Main outcome measures, variables, and data sources
Anonymised data was collected from patients’ electronic clinic letters
and operation notes for age, histological diagnosis, site of the tumour,
date of operation, details of surgical management, postoperative
complications, need for revision surgery and outcome at five years
post-operatively (or most recent follow up if less than five years).
Surgical procedures were classified as primary if surgery was conducted
at our centre for the first time and secondary if a prior attempted
resection had been undertaken elsewhere.
Statistical analysis was done using a Chi-squared calculation with the
significance level of p<0.05.