptom compared to the HP group (49 vs. 29%; = 0.0281). The extent of tumor resection, postoperative 3-months survival, functional outcome, and patient satisfaction were not different in the groups. The SP was associated with, less intraoperative bleeding, increased intraoperative hypotension, VAE, and postoperative neurological deficit. More HP patients experienced macroglossia and increased blood loss. At 3 months, there was no difference of parameters between the two groups. ClinicalTrials.gov: registration number NCT03364283.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fsurg.2020.00009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7082226PMC
March 2020

Surgical management of craniopharyngiomas in adult patients: a systematic review and consensus statement on behalf of the EANS skull base section.

Acta Neurochir (Wien) 2020 05 28;162(5):1159-1177. Epub 2020 Feb 28.

Department of Neurosurgery, University Hospital of Lausanne, Lausanne, Switzerland.

Background And Objective: Craniopharyngiomas are locally aggressive neuroepithelial tumors infiltrating nearby critical neurovascular structures. The majority of published surgical series deal with childhood-onset craniopharyngiomas, while the optimal surgical management for adult-onset tumors remains unclear. The aim of this paper is to summarize the main principles defining the surgical strategy for the management of craniopharyngiomas in adult patients through an extensive systematic literature review in order to formulate a series of recommendations.

Material And Methods: The MEDLINE database was systematically reviewed (January 1970-February 2019) to identify pertinent articles dealing with the surgical management of adult-onset craniopharyngiomas. A summary of literature evidence was proposed after discussion within the EANS skull base section.

Results: The EANS task force formulated 13 recommendations and 4 suggestions. Treatment of these patients should be performed in tertiary referral centers. The endonasal approach is presently recommended for midline craniopharyngiomas because of the improved GTR and superior endocrinological and visual outcomes. The rate of CSF leak has strongly diminished with the use of the multilayer reconstruction technique. Transcranial approaches are recommended for tumors presenting lateral extensions or purely intraventricular. Independent of the technique, a maximal but hypothalamic-sparing resection should be performed to limit the occurrence of postoperative hypothalamic syndromes and metabolic complications. Similar principles should also be applied for tumor recurrences. Radiotherapy or intracystic agents are alternative treatments when no further surgery is possible. A multidisciplinary long-term follow-up is necessary.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-020-04265-1DOI Listing
May 2020

The Role of Decompressive Craniectomy in the Context of Severe Traumatic Brain Injury: Summary of Results and Analysis of the Confidence Level of Conclusions From Systematic Reviews and Meta-Analyses.

Front Neurol 2019 10;10:1063. Epub 2019 Oct 10.

Center for Biotechnology, Department of Biology, College of Science and Technology, Temple University, Philadelphia, PA, United States.

Traumatic brain injury (TBI) is a global epidemic. The incidence of TBI in low and middle-income countries (LMICs) is three times greater than in high-income countries (HICs). Decompressive craniectomy (DC) is a surgical procedure to reduce intracranial pressure (ICP) and prevent secondary injury. Multiple comparative studies, and several randomized controlled trials (RCTs) have been conducted to investigate the influence of DC for patients with severe TBI on outcomes such as mortality, ICP, neurological outcomes, and intensive care unit (ICU) and hospital length of stay. The results of these studies are inconsistent. Systematic reviews and meta-analyses have been conducted in an effort to aggregate the data from the individual studies, and perhaps derive reliable conclusions. The purpose of this project was to conduct a review of the reviews about the effectiveness of DC to improve outcomes. We conducted a systematic search of the literature to identify reviews and meta-analyses that met our pre-determined criteria. We used the AMSTAR 2 instrument to assess the quality of each of the included reviews, and determine the level of confidence. Of 973 citations from the original search, five publications were included in our review. Four of them included meta-analyses. For mortality, three reviews found a positive effect of DC compared to medical management and two found no significant difference between groups. The four reviews that measured neurological outcome found no benefit of DC. The two reviews that assessed ICP both found DC to be beneficial in reducing ICP. DC demonstrated a significant reduction in ICU length of stay in the one study that measured it, and a significant reduction in hospital length of stay in the two studies that measured it. According to the AMSTAR 2 criteria, the five reviews ranged in levels of confidence from low to critically low. Systematic reviews and meta-analyses are important approaches for aggregating information from multiple studies. Clinicians rely of these methods for concise interpretation of scientific literature. Standards for quality of systematic reviews and meta-analyses have been established to support the quality of the reviews being produced. In the case of DC, more attention must be paid to quality standards, in the generation of both individual studies and reviews.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fneur.2019.01063DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6795698PMC
October 2019

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Role of Surgery in the Management of Adults With Metastatic Brain Tumors.

Neurosurgery 2019 03;84(3):E152-E155

Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia.

Please see the full-text version of this guideline https://www.cns.org/guidelines/guidelines-treatment-adults-metastatic-brain-tumors/chapter_2) for the target population of each recommendation listed below.  SURGERY FOR METASTATIC BRAIN TUMORS AT NEW DIAGNOSIS QUESTION: Should patients with newly diagnosed metastatic brain tumors undergo surgery, stereotactic radiosurgery (SRS), or whole brain radiotherapy (WBRT)?

Recommendations: Level 1: Surgery + WBRT is recommended as first-line treatment in patients with single brain metastases with favorable performance status and limited extracranial disease to extend overall survival, median survival, and local control. Level 3: Surgery plus SRS is recommended to provide survival benefit in patients with metastatic brain tumors Level 3: Multimodal treatments including either surgery + WBRT + SRS boost or surgery + WBRT are recommended as alternatives to WBRT + SRS in terms of providing overall survival and local control benefits.  SURGERY AND RADIATION FOR METASTATIC BRAIN TUMORS QUESTION: Should patients with newly diagnosed metastatic brain tumors undergo surgical resection followed by WBRT, SRS, or another combination of these modalities?

