Department of Cardiovascular Surgery
University Medical Center
Zaloska 7, 1000 Ljubljana
Slovenia

Surgery: Prof. Borut Gersak, MD, PhD

Incisions

Firstly, a 1,5 cm long skin incision is made by the scalpel, directly over the right femoral artery and vein in such a fashion that outer 1/3 of the artery and vein is not affected. The height of incision is around 1 cm below to the inguinal ligament with direction exactly in the line of femoral groove. Next the subcutaneous tissue is dissected with electrocauter and 1,5 cm sharp retractor is exposing the still covered artery and vein. The small hook, pulling skin lateral is helping to position common femoral artery in the mid part of incision. With scissors just the upper part of femoral artery in length of just 1 cm is exposed to the level of adventitia. It has to be mentioned that not any other dissection is exposing the artery, leaving it surrounded with all adjacent subcutaneous structures. Afterwards the hook is pulling medially, positioning the femoral vein in mid part of skin incision, and the upper part of the vein is exposed in the same manner as with the artery. When this is done, two 5/0 Prolene purse string sutures with tourniquet applied to them are positioned on a femoral vein. First one is using four bites and the second one just three. Then two 5/0 Goretex sutures with Ethicon pledgets and tourniquets are used to prepare the femoral artery for the cannulation (Figure 8).

Secondly, the thoracic skin incision is made. There are differences in men and women. In men the incision in parallel to the nearest intercostal line lying below the nipple, with skin incision in principle laterally to midclavicular line.
In women, the marker is used prior to cleaning to mark the submammary groove, which is distorted when the patient is positioned for surgery. So the skin incision is following this line and is typically done also slightly more laterally to the midclavicular line than in men.

The length of skin incision in thorax is 2,5 - 3 cm done with scalpel and then subcutaneous structures are dissected with electrocauter but not yet exposing intercostal musculature. The intercostal space where the real approach will be is chosen under the following criteria:
1. convenience for the patient: some patients may be obese and in those it may be difficult to expose the 4th intercostal space with this limited incision, leaving more postoperative pain, tissue destruction and damage, so the 5th space is used.
2. shape of the thorax: if the thorax is more wide, the heart is lying more on the diaphragm, so 5th space can be used. If the thorax is narrow, and the heart is positioned more vertically, the 4th intercostal space will be a good choice. The chest X - ray is carefully examined prior to surgery and all the intercostal spaces from 4th - 6th are considered for approach.
3. position of the diaphragm: sometimes the diaphragm is positioned very high, so higher intercostal space than normal may be more convenient to use.

When it is determined which intercostal space will be used the electrocauter is used to dissect the tissues deeper, not enlarging the length of incision, but deepening it and special care is taken that all the bleeding is prevented. At least at this time the lungs on the right side should be deflated. When the pleural space is opened, the length of the intercostal incision is exactly of the same size as the size of the skin incision (Figure 9). Immediately after the pleural space opening the 3 mm skin incision is made, one intercostal space lower and 2 - 3 cm more laterally, the 5mm wide port is introduced, palpating and protecting the diaphragm with left hand middle finger. This port will be used for venting and at the end for drainage, however at this stage 2mm wide tube with CO2 connection is inserted through this port immediately - the CO2 flow is 3 litres/minute. Around 30 cm of the tube is inserted into the thorax, trying to reach the lowest part of it with the opened end part of the tube.

Then, as a rule, in the same intercostal space as the intercostal incision was done another 5mm port is inserted, which will be used as a camera port. In some rare cases this can be done also one intercostal space higher.

Medium size soft tissue retractor is inserted through the intercostal incision and soft tissues are pulled aside to open the working port (Figure 10).

Cannulation

In general, no - touch technique is used for artery and vein. Firstly, the vein cannulation is done after full heparinization. The anaesthesiologist is showing TEE view of right atrium with superior (SVC) and inferior vena cava (IVC). A needle is inserted with the opening looking up into the femoral vein, guiding wire is inserted and shown in the right atrium. Then hard 14Fr dilator is used to dilate the vein, prior to insertion of venous cannula. Insertion of the venous cannula is in five stages: first 10 cm of smallest dilator is inserted, next 5 cm of the middle and then the cannula till the holes are inside the vein. At all the time guiding wire is observed on TEE. As soon as holes are inside, the two dilators are removed for 5 cm and the cannula is pushed into the right atrium. There should be no resistance at any time during advancing cannula. At the 35 cm mark the two dilators are pulled out for about 10 cm and the tip of venous cannula is positioned at the junction of IVC and right atrium (Figure 11).
The both cannulas (from SVC and IVC) are connected and loosely secured, thus enabling reposition during operation if necessary.

