Comparisons of the seizure-free outcome and visual field deficits between anterior temporal lobectomy and selective amygdalohippocampectomy: a systematic review and meta-analysis

Abstract Purpose The purpose of our study is to compare seizure-free outcome and the incidence of visual field deficits (VFD) between anterior temporal lobectomy (ATL) and selective amygdalohippocampectomy (SAH) among patients with intractable temporal lobe epilepsy (TLE). Methods We searched MEDLINE, Embase and Cochrane databases using keywords related to ATL, SAH and VFD. Previous studies that compared ATL and SAH with seizure-free outcome and the incidence of VFD were included. A fixed-effect model was used to conduct meta-analysis. Risk ratio with 95% confidence intervals were pooled and used to elucidate each outcome. Results Twenty-three retrospective and three prospective studies were recruited with a total of 2930 cases (1390 cases for SAH and 1540 cases for ATL). The meta-analysis showed no significant difference in seizure freedom (SAH 63.5% vs ATL 63.8%) of these two procedures (RR 0.95, 95%CI 0.90-1.01, P = 0.102), but the odds of seizure freedom in ATL was higher than transsylvian SAH approach (RR 0.89 95% CI 0.82-0.96, P =  0.004). Comparing with ATL for TLE, SAH for TLE caused lower frequency of postoperative VFD. (RR 0.87, 95%CI 0.76-0.99, P = 0.034). Conclusions There was no significant difference on seizure freedom between ATL and SAH procedures, while subgroup analysis demonstrated that ATL was associated with higher opportunity to achieve seizure-free than transsylvian SAH approach. Furthermore, the incidence of postoperative VFD was significantly lower in SAH than ATL. Individualized treatment achieving balance between seizure free and collateral damage should be considered in clinical practice. Well-designed randomized controlled clinical trials would be necessary to validate our findings.