Norwood procedure for hypoplastic left heart syndrome associated with valvular pulmonary stenosis

Association between hypoplastic left heart syndrome and valvular pulmonary stenosis is very rare. Severity of valvular pulmonary stenosis in this setting limits management options. Consequently, patients with this condition are considered poor candidates for Norwood stage one reconstruction. Herein, we describe a newborn with hypoplastic left heart syndrome and significantly dysplastic pulmonary valve who successfully underwent the Norwood procedure with neoaortic valve reconstruction. Therefore, the Norwood procedure with neoaortic valve reconstruction might be an option for this difficult condition.     

Norwood with right ventricle-to-pulmonary artery conduit is more effective than Norwood with Blalock–Taussig shunt for hypoplastic left heart syndrome: mathematic modeling of hemodynamics

Objective: The introduction of right ventricle to pulmonary artery (RV-PA) conduit in the Norwood procedure for hypoplastic left heart syndrome resulted in a higher survival rate in many centers. A higher diastolic aortic pressure and a higher mean coronary perfusion pressure were suggested as the hemodynamic advantage of this source of pulmonary blood flow. The main objective of this study was the comparison of two models of Norwood physiology with different types of pulmonary blood flow sources and their hemodynamics. Method: Based on anatomic details obtained from echocardiographic assessment and angiographic studies, two three-dimensional computer models of post-Norwood physiology were developed. The finite-element method was applied for computational hemodynamic simulations. Norwood physiology with RV-PA 5-mm conduit and Blalock–Taussig shunt (BTS) 3.5-mm shunt were compared. Right ventricle work, wall stress, flow velocity, shear rate stress, energy loss and turbulence eddy dissipation were analyzed in both models. Results: The total work of the right ventricle after Norwood procedure with the 5-mm RV-PA conduit was lower in comparison to the 3.5-mm BTS while establishing an identical systemic blood flow. The Qp/Qs ratio was higher in the BTS group. Conclusions: Hemodynamic performance after Norwood with the RV-PA conduit is more effective than after Norwood with BTS. Computer simulations of complicated hemodynamics after the Norwood procedure could be helpful in establishing optimal post-Norwood physiology.     

Follow-up study of pulmonary artery configuration in hypoplastic left heart syndrome

Objective. Pulmonary artery (PA) distortion significantly compromises the outcome of the staged approach to the Fontan operation in patients with hypoplastic left heart syndrome (HLHS). This retrospective study was designed to investigate the influence of the initial operation on postoperative PA anatomy. Methods. Forty-nine patients with HLHS and its variant were enrolled in this study. As an initial palliation, the Norwood operation with a modified Blalock-Taussig (BT) shunt was performed in 12, the Norwood operation with a right ventricle to pulmonary artery (RV-PA) shunt in 31, and bilateral PA banding in 6. The incidence and risk factors of postoperative central pulmonary artery stenosis (PS) were investigated, and the PA configuration was followed up until post-Fontan status. Results. Twenty-two patients (51.2%) had developed central PS after the Norwood operation (33.3% with a BT shunt vs. 58.1% with a RV-PA shunt). The RV-PA shunt with a polytetrafluoroethylene (PTFE) patch at the distal pulmonary stump significantly decreased the central PS (P = 0.035). The PA index after the Norwood operation was not statistically different between the BT and RV-PA shunt groups, although in the RV-PA group it was significantly higher in patients with a PTFE patch on the distal PA stump. PA plasty was performed in 16 patients in the second-stage palliation and in 15 with the Fontan completion. Freedom from PA plasty was significantly lower in the RV-PA shunt group than in the BT shunt group (63.5% vs. 31.1% at 5 years, P = 0.034). Six patients initially palliated with bilateral PA banding had no stenosis at the banding site in the Norwood + Glenn operation, and one patient required stent placement for left PS in the Fontan completion. Post-Fontan catheterization (n = 31) showed central venous pressure of 11.5 ± 2.6 mmHg, cardiac index of 3.6 ± 0.8 l/kg/min, and PA index of 194.0 ± 58.4 mm²/m²; there was no difference between the groups. Conclusion. The incidence of central PS after the Norwood operation was significant, and the shunt type and procedure for the distal PA stump influenced the postoperative configuration of the central PA. With an aggressive surgical approach to central PS, PA anatomy was satisfactory with good hemodynamic variables after Fontan completion. Bilateral PA banding did not cause later vascular deformity. Presented at the 59th Annual Scientific Meeting of the Japanese Association for Thoracic Surgery, held in Tokyo, Japan, October 1–4, 2006     

