[[400 Technical Outline of Aortic Valve Replacement]] # Aortic Annular Sutures - Drape off the field of the aortic valve with four blue towels to isolate the annular sutures from cannulation stitches, clamps, tubing, "simplifying the field" - The aortic annulus drops in graceful curves from the high point of each commissure. The sewing ring of the prosthetic valve (particularly if mechanical) is mostly flat. Keep this in mind with the commissure stitches. - General pledgeted annular stitch principles[^a] - Use the full width of the pledgeted annular stitch - If tissue in an area is delicate, a slightly greater frequency of stitches can be employed - If an unexpected gap is left, a pledgeted stitch smaller than the width of the pledget may be necessary, and is not a problem. Just try to keep track of this in your head when it comes time to distribute the stitches into the sewing ring of the valve. - The pledgets will be on the ventricular side[^b] - Start with a general frequency of pledgets per cusp in mind, then see what happens - Smaller valves: One pledgeted stitch per commissure, three per cusp - Larger valves: One pledgeted stitch per commissure, four per cusp - Bicuspid valves: Will often have irregular cusp sizes, one quite large, one quite small. Keep using the full width of the pledget as a guide. For example, you may end up with a 3-4-5 between commissure stitch distribution. Don't worry, these can be redistributed without problems in a mechanical valve, and with only minor considerations (orientation of posts relative to ostia) in tissue valves.[^c] - The depth of the entry point into the subannular tissue relative to the annulus can vary as necessary within reason - To grab a bite of ventricular myocardium or aortomitral curtain on one side of an annular gap caused by debridement prior to taking a bite of aorta to close the gap (see figure label A) - To avoid a deep calcification that was not worth debridement (see figure label B) - To gather more substantial tissue in an area weakened by debridement. - The exit point must emerge a uniform, limited distance just above the annulus to prevent encroachment upon the coronary ostia - Keep conscious of the location of the coronary ostia at all times - Keep the space between the pledgeted stitches as small as possible without "william telling" the sutures, about a half a millimeter apart[^d] - With the completion of each annular stitch, the two suture ends must be slightly "see-sawed" to ensure there is free motion. If not, the pledget is twisted, and not lying down properly, which may interfere with [[Secure Aortic Valve Prosthetic Annular Sutures]]. Pull the pledget into view with a DeBakey, untwist, then pull it up against the annulus using the the needle ends. - ![[Annular Suture Illustration.jpg]] - Start with the three commissure stitches to assist in exposure - Forehand-forehand for the Non-Left commissure - The Left-Right commissure is often a combination of forehand (on the left side) and backhand (on the right side of the commissure), or is backhand-backhand - Right-Non commissure involves turning your body caudad along the patient, and overhand forehand-overhand forehand, or backhand-backhand. Conversely, these are easy forehand for a skilled assistant on the left side of the table. - The ventricular entry must be more careful here because of the conduction system (see figure label C)[^e] - As each commissure stitch is completed, the needle ends are secured and weighted with two hemostats to distinguish them from other annular stitches[^f] - Proceed with cusp annular stitches - Announce to the scrub nurse with as much time as possible the color and load of the next stitch ("Next is Green Forehand", "Next is White Backhand") - If in doubt, to save time, the scrub can have a stitch loaded with one forehand, one backhand end, and deliver the appropriate end to the surgeon, then changing the other end as required. - With completion of each stitch, secure the needle ends with a single hemostat, and distribute in orderly fashion on the blue towels draping the field[^f] - Commissure stitches, and each preceeding previously placed stitch can have traction applied with the tip of a DeBakey by surgeon or assistant close to the exit from the annulus to pull the next portion of annulus into better view for the next stitch. - Just try not to abrade the stitch too much with the teeth of the DeBakey so as to not weaken the suture - Start from left cusp, a series of forehands - If it is easy, the right cusp is performed backhand - It is MUCH easier to move to the other side of the table and perform these forehand, which can be carried through to near mid Non-coronary cusp. - The Non-coronary cusp is a series of overhand-forehands, or forehands. - If a valve requiring preparation with saline washing to remove glutaraldehyde is to be used, sizing can be done before the last two or three stitches are completed to save time - Not necessary if Inspiris valve or mechanical valve to be used. - Where there is awkward visualization of the annulus (particularly in the right cusp), the motion required is to enter the annulus from the ventricular side, pause halfway,, and pull the annular tissue into the LVOT. This tests the quality of the tissue while bringing the top of the annulus into view. Then the passage of the needle is continued to emerge just above the annulus. [^a]: Must pledgets always be used? Some do not, and use a figure of eight stitch in the annulus instead. This method is supposed to be particularly favorable to the hemodynamics of smaller tissue prosthetics. I have always used pledgets in every situation. [^b]: There used to be a dictum to place pledgets on the aortic side for a mechanical valve, and on the ventricular side for tissue valves. This was because if the suture was snapped when tying down a mechanical valve, it is difficult to secure the loose pledget, and very difficult to place a new stitch. I have a (admittedly awkward) method to place a new stitch in this situation. It is much less awkward to do these things inside a tissue valve. That said, ventricular pledgets are necessary for a suprannular position of a valve, which allows placement of the largest valve possible.As can be seen in aortic insufficiency, the aortic annulus can be extremely large, such that the diameter is larger than the largest available prosthetic. In this range of prosthetic diameter, the size of the working elements of the valve doesn't change, but the sewing ring gets larger. Here, it can be useful to place the annular stitches with the pledgets on the aortic side (the intrannular position). This can gather in the patulous annulus, reducing it to the size of the valve. In these situations, a root replacement is typically required. [^c]: See [[Placement of Annular Sutures through Aortic Valve Prosthetic Ring]] [^d]: "William Telling": passing a needle through the middle of a suture, most often, but incredibly not always, a braided suture. Can usually be remedied if detected, catastrophic if undetected. [^e]: It is the custom in my operating room for the most junior member of the team to bid the conduction system farewell when sutures are being placed in the vicinity of the Right-Non commissure. (Suggested script: "Goodbye, conduction system! We will miss you! It was great having you around!") Thus mollified, it is hoped that the Bundle of His will not take offense at the needles. [^f]: Annular suture caddies exist, and can keep the sutures organized and the procedure efficient. That said, the disposable ones are expensive, and the re-usable ones employ springs as in an Ankeney retractor to trap the sutures. The metal springs often wear out or are dented to uselessness by unseen brutes in the Sterile Processing department. ![[Suture Holder.jpeg]] https://www.annalsthoracicsurgery.org/article/0003-4975(96)00149-X/pdf