Microsurgery Essentials: Suturing
How to Suture (Step-by-Step)
4 step process on the basics of microsurgial suturing as demonstrated on a latex model.
1. Picking up the Needle
At first, grasping the needle is difficult because it will have a tendency to want to jump around. What can oftentimes help is to get hold of the thread with the left-hand forceps at a point 2 to 3 cm away from the needle. Dangle the needle until it just comes to rest on the surface. This will then allow you to use the angulated needle holder to grab the needle easily.
Your needle is in a stable position if it is set up to 90 degrees to the axis of the tips of the forceps. You can make minor corrections by touching the needle with your left-hand forceps, or by partially relaxing your grip and nudging the needle tip against another firm object.
You should hold the needle just behind its midpoint (If you hold it too near the tip, it will point downward. If you hold it too near the thread end, it will point upward.).
2. Passing the Needle Through
The needle should pass through the tissue at a perpendicular.
Place the tips of the left-hand forceps on the underside of the tissue at the point where the needle will enter, and gently push the edge upward. With the right hand, bring the needle into contact with the tissue, and press downward. These movements create eversion. Pass the needle through. Do not grab the tissue with your left hand forceps since it will damage the intima. If needed, you can pick up adventitia or a nearby suture to help with exposure and eversion.
The needle must pass through the other side at a perpendicular, too. Bring the tip of the needle to the place where you intend to bring it out on the other side. Put the tip of your left-hand forceps on the upper surface of the tissue at the intended exit point. Press down with the left-hand forceps and push up with the needle to give you the correct eversion. The width of the bite should be about three times the thickness of the needle. The bites on both sides must be equal, and the needle should cross exactly in a straight line (not diagonally). Pull the needle through the tissue following the curve of the needle.
NOTE: When operating on a vessel, the STAY sutures should be placed in 2 passes, while all other sutures are placed in 1 pass. As a beginner, it may be easier to do it in 2 passes. Try practicing both ways.
3. Pulling the Suture Through
Use the tip of the right-hand needle driver as a guiding pulley when pulling the needle through.
Keep the suture parallel to the direction of the entry-exit line. Leave about a 3-mm tail.
4. Tying the Knot
i. Pick up thread with left hand forceps:
Grab suture about 1 cm from incision site with left hand. Make sure the part that you are going to tie with comes out from the side of the forceps that is toward you.
ii. Make a loop:
Turn the suture into a loop around the tip of the needle holder. Make the loop close to the short end tail.
iii. Pick up the short end:
If the end is too short, pull it out longer. Grab it with your right hand needle holder.
iv. Complete the knot:
Once you’ve picked up the short end, pull it through the loop with the needle holder. Allow the loop to fall off the tip of the needle holder, and your first knot is done. Do NOT let go of the suture with your left hand. Repeat steps 2 through 4 to complete the second and third knots. Make sure the knots are squared.
NOTE: When operating on a vessel, the first throw of the STAY suture is a surgeon’s knot, while all other knots are single throws. Try practicing both ways.
Now cut the short end of the suture first, and discard it. Then hold on to the long suture and cut it close to the knot. Pull on the long thread, and the needle will come into view, and you’re ready for your next stitch.