The optimal benefit of EDT is achieved by a surgeon experienced in the management of intrathoracic injuries. The emergency physician, however, should not hesitate to perform the procedure in the moribund patient with a penetrating chest wound when thoracotomy is the only means of salvage. The technical skills needed to perform the procedure include the ability to perform a rapid thoracotomy, pericardiotomy, cardiorrhaphy, and thoracic aortic cross-clamping; familiarity with vascular repair techniques and control of the pulmonary hilum are advantageous. Once life-threatening intrathoracic injuries are controlled or temporized, the major challenge is restoring the patient’s hemodynamic integrity and minimizing vital organ reperfusion injury.
A left anterolateral thoracotomy incision is preferred for EDT. Advantages of this incision in the critically injured patient include (a) rapid access with simple instruments, (b) the ability to perform this procedure on a patient in the supine position, and (c) easy extension into the right hemithorax, a clamshell thoracotomy, for exposure of both pleural spaces and anterior and posterior mediastinal structures. The key resuscitative maneuvers of EDT, namely, pericardiotomy, open cardiac massage, and thoracic aortic cross-clamping are readily accomplished via this approach. The initial execution of a clamshell thoracotomy should be done in hypotensive patients with penetrating wounds to the right chest. This provides immediate, direct access to a right-sided pulmonary or vascular injury while still allowing access to the pericardium from the left side for open cardiac massage. Clamshell thoracotomy may also be considered in patients with presumed air embolism, providing access to the cardiac chambers for aspiration, coronary vessels for massage, and bilateral lungs for obliteration of the source.
Preparation for EDT should be performed well ahead of the patient’s arrival. Set-up should include a 10-blade scalpel, Finochietto’s chest retractor, toothed forceps, curved Mayo’s scissors, Satinsky’s vascular clamps (large and small), long needle holder, Lebsche’s knife and mallet, and internal defibrillator paddles. Sterile suction, skin stapler, and access to a variety of sutures should be available (specifically 2-0 prolene on a CT-1 needle, 2-0 silk ties, and teflon pledgets). Upon patient arrival and determination of the need for EDT, the patient’s left arm should be placed above the head to provide unimpeded access to the left chest. The anterolateral thoracotomy is initiated with an incision at the level of the fifth intercostal space (Fig. 14-2). Clinically, this level for incision corresponds to the inferior border of the pectoralis major muscle, just below the patient’s nipple. In women, the breast should be retracted superiorly to gain access to this interspace, and the incision is made at the inframammary fold. The incision should start on the right side of the sternum; if sternal transection is required, this saves the time-consuming step of performing an additional skin incision. As the initial incision is carried transversely across the chest, and one passes beneath the nipple, a gentle curve in the incision toward the patient’s axilla rather than direct extension to the bed should be performed; this curvature in the skin correlates with the natural curvature of the rib cage. The skin, subcutaneous fat, and chest wall musculature are incised with a knife to expose the ribs and associated intercostal space. Intercostal muscles and the parietal pleura are then divided in one layer either with curved Mayo scissors or sharply with the scalpel; the intercostal muscle should be divided along the superior margin of the rib to avoid the intercostal neurovascular bundle. Chest wall bleeding is minimal in these patients and should not be a concern at this point in the resuscitation. Once the incision is completed and the chest entered, a standard Finochietto’s rib retractor is inserted, with the handle directed inferiorly toward the axilla (Fig. 14-2). Placement of the handle toward the bed rather than the sternum allows extension of the left thoracotomy into a clamshell thoracotomy with crossing of the sternum without replacing the rib retractor.
(A) and (B) The thoracotomy incision is performed through the fourth or fifth intercostal space; the incision should start to the right of the sternum, and begin curving into the axilla at the level of the left nipple. The Finochietto’s rib retractor is placed with the handle directed inferiorly toward the bed.
