Outcomes of Supra-annular Mechanical Atrioventricular Valve Replacement with Polytetrafluoroethylene Graft in Infants and Children.

Despite improvements in valve repair techniques, conditions in which infants and children need for mechanical valve replacement (MVR) are still present. We analyzed supra-annular MVR outcomes in infants and children with small annulus and compared them with conventional annular MVR outcomes. Data were collected retrospectively from medical records of infants and children (weighing < 20 kg) who underwent atrioventricular valve replacement with mechanical valve in Seoul National University Children's Hospital between December 1984 and January 2019. We identified 8 patients (median age 20 months, median weight 10.2 kg) who underwent supra-annular MVR with polytetrafluoroethylene graft (supra-annular group). The patients were diagnosed with congenital mitral valve malformation (5 patients), complete atrioventricular septal defect (2 patients), and functional single ventricle (1 patient). The implanted mechanical valve size ranged from 16 to 23 mm. Thirty-three patients (median age 40 months, median weight 13 kg) underwent conventional annular MVR (annular group). The survival rate was not significantly different between the supra-annular and annular groups (75.0 vs 78.8%, P = 0.816). In patients with biventricular repair (7 patients with supra-annular MVR and 28 patients with annular MVR), mechanical valve-to-mitral valve annulus size ratio was higher in the supra-annular group than in the annular group (1.24 ± 0.30 vs 0.96 ± 0.22, P = 0.035). No coronary complication or heart block were observed in the supra-annular group. Supra-annular MVR with polytetrafluoroethylene graft may be a feasible surgical option in children with a small annulus when valve repair is unsuccessful.

Simplified Tricuspid Polytetrafluoroethylene Valved Conduit: Midterm Results of Multicenter Study.

BACKGROUND: Conduit survival without significant dysfunction is important when selecting the right ventricular outflow tract conduit. We made an expanded polytetrafluoroethylene tricuspid valved conduit using a simplified technique. We aimed to investigate the midterm functional results and longevity of this conduit. METHODS: Between November 2008 and December 2016, four hospitals in Korea implanted 145 valved conduits. We retrospectively analyzed their functional results and longevity. RESULTS: The patients' median age at operation was 36.6 months; the median body weight was 11.3 kg. The mean follow-up duration was 32.3 ± 24.5 months. There were four inhospital deaths and three late deaths, but there were no conduit-related deaths. The mean peak systolic pressure gradient across the conduit was 14.7 ± 8.3 mm Hg and 31.6 ± 17.7 mm Hg at discharge and last follow-up, respectively. Six patients (4.4%) had moderate or more conduit valve regurgitation at last follow-up. Conduit dysfunction was observed in 30 patients (21.9%), mainly caused by increased pressure gradient (24 of 30, 80%). Freedom from conduit dysfunction was 88.1% and 58.5% at 3 and 5 years, respectively. Lower freedom from conduit dysfunction was observed in small conduits. Eleven patients (7.8%) underwent conduit explantation, and freedom from explantation was 94.8% and 81.7% at 3 and 5 years, respectively. The main cause of explantation was conduit stenosis. Small conduits tended to have lower freedom from explantation. CONCLUSIONS: Functional results and longevity of our expanded polytetrafluoroethylene tricuspid valved conduit are acceptable. Although our conduits tend to have increasing pressure gradient over time, especially in small conduits, they have low incidence of moderate or more regurgitation.

Dor procedure for pulmonary atresia with intact ventricular septum in an infant.

Pulmonary atresia with intact ventricular septum and right ventricle-dependent coronary circulation confers a high risk for myocardial infarction and complications of ischaemia, including left ventricle aneurysms. We describe an infant with pulmonary atresia with intact ventricular septum and right ventricle-dependent coronary circulation and a left ventricle apical aneurysm who successfully underwent the Dor procedure and a subsequent Fontan operation. Surgery for postinfarction left ventricle aneurysm can be considered in infants.

Outcomes after extracardiac Fontan procedure with a 16-mm polytetrafluoroethylene conduit.

