As the development and testing of endovascular devices in intracranial aneurysm treatment is still greatly needed. We have designed a novel arterial pouch bifurcation model in rabbits. This model uses a single, highly standardized and easily reproducible microsurgical technique to create a autologous material pouch bifurcation aneurysms with modified and non-modified wall conditions in rabbits.
After confirming a lack of response to pedal reflex in an anesthetized adult rabbit, make a median skin incision from the manubrium sterni to the level of the larynx, and use a scalpel, surgical scissors, and forceps to sharply dissect the skin and soft tissue. Using micro forceps and surgical scissors, enter the anterior upper ridge of the sternocleidomastoid muscle immediately on the left side by blunt dissection. And macroscopically perform a blunt preparation to carefully distally separate the left common carotid artery from the vagal nerve to avoid laryngeal paresis.
Administer 40 milligrams per milliliter of papaverine locally into the artery and position the papaverine soaked artery below the autologous muscle tissue to protect the vessel from dehydration under the light of the surgical microscope. Switch sides and perform the same dissection on the right side of the animal as just demonstrated. When the right common carotid artery has been isolated inject 500 international units per kilogram of heparin systemically via a venous ear catheter.
After tightening the six zero ligature, use a temporary vessel clip to clamp the right common carotid artery as far distally as possible to avoid endothelial damage, to create a long vessel segment for irrigation to prevent thrombogenesis. To harvest the pouch, cut the distal vessel to the four zero nonabsorbable ligature. Then cut the vessel distal to the 6-0 non-absorbable ligature.
Meticulously clean the arterial pouch of all soft tissue and use a vessel clip to measure the length, width, and depth of the pouch. If a pouch degradation is needed, pre-incubate the cleaned pouch with 100 units of porcine elastase dissolved in five milliliters of Tris buffer at room temperature for 20 minutes. For further preparation of the common carotid artery, place two micro swabs directly beneath the common carotid artery to allow the vessel to be moved superficially and place an additional micro swab with a blue padding under the left artery at the distal third for better visualization of the artery.
Change sides to access the left side of the animal and use micro scissors and forceps to make a two millimeter fish mouth incision on the proximal side of the right common carotid artery. Use the second temporary vessel clip to clamp the left distal common carotid artery and clamp the proximal left common carotid artery with two additional temporary vessel clips. When all of the clamps have been placed, liberate the distal third of the left common carotid artery completely from the soft tissue and perform an arteriotomy.
Now flush the recipient vessel with heparinized saline and liberate the complex from a adventitia, then suture the right common carotid artery to the left common carotid artery. Transfer the arterial pouch from the heparinized saline solution into the surgical field where the bifurcation is planned. While keeping all of the aspects of the vessel complex hydrated with a continuous saline irrigation, suture the pouch to the vessel, and then remove all of the temporary vascular clamps in stepwise manner.
When all of the clamps have been removed, administer one milliliter of fluorescein intravenously to perform fluorescence angiography of the vessel complex. Then close the operative situs according to standard protocols. In this experimental analysis, animals with aneurysms induced by either the vital or elastase pouch methods demonstrated an increase in aneurysm size over time.
The average duration of the surgical procedure for the control group was 164 plus or minus 10 minutes compared to 201 plus or minus 13 minutes for the modified group. An average of 24 plus or minus one interrupted sutures was needed to create aneurysms in the controlled group, while 25 plus or minus two stitches were required in the elastase group. Measurements can then be performed by using three dimensional reconstructions of the MR imaging and detailed histological analysis.
A careful separation of the common carotid artery from the vagal nerve is essential for avoiding postoperative complications. To avoid thrombogenesis, keep the vessel and arterial pouch complex hydrated. Given the excellent patiency achieved with aneurysm growth over time, this model may serve as an important tool for the preclinical evaluation of novel endovascular devices.
