Iatrogenic Cerebrospinal Fluid Leak in Endoscopic Sinus Surgery: Topographical Map and Influence of Skull Base Asymmetry.

BACKGROUND: Iatrogenic cerebrospinal fluid leak (iCSF-L) is a major complication of endonasal surgeries whose occurrence is always a potential adverse event due to anatomical variation/asymmetry of the skull base (SB). The aim of this manuscript is to provide a topographical map of iCSF-L and to investigate the role of SB asymmetry in iCSF-L occurrence. METHODS: In this retrospective study, the location of iCSF-L dural defect was studied and compared to patients affected by spontaneous and post-traumatic CSF-L. Considering only iCSF-L, after having collected the SB asymmetry data, the Keros, Gera, distance of the anterior ethmoidal artery from the SB, frontal sinus pneumatization, and Thailand-Malaysia-Singapore score classifications were compared to a control group of patients. RESULTS: A total of 153 CSF-Ls (103 spontaneous, 37 iatrogenic, and 13 traumatic) were included. A significant association was noted (p < 0.001) between the nature of the CSF-L and the areas involved. Considering iCSF-Ls, only the Gera classification was significantly different (p < 0.05) and the most reliable in predicting the risk of dural transgression (AUC = 0.719). CONCLUSIONS: ICSF-Ls present peculiar regional SB involvement with the cribriform plate, with the ethmoidal roof being the most involved. After having assessed the asymmetry of the SB, the Gera classification was the most reliable one.

Presentation, Management, and Hearing Outcomes of Labyrinthine Fistula Secondary to Cholesteatoma: A Systematic Review and Meta-analysis.

OBJECTIVE: The current study systematically reviewed the literature to compare auditory outcomes of patients treated for labyrinthine fistula (LF) based on characteristics of disease and surgical management. DATABASES REVIEWED: PubMed, Scopus, Web of Science. METHODS: Original series (at least five cases) published from 2000 reporting management and hearing results of LF secondary to cholesteatoma were included. Proportion and odds-ratio (OR) meta-analyses were conducted through inverse variance random-effects models based on logit transformation. RESULTS: The prevalence of LF is estimated to be 7% (95% confidence interval [CI], 5-9%). Fistulae involving the lateral semicircular canal (90%; 95% CI, 87-93%) and larger than 2 mm (53%; 95% CI, 43-64%) were common, whereas membranous involvement was less frequent (20%; 95% CI, 12-30%). Complete removal of the cholesteatoma matrix overlying the LF was mostly applied. Bone conduction (BC) preservation was frequently achieved (81%; 95% CI, 76-85%); new-onset postoperative anacusis was rarely reported (5%; 95% CI, 4-8%). A higher chance of BC preservation was associated with sparing the perilymphatic space (OR, 4.67; 95% CI, 1.26-17.37) or membranous labyrinth (OR, 4.56; 95% CI, 2.33-8.93), exclusive lateral semicircular canal involvement (OR, 3.52; 95% CI, 1.32-9.38), smaller size (<2 mm; OR, 3.03; 95% CI, 1.24-7.40), and intravenous steroid infusion (OR, 7.87; 95% CI, 2.34-26.42). CONCLUSION: LF occurs in a significant proportion of patients with cholesteatoma. In the past two decades, complete removal of the cholesteatoma matrix followed by immediate sealing has been favored, supported by the high proportion of BC preservation. Hearing preservation depends primarily on characteristics of the LF, and specific surgical strategies should be pursued. Intraoperative and postoperative intravenous steroid infusion is recommended.