Treatment of right ventricle to pulmonary artery conduit stenosis in infants with hypoplastic left heart syndrome

Catheter Intervention for Flow Regulatory Clips on Palliative Shunts and Conduits in Patients with Congenital Heart Disease

Catheter intervention (CI) for a Blalock-Taussig shunt (BTS) or a ventricle-to-pulmonary artery conduit (VPC) is often required after a palliative surgery for congenital heart disease. Flow regulatory clips help improve interstage mortality; their use necessitates CIs to prevent cyanosis. To study the CI outcomes in patients who underwent palliative surgery with either BTSs or VPCs with flow regulatory clips. This single-center retrospective study evaluated demographic characteristics and interventional outcomes of 49 consecutive pediatric patients who required CI for BTS (BTS group) or VPC (VPC group) between January 2008 and September 2018. Overall, 34 and 18 procedures were performed in the BTS and VPC groups, respectively. Moreover, 19/32 (59.3%) and 12/17 (70.1%) patients from the BTS and VPC groups had flow regulatory clips, respectively. All clips were unclipped successfully; one patient in each group underwent staged unclipping. A higher proportion of "clipped patients" underwent CI due to desaturation [clipped vs. non-clipped: BTS, 10/20 (50.0%) vs. 3/14 (21.4%), p = 0.092; VPC, 9/13 (69.2%) vs. 1/5 (20.0%), p = 0.060]. Most clipped patients successfully progressed to the next stage [BTS, 19/20 (95.0%); VPC, 12/13 (92.3%)]. Severe adverse events (SAEs) were more frequent in the VPC group than in the BTS group [3/13 (23.1%) vs. 0/20 (0%), p = 0.024]. Two patients developed an atrioventricular block (requiring an atropine infusion), while one died due to pulmonary overcirculation. While the indication of CI was cyanosis for a higher proportion of clipped patients, all clips were unclipped successfully. The incidence of CI-related SAEs was higher in the VPC group than in the BTS group.

Use of the novel curved GOKU balloon catheter for acute-angled lesions in palliative surgery for congenital heart disease: comparison with a conventional straight balloon

Obstruction develops commonly at the acute-angled portion of the vessels following palliative surgery, such as systemic-pulmonary shunt (SP shunt), right ventricle-to-pulmonary artery shunt (RV-PA shunt) in the Norwood-Sano procedure for hypoplastic left heart syndrome, and cavopulmonary (Glenn) anastomosis. Although balloon angioplasty is a treatment option, dilation with existing straight balloons is sometimes ineffective and technically complicated because of balloon slippage and target vessel distortion. In this study, we investigated the effectiveness of a curved GOKU balloon catheter for balloon angioplasty in postoperative acute-angled lesions associated with palliative surgery for congenital heart disease. We reviewed patients who underwent balloon angioplasty for angled lesions complicated by SP shunt, RV-PA shunt, or Glenn anastomosis, using the novel curved GOKU or a conventional balloon catheter, such as a Sterling balloon catheter. We evaluated patients' backgrounds, balloon specifications, target lesion anatomical features and angles, and short-term outcomes. We evaluated 45 procedures in 18 patients. A curved GOKU was used in 20 procedures, and a Sterling balloon in 25 procedures. The angulation of the lesions at maximum balloon inflation was significantly smaller using a curved GOKU vs a Sterling balloon [70-120 (mean ± standard deviation, 97 ± 40) degrees vs 110-180 (149 ± 46) degrees, respectively; p < 0.001], while the original angle was similar between the groups. Patients' short-term outcomes with the curved GOKU were excellent, with a significantly better percent increase in minimum lumen diameter of 0-220% (92% ± 66%) vs 0-46% (18% ± 15%) with the Sterling balloon (p < 00.1) and with less frequent balloon slippage. The curved GOKU was more effective in balloon angioplasty for acute-angled lesions compared with a conventional straight balloon, likely because of better conformability to the lesion angle and slip resistance.

Unplanned cardiac reoperations and interventions during long-term follow-up after the Norwood procedure†

OBJECTIVES

Patients with hypoplastic left heart syndrome or related malformations are predominantly treated with a 3-stage palliation. Anatomic or physiologic problems can lead to unplanned additional surgical or catheter interventions during single ventricle palliation. Changes in operative technique may have an impact on the reoperation rate.

