2025 Proffered Presentations
S296: EFFICACY OF SURGICAL MANAGEMENT FOR SPONTANEOUS MIDDLE CRANIAL FOSSA CSF LEAKS: A SYSTEMATIC REVIEW WITH META-ANALYSES
Jordan M Rasmussen; Daniel L Surdell; Geoffrey C Casazza; Anne K Maxwell; Cynthia M Schmidt; Harlan R Sayles; Mithun G Sattur; University of Nebraska Medical Center
Background: Spontaneous cerebrospinal fluid (CSF) leaks and/or encephaloceles result from bone-dura defects of the middle cranial fossa (MCF) floor. They are treated with surgical repair via transmastoid, transcranial, or combined approaches. There is increasing recognition of the role of elevated body mass index (BMI), obstructive sleep apnea (OSA) and idiopathic intracranial hypertension (IIH). It is important to ascertain contemporary post-operative recurrence rates in order to devise treatment algorithms that potentially incorporate these contributors. This study aims to comprehensively study recurrence rate and factors important for spontaneous MCF leak repair in published literature.
Methods: Systematic review using PRISMA guidelines was conducted using EMBASE, MEDLINE, Cochrane Library, and Scopus databases to identify studies reporting adult patients having undergone surgical management for middle cranial fossa defects with CSF leak/encephalocele of spontaneous origin. Inclusion criteria were studies that documented postoperative recurrence following MCF repair by transmastoid, transcranial, or combined approaches. Exclusion criteria were the absence of recurrence data, non-spontaneous origin of leaks, or leaks occurring in a pediatric population. Data were collected on patient characteristics, surgical approach, CSF leak recurrence, and adjuvant therapy. Statistical analyses included descriptive assessments and proportional meta-analyses using a restricted maximum likelihood model.
Results: 55 studies met inclusion criteria and were included for analysis, providing a total of 984 patients and 1035 ears. Patients were predominantly female (60.8%) and exhibited a tendency towards obesity, with a mean BMI of 35.89 kg/m² (range 23.0-43.2 kg/m²). Mean follow-up duration was 22.6 months (35 studies, range 3-74.4 months). The total rate of CSF leak recurrence across all patients was 6.81% (67/984). Proportional meta-analysis using a random-effects model yielded an estimated average recurrence rate of 5.92% (95% CI [0.042, 0.077]). 42 studies reported recurrence data with respect to a given surgical approach. Predicted recurrence rate was 2.8% for transcranial approach, 10.5% for transmastoid (TM) approach, and 10.2% for a combined (TM/MCF) approach. The average length of time until recurrence was 19.3 months (11 studies, range 0.5-48 months). A greater estimated recurrence rate was noted for high mean BMI (above 35.94 kg/m², 6.68%) compared to low mean BMI (3.35%) between studies, although not to a level of statistical significance. Studies pre-2013 had a lower estimated recurrence rate (4.78%) than studies post-2013 (6.33%), though not to a level of statistical significance. 68.9% (29 papers) of patients had encephalocele. Post-operative CSF leak persistence (10 studies) occurred in 8.3% of patients. Where data was available, the prevalence rates of IIH and OSA among these patients was 18.7% and 45.7%, respectively. Opening pressure (OP) was obtained from a total of 118 patients across 8 studies. Mean OP across these studies was 24.78 cm H2O (range = 18.7-51.66). 36.8% of patients had their intracranial pressure managed with acetazolamide, 41.0% received a lumbar drain, while 6.2% of patients underwent ventriculoperitoneal shunting.
Conclusion: Recurrence rate following repair for spontaneous middle fossa defects is relatively low. It has largely remained similar despite recognition of associated modifiable factors, management of which is heterogenous. Treatment algorithms could incorporate more standardized management of modifiable factors.