Fashioning the vein

This is undertaken after checking for leaks, usually during initial cardioplegia delivery, or just before going on bypass.

The proximal end of the vein is held between the left thumb and index finger.

Cut the vein end obliquely to make a rhombus-hood using a Mcindoe scissors. Ensure the edges are clean off adventitia.

Cut the bottom of the hood longitudinally to enlarge the hood to cover the arteriotomy. A forward-Castro scissors may be necessary.

The vein is placed near the sternal edge without any syringe, to ensure that it is not accidentally dropped on the floor.

Identification of targets

Identification and positioning may be undertaken in a single move. Knowledge of the coronary angiogram targets and conduit quality/length are essential to plan the order of anastomoses to minimise cross-clamp time and manipulations.

During cardioplegia delivery, position the table according to the first anastomosis. After cardioplegia is delivered, vent on, empty the heart (using left hand). Use right hand to lift the heart to allow the left pronated palm to raise the heart completely out of the pericardium. Place two large wet swabs into the oblique sinus against the AV groove. Use a small dry swab to hold the apex.

Identify the LAD first, then the diagonals, OMs, and the PDA in a clockwise fashion, and decide how many and which vessels to target, enabling the length of conduits to be estimated. Start with the most distal targets (OM to diagonal). It is also useful to know whether it is the PDA or the distal RCA that will require grafting, to estimate the number of targets possible with the length of conduit.

Coronary arteries will track back to the aorta, whereas cardiac veins go towards the coronary sinus. The vessels may be felt for calcification, which may be cord-like indicating complete occlusion. Cardioplegia may be delivered to see the engorgement of the target vessel.

Positioning

Position the heart with a wet swab and the assistant’s hands.

For lateral wall/OM, the table is tilted towards the surgeon. Use the right hand to deliver the heart from the oblique sinus into the left hand. Place 2 large wet towels. Use a small swab to twist the heart to visualise and position the OM. The assistant uses their right thumb to push down (to allow the artery to bulge out slightly) and stabilise the heart in position.

For proximal right, place 1-2 large wet towels in the oblique sinus, use a small swab held by the assistant’s right index and middle finger on the anterior RV to retract the right AV groove into the surgical field and keep the coronary stretched.

For PDA, place 1 large wet towel in the oblique sinus, and pull the inferior part of the towel up to twist the heart superiorly. The assistant uses their right index and middle finger on the inferior RV to retract the inferior interventricular groove into view.

For LIMA/diagonals, place 2 wet towels in the leftward oblique sinus should bring the vessel into view. For diagonal, the assistant may need to retract the ventricle away using their left index/middle finger.

Coronary arteriotomy

Retract the epicardial fat symmetrically about the intended coronary arteriotomy. Lift (one side up, one side away) the tissue to avoid cutting into the back wall. Ensure retraction is symmetrical for an arteriotomy parallel to the artery.

Use the tip of the 11-blade (straight) scalpel to stroke open the epicardial fat and the artery itself.

Use forward-Castro and reverse-Castro to cleanly cut the edges of the artery. For distal right and PDA, 90-degree Castro is used.

Place the eyelid retractor around the coronary vessel (using two forceps), placing one hook first and then the other. Ensure the retraction is adequate, and does not catch any other vessels. Cover the end of the retractor with a small swab, or the remainder of the large swab. 

Coronary anastomosis

For left-sided targets and the distal RCA, the assistant holds the vein in their right hand on the superior side of the field; for right-sided targets, the vein is held in the left hand on the inferior side for PDA. 

The assistant holds the top of the hood with ring-tip forceps stably on the superior part of the sternal retractor for left sided grafts, and on the inferior part of the retractor for right-sided grafts. It is held at the same level as the target, or slightly behind the suturing to allow for the suture to kept away from the artery. 

Double-ended [7-0 prolene for all distals, except 8-0 for LIMA-LAD] mounted on Castro-viejo needle-holder with rubber-shod bulldog on other needle.

The first bite on the vein is taken at its 5 o’clock position (12 being the non-cut part of the vein and 6 being the site of the longitudinal cut) from outside to inside with a forehand (or backhand) stroke. After passing through the vein, re-grip the needle in a backhand stroke ready for the next bite on the coronary artery.

The suture is pulled through and the rubber-shod lodged under the retractor.

