**7.5 Robotic-assisted coronary anastomosis, device-driven fashion**

Contrary to robotic-assisted MIDCAB surgery, the coronary target anastomosis part of TECAB surgery is also completed endoscopically. There are two techniques for robotic-assisted anastomosis and applications differ depending on preference. If device-driven anastomosis is to be made, a 15 mm working port is required to insert C-Port Flex A system; on the other hand, if the hand-sewn technique is to be used, a 12 mm working port is required to embed the coronary shunts and sutures (Ethicon Surgical, Somerville, NJ, USA).

A 30-degree scope is used for better visualization. To begin with the devicedriven technique, the left and right robotic arms are equipped with Black Diamond forceps. The stabilizer at the 4th port is replaced with a DeBakey forceps and the 15 mm working port is loaded with the Flex A system to perform the automated coronary anastomosis.

The Flex A device is inserted along with its neutral position which points to the diaphragm as the anvil facing heart and cartridge facing sternum and held by the DeBakey forceps. Then it is rotated in a way that now cartridge faces down while the anvil faces the sternum. Later on, the device is moved vertically to a position that faces the camera. In order to inspect and trim encircling tissue, ITA is also oriented and positioned along with the device. The placement of LITA inside the cartridge can now be ready to complete after the 10-mm linear arteriotomy. Following the placement of heels of the arteriotomy to the designated sites on the cartridge by two Black Diamond forceps, tableside assistant lowers the piercer onto the heel clip and fixates the heel of LITA onto the cartridge. During the next step, which is lowering the shield guard, slight bending of the guard can enhance the hood of the anastomosis. Then, both sides of the heel are positioned to the contrary sides of the cartridge to match with staple bays. During this placement, it is of vital importance that each staple bay is correctly matched with LITA tissue and there should be no folds in the LITA after it is properly positioned. In order to achieve this, firstly tableside assistant lowers the right-wing guard. Then, before lowering the left-wing guard, the assistant should also remove the piercer to fixate LITA in the proper place. Lowering both of the wing guards and fixation of LITA to its proper place marks the loading of the conduit so that the device can now be moved back to its neutral position and placed nearby to the target vessel on the pericardium.

The 4th port is loaded with the Endo-Wrist stabilizer once again to stabilize the coronary target. The silastic snare that encircles the coronary target which previously placed before is now tightened and hemodynamic responses and ECG alterations are observed. ST-segment elevations are tolerated since it's not necessarily a proof of ischemia but can be referred to alterations in signal detection because of the physical displacement of the heart unless followed with hemodynamic compromise. Ischemic preconditioning might be beneficial to prepare the myocardium before coronary occlusion [43].

After the coronary flow is blocked by tightening the silastic snare, a small coronary arteriotomy in the core of a previously placed CV-8 Gore-Tex suture (Gore Medical, Flagstaff, Ariz) is performed by an endo-knife (Snap-Fit; Intuitive

*Latest Developments in Medical Robotics Systems*

mentioned before.

procedure is repeated.

**7.4 Coronary target(s) preparation**

incision in MIDCAB surgery.

When executing the mediastinal fat retraction with the Endo-Wrist stabilizer, care must be taken to secure that suited proximal dissection of the RITA is accomplished and adequate conduit length is provided. The 0-degree scope is ideally used to harvest the proximal RITA; the artery should be dissected up till the first intercostal branches are uncovered; then several metal clips should be used to divide the medial right internal thoracic vein. In order to widen the anteroposterior space especially in patients with narrow space between the sternum and the heart and thereby decrease the risk of instrument-induced arrhythmias, the stabilizer is then positioned on the epicardial surface while dissecting the caudal extremity of the RITA. Once the RITA is almost entirely liberated but not distally divided from the encircling tissue, attention is drawn to the LITA, which is harvested likewise as

The conduits are prepared with intraluminal papaverine solution injection after the harvesting of both ITAs from the loose areolar tissue is completed over their total length. A bulldog clamp is placed on the proximal RITA after heparinization. To evaluate sufficient flow through the conduit, the distal end of the RITA was occluded by a metal clip, and partially transected only the proximal site of this clip with the help of robotic Potts scissors afterward. Meanwhile, a syringe of 1:20 diluted papaverine solution connected to a 20-G Perifix® epidural catheter (B. Braun, Melsungen, Germany) is operated by the table-side assistant via the working port and then inserted tenderly by the console surgeon into the lumen of the RITA. Papaverine is injected as the catheter is removed. The table-side assistant should extract arterial blood before infusing the papaverine to confirm the correct intra-luminal catheter location. The catheter should then be slowly retrieved, and immediately after catheter removal, the RITA is distally clipped. For LITA, the same

