Transcatheter interventions post Norwood/Sano procedures: single-centre experience.

Invited commentary

Apples to oranges: Making sense of hybrid palliation for hypoplastic left heart syndrome

Introduction: Central shunts (aorta) and Sano shunts (right ventricle) connected to the pulmonary arteries (PAs) are vital operations for infants with complex heart defects. However, they can become thrombosed. Hypothesis: At sites of prominent angulation, flow augments wall shear stress (WSS), a determinate of platelet-mediated thrombosis. Methods: We employed a patient-based computational model (Fluent) of pulsatile flow (viscosity 5 cPa-s), using a finite volume method and cardiac catheterization data, and geometric simulations (Autodesk Inventor), using angiography, to study flow behavior and WSS. Two central (4.0 and 3.5 mm) and Sano (5 and 6 mm) shunts were assessed. At the inlet to the central and Sano shunts, ascending aorta (AAo, 87/40 and 93/35 mmHg) and right ventricle (RV, 99/10 and 84/10 mmHg) pressures were used, respectively. At the outlets, measured PA pressures were used. Results: For central shunts, Fig 1, WSS reached 245 Pa and 123 Pa, peak systole. For Sano shunts, Fig 2, WSS attained 203 Pa and 133 Pa, peak systole. At sites of angulation, we identified flow vortices augmenting WSS (>100 Pa), and downstream regions of flow stagnation and recirculation, which are conducive to platelet aggregation and thrombus formation. Shunt burden, assessed by averaging WSS over the luminal surface of the shunts and the cardiac cycle, was 73.0 Pa and 67.2 Pa for central shunts, and 34.9 Pa and 19.6 Pa for Sano shunts. Conclusions: Our results indicate central shunts present a higher risk for thrombosis than Sano shunts. Importantly, WSS induced, platelet-mediated thrombosis is insensitive to aspirin, as the process does not involve the cyclooxygenase pathway.

ENWEndNote BIBJabRef, Mendeley RISPapers, Reference Manager, RefWorks, Zotero AMA Moszura T, Dryżek P, Bobkowski W, et al. Original paperPercutaneous interventions in patients with hypoplastic left heart syndrome after stage first Norwood operation. Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej. 2011;7(4):277-284. doi:10.5114/pwki.2011.25785. APA Moszura, T., Dryżek, P., Bobkowski, W., Góreczny, S., Mazurek-Kula, A., & Moll, J. et al. (2011). Original paperPercutaneous interventions in patients with hypoplastic left heart syndrome after stage first Norwood operation. Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej, 7(4), 277-284. https://doi.org/10.5114/pwki.2011.25785 Chicago Moszura, Tomasz, Paweł Dryżek, Waldemar Bobkowski, Sebastian Góreczny, Anna Mazurek-Kula, Jadwiga A. Moll, and Jacek J. Moll et al. 2011. "Original paperPercutaneous interventions in patients with hypoplastic left heart syndrome after stage first Norwood operation". Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej 7 (4): 277-284. doi:10.5114/pwki.2011.25785. Harvard Moszura, T., Dryżek, P., Bobkowski, W., Góreczny, S., Mazurek-Kula, A., Moll, J., Moll, J., and Sysa, A. (2011). Original paperPercutaneous interventions in patients with hypoplastic left heart syndrome after stage first Norwood operation. Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej, 7(4), pp.277-284. https://doi.org/10.5114/pwki.2011.25785 MLA Moszura, Tomasz et al. "Original paperPercutaneous interventions in patients with hypoplastic left heart syndrome after stage first Norwood operation." Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej, vol. 7, no. 4, 2011, pp. 277-284. doi:10.5114/pwki.2011.25785. Vancouver Moszura T, Dryżek P, Bobkowski W, Góreczny S, Mazurek-Kula A, Moll J et al. Original paperPercutaneous interventions in patients with hypoplastic left heart syndrome after stage first Norwood operation. Advances in Interventional Cardiology/Postępy w Kardiologii Interwencyjnej. 2011;7(4):277-284. doi:10.5114/pwki.2011.25785.

