Pituitary transposition techniques: surgical anatomy and technical nuances.

Abstract

Objective: The primary objective of this study was to elaborate on the surgical anatomy and technical nuances of pituitary transposition techniques and assess their clinical application, enhancing both the safety and efficacy of endonasal approaches to the retrosellar and interpeduncular regions.

Methods: Twenty-two colored silicone-injected specimens were dissected stepwise via an endoscopic endonasal approach. A comprehensive assessment of pituitary transposition techniques, including anatomical landmarks, surgical nuances, and transposition distances, was performed. Their clinical relevance was presented using illustrative cases.

Results: The following pituitary transposition techniques were established according to their relationship with the dual-layered sellar dura and the extent of pituitary gland mobilization: extradural (involves elevating the dura from the sellar floor, allowing limited access to the lower dorsum sellae and superior pituitary gland mobilization [mean vertical transposition distance ± SD of 2.4 ± 0.7 mm]); interdural transsellar (outer dural layer is incised at the sellar face and floor, improving access to the dorsum sellae and facilitating further superior pituitary gland mobilization [mean vertical transposition distances of 4.1 ± 0.8 mm at the midline and 4.9 ± 0.7 mm at the lateral aspect]); interdural transcavernous (outer dural layer is opened at the anterior wall of the cavernous sinus [CS] for superomedial pituitary gland mobilization with direct transcavernous access to the posterior clinoid process [mean vertical transposition distances of 3.6 ± 0.6 mm at the midline and 6.8 ± 0.7 mm at the lateral aspect, mean horizontal transposition distance of 3.8 ± 0.7 mm]); extended interdural transcavernous (interdural approach is extended into the clinoidal space by transecting the caroticoclinoid ligament, maximizing exposure for challenging posterior clinoidectomy [mean vertical transposition distances of 5.5 ± 0.9 mm at the midline and 8.7 ± 0.9 mm at the lateral aspect, mean horizontal transposition distance of 7.2 ± 0.8 mm]); intradural hemitransposition (involves opening both dural layers at the sellar face, dissecting the pituitary gland away from the medial wall of the CS on the selected side, and enabling ipsilateral paramedian exposure of the dorsum sellae and retrosellar and retroinfundibular regions); full intradural (pituitary gland is dissected away from the medial wall of the CS bilaterally, facilitating its horizontal and vertical mobilization and providing comprehensive access to the dorsum sellae and bilateral retrosellar and retroinfundibular regions; transection of the diaphragm enhances suprasellar access); and pituitary gland sacrifice (complete removal, offering unimpeded access to the retrosellar and retroinfundibular regions).

Conclusions: Seven pituitary transposition techniques based on dural opening, gland mobilization, and approach extent are described herein. Selecting the appropriate technique, guided by the affected anatomical regions, pathology type, and preoperative pituitary gland function, is crucial for optimal surgical outcomes.