Abstract TP365: Surgical Performance in Minimally Invasive Surgery Plus rt-PA for ICH Evacuation (MISTIE) Phase III Clinical Trial

Abstract

Introduction: The MISTIE III trial aims to compare outcome following minimally invasive surgery plus thrombolysis versus best medical treatment for intracerebral hemorrhage (ICH). An image guided catheter is placed into the hematoma for ICH aspiration and rt-Pa administration. Surgeons at three levels of pre-specified experience with the procedure (pre-qualified PQ, qualified-probation QP, and fully qualified FQ) utilized one of three protocol-prescribed surgical approaches (anterior A, posterior B, and lobar C) based on the location and depth of the hematoma. Objective: To assess accuracy of catheter placement and efficiency of ICH evacuation in relation to surgical approach and surgeon experience in the first 89 cases randomized to surgical treatment in the ongoing trial (roughly third of projected enrollments), with 86 cases undergoing the procedure. Methods: The trial’s Surgical Center assessed prospectively the accuracy of initial catheter placement based on pre-articulated criteria, catheter replacement, and efficiency at ICH evacuation. Results: Average ICH volume was 49.7ml at clot stability, with mean 72 % evacuated post catheter removal. Approaches A, B and C were used in 52, 25, and 23% of cases, with overall good, suboptimal and poor catheter placements in 58, 31 and 10 % of cases, respectively. Catheters were replaced/repositioned in 24 cases. Approach B was associated with significantly higher rates of poor placement (27%) and replacements (68%) than the other approaches (P< 0.01). Surgeon experience was PQ, QP and FQ in 56, 20, and 24% of cases, and was not associated with significantly different placement accuracy or replacement rates. Relative reduction in volume of the hematoma by the end of treatment was not significantly different among the three approaches, nor among surgeons at the three levels of experience. Conclusion: Ongoing surgical education and quality monitoring in the MISTIE III trial have resulted in consistent rates of hematoma evacuation among surgeons of varying experience, and with different catheter trajectories, despite technical challenges with the posterior surgical approach. This documented optimization of the surgical task enhances the validity and subsequent generalizability of the ongoing trial.