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DOI: 10.1055/s-0037-1600678
Is The Chiasm - pituitary Corridor Important for Achieving Gross Total Resection in Craniopharyngiomas?
Publication History
Publication Date:
02 March 2017 (online)
Introduction: Craniopharyngiomas arise from the pituitary stalk and generally are located posterior to the chiasm extending behind the chiasm into the third ventricle. The extended endonasal approach (EEA) can provide an ideal corridor between the bottom of the optic chiasm and the top of the pituitary gland (Chiasm-Pituitary Corridor (CPC) for their removal. A narrow CPC with a large tumor extending up and behind the chiasm has been considered a contraindication to EEA with a high risk of visual deterioration and subtotal resection.
Method: A database of all patients treated in our center between July 2004 and August 2016 was reviewed. Patients with craniopharyngiomas who underwent EEA with the goal of GTR were included in the study. Patients with postfixed chiasm or limited available preoperative imaging were excluded. Using preoperative contrast enhanced T1W sagittal midline MRI, we calculated the CPC as well as the distance from the chiasm to the top of the tumor (CTOT). From these numbers we calculated a ratio of the CPC to the CTOT as measure of difficulty in removing the tumors through the EEA and called this ratio the corridor index (CI). The relationship between the CI and the ability to achieve GTR and visual outcome were measured.
Results: Thirty-four patients were included in the study. The mean CPC was 9.9 mm (range 5.05–18.1 mm). The mean CTOT was 12.69 mm (range 0–28.1 mm). The median CI was 0.69, which ranged from 0.33 to infinity (for tumors with CTOT =0). Thirty-two patients had GTR and two had STR (CIs=1.12 and 0.63). The CPC value had no relationship with our ability to achieve GTR and no effect on visual outcome.
Conclusion: EEA for craniopharyngioma is generally considered the first line surgical approach. Although a narrow corridor between the top of the pituitary gland and the bottom of the chiasm may seem to be a relative contraindication to surgery for larger tumors, our data does not bear this out. EEA appears to be a successful technique for the majority of midline craniopharyngiomas.