Article
The direct medial and lateral extended transnasal endoscopic exposure for the sphenoid sinus and central skull base – an anatomical study
Search Medline for
Authors
Published: | September 16, 2010 |
---|
Outline
Text
Objective: Endoscopic techniques offer several advantages in transnasal surgery including visually best-controlled surgical manipulation without using the nasal speculum. According to significant benefits, endoscopy improves to the gold standard in modern transnasal surgery. Goal of this study was to compare the direct medial and extended lateral endoscopic approach to the sphenoid sinus and central skull base.
Methods: The direct medial approach allows a quick entering of the sphenoid sinus. After gently mobilisation of the middle and superior turbinates, the anterior wall of the sphenoid sinus is opened using diamond drill or Kerrisone punches. The septal branch of the sphenopalatine artery is occluded in most cases. The lateral approach corresponds to an extended exposure of the sphenoid sinus. For this reason, the uncinate process and bulla ethmoidalis are removed, approaching the posterior maxillary sinus and anterior aspect of the pterygopalatine fossa. After partial ethmoidectomy the middle turbinate can be extensively lateralised and the sphenoid sinus can be entered through its anterior wall. In this way, a wide exposure can be created without injury of the sensitive middle turbinate and sphenoethmoidal recess.
Results: The direct medial method offers safe and time-consuming approach of the sphenoid sinus and is suitable for surgical treatment of intrasellar tumors. However, dissection in the lateral aspect of the sphenoid sinus near to the optocarotid recess, carotid prominence and pterygoid canal can become limited. For this reason, treating large tumors with cavernous sinus invasion, the lateral extended approach should be recommended, thus allowing wide exposure and free manipulation. Additional benefit is protection of the sphenopalatine artery, allowing creation of a vascularised septal flap if necessary.
Conclusions: Endoscopic visualization offers extended viewing angle, increased light intensity and the clear representation of patho-anatomical details in transnasal surgery. The direct medial approach presents a suitable approach for intrasellar lesions. For treatment of large tumors with cavernous sinus invasion the lateral extended approach is suitable.