Results of Less Than 5-mm Right Ventricle-Pulmonary Artery Conduits in Single Ventricle Palliation.

BACKGROUND: Our programmatic approach to single ventricle (SV) neonatal palliation has evolved to using smaller-size right ventricle to pulmonary artery (RV-PA) conduits for pulmonary blood flow. Therefore, we sought to compare the early outcomes of less than 5-mm versus 5-mm RV-PA conduits in SV patients undergoing neonatal palliation. METHODS: We performed a retrospective review of SV patients who had neonatal palliation with either a less than 5-mm or 5-mm RV-PA connection, constructed using a waterproof, breathable fabric membrane graft (Gore-Tex, Flagstaff, AZ). Data before, during, and after surgery were analyzed using SPSS software. RESULTS: A total of 26 patients in group 1 (n = 11; <5 mm) and group 2 (n = 15; 5 mm) were operated on, with a mean follow-up of 13 months. Statistical differences (P ≤ .05) were noted with renal near-infrared spectroscopy (mean, 56 versus 44), and oxygen saturation at discharge (mean, 80% versus 85%) in groups 1 and 2, respectively. We found no significant difference in patient weight, peak lactate, cerebral near-infrared spectroscopy, length of intubation, length of hospitalization, or need for RV-PA conduit intervention after stage 1 along with age, branch PA sizes, or need for PA plasty at bidirectional Glenn between groups. CONCLUSIONS: Our early results of less than 5-mm conduits support further exploration into the tailoring of the RV-PA conduit size for each patient. A smaller-diameter conduit may improve systemic cardiac output and net oxygen delivery. Larger patient cohorts and longer follow-up with assessment of pulmonary artery growth are warranted to guide clinical practice.

Initial shunt type at the Norwood operation impacts myocardial function in hypoplastic left heart syndrome.

OBJECTIVES: We investigated the impact of initial shunt type, a Blalock-Taussig (BT) shunt versus a right ventricle to pulmonary artery conduit (RV-PA) on myocardial function at different stages of surgical palliation in patients with hypoplastic left heart syndrome (HLHS). METHODS: A population-based cohort of 63 Finnish children with HLHS (BT n = 23, RV-PA n = 40) born between 2003 and 2010 were studied retrospectively by echocardiography prior to Stages 1, 2 and 3 palliation and 0.5-3 years after Stage 3. For comparison of systolic myocardial function, we evaluated the RV fractional area change (FAC), strain, strain rate and mechanical synchrony from the apical 4-chamber view by velocity vector imaging. RESULTS: There were no intergroup differences in demographics during the study period. At baseline, no intergroup differences were detected in RV systolic myocardial function. Before Stage 2, RV FAC was higher ( P = 0.03) in the RV-PA conduit group. At Stage 3, an increase in all systolic myocardial functional parameters was observed in the BT shunt group. After Stage 3, the BT shunt group had better RV systolic function. In multiple regression analysis, the shunt type and the stage of palliation had an impact on myocardial function. CONCLUSIONS: Although patients with HLHS initially palliated with a BT shunt demonstrate lower RV FAC after Stage I, RV FAC improves after Stage 2 with better systolic performance after Stage 3 compared with those initially palliated with an RV-PA conduit.

Ring-reinforced Sano right ventricular to pulmonary artery conduit at Norwood stage I.

Reinterventions for proximal conduit obstruction or on the pulmonary arteries are frequent after Sano-modified stage I Norwood palliation of hypoplastic left heart syndrome. We report our experience with a modified Sano stage I, in which the right ventricle-to-pulmonary artery (PA) conduit used is reinforced by external rings to avoid collapse, and the conduit is inserted into the right ventricle through a limited ventriculotomy and 'dunked' into the ventricular cavity. In our experience, this modification was associated with fewer reinterventions or complications with the proximal anastomosis (P = 0.046 and 0.004), improved PA pulse pressure (9.1 ±â€…4.1 vs 4.8 ±â€…3.8 mmHg in controls, P < 0.001) and Nakata index (213 ±â€…76 vs 134 ±â€…68 mm(2)/m(2) in controls, P < 0.0001), although overall survival to a median of 20 months was not significantly different from controls. Right ventricular function at stage II-bidirectional Glen was marginally better in patients with the modified Sano conduit, however not to a significant level. Further evaluation of late ventricular function is currently ongoing.

A reinforced right-ventricle-to-pulmonary-artery conduit for the stage-1 Norwood procedure improves pulmonary artery growth.

