The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Jeffrey A. Fearon - One of the best experts on this subject based on the ideXlab platform.
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Rigid fixation of the calvaria in craniosynostosis without using "rigid" fixation.
Plastic and reconstructive surgery, 2003Co-Authors: Jeffrey A. FearonAbstract:Early observations of intracranial translocation of metal wires, plates, and screws used for infant Skull Surgery have led some surgeons to investigate alternative forms of fixation. The purpose of this study was to review a series of infants and children in whom absorbable suture fixation was used as the sole method of fixation in cranial vault remodeling. Standard osteotomies were successfully modified to permit the use of this less rigid form of Fixation. Over a 6-year period, 142 cranial vault procedures were performed, primarily for craniosynostosis, using only absorbable sutures (2-0 polydioxanone). Patients who did not have absorbable suture fixation, or who had a combination of absorbable sutures with another form of fixation, were excluded from this review. Records were reviewed for results (assessed by both the treating surgeon and an independent anthropologist) and for complications. The average age of patients was 2 years, 7 months (range, 1 month to 16 years). The clinical results were judged as follows: grade I (excellent), 49 percent; grade II (minor imperfections), 48 percent; glade III (small surgical procedure needed), 2 percent; and grade IV (complete recuperation required), 1 percent. Anthropologic results were similarly distributed: excellent, 36 percent; good, 56 percent; fair, 8 percent; and poor, 0 percent. Those 3 to 8 percent of patients who were found to have the poorest results were all noted to have syndromes, and it appeared that an inherent lack of growth was the primary basis for the low score. There were no deaths or major complications in this series of patients. The smaller complications identified were infections [four cases (2.8 percent)] and transient cerebrospinal fluid leak [two cases (1.4 percent) ]. The most important factor in determining whether absorbable suture fixation was sufficient was the size of a preexisting calvarial defect. Although concerns have been raised about a possible link between absorbable suture fixation and subsequent poor reossification, no such association was noted in this review. The primary disadvantage of using absorbable sutures was the lack of rigidity provided. Advantages included lower costs, speed of application, and the absence of observed intracranial translocation. In conclusion, the use of absorbable suture fixation (with modifications in osteotomy design) was associated with both acceptable aesthetic outcomes and low complication rates. Craniofacial surgeons may wish to consider the use of absorbable sutures as another option for bone fixation in treatment of craniosynostosis.
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A magnetic resonance imaging investigation of potential subclinical complications after in situ cranial bone graft harvest.
Plastic and reconstructive surgery, 2000Co-Authors: Jeffrey A. FearonAbstract:The in situ harvest of cranial bone grafts, when assessed by clinical observation, has been shown to be a safe procedure when performed by experienced surgeons. However, might there be adverse sequelae from bone graft harvest that are not severe enough to produce observable changes and thus are missed by studies that rely on clinical outcomes? This study was designed to determine the incidence of “clinically silent” complications following routine bone graft harvest, such as punctate intracranial bleeding and cerebral contusions. This prospective clinical study included 20 patients. All patients had in situ cranial bone graft harvest performed by a single surgeon and underwent postharvest magnetic resonance imaging within 24 hours. Coronal computed tomographic scans were found to be the most helpful in the preoperative determination of donor sites. The average area of bone graft harvest was just under 14 cm2 (range, 3 to 30 cm2). No patients who had not previously undergone Skull Surgery were noted to have full-thickness breaches. Three patients identified with full-thickness breaches at Surgery had harvest sites located in areas in which a previous craniotomy had occurred, suggesting that extreme care be used when harvesting bone from this subset of patients. All 20 postoperative magnetic resonance scans were reviewed by a neuroradiologist and determined to be completely normal. In conclusion, not only is in situ cranial bone graft harvest a safe procedure as assessed by clinical outcomes, but no subclinical complications were identified by postoperative magnetic resonance imaging. (Plast. Reconstr. Surg. 105: 1935, 2000.)
