Chapter 13 Operative Exposure in Thoracic Trauma: Exposure of Pulmonary and Hilar Injuries

This chapter will discuss the exposure of actual or suspected injuries of the lungs and pulmonary hilum. Additionally, the techniques of pulmonary tractotomy, nonanatomic pulmonary resection, hilar control, and lobectomy will be presented.

Learning Objectives

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

1. Describe patient positioning and incision options.
2. Demonstrate how to divide the left and right inferior pulmonary ligaments and the proper exposure for pulmonary injuries.
3. Demonstrate a lung tractotomy.
4. Describe the techniques of nonanatomical lung resection, formal lobectomy, and pneumonectomy.
5. Describe and demonstrate the steps to obtain pulmonary hilar control.

Considerations

• Most primary lung injuries (approximately 85 percent) do not require operative intervention and can be managed with tube thoracostomy alone.
• The primary indications for thoracotomy for lung injury include the following:
• Massive bleeding from the lung, especially in the setting of hypotension
• Ongoing blood loss (classically, > 200 cc/hr for at least four hours)
• Large acute retained hemothorax
• Tracheobronchial injury that interferes with ventilation or oxygenation
• Pulmonary injuries are frequently found in conjunction with other thoracic injuries that require thoracotomy.
• The lung is made up of distinct bronchopulmonary segments, each containing a bronchus, artery, and vein.
• A working knowledge of the hilar anatomy and the orientation of the bronchi, pulmonary arteries, and veins is essential (Figure 1).
• Pulmonary veins are thin-walled and are easily damaged if care is not taken during dissection.

Positioning and Equipment

• The choice of thoracic incision is critical. The goal is to maximize exposure of the injured areas of the chest while also allowing ongoing resuscitation and access to the rest of the patient.
• Unstable trauma patients should be placed supine with the arms out, allowing access to the groin, abdomen, chest, and neck.
• If stable, the patient can be rolled slightly (roughly 20°) anteriorly using bumps, gels, or sandbags to allow greater exposure to the lateral chest and thoracic contents.
• While the formal posterolateral thoracotomy position provides good exposure for lung injuries, it should not be used unless (1) the patient is hemodynamically stable; (2) there are no other injuries to the abdomen, neck, or spine that may need urgent attention; and (3) the downward lung can be protected from blood by a double lumen tube or bronchial blocker.
• If a sternotomy has been done for associated cardiac injury, the right or left hemithorax can be accessed by opening the mediastinal pleura. This will provide access to the anterior portions of the lung but is inadequate for exposure of the posterior aspects. Extension with a thoracotomy incision may then be required.
• Appropriate instrumentation and equipment should be available and ready in the room at the beginning of the case and should include the following:
• A chest or sternal retractor (Finochietto)
• A powered sternal saw for median sternotomy
• A Gigli saw, Lebsche knife and mallet, and rib instruments
• Large clamps, such as DeBakey or Satinsky, as well as Duval lung clamps
• Multiple types of stapling devices with an assortment of staple sizes and types
• Warm lavage fluid (sterile water may improve lysis of red cells) to help remove clots and determine areas of bleeding

Exposure for Control of Lung Injuries

• The choice of incision is dictated by the stability of the patient and the suspected injuries but should be large enough to adequately visualize and control the injuries.
• In most trauma patients, the initial incision will be an resuscitative (anterolateral) thoracotomy on the side of suspected injury, with extension across the sternum (“clamshell” thoracotomy; see chapter 10) as needed.
• A chest tube should be placed on the opposite side if there has not been time to rule out concomitant injury.
• Residual blood and clots should be rapidly scooped from the chest, irrigating with warm fluid if necessary to identify sources of bleeding.
• The inferior pulmonary ligament may need to be taken down to address specific injuries.
• The use of Duval lung clamps may facilitate inspection of the lung while preserving the orientation of the lobes.
• The external opening of lung injuries that extend deep into the parenchyma with active hemorrhage should not be clamped, stapled, or oversewn, as they will continue to bleed internally. Such wounds are best treated with either tractotomy or wedge resection.
• Injuries close to the hilum may require nonanatomic resection or lobectomy.