Recommendations: Level 1: Surgery + WBRT is recommended as superior treatment to WBRT alone in patients with single brain metastases. Level 3: Surgery + SRS is recommended as an alternative to treatment with SRS alone to benefit overall survival. Level 3: It is recommended that SRS alone be considered equivalent to surgery + WBRT.  SURGERY FOR RECURRENT METASTATIC BRAIN TUMORS QUESTION: Should patients with recurrent metastatic brain tumors undergo surgical resection?

Recommendations: Level 3: Craniotomy is recommended as a treatment for intracranial recurrence after initial surgery or SRS.  SURGICAL TECHNIQUE AND RECURRENCE QUESTION A: Does the surgical technique (en bloc resection or piecemeal resection) affect recurrence?

Recommendation: Level 3: En bloc tumor resection, as opposed to piecemeal resection, is recommended to decrease the risk of postoperative leptomeningeal disease when resecting single brain metastases.

Question B: Does the extent of surgical resection (gross total resection or subtotal resection) affect recurrence?

Recommendation: Level 3: Gross total resection is recommended over subtotal resection in recursive partitioning analysis class I patients to improve overall survival and prolong time to recurrence. The full guideline can be found at https://www.cns.org/guidelines/guidelines-treatment-adults-metastatic-brain-tumors/chapter_2.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/neuros/nyy542DOI Listing
March 2019

Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on Treatment Options for Adults With Multiple Metastatic Brain Tumors.

Neurosurgery 2019 03;84(3):E180-E182

Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia.

Target Population: These recommendations apply to adult patients newly diagnosed with multiple (more than 1) brain metastases.

Question 1: In what circumstances should whole brain radiation therapy be recommended to improve tumor control and survival in patients with multiple brain metastases?

Recommendation: Level 2: It is recommended that whole brain radiation therapy can be added to stereotactic radiosurgery to improve local and distant control keeping in mind the potential for worsened neurocognitive outcomes and that there is unlikely to be a significant impact on overall survival.

Question 2: In what circumstances should stereotactic radiosurgery be recommended to improve tumor control and survival in patients with multiple brain metastases?

Recommendations: Level 1: In patients with 2 to 3 brain metastases not amenable to surgery, the addition of stereotactic radiosurgery to whole brain radiation therapy is not recommended to improve survival beyond that obtained with whole brain radiation therapy alone. Level 3: The use of stereotactic radiosurgery alone is recommended to improve median overall survival for patients with more than 4 metastases having a cumulative volume < 7 cc.

Question 3: In what circumstances should surgery be recommended to improve tumor control and survival in patients with multiple brain metastases?

Recommendation: Level 3: In patients with multiple brain metastases, tumor resection is recommended in patients with lesions inducing symptoms from mass effect that can be reached without inducing new neurological deficit and who have control of their cancer outside the nervous system.The full guideline can be found at https://www.cns.org/guidelines/guidelines-treatment-adults-metastatic-brain-tumors/chapter_6.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/neuros/nyy548DOI Listing
March 2019

Fabrication and characterization of implantable flushable electrodes for electric field-mediated drug delivery in a brain tissue-mimic agarose gel.

Electrophoresis 2018 09 17;39(17):2262-2269. Epub 2018 Jul 17.

School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, USA.

Every forty minutes, one person dies in the USA due to glioblastoma multiforme; a deadly form of brain cancer with an average five-year survival rate less than 3%. The current standard of care for treatment involves surgical resection of the accessible tumor followed by radiation therapy and concomitant chemotherapy. Despite their potency, delivering chemotherapeutic agents to the brain is limited by the highly selective blood-brain barrier, which prevents molecules >500 Da from reaching the brain. Other techniques, such as convection-enhanced delivery, controlled release by drug-loaded wafers or intracerebroventricular infusion have limited clinical utility due to unpredictable targeting and volume of drug distribution. We introduce a novel drug delivery technique that can use direct current electric fields to deliver charged chemotherapeutics to the site of brain parenchyma after tumor resection. We fabricate and characterize an implantable drug delivery system using flushable electrodes to deliver the charged chemotherapeutic or doxorubicin (+1) in a brain tissue-mimic agarose gel (0.2% w/v) model by electrophoresis. The optimized capillary-embedded electrode system exhibited a sustained movement of charged doxorubicin through nearly 3.5 mm in four hours, a distance for achieving effective intratumoral concentrations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/elps.201800161DOI Listing
September 2018

Quantitative evaluation of different far lateral approaches to the cranio-vertebral junction using the microscope and the endoscope: a cadaveric study using a tumor model.

Acta Neurochir (Wien) 2018 04 26;160(4):695-705. Epub 2018 Feb 26.

The Dardinger Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, The Ohio State University, Columbus, OH, USA.

Background: Several far lateral approaches have been proposed to deal with cranio-vertebral junction (CVJ) tumors including the basic, transcondylar, and supracondylar far lateral approaches (B-FLA, T-FLA, and S-FLA). However, the indications on when to use one versus the other are not well systematized yet. Our purpose is to evaluate in an experimental cadaveric setting which approach is best suited to remove tumors of different sizes.

Methods: We implanted at the CVJ, using a transoral approach, tumor models of different sizes (five 1-cm and five 3-cm tumors) in ten embalmed cadaveric heads. The artificial tumors were exposed via the three approaches using endoscopic-assisted microneurosurgical technique and neuronavigation. The skull base area exposed and the maneuverability linked to each approach were evaluated using neuronavigation.

Results: In 1-cm tumors, the T-FLA and the S-FLA exposed a significantly larger skull base area than the B-FLA both using the microscope and the endoscope (P < 0.05); the T-FLA executed with the microscope provided wider vertical and horizontal maneuverability than the B-FLA (P = 0.030 and 0.017, respectively); the S-FLA executed with the endoscope provided wider vertical maneuverability than the T-FLA (P = 0.031). The S-FLA executed using the microscope and the endoscope provided wider vertical maneuverability than the B-FLA both in 1 and 3-cm tumors (P < 0.05).

