Timing of Postoperative CSF Leak after Endoscopic Skull Base Surgery in Patients with Obstructive Sleep Apnea.

Background There is little data regarding postoperative outcomes of patients with obstructive sleep apnea (OSA) undergoing skull base surgery. The purpose of this study is to determine an association between risk factors and proximity of cerebrospinal fluid (CSF) leak to surgery in patients with OSA undergoing endoscopic skull base surgery. Methods A retrospective review of neurosurgical inpatients, with and without OSA, at a tertiary care institution from 2002 to 2015 that experienced a postoperative CSF leak after undergoing endoscopic skull base surgery. Results Forty patients met inclusion criteria, 12 (30%) with OSA. OSA patients had significantly higher body mass index (BMI; median 39.4 vs. 31.7, p < 0.01) and were more likely to have diabetes (41.7 vs. 10.7%, p = 0.04) than non-OSA patients; otherwise there were no significant differences in clinical comorbidities. No patients restarted positive pressure ventilation (PPV) in the inpatient setting. The type of repair was not a significant predictor of the time from surgery to leak. Patients with OSA experienced postoperative CSF leak 49% sooner than non-OSA patients (Hazard Ratio 1.49, median 2 vs. 6 days, log-rank p = 0.20). Conclusion Patients with OSA trended toward leaking earlier than those without OSA, and no OSA patients repaired with a nasoseptal flap (NSF) had a leak after postoperative day 5. Due to a small sample size this trend did not reach significance. Future studies will help to determine the appropriate timing for restarting PPV in this high risk population. This is important given PPV's significant benefit to the patient's overall health and its ability to lower intracranial pressure.

Evaluation of tyrosine receptor kinases in the interactions of head and neck squamous cell carcinoma cells and fibroblasts.

OBJECTIVE: Despite treatment advancements, disease-free survival of head and neck squamous cell carcinoma (HNSCC) has not significantly improved. This may be a result of tumor-fibroblasts interactions providing protective pathways for oncogenic cells to resist therapy. Further understanding of these relationships in HNSCC may improve effectiveness of targeted therapies. In this article, we investigated the role of several receptor tyrosine kinases (RTKs) in the interactions between HNSCC cells and supporting cells (fibroblasts). MATERIALS AND METHODS: HNSCC cell lines and human tumor samples were evaluated for FGFR1/2/3, and PDGF-beta expression levels. Cell lines (FADU, SCC1, OSC19, Cal27, SCC22A) were treated with a range of physiological concentrations of dovitinib and assessed for proliferation, cytotoxicity, and apoptosis. Mice bearing HNSCC xenografts were treated with dovitinib (20 mg/kg). RESULTS: Evaluation of HNSCC tumor specimens, cell lines and fibroblasts found variable expression of multiple RTKs (fibroblasts growth factor receptor, platelet derived growth factor receptor and vascular endothelial growth factor receptor) and their ligands, supporting previous theories of paracrine and autocrine signaling within the microenvironment. In a dose-dependent fashion, RTK inhibition reduced proliferation of HNSCC cell lines and fibroblast in vitro. When HNSCC cells were cocultured with fibroblasts, RTK inhibition resulted in a smaller reduction in the proliferation relative to untreated conditions. In vivo, RTK inhibition resulted in significant tumor regression and growth inhibition (p<0.05) and reduced the incidence of regional lymph node metastasis. CONCLUSION: Effective treatment of HNSCC, therefore, may require inhibition of multiple RTKs in order to adequately inhibit the microenvironment's various signaling pathways.