The case of a 13-year-old child (weight, 38 kg; height, 150 cm; body surface area, 1.23 m 2 ; body mass index, 16.9 kg/m 2 ), undergoing mitral prosthesis replacement through a minithoracotomy using the port-access platform, 1,2 is reported. The patient had undergone 3 previous cardiac surgeries.At the age of 8 months, the patient underwent correction of an anomalous left coronary artery originating from the pulmonary artery trunk with the Takeuchi procedure, and a mitral valve repair with the Kay technique. At 2 years of age, he underwent reoperation for a posterior leaflet extension with a pericardial patch as a result of severe mitral regurgitation. A few months later the mitral valve was replaced with a mechanical prosthesis (17 mm; St Jude Medical, St Paul, Minn) for severe residual insufficiency. All previous procedures were performed through a longitudinal median sternotomy. At 13 years of age, the patient came to our attention for onset and worsening of dyspnea (New York Heart Association class II-III). Upon physical examination, a diastolic precordial murmur was found. A mean gradient of 12 mm Hg was measured by transthoracic echocardiography with normal movement of both prosthesis disks.Given these echocardiographic findings and symptoms, the indication for mitral prosthesis replacement was confirmed. Feasibility, safety, and efficacy of redo cardiac surgeries in adults using a mini-invasive port-access platform has been reported previously by many investigators, 2-4 but the application of this approach to small children rarely has been described. 5 Mini-invasive approaches, especially in reoperations, bear the disadvantage of femoral venous and arterial cannulation. This can be a serious problem in the case of small vessels, such as in pediatric patients.In this particular case, considering the patient's previous surgical history, transthoracic aortic cross-clamping was not possible. Ventricular fibrillation with an unclamped ascending aorta was an option. Nevertheless, there is evidence of increased neurologic events in adults after fibrillatory heart surgery, independently correlated with a minithoracotomy. For these reasons we explored the possibility of aortic clamping with a peripheral endoaortic balloon catheter, as we routinely do in adults.A precise and detailed evaluation of the aortic-iliac and femoral vessels was performed. In particular, the femoral artery size (right, 6.0 mm, Figure 1, A; left, 6.6 mm, Figure 1, B), the diameter of the ascending aorta (22 mm), and the distance between the origin of the left coronary artery, which was more cranial than usual because of the previous Takeuchi procedure, and the brachiocephalic artery (31 mm, Figure 1, C) were measured using computed tomography scan and magnetic resonance imaging (Figure 1, D). Measurements were obtained to ascertain the possibility of performing endoaortic clamping and to identify the correct position of where to inflate the balloon, avoiding the obstruction of the left coronary artery or of the anonimus trunk. In this cas...