Objective To evaluate the outcome of the cardiac catheter angiograplasty for patients after Norwood procedure. Methods 13 patients, who had undergone Norwood procedure (prior to Glenn procedure)received cardiac catheterization and angiography. lnterventional therapy was performed in 12 patients as indicated. Results Angioplasty was carried out for re-coarctation in 6 of the13 patients. 1 patient with left pulmonary artery stenosis received balloon dilation and 3 months later a stent implantation. A stent was implanted to improve the pulmonary blood flow in 2 patients with Sano-Shunt stenosis and 1 patient with BT-Shunt stenosis. Transcatheter coil embolization was performed in 3 of the 4 patients with systemic to pulmonary collateral vessels. The other one was scheduled for Glenn procedure the next day. Conclusion The incidence of hemodynamic restrictions after Norwood procedure is high (12 of 13 patients). Postoperative angiography and hemodynamic assessment for diagnosis and interventional treatment for new pulmonary artery or aortic arch stenosis is necessary after Norwood procedure. Key words: Congenital heart disease, congenital Hypoplastic left heart syndrome Catheterization Angioplasty Norwood procedure

Repair of Ventricular Aneurysm After Stage I Modified Sano-Norwood Procedure

Objective To summarize the preliminary results of transcatheter interventions in patients after bidirectional Glenn shunt(BGS) in single ventricular physiology.Methods In patients with single ventricular physiology after bidirectional Glenn shunt,transcatheter occlusion of aortopulmonary collateral arteries,closure of dilated azygous or /and hemiazygousveins,or/and balloon-dilation of pulmonary artery were selected to undertake,according to their clinical and catheterizational profiles.Results 22 patients aged(9.3 ±4.2) years(3.3-18.9 years),weighted(29 ±13) kg(13-54 kg),(3.1 ±3.8) years(1.0-12.5 years) after bidirectional Glenn shunt,received transcatheter interventions,including occlusion of aortopulmonary collateral arteries in 12 patients,closure of dilated azygous or/and hemiazygous veins in 11 cases,balloon-dilation of stenotic pulmonary arteries in 6 patients.Native pulmonary artery was dilated in 4 cases.The origin of the stenosed left pulmonary artery were dilated in another 2 patients.6 patients had received two kinds of interventions.After these transcatheter interventions,9 cases had received Fontan procedures uneventfully,7 cases were waiting for Fontan operation,and 6 cases presently not suitable for Fontan were closely followed-up with stable cardiac function and saturation of oxygen unchanged.Conclusion In patients with single ventricular physiology after bidirectional Glenn,individualized transcatheterly interventions can improve clinical results,and make condition for the Fontan operation. Key words: Single ventricular ; Bidirectional Glenn operation; Transcatheter intervention ; Aortopulmonary collateral arteries; Systematic venous collaterals ; Pulmonary balloon dilation

Shunts placed between the right ventricle and the pulmonary arteries, called Sano shunts, recently modified Norwood surgery for hypoplastic left heart syndrome. Patients with Sano shunts tend to be more stable thus reducing the interstage mortality of this still challenging complex cardiac anomaly. However, Sano shunt stenosis may develop and is a life threatening complication. We report on our experience in patients with Sano shunt obstruction. Eight infants presenting with decreasing transcutaneous oxygen saturations (43-63%, median 58%) following modified Norwood procedures were shown to have relevant Sano shunt stenosis. None was suited for early stage two surgery (cavopulmonary Glenn anastomosis). Catheterization was performed at the age of 21 to 112 (median 85) days. Weight was 3.9 to 6.0 (median 4.8) kg. Femoral 5F venous access. Long sheaths were not used. The shunt was entered with a 4F right Judkins catheter and a selective angiography was performed. The stenosis was localized proximal in 5, distal in 1 and proximal and distal in 2 patients. Ten coronary stents were implanted. There were no procedure related complications. Oxygen saturation increased immediately to 75-86% (median 80%) and remained above 70% during follow-up in all. Seven patients had successful stage two surgery 61-288 (median 134) days after stent implantation, one is awaiting this. Sano shunt obstruction can be treated safely and effectively by stent implantation. Early in-stent restenosis does not seem to be a problem.