METHODS

Between 1997 and 2014, 317 Norwood procedures were performed at our centre. A retrospective single centre investigation was carried out concerning incidence, timing, indication and type of unplanned interstage cardiac reoperations and catheter interventions during follow-up of Norwood patients. Patients were followed from birth until the end of 2015. Cardiac procedures taking place at the time of the bidirectional Glenn or Fontan procedure or heart transplantation were not included.

RESULTS

Sixty-five of the Norwood patients (20.5%) had at least one additional surgical cardiac procedure. Nine patients (2.8%) needed open procedures prior to the Norwood operations, 11.0% had procedures in the interstage I, 3.5% in the interstage II and 9.1% of the Fontan patients had cardiac reoperations afterwards. Main indications for unplanned surgery were insufficient pulmonary perfusion and tricuspid regurgitation. Eighty-one patients (25.6%) had at least one interstage catheter intervention during follow-up mainly addressing stenosis of the pulmonary arteries, aortic arch stenosis or aortopulmonary collaterals.

CONCLUSIONS

The number of unplanned reoperations and interventions during staged palliation is remarkably high showing surgical peaks in the interstage I and after the Fontan procedure and an interventional peak in the interstage II. Thorough early information of the parents about possibly anticipated additional procedures is necessary.

Norwood Procedure for Palliation of Hypoplastic Left Heart Syndrome: Right Ventricle to Pulmonary Artery Conduit vs Modified Blalock-Taussig Shunt

Patients with hypoplastic left heart syndrome undergo a series of operations to separate the pulmonary and systemic circulations. The first of at least 3 operations occurs in the newborn period, with a stage I palliation. The goal of stage I palliation is to provide pulmonary blood flow and create an unobstructed systemic outflow tract. Advances in surgical techniques and intraoperative and postoperative care have helped decrease morbidity and mortality for patients with hypoplastic left heart syndrome who have the stage I Norwood operation, but the patients continue to be at increased risk for hemodynamic collapse and adverse outcomes. This article discusses risk factors, surgical approach, postoperative nursing and medical management strategies, differences between and outcomes for the Norwood operation with the right ventricle to pulmonary artery conduit and the Norwood operation with a modified Blalock-Taussig shunt.

Interstage evaluation of homograft-valved right ventricle to pulmonary artery conduits for palliation of hypoplastic left heart syndrome

OBJECTIVE

Palliation of hypoplastic left heart syndrome with a standard nonvalved right ventricle to pulmonary artery conduit results in an inefficient circulation in part due to diastolic regurgitation. A composite right ventricle pulmonary artery conduit with a homograft valve has a hypothetical advantage of reducing regurgitation, but may differ in the propensity for stenosis because of valve remodeling.

METHODS

This retrospective cohort study included 130 patients with hypoplastic left heart syndrome who underwent a modified stage 1 procedure with a right ventricle to pulmonary artery conduit from 2002 to 2015. A composite valved conduit (cryopreserved homograft valve anastomosed to a polytetrafluoroethylene tube) was placed in 100 patients (47 aortic, 32 pulmonary, 13 femoral/saphenous vein, 8 unknown), and a nonvalved conduit was used in 30 patients. Echocardiographic functional parameters were evaluated before and after stage 1 palliation and before the bidirectional Glenn procedure, and interstage interventions were assessed.

RESULTS

On competing risk analysis, survival over time was better in the valved conduit group (P = .040), but this difference was no longer significant after adjustment for surgical era. There was no significant difference between groups in the cumulative incidence of bidirectional Glenn completion (P = .15). Patients with a valved conduit underwent more interventions for conduit obstruction in the interstage period, but this difference did not reach significance (P = .16). There were no differences between groups in echocardiographic parameters of right ventricle function at baseline or pre-Glenn.

CONCLUSIONS

In this cohort of patients with hypoplastic left heart syndrome, inclusion of a valved right ventricle to pulmonary artery conduit was not associated with any difference in survival on adjusted analysis and did not confer an identifiable benefit on right ventricle function.

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 ± 4.1 vs 4.8 ± 3.8 mmHg in controls, P < 0.001) and Nakata index (213 ± 76 vs 134 ± 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.