En-bloc resection achieves higher GTR rates with similar neurological outcomes in grade-2 intramedullary spinal ependymomas: single-centre cohort study

Gross total resection (GTR) improves progression-free and overall survival in CNS WHO grade 2 intramedullary spinal ependymomas. En bloc resection (circumferential dissection and removal in one piece) may maximise GTR while preserving cord integrity, compared with piecemeal resection (internal debulking and fragmentary removal). To compare en bloc and piecemeal resection strategies with respect to GTR rates, neurological outcomes and disease relapse. A retrospective cohort study of 39 patients treated over a 13-year period at a single tertiary centre. Primary outcomes were extent of resection and neurological deterioration (modified McCormick Scale). Disease relapse (post-GTR recurrence or post-STR progression) was a secondary outcome. On multivariate analysis, en bloc resection independently predicted GTR (OR 6.54, 95% CI 1.14–37.5, p = 0.035), while the presence of a syrinx was associated with reduced odds of GTR (OR 0.08, p = 0.047). Neurological deterioration (≥1 mMCS grade) did not differ significantly between techniques (36.4% vs 58.8%, p=NS). Disease relapse occurred in five patients and was strongly associated with residual tumour (OR 44.4, p = 0.003). Residual disease was the dominant predictor of relapse. En bloc resection was associated with higher GTR rates without evidence of increased neurological morbidity, identifying surgical strategy as a potentially modifiable determinant of oncological outcome. These findings are hypothesis-generating and support prospective, multicentre studies to define evidence-based resection strategies. For CNS WHO Grade 2 intramedullary spinal ependymoma: Residual disease following surgery is strongly predictive of disease relapse. Achieving GTR at index or staged reoperation is prognostically critical. En bloc resection strategy is associated with increased GTR rates, without evidence of elevated neurological risk. Syrinx is associated with reduced GTR rates. Multi-centre prospective controlled trials are required to define evidence-based resection strategies.