In the left thorax, the ports are inserted. A 12 mm camera port is inserted in the fifth intercostal space (ICS) along the anterior axillary line, usually close to the nipple. With the camera inserted from the 12 mm port, two 8 mm instrument ports are placed, one in the third ICS and the other in the seventh ICS, forming a triangular layout. This configuration ensures the optimal maneuverability of robotic instruments. Special attention must be taken regarding the port inserted into the third ICS, as it may interact with the left shoulder and, therefore, can limit its range of movement. For this case, we also inserted in the fourth ICS a laparoscopic 5 mm port for vascular clip applier. The Da Vinci XI robotic system (Intuitive Surgical Inc., California, United States of America) is positioned on the patient's right side. With a 0-degree or 30-degree angulation, the camera provides high-definition, magnified views of the operative field. For most portions of the BIMA harvest, bipolar microtissue forceps are attached to the left robotic arm and spatula cautery to the right arm.

The RIMA is approached first, as a harvested LIMA would likely be damaged with the robotic instruments working on the RIMA bed. The left lung is deflated. Access to the RIMA bed involves creating a substernal plane extending to the right pleura. The right pleura is kept intact as much as possible to avoid right lung protrusion. Dissection begins by identifying the pulsating artery beneath the endothoracic fascia. The parietal pleura and fascia are carefully incised using monopolar cautery, exposing the RIMA along its length. The artery is skeletonized using sweeping movements of robotic instruments. The small branches are cauterized using a monopolar cautery spatula, or for large branches, we use the bipolar cautery micro forceps. The larger branches can also be clipped and divided with robotic scissors only with the Da Vinci Si, as the Xi has no clipping instruments. It is crucial to dissect and transect the proximal mammary vein to allow very proximal RIMA dissection. This can be performed with the help of a retractable spatula introduced under the xyphoid to push on the mediastinal fat close to the innominate vein. Video 1 shows the RIMA harvest.

Video 1
Right internal mammary artery harvested robotically. Link: https://youtu.be/q3Kdos5j2tw

The LIMA is dissected after the RIMA. The right lung may be fully ventilated, and the left may be ventilated at low volumes with CO2 inflation at 12 mmHg. The LIMA dissection mirrors the technique used for RIMA, employing the same robotic instruments and movements. Adjustments in port angulation or positioning may be required to optimize access. Heparin is administered once both mammary arteries are freed, and the distal end of them are clipped and divided. Once the mammary arteries are cut, they systematically have a torsion movement leading to a 360° twist. To avoid this, it is paramount to clip the distal end of the mammary on the mediastinal fat. Video 2 shows the LIMA harvest.

Video 2
Left internal mammary artery harvested robotically. Link: https://youtu.be/ZIaAe90EA6g

Once BIMA are harvested, a 4 - 6 cm long anterolateral thoracotomy is made (Figure 1), which usually englobes the 12 mm portal insertion incision. Before fully opening the ICS, a small hole is made in the ICS, and digital palpation is done to feel the apex of the heart, which indirectly shows us that we are in a good spot regarding surgical exposure. Usually, the fifth ICS is opened, but if necessary, the fourth or sixth ICS may be opened to achieve adequate surgical exposure. After opening the ICS, a mini-thoracotomy retractor is placed. The first step is the mammary recovery. Each mammary is exposed with two 6-0 Prolene® sutures. One on each side of the mammary to avoid any twist. The flow in the mammary is accessed. The pericardium is then opened longitudinally.

Fig. 1
Postoperative incision and port insertion sites.

The next step is the distal anastomoses. Blood pressure should be brought up to allow manipulation of the heart with hemodynamic stability. We aim for a systolic blood pressure of 140 - 150 mmHg. The sequence of distal anastomoses is dictated by the surgeon’s preference and the potential degree of ischemia in each territory. We routinely start with LAD anastomosis.

The Octopus® NUVO (Medtronic, Minnesota, United States of America) adequately exposes and stabilizes the coronary target. Complementarily, pericardium stay sutures may be placed to optimize coronary exposure in special for the lateral and inferior walls. The Octopus® NUVO is applied using the 6 mm incision at the sixth/seventh ICS. The stabilizer holder is fixed on the table arms to obtain maximal stabilization. CPB can be used with femoral cannulation in cases of inadequate exposure of the target vessels or hemodynamic instability. If the patient presents hemodynamic stability with adequate coronary exposure, we proceed to the distal anastomosis off-pump. For coronary bleeding control, a temporary suture is placed around the coronary artery to be grafted, proximally to the planned arteriotomy. This occludes the coronary for a short period and allows better visualization. A blower is also used to improve the visibility of the coronary. After arteriotomy, an intracoronary shunt can be placed, and the suture around the coronary artery may be removed. Then, the distal anastomosis is performed with a 7-0 or 8-0 Prolene® suture with standard instruments. We check all bypass grafts with a Doppler flow probe. Protamine is administered after confirmation of adequate graft flow and hemostasis.

By the end of the procedure, a drain is inserted in the left pleural space via the incision where the 8 mm portal for the left robotic arm was placed. The left lung is reinflated, and the proper lie of the grafts and the chest tube should be checked during lung reexpansion. The ICS is reapproximated, and the subcutaneous tissue and skin are closed. Intercostal nerve infiltration with anesthetic drugs is an option to optimize immediate postoperative pain control.

Carbon dioxide insufflation pressures are maintained between 6 and 12 mmHg throughout the procedure to enhance visibility. Blood pressure and saturation are closely monitored to avoid hemodynamic instability, especially during port placement, RIMA harvest, and pleural insufflation. Conversion to sternotomy is an option in cases of inadequate visualization, bleeding, or hemodynamic compromise. The safety and effectiveness of the procedure must never be jeopardized by the minimally invasive nature of the robotic approach. Adequate training and experience with robotic systems are essential for surgeons performing these procedures to minimize risks and complications.