Apr 2016 / Vol. 124 / No. 4 / Pages 1130-1133
Letter to the Editor: Last call for clipping aneurysms?
TO THE EDITOR: With the publication of the most recent results of the Barrow Ruptured Aneurysm Trial (BRAT),3 we would like to take the opportunity to comment on the accompanying editorial1 and the authors’ response to clarify some misconceptions about other trials such as the International Subarachnoid Aneurysm Trial II (ISAT II) (Spetzler RF, McDougall CG, Zabramski JM, et al: The Barrow Ruptured Aneurysm Trial: 6-year results. J Neurosurg 123:609–617, September 2015; Macdonald RL: Editorial. Clip or coil? Six years of follow-up in BRAT. J Neurosurg 123:605–608, September 2015). We must radically change the way we practice to enter the era of outcome-based neurovascular care.
The editorial analysis of the BRAT trial report and the authors’ response raise two major concerns: 1) that open-surgery expertise is declining as practices convert from open to endovascular approaches; and 2) that the limitations of clinical trial methodology (any trial) make it unlikely that reliable answers to clinical questions can be obtained in a timely fashion.
The answers we are given to both problems are suffused with hopelessness: “Advocates of neurosurgical clipping of ruptured aneurysms are fighting an increasingly uphill battle with fewer and fewer troops.”1 Furthermore: “It would be most unfortunate for clinical equipoise to be lost solely because open-surgery skills generally fell into decline.”1 As to trials, we learned that “Sufficient questions remain regarding the relative benefits of the 2 treatment modalities to warrant further well-designed randomized trials,” but the same authors also wrote: “Nor does ISAT II seem well positioned to fill this void any time soon.”1
Let’s first address the problem with trials. In both the editorial and the authors’ response, as in the received view, trials are conceived as experiments performed to provide answers to research questions. Clinicians are expected to modify their practice according to the results of trials performed decades earlier or to make a treatment recommendation for their next aneurysm patient, even when no one really knows what to do. Let’s see why this system cannot work, and how it could be fixed.
The BRAT and ISAT investigations involved patients recruited 8–20 years ago (ISAT recruited from 1994 to 2002; BRAT, from 2003 to 2007). Since then, what have we been doing? This question encompasses not only our research activities (still meager considering the amount of work to do) but also how we have been caring for patients. If we have allowed ourselves to make treatment recommendations despite uncertainty for 20 years, is it surprising that we are now reluctant to give up our opinions according to results of trials performed so long ago?
The gulf created by clinical research conceived as an activity separated from the very clinical practice it is supposed to inform must be corrected. The burning question, “Should I offer open or endovascular treatment for this patient?” involves serious uncertainty. It should impact practice, the way we should care for that very patient, immediately. The change in practice cannot wait for an answer. BRAT was a step in the right direction, but why was it stopped? We need outcome-driven practices, but they can only be secured after we have learned to rightly practice under uncertainty, using proper trials, until better outcomes are actually shown. Not all trials live up to this calling, and there is no room here to rehearse the needed methodology, which we have explained elsewhere.2 In short, neurosurgical trials can be designed to offer, in real time, optimal care in the presence of uncertainty.2
Trials such as ISAT II can also address the first concern of losing open-surgical skills: open surgery is neither crowned as “best forever” nor abandoned without good reason; it is offered and performed in 50% of cases, until it is shown to be superior (in which case it is prescribed, rather than randomly allocated) or inferior (in which case the alternative treatment is prescribed).
Who should be treated within ISAT II? If you consider clipping an aneurysm in a particular patient despite Level I evidence that coiling is in general better, you should rather offer the patient a 50% chance of receiving clipping and a 50% chance of receiving endovascular treatment. If you consider endovascular treatment for the types of patients who or aneurysms that were not included in ISAT, or using devices that were not available at the time of ISAT or BRAT, this should be considered experimentation, which should be offered only as a 50% chance of getting the innovative treatment, and a 50% chance of getting surgical clipping.
As the senior generation of neurosurgeons, many of them luminaries, hands over the reins to up and coming, fully trained open-surgery neurovascular surgeons, some with dual endovascular training, the thing to abandon is not surgical clipping—it is, rather, this outdated habit of practicing unverifiable care forever. This applies not only to ruptured aneurysms (ISAT II may very well turn out to be a “last call” for practicing and eventually having a chance to demonstrate the merits of surgical clipping), but also to arteriovenous malformations, unruptured aneurysms, and almost all domains of neurovascular care. Medical care is in constant evolution, and innovative ways to care for patients are constantly challenging the notion of standard care. We must discipline ourselves to learn how to practice in such a context, reliably sorting out what practice provides the best clinical results in real time, with care trials such as ISAT II.
1.Macdonald RL: Editorial. Clip or coil? Six years of followup in BRAT. J Neurosurg 123:605–608, 2015 Link
3.Spetzler RF, McDougall CG, Zabramski JM, Albuquerque FC, Hills NK, Russin JJ, et al.: The Barrow Ruptured Aneurysm Trial: 6-year results. J Neurosurg 123:609–617, 2015 Link
Drs. Darsaut and Raymond report being Principal Investigators of the ISAT II study (which did not receive any funding).
- Jean Raymond, Tim E. Darsaut, David J. Roy. (2017) Recruitment in Clinical Trials: The Use of Zelen’s Prerandomization in Recent Neurovascular Studies. World Neurosurgery 98, 403-410. . Online publication date: 1-Feb-2017. [CrossRef]