Endoscopic transnasal approach to the pituitary--operative technique and nuances.

BACKGROUND: The endoscopic transnasal approach is becoming the preferred minimally invasive approach to the pituitary region. We review the key anatomical landmarks, stepwise description of the surgical technique, technical variations, indications, limitations and important aspects of peri-operative management. TECHNIQUE: The procedure consists of nasal, sphenoidal and sella stages performed using a rigid fibre-optic endoscope. Tumour debulking is undertaken with low-profile ring curettes, suction and/or ultrasonic aspirator. At the end, the pituitary fossa floor is reconstructed in a graded fashion, depending on the extent of the CSF leak through the arachnoidal and dural defects. Important technical variations include the surgeon position relative to the patient, uni- versus binostril approach, two- versus four-handed technique, extent of resection of the middle turbinate and the type of repair of the sella floor. Post-operative management is influenced by the nature of the pathology, involvement of the optic apparatus and changes to the pituitary function. In selected cases, extension of the technique along the sagittal and coronal planes can allow access to the other pathologies in the anterior, middle and posterior skull bases (i.e. the so-called extended approach). CONCLUSION: The endoscopic approach is becoming the technique of choice for accessing the pituitary region, with reduced nasal trauma, improved access, visualisation and potentially better tumour resection compared to the microscopic technique. However, there is an operative learning curve and some pathologies are more easily approached by this technique than others.