Trial on endovascular treatment of unruptured aneurysms (TEAM): study monitoring and rationale for trial interruption or continuation

The prevention of hemorrhagic stroke. A review of the rational and ethical principles of clinical trials on unruptured intracranial aneurysms and arteriovenous malformations

SUMMARY

There is currently no evidence that preventive treatment of unruptured aneurysms or AVMs is beneficial and randomized trials have been proposed to address this clinical uncertainty. Participation in a trial may necessitate a shift of point of view compared to a certain habitual clinical mentality. A review of the ethical and rational principles governing the design and realization of a trial may help integrate clinical research into expert clinical practices. The treatment of unruptured aneurysms and AVMs remains controversial, and data from observational studies cannot provide a normative basis for clinical decisions. Prevention targets healthy individuals and hence has an obligation of results. There is no opposition between the search for objective facts using scientific methods and the ethics of medical practice since a good practice cannot forbid physicians the means to define what could be beneficial to patients. Perhaps the most difficult task is to recognize the uncertainty that is crucial to allow resorting to trial methodology. The reasoning that is used in research and analysis differs from the casuistic methods typical of clinical work, but clinical judgement remains the dominant factor that decides both who enters the trial and to whom the results of the trial will apply. Randomization is still perceived as a difficult and strange method to integrate into normal practice, but in the face of uncertainty it assures the best chances for the best outcome to each participant. Some tension exists between scientific methods and normal practice, but they need to coexist if we are to progress at the same time we care for patients.

The TEAM trial: safety and efficacy of endovascular treatment of unruptured intracranial aneurysms in the prevention of aneurysmal hemorrhages: a randomized comparison with indefinite deferral of treatment in 2002 patients followed for 10 years

The management of patients with unruptured aneurysms remains controversial. Patients with unruptured aneurysms may suffer intracranial haemorrhage, but the incidence of this event is still debated; endovascular treatment may prevent rupture, but involves immediate risks. Hence, the balance of risks and benefits of endovascular treatment is uncertain. Here, we report the design of the TEAM trial, the first international, randomized, controlled trial comparing conservative management with endovascular treatment. Primary endpoint is mortality and morbidity (modified Rankin Score >/= 3) from intracranial haemorrhage or treatment. Secondary endpoints include incidence of hemorrhagic events, morbidity related to endovascular coiling, morphological results, overall clinical outcome and quality of life. Statistical tests compare between probabilities at 5- and 10-years of 1) mortality from haemorrhage related to the lesion, excluding per-operative complications; 2) mortality from haemorrhage or from complications of treatment; 3) combined disease or treatment related mortality and morbidity in the absence of other causes of death or disability. The study will be conducted in 60 international centres and will enroll 2,002 patients equally divided between the two groups, a size sufficient to achieve 80% power at a 0.0167 significance to detect differences in 1) disease or treatment-related poor outcomes from 7-9% to 3-5%; 2) overall mortality from 16 to 11%. Duration of the study is 14 years, the first three years being for patient recruitment plus a minimum of 10 years of follow-up. The TEAM trial thus offers a means to reconcile the introduction of a new approach with the necessity to acknowledge uncertainties.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN62758344 http://www.controlled-trials.com.

ICONE: An International Consortium of Neuro Endovascular Centres

SUMMARY

The proliferation of new endovascular devices and therapeutic strategies calls for a prudentand rational evaluation of their clinical benefit. This evaluation must be done in an effective manner and in collaboration with industry. Such research initiative requires organisation a land methodological support to survive and thrive in a competitive environment. We propose the formation of an international consortium, an academic alliance committed to the pursuit of effective neurovascular therapies. Such a consortium would be dedicated to the designand execution of basic science, device developmentand clinical trials. The Consortium is owned and operated by its members. Members are international leaders in neurointerventional research and clinical practice. The Consortium brings competency, knowledge, and expertise to industry as well as to its membership across aspectrum of research initiatives such as: expedited review of clinical trials, protocol development, surveys and systematic reviews; laboratory expertise and support for research design and grant applications to public agencies. Once objectives and protocols are approved, the Consortium provides a stable network of centers capable of timely realization of clinical trials or pre clinical investigations in an optimal environment. The Consortium is a non-profit organization. The potential revenue generated from clientsponsored financial agreements will be redirected to the academic and research objectives of the organization. The Consortium wishes to work inconcert with industry, to support emerging trends in neurovascular therapeutic development. The Consortium is a realistic endeavour optimally structured to promote excellence through scientific appraisal of our treatments, and to accelerate technical progress while maximizing patients' safety and welfare.

