Objective: Hypothalamic hamartoma (HH) is a rare, nonmalignant, heterotopic developmental malformation that consists of a mixture of normal neurons and glial cells. Resection of HHs has been associated with high rates of mortality and morbidity. Therefore, minimally invasive ablation methods could be the best treatment option for HH. The most frequently used minimally invasive options for HH ablation are radiofrequency thermocoagulation (RFT), laser ablation (LA), and stereotactic radiosurgery.
Methods: To investigate three minimally invasive procedures in the treatment of refractory seizures related to HH, the authors conducted a systematic search in March 2022 in the MEDLINE, Embase, Scopus, and Web of Science databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Seizure freedom was the primary outcome of interest. The authors defined seizure freedom as Engel class I or International League Against Epilepsy class 1 or 2 or as the reported term "seizure freedom." The secondary outcome was long-term complications reported in studies. Both random- and fixed-effects models were used to calculate the pooled proportion of seizure freedom and complication rate with 95% confidence intervals. A modified version of the Joanna Briggs Institute (JBI) Critical Appraisal to assess the risk of bias was used.
Results: The authors included 15 studies with 422 patients (RFT, n = 190; LA, n = 171; and Gamma Knife Radiosurgery [GKRS], n = 61). Generally, the mean incidences of overall seizure freedom after minimally invasive procedures were 77% (95% CI 0.74-0.81) and 68% (95% CI 0.57-0.79) using fixed- and random-effects models, respectively. The mean incidence of overall seizure freedom after RFT was 69% (95% CI 0.63-0.75), and the mean incidences of overall seizure freedom after LA and GKRS were 87% (95% CI 0.82-0.92) and 44% (95% CI 0.32-0.57), respectively. The total complication rate with minimally invasive procedures was 13% (95% CI 0.01-0.26). The complication rate in each treatment was as follows: 5% (95% CI 0.0-0.12) for RFT, 20% (95% CI 0.0-0.47) for LA, and 22% (95% CI 0-0.65) for GKRS. Meta-regression analysis showed an association between older age and higher complication rates in the LA group.
Conclusions: In this meta-analysis, LA showed superiority in seizure freedom over the other two methods. The complication rate associated with RFT was less than those in the other two methods; however, this difference was not statistically significant.
Keywords: hypothalamic hamartoma; laser ablation; radiofrequency thermocoagulation; seizure; stereotactic radiosurgery.