As the first author (and the senior author) I am wholly responsible for any errors in the paper, including errors of attribution. I apologize first to our readers, and second to Dr. Altes, whose contributions are significant and are of continuing value.

Charles Kerber M.D.

Conflict of Interest:

None declared

Dear Editor,

I read with interest the paper by Kerber, et al. entitled "1-Hexyl n- cyanoacrylate compound (Neucrylate_AN), a new berry aneurysm treatment. II. Rabbit implant studies: technique and histology." (1) As suggested by the title, the paper focuses on the preclinical evaluation of a new device in a rabbit model. However, the references and discussion are misleading and may well confuse researchers intending to reproduce the authors' experiments.

The model used in the paper by Kerber, et al. is the widely-applied, elastase-induced aneurysm model originally published by Altes, et al (2). This simple model uses intraluminal elastase incubation to covert a preexisting arterial lumen, the right common carotid artery, into an aneurysmal stump. However, the methods of the paper by Kerber, et al. (1) reference a completely distinct and different model published by Miscolizik, et al (3). That latter model used extraluminal elastase applied to arterial bifurcations, with resultant aneurysms forming acutely but no chronic experiments described. Thus, readers of the paper by Kerber, et al. should be advised that the periadventitial model of Miskolczi, et al. was not, in fact utilized.

Further, the authors go on to note in their discussion that "In 1998, Miskolczi, et al. developed a rabbit aneurysm model that provided a close to ideal testing milieu for endovascular, particularly intra-arterial, devices." In fact, I am unable to find a single study that has used that the model of Miskolczi, et al. to test any device. Finally, Kerber, et al. write that "An extensive literature has accumulated since Miskolczi's original paper- a literature describing device behaviors and a wall response to the introduction of foreign devices." The "extensive literature" again has nothing to do with the paper by Miscolczi, but rather describes work done using the elastase-induced model of Altes, et al.

Clarity and precision are essential aspects of all medical literature, both clinical and preclinical. Accurate references to animal models will speed development of devices for the benefit of patients suffering from intracranial aneurysms.

References

1. Kerber CW, Pakbaz RS, Hasteh F, et al. 1-Hexyl n-cyanoacrylate compound (Neucrylate™ AN), a new berry aneurysm treatment. II. Rabbit implant studies: technique and histology. J Neurointerv Surg. 2012 Jan 1;4(1):50-7. Epub 2011 Jun 8.

2. Altes TA, Cloft HJ, Short JG, et al.. 1999 ARRS Executive Council Award. Creation of saccular aneurysms in the rabbit: a model suitable for testing endovascular devices. American Roentgen Ray Society. AJR Am J Roentgenol. 2000 Feb;174(2):349-54.

3. Miskolczi L, Guterman LR, Flaherty JD, et al. Saccular aneurysm induction by elastase digestion of the arterial wall: a new animal model. Neurosurgery. 1998 Sep;43(3):595-600; discussion 600-1.

Conflict of Interest:

Dr. Kallmes receives research support from MicroVention, Micrus, Penumbra, NFocus, Sequent, and eV3.