OBJECTIVES: We evaluated the outcomes of patients who underwent extracardiac Fontan circulation procedures (ECFP) and received 16-mm polytetrafluoroethylene conduits. METHODS: From June 1997 to May 2015, among the 408 patients who underwent ECFP, 66 patients (Group S) also received 16-mm polytetrafluoroethylene conduits. To compare this patient cohort with similarly sized patients who received larger conduits, a matched cohort (66 patients, Group L) was selected according to age and body weight. RESULTS: The mean age, body weight and Nakata index at ECFP in Groups S and L were 2.9 ± 1.2 and 3.1 ± 1.2 years (P = 0.243), 13.0 ± 2.4 and 13.0 ± 2.3 kg (P = 0.101), 175.3 ± 59.0 and 236.1 ± 75.1 mm2/m2 (P = 0.005), respectively. The mean follow-up periods for Groups S and L were 7.8 ± 6.0 and 9.1 ± 4.9 years (P = 0.150), respectively. The conduit size of Group L was 19.2 ± 1.4 mm (P < 0.001). There was no significant difference in mortality between the groups (P = 0.109). The freedom from reoperation was 94.0 ± 3.4% in Group S and 79.3 ± 5.7% in Group L after 10 years (P = 0.070). Late-occurring morbidities included protein-losing enteropathy (2 in Group S, 4 in Group L; P = 0.491) and thromboembolism (0 in Group S, 4 in Group L; P = 0.206). There was a significant difference in conduit-related events between the groups (1 in Group S, 5 in Group L; P = 0.031). In a paired cohort from the 2 groups including patients who were followed-up for more than 10 years (15 patients from each group), the body mass index was 51.0 ± 33.2% in Group S and 30.3 ± 34.2% in Group L. The decreases in the conduit cross-sectional areas for the paired patients in Group S (n = 20) and Group L (n = 20) were 14.9 ± 19.7% and 24.5 ± 15.5% (P = 0.076), respectively. Coarse liver parenchyma was detected in 9 of 23 (39.1%) patients from Group S and in 7 of 18 (38.8%) patients from Group L upon ultrasonography. CONCLUSIONS: The 16-mm polytetrafluoroethylene conduit for ECFP showed acceptable outcomes and good haemodynamic status in small-sized patients. According to our results, small patients do not require large conduits to accommodate their growth potential.

Midterm follow-up of the status of Gore-Tex graft after extracardiac conduit Fontan procedure.

OBJECTIVE: Extracardiac conduit Fontan procedure has some theoretical advantages over other types of Fontan procedures, such as optimized flow dynamics, a lower frequency of arrhythmias, and technical ease of procedure. However, lack of growth potential and thrombogenicity of the artificial conduit is the main concern and can possibly lead to reoperation for the conduit stenosis. In this study, we investigated the change and the status of the Gore-Tex graft used in extracardiac conduit Fontan procedure. METHODS: Between 1996 and 2005, 154 patients underwent extracardiac conduit Fontan procedure using Gore-Tex graft. Among these, 46 patients underwent cardiac catheterization during follow-up period. We measured the internal diameter of the conduit and inferior vena cava angiographically. RESULTS: Mean follow-up duration was 36.1+/-19.7 months. The conduit diameter used was 16 mm in 10 patients, 18 mm in 16, 20 mm in 14, 22 mm in 4, and 24 mm in 2 patients. The mean conduit-to-inferior vena cava cross-sectional area ratio was 1.25+/-0.33. According to the conduit size used, this ratio was 1.03+/-0.17 for 16 mm conduits, 1.33+/-0.37 for 18 mm, 1.33+/-0.36 for 20 mm, 1.28+/-0.26 for 22 mm, and 1.05+/-0.06 for 24 mm conduits (p<0.05, 16 mm vs 18 mm and 20 mm). The mean percent decrease of the conduit cross-sectional area was 14.3+/-8.5%, and this did not differ significantly according to the conduit size (p=0.82). Follow-up duration and the percent decrease of the conduit cross-sectional area did not show significant correlation (r=0.22, p=0.14). There was no reoperation due to conduit stenosis. CONCLUSIONS: During midterm follow-up of about 3 years, the conduit cross-sectional area decreased by 14%, and this did not differ according to the conduit size used. The extent of decrease of the conduit cross-sectional area remained stable irrespective of the follow-up duration. Sixteen millimeters conduit showed no evidence of clinically significant stenosis, but careful follow-up is warranted because of the possible conduit stenosis relative to the patients' somatic growth.

Surgical strategy for pulmonary coarctation in the univentricular heart.

OBJECTIVE: The placement of a modified Blalock-Taussig shunt in patients suffering from pulmonary coarctation can result in the aggravation of uneven pulmonary blood flow. This may subsequently obviate the possibility of future performance of the Fontan procedure. The objective of this study was to evaluate mid-term results in patients with pulmonary coarctation who had undergone the placement of a modified Blalock-Taussig shunt, coupled with a pulmonary artery angioplasty. METHODS: We retrospectively reviewed the records of 13 patients who had undergone the placement of a modified Blalock-Taussig shunt, coupled with concomitant pulmonary angioplasty, between September 1998 and August 2002. All patients received follow-up angiographic evaluations. RESULTS: On the ipsilateral side of the modified Blalock-Taussig shunt, we observed a significant increase in the pulmonary artery index during a mean follow-up period of 11+/-5 months (preoperative 82+/-37 mm2/m2, follow-up 129+/-57, p=0.03). On the contralateral side, we also observed a significant increase in the pulmonary artery index (preoperative 90+/-56 mm2/m2, follow-up 137+/-56, p=0.047). There was one late death. During the follow-up period (mean 23+/-18 months), 10 patients received either a bidirectional or total cavopulmonary shunt and five of these patients underwent extracardiac Fontan operations. CONCLUSIONS: Our study demonstrated that the placement of a modified Blalock-Taussig shunt, with concomitant pulmonary artery angioplasty, constitutes a good initial surgical strategy in cases of univentricular heart with pulmonary coarctation.