Modified Shumacker repair of transposition of the great arteries

Modification of the Senning procedure in the double-switch operation: The triangular double-door technique

We developed a modified Senning procedure in the double-switch operation for the patients with congenitally corrected transposition of the great arteries (ccTGA). In our technique, the right atrial (RA) free wall is not used as a baffle for draining systemic venous blood to the left atrium. Instead, a patch material is used for the baffling. A wide communication between the pulmonary venous chamber and RA is created by making the triangular double door with the RA-free wall, and the window is closed with in situ pericardial flap. We have successfully adopted this technique in our recent two consecutive ccTGA patients.

Long-term results of anatomic correction for congenitally corrected transposition of the great arteries: A 19-year experience

OBJECTIVE

The surgical indication, timing, strategy, and surgical technique for anatomic correction of congenitally corrected transposition of the great arteries are challenging. We evaluated the long-term results at The Royal Children's Hospital Melbourne.

METHODS

Review of 32 successive anatomic corrections between 1996 and 2015.

RESULTS

Twenty-one double-switch (66%), 6 Senning/Bex-Nikaidoh (19%), and 5 Senning/Rastelli (16%) procedures were performed (median age, 1.9 years). Median follow-up was 5.4 years with 4 deaths and 1 heart transplant. Cumulative incidence of late reoperation was 8%, 29%, and 59% at 1, 5, and 10 years, respectively. Twenty-six patients had full follow-up with native hearts. Nineteen had normal left ventricle (LV) function. Late LV dysfunction, mostly mild, was not related to needing a pacemaker (P = .4) or a pulmonary artery band (PAB) (P = .08). Previous PAB was linked to the need for aortic valve surgery or neoaortic regurgitation moderate or greater (P = .03). Six required Senning revision. The introduction of the Shumacker modification of the Senning has generated stable pulmonary venous pathways. Six patients developed postoperative iatrogenic atrioventricular block dependent on a permanent pacemaker.

CONCLUSIONS

Anatomic correction is a surgical challenge. It provides excellent functional outcomes in survivors with a significant need for reoperation and a definite risk of death or transplantation. Normal LV function should be expected in most patients. LV dysfunction was not linked to PAB or pacemaker requirement but surgery without LV training had better long-term LV function. The Shumacker modification provided stable venous pathways. Iatrogenic atrioventricular block remains a challenge.

Pedicled pericardial flap for pulmonary artery in adult dogs

OBJECTIVE

Stenosis of extracardiac conduit after reconstruction of right ventricle outflow tract is a serious problem, and the purpose of this study was to identify the suitability of broadly pedicled autologous pericardial flap for the reconstruction of pulmonary artery trunk in adult dogs.

METHODS

Eight mongrel dogs had replacement of a pulmonary artery trunk with extracardiac conduit, in which prosthetic vascular graft formed the posterior wall and pedicled (group P, n = 5) or free (group F, n = 3) autologous pericardium created the anterior wall. Six months after the operation, pressure gradient across the conduit were measured and put to death for pathological examinations.

RESULTS

Pressure gradient across the conduit in groups F and P was 16.0 +/- 16.8 mmHg and 1.4 +/- 1.7 mmHg respectively. In the microscopic examination, flaps of group P had neo-intimal cells in the innermost layer, abundant cellular component with elastic fiber was seen within the middle layer, and collagen tissue within the outer layer. Conversely, the presence of calcification was shown within collagen fiber layer of all patches in group F. Sparse cellular component and the absence of neo-intimal cells were also observed in group F.

CONCLUSIONS

Broadly pedicled pericardial flap is more conceivable to prevent the development of conduit stenosis after right ventricle outflow tract reconstruction, if compared with free pericardial patches.

Pedicled pericardium for repair of right ventricular outflow tract and pulmonary arterial stenoses in tetralogy of Fallot: a six-year experience

From June 1988 through June 1994, 20 children with symptomatic tetralogy of Fallot, associated with hypoplastic or stenotic pulmonary arteries in 19 cases, were operated on in our institution. Mean age at operation was 49.5 +/- 43 months (ranging from 10 months to 12.5 years). Mean weight was 13.5 +/- 6.5 kg (range 6.2 to 30 kg) and mean body surface area was 0.6 +/- 0.2 m2. Mean preoperative hematocrit value was 47.6% +/- 11.1%, and mean preoperative arterial oxygen saturation ratio was 75.7 +/- 9.5. Six patients (30%) had prior systemic-pulmonary arterial shunts. Pulmonary arterial stenoses were congenital or iatrogenic (or both) and were located principally on the left pulmonary artery (63%), on the pulmonary bifurcation (15%), or separately on the left and right pulmonary arteries (21%). In all children the pulmonary arterial tree was repaired with the patient's own pedicled pericardium. Mean follow-up is 36 +/- 25.2 months (range 1 to 71 months). Hospital mortality rate was 0%. There was one late death, and two children were lost to long-term follow-up. No child required reoperation. Seventeen children returned for evaluation, consisting of physical examination, electrocardiogram, chest roentgenogram, and Doppler echocardiogram, and 11 underwent late catheterization or magnetic resonance imaging of the chest to evaluate the pulmonary arterial repair. All children were in New York Heart Association class I or II. Right ventricular function was normal by echocardiography in 100% with a mean right ventricular systolic pressure of 39.37 +/- 8.4 mm Hg. Mild to moderate pulmonary regurgitation was present in the majority of patients. The results of pulmonary arterial repair were good in 100%. There was no residual stenosis, and we observed uniform enlargement of the repaired pulmonary arteries over a 5-month to 6-year follow-up period. These results are of particular interest inasmuch as other materials previously used for repair of pulmonary arteries do not grow and may even shrink, resulting in residual stenosis.

Transesophageal study of recurrent atrial tachycardia after atrial baffle procedures for complete transposition of the great arteries

Transesophageal study was used for diagnosis and treatment of 51 episodes of tachycardia in 13 patients with complete transposition of the great arteries who had undergone atrial baffle procedure. At the time of atrial baffle procedure, patients were 6 to 36 months old (mean 23). Tachycardia (1 to 17 episodes per patient) first occurred 1 to 23 days (4 patients) or 1.8 to 12 years (9 patients) after atrial baffle. Transesophageal study was performed using a bipolar silicone rubber-coated catheter. Tachycardia conversion was accomplished with stimulation bursts using 4 to 10 stimuli 9.9 ms in duration at 20 to 28 mA and an interstimulus interval of 50 to 100 ms less than the atrial cycle length. All tachycardia episodes had regular atrial cycle lengths ranging from 200 to 350 ms. In 12 patients, second-degree atrioventricular (AV) block was observed during tachycardia, suggesting primary atrial tachycardia. However, in 1 patient, occurrence of AV block always resulted in tachycardia termination, suggesting the presence of AV reentrant tachycardia. Transesophageal stimulation converted 48 of 51 tachycardia episodes to sinus/junctional rhythm. Ten tachycardia episodes in 6 patients were transiently converted to atrial fibrillation lasting 3 seconds to 28 minutes before spontaneous conversion to sinus junctional rhythm. Conversion attempts were unsuccessful on 3 occasions. Acceleration of ventricular rate after stimulation necessitated DC cardioversion on 1 occasion. Conversion was not achieved in 2 tachycardia episodes using stimuli less than 10 mA. Transesophageal study is a safe and effective minimally invasive technique for diagnosis and treatment of tachycardia in infants and children who have had atrial baffle for transposition of the great arteries.