Mobilization of the Inferior Pulmonary Ligament

The pulmonary ligament is not a true ligament but an extension of the parietal pleura; it surrounds the hilar structures at the lower edge of each lung and fixes them to the mediastinum (Figures 1–5). To expose the pulmonary ligament, retract the lung superiorly and laterally. Next, use scissors to make a small cut in the inferior pulmonary ligament at the inferior edge. Then, bluntly separate the ligament from the mediastinum to the level of the inferior pulmonary vein (Figures 4 and 5).

Pulmonary Tractotomy

• Wounds in the peripheral half of the lung (as measured from the hilum) are usually amenable to a lung-sparing pulmonary tractotomy.
• Pulmonary tractotomy is useful in through- and-through wounds of the lung, as it allows for simultaneous exposure and control (of hemorrhage and air leak) of deep wounds.
• A linear stapler is placed through the wound in the lung parenchyma and fired (Figure 6).
• This maneuver will open the overlying lung and allow exposure of the wound, which can then be sutured (or further stapled) to control bleeding or air leaks.
• If a stapler is not available, the same technique may be accomplished using two clamps, manually dividing the intervening parenchyma, and placing a running horizontal mattress suture beneath the clamp, followed by oversewing.
• Alternatively, if the through-and-through wound is relatively small, the stapler can be placed such that the tip of the device is beyond the wound, and the wound is contained within the jaws of the stapler (Figure 7). This maneuver may completely seal off the raw edges of the wound or decrease the raw surface area that will require subsequent suturing (Figure 8).

Nonanatomic Resection

• The lung is extremely forgiving of nonanatomic resections due to its dual blood supply. Isolated areas near the periphery of the lung can be wedge resected with a linear stapling device, providing vascular and air leak control (Figures 9 and 10).
• Lung clamps are used to grasp the lung and manipulate it into a configuration that allows for optimal application of the stapler.
• A complete nonanatomic resection may require several sequential stepwise firings of the stapler.
• Manual compression of the lung and/or closure of the stapler for 15 seconds prior to firing may compress some of the edema fluid and allow for a more secure closure. Using staplers with
• a higher staple height may be needed in some cases.
• Upon removing the stapler, air leaks or bleeding at the staple line may be oversewn.
• If a nonanatomic resection is performed in the upper lobe, release of the inferior pulmonary ligament permits the lung to fully fill the pleural cavity.

Hilar Control

• Active hemorrhage from the central portion of the lung often requires hilar control before
• complete identification and management of the injuries are possible.
• The lung is a pedicled organ, and proximal control of the pulmonary vessels can be obtained with occlusion at the hilum.
• Effective control of the pulmonary hilum may require division of the inferior pulmonary ligament, as outlined above.
• Once the hilum is identified and isolated, several techniques can be used to gain control:
• The hilum can be grasped with the whole hand, providing temporary manual control. This may also facilitate identification of the source of bleeding.

• • A large-angled vascular clamp can be placed across the entire hilum (Figure 11). While clamping may achieve vascular control, complete occlusion may result in injury to the bronchus (Figure 11).
  • The hilum can be looped with an umbilical tape and snared with a tourniquet (Rumel) for hilar control. This compresses the vasculature against the bronchus. As umbilical tape is quite narrow, a second tourniquet often is needed to obtain full control.
  • The hilar twist is a technique that may be useful primarily during a resuscitative thoracotomy when vascular clamps are not available. Once the inferior pulmonary ligament is divided, the lung can be gently rotated 180°, effectively twisting the vascular structures around the more rigid bronchus (Figure 12). Twisting the lung makes delineation of lung injuries more difficult.
• The downside of all of these hilar control techniques is that they will significantly increase pulmonary artery pressures and can induce right heart failure and cardiac arrest.

Lobectomy and Pneumonectomy

• Most pulmonary injuries can be addressed by nonanatomic stapled lobectomy.
• Injuries in the central portion of the lung may need to be managed by a major resection
• for rapid control of bleeding if pulmonary tractotomy fails.
• Depending upon the patient’s anatomy, the fissures can simply be divided with scissors, and any air leaks and bleeding can be controlled following resection. Alternatively, the fissures can be divided using staplers. Reticulating staplers may be advantageous in open-lung resection.
• Trauma pneumonectomy has been associated with a very high mortality (> 90 percent), with two major reasons:
• The procedure is usually performed late and as a desperate attempt to control hilar bleeding after other techniques have failed.
• The combination of shock and clamping of the pulmonary artery results in almost irreversible right heart failure.