Chapter 10 Operative Exposure in Thoracic Trauma: Incisions

This chapter will discuss common thoracic exposures, including median sternotomy, left anterolateral (or resuscitative) thoracotomy, and the “clamshell” incision. The use of these incisions for exposures of specific injuries will be discussed in subsequent chapters.

Learning Objectives

By the end of the ASSET course, participants should be able to do the following:

1. Describe indications for median sternotomy and demonstrate the surgical technique.
2. Demonstrate use of the Lebsche knife.
3. Describe indications for resuscitative thoracotomy and demonstrate the technique.
4. Demonstrate the technique to open the pericardium while preserving the phrenic nerve.
5. Demonstrate the surgical technique to expose and clamp the descending thoracic aorta.
6. Describe indications for clamshell thoracotomy.
7. Demonstrate the surgical technique of extending a resuscitative thoracotomy into a clamshell thoracotomy.

Median Sternotomy

Considerations

• The patient must be stable enough to make it to the operating room; otherwise, resuscitative thoracotomy should be performed (refer to the following section).
• This incision is generally reserved for access to the anterior mediastinum or great vessels.
• However, it provides limited exposure of the left subclavian.
• This is the ideal incision for parasternal cardiac stab wounds with cardiac tamponade (i.e., within the cardiac box).
• Cervical extension provides excellent exposure of both carotid arteries.
• If cardiac tamponade is confirmed or suspected, large-volume resuscitation should be avoided, as this will increase preload and make the tamponade worse.

Technique

• Prep the patient from chin to mid-thigh. Make a vertical midline skin incision, centered over the sternum, from 1 cm superior to the manubrium to the tip of the xiphoid process (Figure 1). Continue down through the decussation of pectoralis fascia onto the sternum with electrocautery.
• The interclavicular ligament is incised, and the soft tissues lying superior and deep to the manubrium are digitally cleared from their attachments to the bone. This procedure moves the innominate vein and surrounding tissue posteriorly so that they are not inadvertently divided with the saw (Figure 2).
• The fat and nearby peritoneum are bluntly detached from the xiphoid process, which is either excised or divided at the midline. The index fingers of each hand are then inserted below the sternum, at the manubrium and the xiphoid, allowing soft tissues to be bluntly dissected free from the underside of the sternum (Figure 3).

• The sternum is divided taking great care to stay in the midline, as failure to do so can make closure difficult. It is useful to mark the midline with electrocautery to help guide the division.
• The sternum is most commonly (and easily) divided using a powered sternal saw (Figure 4). When using a sternal saw, care must be taken to avoid injury to the underlying heart and great vessels by lifting the saw while “toeing” the right angle piece at the end of the saw blade upward.
• The sternotomy is most easily done with a power saw. If this is not available, the sternum can be opened with a Lebsche knife (Figures 9 and 10).
• When using the Lebsche knife to divide the sternum, it is best to start at the xiphoid process and advance to the manubrium (Figure 10). The reason for this is that the hammer must be swung hard to efficiently divide the sternum, and when starting at the top of the sternum, the patient’s head and chin will be in the way of this motion.

• Great care should be taken to stay on the midline of the sternum when using the Lebsche knife, as closure of the sternum is greatly complicated if the sternum is not opened along the midline.
• Other tools to cut through the sternum include a bone cutter, a Gigli saw, and trauma shears.
• Once the sternum has been divided, a chest spreader (Finochietto retractor) is placed in the chest, positioning the handle such that the incision can be extended either into the neck or the abdomen if needed (Figure 5).
• As the chest spreader is opened, adventitial tissue will need to be bluntly dissected from the underside of the sternum to expose the thymic tissue and the pericardium (Figure 6).
• In the setting of pericardial tamponade, the pericardium should be opened initially with a scalpel (scissors will generally not work), taking care not to further injure the underlying heart (Figure 7). The remainder of the pericardium is then opened with scissors (Figure 8).
• The pericardium should be opened all the way to the top, with a finger inside the pericardium as a guide. The pericardiotomy incision should be carried inferiorly to the base of the heart and then extended horizontally for a short distance on either side to make an “inverse T” incision, taking care to avoid the phrenic nerve.
• Repair of cardiac injuries is discussed in chapter 11.
• Exposure of the heart and mediastinum is facilitated by placing interrupted sutures from the edge of the pericardium to the skin. This will raise the heart anteriorly in the chest, facilitating evaluation and repair.

Resuscitative (Left Anterolateral) Thoracotomy

Resuscitative thoracotomy (RT) provides exposure of the heart, distal descending thoracic aorta, left lung, and distal esophagus. It allows for rapid opening of the pericardium, open cardiac massage, repair of many cardiac injuries, cross-clamping of the descending thoracic aorta, and control of the left lung hilum.