To assess the safety and efficacy of transcatheter intervention for critical pulmonary stenosis (CPS) and pulmonary atresia with intact ventricular septum (PA/IVS) in neonates. From June 2006 to September 2011, 27 neonates including CPS in 19 patients and PA/IVS in 8 patients underwent transcatheter intervention. All patients had membranous stenosis or atresia without severe Ebstein's anomaly and severe right ventricle and pulmonary valve hypoplasia, without right ventricle-dependent coronary circulation in PA/IVS. The mean age was (16.8 ± 9.9) d. The mean weight was (3.3 ± 0.5) kg. Two of them were premature neonates, the weight was 2.3 kg and 2.5 kg, respectively. The procedural success, early outcome, complication rates, midterm results and pulmonary regurgitation were retrospectively studied. Twenty-six patients were successfully treated with transcatheter intervention. Right ventricular pressure fell from (112.0 ± 21.0) mm Hg (1 mm Hg = 0.133 kPa) to (50.4 ± 15.9) mm Hg (P < 0.001). The ratio of right ventricular pressure and aortic pressure fell from 1.7 ± 0.1 to 0.7 ± 0.3 (P < 0.001). One patient died early of PA/IVS. Complication occurred in 5 patients. Hemopericardium occurred in 3 patients, tachyarrhythmia in 2 patients. Five patients needed prolonged prostaglandin E(1) infusion for 3 to 14 days because of desaturation after the procedure. No patient needed surgery in neonatal period. At a mean follow-up of (33.5 ± 18.3) months (from 6 months to 5 years), 21 patients had no further transcatheter or surgical intervention. Four patients with CPS had moderate to severe residual pulmonary stenosis after the procedure, 3 of them underwent a second balloon dilation at 3 months of follow-up, the other one was waiting for the second balloon dilation. One patient with PA/IVS was waiting for a bidirectional Glenn procedure because of chronic right ventricular failure. Mild pulmonary regurgitation occurred in 18 patients (69.2%), and moderate pulmonary regurgitation in 8 patients (30.8%). Transcatheter intervention for CPS and PA/IVS in neonates is safe and effective. It can avoid neonatal surgery. Some patients may require repeat balloon valvuloplasty in infant period. In most patients surgical or transcatheter intervention could be avoided and mild pulmonary regurgitation was the common finding in midterm follow-up.

With improved short-term outcomes the right ventricular to pulmonary artery shunt (Sano) has become the preferred pulmonary blood source in the Norwood procedure in many centres. However, most studies analysed consecutive cohorts, with a first modified Blalock-Taussig shunt (BT) followed by the Sano cohort. Besides, neither comprehensive preoperative risk analysis nor outcome beyond 1 year of age was investigated. This study reviews 109 neonates undergoing the Norwood procedure in the same interval between October 2002 and December 2009. The Sano (38) or BT shunt (71) was assigned according to the surgeon's preference. Two neonates subsequently underwent successful biventricular repair and were excluded. The Aristotle comprehensive score (ACS) was used to evaluate preoperative risk, with high-risk patients (n = 39) classified as having an ACS ≥ 20, and low-risk patients (n = 68) given an ACS <20. Mean Aristotle score at the Norwood operation was 18.8 ± 0.4 and 18.9 ± 0.3 (P = 0.9) in Sano and BT, respectively. Mean follow-up interval was 4.1 ± 2.1 years (range: 1.7-8.9 years). Actuarial survival was similar, stabilizing from the 8th postoperative month onwards at 78.6 ± 4.9% (95% CI: 67.0-86.5%) for Sano and 78.4 ± 6.8% (95% CI: 61.4-88.6%) for BT; P = 0.95. Midterm actuarial survival was higher in low-risk patients, 88.2 ± 3.9% (95% CI: 77.8-93.9%) than in high-risk patients: 61.5 ± 7.8% (95% CI: 44.5-74.7%, P = 0.0003). No survival benefit was detected in low- or high-risk cases for either shunt type. Risk factors for midterm mortality were cardiorespiratory failure requiring ventilation (13/34, P = 0.004), and ACS ≥ 20 (15/39, P = 0.001), but not shunt type (8/37, P = 0.95). Increased number of shunt-related interventions before the Glenn procedure were noted with Sano (32.4 versus 6.5%, P = 0.002). Preoperative risk factors, regardless of shunt type, influence midterm survival after the Norwood procedure with an excellent outcome in low-risk patients, while high-risk cases still incur a significant mortality. Sano shunt interventions occurred with increased numbers. Although, Sano shunt may be the only feasible option in some instances, given the possible negative effects of ventriculotomy on right ventricle function, the widespread use of Sano shunt should be reconsidered.

