Chapter 14 Operative Exposure in Thoracic Trauma: Exposure of the Great Vessels

This chapter will present the exposure of actual or suspected injuries of the great vessels of the chest.

Learning Objectives

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

1. Describe and demonstrate appropriate positioning and incisions to expose the ascending, arch, and descending thoracic aorta.
2. Demonstrate surgical exposure of the ascending aorta, aortic arch, and descending thoracic aorta.
3. Demonstrate exposure of the innominate vessels.
4. Demonstrate surgical exposure of the carotid artery at its origin.
5. Demonstrate resection of the clavicular head.
6. Demonstrate surgical exposure of the subclavian vessels.
7. Describe damage control techniques for thoracic injuries.

Considerations

• Patients with injuries to the great vessels usually present with immediate, life-threatening hemorrhage. Prompt diagnosis and treatment by experienced practitioners is essential to the successful management of these injuries.
• When time permits, engaging the assistance of appropriate specialists (cardiothoracic or vascular surgeons and/or interventional radiologists) may be helpful.
• Successful surgical repair of major thoracic vascular injuries requires decisive action including adequate exposure, rapid vascular control, and effective repair.
• Although digital control can temporize almost any bleeding, repair requires adequate proximal and distal vascular exposure.
• Ligation and shunting are both viable options in unstable patients. The proximal subclavian artery can be ligated distal to the thoracoacromial trunk. Carotid injuries should be shunted if possible. Venous injuries can usually be ligated.
• Remember the close proximity to the vasculature of the vagus, recurrent laryngeal, and phrenic nerves, as well the thoracic duct. Grasping large amounts of adjacent tissue while focusing on vascular structures may cause injury to these nearby structures.

Incisions in General

• The surgeon should make strategic decisions on positioning, exposure, and control based on the suspected injury pattern.
• The placement and size of the incision is the foundation for success. The patient’s stability will dictate the incision to be made.
• Patients in extremis from penetrating thoracic injuries must undergo immediate resuscitative thoracotomy via an anterolateral thoracotomy and, if needed, extension across the right chest as a “clamshell” incision (Figures 1 and 2), as described in chapter 10.
• If the patient is not in extremis, the most appropriate incision is dictated by the structure(s) most likely to be injured.
• Anterior wounds in a stable patient are best approached through a median sternotomy (Figure 3). The innominate (brachiocephalic) vein (Figure 3) crosses anterior to and obscures the origin of the arch vessels. This structure can be divided and ligated to facilitate exposure.

• A median sternotomy can be extended into the neck or above the clavicle (Figure 4) to expose and manage injuries to the thoracic outlet vessels. As such, it is important to place the sternal retractor with the bar toward the feet (Figure 3) to allow extension of the incision above the sternal notch.
• Lateral and posterior wounds may be better visualized via a posterolateral thoracotomy, but this should only be done in a stable patient in whom other life-threatening injuries in the abdomen and chest have been ruled out.
• Be flexible, and extend or create new incisions as needed. Make a decision, make an incision. If it’s the wrong incision, make a bigger or another incision.

Exposure of Specific Injuries

Thoracic Aorta

• Injuries to the ascending aorta and aortic arch are usually exposed and managed through a median sternotomy with an appropriate superior extension (Figures 3 and 4). As previously discussed, in unstable patients, a “clamshell” thoracotomy may be indicated and will provide excellent exposure (Figure 2).
• The ascending aorta is largely intrapericardial, with the superior pericardial reflection occurring at the level of the innominate artery takeoff. The anterior and right lateral aspects of the ascending aorta are more readily accessible. The left lateral border of the ascending aorta is adherent to the pulmonary artery, making it prone to inadvertent injury.
• Injuries to the descending thoracic aorta in a stable patient are ideally managed via endovascular approaches or by a left posterolateral thoracotomy (Figures 5 and 6).
• After the chest has been entered during a posterolateral thoracotomy, the lung is retracted (or deflated using a double lumen tube or bronchial blocker), providing exposure of the descending thoracic aorta. The aortic arch and left subclavian artery can be exposed and controlled, taking care to avoid the vagus nerve (Figure 7).
• For injuries to the distal ascending aorta and aortic arch, the key maneuver is mobilization of the aortic arch. The pericardium is opened, and the left innominate vein is identified. The superior pericardial reflection is dissected from the aorta, and the innominate vein is divided to facilitate exposure.
• Injuries to the descending aorta can be controlled with a partial occluding clamp or between two vascular clamps.
• For through-and-through wounds, identification of both wounds is mandatory. This may require surgical extension of the injury or transection of the aorta with subsequent repair.