T. Forcht Dagi - One of the best experts on this subject based on the ideXlab platform.
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The history of Skull base Surgery
Neurosurgical focus, 2012Co-Authors: Charles J. Prestigiacomo, T. Forcht DagiAbstract:NeuroSurgery is of great interest to historians of medicine and technology because it is relatively young, because it developed in an era of journals and publications, because lines and traditions of training and mentorship are relatively clear, and because the technologies that enabled the evolution of the profession and acted as inflection points in the emergence of certain surgical approaches and procedures are at once well documented and remarkably unambiguous. To the extent that is the case for neuroSurgery as a whole, it is even more so for Surgery of the Skull base. To trace the history of Skull base Surgery along its full expanse is to begin with Horsley and pituitary tumors (unless one wants to start even earlier with the treatment of trigeminal neuralgia); to move to Cushing’s work in the same arena (but also that of many others as well); to emphasize the impact of microsurgical techniques and new imaging modalities; to outline once radically innovative, but now widely practiced anatomical approaches to the Skull base; to emphasize the importance of team approaches; to discuss emerging therapeutic strategy as well as instrumentation and techniques; to acknowledge the importance of advances in neuroanesthesia and the medical and perioperative care of the neurosurgical patient; and to recognize the contributions of the many individuals who, over the past 25 years, have added to and furthered the field in these and other ways. It is not hard to point to leading individuals and important techniques. It is perhaps more difficult to frame them in a meaningful historical perspective because the work has occurred relatively recently, in the time frame historians call “near history.” Difficulties arise from both an evaluative and a nosological standpoint. For example, from an evaluative standpoint, how does one stratify the relative importance of corticosteroids, osmotic diuretics, and CSF drainage techniques and technologies in the control of intracranial pressure and the facilitation of exposure for base of Skull Surgery? How does one think about the idea of hybrid Surgery and stereotactic radiation? What will be the long-term view of anatomical approaches to giant basilar aneurysms in the light of endovascular Surgery? Have we reached a tipping point in the management of vestibular schwannomas, given the availability of and the outcomes associated with stereotactic radioSurgery? From a nosological standpoint, should we think about base of Skull Surgery in terms of anatomical approaches? One textbook that does just that starts with subfrontal approaches and then moves around the calvaria and down to the petrous and temporal region in a Cook’s tour of exposure, in the tradition of Henry’s Extensile Exposure and comparable surgical classics.1,6 Other publications have explored a set of technologies.5,7,10 Another focuses on the contribution of great men.9 Many surgeons have written about specific particular pathologies at the Skull base.2,8,11 It is likely that the next generation of essays on this subject will reflect the results of molecular diagnostics, genomics, and sophisticate outcome studies as well as currently emerging technologies (such as robotics and heavy particle radiation), and continued innovation in surgical techniques. This issue of Neurosurgical Focus contains a series of essays that discuss various elements of the history of Skull base Surgery. Lopez-Serna, Elhadi, and Thakur and Introduction
Maurizio Bignami - One of the best experts on this subject based on the ideXlab platform.
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Temporoparietal Fascia Flap Endonasal Transposition in Skull Base Reconstruction: Surgical Technique.
World neurosurgery, 2020Co-Authors: Alberto Daniele Arosio, Elisa Coden, Apostolos Karligkiotis, Luca Volpi, Gerardo Petruzzi, Raul Pellini, Paolo Battaglia, Paolo Castelnuovo, Maurizio BignamiAbstract:Reconstruction of wide Skull base defects resulting from multimodal treatment of cranial base malignancies are challenging. 1 Endonasal pedicled flaps (e.g., Hadad-Bassagusteguy flap) 1 , 2 are generally the first choice; however, inadequacy for the size and location of the defect or their unavailability are common occurrences in salvage reconstructions, and prior irradiation is an additional unfavorable condition for local flap viability. The temporoparietal fascia flap (TPFF) 3 is a regional flap vascularized by the superficial temporal artery, which is able to survive and integrate even in postirradiated areas. Its properties, such as thinness, pliability, foldability, and the long pedicle, make it a versatile flap for reconstruction of various defects of the Skull base, both in adults 3 , 4 , 5 , 6 , 7 and children. 8 In lateral Skull Surgery, TPFF proved to be effective in patients at higher risk of cerebrospinal fluid leak, 7 whereas its transposition into the nasal cavity through a temporal-infratemporal tunnel has been widely reported to repair defects of the ventral Skull base. 3 , 4 , 5 , 6 It represents a safe and effective technique with minimal additional morbidity (potential alopecia or scalp necrosis). 4 , 5 A recently described modification of this technique supports TPFF transposition via a supraorbital epidural corridor to reach the anterior Skull base, especially for large defects with supraorbital extension. 6 The present video ( Video 1 ) shows the step-by-step TPFF harvesting and endonasal transposition via a temporal-infratemporal tunnel to repair a wide middle cranial fossa defect resulting from osteoradionecrosis after endoscopic resection and heavy-particle radiation therapy for sinonasal adenoid-cystic carcinoma. At 6-months follow-up, optimal healing without complications was observed.
Charles J. Prestigiacomo - One of the best experts on this subject based on the ideXlab platform.