Norwood procedure to hypoplastic left heart syndrome

Since March 1992, 25 neonates and small infants with HLHS have undergone a modified Norwood procedure. The mean age and weight at operation were 17 days (2 days-2 months) and 2.7 kg (1.6–3.3 kg). Isolated cerebral and/or myocardial perfusion (ICMP) with direct anastomosis of aorta and pulmonary artery was utilized since January 1995 to 16 patients. Under median sternotomy, PTFE graft (usually 3.0–3.5 mm) was anastomosed to the brachiocephalic artery and the arterial cannula was inserted to this PTFE graft. The left carotid and the left subclavian arteries were snared and a clamp was placed on the aortic arch just distal to the brachiocephalic artery. This allowed blood to enter the brain and the coronary arteries, keeping the brain perfused and the heart-beating. After reconstruction of distal aortic arch, a single dose of crystalloid cardioplesia was infused and the rest of the arch was reconstructed. There were 14 early deaths (56%) and 4 late deaths (16%). Bidirectional Glenn procedure was performed to 5 patients with 1 death. Three patients underwent modified Fontan procedure without mortality. Mean aortic cross clamp time was 24 min. and mean ICMP time was 32 min. There was no neurologic complications. In conclusion, isolated cerebral and/or myocardial perfusion may offer an advantage of protecting the brain and myocardium during arch repair in Norwood procedure.     

Anesthetic management of the hybrid stage 1 procedure for hypoplastic left heart syndrome (HLHS)

Introduction: Despite advances in the surgical and perioperative management of patients with hypoplastic left heart syndrome (HLHS), outcomes for this high‐risk group of patients remains suboptimal. The hybrid approach [bilateral pulmonary artery (PA) banding, ductal stenting, balloon atrial septostomy], is an emerging alternative therapy for the management of HLHS, which defers the risks of a major surgical repair until the infants are older. This article will describe our experience providing the anesthetic management of patients undergoing the hybrid procedure. Methods: After Institutional Review Board approval, we retrospectively reviewed the records of 77 patients who underwent the hybrid procedure as neonates between July 2002 and August 2008. We reviewed both the anesthetic and intensive care records. Results: The hybrid procedure was performed in 77 patients (31 female and 46 male). The average age of the patients was 11.8 days with an average weight of 2.98 kg. Fentanyl was used for analgesia at an average dose of 5.7 mcg·kg^?1. The average increase in the systolic blood pressure after placement of the right and left PA bands was 11.3 mmHg. The average drop in the systemic saturation after placement of the bands was 7%, with an average postband and stent SaO₂ of 82%. Twenty‐one patients received blood transfusion (27.3%) at an average dose of 43.5 ml (14.5 ml·kg^?1). Forty patients received albumin during the case (51.9%) at an average dose of 23.2 ml (7.7 ml·kg^?1). Seventeen patients arrived at the hybrid suite already intubated, and no attempt was made to extubate these patients at the end of the case. Thirty‐six patients were extubated at the end of the procedure, and a total of 64.9% of patients were extubated within the first 24 h postoperatively. Patients had notably stable hemodynamics throughout the first 24 h in the intensive care unit. Discussion: Patients undergoing the hybrid procedure have relatively stable intraoperative and early postoperative hemodynamics. The procedure is performed without cardiopulmonary bypass (CPB) and with minimal narcotic and anesthetic exposure. Patients typically do not require blood transfusions or inotropic support and are extubated at either the end of the procedure or within 24 h of ICU admission. In our experience, the anesthetic management of patients undergoing the hybrid procedure is straightforward and requires relatively few interventions when compared to traditional neonatal surgical repairs. Deferring the risks of anesthesia, CPB, hypothermic circulatory arrest, and prolonged postoperative sedation may yield developmental advantages to patients born with HLHS.     

