Surgical Implications of the Anteriorly Displaced Segments of the Anterior Cerebral Artery in the Management of Frontoethmoidal Meningoencephalocele.

BACKGROUND: Preservation of the anterior cerebral arteries (ACAs) is important in the surgical management of frontoethmoidal meningoencephalocele (FEME). This would avoid complications related to the loss of blood supply to the part of the brain supplied by the ACA. Previous reports have identified hydrocephalus, microcephaly, cerebral dysplasias amounting to a 15% to 20% prevalence of brain anomalies in patients with FEME. What has not been previously reported are cerebral vasculature changes in the frontal region in FEME and how these may impact on the surgical correction and clinical outcome. METHODS: Two patients of FEME that demonstrate cautionary radiologic findings in relation to the ACAs and anterior fossa anatomy are discussed. RESULTS: The ACA in a 4-year-old boy with FEME was displaced anteriorly with the long A1 segments that extend into the defect. In the 2nd patient, a 4-year-old girl, we report on the complications related to the injury of ACAs from a previously partially resected FEME. CONCLUSION: The importance of the anterior cerebral vasculature around the FEME during surgery is crucial to prevent complications resulting from damage to a looping A1 segment of the ACA.

Factors impacting cerebrospinal fluid leak rates in endoscopic sellar surgery.

BACKGROUND: In patients undergoing transnasal endoscopic sellar surgery, an analysis of risk factors and predictors of intraoperative and postoperative cerebrospinal fluid leak (CSF) would provide important prognostic information. METHODS: A retrospective review of patients undergoing endoscopic sellar surgery for pituitary adenomas or craniopharyngiomas between 2002 and 2014 at 7 international centers was performed. Demographic, comorbidity, and tumor characteristics were evaluated to determine the associations between intraoperative and postoperative CSF leaks. Correlations between reconstructive and CSF diversion techniques were associated with postoperative CSF leak rates. Odds ratios (OR) were identified using a multivariate logistic regression model. RESULTS: Data were collected on 1108 pituitary adenomas and 53 craniopharyngiomas. Overall, 30.1% of patients had an intraoperative leak and 5.9% had a postoperative leak. Preoperative factors associated with increased intraoperative leaks were mild liver disease, craniopharyngioma, and extension into the anterior cranial fossa. In patients with intraoperative CSF leaks, postoperative leaks occurred in 10.3%, with a higher postoperative leak rate in craniopharyngiomas (20.8% vs 5.1% in pituitary adenomas). Once an intraoperative leak occurred, craniopharyngioma (OR = 4.255, p = 0.010) and higher body mass index (BMI) predicted postoperative leak (OR = 1.055, p = 0.010). In patients with an intraoperative leak, the use of septal flaps reduced the occurrence of postoperative leak (OR = 0.431, p = 0.027). Rigid reconstruction and CSF diversion techniques did not impact postoperative leak rates. CONCLUSION: Intraoperative CSF leaks can occur during endoscopic sellar surgery, especially in larger tumors or craniopharyngiomas. Once an intraoperative leak occurs, risk factors for postoperative leaks include craniopharyngiomas and higher BMI. Use of septal flaps decreases this risk.

Endoscopic surgery of skull base chordomas.

Objective To assess our clinical experience in treating midline intracranial pathology using minimally invasive surgical techniques. Design Retrospective chart review of patients undergoing endoscopic endonasal resection of clival chordomas. Setting Two tertiary referral centers in Australia and New Zealand. Main Outcome Measures Patients were assessed by intraoperative findings (macroscopic resection rate, tumor size, and operative complications) and clinical outcomes (residual disease, postoperative complications, recurrence rate, and mortality). Results Fourteen patients underwent endoscopic resection of clival chordomas (seven primary, seven revision) with a mean follow-up of 41.45 months (3 to 104 months). Macroscopic resection rates were 71% and 29%, respectively. Mean operative time was 386 minutes. Overall cerebrospinal fluid (CSF) leak rate was 3/14 (21%) and, using the nasoseptal flap, it was 0/5 (0%). Two patients developed late recurrence; one died of disease and one was treated with intensity modulated radiation therapy. Overall mortality was 2/14 (14%). Conclusion Endoscopic resection of clival chordomas is a safe and viable alternative to the traditional open approach. The nasoseptal flap is an excellent method of obtaining a watertight skull base closure. Furthermore, this series highlighted the fact that the primary attempt at surgery offers the best chance to achieve a total resection.