The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Miguel Chuquilin - One of the best experts on this subject based on the ideXlab platform.

Peter A. Drew - One of the best experts on this subject based on the ideXlab platform.

Marco Ravanelli - One of the best experts on this subject based on the ideXlab platform.

  • quantitative anatomical comparison of transnasal and transcranial approaches to the Clivus
    Acta Neurochirurgica, 2020
    Co-Authors: Edoardo Agosti, Marco Ferrari, Davide Mattavelli, Francesco Belotti, Marco Ravanelli, Giorgio Saraceno, Jimmy Qiu, Barbara Buffoli, Elena Raffetti, Alberto Schreiber
    Abstract:

    The Clivus was defined as “no man’s land” in the early 1990s, but since then, multiple approaches have been described to access it. This study is aimed at quantitatively comparing endoscopic transnasal and microsurgical transcranial approaches to the Clivus in a preclinical setting, using a recently developed research method. Multiple approaches were performed in 5 head and neck specimens that underwent high-resolution computed tomography (CT): endoscopic transnasal (transclival, with hypophysiopexy and with far-medial extension), microsurgical anterolateral (supraorbital, mini-pterional, pterional, pterional transzygomatic, fronto-temporal-orbito-zygomatic), lateral (subtemporal and subtemporal transzygomatic), and posterolateral (retrosigmoid, far-lateral, retrolabyrinthine, translabyrinthine, and transcochlear). An optic neuronavigation system and dedicated software were used to quantify the working volume of each approach and calculate the exposure of different clival regions. Mixed linear models with random intersections were used for statistical analyses. Endoscopic transnasal approaches showed higher working volume and larger exposure compared with microsurgical transcranial approaches. Increased exposure of the upper Clivus was achieved by the transnasal endoscopic transclival approach with intradural hypophysiopexy. Anterolateral microsurgical transcranial approaches provided a direct route to the anterior surface of the posterior clinoid process. The transnasal endoscopic approach with far-medial extension ensured a statistically larger exposure of jugular tubercles as compared with other approaches. Presigmoid approaches provided a relatively limited exposure of the ipsilateral Clivus, which increased in proportion to their invasiveness. This is the first anatomical study that quantitatively compares in a holistic way exposure and working volumes offered by the most used modern approaches to the Clivus.

  • transnasal endoscopic and lateral approaches to the Clivus a quantitative anatomic study
    World Neurosurgery, 2018
    Co-Authors: Francesco Doglietto, Marco Ferrari, Davide Mattavelli, Francesco Belotti, Vittorio Rampinelli, Hussein Kheshaifati, Davide Lancini, Alberto Schreiber, Tommaso Sorrentino, Marco Ravanelli
    Abstract:

    Background Transnasal endoscopic approaches to the Clivus have been established recently. Comparative analyses with classic lateral approaches are limited. In this study, we compared transnasal endoscopic and lateral approaches to the Clivus, quantifying the exposure and working volume of each approach in the anatomy laboratory. Methods High-resolution computed tomography scans were performed on 5 injected specimens (10 sides). In each specimen, transnasal endoscopic approaches (i.e., paraseptal, transrostral, extended transrostral, transethmoidal, and extended transclival without and with intradural hypophysiopexy) and lateral approaches (i.e., retrosigmoid, far-lateral, presigmoid retrolabyrinthine and translabyrinthine) to the Clivus were performed. An optic neuronavigation system and dedicated software (ApproachViewer; Guided Therapeutics Program, University Health Network, Toronto, Ontario, Canada) were used to quantify the working volume and exposed clival area of each approach. Statistical evaluation was performed with the Kruskal–Wallis test and Steel–Dwass–Critchlow–Fligner post hoc test. Results Endoscopic transnasal transclival approaches showed higher working volume and larger clival exposure compared with lateral approaches. Incremental volumetric values were evident for transnasal approaches; presigmoid approaches provided less working volume than retrosigmoid approaches. A transnasal transclival approach with hypophysiopexy provided significant exposure of the upper Clivus (84.4%). The transrostral approach was the first transnasal approach providing satisfactory access to the midClivus (66%); retrosigmoid and far-lateral approaches provided exposure of approximately one half of the midClivus. The lower Clivus was optimally exposed with endoscopic transclival approaches (83%), whereas access to this region was limited with lateral approaches. Conclusions This quantitative anatomic study shows that endoscopic transnasal approaches to the Clivus provide a larger working volume and wider exposure of the Clivus compared with lateral approaches.