Conclusions: In 1-cm tumors, the S-FLA and the T-FLA expose a wider skull base area than the B-FLA. In larger tumors, the exposure is similar for all three approaches. Use of the endoscope in an assistive mode may further increase the surgical exposure and maneuverability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-018-3502-3DOI Listing
April 2018

Innovation in neurosurgery response to: "Ideal", the operating microscope, and the parachute.

Authors:
Mario Ammirati

Acta Neurochir (Wien) 2018 02 17;160(2):371. Epub 2017 Dec 17.

St. Rita Medical Center/Mercy Health, Lima, OH, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-017-3427-2DOI Listing
February 2018

NCCN Guidelines Insights: Central Nervous System Cancers, Version 1.2017.

J Natl Compr Canc Netw 2017 11;15(11):1331-1345

For many years, the diagnosis and classification of gliomas have been based on histology. Although studies including large populations of patients demonstrated the prognostic value of histologic phenotype, variability in outcomes within histologic groups limited the utility of this system. Nonetheless, histology was the only proven and widely accessible tool available at the time, thus it was used for clinical trial entry criteria, and therefore determined the recommended treatment options. Research to identify molecular changes that underlie glioma progression has led to the discovery of molecular features that have greater diagnostic and prognostic value than histology. Analyses of these molecular markers across populations from randomized clinical trials have shown that some of these markers are also predictive of response to specific types of treatment, which has prompted significant changes to the recommended treatment options for grade III (anaplastic) gliomas.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.6004/jnccn.2017.0166DOI Listing
November 2017

Innovation in neurosurgery.

Authors:
Mario Ammirati

Acta Neurochir (Wien) 2017 10 16;159(10):1955-1956. Epub 2017 Aug 16.

St. Rita Medical Center/Mercy Health, Lima, OH, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00701-017-3283-0DOI Listing
October 2017

The Changing Health Care Landscape and Implications of Organizational Ethics on Modern Medical Practice.

World Neurosurg 2017 Jun 24;102:420-424. Epub 2017 Mar 24.

Cushing Neurosurgical Outcomes Center, Department of Neurosurgery, Brigham and Women's Hospital, Boston, Massachusetts, USA; Department of Neurosurgery, University Medical Center, Utrecht, The Netherlands. Electronic address:

Introduction: Medicine is rapidly changing, both in the level of collective medical knowledge and in how it is being delivered. The increased presence of administrators in hospitals helps to facilitate these changes and ease administrative workloads on physicians; however, tensions sometimes form between physicians and administrators.

Analysis: This situation is based on perceptions from both sides that physicians obstruct cost-saving measures and administrators put profits before patients. In reality, increasing patient populations and changes in health care are necessitating action by hospitals to prevent excessive spending as health care systems become larger and more difficult to manage. Recognizing the cause of changes in health care, which do not always originate with physicians and administrators, along with implementing changes in hospitals such as increased physician leadership, could help to ease tensions and promote a more collaborative atmosphere. Ethically, there is a need to preserve physician autonomy, which is a tenet of medical professionalism, and a need to rein in spending costs and ensure that patients receive the best possible care.

Conclusion: Physicians and administrators both need to have a well-developed personal ethic to achieve these goals. Physicians need be allowed to retain relative autonomy over their practices as they support and participate in administrator-led efforts toward distributive justice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2017.03.073DOI Listing
June 2017

Ethical clinical translation of stem cell interventions for neurologic disease.

Neurology 2017 Jan 7;88(3):322-328. Epub 2016 Dec 7.

From Cushing Neurosurgery Outcomes Center, Department of Neurosurgery (D.J.C., T.R.S.), Brigham and Women's Hospital, Harvard Medical School, Boston, MA; Department of Medical Humanities, Julius Center (A.L.B.), and Department of Neurosurgery (M.L.B.), University Medical Center, Utrecht, the Netherlands; Department of Neurosurgery (M.A.), Ohio State University, Columbus; Copenhagen Neurosurgery, Neuroscience Centre (J.B.), Rigshospitalet, University of Copenhagen, Denmark; University of Saskatchewan and Saskatoon Health Region, Department of Surgery (I.M.), and Royal University Hospital, Saskatoon, Canada; Department of Neurosurgery (A.S.A.), University of Dammam College of Medicine, Saudi Arabia; Department of Neurosurgery (N.B.), Göztepe Education and Research Hospital, Istanbul, Turkey; Department of Neurosurgery (G.B.), Denver Health Medical Center, University of Colorado School of Medicine; Department of Neurosurgery (I.N.E.), Ain Shams University, Cairo, Egypt; Department of Neurosurgery (T.M.), Karolinska Hospital and Institute, Stockholm, Sweden; and Department of Neurology (M.L.B.), Massachusetts General Hospital, Boston.

The application of stem cell transplants in clinical practice has increased in frequency in recent years. Many of the stem cell transplants in neurologic diseases, including stroke, Parkinson disease, spinal cord injury, and demyelinating diseases, are unproven-they have not been tested in prospective, controlled clinical trials and have not become accepted therapies. Stem cell transplant procedures currently being carried out have therapeutic aims, but are frequently experimental and unregulated, and could potentially put patients at risk. In some cases, patients undergoing such operations are not included in a clinical trial, and do not provide genuinely informed consent. For these reasons and others, some current stem cell interventions for neurologic diseases are ethically dubious and could jeopardize progress in the field. We provide discussion points for the evaluation of new stem cell interventions for neurologic disease, based primarily on the new Guidelines for Stem Cell Research and Clinical Translation released by the International Society for Stem Cell Research in May 2016. Important considerations in the ethical translation of stem cells to clinical practice include regulatory oversight, conflicts of interest, data sharing, the nature of investigation (e.g., within vs outside of a clinical trial), informed consent, risk-benefit ratios, the therapeutic misconception, and patient vulnerability. To help guide the translation of stem cells from the laboratory into the neurosurgical clinic in an ethically sound manner, we present an ethical discussion of these major issues at stake in the field of stem cell clinical research for neurologic disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1212/WNL.0000000000003506DOI Listing
January 2017

Properties and Storage Methods of the Stratathane ST-504-Based Neurosurgical Tumor Model: Comprehensive Analysis.

