Outcome after extended arch repair for aortic coarctation.

OBJECTIVES: To assess survival and long term arch patency rates in a consecutive group of children after extended arch repair for coarctation of the aorta. METHODS: Review of 191 consecutive children (154 (81%) under 1 year of age) operated on between 1990 and 2002 by a single surgeon using extended arch reconstructive techniques. For assessment of survival patients were divided into three groups: 1, coarctation alone, n = 104; 2, coarctation and ventricular septal defect, n = 38; and 3, coarctation in association with complex intracardiac anomalies, n = 49. A prospective and systematic clinical and echocardiographic evaluation of the aortic arch was undertaken. RESULTS: Median time to follow up was 4.2 years (range 1-10.6 years). Overall actuarial survival was 92%, 88%, and 88% at two, five, and 10 years. Mortality was significantly higher in those patients with complex intracardiac anatomy. Arch obstruction recurred in seven of 165 (4.2%) patients: four of 139 (2.9%) term and three of 10 (30%) premature infants (p < 0.001). CONCLUSIONS: Survival after extended arch reconstruction for coarctation is excellent. At long follow up recurrent arch obstruction is rare, with prematurity the only risk factor.

Alveolar recruitment strategy improves arterial oxygenation after cardiopulmonary bypass.

Atelectasis occurs during general anaesthesia. This is partly responsible for the impairment of gas exchange that occurs peri-operatively. During cardiopulmonary bypass, this atelectasis is exacerbated by the physical collapse of the lungs. As a result, poor arterial oxygenation is often seen postoperatively. We tested the effect of an 'alveolar recruitment strategy' on arterial oxygenation in a prospective randomised study of 78 patients undergoing cardiopulmonary bypass. Patients were divided equally into three groups of 26. Group 'no PEEP' received a standard post bypass manual lung inflation, and no positive end-expiratory pressure was applied until arrival at intensive care unit. Group '5 PEEP' received a standard post bypass manual inflation, and then 5 cmH2O of positive end-expiratory pressure was applied and maintained until extubation on intensive care. The third group, 'recruitment group', received a pressure-controlled stepwise increase in positive end-expiratory pressure up to 15 cmH2O and tidal volumes of up to 18 ml x kg(-1) until a peak inspiratory pressure of 40 cmH2O was reached. This was maintained for 10 cycles; the positive end-expiratory pressure of 5 cmH2O was maintained until extubation on intensive care. There was a significantly better oxygenation in the recruitment group at 30 min and 1 h post bypass when compared with the no PEEP and 5 PEEP groups. There was no significant difference in any of the groups beyond 1 h. Application of 5 cmH2O positive end-expiratory pressure alone had no significant effect on oxygenation. No complications due to the alveolar recruitment manoeuvre occurred. We conclude that the application of an alveolar recruitment strategy improves arterial oxygenation after cardiopulmonary bypass surgery.

Pleuro-biliary fistula from a ruptured choledochal cyst.

We present a case of rupture of an intrahepatic choledochal cyst through the diaphragm resulting in a pleuro-biliary fistula and a right pleural empyema which was surgically treated. Hepatobiliary complications resulting in biliary empyema of the pleura are discussed.

Mitral valve surgery using a modified superior left atrial approach.

Most surgeons use a longitudinal right lateral left atrial incision behind the inter-atrial groove for the exposure of the mitral valve, even though several other surgical techniques have been described. The shortest route to the mitral valve is, however, through the roof of the left atrium, where the incision is closest to the mitral annulus. This was first described by Meyer et al., but the approach became unpopular because of its technical difficulties and inadequacies. We have modified this technique, making it safer, easier and adaptable to any type of mitral surgery. We describe our experience with 53 patients who had mitral valve surgery using this modified approach. All of the operations were performed by the same surgeon over an 18 month period with consistently satisfactory results.

Total coronary artery revascularization through a mini-sternotomy.

Revascularization of all significantly stenosed vessels remains the goal of coronary artery bypass surgery. Recent improvements in endoscopic instruments have resulted in the evolution of selective left anterior descending artery bypass grafting through a limited anterior small thoracotomy (LAST) incision. A major limitation of this technique is the inaccessibility for complete surgical revascularization in multivessel disease. In this article, we describe a minimally invasive technique for total coronary artery revascularization that combines conventional surgical techniques with the advantages of minimally invasive surgery. We have performed total coronary revascularization in 52 patients over a period of 16 months with consistently good results.

Chaotic motion in an oscillatory boundary layer.

The chaotic time oscillations in an incompressible fluid driven into motion by a harmonic time-varying pressure gradient is examined. Special attention is given to centrifugal destabilization of the viscous boundary layer. The basic flow is shown to be linearly unstable. For increasing modulation amplitude, the flow exhibits chaotic oscillations. The energy exchange between subharmonics and superharmonics of the least-stable spanwise wave number is considered. The presence of subharmonic Fourier modes are shown to accelerate the transition to temporally chaotic motion. (c) 1996 American Institute of Physics.