Abstract A148: Determination and validation of the optimal timing of minimally invasive surgery for ICH patients: a prospective, long-term follow-up, large sample, multi-center registry study

Introduction: In this study, we aimed to determine the efficacy and optimal timing of early frameless robot-assisted stereotactic aspiration coupled with catheter thrombolysis (SA-CT) in ICH patients. Method: This study included ICH patients who received conservative treatment or SA-CT from two prospectively registered multicenter cohort studies. Restricted cubic spline (RCS) function were used to determine the optimal surgical timing for SA-CT that could improve the prognosis of patients. Based on the optimal cutoff value, the study population was further classified into the early SA-CT group, the later SA-CT group and conservative group. The primary outcome included 3-month, 6-month and 12month modified Rankin scale of 3-6. The confounding factors of the three groups of patients were controlled through propensity score matching. Hypothetical randomization was emulated using inverse probability weighting, treated weighting, overlap weighting, matching weighting and entropy weighting. A logical model was adopted to estimate the association between the treatment protocols and neurological function prognosis. Results: A total of 2211 ICH patients were included, 1075 received conservative treatment and 1136 underwent SA-CT. The RCS function indicated that undergoing SA-CT within 1.9 to 10.3 hours after the onset can improve the 1-year neurological prognosis (early SA-CT group, n=519). The results after propensity score matching showed that compared with the conservative treatment group, the risk of poor prognosis at 12 months after the onset in the early SA-CT group decreased by 69.5% (OR=0.305, 95% CI=0.181 to 0.509, P < 0.001), and the risk of poor prognosis at 6 months dropped to 48.9% (OR=0.511, 95% CI=0.317 to 0.818, P =0.005). Furthermore, the risk of poor prognosis at 12 months in the early group was reduced to 41.6% (OR=0.416, 95% CI=0.251 to 0.678, P = 0.001) compared to that in the late group. The result remained consistent after weighting by the 3 methods. The mortality of the early surgery group at 3 months, 6 months and 12 months after the onset were all lower than those of the other two groups (all P < 0.001). Conclusion: Early SA-CT is safe and effective, and its optimal timing maybe between 2-10 hours after onset. In addition, we found that the advantages of surgical intervention need to be followed up for 6-12 months to show.