World Neurosurg 2016 Dec 15;96:350-354. Epub 2016 Sep 15.

Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, Ohio State University, Columbus, Ohio, USA. Electronic address:

Background: Constrains on neurosurgical residents' work hours demand innovative teaching models to complement the traditional "in the operating room" model. Stratathane ST-504 (Strata-Tech, Inc., Des Moines, Iowa, USA) has been proposed as a useful artificial neurosurgical tumor model. The consistency, dissectability, and radio-opacity of this model strongly depend on its preparation and storage. However, little work has addressed the interplay of these properties. Hence our study was undertaken to explore the properties of ST-504, its preparation, and storage and how these interactions affect its radio-opacity and consistency.

Methods: Tumor mixture was prepared by mixing 4.5 mL of water, 1.5 mL of computed tomography contrast medium, 2 mL of ST-504, and 0.5 mg turmeric powder. The tumor mixture was either allowed to solidify, yielding solid tumor blocks, or injected into an anatomic specimen to create a tumor model. Both tumor blocks and tumor model were stored at different temperature, under different storage conditions and for different time. Their volumes, computed tomography appearance, and consistency were evaluated.

Results: The tumor blocks stored in water or ethanol absorbed fluid, resulting in enlargement and associated decrease in radiodensity and consistency. The same results were displayed by the tumor implanted in cadaveric specimen.

Conclusion: For any given ratio of ST-504/water, the time sequence after polymer solidification and the storage method determine the computed tomography appearance and consistency of the tumor block/model. When taking these properties into consideration, ST-504-based artificial tumor models can be customized for different dissection practices, from more solid (meningioma-like) to less solid (schwannoma-like) models.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2016.09.039DOI Listing
December 2016

Is less always better? Keyhole and standard subtemporal approaches: evaluation of temporal lobe retraction and surgical volume with and without zygomatic osteotomy in a cadaveric model.

J Neurosurg 2017 Jul 16;127(1):157-164. Epub 2016 Sep 16.

Dardinger Skull Base Laboratory, Department of Neurological Surgery, Ohio State University Wexner Medical Center, Columbus, Ohio.

OBJECTIVE The subtemporal approach is one of the surgical routes used to reach the interpeduncular fossa. Keyhole subtemporal approaches and zygomatic arch osteotomy have been proposed in an effort to decrease the amount of temporal lobe retraction. However, the effects of these modified subtemporal approaches on temporal lobe retraction have never been objectively validated. METHODS A keyhole and a classic subtemporal craniotomy were executed in 4 fresh-frozen silicone-injected cadaver heads. The target was defined as the area bordered by the superior cerebellar artery, the anterior clinoid process, supraclinoid internal carotid artery, and the posterior cerebral artery. Once the target was fully visualized, the authors evaluated the amount of temporal lobe retraction by measuring the distance between the base of the middle fossa and the temporal lobe. In addition, the volume of the surgical and anatomical corridors was assessed as well as the surgical maneuverability using navigation and 3D moldings. The same evaluation was conducted after a zygomatic osteotomy was added to the two approaches. RESULTS Temporal lobe retraction was the same in the two approaches evaluated while the surgical corridor and the maneuverability were all greater in the classic subtemporal approach. CONCLUSIONS The zygomatic arch osteotomy facilitates the maneuverability and the surgical volume in both approaches, but the temporal lobe retraction benefit is confined to the lateral part of the middle fossa skull base and does not result in the retraction necessary to expose the selected target.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2016.6.JNS16663DOI Listing
July 2017

Expanding the Horizon of the Suboccipital Retrosigmoid Approach to the Middle Incisural Space by Cutting the Tentorium Cerebelli: Anatomic Study and Illustration of 2 Cases.

World Neurosurg 2016 Aug 14;92:303-312. Epub 2016 May 14.

Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA. Electronic address:

Objective: Complex skull base approaches are often used to treat lesions within the middle incisural space; yet the well-known retrosigmoid route may provide an effective avenue to this difficult-to-reach region. The purpose of this study was to quantify the exposure advantages on the middle incisural space provided by cutting of the tentorium cerebelli via a standard suboccipital retrosigmoid approach (i.e., via the cerebellopontine cistern route). Also, 2 illustrative cases are presented.

Methods: A suboccipital retrosigmoid approach to the middle incisural space was performed bilaterally in 3 specimens in the semisitting position. A quantitative analysis of the brainstem surface exposed above the origin of the trigeminal nerve was performed before and after tentorial incision.

Results: Tentorial cutting significantly improved the exposure of the middle incisural space cisternal structures such as the oculomotor and trochlear nerves and the superior cerebellar and posterior cerebral arteries. The mean brainstem surface exposed more than doubled (2.13-fold increase) after tentorial incision with an average increase from 73.18 mm(2) to 155.76 mm(2). When the endoscope was used, it was possible to follow the entire course of the cisternal, infratentorial trochlear nerve segment during the opening of the tentorial free edge, facilitating its preservation. In the illustrative cases, 2 cerebellopontine angle meningiomas with supratentorial and infratentorial extension were removed without any postoperative complication.

Conclusions: Tentorial incision may be useful to extend the rostral exposure of the middle incisural space via a simple retrosigmoid approach, avoiding the need for more complex skull base routes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2016.05.020DOI Listing
August 2016

Intrapetrous Internal Carotid Artery: Evaluation of Exposure, Mobilization and Surgical Maneuvers Feasibility from a Retrosigmoid Approach in a Cadaveric Model.

World Neurosurg 2016 Jul 26;91:443-50. Epub 2016 Apr 26.

Department of Radiology and Wright Center of Innovation in Biomedical Imaging, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA. Electronic address:

Objectives: To provide a quantification of the exposure of the vertical and horizontal segments of the intrapetrous carotid artery (IPCA) and to evaluate the possibilities of its mobilization and of performing surgical maneuvers on it using the retrosigmoid approach.

