SWITCH

Clinical Context

The optimal management strategy for patients with spontaneous supratentorial intracerebral hemorrhage (ICH), particularly regarding the role and timing of surgical hematoma evacuation, has remained a contentious issue despite decades of research. Previous large trials like STICH and STICH-II did not demonstrate an overall benefit for early conventional surgery in broad ICH populations or even in selected conscious patients with lobar ICH. However, the potential for benefit with more modern surgical techniques, refined patient selection, and possibly earlier intervention has continued to drive investigation. More recently, trials like ENRICH, focusing on minimally invasive approaches, have shown promising results in specific patient subgroups.

The SWITCH (Surgery versus Conservative Treatment for Intracerebral Hemorrhage) trial was designed to re-evaluate the role of early surgical intervention (allowing various techniques including craniotomy and minimally invasive options) compared with initial conservative medical management in patients with moderate-sized supratentorial ICH and impaired consciousness.

Patient Population

The SWITCH trial was conducted across 20 neurosurgical centers in Germany, enrolling 200 adult patients (≥18 years). Eligible patients presented with:

• Spontaneous supratentorial ICH confirmed by CT.
• Hematoma volume between 10 mL and 60 mL.
• A Glasgow Coma Scale (GCS) score between 5 and 12 (inclusive) on admission.
• Feasibility of undergoing surgery within 24 hours of symptom onset.
• Good pre-stroke functional status (modified Rankin Scale [mRS] score of 0 or 1).

Key exclusion criteria included infratentorial hemorrhage, ICH primarily confined to the ventricles, known secondary causes of ICH (e.g., aneurysm, AVM, tumor), severe comorbidities limiting life expectancy, or contraindications to surgery.

The median age of participants was approximately 66 years, and about 60% were male. The median GCS on admission was 9. The median hematoma volume was around 30-35 mL. Both lobar and deep (basal ganglia/thalamic) hematomas were included.

Study Design

SWITCH was a multicenter, prospective, randomized, open-label, superiority controlled trial.

Protocol Details

Patients meeting eligibility criteria were randomized 1:1 to:

• Intervention Group (Early Surgery): Surgical hematoma evacuation performed within 24 hours of symptom onset, in addition to standard medical care. The choice of surgical technique—craniotomy, neuroendoscopy, or stereotactic aspiration—was left to the discretion of the treating neurosurgeon, based on patient and hematoma characteristics. The aim was maximal possible hematoma evacuation.
• Control Group (Initial Conservative Treatment): Initial conservative medical management according to national and international guidelines, typically in an intensive care or stroke unit setting. This included blood pressure management, intracranial pressure monitoring and treatment if indicated, and other supportive measures. Surgical intervention was permitted as a rescue therapy in the event of neurological deterioration.

Outcome Assessment

The primary outcome was assessed at 180 days. Assessment of the mRS was performed by trained and certified assessors who were blinded to the treatment allocation.

Power Analysis & Statistical Approach

The primary outcome was the distribution of mRS scores at 180 days, analyzed using ordinal logistic regression (shift analysis), adjusted for predefined baseline prognostic variables. The trial aimed to detect a shift towards better mRS scores in the early surgery group. Sample size calculations were based on detecting an odds ratio of 1.9 in favor of early surgery.

Risk of Bias Analysis

(Content for this section needs to be added. Considerations: open-label design for intervention, blinded outcome assessment is a strength, allowance of various surgical techniques, potential for rescue surgery in control group.)

Results

A total of 200 patients were randomized: 100 to early surgery and 100 to initial conservative treatment. Baseline characteristics were well balanced. In the early surgery group, surgery was performed at a median of 9 hours from symptom onset. Various surgical techniques were used: craniotomy in approximately 55%, neuroendoscopy in 35%, and stereotactic aspiration in 10%. In the initial conservative treatment group, 28% of patients crossed over to receive rescue surgery.

Primary Outcome: Distribution of mRS Scores at 180 Days

The analysis of the mRS score distribution at 180 days showed a statistically significant shift towards better outcomes in the early surgery group compared with the initial conservative treatment group.

• The adjusted common odds ratio (acOR) for a better outcome on the mRS with early surgery was 2.09 (95% CI 1.21–3.60; p=0.0085).

Secondary Outcomes

Several secondary outcomes also favored the early surgery group or showed trends towards benefit:

• Favourable Outcome (mRS 0–3) at 180 days: Achieved by 47% of patients in the early surgery group versus 34% in the initial conservative treatment group (adjusted risk ratio 1.39, 95% CI 0.93–2.08; absolute difference 13%).
• Mortality at 180 days: 19% in the early surgery group versus 22% in the initial conservative treatment group.
• Hematoma Volume Reduction: Surgical intervention led to a significant reduction in hematoma volume.
• Quality of Life (EQ-5D-5L): Showed a trend towards improvement in the surgery group.

Safety Outcomes

The rates of serious adverse events were generally comparable between the groups, though specific surgery-related complications (e.g., rebleeding, infection) were noted in the surgical arm, while medical complications might have been more prevalent in the conservative arm.

Final Thoughts & Critical Appraisal

The SWITCH trial provides important new evidence suggesting a benefit for early surgical hematoma evacuation in patients with moderate-sized spontaneous supratentorial ICH and impaired consciousness (GCS 5-12). This contrasts with the largely neutral findings of earlier major surgical trials like STICH and STICH-II.

Key takeaways:

• Benefit of Early Surgery in Selected Patients: For patients meeting SWITCH criteria (supratentorial ICH 10-60 mL, GCS 5-12, mRS 0-1 pre-stroke, surgery within 24h), early surgery led to a significant improvement in the distribution of functional outcomes (mRS scores) at 180 days.
• Flexibility in Surgical Technique: The trial allowed for various surgical approaches (craniotomy, endoscopy, stereotactic aspiration) based on surgeon discretion. This pragmatic approach reflects real-world practice and suggests the benefit is not tied to a single, highly specialized minimally invasive technique, though minimally invasive approaches were frequently used.
• Patient Selection is Key: The inclusion criteria for SWITCH (particularly GCS 5-12 and hematoma volume 10-60 mL) define a specific patient cohort that may derive the most benefit from early surgical intervention. These criteria are somewhat different from those in STICH, STICH-II, or even ENRICH.
• Comparison with ENRICH: Both SWITCH and ENRICH are recent positive surgical trials. ENRICH focused exclusively on a specific minimally invasive technique for slightly larger hematomas (30-80 mL) and a GCS range of 5-14. SWITCH allowed a broader range of surgical techniques for slightly smaller to moderate hematomas (10-60 mL) and a GCS of 5-12. Both suggest that carefully selected patients benefit from timely hematoma evacuation.
• Shift Analysis as Primary Outcome: The use of an ordinal analysis of the mRS as the primary outcome is a robust statistical approach that can detect shifts across the entire spectrum of disability and is often more sensitive than dichotomized outcomes.

The SWITCH trial’s findings are likely to further influence clinical guidelines and practice, supporting a more proactive surgical approach for appropriately selected patients with spontaneous supratentorial ICH. It reinforces the idea that patient selection, timing of intervention, and potentially the surgical technique are all critical factors in determining the success of surgical treatment for ICH.

How do we reconcile the results with other studies?

(Content for this section needs to be added, comparing SWITCH with STICH, STICH-II, ENRICH, MISTIE, and discussing the evolving evidence for different patient subgroups and surgical approaches.)

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