Complex Cardiac Stab Wound

Abstract

A 40-year-old man who was involved in an altercation received a stab wound to the chest, medial to the left nipple. He was brought to the emergency department at Baylor University Medical Center; immediate resuscitation was started and continued in the operating room, where continued bleeding after placement of the chest tube prompted emergency thoracotomy. A bleeding wound in the right ventricle anteriorly was found, and it was closed by sutures. Although the immediate postoperative course was uneventful, mild dyspnea appeared, a systolic precordial murmur was heard, and the chest radiograph showed an enlarged right ventricular cavity. Echocardiogram showed an enlarged right atrium and ventricle and suggested an abnormal left-to-right communication or “shunt.” A transesophageal echocardiogram confirmed a left-to-right shunt and showed an aorta-to-right-ventricular-outflow-tract fistula (Figure 1), but the exact position was indeterminate. Cardiac catheterization showed elevated right-sided cardiac pressures with a 2-to-1 left-to-right shunt (Figure 2). Still, the precise location of the shunt was not determined but was thought to be near the aortic valve or in the subvalvular region of the ventricular septum. Because of the hemodynamically significant shunt, another thoracotomy was performed. Cardiopulmonary bypass and cardiac arrest were used to stop the heart, allowing direct visualization of the injury. The stab wound had entered the right ventricular cavity, having traversed its outflow tract and penetrated the ventricular septum and the aortic tissue below the right cusp of the aortic valve. The width of the patient's stab incision was approximately 1 cm. The left-ventricular-outflow-tract-to-right-ventricular-outflow-tract injury was repaired with 2 reinforced sutures placed below the aortic valve Intraoperative transesophageal echocardiogram confirmed the completed repair of the aorta-to-right-ventricular-outflow- tract fistula. The patient's convalescence was normal. Penetrating heart injuries are often fatal (10% to 60%) (1–3) and are catalogued as either gunshot wounds or stab wounds. Gunshot wounds of the heart are generally associated with 2 to 4 times the mortality of stab wounds to the heart (2,3); this is thought to be related to the surrounding tissue injury of the highvelocity projectile vs the low velocity of the stab instrument. Because of the muscular nature of the ventricular walls, traumatic incisions and lacerations (stabs) of the left ventricular wall and, to a lesser extent, the right ventricular wall, will often temporarily seal and allow time for transport to a medical center (1,3). The thin atrial walls, in contrast, seldom seal without an external force, such as a clamp or suture. External cardiac compressions usually cause profuse bleeding with tamponade and rapid death. This present case illustrates well the optimal management of a cardiac stab wound that did not cause heart failure, dysrhythmias, or myocardial ischemia. Posttraumatic intracardiac shunt is uncommon (4), but it can result in infective endocarditis ( 2.0, the incidence of eventual failure and/or dysrhythmias is high (6). Such progression to right heart failure is variable and may take more than a decade to manifest itself. Consequently, these “low” injuries are lesions in which shunt observation for a period of time is rational. By the time normal wounds are expected to fully heal (about 8 to 12 weeks), continued presence of the shunt indicates fistulization or epithelialization of the tract, and elective surgical repair is indicated. A subvalvular ventricular septal defect may cause sagging and/or damage of 1 or more aortic valve cusps and eventually cause aortic insufficiency (7). The ventricular septal defect in the present patient could be closed via aortotomy using suture alone or patch. The reinforced suture technique was employed because of its simplicity. A patch was avoided to reduce the chance of aortic valve distortion and implantation of a foreign body. The patient's normal postoperative convalescence is a testimony to the resilience of youth as well as the diligent pursuit of unusual abnormalities in a “usual” trauma patient. Care of this patient underscores one of the most important positive attributes of Baylor University Medical Center: the close and coordinated multidisciplinary efforts of the trauma surgery, cardiology, and thoracic surgery services in difficult cases.