If robotic-assisted MIDCAB surgery is the selected approach, this step continues with removing the robotic instruments and ports and expanding the camera port incision to a 5-cm left anterior mini-thoracotomy to provide direct access to the selected coronary targets, while TECAB surgery continues with robotic assistance in the rest of the procedure thereby does not need a wider thoracotomy incision. The retractors are used in Robotic-assisted MIDCAB to provide a better view similar to regular MIDCAB surgery. A pericardiotomy is performed through thoracotomy incision, which is applied anteromedially in the direction of the apical part of the heart, imitating the orientation of the LAD thus allowing the ITA to enter the pericardial space without any twist or torsion afterward. After the pericardiotomy, the LAD is exposed and can be stabilized with the help of external vacuum-assisted or pressure-assisted systems. After the coronary target preparation is finished, a direct hand-sewn graft-coronary target anastomosis is applied through the thoracotomy

TECAB surgery, which stands out among all the surgical myocardial revascularization strategies due to its minimally invasive nature, requires two additional ports which should be placed in this stage of the procedure. A 12-mm 4th robotic port for the Endo-wrist™ stabilizer and finally, a 12 mm or 15-mm working port for

With the help of the Endo-Wrist stabilizer, the coronary target(s) is stabilized and then exposed. Proper exposure is served by using low cautery energy with gentle opening of the overlying epicardium, which in our belief is more beneficial than sharp dissection to obtain better hemostasis in an endoscopic

coronary anastomosis instead of a de-novo thoracotomy incision.

**84**

workspace.

Surgical, Sunnyvale, Calif) using a purse-string stitch. This stitch is required to seal the insertion site of the anvil after the device is removed, since it is not part of the anastomosis. The anvil is then inserted and positioned parallelly to the coronary target. Placement of anvil inside the lumen of the vessel is crucial before moving on with the following steps of the anastomotic procedure. Then, tableside assistant activates the device and performs the anastomosis. Following the proper formation of anastomosis, the cartridge is released, the shield guard is raised, and anvil is discharged.

After the suture is tied, one should always look for potential bleeding. If that's the case, the surgeon should add additional stitches.

Occasional examination of the transit-time flow measurement (TTFM) of the graft is necessary [44–46]. In order to do this, a flexible probe through the port like Medistim (Medistim Inc., Oslo, Norway) can be used. This system provides valuable information about the procedure like mean blood flow, pulsatility index, and percentage diastolic filling. In addition, consideration of the competitive flow should also be closely examined.

If sequential grafting is needed, instead of Flex A device which is only applicable for end-to-side anastomosis, a hand-sewn technique comes into play. Thus, sequential grafting should start with the anastomotic device, then should continue with the hand-sewn approach.

#### **7.6 Robotic-assisted, hand-sewn coronary anastomosis**

Because of the aforementioned cases, in order to perform robotic-assisted coronary anastomosis, the anastomotic device is not mandatory since the hand-sewn technique is also capable of doing the same procedure.

Histological studies also prove that device-driven anastomosis can be comparable with the hand-sewn anastomosis [47–49].

It is crucial to prepare the anastomotic sites before insertion of the suture in the thoracic cavity with the endo-wrist stabilizer. In order to perform LAD anastomosis, a 30-degree down scope provides better visualization, whereas a 30-degree up (or 0-degree) scope is preferred for left circumflex branch anastomosis. Also, observing some crucial parameters like ECG alterations, variables derived from TEE, and hemodynamic responses during the 5 to 8 minutes of myocardial ischemic preconditioning is recommended. During this period, required items like shunts and sutures can be inserted into the thoracic cavity. After clamping the ITA with a small bulldog clamp, Pott scissors are used to transcend and trim to the adequate length. It is advantageous to clip the distal side of the ITA to the encircling pericardium to deal with the conduit when conducting the anastomosis. Endo-knife (Snap-Fit; Intuitive Surgical, Sunnyvale, California, U.S.) assisted arteriotomy is performed and extended with Pott scissors after a short reperfusion duration.