Next, arterial cannulation is performed under the same rules as venous. Thoracic aorta is shown on TEE, guiding wire is inserted through the femoral artery and pushed inside till the wire is clearly seen on TEE. The artery is dilated with 14Fr hard dilator and then Port Access endoreturn arterial cannula is inserted 2 - 3 cm into the femoral artery, connected, deaired and tightly secured with 2/0 suture. The perfusionist is giving 100 ml of fluid slowly through this cannula, perfusion pressure is monitored and TEE is checked. During this procedure, the endoaortic balloon (endoclamp) is inserted into the Y connector. When the perfusion test is stopped, the guide wire for the endoclamp is inserted into thoracic aorta, the wire has to be seen on TEE. Then anaesthesiologist is showing aortic valve and ascending aorta on TEE while the guiding wire is advanced almost to its end into the endoclamp. At this stage the wire is rarely seen on TEE in ascending aorta, because of its length, so the endoclamp is inserted into the femoral artery and up into thoracic aorta. As soon as guide wire is seen on TEE in ascending aorta (Figure 12), the assistant is pulling it backwards while the surgeon is pushing the endoclamp into the aorta. Under this circumstance the endoclamp is slowly advanced into ascending aorta. When it is seen on TEE in ascending aorta (Figure 13), the guiding wire is removed completely, and the endoclamp is withdrawn till it almost disappears on TEE (Figure 14). Just a small part of distal tip has to be seen on TEE. The endoclamp is then secured just with the help of screw on Y arm of arterial cannula. It has to be explicitly mentioned again that firstly the guiding wire and than later on endoclamp have to be seen on TEE in ascending aorta. If the guide wire is not seen in ascending aorta while its' whole length is in the patient and also the endoaortic ballon is reasonably advanced into thoracic aorta, every measure has to be taken to see and position it in ascending aorta to prevent positioning in any of great aortic arch arteries.

Operation

The 5 mm camera is inserted through the camera port. The pleural cavity should now be with completely deflated right lungs, so the @ 2 mm needle with sheet is inserted 2 cm dorsal to camera port, needle withdrawn and CO2 tube inserted through this port.

If diaphragm is high, making exposure difficult or making operating angle to steep, 2/0 figure of eight suture is placed on muscular part, a needle as much as close to the diaphragmatic level is inserted dorsal to vent port, suture snare applied pulling diaphragmatic suture outside of thoracic cavity, tourniquet applied and diaphragm pulled caudaly.

Pericardial fat is removed with electrocauter if necessary in those areas, where the pericardial opening will be. Special attention is payed in the area near the phrenic nerve, cranially and caudaly to it.

Then the cardiopulmonary bypass is started, and slowly, if necessary, vacuum assisted drainage is used. The pericardium is opened for 1 cm, two 2/0 stay sutures on both sides are pulled up and the rest is opened in inverted T fashion. Caudal part of cut is ending directly above the IVC, cranial part is ending at the pericardial eversion near SVC. Two 2/0 stay sutures in U fashion are applied horizontally along the phrenic nerve (Figure 15) , above or if suitable, below it. A needle is inserted between camera port and CO2 port, suture snare used to pull both "phrenic nerve stay sutures" outside the thorax, tourniquet applied for securing both sutures.

Soft dissection with tip of cell saver aspirator is used to determine the position of IVC in relation to the right and left atrium. If possible, tip is inserted below IVC, reaching diaphragm, so the left atrial opening later on will not interfere with the right atrium.
Sharp dissection with scissors is used to separate left and right atrium horizontally in interatrial groove (Figure 16).

Endoaortic crossclamping

Distal part of the tip of the endoclamp is determined on TEE. The perfusionist is venting for a few seconds the aortic root line. Assistant surgeon is slowly inflating the balloon, while the surgeon is pulling the endoclamp out of the ascending aorta. As soon as 1/3 to ½ of the determined ( related to aortic diameter) balloon volume is given, the scrub nurse is as fast as possible injecting adenosine (0,25 mg/kg) via a side port of endoclamp catheter. At this time heart is stopped immediately and the surgeon is pulling some additional millimetres of the endoclamp from the aortic valve into the place above sinotubular junction (Figure 17). This will also take the slack out of the catheter. As soon as adenosine is stopped, the perfusionist is starting to give the cardioplegia. The pressures (right and left radial, aortic root, cardioplegia pressures and pressure in the balloon) are carefully observed; if necessary some small adjustments in the endoclamp position are done. Then the catheter is locked and the insertion depth of the catheter is noted. When the team agrees that the situation is stable, and the heart is adequately stopped, the 0,7 - 1 cm small incision in the left atrium is made close to the interatrial groove. Immediately the cardiotomy aspirator is decompressing the heart.

