Ethmoid-pterygo-sphenoidal endoscopic approach (EPSea)
Operations on the cavernous sinus (sinus cavernosus) have always been particularly difficult and demanding due to the great importance and high incidence of this area. The goals of the operation are to create safe access to the sinus, establish a histological diagnosis and, if possible, remove the tumor completely. The expanded field of vision thanks to the endoscope and the collaboration between neurosurgeons and ENT doctors have led to the development of new surgical techniques that provide an adequate image of the cavernous sinus and allow surgery to be performed within the surgical corridors of this area, at low risk.
These operating methods are used only for tumors of the soft tissues of the cavernous sinus without a tendency to infiltrate the vessel walls. There are two different operating methods: classic functional endoscopic pituitary surgery (FEPS) or ethmoid-pterygo-sphenoidal endoscopic approach (EPSea). The choice of access depends on the type and degree of damage to the cavernous sinus. If the lesion does not extend beyond the medial (inner) and posterior superior regions, then FEPS may be sufficient. If the tumor has invaded the anterior inferior and lateral regions of the cavernous sinus, EPSea is required. The EPSea approach provides a frontal view of the cavernous sinus and allows direct control of the medial and lateral areas of the cavernous sinus. The intervention is performed ethmoidal and through total sphenoethmoidectomy. This requires a wider opening. Resection of the medial part of the posterior wall of the maxillary sinus is performed. Partial resection of the pterygoid process (processus pterygoideus) is carried out taking into account the pneumatization of the lateral sphenoidal sinus. The bone located in front of the cavernous sinus is removed using a high-speed bur and a KERRISON nibbler. Except for a tumor that extends exclusively to the lateral part of the cavernous sinus, the dura mater is dissected in the sella turcica and gradually expands towards the tumor, from the medial to the lateral direction. Our experience has shown that the transnasal endoscopic approach allows safe and effective treatment of tumors with extension to the cavernous sinus due to improved visual perspective, thanks to which blind curettage can be avoided. FEPS is suitable for smaller tumors that do not extend beyond the medial (inner) and posterior superior regions. We use an expanded approach (EPSea) in cases with more extensive lesions of the lateral or anterior inferior regions of the cavernous sinus.
The low complication rate and advantages of endoscopic transnasal sinus surgery have led to a rethinking of the role of surgery in the severe pathology of pituitary adenomas with infiltration of the cavernous sinus.