Considerations

• It is important to have the required equipment in place and be sure that members of the trauma team know their individual responsibilities.
• RT is performed rapidly in the setting of controlled chaos, and it is important that all team members are protected from bodily fluids and inadvertent injury from sharp instruments or the sharp ends of broken ribs.
• Keeping the number of individuals around the bed to the minimum required to perform the procedure will limit the potential of injury or contact with bodily fluids.
• In the setting of penetrating trauma, it is important to rapidly expose all of the patient to include evaluation of the back. This step can help identify other wounds, which would allow prediction of trajectory and may also reveal additional fatal injuries (e.g., transcerebral gunshot wound) that may preclude performance of RT.
• Simultaneous control of the airway, IV access, balanced blood product resuscitation, and placement of a right chest tube should be undertaken by other available team members.

Technique

• The left arm should be positioned above the patient’s head.
• RT is performed using an incision in the fourth interspace, just superior to the fifth rib. The area just below the nipple (in males) and in the inframammary crease (in females) will correlate with the appropriate interspace in most individuals.
• The incision should extend from the edge of the sternum to the posterior axillary line, following the curve of the rib posteriorly and aiming for the tip of the scapula (Figure 11).
• The incision should be made with a scalpel and not electrocautery, as time is of the essence. If possible, the incision should be made just below the inferior border of the pectoralis major, as cutting sharply through this muscle will cause unnecessary bleeding and disability.
• A useful technique is to cut down rapidly on top of the center of the fifth rib and follow the rib medially and laterally, exposing the anterior surface (Figure 12). The intercostal space is then entered sharply above the rib to avoid injury to the neurovascular bundle, and scissors are then used to divide the intercostal muscles.
• Care should be taken to avoid injury to the intercostal neurovascular bundle, which courses immediately inferior to the rib. Although the latissimus muscle does not have to be transected, the intercostal muscle incision should be extended as posterior as possible. This step will help spread the ribs. The rib spreader is inserted with the handle toward the bed so that it won’t be in the way if the incision needs to be quickly extended to a clamshell (Figure 13).
• Once in the chest, check the pericardium first. If pericardial tamponade is the reason for cardiovascular collapse, prompt opening of the pericardium provides the best chance for survival. The pericardium should be opened with a scalpel, staying anterior to the phrenic nerve (Figure 14) and taking caution not to lacerate the underlying heart.
• After opening the pericardium with a scalpel (Figure 15), scissors are used to open it longitudinally (Figure 16) from the aortic root to the apex of the heart, taking care to preserve and stay anterior to the left phrenic nerve (Figure 14).
• The pericardium should be fully opened such that the heart can be delivered out of the pericardial sac for manual massage, as well as to prevent herniation of the heart through a small pericardotomy.
• Cardiac massage is performed by squeezing the heart between the palms of both hands or, alternatively, using one palm behind the heart to compress it against the sternum.
• After opening the pericardium, the next step is to clamp the descending thoracic aorta.

• Clamping the descending aorta is usually not as easy as it sounds. The lung must be retracted anteriorly to expose the descending aorta. This may require mobilization of the lung by taking down the inferior pulmonary ligament (see chapter 15).
• The descending aorta is covered by a thick parietal pleura, which must be opened in order to place a clamp. The descending aorta sits just anterior to the thoracic spine, and the parietal pleura can be opened safely by placing scissors against the spine just posterior and parallel to the aorta. Using the scissor tips to “spread, cut, spread” at this level allows for a window to be opened between the spine and the underside of the aorta (Figure 17).
• This process is repeated anterior to the aorta between the aorta and the esophagus. Identification of the esophagus is facilitated by placement of a nasogastric tube, if time and resources allow.
• The anterior and posterior windows in the parietal pleural are further bluntly developed so that a noncrushing aortic clamp (DeBakey) can be placed across the aorta from left to right (Figure 18).
• The aorta should not be completely encircled with dissection, as this risks injury to the spinal arteries.

Clamshell Bilateral Thoracotomy

• This incision is indicated for cases in which you need to access both sides of the chest (e.g., massive right hemothorax, insufficient exposure) to delineate and control injury after RT.
• The clamshell incision is an extension of the RT across the sternum into the right chest, performing a mirror image thoracotomy on the right side.
• The sternum is transected with a Lebsche knife; if that is not available, a rib cutter, heavy scissors, or a Gigli saw can be used (Figure 19).
• If available, a second rib spreader is placed in the right chest, and attachments to the underside of the sternum are dissected free (Figure 20).
• If a second retractor is not available, the rib spreader from the RT incision can be moved over to the sternum to fully open the chest (Figure 21).
• The clamshell thoracotomy provides an unparalleled view of the mediastinum and the great vessels, as well as the lungs on both sides. There are few injuries that cannot be exposed with this approach, as seen in Figures 22 and 23.
• If the patient regains cardiac output, the internal mammary arteries must be identified and clamped, or they will be a source of blood loss.