Fetal Bovine Collagen Grafts for Repair of Tegmen Defects and Encephaloceles Via Middle Cranial Fossa Approach

Abstract

To evaluate the use of commercially available allogenic dural graft materials made of fetal bovine collagen, we present an analysis of our case series with use of autologous and allogenic graft materials. Patients who underwent surgical repair of a tegmen tympani defect associated with ipsilateral conductive hearing loss and cerebrospinal fluid (CSF) otorrhea using a middle cranial fossa (MCF) approach from 2004 to 2018 at Loyola University Medical Center were included. Resolution of CSF otorrhea, audiologic outcomes, facial nerve preservation, and surgical complications was analyzed. Thirty-three patients with an average age of 55.3 years (range: 21-78, standard deviation [SD]: 12.9) and body mass index of 34.4 (range: 22-51, SD: 7.4) underwent an MCF repair of a tegmen and dural defect. All patients presented with CSF otorrhea and conductive hearing loss ipsilateral to the defect. Repairs were made with combinations of allograft and autograft in 17 cases, allograft only in 15 cases, and autograft only in 5 cases. Improvement in hearing was noted in 33 cases, and resolution of CSF otorrhea was noted in 36 cases; one patient required repeat surgery which resolved CSF otorrhea. Three patients had minor complications; all these were in the autograft group. The MCF approach coupled with the use of fetal bovine collagen grafts is a safe and viable method to repair tegmen tympani and associated dural defects with salutary outcomes and low morbidity.

A Comparison of Outcomes Using Combined Intra- and Extradural versus Extradural-Only Repair of Tegmen Defects

“…22 Patel et al reported outcomes with various repair strategies using an autograft, an allograft, or a combination of the two, with overall excellent outcomes pertaining to hearing improvement and resolution of CSF leak. 23 In both the combined ID/ED repair and ED-only repair patient cohorts, the majority of surgeries utilized autologous squamosal temporal bone from the craniotomy to cover the bony defects. However, there were important differences in the other allograft materials used for reconstruction between the two cohorts.…”

Middle Cranial Fossa Approach to Repair Tegmen Dehiscence Using Self-setting Calcium Phosphate Cement: A Retrospective Case Review

“…Hearing outcomes after MCF tegmen repair are excellent with no reported sensorineural hearing loss. Past studies report that the majority of patients have objective overall improvement in hearing; however, the underlying pathology is likely to affect hearing outcomes in 60 to 93% of cases (39)(40)(41).…”