Both robotic arms are now equipped with Black Diamond forceps. A correct size shunt is now positioned (via the regular off-pump coronary artery bypass techniques) and the snare is released. A double-arm 7–0 Pronova suture is used to induce anastomosis in a continuous manner (Johnson & Johnson Medical, New Brunswick, New Jersey, United States). Suturing from the farthest side of the surgeon is introduced in the center of the arteriotomy, and should be completed on the adjacent side of the surgeon.

The stitches are normally carried out on the coronary artery in an outside-in fashion, but this procedure can be altered in the opposite direction only if there is the presence of calcified plaques within the coronary target wall. The graft is then parachuted onto the target artery. It is advised to insert a shunt within the conduit

**87**

*Robotic Coronary Artery Bypass Grafting: History, Current Technique, and Future Perspectives*

if there is confusion about the visualization of the heel of the conduit. The suture should be tightened in order to stop bleeding after the suture is finished. The

Finally, the proximal snare and the bulldog clamp are released. After performing every anastomosis, TTFM should be evaluated with a flexible MediStim probe. If the pulsatility index is greater than 5 and the mean arterial blood flow is less than

After the grafting procedures have been finalized with satisfactory results and adequate hemostasis, all the items used in the surgical procedure are cleared away from the thoracic cavity. Extra-pericardial fat that has been transferred to the lateral side is now sutured back to the medial border of the pericardium to cover the anterior face of the heart and the graft, and a 4–0 V-Loc suture (Medtronic, Minneapolis, Minnesota, United States) is used to conduct both of these proce-

A 24-French Blake Drain (Ethicon Inc., Somerville, New Jersey, United States) is placed in the right thoracic cavity through the sub-costal port, and the second 24-French Blake Drain is also placed in the left thoracic cavity through the left port.

If the surgery is performed on an arrested heart with CPB support, a 'hot shot' of cardioplegia or warmblood is administered before deflating the endoballoon. Only after the robot is undocked, all ports are removed, and ventilation is fully restored, will separation from the CPB support, protamine administration, and decannulation be carried out. To minimize the risk of bleeding on the port sides, it is strongly recommended to re-inspect the port sides with the scope after protamine

Finally, all port incisions are sealed with subcuticular stitches and in this way,

At first, the TECAB technique was limited to treating single vessel disease with LITA-LAD anastomosis on an arrested heart with CPB support and in time it is proven to be safe and feasible [50, 51]. Since robotic surgical technology continues its exponential growth, the advancements in the next generations of the da Vinci robotic systems will be expected to enhance treatment options even for the high-

Robotic-assisted, totally endoscopic, off-pump CABG has been shown to be safe and feasible in treating the multivessel disease and offers outstanding results in experienced hands. To achieve successful results, the whole surgical team should master robotic surgery, and be in harmony during the procedure and in the meantime, the highest attention should be directed to the hemodynamic and hemostatic

However, the surgeons should note that robotic-assisted CABG surgery has a steep learning curve and should start with gaining experience in the treatment of single-vessel cases before progressing to multivessel procedures. Intensive training on hand-sewn suturing techniques using dry and wet-lab models is essential and highly recommended. Due to the steep learning curve and the lack of excellence centers focused on the robotic-assisted CABG, the interest from the industry has

shunt(s) should be withdrawn just before the suture is tightened.

15 mL/min, we recommend that the graft be checked.

dures. The left lung is suctioned in and the lung is reinflated.

is administered. For off-pump TECAB, this is extremely unlikely.

The robot is undocked, and all the ports are removed.

*DOI: http://dx.doi.org/10.5772/intechopen.99399*

**7.7 Final surgical maneuvers**

the surgery is now completed.

risk patients with multivessel disease.

parameters of the patient.

been half-hearted.

**8. Conclusion**

#### *Robotic Coronary Artery Bypass Grafting: History, Current Technique, and Future Perspectives DOI: http://dx.doi.org/10.5772/intechopen.99399*

if there is confusion about the visualization of the heel of the conduit. The suture should be tightened in order to stop bleeding after the suture is finished. The shunt(s) should be withdrawn just before the suture is tightened.

Finally, the proximal snare and the bulldog clamp are released. After performing every anastomosis, TTFM should be evaluated with a flexible MediStim probe. If the pulsatility index is greater than 5 and the mean arterial blood flow is less than 15 mL/min, we recommend that the graft be checked.
