Rat femoral arteriovenous fistula model preparation of the vessel ends

Preparation of the vessel ends

The artery is cut at a safe distance from the ligature, to keep the suture from sliding off the vessel stump. Irrigate the artery right away. If necessary, brush out the long vessel stump with the smooth outer edge of an instrument. Perform the adventitiectomy. Dilate the vessel, placing the vasodilator sufficiently deep into its lumen. Probe at which point you can reach the side of the venous wall with the cut arterial end without exerting stretch on the artery. At this point, place a small stay stitch through the whole thickness of the vessel wall. Tie its knot, leave one end long and pull up on it to form a small tent. Cut the tent out with curved scissors. Irrigate the vein and brush remaining blood out with the smooth outer edge of an instrument. After removing the clouded liquid, submerge the vein once more to keep its walls from sticking to each other. The cut should be about one and a half times as long as the round arterial vessel-end. In the following step, the artery is cut at about 45 degrees from its cut edge along this line. In this case you can firmly grasp the entire thickness of the vessels portion, which will be removed, at one point or in an oblique line running across the vessel, to immobilize it while cutting.

Preparation of the vessel ends – pitfalls, tips and tricks

If the cut in the vein is too long to match the cut on the artery you can adjust the cut on the artery accordingly. Bear in mind that a steeper angle between the vessels may negatively affect the dynamics of flow inside the fistula. If the cut in the vein is too short to match the cut on the artery you can elongate the cut in the vein on either side. However, you have to be perfectly accurate to end up with a good result. Finally, fix the arterial wall in space by grasping its full thickness on its side facing the vein and cut the vessel stump in the designated line. Open up the vessel stump and perform the adventitiectomy.