Objective Norwood StageⅠis the standard procedure to cope with hypoplastic left heart syndrome(HLHS), which continues to be the most challenging congenital heart disease. The aim of this study is to retrospectively analyse the perioperative management of Norwood StageⅠ. Methods Between June 2010 and August 2014, totally 5 small infants with HLHS underwent the standard Norwood StageⅠprocedure. They were all boys. Age at surgeries ranged from 29 to 75 days, and weight from 2.57-3.50 kg with median of 3.13 kg. Case 1, 2 and 3 received standard medical regimen after accessing NICU, which included intravenous prostaglandin E1 and mechanical ventilation. The 3 infants underwent emergent operations because of unstable hemodynamics. Case 4 and 5 received no medical intervention before the urgent surgeries. All 5 cases underwent the standard Norwood StageⅠprocedure under deep hypothermic circulatory arrest, including 4 cases of modified Blalock-Taussig shunt(MBTS) and 1 case of Sano shunt. Results The case with Sano shunt died from severe hypoxemia and persistent acidosis 32 hours after the operation, another case died from low cardiac output syndrome after cardiopulmonary bypass. The first case underwent bidirectional Glenn procedure 12 months after Norwood Stage I, the postoperative heart function was NYHA I and the oxygen saturation was 0.90-0.95 in room air, but he died from accidental brain injury 3 months after stage Ⅱ. The second case was followed up 3 months after stage I procedure with NYHA I and oxygen saturation of 0.78-0.83 in room air, and lost the follow-up after. The fifth case was followed up 3 months after stageⅠprocedure with NYHAⅠ, confluent MBTS and oxygen saturation of 0.84, the patient is being followed up and waiting for further evaluation for stageⅡprocedures. Conclusion The standard Norwood StageⅠprocedure is a complex procedure, which demands multidisplinary cooperation, to palliatively correct HLHS. Sharing expericences on perioperative managements of Norwood Stage I between heart centers in China will be helpful to decrease the mortality and morbidity in relatively short period. Key words: Heart defects, congenital; Hypoplastic left heart syndrome; Norwood procedures, state Ⅰ; Perioperative

A recent modification to the Norwood procedure involving a shunt placed directly from the right ventricle to the pulmonary arteries may improve postoperative haemodynamics. Concerns remain, however, about the potential problems produced by the required ventriculotomy. We compared 76 patients with hypoplastic left heart syndrome who underwent the Norwood procedure, 35 receiving a modified Blalock-Taussig shunt and the remaining 41 a shunt placed directly from the right ventricle to the pulmonary arteries. We reviewed their subsequent progress through the second stage of palliation. A single observer graded right ventricular function, and the severity of tricuspid regurgitation, based on blinded review of the most recent echocardiograms prior to the second stage of palliation. At the time of catheterization prior to the second stage, patients with a shunt placed from the right ventricle to the pulmonary arteries, rather than a modified Blalock-Taussig shunt, had higher arterial diastolic blood pressure, at 44 versus 40 millimetres of mercury, p equal to 0.02, lower ventricular end diastolic pressures, at 8 versus 11 millimetres of mercury, p equal to 0.0002, and larger pulmonary arteries as judged using the Nakata index, at 270 versus 188 millimetres squared per metres squared, p equal to 0.009. There was no difference in qualitative ventricular systolic function or tricuspid regurgitation between groups. No differences were found between groups during the hospitalization following the second stage of palliation. A trend towards improved survival to the second stage was seen following the construction of a shunt from the right ventricle to the pulmonary arteries. Construction of a shunt from the right ventricle to the pulmonary arteries is associated with lower right ventricular end diastolic pressures, larger pulmonary arterial size, and higher systemic arterial diastolic pressures. No apparent deleterious effects of the right ventriculotomy were observed in terms of qualitative ventricular systolic function or tricuspid regurgitation.

