A Unique Iatrogenic Defect during Pituitary Surgery

Educational Objective: The endoscopic transsphenoidal approach has evolved into the preferred method for surgical access to pituitary tumors and other sellar lesions. Despite increasingly advanced techniques, cerebrospinal fluid (CSF) leak remains a common intraoperative occurrence that requires attention. In this paper, we describe a unique iatrogenic defect at the anterior most aspect of the sellar diaphragm. It occurs secondary to superior extension of the dural incision causing unintentional dissection of the diaphragm. This type of defect is important to identify because it produces an intraoperative CSF leak that is challenging to repair.

Methods: A retrospective analysis of all pituitary adenomas treated surgically at a tertiary referral institution over the past 5 years (2013–2017) was conducted. A total of 346 patients met the inclusion criteria.

Results: An anterior sellar diaphragmatic defect was identified in 14 (or 4%) of patients. An intraoperative leak was present in all cases. There were no postoperative leaks. Age, gender, BMI, tumor size, and type did not differ significantly between those patients with and without this defect. However, 9/14 (64%) of these defects were unable to be closed with a primary dural repair alone. Those patients with an anterior sellar diaphragmatic leak were significantly more likely to require the use of a nasoseptal flap as part of the multilayer reconstruction technique (p <  0.05).

Conclusion: Iatrogenic anterior sellar diaphragmatic defects located at the junction of the dura and diaphragm represent a distinct intraoperative consideration during endoscopic pituitary surgery. The resulting CSF leak is particularly challenging to repair due to its direct connection with the suprasellar cistern and difficulty in placement of an “inlay graft.” Successful repair can be achieved with proper positioning of a dural substitute, but these defects often require a multilayer reconstruction with the use of a nasoseptal flap in addition. This represents the first study to analyze the reconstructive outcomes of this unique type of defect.