Methods: Twelve surgical dissections were performed bilaterally on 6 fresh cadavers. Predissection computed tomography (CT) scans with bone fiducials for intraoperative navigation were acquired. A retrosigmoid craniectomy was performed. The inframeatal space was drilled, the horizontal (HoIPCA) and vertical (VeIPCA) segments of the IPCA were exposed, and their measurements were recorded. The carotid canal was enlarged, the artery was carefully detached from the bone, and a vessel loop was inserted in order to mobilize its horizontal segment. Afterwards we performed different surgical maneuvers: We inflated a 5-French Fogarty balloon to compress the IPCA and repaired a 7-mm arteriotomy with a running suture. Specimens underwent a new CT scan to evaluate the amount of bone removal and the integrity of the inner ear structures.

Results: The HoIPCA and VeIPCA were exposed and anatomically preserved in all specimens without injuring the surrounding neurovascular structures. The HoIPCA presented an average length of 24.89 mm (range: 19.41-31.47 mm), and the VeIPCA presented an average length of 10.07 mm (range: 8.92-11.58 mm). The possibility of IPCA mobilization and the feasibility of performing surgical maneuvers were demonstrated. Postdissection CT scan showed the preservation of inner ear structures.

Conclusion: Exposure and mobilization of the IPCA using a retrosigmoid approach are feasible and could represent a viable option for the possibility of reaching a total resection of selected skull base tumors, even when involvement of the carotid canal is present.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2016.04.064DOI Listing
July 2016

Exposing the Fundus of the Internal Acoustic Meatus without Entering the Labyrinth Using a Retrosigmoid Approach: Is It Possible?

World Neurosurg 2016 Jul 13;91:357-64. Epub 2016 Apr 13.

Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA. Electronic address:

Objectives: To evaluate the feasibility of performing a labyrinth-sparing neuronavigation-assisted retrosigmoid approach to the fundus of the internal acoustic meatus (IAM) and to describe the anatomy of the structures embedded in the posterior meatal wall.

Methods: Ten surgical dissections were performed bilaterally on 5 fresh cadavers. Cadavers were subjected to preoperative computed tomography scans and spatial coordinates of inner ear structures were recorded. A retrosigmoid craniectomy was performed. The IAM was drilled towards the fundus until no more than 1 mm of bone covered the labyrinthine structures. Specimens underwent a new computed tomography scan to verify the length of opened IAM and the status of the labyrinth. We then opened the labyrinthine structures and recorded their coordinates using navigation. These were compared with the radiologic coordinates to verify the neuronavigation accuracy.

Results: In 9 sides, the IAM was opened to the fundus without injuring the labyrinth; in 1 side, the vestibule was opened. The mean residual bone on the fundus was 0.97 mm. The average length of the accessible IAM was 88.95%. The best accuracy of the navigation was for the identification of the common crus, with a mean value of 0.73 mm.

Conclusions: This surgical technique could facilitate the opening of the IAM with preservation of inner ear structures. We opened a mean of 88.95% of the IAM without entering the labyrinthine structures in 90% of cases. These results confirm the feasibility of the retrosigmoid approach for the exposure of the IAM fundus with preservation of labyrinthine structures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2016.03.093DOI Listing
July 2016

Quantitative analysis of surgical exposure and surgical freedom to the anterosuperior pons: comparison of pterional transtentorial, orbitozygomatic, and anterior petrosal approaches.

Neurosurg Rev 2016 Oct 14;39(4):599-605. Epub 2016 Apr 14.

Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, The Ohio State University, Columbus, OH, USA.

Surgical approaches to the pons lump together different areas of the pons, such as the anterosuperior and the anteroinferior pons. These areas are topographically different, and different approaches may be best suited for one or the other area. We evaluated the exposure of the anterosuperior pons using different surgical approaches. We quantify the surgical exposure and surgical freedom to the anterosuperior pons afforded by the pterional transtentorial (PT), the orbitozygomatic with anterior clinoidectomy (OZ), and the anterior petrosal (AP) approaches. Five embalmed cadaver heads were used. The three approaches were executed on each side, for a total of 30 approaches. The area of maximal exposure of the anterosuperior pons was measured with the aid of neuronavigation. We also evaluated the feasible angles of approach in the vertical and horizontal planes. We were able to successfully expose the anterosuperior pons using all the selected approaches. In the PT and OZ approaches, mobilization of the sphenoparietal sinus can prevent over-retraction of the temporal bridging veins, while use of the endoscope can help in preserving the integrity of the fourth nerve while cutting the tentorium. The mean exposure area was largest for the AP and smallest for the PT; the surgical freedom was similar among all the approaches. However, there was no statistically significant difference among all the approaches in the exposure area or in the surgical freedom. There is no significant difference among the three evaluated approaches in exposure of the anterosuperior pons.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10143-016-0710-2DOI Listing
October 2016

Microsurgical Anatomy of the Internal Acoustic Meatus as Seen Using the Retrosigmoid Approach.

Otol Neurotol 2016 06;37(5):568-73

*Institute of Neurosurgery, Catholic University of Rome, Rome, Italy †Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio ‡Section of Neurosurgery, Department of Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan §Department of Radiology and Wright Center of Innovation in Biomedical Imaging, Wexner Medical Center, The Ohio State University, Columbus, Ohio.

Hypothesis: To show via a retrosigmoid approach the bony labyrinth anatomy and its relationship with the internal acoustic meatus so as to provide guidelines for a safer drilling to the fundus using this approach.

Background: Few studies deal with the complex anatomy of petrous bone structures as observed by a retrosigmoid approach.

Methods: Ten retrosigmoid approaches were performed bilaterally on five fresh cadaveric heads. Afterward high-resolution computed tomographic scans were obtained. Measurements of landmarks and distances between important topographic structures of the pyramid were obtained on its surface using a navigation system. Semicircular canals, vestibular aqueduct, and internal acoustic meatus were dissected to show their anatomy and relationships.