OBJECTIVE: To compare early postoperative outcomes, angiographic, and intervention findings and 1-year survival between 2 groups of infant patients: those receiving a standard right-ventricle-to-pulmonary-artery (RV-PA) conduit versus a ring-reinforced RV-PA conduit, in undergoing Norwood stage-1 surgery for hypoplastic left heart syndrome (HLHS). The technique of using such a ring-reinforced graft, placed through a limited ventriculotomy, has theoretic advantages in preserving right ventricular function, compared with the standard technique of RV-PA conduit creation. METHODS: This retrospective cohort study was performed between July 2006 and July 2013. A total of 87 patients with HLHS underwent Norwood stage-1 surgery during this period; 48 received a standard nonreinforced RV-PA conduit; 39 received a ring-reinforced conduit. Primary and secondary outcomes were survival and need for cardiac reintervention up to age 12 months. RESULTS: No difference was found in transplant-free survival by age 12 months (87% ring-reinforced vs 73% nonreinforced, P = .12). The group with the nonreinforced, versus ring-reinforced, grafts had more interventions in the first year (69% vs 35%, respectively; P < .01). Before stage 2, the pulmonary artery pulse pressure was greater in the group with ring-reinforced grafts (9.1 ± 4.1 vs 4.8 ± 3.1 mm Hg, P < .001), with no difference in mean pressure (15.2 ± 3.32 vs 14.3 ± 3.48 mm Hg, P = .27). The corrected pulmonary artery index (Nakata) was greater in the group with ring-reinforced grafts (213 ± 76 vs 134 ± 68 mm(2)/m(2), P < .0001). CONCLUSIONS: A ring-reinforced conduit is associated with reduced intervention, as well as higher pulse pressures and improved pulmonary artery growth, in infants undergoing stage-1 palliation for HLHS.

Ring-reinforced Sano conduit at Norwood stage I reduces proximal conduit obstruction.

BACKGROUND: Reinterventions for proximal conduit obstruction or on the pulmonary arteries are frequent after the Sano-modified stage I Norwood palliation of hypoplastic left heart syndrome. We report our initial experience with a modified Sano technique using a ring-reinforced graft inserted transmurally through the right ventricle with a limited ventriculotomy. METHODS: All patients who underwent the Sano-modified stage I Norwood procedure using a modified "dunked" technique from September 2010 to September 2012 at our institution were reviewed. An historical control group consisted of patients undergoing the traditional Sano right ventricle-to-pulmonary artery conduit anastomosed to the epicardium. The primary outcome measures included death, reintervention on the Sano and pulmonary arteries, and ventricular function. RESULTS: The study included 29 patients. No patients required intervention on the Sano conduit, pulmonary arteries, or aortic arch before discharge after the stage I procedure. During a median follow-up of 20 months (range, 26 days to 3.3 years), survival was estimated at 96.6% ± 3.4% at 1 month and 86.2% ± 6.4% at the latest follow-up. One patient underwent heart transplantation. No interstage intervention was required on the proximal or distal Sano conduit. Intervention was required on the midportion of the conduit in 1 patient and on the pulmonary arteries in 3 patients. At the time of the bidirectional Glenn anastomosis, freedom from conduit and pulmonary artery intervention was estimated at 92.3% ± 7.4% and 90.1% ± 8.7%, respectively, and global right ventricular dysfunction was mild or less in 84% (16 of 19) of patients. CONCLUSIONS: The ring-reinforced right ventricle-to-pulmonary artery Sano conduit transmurally inserted into the right ventricle provides acceptable results, with a low incidence of interstage reinterventions in patients undergoing stage I palliation.

Modified Norwood procedure with a handmade down-sizing valved right ventricle-to-pulmonary artery conduit.

First-stage palliation of hypoplastic left heart syndrome has been revolutionized by the recent introduction of a right ventricle-to-pulmonary artery (RV-PA) conduit as an alternative to a systemic-to-pulmonary shunt. However, most conduits are unvalved, and the use of valved xenografts was abandoned during the early era of this operation. We performed a successful modified Norwood operation in a 2-month-old infant with aortic atresia and ventricular and atrial septal defects using a hand-made down-sizing valved graft as an RV-PA conduit. The postoperative course was uneventful with well-balanced pulmonary and arterial perfusion. We believe that minimization of the regurgitant volume from an unvalved prosthetic conduit by utilizing this modification might be of benefit in this particular group of patients.