Evaluation of CSF Leak Rate in Acoustic Neuroma Resection and Techniques of Internal Auditory Canal Reconstruction

Objective: To evaluate the incidence of cerebrospinal fluid (CSF) leak following acoustic neuroma resection. To compare CSF leak rates based on the various techniques for reconstruction of the internal auditory canal (IAC).

Study Design: Retrospective chart review.

Setting: Academic medical center.

Patients: A cohort of 1,200 patients with acoustic neuromas presented to our institution from 2005 to 2018. The 263 of these 1,200 patients who underwent surgical resection for management of their lesion were analyzed.

Intervention: Retrosigmoid and translabyrinthine approaches to acoustic neuroma resections. At our institution, IAC reconstruction was performed with bone wax and muscle plug or Norian hydroxyapatite bone cement from 2005 to 2013. Starting in 2014, a newer model of bone cement, Cranios hydroxyapatite, was used for reconstruction.

Main Outcome Measures: Rates of CSF leak were evaluated across different methods of IAC reconstruction. To our knowledge, no studies currently exist comparing leak rates with different types of bone cements used in IAC reconstruction.

Results: Twelve of the 263 patients analyzed experienced a postoperative CSF leak (4.6%). The total leak rate among patients who did not receive bone cement for reconstruction was 14.3%. All leaks occurred following a retrosigmoid approach. 6 of the 12 leaks occurred when no bone cement was used to reconstruct the IAC (50%), 5 leaks occurred with Norian hydroxyapatite bone cement (41.7%), and 1 leak occurred with Cranios hydroxyapatite bone cement (8.3%).

When compared with all other types of closure, Cranios had a significantly reduced rate of postoperative CSF leak (p <  0.005). The leak rate following Cranios versus Norian hydroxyapatites trended toward significance but did not achieve (p = 0.07). A translabyrinthine approach was strongly associated with a lower leak rate (p <  0.005). The size of the acoustic neuroma did not affect leak rate (p = 0.22).

Conclusion: Our CSF leak rate following acoustic neuroma resection confirms the low rates reported throughout the literature. We further characterize this finding by demonstrating reduced leak rates with a translabyrinthine approach and with IAC reconstruction using Cranios bone cement.