Anatomic correction for post-mustard pulmonary venous obstruction

Successful arterial switch operation for post-Mustard pulmonary venous obstruction and secondary pulmonary hypertension

A 16-year-old girl presented with dyspnea 15 years after the Mustard operation for transposition of the great arteries with intact ventricular septum. An echocardiogram revealed secondary pulmonary hypertension due to pulmonary venous obstruction. Cardiac catheterization showed the left (pulmonary) ventricular pressure was over the systemic level. We performed a successful one-stage switch conversion. The patient is doing well 1 year after the switch conversion.

Arterial switch after failed atrial baffle procedures for transposition of the great arteries

BACKGROUND

Late failure of the systemic right ventricle after atrial baffle procedures in patients with transposition of the great arteries poses significant management problems. We reviewed our experience with staged conversion to arterial switch operation (ASO) in these patients.

METHODS

Between 1984 and 1999, 11 patients underwent pulmonary artery band (PAB) to prepare the left ventricle for ASO conversion. One additional patient had subpulmonic stenosis and was naturally prepared. Mean age at the initial PAB was 12.2+/-7 years (range, 1.9 to 23 years). Four patients underwent reoperation to tighten the PAB before ASO. Mean interval from PAB to ASO was 1.3+/-0.9 years.

RESULTS

There was no mortality from PAB. Six patients had ASO conversion and 2 died. Recent surgical modifications at the time of ASO were used to prevent neoaortic valve insufficiency and to cryoablate atrial reentry tachycardia. Four patients developed biventricular failure after PAB and had orthotopic cardiac transplantation (OCT) 14+/-10 months after PAB. The other 2 patients are still with PAB: 1 is awaiting ASO conversion and the other has insufficient left ventricular hypertrophy necessary for ASO conversion despite two preparatory PABs.

CONCLUSIONS

A select group of patients with right ventricular failure after atrial baffle operations can undergo staged conversion to ASO with the opportunity for excellent long-term outcome. Surgical modifications at the time of ASO can address the problems of neoaortic insufficiency and persistent atrial arrhythmias. PAB may be a therapeutic endpoint in some patients not responding with adequate left ventricular hypertrophy. Those patients who develop biventricular failure after PAB will require cardiac transplantation.

Long-term results of arterial switch repair of transposition of the great vessels

The arterial switch operation has become the preferred surgical procedure for transposition of the great arteries worldwide. The low operative mortality at "low-risk" institutions has been well documented. The advantages of the arterial switch compared with atrial-level repairs include a lower incidence of arrhythmias and the likelihood of normal systemic ventricular function over the long term. However, the long-term sequelae of this operation must be continually evaluated, including the fate of the supravalvular pulmonary and aortic anastomoses, growth of the aortic root, competency of the neoaortic valve, patency of the coronary arteries, effects on the conduction system, and adequacy of ventricular function. These anatomic results, as well as the neurodevelopmental outcomes of these patients, are summarized in this review. Copyright 1998 by W.B. Saunders Company

Transoesophageal echocardiographic assessment of obstruction to the pulmonary venous pathway in children with Mustard or Senning repair

The morphology and mechanism of obstruction to the pulmonary venous pathway in patients following either Mustard or Senning repair of complete transposition was assessed using transoesophageal echocardiography. Seven patients underwent catheterization and complete transoesophageal study in both transverse and longitudinal planes, followed by balloon dilation of the obstructed venous pathway in five of seven under transoesophageal echocardiography guidance. A complete scan of both systemic and venous pathway was obtained in all patients. Four patients with a Mustard repair were found to have a 'tubular' baffle, with stenosis resulting from a discrete wedge of tissue arising from the atrial free wall in association with fibrous adhesions to the baffle. In the three patients with a Senning repair the intra-atrial baffle showed a characteristic 'peaked' appearance, with stenosis of the venous pathway stenosis related directly to contracture of the patch used to augment the atrial free wall. The mechanism of obstruction appears to be inherent to the different surgical techniques. Indwelling transoesophageal echocardiography provided immediate haemodynamic and morphologic assessment of the efficacy of dilation of the obstructed venous pathway.