Hemicraniectomy after middle cerebral artery infarction with life-threatening Edema trial (HAMLET). Protocol for a randomised controlled trial of decompressive surgery in space-occupying hemispheric infarction

Appreciation of the informed consent procedure in a randomised trial of decompressive surgery for space occupying hemispheric infarction

BACKGROUND AND AIM

As non-randomised studies have suggested that surgical decompression may reduce mortality in patients with space occupying hemispheric infarction, randomisation may be considered unethical in controlled trials testing this treatment strategy. We studied differences in recall of information and in appreciation of the informed consent procedure between representatives included in the Hemicraniectomy After Middle cerebral artery infarction with Life-threatening Edema Trial (HAMLET) and representatives of patients participating in the randomised trial of Paracetamol (Acetaminophen) In Stroke (PAIS).

METHODS

1 year after study inclusion, we contacted 30 consecutive representatives who had given informed consent for participation of their relative in HAMLET, and 30 for PAIS. Recall of trial details and appreciation of the informed consent procedure were investigated using standardised questionnaires and compared between the two groups.

RESULTS

All 30 PAIS representatives and 28 HAMLET representatives were interviewed. Participation of their relative in a clinical trial was remembered by 86% of HAMLET and 40% of PAIS representatives (p<0.001). HAMLET representatives remembered more trial details (effect of the treatment under study (61% vs 3%, p<0.001); randomised treatment allocation (71% vs 0%, p<0.001)). With respect to appreciation of the informed consent procedure, we found no differences between the groups: in each trial, four representatives (14% vs 13%) had considered the question of randomisation unacceptable.

CONCLUSIONS

Participation of patients in a randomised controlled trial of surgical decompression for space occupying infarction is generally considered acceptable by their representatives, and recall of trial details is better than in a trial in which less vital issues are at stake.

Trading death and disability in malignant stroke

Investigating introspective aspects of informed consent in a contemporary stroke trial

Antiedema therapy in ischemic stroke

Life-threatening, space-occupying brain edema occurs in up to 10% of patients with supratentorial infarcts and is traditionally associated with a high mortality rate of up to 80%. Management of these patients is currently being changed to an earlier and more aggressive treatment regimen. Early surgical decompression has recently been proven effective to reduce mortality and increase the number of patients with a favorable outcome in randomized controlled trials and is now the "antiedema" therapy of first choice for patients with large middle cerebral artery infarction aged 60 years or younger. Several medical treatment strategies have been proposed to control brain edema and reduce intracranial pressure, including different osmotherapeutics, hyperventilation, tromethamine, hypothermia, and barbiturate coma. None of these treatments is supported by level 1 evidence of efficacy in clinical trials, and some of them may even be detrimental. Preliminary results on hypothermia for space-occupying hemispheric infarction are encouraging, but far from definitive.

New algorithm for treatment allocation reduced selection bias and loss of power in small trials

OBJECTIVE

In clinical trials, patients become available for treatment sequentially. Especially in trials with a small number of patients, loss of power may become an important issue, if treatments are not allocated equally or if prognostic factors differ between the treatment groups. We present a new algorithm for sequential allocation of two treatments in small clinical trials, which is concerned with the reduction of both selection bias and imbalance.

STUDY DESIGN AND SETTING

With the algorithm, an element of chance is added to the treatment as allocated by minimization. The amount of chance depends on the actual amount of imbalance of treatment allocations of the patients already enrolled. The sensitivity to imbalance may be tuned. We performed trial simulations with different numbers of patients and prognostic factors, in which we quantified loss of power and selection bias.

RESULTS

With our method, selection bias is smaller than with minimization, and loss of power is lower than with pure randomization or treatment allocation according to a biased coin principle.

CONCLUSION

Our method combines the conflicting aims of reduction of bias by predictability and reduction of loss of power, as a result of imbalance. The method may be of use in small trials.

Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral Artery (DESTINY): a randomized, controlled trial

BACKGROUND AND PURPOSE

Decompressive surgery (hemicraniectomy) for life-threatening massive cerebral infarction represents a controversial issue in neurocritical care medicine. We report here the 30-day mortality and 6- and 12-month functional outcomes from the DESTINY trial.

METHODS

DESTINY (ISRCTN01258591) is a prospective, multicenter, randomized, controlled, clinical trial based on a sequential design that used mortality after 30 days as the first end point. When this end point was reached, patient enrollment was interrupted as per protocol until recalculation of the projected sample size was performed on the basis of the 6-month outcome (primary end point=modified Rankin Scale score, dichotomized to 0 to 3 versus 4 to 6). All analyses were based on intention to treat.

RESULTS

A statistically significant reduction in mortality was reached after 32 patients had been included: 15 of 17 (88%) patients randomized to hemicraniectomy versus 7 of 15 (47%) patients randomized to conservative therapy survived after 30 days (P=0.02). After 6 and 12 months, 47% of patients in the surgical arm versus 27% of patients in the conservative treatment arm had a modified Rankin Scale score of 0 to 3 (P=0.23).