Results: The anatomy of the inner ear structures was shown. Opening of the internal acoustic meatus was accomplished without injury to the labyrinth in 9 out of 10 sides. The distance between the drilled bone of the internal acoustic meatus and the vestibule was calculated on the postoperative computed tomographic scan. The mean value was 1.43 mm (SD, 0.30 mm; range, 1.0-1.8 mm).

Conclusion: A better knowledge of the anatomy of the semicircular canals and of the vestibular aqueduct as observed by a retrosigmoid approach, together with their relationships to the fundus and other petrous bone landmarks, can be useful to get a general orientation in acoustic neuroma surgery. Using this information together with the neuronavigation, we were able to successfully open the internal acoustic meatus without entering labyrinthine structures in 90% of the study dissections.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/MAO.0000000000001013DOI Listing
June 2016

Functional Petrosectomy Via a Suboccipital Retrosigmoid Approach: Guidelines and Topography.

World Neurosurg 2016 Mar 15;87:143-54. Epub 2015 Dec 15.

Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio, USA. Electronic address:

Objective: Recent reports have validated the use of retrosigmoid approach extensions to deal with posterior fossa lesions extending laterally extracranially or superiorly into the petroclival areas. The purpose of our research is to describe the topographic retrosigmoid anatomy of the petrous pyramid and provide guidelines for neurovascular sparing drilling (hence for a functional petrosectomy), via this surgical route.

Methods: Suprameatal and inframeatal retrosigmoid approach extensions were performed bilaterally in 6 specimens in the semisitting position. Topographic relationships of pertinent labyrinthine landmarks with evident posterolateral cranial base structures were measured by neuronavigation.

Results: Excellent exposure of inframeatal/petroclival regions as well as of the extracranial posterior infratemporal area was achieved in all the specimens. In the inframeatal region, petrous bone drilling was limited by the labyrinth and the internal auditory canal superiorly and by the jugular bulb, the inferior petrosal sinus, and the lower cranial nerves inferiorly. The intrapetrous internal carotid artery represented the anterolateral limit. In the suprameatal area, the drilling was limited laterally by the labyrinth (i.e., by the posterior part of the superior semicircular canal, the upper part of the posterior semicircular canal, and the common crus). The internal auditory canal was the inferior limit, and the superior petrosal sinus and the trigeminal nerve limited the drilling superiorly. Multiple topographic relationships among key landmarks were quantified.

Conclusions: Knowledge of the topographic anatomy of the labyrinthine structures examined may be useful (combined with careful assessment of the preoperative imaging and with the use of neuronavigation and endoscopy) to accomplish a retrosigmoid neurovascular sparing petrosectomy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2015.11.042DOI Listing
March 2016

Petroclival tumor model--technical note and educational implications.

Neurosurg Rev 2016 Apr 1;39(2):251-7; discussion 257-8. Epub 2015 Dec 1.

Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, The Ohio State University Medical Center, Columbus, OH, USA.

Petroclival area lesions are rare, and their surgery is challenging due to the deep location and to the complex relationships between the tumor and the neurovascular structures. The objective is to present a petroclival tumor model simulating the distorted anatomy of a real petroclival lesion and propose its use to practice microsurgical removal while preserving neurovascular structures. Four embalmed cadaver heads were used in this study. An endoscopic endonasal transclival approach was used to access the dura in front of the trigeminal nerve; a pediatric Foley was inserted above the trigeminal nerve and was gradually inflated (one-balloon technique). If a larger tumor model was desired, an additional balloon was placed below the trigeminal nerve (two-balloon technique). A pre-mixed tumor polymer was injected into the petroclival space and allowed to harden to create an implanted tumor. A post-implant CT scan was done to evaluate the location and volume of the implanted artificial tumor. Tumors were subsequently excised via retrosigmoid and anterior petrosal approaches. Six petroclival tumors were successfully developed: three were small (9.41-10.36 ml) and three large (21.05-23.99 ml). During dissection, distorted anatomy created by the tumor model mimicked that of real surgery. We have established a petroclival tumor model with adjustable size which offers opportunities to study the distorted anatomy of the area and that is able to be used as a training tool to practice microsurgical removal of petroclival lesions. The practice dissection of this tumor model can be a bridge between a normal anatomic dissection and real surgery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10143-015-0683-6DOI Listing
April 2016

Central Nervous System Cancers, Version 1.2015.

J Natl Compr Canc Netw 2015 Oct;13(10):1191-202

From University of Alabama at Birmingham Comprehensive Cancer Center; City of Hope Comprehensive Cancer Center; The Ohio State University Comprehensive Cancer Center - James Cancer Hospital and Solove Research Institute; Yale Cancer Center/Smilow Cancer Hospital; The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins; The University of Texas MD Anderson Cancer Center; UCSF Helen Diller Family Comprehensive Cancer Center; University of Washington/Seattle Cancer Care Alliance; Roswell Park Cancer Institute; Duke Cancer Institute; UC San Diego Moores Cancer Center; University of Michigan Comprehensive Cancer Center; Memorial Sloan Kettering Cancer Center; St. Jude Children's Research Hospital/University of Tennessee Health Science Center; Massachusetts General Hospital Cancer Center; American Brain Tumor Association; Vanderbilt-Ingram Cancer Center; Mayo Clinic Cancer Center; Robert H. Lurie Comprehensive Cancer Center of Northwestern University; Stanford Cancer Institute; Fred & Pamela Buffet Cancer Center; Huntsman Cancer Institute at the University of Utah; Siteman Cancer Center at Barnes-Jewish Hospital and Washington University School of Medicine; Moffitt Cancer Center; Fox Chase Cancer Center; Dana-Farber/Brigham and Women's Cancer Center; National Comprehensive Cancer Network.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Central Nervous System (CNS) Cancers provide interdisciplinary recommendations for managing adult CNS cancers. Primary and metastatic brain tumors are a heterogeneous group of neoplasms with varied outcomes and management strategies. These NCCN Guidelines Insights summarize the NCCN CNS Cancers Panel's discussion and highlight notable changes in the 2015 update. This article outlines the data and provides insight into panel decisions regarding adjuvant radiation and chemotherapy treatment options for high-risk newly diagnosed low-grade gliomas and glioblastomas. Additionally, it describes the panel's assessment of new data and the ongoing debate regarding the use of alternating electric field therapy for high-grade gliomas.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.6004/jnccn.2015.0148DOI Listing
October 2015

Primary Meningeal Pleomorphic Xanthoastrocytoma With Anaplastic Features: A Report of 2 Cases, One With BRAF(V600E) Mutation and Clinical Response to the BRAF Inhibitor Dabrafenib.

