Early Echocardiographic Diagnosis of Aorto-Right Ventricular Fistula During Emergent Surgery for Penetrating Precordial Trauma

Abstract

CASE REPORT A 20-year-old man was admitted in our trauma center after being stabbed with a small-bladed stiletto knife in the left hemithorax. The patient had no medical history. At the scene, the patient presented no hemodynamic or respiratory distress. Bleeding from the thoracic wound was moderate and no hemoptysis was found. During transportation to the hospital, the patient rapidly developed hemodynamic instability and received a continuous infusion of norepinephrine from the mobile medical team. At the admission to the hospital, the patient was alert and responsive, despite a very low-blood pressure (60/40 mm Hg). No other sign suggesting cardiac tamponade as distension of jugular vein or paradoxical pulse were present. The patient showed a 1.5-cm horizontal stab wound in the left parasternal region at 5 cm of sternum in the left-fourth intercostal space. A transthoracic echocardiography was immediately performed at the bedside showing circumferential pericardial effusion with diastolic right ventricular (RV) collapse indicating a cardiac tamponade. A median thoracotomy was performed, the pericardium was opened, and an important pericardial effusion was evacuated followed by a dramatic increase of blood pressure. A transmural injury of RV anterior free wall was closed. At the end of surgery the patient was stable, with no active bleeding. No thrill at palpation of the right ventricle could be detected. A transesophageal echocardiography (TEE) was performed showing a false signal jet (spectral folding in color Doppler with lowering of pulse repetition frequency for high frequencies caused by an acceleration of flow at the exit of the stenosis on the level of the fistula) in the RV outflow tract (Fig. 1). A mid esophageal atrioventicular long axis 130° view revealed a high-velocity jet between the aorta and the RV during the whole cardiac cycle. No aortic or tricuspid injury was observed (Fig. 2). The fistula was significant enough to require another immediate repair with cardiopulmonary bypass. Electromechanical arrest was achieved with antegrade cardioplegia. Two different lesions could be found and repaired: one was located at the right coronary sinus and the second one at posterior part of the right ventricle free wall. The initial follow-up was eventless. At day 13, physical examination revealed a new heart murmur leading to a new transthoracic echocardiography and a diagnosis of recurring aortoventricular fistula at the same location, probably due to inefficacy of the first sutures. A new intervention was equally performed by cardiopulmonary bypass and satisfactory result was checked by TEE examination. Hospital discharge was obtained at day 25 with good cardiac function recovery.