ENRICH Trial Findings Debuts at the 2023 American Association of Neurological Surgeons Annual Scientific Meeting

Newswise — The latest science and trial results were unveiled during the 2023 American Association of Neurological Surgeons (AANS) Annual Scientific Meeting in Los Angeles. The late-breaking abstract “Efficacy and Safety of Early Minimally Invasive Removal of Intracerebral Hemorrhage (ENRICH): a Multicenter Randomized Adaptive Trial,” was showcased Saturday, April 22.

The abstract was authored by Gustavo Pradilla, Jonathan J. Ratcliff, Alex J. Hall, Benjamin R. Saville, Jason W. Allen, Michael Frankel, David W. Wright, Daniel L. Barrow, and for the ENRICH Investigators.

Supratentorial intracerebral hemorrhage (ICH) accounts for 10-15% of all strokes and results in significant morbidity and mortality. The ENRICH Trial evaluated a Minimally Invasive trans-sulcal, Parafascicular Surgery (MIPS) approach. Between December 1, 2016, and August 24, 2022, eligible patients were randomized to either MM or MIPS at 37 centers in the United States. At the second interim analysis (175 enrolled), a pre-specified stopping criterion was met for the ABG location resulting in a study adaptation. Per design, the ABG location was halted and all subsequent participants were enrolled (enriched) meeting lobar location criteria. The trial randomized 300 participants, with 92 (30.7%) in the ABG location and 198 (69.3%) in the lobar location. There were no observed baseline differences between groups for age, ICH volume, GCS or NIHSS.

Overall mortality at 6 months was 21.3% (22.7% in the MM group and 20.7% in the MIPS group). In the MIPS group, median extent of hematoma evacuation was 87.7% with a median end-of-treatment volume (EOTV) of 7.2mL. Goal EOTV <15mL was reached in 72.7%. An mRS at 6 months was obtained in 286 participants (95.3%): 139 in the MM group (40 ABG and 99 lobar) and 147 in the MIPS group (47 ABG and 100 Lobar).

The Bayesian primary analysis compared the mean UWmRS at 6 months between treatment groups, with an estimated mean UWmRS of 0.376 for the control and 0.456 for the MIPS group, with a difference of 0.0793. The Bayesian posterior probability of superiority of the intervention was 0.9762, which exceeded the pre-specified 0.975 threshold to claim superiority of MIPS versus MM. The observed difference in mean UWmRS was -0.0488 in the ABG location, 0.1386 in the lobar location. Differences greater than 0 correspond to improved outcomes in the treatment group.

This is the first clinical trial to demonstrate the functional benefit of surgical clot evacuation among participants with supratentorial ICH presenting within 24 hours of LKN. MIPS was deemed safe, resulted in substantial clot evacuation and improved the UWmRS at 6 months relative to standard management. The overall benefit of MIPS appears to be from the strong positive effect observed for participants with lobar ICH.

About the 2023 AANS Annual Scientific Meeting:

From April 21-24, 2023, in in Los Angeles, California, neurosurgeons, neurosurgical residents, medical students, neuroscience nurses, clinical specialists, physician assistants, allied health professionals and other medical professionals will join together for the 2023 AANS Annual Scientific Meeting. The annual meeting is the largest gathering of neurosurgeons in the nation, with an emphasis on the field’s latest research and technological advances. The scientific presentations scheduled for the 2023 event represent cutting-edge examples of the incredible developments taking place within the field of neurosurgery.

About the AANS:

Founded in 1931 as the Harvey Cushing Society, the American Association of Neurological Surgeons (AANS) is a scientific and educational association with more than 13,000 members worldwide. The AANS promotes the highest quality of patient care and advances the specialty of neurological surgery. Fellows of the AANS are board-certified by the American Board of Neurological Surgery, the Royal College of Physicians and Surgeons of Canada or the Mexican Council of Neurological Surgery, A.C. Neurosurgery is the medical specialty concerned with the prevention, diagnosis, treatment and rehabilitation of disorders that affect the spinal column, spinal cord, brain, nervous system and peripheral nerves.

 For more information, visit www.AANS.org.