Related Experiment Video
Updated: Jun 20, 2026
The Transition to an Anterior-Based Muscle Sparing Approach Improves Early Postoperative Function but is Associated with a Learning Curve
Published on: September 7, 2022
'To improve is to change'-but is it safe? A single surgeon's transition from lateral to vertical hemispherotomy
Omar Salim1, Aswin Chari2,3, M Zubair Tahir4,5
1Department of Clinical Neurosciences, Royal Infirmary of Edinburgh, Edinburgh, UK.
Purpose:
Hemispherotomy is an established treatment for children with drug-resistant epilepsy. Recent reports have suggested a superiority of outcomes with the vertical approach compared to the traditional lateral approach. This study investigated whether an experienced epilepsy surgeon can safely transition from lateral peri-Sylvian to vertical parasagittal hemispherotomy, through evaluation of postoperative seizure freedom and associated outcomes.
Methods:
Thirty-six patients who underwent hemispherotomy by a single surgeon between 2016 and 2025 were analysed, 23 lateral peri-Sylvian and 13 vertical parasagittal. Pre-, peri- and postoperative findings were compared across the two techniques, with Pearson's chi-squared, Fisher's exact and Mann-Whitney U tests utilised where appropriate to detect significant differences. Patients with 1-year postoperative follow-up were split into chronological epochs. A binary logistic regression model compared seizure freedom by epoch whilst controlling for factors shown to predict seizure freedom.
Results:
90.9% of the lateral group and 83.3% of the vertical group were seizure free (Engel class I) at 1-year postoperative follow-up (p = 0.602), with no statistically significant differences in the complication rates. Mean operative duration was significantly less for the vertical compared to the lateral group (340.9 vs 448.8 min, p = 0.002), as was intraoperative haemoglobin drop (18.1 vs 27.2 g/L, p = 0.002). Mean hospital stay was comparable (8.7 vs 9.8 days, p = 0.871). There was no statistically significant difference in 1-year seizure freedom rate noted by chronological epoch whilst adjusting for factors predicting seizure freedom (p = 0.816).
Conclusion:
This study demonstrates that a single experienced epilepsy surgeon can safely transition between techniques, without compromising on seizure freedom outcomes or incurring additional morbidity. Whilst larger studies may demonstrate the favourability of one technique over the other, it may be useful to the individual surgeon to have a sound grasp of both techniques in their armamentarium.