Aldo Cassol Stamm - One of the best experts on this subject based on the ideXlab platform.

  • the endoscopic endonasal approach for extradural and intradural Clivus lesions
    World Neurosurgery, 2014
    Co-Authors: Eduardo Vellutini, Leonardo Balsalobre, Diego Rodrigo Hermann, Aldo Cassol Stamm
    Abstract:

    Objective To report the use of the endoscopic transnasal transclival approach to treat tumors involving the Clivus region. Methods The clinical records of 38 patients with Clivus lesions were retrospectively reviewed to determine the surgical technique used. All patients were surgically treated using any of the options of the endoscopic transnasal transclival approach at the Sao Paulo Skull Base Center from 2000–2011. A transsphenoidal, transpterygoidal, retropharyngeal, or a combination of approaches was chosen based on the tumor topography. Results Chordomas were the most frequent tumor (26 of 38), followed by chondrosarcoma (2 of 38). Biopsy only was performed in 6 patients with metastasis to the Clivus, and 1 patient with fibrous dysplasia underwent a planned partial resection. Gross total resection (GTR) was achieved in 15 of 31 (48%) patients with indications for GTR. For centrally located tumors, GTR was achieved in 75% (15 of 20 patients). Fistula was the most frequent complication (6 of 31; 19%) but was much lower in the most recent series using the nasoseptal flap (1 of 16; 6%). Tumors with lateral extensions or with previous treatment had the worst results. The presence of intradural extension was not a limiting factor for GTR. Conclusion Endoscopic transnasal surgery is an alternative approach to treatment of Clivus lesions, and, in expert hands, this technique can obtain good results. Lateral extension and previous treatment were factors that could make the surgery more difficult. Intradural extension did not limit the radicality of the removal.

  • primary spontaneous cerebrospinal fluid leaks located at the Clivus
    Allergy�Rhinol (Providence), 2013
    Co-Authors: Thibaut Van Zele, Adriano T Kitice, Eduardo Vellutini, Leonardo Balsalobre, Aldo Cassol Stamm
    Abstract:

    Transclival meningoceles and primary spontaneous cerebrospinal fluid (CSF) leaks at the Clivus are extremely rare lesions and only few of them have been reported in the literature. We report here six cases of transclival primary spontaneous CSF leaks through the Clivus. A retrospective case study was performed. We reviewed six cases involving sinonasal CSF leaks located at the Clivus treated between 1997 and 2009. Presenting symptoms, duration of symptoms, defect size, site of defect, surgical approach and technique of defect closure, intraoperative complications, postoperative complications, and recurrences are discussed. All CSF leaks were located in the upper central part of the Clivus. two of six patients showed signs of increased intracranial pressure (ICP) including arachnoid pits and/or empty sella. For three patients a purely transnasal approach was used with multilayer reconstruction using a nonvascularized graft, and three patients underwent a transnasal transseptal approach with a multilayer reconstruction, with nasoseptal flap. No recurrences of CSF leaks at Clivus or other sites were observed to date with a mean follow-up of 10.3 years (range, 3–15 years). Spontaneous CSF rhinorrhea located at the Clivus is an extremely rare condition. To date, only eight cases have been described. Here, we report the largest group of six consecutive cases. Irrespective of the used reconstruction technique in all cases a 100% closure rate was achieved. However, identification of increased ICP is an essential aspect and this condition should be treated either medically or surgically.

