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06 anastomotic concept and anastomosis

Rat femoral arteriovenous fistula model anastomotic concept and anastomosis

07.06 Rat Femoral Arteriovenous Fistula Model Anastomotic concept and anastomosis

Arteriovenous fistula – anastomotic concept

In this example we will be placing 12 stitches with 10.0 suture. More or fewer stitches may be necessary, depending on the preparation of the vessels.
Stitches one and two are placed 180 degrees apart, here and here. Rather than parallel to each other, the remaining stitches are placed in a radial fashion from the center of the artery. Once the anterior wall is sutured, the vessels are be flipped over and the posterior wall is sutured the same way.


Arteriovenous fistula – anastomosis

The microscope is set at a relatively high magnification.
The first stitch is placed right at the angle between artery and vein, as this angle becomes harder to access once the vessels are tied together.
When closing knots be especially careful to avoid tearing either vessel wall. Bear in mind that the venous wall is more fragile than that of the artery and that tension in this model cannot be assumed to be distributed evenly across both cut edges.
Place the second stitch 180 degrees from the first. Be sure to provide sufficient counter-pressure while passing the needle through the vessel walls in order not to pull on the first knot.
Now that the vessels are both fixed in space, it is easier to suture the anterior wall. Here, we will be using five stitches. Before placing them probe once more to verify their positions and to avoid uneven distribution of the vessel circumferences along the suture line commonly referred to as a “dog-ear”. Then place the third stitch midway between the first two. Place stitches four and five and stitches six and seven in pairs.
Once the anterior wall has been completed, flip over the approximator and check for potential backstitches.
The posterior wall is sutured in a similar manner, placing stitch number eight midway between the first two.
Here is the finished end-to-side anastomosis.