10. The modified blalock € taussig shunt versus right ventricle to pulmonary artery shunt for stage one norwood procedure: An 11 year experience

The Single Ventricle Reconstruction trial: The gift that keeps on giving

Source: Ohye RG, Sleeper LA, Mahony L, et al. Comparison of shunt types in the Norwood procedure for single-ventricle lesions. N Engl J Med. 2010; 362(21): 1980– 1992; doi: 10.1056/NEJMoa0912461The Pediatric Hear t Network conducted a clinical trial at 15 North American centers of infants with hypoplastic left heart syndrome (HLHS) or related single right ventricle anomalies who were scheduled for a stage I repair (Norwood procedure) and were randomized to have either a Sano (right ventricle to pulmonary artery [RVPA]) shunt or a modified Blalock Taussig (MBT, subclavian artery to PA) shunt to provide pulmonary blood flow. The primary outcome was death or cardiac transplantation within 12 months following the intervention. Secondary outcomes included morbidity during the hospitalizations for the Norwood and the stage II (Bidirectional Glenn) procedures; unintended cardiovascular interventions involving the shunt; function and volume of the right ventricle; and the amount of tricuspid-valve regurgitation at discharge following the Norwood procedure, before stage II, and at 14 months of age.The study enrolled 555 infants but six were excluded from the analysis (5 did not receive the intervention and 1 was lost to follow-up). The two equally divided groups did not differ in initial clinical characteristics. Twelve months after randomization, primary outcome events occurred in 72 (68 deaths and 4 transplantations) of the 274 infants (26.3%) assigned to the RVPA group as compared to 100 events (91 deaths and 9 transplantations) of the 275 infants (36.4%) assigned to the MBT group. However, there was no difference in transplantation-free survival between the two groups with continued follow-up to a mean of 32 months after the stage I procedure.During the 12 months following the Norwood procedure, infants in the RVPA shunt group underwent more unplanned cardiovascular interventions (92 vs 70 per 100 infants, P=.003) primarily due to the higher need for balloon dilation or stent placement in the shunt or a branch of the PA. The rate of complications was also higher in the RVPA shunt group (5.3 vs 4.7 complications per infant, P=.002), although the proportion of infants with at least one complication was the same (91%). The authors concluded that continued follow-up beyond 12 months is needed to determine which of the two shunts to establish pulmonary blood flow is superior.HLHS occurs in 1 of 5,000 live births.1 Infants with HLHS require surgical therapy to establish adequate systemic blood flow that is separate from the pulmonary circulation. The risk of death is high, especially during the initial Norwood surgery and the interstage period until a bidirectional cavopulmonary anastomosis (Stage II procedure) is performed. This time period encompasses the duration the child has single ventricle physiology — approximately the first six months of life.Much interest was generated when Sano and colleagues first described their success modifying the source of pulmonary blood flow from an arterial (MBT) to a ventricular (RVPA) shunt for the first stage palliation pioneered by Norwood and colleagues.2,3 Results from several institutions demonstrated that an RVPA shunt improved survival through the period of single ventricle physiology compared to a MBT shunt, perhaps due to better coronary perfusion associated with higher diastolic blood pressure. However, concern persisted that the physiologic advantages of a RVPA shunt for early survival may be offset by the adverse effects of the required ventriculotomy on long-term cardiac function and arrhythmogenesis.To address these concerns, in the current study the Pediatric Heart Network completed a randomized trial of shunt type for initial surgical palliation. The results validate the survival advantage of the ventricular shunt for the first year after the initial surgery, but found no difference in transplant-free survival between groups after one year.Echocardiography is the primary method for assessment of ventricular function over time. Previous data comparing ventricular function between shunt types is limited, and in the current trial echocardiography findings at 14 months post initial palliation did not differ between the two shunt types. Nonetheless, other reports of concerning findings, including pathological specimens showing fibrosis and collagen changes4 and catheterization findings suggesting decreased cardiac contractility5 in RVPA shunts are concerning. Additional follow-up of the population in this study should further elucidate whether a RVPA shunt negatively impacts ventricular function in the long term compared to the MBT. Thus far there have been few reports of arrhythmias in HLHS patients with either shunt type.6Congenital heart research teams plan a more detailed analysis of data from this trial and continued follow-up of this population. The important message for primary care physicians who take care of patients with HLHS and their families is that the morbidity and mortality do not vanish after the stage II procedure regardless of shunt type. Close follow-up is required to allow timely interventions.