The Helsinki Rat Microsurgical Sidewall Aneurysm Model

Abstract

Experimental saccular aneurysm models are necessary for testing novel surgical and endovascular treatment options and devices before they are introduced into clinical practice. Furthermore, experimental models are needed to elucidate the complex aneurysm biology leading to rupture of saccular aneurysms.Several different kinds of experimental models for saccular aneurysms have been established in different species. Many of them, however, require special skills, expensive equipment, or special environments, which limits their widespread use. A simple, robust, and inexpensive experimental model is needed as a standardized tool that can be used in a standardized manner in various institutions.The microsurgical rat abdominal aortic sidewall aneurysm model combines the possibility to study both novel endovascular treatment strategies and the molecular basis of aneurysm biology in a standardized and inexpensive manner. Standardized grafts by means of shape, size, and geometry are harvested from a donor rat's descending thoracic aorta and then transplanted to a syngenic recipient rat. The aneurysms are sutured end-to-side with continuous or interrupted 9-0 nylon sutures to the infrarenal abdominal aorta.We present step-by-step procedural instructions, information on necessary equipment, and discuss important anatomical and surgical details for successful microsurgical creation of an abdominal aortic sidewall aneurysm in the rat. Video LinkThe video component of this article can be found at

Flow diverter implantation in a rat model of sidewall aneurysm: a feasibility study

“…We used 72 6–8-week-old Wistar WU rats (Charles River, Den Bosch, The Netherlands) for this experiment. A thoracic aorta segment was harvested from 36 rats and was subsequently decellularized by the method previously described 8. The decellularized aortic segment was used to create a microsurgical aneurysm in the abdominal aorta of 36 recipient rats.…”

“…A thoracic aorta section between the first intercostal artery and the left subclavian artery was harvested according to the method described by Marbacher et al 8 (figure 1). After harvesting, the tissue was immediately stored in an Eppendorf tube filled with phosphate buffered saline (PBS) and stored on ice until decellularization overnight.…”

“…Decellularization of the aneurysm wall was achieved by incubation for 10 hours at 37°C in a 0.1% sodium dodecyl sulfate (SDS) in milli-Q water solution, identical to the protocol of Marbacher et al 8. After decellularization, the tissue was stored on ice in an Eppendorf tube filled with PBS until surgery later that day.…”

“…This model is exceptional among the available in vivo aneurysm models in that aneurysm growth and even rupture have been documented 9. Expansion of the rat sidewall aneurysm model for experiments with endovascular devices, such as FDs, has been suggested by Marbacher et al ,8 but has not been demonstrated up to this point. The goal of this study is to investigate the feasibility of expanding the sidewall aneurysm rat model as a tool for testing FDs.…”

“…Recently, a possible candidate for a new and challenging model has been introduced by Marbacher et al 8. In this model a thoracic aorta segment from a donor rat is decellularized and implanted in the abdominal aorta of a recipient rat.…”