Introduction: Neurosurgical resection of epidermoid tumors can be quite challenging and potentially morbid, leading to questions surrounding extent of resection. In the largest meta-analysis to date of patients with epidermoid tumors, we compared recurrence rates for STR (sub-total resection) and GTR (gross total resection) and the associated complications.
Methods: A systemic literature review following the PRISMA guidelines was completed followed by a proportional meta-analysis to compare the pooled recurrence rates between STR and GTR in epidermoid tumors. Fixed- and mixed-effect models were used to compare the pooled proportions of recurrence after STR or GTR. The relationship between recurrence rate and follow-up time was studied using linear regression and natural cubic spline models.
Results: Twenty-seven studies with 691 patients met our inclusion criteria, among whom, 293 (42%) underwent STR, while 398 (58%) received GTR. The average recurrence rate of all procedures was 11%. The proportional meta-analysis showed that the pooled recurrence rate after STR (21%) was 7 times that after GTR (3%). The most common surgical complications were transient cranial nerve palsies, occurring equally in STR and GTR cases when reported. The average recurrence rate for studies with longer follow-up time (> 4.4 years) (17.4%) was significantly higher than the average recurrence rate for studies with shorter follow-up time (< 4.4 years) (5.7%).
Conclusions: STR of epidermoid tumors is associated with a significantly higher rate of recurrence (~ 7 times) compared to GTR and correlates with time such that more recurrences, on average, are observed after longer post-operative periods of time. Types of complications, and their frequencies, do not seem to differ between STR and GTR. Attempts at GTR, when appropriate, should be made during the initial surgery with efforts to optimize success. In all post-operative epidermoid tumor cases, but particularly following STR, close follow-up with serial MRIs, even years after surgery, is recommended.
Patient Care: Our group presents the results of the largest meta-analysis to date analyzing the extent of neurosurgical resection and rate of recurrence of epidermoid tumors. Our findings are timely as they help address the ongoing debate with regards to surgical management of this tumor type and extent of resection and provide valuable insight into the need for close follow-up of these tumors, even years after surgery and after gross total resection. These results also address potential complications associated with initial surgery, as well as reoperations, and emphasize factors that may help enhance patient outcomes.
Learning Objectives: 1. To better understand the pathophysiology, underlying genomics and natural history of intracranial epidermoid tumors.
2. To appreciate the difference in outcomes, specifically related to tumor recurrence, between tumors that are subtotally or gross totally resected and the complications associated with each surgical approach.
3. To identify and discuss surgical considerations to optimize safety and extent of resection of epidermoid tumors.