The MIND study—presented for the first time at this year’s International Stroke Conference (ISC; 5–7 February, Los Angeles, USA)—has revealed the potential benefits of minimally invasive surgery in patients with deep and lobar intracranial haemorrhages (ICHs). Analyses of the study demonstrated a “substantial” reduction in haemorrhage volumes that was not accompanied by excess periprocedural mortality or adverse event rates in either ICH location, as well as “pronounced” early clinical improvements as per more favourable functional outcomes with surgery versus medical management at 30 days.
Delivering these late-breaking findings, David Fiorella (Stony Brook University Medical Center, Stony Brook, USA) initially informed the ISC 2025 audience that, despite the “considerable” health and economic burden of the condition, the majority of ICH patients are left without definitive treatment. Against this backdrop, Fiorella and his colleagues conducted the MIND study—a multicentre, prospective, open-label randomised controlled trial (RCT) comparing the safety and effectiveness of minimally invasive surgery with the Artemis neuro evacuation device (Penumbra) to best medical management in the treatment of spontaneous ICH.
This investigational device exemption (IDE) study enrolled patients with moderate-to-large-volume supratentorial ICH (20–80mL) presenting within 24 hours of symptom onset. Patients randomised to receive minimally invasive surgery underwent the procedure within 72 hours, while clinical follow-up took place at 24 hours post-intervention in the surgical arm versus 72 hours post-randomisation in the medical management arm, as well as at seven, 30, 90, 180 and 365 days, or at discharge. The study’s primary endpoints for effectiveness and safety were 180-day ordinal modified Rankin scale (mRS) scores and 30-day mortality, respectively. Key secondary endpoints included 365-day ordinal mRS scores, quality-of-life outcomes (EQ-5D-5L), procedure times and lengths of hospital stay.
Fiorella relayed that, in late 2022, a prespecified interim analysis of MIND following enrolment of the first 200 patients found no safety or futility-related concerns and therefore recommended continuation of the study. However, in early 2023, presentation of the ENRICH trial’s results—which demonstrated improved clinical outcomes versus standard care with minimally invasive surgery using the BrainPath and Myriad technologies (both Nico Corporation/Stryker) in lobar ICH—called into question the potential clinical equipoise of MIND, leading to enrolment of patients with primarily lobar ICHs being halted. Then, in mid-2023, an independent analysis of MIND accounting solely for randomised patients with deep ICHs projected a low probability of there being a statistically significant difference between the two study arms, resulting in enrolment being stopped altogether—across both ICH locations—in October of that year.
Ultimately, this left the MIND investigators with a final study population of 236 patients—one that was deemed to be underpowered to detect the study’s pre-established treatment effect size. Within this intention-to-treat population, 154 patients were allocated to minimally invasive surgery while 82 underwent medical management only. Fiorella reported comparable average times to randomisation and baseline ICH volumes between these two groups, also highlighting an average time to procedure of 27.5 hours in the study’s surgical arm. In addition, across these 236 patients, 29.2% had lobar ICHs while 70.8% had deep ICHs—with deep ICH patients generally being younger, and having more severe symptoms and a greater number of medical comorbidities versus their counterparts with lobar ICHs.
Describing procedural outcomes observed in those patients who received minimally invasive surgery in the MIND study, Fiorella relayed an 80.7% median rate of haematoma reduction—a “high” evacuation rate that proved to be comparable between deep and lobar ICH locations. The study also found that 79.2% of patients achieved the surgical goal of a haematoma volume of ≤15mL, and there were low rates of conversion to craniotomy (1.4%) and external ventricular drain (EVD) placement (12.5%) too. Fiorella went on to note a median procedure duration of 33.5 minutes, with surgeries to treat deep ICHs generally taking slightly longer than those involving lobar ICHs (37.5 vs 25.5 minutes, respectively). Additionally, minimally invasive surgery compared to medical management was found to have increased the odds of a favourable clinical outcome as per 30-day ordinal mRS scores—although, despite positive trends continuing, these indications did not reach statistical significance at 90 and 180 days, and mean 180-day utility-weighted mRS scores were similar between surgery and medical management within a per-protocol population (222 patients).
In the study’s as-treated population (234 patients), primary safety endpoint analyses showed a low overall mortality rate within 30 days across the two treatment arms (8.1%), with a rate of 7.2% in the surgical group and 9.8% in the medical management group. Here, Fiorella noted that mortality rates in the study’s medical management arm were roughly half of those reported in the literature among similar patient populations—leading the MIND investigators to speculate that, while minimally invasive surgery did not demonstrate any relative improvement in 30-day mortality rates, medical management may have ‘overperformed’ in the study and thus masked potential between-group discrepancies. He also commented that, when looking specifically at lobar ICHs, the 30-day mortality rate in MIND’s medical management arm (22.7%) was “more in line” with previously reported figures.
Later in his presentation, Fiorella moved on to discuss a number of noteworthy secondary endpoint findings, with the first being comparable Kaplan Meier-estimated survival probabilities between the study’s two treatment arms. Further analyses indicated that there were fewer serious adverse events reported at 180 days in the surgical arm—across both deep and lobar ICH—as compared to the medical management arm (52.6% vs 68.3%, respectively), while a lower incidence of a symptomatic evolution of perihaematomal oedema with surgery (2.6%) versus medical management (13.4%) suggested a 30-day reduction in secondary injury that did not carry increased bleeding risks. Per-protocol analyses also revealed median length-of-stay data that trended positively—if only very marginally—in favour of minimally invasive surgery, as well as substantially reduced 30-day intubation rates with surgery (3.6%) versus medical management (12.1%).
Finally, Fiorella alluded to a 0.7% rate of surgical complications with the Artemis system at 30 days, before concluding that “future studies are needed to optimise outcomes for ICH patients” and build on the many positive signals within the MIND trial.
