TO THE EDITOR: We read with great interest the timely and provocative article by Berro et al.,1 an exciting work that provides important and novel evidence in support of the conclusion that middle cerebral artery (MCA) aneurysms are and should remain surgical lesions (Berro DH, L’Allinec V, Pasco-Papon A, et al: Clip-first policy versus coil-first policy for the exclusion of middle cerebral artery aneurysms. J Neurosurg [epub ahead of print September 20, 2019. DOI: 10.3171/2019.5.JNS19373]).
By leveraging established “clip first” and “coil first” protocols at sister institutions, applied to paired series of consecutive patients, the authors have executed a clever study design that functions as a form of surrogate randomization. The benefits of this approach are apparent in the “intention-to-treat” analysis, which provides real-world data that allow practical conclusions to be drawn within a relatively rigorous statistical framework.
The authors have posed the question, “Does an institution that practices a clip-first policy achieve superior clinical outcomes to one that practices under a coil-first policy, allowing for clinically determined crossover between techniques in rare, appropriately selected circumstances?”
The answer is a compelling yes, supported in their study by evidence with a higher degree of reliability and certainty than essentially all preceding observational studies and in alignment with the highest-quality evidence from clinical trials in this space—including the Barrow Ruptured Aneurysm Trial (BRAT).3–5
The study also highlights two vulnerabilities of endovascular coiling as a primary modality for MCA aneurysms. First, the alarmingly low rate of complete radiographic occlusion in the endovascular group (31%) demonstrates that a large fraction of patients with coiled MCA aneurysms remain exposed to an unacceptable risk of rupture or rebleeding. Additionally, patients who underwent coiling were also significantly more likely to require retreatment and were therefore subject to the intrinsic risks of two procedures, the second of which was markedly higher risk, as a repeat intervention.
Although neurosurgery is evolving beyond rigid “clip/coil first” policies, we have learned that the safer default treatment for patients with MCA aneurysms is clipping. As such, the findings reported by Berro et al. provide a key ballast against the concerning trend we have noted—particularly in Europe—of centers adopting universal coil-first postures toward intracranial aneurysms, independent of location, morphology, or other predictive factors. This attitude is informed in part by a 2018 Cochrane review, which argued that patients with favorable hemorrhage grades should preferentially undergo coiling. Unfortunately, the evidence-based analysis reproduces the intrinsic limitations and biases of its component studies—namely, that the granularity between patient cohorts (e.g., MCA location) is inadequate.2 This vulnerability is highlighted by numerous other analyses, such as single-center studies, clinical trials including the BRAT, and at least 2 other large-scale systematic reviews that appropriately stratified cases by aneurysm location, all of which highlighted key outcomes in clinical, radiographic, or durability domains that support the superiority of neurosurgical clipping for the treatment of MCA aneurysms.3,5–7
We congratulate the authors for their outstanding work, which demonstrates a creative and compelling mode for infusing clinical research in neurosurgery with additional rigor and reinforces the fundamental superiority of open clipping for MCA aneurysms.
Disclosures
The authors report no conflict of interest.
References
- 1↑
Berro DH, L’Allinec V, Pasco-Papon A, Emery E, Berro M, Barbier C, : Clip-first policy versus coil-first policy for the exclusion of middle cerebral artery aneurysms. J Neurosurg [epub ahead of print September 20, 2019. DOI: 10.3171/2019.5.JNS19373]
- 2↑
Lindgren A, Vergouwen MDI, van der Schaaf I, Algra A, Wermer M, Clarke MJ, : Endovascular coiling versus neurosurgical clipping for people with aneurysmal subarachnoid haemorrhage. Cochrane Database Syst Rev 8:CD003085, 2018
- 3↑
Mooney MA, Simon ED, Brigeman S, Nakaji P, Zabramski JM, Lawton MT, : Long-term results of middle cerebral artery aneurysm clipping in the Barrow Ruptured Aneurysm Trial. J Neurosurg 130:895–901, 2018
- 4
Spetzler RF, McDougall CG, Zabramski JM, Albuquerque FC, Hills NK, Nakaji P, : Ten-year analysis of saccular aneurysms in the Barrow Ruptured Aneurysm Trial. J Neurosurg [epub ahead of print March 8, 2019. DOI: 10.3171/2018.8.JNS181846]
- 5
Spetzler RF, Zabramski JM, McDougall CG, Albuquerque FC, Hills NK, Wallace RC, : Analysis of saccular aneurysms in the Barrow Ruptured Aneurysm Trial. J Neurosurg 128:120–125, 2018
- 6
Steklacova A, Bradac O, Charvat F, De Lacy P, Benes V: “Clip first” policy in management of intracranial MCA aneurysms: single-centre experience with a systematic review of literature. Acta Neurochir 158:533–546, 2016
- 7
Zijlstra IA, Verbaan D, Majoie CB, Vandertop P, van den Berg R: Coiling and clipping of middle cerebral artery aneurysms: a systematic review on clinical and imaging outcome. J Neurointerv Surg 8:24–29, 2016
