Femoral vein homograft as Sano shunt results in improved pulmonary artery growth after Norwood operation

Valved Sano conduit improves immediate outcomes following Norwood operation compared with nonvalved Sano conduit

OBJECTIVE

Use of a valved Sano during the Norwood procedure has been reported previously, but its impact on clinical outcomes needs to be further elucidated. We assessed the impact of the valved Sano compared with the nonvalved Sano after the Norwood procedure in patients with hypoplastic left heart syndrome.

METHODS

We retrospectively reviewed 25 consecutive neonates with hypoplastic left heart syndrome who underwent a Norwood procedure with a valved Sano conduit using a femoral venous homograft and 25 consecutive neonates with hypoplastic left heart syndrome who underwent a Norwood procedure with a nonvalved Sano conduit between 2013 and 2022. Primary outcomes were end-organ function postoperatively and ventricular function over time. Secondary outcomes were cardiac events, all-cause mortality, and Sano and pulmonary artery reinterventions at discharge, interstage, and pre-Glenn time points.

RESULTS

Postoperatively, the valved Sano group had significantly lower peak and postoperative day 1 lactate levels (P = .033 and P = .025, respectively), shorter time to diuresis (P = .043), and shorter time to enteral feeds (P = .038). The valved Sano group had significantly fewer pulmonary artery reinterventions until the Glenn operation (n = 1 vs 8; P = .044). The valved Sano group showed significant improvement in ventricular function from the immediate postoperative period to discharge (P < .001). From preoperative to pre-Glenn time points, analysis of ventricular function showed sustained ventricular function within the valved Sano group, but a significant reduction of ventricular function in the nonvalved Sano group (P = .003). Pre-Glenn echocardiograms showed competent conduit valves in two-thirds of the valved Sano group (n = 16; 67%).

CONCLUSIONS

The valved Sano is associated with improved multi-organ recovery postoperatively, better ventricular function recovery, and fewer pulmonary artery reinterventions until the Glenn procedure.

Association Between Venous Homografts and Allosensitization After Norwood Procedure

BACKGROUND

Right ventricle (RV) to pulmonary artery (PA) shunts have become the shunt of choice at many centers for use during the Norwood procedure for single ventricle palliation. Some centers have begun to use cryopreserved femoral or saphenous venous homografts as an alternative to polytetrafluoroethylene (PTFE) for shunt construction. The immunogenicity of these homografts is unknown, and potential allosensitization could have significant implications on transplant candidacy.

METHODS

All patients undergoing Glenn procedure at our center between 2013 and 2020 were screened. Patients who initially underwent Norwood procedure with either PTFE or venous homograft RV-PA shunt and had available pre-Glenn serum were included in the study. The primary outcome of interest was panel reactive antibody (PRA) level at the time of Glenn surgery.

RESULTS

Thirty-six patients met inclusion criteria (N = 28 PTFE, N = 8 homograft). Patients in the homograft group had significantly higher median PRA levels at the time of Glenn surgery (0% [IQR 0-18] PTFE vs 94% [IQR 74-100] homograft, P = .003). There were no other differences between the two groups.

CONCLUSIONS

Despite potential improvements in PA architecture, the use of venous homografts for RV-PA shunt construction at the time of Norwood procedure is associated with significantly elevated PRA level at the time of Glenn surgery. Centers should carefully consider the use of currently available venous homografts given the high percentage of these patients who may require future transplantation.

Experience of a single institution with femoral vein homograft as right ventricle to pulmonary artery conduit in stage 1 Norwood operation

OBJECTIVE

Femoral vein homograft can be used be used as valved right ventricle to pulmonary artery conduit in the Norwood operation. We describe the results of this approach, including pulmonary artery growth and ventricular function.

METHODS

A retrospective chart review of 24 consecutive neonates with hypoplastic left heart syndrome or complex single ventricle undergoing this approach between June 2012 and December 2017 was performed. Conduit valve competency and ventricular function were estimated using transthoracic echocardiogram, and pulmonary artery growth was measured using Nakata's index. Changes in ventricular function pre-Glenn and at latest follow-up were assessed by ordinal logistic regression with a general linear model to account for the correlation within the same patient over time.

RESULTS

Median age at surgery was 4 days, and mean weight was 3 kg. There was no interstage mortality. A total of 21 patients have undergone Glenn operation, and 9 patients have completed the Fontan operation. None of the conduits developed thrombosis. Sixty-three percent of conduits remained competent in the first month, and 33% remained competent after 3 months of operation. Catheter interventions on conduits were necessary in 14 patients. Median Nakata index at pre-Glenn catheterization was 228 mm²/m² (interquartile range, 107-341 mm²/m²). Right ventricular function was preserved in 83% of patients at a median follow-up of 34 (interquartile range, 10-46) months.

CONCLUSIONS

Femoral vein homograft as a right ventricle to pulmonary artery conduit in the Norwood operation is safe and associated with good pulmonary artery growth and preserved ventricular function as assessed by subjective echocardiography. Catheter intervention of the conduit may be necessary.

Impact of a Composite Valved RV-PA Graft After Stage 1 Palliation

BACKGROUND

The use of a valved right ventricular to pulmonary artery shunt (RVPAS) has been reported by some to improve pulmonary artery growth after stage 1 palliation (S1P).

METHODS

We retrospectively reviewed all patients undergoing an S1P with an RVPAS between January 2013 and May 2017, stratified by RVPAS type: a ring-reinforced polytetrafluoroethylene (PTFE) graft or a composite graft that included a distal valved femoral or saphenous vein homograft. We examined the association of RVPAS type on postoperative hemodynamics, time to reintervention, pulmonary artery growth, and survival.

RESULTS

Among 94 infants, 56 (60%) underwent PTFE-only shunt, 24 (25%) underwent femoral vein homograft, and 14 (15%) underwent saphenous vein homograft, and no relevant risk factor differences were found between the groups. Arterial saturation was 2.3% higher (p = 0.014) and serum lactic acid was 1.24 mg/dL lower (p = 0.03) in the femoral vein homograft group than in the PTFE-only group, although venous saturation was similar. By 60 days, 50% of patients with saphenous vein homograft had a reintervention compared with 5% with PTFE graft (p < 0.0001) and 12% with femoral vein homograft (p = 0.2 versus PTFE). At the time of stage 2 palliation, no differences were found in pulmonary artery size or growth over time by either echocardiogram or angiography or in the density of aortopulmonary collaterals or degree of tricuspid regurgitation. The 12-month survival was similar between the groups.

CONCLUSIONS

The use of an interposition femoral vein homograft into the RVPAS may enhance perioperative stability, but it does not substantially improve interstage growth of the pulmonary arteries. Use of saphenous vein homograft is associated with earlier time to reintervention after S1P.