A Randomized Trial Comparing Platinum and Hydrogel-coated Coils in Patients Prone to Recurrence after Endovascular Treatment (The PRET Trial)

SUMMARY

New coils have been designed to preserve the safety of coil embolization while improving on long-term efficacy. There is currently no scientific evidence that one type of coil material is better than another. The recurrence problem may be more pressing in certain types of patients, such as patients with large aneurysms or those already presenting with angiographic recurrences.

[Critical analysis of the ISUIA study: the methodological point of view]

ISUIA is a prospective study that ran from 1991 to 1998 and included 4060 patients from 161 centers. Analysis of the methodology focused on: (1) sampling: inclusion was more intensive towards the end of the study period, which was likely to generate a selection bias; (2) a possible indication bias, as direct comparison between observation and treatment groups showed that patients receiving preventative treatment were more at risk of complications; (3) the statistical analyses, which never compared these groups directly, although that would have been the best approach for answering the research question. The size and site of aneurysm appear to be risk factors that were also never included in the multivariate analysis; (4) the outcome criteria, which were either not comparable (spontaneous rupture rate), not compared (disability rate) or presented in a non-comparable way (mortality rate by the Kaplan-Meier method versus raw estimates); (5) interpretation of the results, which should be made with caution as, with no statistical calculations provided, it is assumed that the risk of rupture is constant over time. In spite of the practical difficulties such a study would raise, only a randomized controlled comparison of strategies would offer a clear basis for improved clinical practices, given the fact that increasingly smaller aneurysms can now be identified.

Unruptured Intracranial Aneurysms. Opinions of Experts in Endovascular Treatment Are Coherent,Weighted in Favour of Treatment, and Incompatible with ISUIA

SUMMARY

In the absence of level one evidence, the treatment of unruptured intracranial aneurysms is grounded on opinions. Results of the largest registry available, ISUIA (the International Study on Unruptured Intraacranial Aneurysms) suggest that surgical or endovascular treatments are rarely justified. Yet the unruptured aneurysm is the most frequent indication for treatment in many endovascular centres. In preparation for the initiation of a randomized trial, we aimed at a better knowledge of endovascular expert opinions on unruptured aneurysms. We administered a standard questionnaire to 175 endovascular experts gathered at the WFITN meeting in Val d'Isère in 2007. Four paradigm unruptured aneurysms were used to poll opinions on risks of treatment or observation, as well as on their willingness to treat, observe or propose to the patient participation in a randomized trial, using six questions for each aneurysm. Opinions varied widely among lesions and among participants. Most participants (92.5%) were consistent, as they would offer treatment only if their estimate of the ten-year risk of spontaneous hemorrhage would exceed risks of treatment. Estimates of the natural history were consistently higher than that reported by ISUIA. Conversely, treatment risks were underestimated compared to those reported in ISUIA, but within the range reported in a recent French registry (ATENA). Participants were more confident in their evaluation of treatment risks and in their skills at treating aneurysms than in their estimates of risks of rupture entailed by the presence of the lesion, the latter being anchored at or close to 1%/year. The gulf between expert opinions, clinical practices and available data from registries persist. Expert opinions are compatible with the primary hypothesis of a recently initiated randomized trial on unruptured aneurysms (TEAM), which is a benefit of endovascular treatment of 4% compared to observation over ten years.Only data from a randomized trial could provide convincing objective evidence in favour or against preventive treatment of unruptured intracranial aneurysms.