Understanding the Etiology and Defining the Treatment Algorithm for Delayed Postoperative Cerebrospinal Fluid Leaks

Background: Postoperative cerebrospinal fluid leak (CSF) after expanded endonasal approaches can be a challenging problem to rectify. The risk of postoperative leak increases dependent on the size and location of the defect and when a leak occurs, it is often within the first week after surgery. Delayed postoperative CSF leak is an uncommon and largely unstudied entity. The objective of this study was to identify the etiology of delayed postoperative CSF leaks and understand the efficacy of reconstruction strategies utilized.

Methods: A retrospective chart analysis was performed of over 1,000 endonasal approaches performed by a single neurosurgeon from 2010 to 2018. A delayed postoperative CSF leak was defined as any leak manifested greater than 1 week after surgery.

Results: We identified 17 cases of delayed postoperative CSF leak of which 7 occurred greater than 4 weeks after surgery (4 of these had a history of proton beam) ([Fig. 1]). The most common pathology included pituitary adenoma with suprasellar extension, clival chordoma, and meningioma. The most common initial reconstruction consisted of Duragen inlay/gasket seal (82% of patients) with a vascularized local flap (76.5% of patients). Postoperative presenting patient symptoms for CSF leak included rhinorrhea (82.4% of patients), headache (41.2% of patients), and meningitis (23.5% of patients) ([Table 1]). Imaging was performed on 12 patients prior to revision surgery of which 7 demonstrated pneumocephalus. The most common identifiable cause of delayed postoperative CSF leak included nasoseptal flap dehiscence (17.6%), a provoked event such as emesis, sneezing, or fall (17.6%), a necrotic local flap (11.8%), displacement of local flap (11.8%), and inappropriate folded healing of the local flap (11.8%) ([Table 1]).

The secondary reconstructive approaches utilized included fortification of the previous reconstruction with a fat graft (29.4% of patients), repair with Duragen fortified with a fat graft (23.5% of patients), repositioning of the previous flap (11.8% of patients), and repair with a new local flap (11.8% of patients). Diamox was used in 23.5% of patients. A lumbar or ventricular drain or shunt was used in 17.6% of patients. Of the 17 patients with a CSF leak repair, 29.4% required an additional CSF leak repair.

Conclusion: Delayed postoperative CSF leak after expanded endonasal approaches is rare and in our analysis occurred in less than 2% of cases. Here we identify the most common initial patient presenting symptoms, etiology of the delayed postoperative leak, reconstructive strategies utilized, and propose a treatment algorithm ([Fig. 2]). Our results suggest that one must remain vigilant for delayed postoperative CSF leak, which likely result from multifactorial causes including technical failure, elevated intraventricular pressure, and a history of adjuvant therapy. Many of these leaks appear amenable to treatment with fortification of the initial repair with an abdominal fat graft ± Duragen.

No conflict of interest has been declared by the author(s).