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The history of Skull base Surgery
Neurosurgical focus, 2012Co-Authors: Charles J. Prestigiacomo, T. Forcht DagiAbstract:NeuroSurgery is of great interest to historians of medicine and technology because it is relatively young, because it developed in an era of journals and publications, because lines and traditions of training and mentorship are relatively clear, and because the technologies that enabled the evolution of the profession and acted as inflection points in the emergence of certain surgical approaches and procedures are at once well documented and remarkably unambiguous. To the extent that is the case for neuroSurgery as a whole, it is even more so for Surgery of the Skull base. To trace the history of Skull base Surgery along its full expanse is to begin with Horsley and pituitary tumors (unless one wants to start even earlier with the treatment of trigeminal neuralgia); to move to Cushing’s work in the same arena (but also that of many others as well); to emphasize the impact of microsurgical techniques and new imaging modalities; to outline once radically innovative, but now widely practiced anatomical approaches to the Skull base; to emphasize the importance of team approaches; to discuss emerging therapeutic strategy as well as instrumentation and techniques; to acknowledge the importance of advances in neuroanesthesia and the medical and perioperative care of the neurosurgical patient; and to recognize the contributions of the many individuals who, over the past 25 years, have added to and furthered the field in these and other ways. It is not hard to point to leading individuals and important techniques. It is perhaps more difficult to frame them in a meaningful historical perspective because the work has occurred relatively recently, in the time frame historians call “near history.” Difficulties arise from both an evaluative and a nosological standpoint. For example, from an evaluative standpoint, how does one stratify the relative importance of corticosteroids, osmotic diuretics, and CSF drainage techniques and technologies in the control of intracranial pressure and the facilitation of exposure for base of Skull Surgery? How does one think about the idea of hybrid Surgery and stereotactic radiation? What will be the long-term view of anatomical approaches to giant basilar aneurysms in the light of endovascular Surgery? Have we reached a tipping point in the management of vestibular schwannomas, given the availability of and the outcomes associated with stereotactic radioSurgery? From a nosological standpoint, should we think about base of Skull Surgery in terms of anatomical approaches? One textbook that does just that starts with subfrontal approaches and then moves around the calvaria and down to the petrous and temporal region in a Cook’s tour of exposure, in the tradition of Henry’s Extensile Exposure and comparable surgical classics.1,6 Other publications have explored a set of technologies.5,7,10 Another focuses on the contribution of great men.9 Many surgeons have written about specific particular pathologies at the Skull base.2,8,11 It is likely that the next generation of essays on this subject will reflect the results of molecular diagnostics, genomics, and sophisticate outcome studies as well as currently emerging technologies (such as robotics and heavy particle radiation), and continued innovation in surgical techniques. This issue of Neurosurgical Focus contains a series of essays that discuss various elements of the history of Skull base Surgery. Lopez-Serna, Elhadi, and Thakur and Introduction
Gabriel Montaldo - One of the best experts on this subject based on the ideXlab platform.
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Chronic assessment of cerebral hemodynamics during rat forepaw electrical stimulation using functional ultrasound imaging.
NeuroImage, 2014Co-Authors: Alan Urban, Emilie Mace, Clément Brunner, Marc Heidmann, Jean Rossier, Gabriel MontaldoAbstract:Abstract Functional ultrasound imaging is a method recently developed to assess brain activity via hemodynamics in rodents. Doppler ultrasound signals allow the measurement of cerebral blood volume (CBV) and red blood cells' (RBCs') velocity in small vessels. However, this technique originally requires performing a large craniotomy that limits its use to acute experiments only. Moreover, a detailed description of the hemodynamic changes that underlie functional ultrasound imaging has not been described but is essential for a better interpretation of neuroimaging data. To overcome the limitation of the craniotomy, we developed a dedicated thinned Skull Surgery for chronic imaging. This procedure did not induce brain inflammation nor neuronal death as confirmed by immunostaining. We successfully acquired both high-resolution images of the microvasculature and functional movies of the brain hemodynamics on the same animal at 0, 2, and 7 days without loss of quality. Then, we investigated the spatiotemporal evolution of the CBV hemodynamic response function (HRF) in response to sensory-evoked electrical stimulus (1 mA) ranging from 1 (200 μs) to 25 pulses (5 s). Our results indicate that CBV HRF parameters such as the peak amplitude, the time to peak, the full width at half-maximum and the spatial extent of the activated area increase with stimulus duration. Functional ultrasound imaging was sensitive enough to detect hemodynamic responses evoked by only a single pulse stimulus. We also observed that the RBC velocity during activation could be separated in two distinct speed ranges with the fastest velocities located in the upper part of the cortex and slower velocities in deeper layers. For the first time, functional ultrasound imaging demonstrates its potential to image brain activity chronically in small animals and offers new insights into the spatiotemporal evolution of cerebral hemodynamics.