Straight Port Access scissors are used to open the remain of the left atrium, in most cases approximately 3,5 - 4 cm. Care is taken not to open the left atrium too much but exactly in accordance to the wideness of left atrium retractor which the surgeon will use.

If the left atrium is small, wider and shorter left atrial retractor is used (3,5 cm width).
In enlarged left atria TEE evaluation prior to cardiac arrest is used to determine the position of the enlargement (the atrium could be enlarged in many different directions). According to this longer or shorter left atrial retractors are used in combination with their wideness.

During decision making left atrial vent is pushed through the 5 mm vent port into the left superior or inferior pulmonary vein. Vent is having smooth tip, air lock screw and is preformed in L shape. Since this is still the time, when cardioplegia is given it is important to use left vent and cardiotomy aspirator in combination.

The left atrial retractor is put through the thorax into the left atrium and camera is pushed into position to show the mitral valve. The left atrial retractor is temporarily positioned in such a way, that it is not interfering with lateral (in this case left side as seen on screen) part of the atrium - this is the area where the inflated endoaortic balloon is - the interference may cause balloon migration due to applied force, challenging and complicating operation resulting in poor exposure of the anterolateral mitral commisural region.

At this stage the position for left atrial rectactor holder arm is determined, and through 3 mm hole the retractor arm is inserted into the thorax. It has to be present in mind that this insertion may interfere with internal mammary artery, still not adequately exposed pericardium or sometimes even with soft tissue retractor. Having this in mind the surgeon is advised to prepare the necessary and optimal conditions during the whole course of operation from the very start.

Then left atrial retractor is positioned. The depth has not to be great, the mitral annulus below the retractor arm has to be seen clearly at this stage (Figure 18). Also the retractor arm should be slightly rotated counter clockwise for about 10 - 20 degrees and pulled directly up till such an extent that anterior leaflet is falling down completely unobstructed (Figure 19).

Then the mitral valve is repaired or replaced.
When 2/3 of the sutures are tied down, the perfusionist is starting to heat the patient. When the sutures are cut, the atrial retractor is moved vertically down till the left atrial suture line is slightly approximated (Figure 20). Firstly, figure of eight suture is put in the upper (near SVC) corner and then the left atrial retractor is removed. After few stitches the lower corner (near IVC) is approached and sutured till the both sutures meet. Then the anaesthesiologist is inflating left part of the lungs and perfusionist is filling the heart, while the surgeon is maintaining the left atrial suture line open for "deairing". The suture is tightened down, heart emptied again and left lungs deflated. The left atrial suture line is checked while heart empty and then again with full (but still arrested) heart. If necessary, now is the time for additional sutures. CO2 bathing is stopped.

Temporary pacemaker wire is placed in the musculature of the right ventricle, and if there is no place (fat) on the left ventricle.

At this stage the perfusionist is filling the heart, the anaesthesiologist is ventilating the left lungs and when on TEE the left atrium is visualised the endoartic balloon is emptied for about 2/3 of the filling volume (1/3 still remaining) and aortic vent is opened to remove remaining air if still there.

The left atrial suture line is checked while the heart beating and if everything is acceptable, the suturing of the pericardium is done with 3/0 Prolene, leaving about 1 cm2 open for drainage.

The thorax is aspirated for blood and when both lungs are filled with air, perfusionist is lowering the perfusion and finally stopping it.

Protamine is given and during this stage firstly femoral venous cannulation is discontinued in retrograde manner, meaning inserting the nonperforated dilator into the cannula, preventing the loss of blood from the holes.
During this, the ports are removed, thoracic drain is inserted through the vent port, soft tissue retractor is removed and all the port holes are sutured.
After withdrawing the balloon catheter from Y arm, femoral decannulation is also retrograde; inserting the nonperforated dilator into the femoral cannula removing it while simultaneously the Goretex sutures are tightened down.

Normally, no additional hemostatic sutures are needed on both cannulation sites.

When thoracic musculature is sutured (no ribs sutures are used because the opening is so small - and preventing postoperative pain from rib involvement) the epidural catheter is inserted from left side of the patient, through the retractor arm opening, between the internal and external respiratory muscles.

The catheter is secured and connected with patient's control analgesic pump (PCA) used to deliver local anaesthetic at the end of the operation and next three days.
The remaining wounds are sutured intradermaly with 5/0 Vicryl.

The SVC is decannulated, the puncture site pressed down for a few minutes with the patient in antitrendelenburg position. The thoracic drain is connected with negative pressure suction line, the patient extubated on table and transferred in ICU.