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Penetrating cardiac trauma is typically life-threatening and often requires urgent surgical intervention. Penetrating injury can cause damage in more than 1 cardiac structure that may be difficult to identify at the initial urgent operation. We describe the case of a young man in whom a perimembranous ventricular septal defect and perforation of the anterior leaflet of the mitral valve were caused by a screwdriver wound.
Cardiac injury by a penetrating instrument is not always limited to the free wall of the heart or the great arteries; it may also involve the interventricular and interatrial septa, cardiac valves, coronary arteries, and conduction system.1–3 Because little time and little diagnostic information are available before an urgent operation, patients with penetrating cardiac injuries may require additional surgery to repair injuries not found during the acute stabilization process. We report the case of a patient in whom repair of a perimembranous ventricular septal defect (VSD) and mitral valve perforation was delayed 1.5 months after the initial surgery for penetrating cardiac trauma.
In November 2000, a 19-year-old man with no relevant medical history was stabbed with a screwdriver in the left 5th intercostal space during a street fight. After 1 hour, he was admitted with syncope to the emergency service of another hospital. Initial evaluation at that institution revealed dyspnea and hypotension. Chest radiography showed a left-sided submassive collection from which an inserted chest tube drained 1,500 cc of blood. The patient underwent emergency exploratory surgery via a left anterior thoracotomy. A perforation was noted in the right ventricle, and a small amount of blood was seen in the pericardial cavity. The perforation was repaired with direct suture closure using Teflon pledgets. No other cardiac injury was noted at the time of that operation, during which intraoperative echocardiography was not performed due to the unavailability of this diagnostic technique at that hospital. One week later, the patient was noted to have a new cardiac murmur, and he was transferred to our hospital for further assessment.
On arrival at our hospital, the patient was pale and was experiencing chest pain and shortness of breath. Evaluation revealed a blood pressure of 110/60 mmHg, a pulse rate of 100 beats/min, and a respiratory rate of 20 breaths/min. There was a pronounced precordial systolic thrill, and a harsh 5/6 systolic murmur was heard at the left sternal border, with radiation to the axilla. There were no signs of right heart failure. Chest radiography revealed mild cardiomegaly and no pleural effusion. The electrocardiogram showed sinus tachycardia and nonspecific ST-T changes. Hemoglobin (8.5 g/dL) and hematocrit (25.0%) were the only abnormal values in the blood sample.
Two-dimensional transthoracic echocardiography (TTE) showed perforations in both the membranous interventricular septum (diameter, 5.0 mm) and the mitral anterior leaflet (Fig. 1). There was a left-to-right shunt and moderate mitral regurgitation, as shown by color-flow Doppler echocardiography (Fig. 2). These findings were confirmed by transesophageal echocardiography (TEE). Cardiac catheterization and coronary angiography revealed a left-to-right shunt ratio of 1.5:1, moderate mitral regurgitation, and normal coronary arteries.
Operative intervention was undertaken for the repair of these acquired lesions, 1.5 months after the injury. A standard median sternotomy was performed, and cardiopulmonary bypass with moderate hypothermia was instituted using aortobicaval cannulation and antegrade administration of blood for cardioplegia. Inspection of the mitral valve via left atriotomy revealed a 5.0-mm perforation in the anterior leaflet (Fig. 3), which was repaired with a glutaraldehyde-treated pericardial patch. After right atriotomy, another 5.0-mm defect was found in the membranous septum (Fig. 4). This VSD was closed with sutures, primarily via an incision in the right atrium through the tricuspid valve. De-airing maneuvers were applied after the closure of the right and left atriotomies, and the aortic cross-clamp was removed. Intraoperative TEE showed no residual left-to-right shunt or mitral regurgitation. Cardiopulmonary bypass was terminated with no complication. Extubation was performed 4 hours postoperatively. The patient was discharged from the hospital on the 5th postoperative day. At a 1-month clinical follow-up, he was doing well, without dyspnea or activity limitation.
Penetrating chest trauma, usually due to stab or gunshot wounds,4,5 can produce a wide variety of cardiac injuries. In addition to the free wall of the heart or the great arteries, penetrating cardiac injury may involve the interventricular and interatrial septa, cardiac valves, conduction system, and coronary arteries.1,2,6,7
The incidence of intracardiac lesions in patients available for follow-up after heart injury varies markedly (from 4% to 56%) in different series and depends greatly on the criteria used for the selection of patients for further investigation.8 Ventricular septal defect has been the most frequent injury, followed by communication between the aorta and right ventricle or atrium, and, less often, damaged atrioventricular or semilunar valves. The combination of a VSD and mitral valve injury after penetrating cardiac trauma is a rare but previously described complication. Skoularigis and associates6 reported the incidence of subsequently found intracardiac lesions in patients who had survived a penetrating cardiac injury to be 20.9% (9 of 43). Of these patients, five had solitary lesions and four had multiple lesions, including muscular-type VSD with perforation of the anterior mitral valve leaflet.
