This study outlines a surgical model for inducing intimal hyperplasia in rabbits following vascular grafting. The methodology involves exposing the carotid artery, clamping it, and using a jugular vein graft to simulate conditions leading to graft failure.
Under extreme vascular damage, the length of an injured vessel may become inadequate for end-to-end ligation. To repair this damage, a vascular graft may be introduced. However, graft injury during the surgical process may trigger vascular cell accumulation within the intima or the innermost luminal layer, resulting in a condition known as intimal hyperplasia.
To generate an intimal hyperplasia research model, begin with a rabbit whose carotid artery is surgically exposed. Clamp the proximal and distal ends of the artery to obstruct the blood flow. Next, dissect the artery in the middle. The carotid artery tends to shrink, contracting its orifice.
Inject saline to dilate the arterial orifice and enable subsequent graft ligation.
Now, introduce a jugular vein graft with the endothelial layer exfoliated to expose the intima. Then, insert a catheter into the graft to induce a vascular wall injury. Remove the catheter and suture the graft end-to-end with the arterial segments. Finally, remove the clamps to observe pulsation in the vessel, indicating successful graft ligation.
To initiate intimal hyperplasia, suture the carotid artery at a branch point. This causes accumulation of smooth muscle cells, and other blood cells into the intima causing it to thicken. Progressive thickening of the intima, leads to narrowing of the graft lumen, causing the vascular graft to fail.
To interpose the carotid artery with the harvested jugular vein, expose a 20 to 30-millimeter segment of the ipsilateral carotid artery, and separate the artery carefully from the nearby vein and nerve. Ligate all of the branches of the exposed vein with a 4-0 silk suture, and intravenously administer 200 IU/kg of heparin sodium.
Clamp the proximal and distal ends of the artery with surgical rubber clamps, and cut the artery between the clamps. Inject normal saline into the incised carotid artery proximally and distally to distend the artery, and place the harvested vein near the artery to anastomose the vessel in a reversed end-to-end fashion.
To anastomose the proximal end of the vein to the distal end of the artery, place two anchor stitches of 8-0 polypropylene at the site and the opposite site. Add stitches to the upper side of the anastomosis line between the anchor stitches. Flip the artery and the vein graft upside down, and add stitches on the remaining part of the anastomosis line.
Next, remove the intravenous catheter from the vein, and clamp the vein graft proximally. Declamp the carotid artery distally, and observe whether the vein graft expands gradually. Using 8-0 polypropylene interrupted sutures, anastomose the distal end of the vein to the proximal end of the artery, and declamp the artery to check for bleeding from the anastomosis sites.
Finally, ligate the internal carotid artery with a 4-0 silk suture to simulate a poor runoff condition, and to facilitate intimal hyperplasia. Then, clean the wound with saline. Close the incision with 3-0 polyglactin 910 in layers, and allow the rabbit to fully recover with monitoring before returning the animal to its home cage.
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