Long-term results after extracardiac valved conduits implanted for complex congenital heart disease

Bovine Valved Xenograft in Pulmonary Position: Medium-Term Follow-Up With Excellent Hemodynamics and Freedom From Calcification

BACKGROUND

This study was designed to evaluate the outcome of Contegra xenograft valved conduit (Contegra, Medtronic Inc, Minneapolis, MN).

METHODS

From April 1999 to December 2003, 67 patients with a mean age of 16.1 +/-15.0 years (2 months to 53 years) and a mean weight of 39.7 +/- 27.1 kg (4 to 95 kg) were discharged after implantation of a Contegra conduit. The diagnosis contained the following: pulmonary valve replacement during Ross operation (n = 27), pulmonary valve regurgitation (n = 9), tetralogy of Fallot (n = 7), pulmonary atresia with ventricular septal defect (n = 7), double outlet right ventricle (n = 7), truncus arteriosus (n = 5), Taussig-Bing (n = 2), obstructed conduit (n = 2), and double discordance (n = 1). Conduit size was 14 mm in 2, 16 mm in 7, 18 mm in 12, 20 mm in 13, and 22 mm in 33 patients. Mean cardiopulmonary bypass was 155 +/- 48 min (65 to 337 min) and mean aortic cross clamping was 69 +/- 38 min (0 to 146 min). All patients underwent echocardiography, 23 of 67 (34%) patients had cardiac catheterization, and 23 of 67 (34%) patients had electrocardiograph-gated multislice computer tomography.

RESULTS

In a mean follow-up of 26.4 months (1 to 56 months) there was one late death (1 of 67 patients; 1.5% mortality) unrelated to the conduit. Five patients underwent reoperation; four were nonconduit-related and one was to replace a twisted conduit. Five patients underwent interventional cardiology; three were nonconduit-related and two were to stent a twisted or stenotic conduit. Echocardiography showed absent valve regurgitation in 30 of 67 (45%) patients, trivial in 21 of 67 (31%) patients, mild in 16 of 67 (24%) patients. The transconduit pressure gradient remained stable during follow-up, with peak pressure gradient 17 +/- 11 mm Hg and mean gradient 8 +/- 6 mm Hg. Internal diameters corresponded to 110% +/- 20% of the implanted diameter at level of proximal anastomosis, 112% +/- 18% at valve level, and 110% +/- 14% at distal anastomosis. Calcifications were not found, with the exception of a minimal (2.3 mm) parietal calcification.

CONCLUSIONS

The Contegra valved conduit provided excellent morphology and hemodynamics, and freedom from calcification in a medium-term follow-up.

Conversion of the hemi-Fontan procedure to fenestrated total extracardiac cavopulmonary bypass

BACKGROUND

Arrhythmias occur frequently after Fontan operations, and are related in part to high atrial pressure, wall distention, and scarring caused by extensive suture lines. These arrhythmic factors may be avoided by an extracardiac total cavopulmonary anastomosis. We have embarked on a program of conversion of the hemi-Fontan operation to a fenestrated extracardiac Fontan procedure with a relatively simple operation.

METHODS

In a 4-month period ending in December 1994, 4 consecutive patients underwent this procedure. The inferior vena cava was divided and the cardiac end was oversewn. A large (20 to 25 mm) ascending aortic homograft, from which the inlet portion and valve had previously been excised, was interposed between the divided distal end of the inferior vena cava and the hood of the superior cavopulmonary anastomosis. A 4-mm fenestration with a pursestring snare mechanism was placed within the cavoatrial patch that had been implanted at the time of the hemi-Fontan procedure.

RESULTS

There were no deaths, and the average length of stay was 12 +/- 4 days (range, 8 to 18 days). In early follow-up, there have been no atrial arrhythmias, and three of the four fenestrations have been documented to be patent.

CONCLUSIONS

An extracardiac fenestrated Fontan procedure can safely and successfully be performed after a hemi-Fontan operation, and may have both hemodynamic and arrhythmic benefits.

Diagnosis of stenosis in a pulmonary valve-conduit using an angioplasty guide and probing catheter

A 42-year-old man who had undergone previous Blalock-Taussig anastomoses and placement of a homograft aortic valve-root conduit for tetralogy of Fallot presented with dyspnea at rest. Previous catheterization had shown homograft stenosis at the level of the pulmonic valve. Repeat catheterization necessitated the use of angioplasty guide and probing catheters to cross the stenosis, and pullback documented stenoses both across the homografted valve and within the homograft aortic root-native pulmonary artery conduit.