◆ A right anterolateral thoracotomy incision may be used for mitral and tricuspid valve repair or replacement, aortic valve replacement, atrial septum defect repairs, and right-sided pulmonary vein isolation procedures for atrial fibrillation. The right anterior thoracotomy may be further divided into a supramammary, usually through the second intercostal space, and a submammary, usually through the fourth or fifth intercostal space.
◆ The right-sided supramammary anterior thoracotomy allows good access to the aortic valve. In most cases, the second or third rib needs to be detached from the sternum, and the right internal thoracic artery would need to be sacrificed. Using a thoracoscope and aortic clamp, with a Chitwood clamp through another site, can provide better exposure of the operative field. In such cases, the detachment of the rib and sacrifice of the internal thoracic artery may not be necessary. This approach is reported to be useful in all aortic valve cases,4 especially in patients with an elongated aorta, in which the ascending aorta is shifted to the right; this would exacerbate an approach through a partial sternotomy.
◆ A right submammary thoracotomy allows an approach to the lower part of the heart, including the mitral and tricuspid valves. A right submammary anterolateral thoracotomy can be an alternative approach for mitral valve procedures; it may be the desirable approach in the setting of a high-risk sternal reentry. A small right thoracotomy can be used for other procedures on the tricuspid valve, for closure of an atrial septal defect, or for tumor resection using a minimally invasive technique. Technologic advancements and new developments in instruments, video-assisted vision, and additional femoral access for the CPB have facilitated minimal incisions, with preserved quality of the surgical repair, similar to that achieved by a traditional sternotomy.5 Minimization of the incision is cosmetically attractive and prevents wound complications of the sternum in high-risk patients. On the other hand, complications such as lung hernia and lymph fistula, as may be found particularly with this method, have been reported.
◆A left-sided submammary anterolateral thoracotomy through the fourth or fifth intercostal space can be used for coronary artery bypass surgery or pericardial window. A lower incision and approach through the fifth intercostal space enables excellent access to the apex of the heart and can be used for transapical aortic valve implantation. It can also be used for implantation of the inflow part of a left ventricular assist device within the pericardial space. A small left anterior thoracotomy incision can be used for single-vessel coronary artery bypass to the anterior coronary circulation, as well as for multivessel coronary revascularization in select cases (see Chapter 5). Compared with off-pump coronary artery bypass grafting (CABG), CABG through a small left thoracotomy has resulted in less wound infection, less transfusion, and earlier recovery.6
◆ A posterior left-sided lateral thoracotomy is used for descending aortic procedures, and this incision can be extended, dividing the rib cage to get exposure of the supra- and infradiaphragm part of the aorta. It provides good access to the left heart bypass. Occasionally, this approach may be used for grafting to isolated lesions of the circumflex coronary artery territory from the descending aorta in situations in which sternal entry carries high risk.
Figure 1.4 Supramammary anterolateral thoracotomy. Excellent exposure of the aortic valve could be obtained with reduced incidence of wound healing disturbance.
Figure 1.5 Submammary anterolateral thoracotomy. The most common approach for minimal invasive mitral and tricuspid valve surgyer. An assistance with video thoracoscope facilitates the procedure and enables minimization of the skin incision.
◆ The patient is placed supine on the operating table and the ipsilateral side is elevated 30 to 45 degrees with the arm placed at the side. An incision is made above the upper edge of the third rib, and the pectoralis major and minor muscles are divided using electrocautery (Fig. 1.4). The desired intercostal space (mostly second, occasionally third) is entered after dividing the intercostal muscles on top of the rib and the rib is disattached from the sternum using an oscillating saw and then pushed into the thoracic space to facilitate exposure. The right internal thoracic artery should be detected and sacrificed with metal clips at this step. With assistance of a video scope and an extra site for the aortic clamp, the supramammary incision could be shifted lateral and the procedure could be performed through the intercostal space without resection and dislocation of the rib.
◆ The patient is placed supine on the operating table, and the ipsilateral side is elevated 30 to 45 degrees, with the patient’s arm placed at the side. A submammary incision is made, and the pectoralis major muscle is divided using electrocautery (Fig. 1.5). The serratus anterior muscle is divided using electrocautery. The dorsal latissimus muscle could be divided or retracted and preserved as well. The desired intercostal space (fourth or fifth) is entered after dividing the intercostal muscles on top of the rib to avoid injury of the intercostal neurovascular bundle. A partial rib resection may be performed to facilitate exposure.
◆ The patient is placed in the lateral decubitus position, with a roll placed underneath the dependent axilla. After the patient is secured to the operating table and adequate cushioning is provided to dependent areas, the upper arm is extended anteriorly and cephalad.
◆ A curvilinear incision is started in the submammary region and extended posterolaterally, traversing 1 to 2 cm below the tip of the scapula and extending craniad midway between the spine and scapula (Fig. 1.6).
◆ The subcutaneous tissue and trapezius muscles are divided using electrocautery. The serratus anterior muscle is divided but may be preserved and retracted. The latissimus dorsi muscle is similarly retracted away from the surgical field. The incision may be continued posteriorly up to the level of the paraspinous muscle.
◆ The thoracic cavity may be entered through the fourth or fifth interspace at the top of the rib to avoid the intercostal neurovascular bundle. A partial rib resection may be performed to facilitate exposure.
◆ Chest drains are placed two rib spaces below the entry site. It is helpful to grab the muscle with a clamp and hold it under retraction by insertion to keep enough muscle in the proper position for closure. Pericostal sutures are placed around the ribs, avoiding the under edge of the ribs and intercostal neurovascular bundle. Loosening of this suture could lead to a lung hernia or invagination of the lung if it is not tied properly.
◆ The divided muscle layers are reapproximated using Vicryl sutures. It is important to identify the firm fascia of the muscle to secure the reapproximation. The skin is closed with subcuticular sutures or skin staples.
Figure 1.6 Posteolateral thoracotomy and the possible extension of the skin incision for extended aortic surgery. The patient is positioned in lateral decubitus position. The groin is slightly rotated to maintain access to the femoral vessels.
Keywords : Cardiac Surgical Techniques, Surgical Incisions, Basic Techniques, sternotomy, partial sternotomy, lateral anterolateral thoracotomy, posterolateral thoracotomy, Thoracotomy, Approaches in Thoracotomy, Thoracotomy Closure, Further Considerations