If the left anterolateral thoracotomy does not provide adequate exposure, several techniques may be employed. The costal cartilages can be readily divided with heavy scissors. Alternatively, the sternum can be transected for additional exposure with a Lebsche’s knife; care must be taken to hold the Lebsche’s knife firmly against the underside of the sternum when using the mallet to forcefully transect the sternum, or the tip of the instrument may deviate and result in an iatrogenic cardiac injury. If the sternum is divided transversely, the internal mammary vessels must be ligated when perfusion is restored; this may be performed using either a figure of eight suture with 2-0 silk or by clamping the vessel with a tonsil and individually ligating it with a 2-0 silk tie (Fig. 14-3). A concomitant right anterolateral thoracotomy produces a “clamshell” or “butterfly” incision, and achieves wide exposure to both pleural cavities and anterior and posterior mediastinal structures (Fig. 14-4). Once the right pleural space is opened, the rib retractor should be moved to more of a midline position to enhance separation of the chest wall for maximal exposure. When visualization of penetrating wounds in the aortic arch or major branches is needed, the superior sternum is additionally split in the midline.
(A) and (B) Transverse division of the sternum requires individual ligation of the internal mammary arteries.
(A) and (B) A bilateral anterolateral (“clamshell”) thoracotomy provides access to both thoracic cavities including the pulmonary hila, heart, and proximal great vessels.
Pericardiotomy and Cardiac Hemorrhage Control
The pericardium is incised widely, starting at the cardiac apex and extending toward the sternal notch, anterior and parallel to the phrenic nerve (Fig. 14-5). If the pericardium is not tense with blood it may be picked up at the apex with toothed forceps and sharply opened with scissors. If tense pericardial tamponade exists, a knife or the sharp point of a scissors is often required to initiate the pericardiotomy incision. Blood and blood clots should be completely evacuated from the pericardium. The heart should be delivered from the pericardium by placing the right hand through the opening in the pericardium posterior to the heart, encircling the right side of the heart and pulling it into the left chest. This effectively places the left side of the pericardium behind the heart allowing access to the cardiac chambers for repair of cardiac wounds and access for effective open cardiac massage.
(A) and (B) Pericardiotomy is done with toothed pickups and curved Mayo scissors; the incision begins at the cardiac apex, anterior to the phrenic nerve, and extends on the anterior surface of the heart toward the great vessels.
Prompt hemorrhage control is paramount for a cardiac injury. In the beating heart, cardiac bleeding sites should be controlled immediately with digital pressure on the surface of the ventricle and partially occluding vascular clamps on the atrium or great vessels. Efforts at definitive cardiorrhaphy may be delayed until initial resuscitative measures have been completed. In the nonbeating heart, cardiac repair is done prior to defibrillation and cardiac massage. Cardiac wounds in the thin walled right ventricle are best repaired with 3-0 nonabsorbable running or horizontal mattress sutures. Buttressing the suture repair with Teflon pledgets is ideal for the thinner right ventricle, but not essential. When suturing a ventricular laceration, care must be taken not to incorporate a coronary vessel into the repair. In these instances, vertical mattress sutures should be used to exclude the coronary and prevent cardiac ischemia. In the more muscular left ventricle, control of bleeding can occasionally be achieved with a skin-stapling device if the wound is a linear stab wound whose edges coapt in diastole. Low-pressure venous, atrial, and atrial appendage lacerations can be repaired with simple running or purse string sutures. Posterior cardiac wounds may be particularly treacherous when they require elevation of the heart for their exposure; closure of these wounds is best accomplished in the OR with optimal lighting and equipment. For a destructive wound of the ventricle, or for inaccessible posterior wounds, temporary inflow occlusion of the superior and inferior vena cava may be employed to facilitate repair (see Chapter 26). BioGlue® may be used as a hemostatic agent in such cases. Use of a Foley catheter for temporary occlusion of cardiac injuries has been suggested; in our experience this may inadvertently extend the injury due to traction forces.
Advanced Cardiac Life Support Interventions Including Cardiac Massage
The restoration of organ and tissue perfusion may be facilitated by a number of interventions.56 First, a perfusing cardiac rhythm must be established. Early defibrillation for ventricular fibrillation or pulseless ventricular tachycardia has proven benefit, and evidence supports the use of amiodarone (with lidocaine as an alternative) following epinephrine in patients refractory to defibrillation. Magnesium may be beneficial for torsades de pointes; other dysrhythmias should be treated according to current guidelines.56 Familiarity with the internal cardiac paddles and appropriate charging dosages in joules is required (Fig. 14-6). In the event of cardiac arrest, bimanual internal massage of the heart should be instituted promptly (Fig. 14-7). We prefer to do this with a hinged clapping motion of the hands, with the wrists apposed, sequentially closing from palms to fingers. The ventricular compression should proceed from the cardiac apex to the base of the heart. The two-handed technique is strongly recommended, as the one-handed massage technique poses the risk of myocardial perforation with the thumb.