CONCLUSIONS

DESTINY showed that hemicraniectomy reduces mortality in large hemispheric stroke. With 32 patients included, the primary end point failed to demonstrate statistical superiority of hemicraniectomy, and the projected sample size was calculated to 188 patients. Despite this failure to meet the primary end point, the steering committee decided to terminate the trial in light of the results of the joint analysis of the 3 European hemicraniectomy trials.

The role of surgery in ischemic stroke: decompressive surgery

PURPOSE OF REVIEW

This review gives an integrated view on the current status of decompressive surgery in space-occupying hemispheric brain infarction with a focus on new developments based on the available data of recent clinical trials, also including preliminary data from randomized trials reported at international stroke conferences in 2006.

RECENT FINDINGS

The treatment of ischemic brain infarction with life-threatening space-occupying edema is, because of a lack of prospective studies, one of the major controversial issues within neurocritical care medicine today. Only a few years ago, massive cerebral infarctions were regarded an untreatable disease with fatal outcome. The introduction of decompressive surgery (hemicraniectomy) has completely changed this point of view. Most of the reports, however, are retrospective with low numbers of patients. There are only few prospective trials that suggest a substantial benefit of decompressive surgery to significantly reduce mortality as compared to maximal conservative treatment alone. The control groups in these studies, however, consist of patients with higher age and higher rates of co-morbidities. Also, in most studies information on long-term outcome is insufficient. In 2006 long expected preliminary data from randomized trials of hemicraniectomy have been reported at international stroke conferences. They yield very positive results.

SUMMARY

Decompressive surgery appears to be a promising treatment option for patients with space-occupying hemispheric brain infarction.

Early decompressive surgery in malignant infarction of the middle cerebral artery: a pooled analysis of three randomised controlled trials

BACKGROUND

Malignant infarction of the middle cerebral artery (MCA) is associated with an 80% mortality rate. Non-randomised studies have suggested that decompressive surgery reduces this mortality without increasing the number of severely disabled survivors. To obtain sufficient data as soon as possible to reliably estimate the effects of decompressive surgery, results from three European randomised controlled trials (DECIMAL, DESTINY, HAMLET) were pooled. The trials were ongoing when the pooled analysis was planned.

METHODS

Individual data for patients aged between 18 years and 60 years, with space-occupying MCA infarction, included in one of the three trials, and treated within 48 h after stroke onset were pooled for analysis. The protocol was designed prospectively when the trials were still recruiting patients and outcomes were defined without knowledge of the results of the individual trials. The primary outcome measure was the score on the modified Rankin scale (mRS) at 1 year dichotomised between favourable (0-4) and unfavourable (5 and death) outcome. Secondary outcome measures included case fatality rate at 1 year and a dichotomisation of the mRS between 0-3 and 4 to death. Data analysis was done by an independent data monitoring committee.

FINDINGS

93 patients were included in the pooled analysis. More patients in the decompressive-surgery group than in the control group had an mRS<or=4 (75%vs 24%; pooled absolute risk reduction 51% [95% CI 34-69]), an mRS<or=3 (43%vs 21%; 23% [5-41]), and survived (78%vs 29%; 50% [33-67]), indicating numbers needed to treat of two for survival with mRS<or=4, four for survival with mRS<or=3, and two for survival irrespective of functional outcome. The effect of surgery was highly consistent across the three trials.

INTERPRETATION

In patients with malignant MCA infarction, decompressive surgery undertaken within 48 h of stroke onset reduces mortality and increases the number of patients with a favourable functional outcome. The decision to perform decompressive surgery should, however, be made on an individual basis in every patient.

Clinical review: Therapy for refractory intracranial hypertension in ischaemic stroke

The treatment of patients with large hemispheric ischaemic stroke accompanied by massive space-occupying oedema represents one of the major unsolved problems in neurocritical care medicine. Despite maximum intensive care, the prognosis of these patients is poor, with case fatality rates as high as 80%. Therefore, the term 'malignant brain infarction' was coined. Because conservative treatment strategies to limit brain tissue shift almost consistently fail, these massive infarctions often are regarded as an untreatable disease. The introduction of decompressive surgery (hemicraniectomy) has completely changed this point of view, suggesting that mortality rates may be reduced to approximately 20%. However, critics have always argued that the reduction in mortality may be outweighed by an accompanying increase in severe disability. Due to the lack of conclusive evidence of efficacy from randomised trials, controversy over the benefit of these treatment strategies remained, leading to large regional differences in the application of this procedure. Meanwhile, data from randomised trials confirm the results of former observational studies, demonstrating that hemicraniectomy not only significantly reduces mortality but also significantly improves clinical outcome without increasing the number of completely dependent patients. Hypothermia is another promising treatment option but still needs evidence of efficacy from randomised controlled trials before it may be recommended for clinical routine use. This review gives the reader an integrated view of the current status of treatment options in massive hemispheric brain infarction, based on the available data of clinical trials, including the most recent data from randomised trials published in 2007.