Anterior mediastinal masses may be approached from the right or the left side of the chest. In our example, a right-sided approach was used. The patient is placed in supine position with a jellyroll or rolled sheet along the posterior mid-clavicular line to elevate the operative side. The arms are tucked with the arm on the operative side allowed to sit slightly below the OR table to allow more space for the robotic arms.

Port sites were determined by preoperative imaging studies (Fig. 28.1). The port sites are positioned along the mid-anterior axillary line for the robotic port 1 and camera port. Robotic port 2 was positioned in the anterior axillary line as shown in Fig. 28.2. In the example case, port 1 was placed in the third intercostal space, camera port in the fifth intercostal space, and port 2 in the seventh intercostal space. When the anterior mediastinal mass sits high in the chest, port placement in the second, fourth, and sixth intercostal spaces may be advantageous. The rib spaces and port sites are marked, then the patient is prepped and draped in usual fashion (Fig. 28.3).

After making a 5 mm incision at the camera port, the chest is entered using the 5 mm Optiview trocar and the 5 mm laparoscope. Stabilize the trocar with your non-dominant hand, while passing the scope and trocar into the chest seeing the layers of the chest wall until lung is visualized (Fig. 28.4). The pleural space is insufflated with carbon dioxide set at 10 mmHg pressure and inspected for adhesions and evaluated for malignant involvement. Decision can be made at this time to convert to an open procedure or continue with placement of the robotic ports 1 and 2. Using the 5 mm laparoscope for visualization, the 8 mm robotic cannulas are placed into port sites 1 and 2. The thick black line on the 8 mm port is positioned just within the intercostal muscle. The 5 mm port is removed and the incision is then extended to fit a 12 mm Optiview port with depth just past the chest wall confirmed with the 5 mm laparoscope in one of the 8 mm port sites. The robot is then driven into the operative field from the contralateral side and perpendicular to the patient centered on the camera trocar as depicted in Fig. 28.5. The ports are then secured into the robotic arms. The 0-degree da Vinci camera is passed into the center camera port. The Cadiere forceps are placed into port site 1 followed by the Maryland bipolar forceps (or robotic vessel sealer) into port site 2 under robotic camera visualization. Bipolar is set at 70 W.

The phrenic nerve is first identified along the pericardium, as this nerve must be preserved and defines the posterior border of the dissection. We use the Maryland bipolar forceps to initiate the dissection of the mediastinal pleura just anterior to the phrenic nerve running along the superior vena cava (Fig. 28.6). The Kittner roll gauzes are inserted into the thoracic cavity through the access port to assist with absorbing minor bleeding and assist with retraction. The dissection of the mediastinal pleura is extended caudad to the inferior pole of the thymic tissue above the diaphragm denoting the right-sided inferior border of dissection. The mediastinal pleural incision is then extended cephalad to the innominate vein (Fig. 28.7). Care must be taken as the dissection nears the innominate vein, as clips may be necessary to divide vein branches to the thymus . Thymic tissue underneath the innominate is dissected free. The thymic tissues are dissected off the pericardium posteriorly to the mediastinal pleura on the left side which is incised at the same level as on the right side. Occasionally, the phrenic nerve may not be visible on the left side. If there is concern, a 5 mm thoracoscope can be placed into the left pleural space to visualize the left phrenic nerve. The anterior dissection is started just medial to the internal mammary vessels (Fig. 28.8). Arterial branches may need to be clipped and divided supplying the thymus. The right-sided superior pole of the thymus is then dissected free using caudad and posterior traction (Fig. 28.9). A clip is usually necessary at the superior aspect of the pole to control bleeding. The dissection is then carried over to the left superior pole, which is similarly dissected away from the inferior neck (Fig. 28.10). The dissection is then carried over to the mediastinal pleura on the anterior aspect of the dissection along the sternum. The left pleural space is entered anteriorly taking care not to injure the left internal mammary artery. The thymus is retracted over to the right side and the left lobe of the thymus is dissected free (Fig. 28.11). The robotic instruments are retracted and robot disengaged from the ports. The 5 mm laparoscope is placed into port site 1 and the Endo Catch bag is then used in the 12 mm camera port. A blunt grasper is used to place the specimen into the bag and removed from the pleural cavity. The incision may need to be widened to accommodate the removal of the specimen. The port sites are then closed with 2-0 vicryl suture followed by 4-0 monocryl subcuticular skin closure. The anterior mediastinal mass was found to be a thymoma , Masaoka stage I on pathology.

Middle mediastinal masses include most commonly lymph nodes and congenital bronchogenic cysts and pericardial cysts . Lymph nodes in the middle mediastinum are addressed mainly with mediastinoscopy, which is a minimally invasive technique to sample paratracheal and subcarinal lymph nodes of interest. Bronchogenic cysts, most common, and pericardial cysts, second most common, are rare congenital entities found in the middle mediastinum [5]. Bronchogenic cysts and pericardial cysts have been addressed with robotic assistance in several case reports [6–8].