(A) and (B) Internal paddles for defibrillation are positioned on the anterior and posterior aspects of the heart.
(A) and (B) Open cardiac massage is performed with a two-handed hinged technique; the clapping motion sequentially closes the hands from palms to fingers.
Pharmacologic adjuncts to increase coronary and cerebral perfusion pressure may be needed. The first agent in resuscitation at this juncture is intracardiac epinephrine. Epinephrine should be administered using a specialized syringe, which resembles a spinal needle, directly into the left ventricle. Typically, the heart is lifted up slightly to expose the more posterior left ventricle, and care is taken to avoid the circumflex coronary during injection. Although, epinephrine continues to be advocated during resuscitation, there is a growing body of data suggesting that vasopressin may be superior to epinephrine in augmenting cerebral perfusion and other vital organ blood flow.57 Administration of calcium, while theoretically deleterious during reperfusion injury, increases cardiac contractility, and may be helpful in the setting of hypocalcemia produced by massive transfusion (see Chapter 13). Although, metabolic acidosis is common following EDT and resuscitation,58 the mainstay of therapy is provision of adequate alveolar ventilation and restoration of tissue perfusion. Sodium bicarbonate therapy has not been proven beneficial in facilitating defibrillation, restoring spontaneous circulation, or improving survival. It may be warranted following protracted arrest or resuscitation, because catecholamine receptors may be sensitized.
Thoracic Aortic Occlusion and Pulmonary Hilar Control
Following thoracotomy and pericardiotomy with evaluation of the heart, the descending thoracic aorta should be occluded to maximize coronary perfusion if hypotension (SBP < 70 mm Hg) persists. We prefer to cross-clamp the thoracic aorta inferior to the left pulmonary hilum (Fig. 14-8). Exposure of this area is best provided by elevating the left lung anteriorly and superiorly. Although, some advocate taking down the inferior pulmonary ligament to better mobilize the lung, this is unnecessary and risks injury to the inferior pulmonary vein. Dissection of the thoracic aorta is optimally performed under direct vision by incising the mediastinal pleura and bluntly separating the aorta from the esophagus anteriorly and from the prevertebral fascia posteriorly. Care should be taken in dissecting the aorta, and completely encircling it may avulse thoracic and other small vascular branches. Alternatively, if excessive hemorrhage limits direct visualization, which is the more realistic clinical scenario, blunt dissection with one’s thumb and fingertips can be done to isolate the descending aorta. Once identified and isolated, the thoracic aorta is occluded with a large Satinsky or DeBakey’s vascular clamp. If the aorta cannot be easily isolated from the surrounding tissue, digitally occlude the aorta against the spine to affect aortic occlusion. Although, occlusion of the thoracic aorta is typically performed after pericardiotomy, this may be the first maneuver upon entry into the chest in patients sustaining extrathoracic injury and associated major blood loss.
(A) and (B) Aortic cross-clamp is applied with the left lung retracted superiorly, below the inferior pulmonary ligament, just above the diaphragm. The flaccid aorta is identified as the first structure encountered on top of the spine when approached from the left chest.
Control of the pulmonary hilum has two indications. First, if coronary or systemic air embolism is present, further embolism is prevented by placing a vascular clamp across the pulmonary hilum (Fig. 14-9). Associated maneuvers such as vigorous cardiac massage to move air through the coronary arteries and needle aspiration of air from the left ventricular apex and the aortic root are also performed (Fig. 14-10). Second, if the patient has a pulmonary hilar injury or marked hemorrhage from the lung parenchyma, control of the hilum may prevent exsanguination. Hilar control can be performed by a Satinsky’s clamp, the pulmonary hilar twist, or temporarily with digital control (see Chapter 26).
(A) and (B) A Satinsky clamp is used to clamp the pulmonary hilum for hemorrhage control or to prevent further bronchovenous air embolism.
In cases of bronchovenous air embolism, sequential sites of aspiration include the left ventricle (1), the aortic root (2), and the right coronary artery (3).