Innominate Artery and Vein

• Median sternotomy is usually the incision of choice, but the “clamshell” can also provide excellent exposure of this region in patients in extremis (Figure 8).
• Deliberate division of the left innominate vein provides further exposure of the arch vessels.
• Injuries at the aorto-innominate junction may require resection and bypass from the ascending aorta.
• Based upon their location and complexity, innominate artery injuries can be managed with simple repair, interposition grating, or jump grafts from the proximal aorta.

Carotid Artery

• Injuries in the neck are best approached through an incision along the sternocleidomastoid muscle. This approach is described in chapter 7.
• For injuries with obvious thoracic involvement, the proximal carotid arteries are exposed through an extension of a median sternotomy along the anterior border of the sternocleidomastoid muscle on the appropriate side of the neck (Figure 9). A partial sternotomy (division of the manubrium) may be adequate to achieve this exposure (Figures 9 and 10).

Subclavian Vessels

• As their name implies, the subclavian vessels are well hidden behind the clavicle. A variety of exposure techniques have been described for proximal and distal control.
• In stable patients with suspected subclavian artery injury, consideration should be given to endovascular techniques to control hemorrhage. If the patient is unstable and actively bleeding, prompt surgical exposure and control is vital.
• Proximal exposure and control needs to be obtained through the chest; the site for distal control is tailored to the site and extent of the injury.

Proximal Exposure of the Subclavian Artery

• Proximal exposure and control of the right subclavian can be achieved via a median sternotomy.
• Proximal exposure and control of the left subclavian artery is challenging due to its posterior course.
  • One well-described method of obtaining proximal control of the left subclavian is to perform an anterior thoracotomy in the left third intercostal space (Figure 11). However, in muscular individuals with a well-developed pectoralis major muscle—or in the setting of other intrathoracic injuries—this incision may be inadequate.
  • In unstable trauma patients, the initial approach may be a resuscitative thoracotomy at the fifth interspace, extended across to a “clamshell” incision; this provides excellent access to the origin of both subclavian arteries for proximal control (Figure 12).

Exposure of the Subclavian Artery above the Clavicle (Supraclavicular Approach)

• Distal control of both subclavian arteries (or proximal control of axillary artery injuries) can be obtained using a supraclavicular approach. The exposure is easier on the right side than the left, as the course of the subclavian artery is deeper on the left.
• To expose the subclavian artery above the clavicle, an incision is made parallel to and 1 cm above the medial half of the clavicle (Figure 13).
• This incision is carried down through the platysma, and the attachment of sternocleidomastoid to the clavicle is divided about 1 cm from the clavicle to expose the underlying internal jugular vein and the scalene fat pat (Figure 14).
• The anterior scalene muscle, which lies between the subclavian vein and the subclavian artery, is exposed. The phrenic nerve, which courses obliquely from the superior lateral to the inferior medial aspect of the muscle, is identified and preserved (Figure 15).
• The anterior scalene muscle is divided about 1 cm from the clavicle to expose the underlying subclavian artery, which can then be controlled (Figure 16).
• If the subclavian artery is followed medially, the vertebral artery can be identified, as described in chapter 9.

Resection of the Clavicle to Expose the Subclavian Artery

• If the desired exposure of the subclavian vessels is not achieved via sternotomy and extension above the clavicle or into the neck, a portion of the clavicle can be removed.
• An incision is made down onto the anterior surface of the clavicle, which is then cleared circumferentially of the surrounding tissues. A perforating towel clamp is used to grasp the clavicular head, and then a Gigli saw is used to divide the clavicle in its mid portion (Figures 17 and 18).
• The sternal head of the clavicle is dissected free, and the portion of clavicle is removed to allow exposure of the underlying structures (Figures 19–21).
• Alternatively, the clavicle can be divided near the sternum and retracted laterally.
• The clavicle can be replaced and wired once the vascular issues have been resolved, but this is not mandatory.

• The clavicle is generally removed as an extension of sternotomy for exposure of the proximal vessels in the chest, but if control in the chest is not needed, the subclavian vessels can also be exposed via resection of the clavicle without sternotomy (Figures 21 and 22).
• Though clavicular resection without sternotomy can provide exposure to the subclavian vessels, more proximal control is generally required with the addition of the median sternotomy providing full access to the great vessels in the chest and the root of the neck as seen in Figure 23.