J Neuropathol Exp Neurol 2015 Oct;74(10):960-9

From the Departments of Pathology (AU, CRP, CAK, WZ, NLL), Anatomy (CRP), Neurosurgery (KH, MA), and Neuroscience (NLL), and Division of Neuro-oncology (VKP), The Ohio State University; and Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital (CRP), Columbus Ohio; and Departments of Pathology (ONK, TGM, NLL) and Neurosurgery (JR), Henry Ford Hospital, Detroit, Michigan.

Primary meningeal gliomas are rare tumors composed of a heterogeneous group of neoplasms. We present 2 clinically aggressive cases of primary meningeal pleomorphic xanthoastrocytoma that clinically mimicked meningioma. One case presented in the posterior fossa of a 56-year-old woman; the other centered on the left operculum of a 35-year-old woman. These cases showed many of the classic features of pleomorphic xanthoastrocytoma, except that xanthomatous cells were rare and eosinophilic granular bodies were inconspicuous. Both cases exhibited high proliferative indices and superficially invaded the brain. One case harboring a BRAF mutation disseminated to the thecal sac and showed a clinical response to the targeted BRAF inhibitor dabrafenib. These cases seem to represent an unusual primarily extra-axial presentation of pleomorphic xanthoastrocytoma and may account for at least some of the previously reported cases of primary meningeal glioma and/or glial fibrillary acidic protein-immunoreactive meningioma variants. We suggest that BRAF mutation analysis be considered in all meningeal lesions showing atypical histologic or immunohistochemical profiles, particularly those exhibiting glial differentiation, as a diagnostic aid and possible indication for targeted therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/NEN.0000000000000240DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4777522PMC
October 2015

A differentially expressed set of microRNAs in cerebro-spinal fluid (CSF) can diagnose CNS malignancies.

Oncotarget 2015 Aug;6(25):20829-39

MVIMG, The Ohio State University, Columbus, OH, USA.

Central Nervous System malignancies often require stereotactic biopsy or biopsy for differential diagnosis, and for tumor staging and grading. Furthermore, stereotactic biopsy can be non-diagnostic or underestimate grading. Hence, there is a compelling need of new diagnostic biomarkers to avoid such invasive procedures. Several biological markers have been proposed, but they can only identify specific prognostic subtype of Central Nervous System tumors, and none of them has found a standardized clinical application.The aim of the study was to identify a Cerebro-Spinal Fluid microRNA signature that could differentiate among Central Nervous System malignancies.CSF total RNA of 34 neoplastic and of 14 non-diseased patients was processed by NanoString. Comparison among groups (Normal, Benign, Glioblastoma, Medulloblastoma, Metastasis and Lymphoma) lead to the identification of a microRNA profile that was further confirmed by RT-PCR and in situ hybridization.Hsa-miR-451, -711, 935, -223 and -125b were significantly differentially expressed among the above mentioned groups, allowing us to draw an hypothetical diagnostic chart for Central Nervous System malignancies.This is the first study to employ the NanoString technique for Cerebro-Spinal Fluid microRNA profiling. In this article, we demonstrated that Cerebro-Spinal Fluid microRNA profiling mirrors Central Nervous System physiologic or pathologic conditions. Although more cases need to be tested, we identified a diagnostic Cerebro-Spinal Fluid microRNA signature with good perspectives for future diagnostic clinical applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/oncotarget.4096DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4673232PMC
August 2015

Quantitative and qualitative analysis of the working area obtained by endoscope and microscope in pterional and orbitozigomatic approach to the basilar artery bifurcation using computed tomography based frameless stereotaxy: A cadaver study.

Asian J Neurosurg 2015 Apr-Jun;10(2):69-74

Department of Neurological Surgery, Dardinger Microneurosurgical Skull Base Laboratory, The Ohio State University Medical Center, Columbus, Ohio.

Objective: Basilar aneurisms are one of the most complex and challenging pathologies for neurosurgeons to treat. Endoscopy is a recently rediscovered neurosurgical technique that could lend itself well to overcome some of the vascular visualization challenges associated with this pathology. The purpose of this study was to quantify and compare the basilar artery (BA) bifurcation (tip of the basilar) working area afforded by the microscope and the endoscope using different approaches and image guidance.

Materials And Methods: We performed a total of 9 dissections, including pterional (PT) and orbitozygomatic (OZ) approaches bilaterally in five whole, fresh cadaver heads. We used computed tomography based image guidance for intraoperative navigation as well as for quantitative measurements. We estimated the working area of the tip of the basilar, using both a rigid endoscope and an operating microscope. Operability was qualitatively assessed by the senior authors.

Results: In microscopic exposure, the OZ approach provided greater working area (160 ± 34.3 mm(2)) compared to the PT approach (129.8 ± 37.6 mm(2)) (P > 0.05). The working area in both PT and OZ approaches using 0° and 30° endoscopes was larger than the one available using the microscope alone (P < 0.05). In the PT approach, both 0° and 30° endoscopes provided a working area greater than a microscopic OZ approach (P < 0.05) and an area comparable to the OZ endoscopic approach (P > 0.05).

Conclusion: Integration of endoscope and microscope in both PT and OZ approaches can provide significantly greater surgical exposure of the BA bifurcation compared to that afforded by the conventional approaches alone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4103/1793-5482.145064DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4421971PMC
May 2015

Image-guided, microsurgical topographic anatomy of the endolymphatic sac and vestibular aqueduct via a suboccipital retrosigmoid approach.

