[A new operative technique for pulmonary artery banding: adjustment of pulmonary artery bands by mitral valve flow velocity].

We developed a new technique to adjust the pulmonary artery band at surgery by monitoring the mitral valve flow velocity, which is indirectly indicative of the pulmonary flow. We employed this technique for 10 consecutive patients aged from 5 days to 5 months (mean, 1 months) weighing from 2.7 to 4.4 kg (mean, 3.3 kg). Underlying disease was aortic coarctation or interrupted+ventricular septal defect in 7 patients, single ventricule in 1 patients and miscellaneous defects in 2 patients. The pulmonary artery was exposed through a left lateral thoracotomy and a 3 mm wide Teflon tape was placed around the main pulmonary artery. The transducer of the Doppler echocardiography was placed along the left sternal border. The band was tightened gradually until the maximum velocity of the mitral valve flow decreased to around 70% of the previous level. During banding procedure, arterial oxygen saturation, heart rate and left ventricular contractility were monitored continuously. If bradycardia, unacceptable hypoxemia or ventricular dysfunction occurred, the band was released. The mitral valve flow velocity decreased rapidly by just a little additional tightness of the band between the range of 50% to 80% of the previous level. This technique enabled a very fine adjustment (less than 0.5 mm plication) and postoperative management has become very easy. Although there is a limitation of this technique that monitoring of the mitral valve flow velocity cannot be applied to the patients with significant interatrial shunt or mitral regurgitation, we conclude that this technique is simple and useful to obtain the optimum constriction of the pulmonary artery with excessive pulmonary blood flow.