Suspicion of intracardiac injury is usually raised by persistent hemodynamic instability or the incidental discovery of a cardiac murmur. Many of these lesions become clinically detectable only at a later stage, sometimes weeks later, when the defect has become larger after resolution of surrounding edema, lysis of an occluding clot, fibrous retraction of the edges, or ventricular enlargement.9 For the same reasons, detection of such defects at the time of initial evaluation can be extremely difficult, even with TEE.
Echocardiography can rapidly provide a high level of diagnostic accuracy and is therefore especially useful preoperatively when cardiac trauma is strongly suspected. It can provide both the diagnosis and the anatomic details that may be of value in guiding the surgical approach.10,11 In some patients with severe hemodynamic compromise, there may not be sufficient time for echocardiography; with less severely ill patients, this examination should probably take no longer than 30 minutes. Chest wounds that occur in the usual transducer positions, and the presence of other thoracic injuries, including pneumothorax, can make an adequate transthoracic examination technically impossible.
The clinical picture of a penetrating wound of the heart depends on several factors, including the object responsible for the injury, the site of the wound, and the precise location of the structures injured. The nature of the pericardial wound is important. If the pericardium remains open and extravasated blood can pass freely into the pleural cavities or mediastinum, cardiac tamponade will not develop, at least initially, and the presenting signs and symptoms will be those of hemorrhage and hemothorax, as in our patient. On the other hand, if the pericardium does not permit free drainage, tamponade may occur within minutes, or hours later. In some instances, blood accumulates both intra- and extrapericardially.12
Most patients with penetrating cardiac injuries die before receiving medical care. In the small group of patients who receive medical attention, the most important factors for survival are rapid diagnosis and immediate treatment.13 Such patients can be hemodynamically unstable, which renders initial exploration difficult. Most authorities14–16 recommend initial, urgent repair of only life-threatening injuries, followed by delayed elective repair of septal defects and valvular injuries if clinically indicated. However, in the presence of severe structural injury that cannot be hemodynamically tolerated, the initial repair should probably include such intracardiac damage as well—particularly if the mitral valve is involved.16 Intraoperative TEE may then be helpful to define the nature of the valvular (or other structural) lesions accurately. Because our patient had undergone urgent surgery at another institution, which lacked TEE, we had to perform a 2nd reparative surgery.
Generally, a left anterolateral thoracotomy in the 5th intercostal space, which provides very rapid access to the right and left ventricles and to the pulmonary artery, is the incision of choice in hemodynamically unstable patients.15,16 However, in stable patients or in patients with gunshot wounds, which frequently involve multiple cardiac chambers, median sternotomy is the strongly favored approach.17 In such cases, median sternotomy, with its provision of much better surgical exposure, enables the surgeon to perform a comprehensive evaluation and repair of nearly any damaged intracardiac part. Use of intraoperative TEE can facilitate this approach.
Prompt identification of complex injuries is essential for proper timing of surgical intervention and prevention of long-term sequelae. The appropriate timing of surgical repair—whether the repair is delayed until a secondary operation or not—is difficult in patients with multiple injuries and depends on the patient's cardiac function after the injury.16 In such cases, TEE has been recommended as the method of choice, because it enables accurate definition of the nature of the valve or septal lesions and the underlying cardiac function.18 Delayed repair of cardiac trauma promotes tissue healing to a varying degree, which may or may not be beneficial, depending on the type of injury. Ventricular septal defects can shrink or even spontaneously close with time, but this is unlikely to occur with atrioventricular valve injuries.7,19 For the latter, delayed intervention can result in excessive fibrosis, shortening of chordae tendineae, and damage to the leaflets beyond repair, so that the valve must be replaced.7 In our patient, the VSD was small, with a left-to-right shunt ratio of less than 2:1. Therefore, the main reason for performing the 2nd surgery was to repair the mitral valve perforation. Hemodynamically insignificant, isolated VSDs with a low left-to-right shunt ratio can be followed up with echocardiography.
In conclusion, patients who sustain penetrating trauma to the heart should undergo hemodynamic stabilization and thorough investigation for multiple intracardiac injuries. Transthoracic and transesophageal echocardiography are the techniques of choice for prompt diagnosis. These methods can identify most possible injuries, including septal and valvular lesions. Surgical repair should be performed for hemodynamically significant lesions, and repair of leaflet injuries should not be delayed excessively; a lengthy delay could lead to damage sufficient to require replacement.
Address for reprints: Kerim Cagli, MD, Kirkkonaklar mah. Semsettin Gunaltay cad. 17. Sok. No:1/13, 06610 Cankaya-Ankara, Turkey E-mail: moc.liamtoh@ilgacmirek