Neurosurg Rev 2015 Oct 25;38(4):715-21. Epub 2015 Apr 25.

Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery, Wexner Medical Center, The Ohio State University, N1025 Doan Hall, 410 West 10th Avenue, Columbus, OH, 43210, USA.

The endolymphatic sac (ES) and the vestibular aqueduct (VA) are often in the surgical field when posterior fossa lesions are targeted using retrosigmoid approaches. The purpose of this work is to validate neuronavigator accuracy in predicting VA location as well as to give guidelines to preserve the ES and VA. A retrosigmoid approach was performed bilaterally in six specimens in the semisitting position. Preoperatively, we registered in the CT scans the position of the VA genu (virtual genu). After the approach execution, ES and VA genu topographic relationships with evident posterolateral cranial base structures were measured using neuronavigation. Next, we exposed the VA genu: its position coincided with the virtual VA genu in all the specimens. On the average, the ES was 17.93 mm posterosuperolateral to the XI nerve in the jugular foramen, 12.26 mm posterolateral to the internal acoustic meatus, 20.13 mm anteromedial to the petro-sigmoid intersection at a point 13.30 mm inferior to the petrous ridge. The VA genu was located 7.23 mm posterolateral to the internal acoustic meatus, 18.11 mm superolateral to the XI nerve in the jugular foramen, 10.27 mm inferior to the petrous ridge, and 6.28 mm anterolateral to the endolymphatic ledge at a depth of 3.46 mm from the posterior pyramidal wall. Our study demonstrates that is possible to use neuronavigation to reliably predict the location of the VA genu. In addition, neuronavigation may be effectively used to create a topographical framework that may help maintaining the integrity of the ES/VA during retrosigmoid approaches.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10143-015-0634-2DOI Listing
October 2015

Maximizing the petroclival region exposure via a suboccipital retrosigmoid approach: where is the intrapetrous internal carotid artery?

Neurosurgery 2015 Jun;11 Suppl 2:329-36; discussion 336-7

*Dardinger Microneurosurgical Skull Base Laboratory, Department of Neurological Surgery and §Department of Radiology and Wright Center of Innovation in Biomedical Imaging, Wexner Medical Center, The Ohio State University, Columbus, Ohio; ‡Department of Neurosurgery, Umberto I General Hospital, Università Politecnica delle Marche, Ancona, Italy.

Background: Recent reports have validated the use of retrosigmoid approach extensions to deal with petroclival lesions.

Objective: To describe the topographic retrosigmoid anatomy of the intrapetrous internal carotid artery (IICA), providing guidelines for maximizing the petroclival region exposure via this route.

Methods: The IICA was exposed bilaterally in 6 specimens via a retrosigmoid approach in the semisitting position. Its topographic relationship with pertinent posterolateral cranial base landmarks was quantified with neuronavigation.

Results: Safe exposure of the IICA and the surrounding inframeatal/petroclival regions was accomplished in all specimens. On average, the IICA genu was 15.08 mm anterolateral to the XI nerve in the jugular foramen, 16.18 mm anteroinferolateral to the endolymphatic sac, and 10.63 mm anteroinferolateral to the internal acoustic meatus. On average, the IICA horizontal segment was 9.92 mm inferolateral to the Meckel cave, and its midpoint was 19.96 mm anterolateral to the XI nerve in the jugular foramen. The mean distance from the IICA genu to the cochlea was 1.96 mm. The genu and the midpoint of the horizontal segment of the IICA were exposed at a depth of approximately 14.50 mm from the posterior pyramidal wall with the use of different drilling angles (49.74° vs 39.54°, respectively).

Conclusion: Knowledge of the IICA general relationship with these landmarks (combined with a careful assessment of the preoperative imaging and with the use of intraoperative navigation and micro-Doppler) may help to enhance the inframeatal/petroclival region exposure via a retrosigmoid route, maximizing safe inframeatal and suprameatal petrous bone removal while minimizing neurovascular complications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1227/NEU.0000000000000749DOI Listing
June 2015

In vivo brain electrophoresis - a novel method for chemotherapy of CNS diseases.

Expert Opin Drug Deliv 2015 May 10;12(5):727-34. Epub 2015 Feb 10.

The Ohio State University Wexner Medical Center, Department of Neurological Surgery , N-1025 Doan Hall, 410 west 10th ave, Columbus, OH 43210 , USA +1 614 293 1970 ; +1 614 293 4024 ;

Objective: The blood-brain barrier (BBB) is a protective mechanism that does its job superbly. So much so, that hitherto, brain chemotherapy has been limited by it. In fact, very few agents are effective against brain disease due to the inherent difficulties of penetrating the BBB. We describe a novel, extremely focused method for delivering drugs to specific diseased areas. This innovative method directly delivers putative substances to the pathological area, bypassing the BBB. Treatment of brain diseases could be improved by targeted, controlled delivery of therapeutic substances to diseased cerebral areas. Our described novel method - in vivo electrophoresis - achieves this.

Methods: This technique was evaluated in beagles after craniotomy was performed and a custom-designed plate with electrodes inserted. The delivery of charged substances to selected areas with predictably guided movement was achieved via a created electrical field. Gadolinium, a compound unable to cross the BBB, was injected intracerebrally whereas an electrical field was created using the implanted electrodes surrounding the injection area. The electrical field-guided Gadolinium movement was evaluated using MRI.

Results: Gadolinium was moved predictably using the created electrical field without complications.

Conclusions: The experiment successfully demonstrated controlled movement of the substance. This technique can significantly change treatment of brain diseases because substances: i) may be moved in a controlled, predictable way - exponentially increasing therapeutic interactions with the target; and ii) no longer need to conform to constraints dictated by the BBB (molecular mass < 500 d; lipophilic), thereby increasing potential number of usable substances.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1517/17425247.2015.1014034DOI Listing
May 2015
-->