Hydroxyapatite Use in Repair of Lateral Skull Base CSF Leaks Via Transmastoid Approach: When Does It Work?

Abstract

Objective The objective of this study is to evaluate the efficacy and outcomes of using a transmastoid approach with hydroxyapatite cement to repair lateral skull base cerebrospinal fluid (CSF) leaks. Study Design Retrospective cohort study. Setting Tertiary-level care hospital. Patients Surgical patients 18 years or older between 2013 and 2022 with spontaneous CSF leak. Interventions Trans-mastoid approach for skull base repair using hydroxyapatite cement. Main Outcome Measures Failure rate of repair; location and size of defect, patient demographic factors. Results Of the 60 total defects (55 patients, 5 bilateral repairs) that underwent CSF leak repair using hydroxyapatite cement, the success rate was 91.66% (55 successful repairs). The average defect size in unsuccessful repairs was 1.15 cm compared with 0.71 cm for successful repairs. In addition, 80% (4/5) of the failed repairs were in the tegmen tympani region. Higher failure rate was noted in women (3/5) and in former smokers (4/5). Average time to recurrent symptoms was 1.75 years in the failed repair cohort. Of the patients with failed repairs, 4/5 were prescribed acetazolamide before their second procedure with successful second repair. In addition, five patients experienced postoperative headaches, three (5.4%) of whom required placement of VP shunts to relieve increased intracranial pressure. Two patients (3.6%) had complications of either infection or hearing loss. Conclusions Transmastoid approach utilizing hydroxyapatite is a successful approach for CSF leak repair, with a low complication and failure rate. Women, prior smoking history, and larger defects in the tegmen tympani region may need alternative materials or approach for repair. Long follow-up is warranted as recurrence of symptoms might be delayed. In cases of benign intracranial hypertension, adjuvant treatment with either acetazolamide or VP shunt placement may prevent failures.

The Safety and Efficacy of Hydroxyapatite Repair of Cholesteatoma Skull Base Defects

“… 5 , 6 , 7 Our research group continued to explore this question and investigated patient characteristics that make for idea candidates for hydroxyapatite repair. 8 …”

“…[5][6][7] Our research group continued to explore this question and investigated patient characteristics that make for idea candidates for hydroxyapatite repair. 8 Recent studies have shown that hydroxyapatite is a safe and effective material for this purpose and can be used in lieu of autologous materials, with postoperative complication rates ranging from 0% to 8%. 9,10 Utilization of hydroxyapatite in cases with cholesteatoma, has only been described as a material employed for mastoid obliteration in mastoidectomy surgery.…”

“…Kveton and colleagues were one of the first to investigate hydroxyapatite and its utility in to repair CSF leaks in a variety of pathological settings 5‐7 . Our research group continued to explore this question and investigated patient characteristics that make for idea candidates for hydroxyapatite repair 8 …”