The first bite on the coronary artery (cor) is taken at its 2-3 o’clock position (12 being the proximal coronary and 6 being the distal coronary) from inside to outside with a backhand stroke. Move the tip within the artery to ensure it is not catching the backwall.

The suture is left loose as the bites are taken in the vein (out-to-in VOI) and coronary (in-to-out CInO): [5 o’clock vein – out to in – forehand, 1 o’clock cor – in to out – forehand, 6 o’clock vein – out to in – forehand, 12 o’clock cor – in to out – forehand, 7 o’clock vein – out to in].

In the case of the PDA, the bite is first taken on the vein in the 7 o’clock position, followed by the artery in the 5 o’clock position, in a crossed manner. When parachuting the vein down, it is important to hold the vein in the correct heel-toe axis above all the sutures due to the crossed manner.

At the heel and toe, ensure the bite width is good, but the sutures may be closer together. The adventitia can be used to strengthen the suture line, but not if it is too far apart.

Parachute the vein down to the coronary at its 7 o’clock position, by using the forceps to pull the vein up and down, and the needleholder to pull one end of the suture. The other end is kept shorter, and taut and placed opposite.

Pull the vein edge taut to prevent any folding, and pass the needle through the vein. Visualise the tip of the needle before passing through the artery. Keep going around, this time taking bite simultaneously in both the vein and artery (out to out).

Needle passes – back-hand until just after 12 o’clock on the artery then fore-hand until just around 6 o’clock on the artery, then back hand keeping the vein still.

Tying the anastomosis

After going just beyond the first suture on the vein, cut one needle off (the one on the artery). Pull the suture to minimise any leaks, while distend the vein just before making the knot to avoid purse-stringing. Distend the vein after making the knot to check for leaks.

Ensure vein is not kinked/twisted by bands.

Fix any leaks by horizontal mattress sutures with conduit to artery bites.

If suture breaks, make a judgement as to how many knots have been placed already before breaking. If any doubt, unravel the suture to get a decent length, get a new suture, close the gap and use instrument tie with plenty of saline for lubrication.

After satisfied with anastomosis, keep the vein lifted up, remove the eyelid retractor and the large swabs letting the heart back into the pericardial well. Fill the heart, distend the vein, place the vein in the appropriate place (AV groove for OM, around PA for diag, anterior to RA for distal right and PDA), and correct for any longitudinal twist. Occlude the vein near the aorta to note the distension pattern, and note the length. Cut the vein obliquely in the heel-toe axis. Make the longitudinal slits in cut ends (one for the top-end, one for the next bottom-end). Empty the heart. Place the swabs back in the cavity while moving the table to the right position for the next anastomosis.

LIMA-LAD

Make a superior-inferior longitudinal slit in the pericardium (in a relatively translucent area), enlarge it inferiorly and posteriorly. Cauterise any vessels in pericardial/pleural fat. This may be done even before the anastomosis.

Bring out the LIMA (and the swab with any bulldogs). Let it rest on the surface of the heart, and correct for any twists. Cut the end (to remove any ligaclips) and check the flow. Once the orientation is checked, cut off any excess length. Using the left hand, place a bulldog near the base to occlude the flow. Lift up the LIMA pedicle and clip it with a mosquito (with the right hand) on the edge of the towel.

Ring-tips and large Potts 90 to strip the fascia on the LIMA precisely in the midline. Can use the blade of the scissors to cut upto the LIMA in one stroke. Once upto the area where calibre/branches satisfactory, cut the sides of the pedicle from the LIMA. Use a small swab to dry.

Use Castro-forwards to make a bevel shape. First stroke to create an oblique angle, second to flatten/curve the toe, third from the left side to create the other oblique angle.

Make the arteriotomy, and perform the anastomosis as above for a left-sided graft. Use the adventitia to manipulate the LIMA if necessary.

Check for leaks by taking off the bulldog using the left hand while pulling on both ends of the suture with the right. This may be left off if it is the last anastomosis, and Xclamp is being removed imminently.

Tack the pedicle wings at the same level as the anastomosis using ethibond. Check for any leaks on the pedicle, and ligate.

Ensure all bulldogs, swabs, eyelid retractors are taken out. Sucker in the pleura.

Ensure all conduits are anterior and accessible for the top-ends.

Flow down, remove cross-clamp, and place side-bitting clamp with the left hand. Remove the vent and its purse-string. Flow back up.

Remove the aortic adventitia and fat with knife and scissors. Make the appropriate punches and undertake top-ends. If any VF, shock.