Effect of endovascular stenting of right ventricle to pulmonary artery conduit stenosis in infants with hypoplastic left heart syndrome on stage II outcomes

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.

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.

Risk factors for prolonged length of stay after the stage 2 procedure in the single-ventricle reconstruction trial

BACKGROUND

The single-ventricle reconstruction trial randomized patients with single right ventricle lesions to a modified Blalock-Taussig or right ventricle-to-pulmonary artery shunt at the Norwood. This analysis describes outcomes at the stage 2 procedure and factors associated with a longer hospital length of stay (LOS).

METHODS

We examined the association of shunt type with stage 2 hospital outcomes. Cox regression and bootstrapping were used to evaluate risk factors for longer LOS. We also examined characteristics associated with in-hospital death.

RESULTS

There were 393 subjects in the analytic cohort. Median stage 2 procedure hospital LOS (8 days; interquartile range [IQR], 6-14 days), hospital mortality (4.3%), transplantation (0.8%), median ventilator time (2 days; IQR, 1-3 days), median intensive care unit LOS (4 days; IQR, 3-7 days), number of additional cardiac procedures or complications, and serious adverse events did not differ by shunt type. Longer LOS was associated (R(2) = 0.26) with center, longer post-Norwood LOS (hazard ratio [HR], 1.93 per log day; P < .001), nonelective timing of the stage 2 procedure (HR, 1.78; P < .001), and pulmonary artery (PA) stenosis (HR, 1.56; P < .001). By univariate analysis, nonelective stage 2 (65% vs 32%; P = .009), moderate or greater atrioventricular valve (AVV) regurgitation (75% vs 24%; P < .001), and AVV repair (53% vs 9%; P < .001) were among the risk factors associated with in-hospital death.

CONCLUSIONS

Norwood LOS, PA stenoses, and nonelective stage 2 procedure, but not shunt type, are independently associated with longer LOS. Nonelective stage 2 procedure, moderate or greater AVV regurgitation, and need for AVV repair are among the risk factors for death.

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

OBJECTIVES

To determine the incidence of right ventricle-to-pulmonary artery (RV-PA) conduit stenosis after the Norwood I operation in patients with hypoplastic left heart syndrome (HLHS), and to determine whether the treatment strategy of RV-PA conduit stenosis has an influence on interstage and overall survival.

METHODS

Ninety-six patients had a Norwood operation with RV-PA conduit between 2002 and 2011. Details of reoperations/interventions due to conduit obstruction prior to bidirectional superior cavopulmonary anastomosis (BSCPA) were collected.

RESULTS

Overall pre-BSCPA mortality was 17%, early mortality after Norwood, 6%. Early angiography was performed in 34 patients due to desaturation at a median of 8 days after the Norwood operation. Fifteen patients (16%) were diagnosed with RV-PA conduit stenosis that required treatment. The location of the conduit stenosis was significantly different in the patients with non-ringed (proximal) and the patients with ring-enforced conduit (distal), P = 0.004. In 6 patients, a surgical revision of the conduit was performed; 3 of them died prior to BSCPA. Another 6 patients had a stent implantation and 3 were treated with balloon dilatation followed by a BSCPA in the subsequent 2 weeks. All patients who were treated interventionally for RV-PA conduit obstruction had a successful BSCPA. Patients who received a surgical RV-PA conduit revision had a significantly higher interstage (P = 0.044) and overall mortality (P = 0.011) than those who received a stent or balloon dilatation of the stenosis followed by an early BSCPA.

CONCLUSIONS

RV-PA conduit obstruction after Norwood I procedure in patients with HLHS can be safely and effectively treated by stent implantation, balloon dilatation and early BSCPA. Surgical revision of the RV-PA conduit can be reserved for patients in whom an interventional approach fails, and an early BSCPA is not an option.