In Reply: Safety of Postembolization Antithrombotic Therapy After Middle Meningeal Artery Embolization

To the Editor: We appreciate the insightful commentary by Xiaolin Du et al1 on our recent manuscript “Safety of Postembolization Antithrombotic Therapy After Middle Meningeal Artery Embolization”2 and welcome the opportunity to contribute to the continued discussion. We agree with the authors' assessment that proper patient identification is important in minimizing treatment failure after middle meningeal artery embolization (MMAE). Our past research has explored the association of preoperative surgical risk factors with outcomes and supported Charlson Comorbidity Index as an independent predictor of chronic subdural hematoma (cSDH) resolution (odds ratio: 0.66 per point; 95% CI: 0.48, 0.91; P-value = .0061).3 The recurrence rate we observed in this study is in line with much of the literature, with cSDH recurrence rates reported between 3% and 11% in various studies of MMAE outcomes.4 The variance in recurrence rates may also be attributable to differences in how recurrence is defined, with some studies defining only symptomatic reaccumulation as recurrence while others defined both symptomatic and asymptomatic reaccumulation as recurrence.5 We used a liberal definition of recurrence including asymptomatic reaccumulation in our study, which may be responsible for the comparatively higher prevalence in our sample. As cited in our limitations, progressive hematoma resolution after cSDH continues to occur at least 6 months postoperatively, making our shorter median follow-up time suggest an underprediction of cSDH resolution in certain cases.6 As such, we do not believe we can accurately claim length of follow-up as a mediator for resolution without additional data and multivariable analysis. The similarity in major outcomes noted at the authors' institution between concomitant surgical evacuation cases and standalone MMAE is similar to our institutional outcomes and further supported by recent meta-analysis of the MMAE literature.7 We agree that our manuscript on early antithrombotic reintroduction after MMAE should join earlier literature by Mir et al and Martinez-Gutierrez et al to encourage larger, multi-institutional analysis or randomized controlled trials on the outcomes of early antithrombotic reinitiation after MMAE.8,9 We agree that atorvastatin is an important therapy in the management of cSDH, and we use it routinely in our practice based on a recent clinical trial.10 We believe that there are many potential opportunities of novel treatments of cSDH and are excited to see what the future will bring.