Potential Predictors for Length of Hospitalization in Patients Who Had Adjuvant Middle Meningeal Artery Embolization After Conventional Surgery for Chronic Subdural Hematomas

Introduction: Middle meningeal artery embolization (MMAE) is emerging as safe and effective treatment for carefully selected patients with chronic subdural hematomas (cSDH). MMAE has been used as a stand-alone therapy or as an adjunct treatment after open surgery to reduce recurrence of cSDH. The average length of hospitalization for conventional surgery or MMAE alone for cSDH is around 6-8 days. The predicting factors for length of hospitalization for these two treatment modalities have been studied. However, there is no data evaluating the effects of utilization of MMAE following conventional surgery on length of hospitalization.

Methods: A retrospective review of 39 cases with MMAE as an adjunct therapy after conventional surgery, between 2019 and 2022, was performed. Clinical and radiographic factors predictive of prolonged length of hospitalization were identified through univariate and multivariate analyses.

Results: Average length of hospitalization for MMAE after conventional surgery was 15.3 days (SD = 14.4), and the interval between the two procedures was 2.9 days (SD= 2.2). Among 39 patients, 19 stayed for less than 8 days, while 20 stayed for more than 8 days. Univariate analysis showed the interval between two procedures, pre-operative INR value, heart disease, overall complicated hospital course, medical complications, and procedure related complications were the predictors for prolonged hospitalization. However, multivariable analysis showed that the only independent predictor for prolonged stay is the time interval between conventional surgery and MMAE (odds ratio 2.6, 95% CI 1.1-6.2, p=0.03).

Conclusion : Among many factors, the interval between conventional surgery and MMAE was the strongest predictor for prolonged length of hospitalization in patients who had adjunct MMAE after conventional open surgery. This may inspire us to shorten the delay for MMAE after conventional surgery to decrease length of stay and unnecessary costs.