Abstract
AIMS
Retraction is a critical step in surgical removal of brain tumours, enabling visualisation and resection. Conventional retraction applies focal pressure to overlying tissue, potentially resulting in retraction-induced injury. Tubular retractors (minimally invasive parafascicular surgery) circumferentially distribute pressure to theoretically minimise injury. Whilst previous reviews have provided insight into their potential, the literature has since significantly expanded, necessitating an update. The objective was to synthesise all current evidence regarding surgical outcomes of tubular retractors in resection of brain tumours.
METHOD
Studies reporting on use of tubular retractors to resect brain tumours in adult patients were eligible. PRISMA guidelines were followed. MEDLINE, Embase and the Cochrane Library were searched to 18th October 2023. Duplicate title/abstract screening, data extraction and risk of bias assessments were conducted.
RESULTS
Of the 2453 studies screened, 49 were included in the final synthesis, involving 690 patients. Tubular retractor systems assessed were: BrainPath (n=199), VBAS (n=198), METRx (n=63) and other (n=230). Pooled estimate of gross total resection rate was 75% (95% CI 0.65-0.84; I2=83%), whilst pooled estimate of complication rate was 17% (95% CI 0.11-0.24; I2=75%). Sub-group analysis of gross total resection rate was conducted for: glioma (150 patients, pooled prevalence 47%, 95% CI 0.36-0.57; I2=29%), colloid cyst (121 patients, pooled prevalence 100%, CI 0.99-1.00; I2=0%), and metastasis (114 patients, pooled prevalence 82%, 95% CI 0.67-0.94; I2=64%). There was no significant difference between tubular retractor systems with regards to gross total resection or complication rate (p>0.05).
CONCLUSION
There is mounting evidence for the utility of tubular retractors in resection of brain tumours. However, this evidence remains largely in the form of low-quality case-series, providing proof-of-concept, but limited in its ability to draw more robust comparisons to conventional retraction. Future studies with greater sample sizes and inclusion of control groups are now needed to consolidate the position of tubular retractors in neuro-oncology.