Amin B Kassam - One of the best experts on this subject based on the ideXlab platform.

  • fractures of the Clivus a contemporary series in the computed tomography era
    Neurosurgery, 2009
    Co-Authors: Pawel G Ochalski, Richard M Spiro, Anthony Fabio, Amin B Kassam, David O Okonkwo
    Abstract:

    OBJECTIVE: We report the morbidity and mortality associated with fractures of the Clivus and discuss management approaches specific to this unique diagnostic entity. METHODS: We performed a boolean search of our electronic medical record database to identify patients with fractures of the Clivus that were diagnosed using computed tomography of the head. A retrospective imaging and chart analysis was completed to further characterize the fractures and to analyze outcomes. RESULTS: Between January 1999 and December 2007, 41 patients were identified with fractures of the Clivus. We found a 0.21 % overall incidence among all head-injured patients presenting to our institution and a 2.3% incidence among those patients with a cranial fracture. Ten of 41 patients (24.4%) died, and neurological and vascular complications associated with central cranial base fractures were observed in 19 of 41 patients (46%). Furthermore, associated cranial fractures remote from the central cranial base and associated intracranial hemorrhages were observed in 40 of 41 (97.6%) and 33 of 41 (80.5%) patients, respectively. In terms of outcomes, 26 of 41 patients (63.5%) had a Glasgow Coma Scale score of 12 or greater at the time of discharge from the hospital. CONCLUSION: We demonstrate a lower than previously reported mortality rate in patients with clival fractures. Nevertheless, as a result of location, fractures of the Clivus were frequently associated with a high rate of complications and neurological sequelae.

  • expanded endonasal approach fully endoscopic completely transnasal approach to the middle third of the Clivus petrous bone middle cranial fossa and infratemporal fossa
    Neurosurgical Focus, 2005
    Co-Authors: Amin B Kassam, Paul A Gardner, Carl H Snyderman, Arlan Mintz, Ricardo L Carrau
    Abstract:

    Object The middle third of the Clivus and the region around the petrous internal carotid artery (ICA) is a difficult area of the skull base in terms of access. This is a deep area rich with critical neurovascular structures, which is often host to typical skull base diseases. Expanded endoscopic endonasal approaches offer a potential option for accessing this difficult region. The objective of this paper was to establish the clinical feasibility of gaining access to the paraclival space in the region of the middle third of the Clivus, to provide a practical modular and clinically applicable classification, and to describe the relevant critical surgical anatomy for each module. Methods The anatomical organization of the region around the petrous ICA, cavernous sinus, and middle Clivus is presented, with approaches divided into zones. In an accompanying paper in this issue by Cavallo, et al., the anatomy of the pterygopalatine fossa is presented; this was observed through cadaveric dissection for which an e...

  • expanded endonasal approach the rostrocaudal axis part ii posterior clinoids to the foramen magnum
    Neurosurgical Focus, 2005
    Co-Authors: Amin B Kassam, Paul A Gardner, Carl H Snyderman, Arlan Mintz, Ricardo L Carrau
    Abstract:

    Object Transsphenoidal approaches have been used for a century for the resection of pituitary and other sellar tumors. Recently, however, the standard endonasal approach has been expanded to provide access to other parasellar lesions. With the addition of the endoscope, this expansion has significant potential for the resection of skull base lesions. Methods The anatomical landmarks and surgical techniques used in expanded (extended) endoscopic approaches to the Clivus and cervicomedullary junction are reviewed and presented, accompanied by case illustrations of each segment (or module) of approach. The caudal portion of the midline anterior skull base and the cervicomedullary junction is divided into modules of approach: the middle third of the Clivus, its lower third, and the cervicomedullary junction. Case illustrations of successful resections of lesions via each module of the approach are presented and discussed. Conclusions Endoscopic expanded endonasal approaches to caudally located midline anterio...