Dural Tears and Cerebrospinal Fluid Leak During and After the Middle Fossa Repair of Superior Canal Dehiscence Syndrome

Objective: To examine the incidence, predictors, and clinical impact of iatrogenic dural tears and cerebrospinal fluid (CSF) leaks during and after the middle cranial fossa (MCF) repair of superior canal dehiscence syndrome (SCDS). Study design: Case-control study. Setting: Tertiary referral center. Patients: Subjects with SCDS electing to undergo surgery. Intervention(s): MCF repair of SCD. Main outcome measures: Identification of intraoperative dural microtears and larger iatrogenic CSF leaks, as well as postoperative CSF leaks; analysis of predictive factors; and evaluation of symptomatology and audiometric outcomes. Results: Among 426 MCF repairs, larger iatrogenic intraoperative leaks requiring lumbar drain placement occurred in 4% (n=17) of cases, and clinically significant postoperative CSF leaks occurred in 2.1% (n=9). In addition, 76 cases of pinpoint dural microtears were observed intraoperatively, all of which were successfully repaired at the time of surgery. Older age (aOR: 1.05 per year, 95% CI: 1.02–1.07), systemic hypertension (aOR: 1.90, 95% CI: 1.09–3.31), and radiographic tegmen dehiscence (aOR: 2.14, 95% CI: 1.27–3.61) independently predicted leak risk. Compared with controls, cases with CSF leak had a mean increase of 14 operative minutes (adj. β 0.24h, 95% CI: 0.09–0.39), and a 0.8-day longer hospital stay (aIRR: 1.25, 95% CI: 1.10–1.43). Conclusion: Iatrogenic dural microtears with intraoperative CSF microleak are common (∼18%) but overwhelmingly minor and effectively repaired intraoperatively. Larger intraoperative leaks requiring lumbar drain occurred in 4% of cases, while clinically significant postoperative CSF leaks were rare (2.1%). Older age, systemic hypertension, and tegmen dehiscence are independently associated with increased leak risk, although the overall clinical impact was modest.