title: The Inferolateral Transorbital Endoscopic Approach: A Preclinical Anatomic Study.
abstract: BACKGROUND
  In recent years, transorbital endoscopic approaches are increasing in popularity as they provide several corridors to reach lateral areas of the ventral skull base through the orbit. The aim of this study is to investigate the feasibility of the inferolateral transorbital endoscopic approach (ILTEA) by detailing the step-by-step dissection, anatomic landmarks, and target anatomic areas.
  
  
  METHODS
  Seven cadaveric specimens (14 sides) were dissected in the Laboratory of Endoscopic Anatomy of the University of Brescia. Step-by-step dissection of ILTEA was performed to identify the main anatomic landmarks and corridors. Skin incision, dural incision, and boundaries of craniectomy were measured. Neuronavigation was used to check landmarks, track boundaries of surgical volumes, and measure orbital dislocation.
  
  
  RESULTS
  The study on the 14 ILTEAs defined 1 anatomic area ("waterline door") that leads to 4 corridors: Meckel's cave corridor, carotid foramen corridor, petrous corridor, and transdural middle fossa corridor. Crucial anatomic landmarks were identified and analyzed. Orbital dislocation was <10 mm.
  
  
  CONCLUSIONS
  ILTEA provides the surgeon with a direct route to the region of the "waterline door," lateral areas of the ventral skull base, and middle cranial fossa. In addition, it allows an optimal view of the intracranial and extracranial portions of the maxillary and mandibular nerves. Further anatomic and clinical studies are needed to validate ILTEA in surgical practice.
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy. Electronic address: 1990marcoferrari@gmail.com.
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Schreiber
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Mattavelli
authors.affiliation: Unit of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Belotti
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Rampinelli
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Lancini
authors.affiliation: Unit of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Doglietto
authors.affiliation: Unit of Neurosurgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
authors.forename: Marco Maria
authors.initials: MM
authors.lastname: Fontanella
authors.affiliation: Section of Anatomy and Physiopathology, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
authors.forename: Manfred
authors.initials: M
authors.lastname: Tschabitscher
authors.affiliation: Section of Anatomy and Physiopathology, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
authors.forename: Luigi Fabrizio
authors.initials: LF
authors.lastname: Rodella
authors.affiliation: Unit of Otorhinolaryngology-Head and Neck Surgery, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Nicolai
mesh_terms: D002102:Cadaver; D056424:Decompressive Craniectomy; D062109:Dermatologic Surgical Procedures; D006801:Humans; D021621:Imaging, Three-Dimensional; D044583:Neuroendoscopy / Q000379:methods*; D038361:Neuronavigation; D009915:Orbit / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery; D019291:Skull Base / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000601:surgery*
keywords: Anatomy; Cavernous sinus; Endoscopy; Middle cranial fossa; Orbit; Posterior cranial fossa; Skull base; Trigeminal ganglion