Endoscopic Endonasal Resection of the Medial Wall of the Cavernous Sinus: Mayo Clinic Experience and Impact on Pituitary Surgery Outcomes

Introduction: Invasion of the medial wall of the cavernous sinus (CS) by pituitary tumors is a factor associated with persistence of disease and subtotal resection of these tumors. Resection of the medial wall of the CS is therefore an option for maximum resection of such tumors, however, there is concern with potential complications associated with this technique and at this time, limited data is available in the literature. The aim of this study is to present our experience with the application of selective resection of the medial wall of the cavernous sinus in endoscopic pituitary surgery.

Methods: Single center retrospective study evaluating patients that underwent endoscopic endonasal resection of pituitary adenomas and resection of the medial wall of the CS, between January 2022 and June 2023. Extent of resection, remission rates, complications and histopathological diagnosis were assessed.

Results: Out of a population of 120 pituitary surgeries, 21 cases were eligible for this study. 7 (33.3%) patients had nonfunctional adenomas, and 14 (66.6%) had functional adenomas, including 5 adrenocorticotropic hormone, 4 prolactin, 4 growth-hormone, 1 pluri-hormonal (GH and prolactin)-secreting tumors. Complete tumor resection, based on intraoperative impression and postoperative MRI, was achieved in all cases. At last follow-up, complete biochemical remission (using current criteria) was seen in 14 cases (100%) of functional adenomas. One case developed pulmonary embolism and another one sino-nasal infection postoperatively, 1 medial wall resection was aborted due to bleeding of inferior hypophyseal, 1 case was aborted due to ICA tortuosity, 1 case (Cushing’s) presented with recurrence 2 years after surgery. No fatalities, carotid injuries or cranial nerve palsies were reported.

Fig 1 The medial wall of the CS formed by the meningeal layer surrounds the pituitary and merges superiorly with the periosteal layer to form the sellar diaphragm. The origin of the Caroticoclinoid ligament (CCL) represents the anteromedial aspect of the CS roof.

Fig. 2 Incision of the dural periosteal layer between the pituitary gland medially and the left ICA laterally, just medial and inferior to the anterior genu of the ICA allows access to the CS. The meningeal layer of the dura mater forming the medial wall of the CS is kept medially with the gland.

Fig. 3 The medial mobilization of the medial wall of the CS with section of the CCL as well as coagulation of the IHA provides the necessary access to the posterior clinoid.

Conclusions: Resection of the medial wall of the cavernous sins, performed when there is potential tumor extension into the medial wall, is associated with high rates of disease control. It is particularly useful in cases of functioning but also has a role in nonfunctional adenomas adherent to the medial wall of the CS. Long term follow-up is necessary to evaluate the durability of these results.

Publication History

Article published online:
05 February 2024