Norwood-I in a hypoplastic left heart variant and right aortic arch

Even though preoperative diagnostics have improved significantly, intraoperative surprises may still occur especially in the case of complex congenital heart disease. An instance of such a complex congenital heart disease is a hypoplastic left heart syndrome with a right-sided aortic arch. In this case report, we present 1 patient with such a complex and unexpected anatomy, as well as a possible way to overcome the obstacles.     

Right ventricle-to-pulmonary artery shunt and modified Blalock–Taussig shunt in preparation to hemi-Fontan procedure in children with hypoplastic left heart syndrome

Objective: The advantageous effect of right ventricle-to-pulmonary artery shunt (RV–PA) on the early postoperative hemodynamics in the Norwood procedure for hypoplastic left heart syndrome (HLHS) is well known. Numerous controversies still exist with respect to the late consequences of this new palliation method in preparation for the second stage procedure. Methods: Between September 1997 and September 2004, a consecutive series of 78 children with HLHS from a single institution underwent the hemi-Fontan procedure: Group 1 (n=27) after Blalock–Taussig shunt (BT), and Group 2 (n=51) after RV–PA. Hemodynamic, echocardiographic and clinical perioperative data were analyzed. Results: There were no significant differences in the age and operative weight (Group 1: 6.9±1.04 months, 6.22±0.99 kg; Group 2: 6.57±1.12 months, 6.36±0.86 kg). Children after RV–PA were characterized by a significantly higher preoperative hematocrit value (P=0.014), lower aortic and superior vena cava oxygen blood saturation (P<0.001, P=0.024), severe right ventricle hypertrophy more rarely diagnosed in echocardiography (P<0.004), lower Qp:Qs ratio (P=0.011), larger right (P=0.001) and left (P=0.006) pulmonary artery index and a shorter intensive care unit stay after the hemi-Fontan procedure (P=0.004). Conclusions: The Norwood procedure with the RV–PA shunt provides satisfactory late hemodynamics and improves the development of the pulmonary arteries. Children with hypoplastic left heart syndrome subjected to this new method of palliation are good candidates for the hemi-Fontan procedure.     

Norwood procedure to hypoplastic left heart syndrome]

Since March 1992, 25 neonates and small infants with HLHS have undergone a modified Norwood procedure. The mean age and weight at operation were 17 days (2 days-2 months) and 2.7 kg (1.6-3.3 kg). Isolated cerebral and/or myocardial perfusion (ICMP) with direct anastomosis of aorta and pulmonary artery was utilized since January 1995 to 16 patients. Under median sternotomy, PTFE graft (usually 3.0-3.5 mm) was anastomosed to the brachiocephalic artery and the arterial cannula was inserted to this PTFE graft. The left carotid and the left subclavian arteries were snared and a clamp was placed on the aortic arch just distal to the brachiocephalic artery. This allowed blood to enter the brain and the coronary arteries, keeping the brain perfused and the heart-beating. After reconstruction of distal aortic arch, a single dose of crystalloid cardioplesia was infused and the rest of the arch was reconstructed. There were 14 early deaths (56%) and 4 late deaths (16%). Bidirectional Glenn procedure was performed to 5 patients with 1 death. Three patients underwent modified Fontan procedure without mortality. Mean aortic cross clamp time was 24 min. and mean ICMP time was 32 min. There was no neurologic complications. In conclusion, isolated cerebral and/or myocardial perfusion may offer an advantage of protecting the brain and myocardium during arch in Norwood procedure.     

Technical description of the use of selective perfusion techniques during the Norwood procedure for hypoplastic left heart syndrome

Since the introduction of the Norwood procedure for surgical palliation of hypoplastic left heart syndrome in 1983, refinements have been made to the original procedure to improve patient outcomes while still accomplishing the original goals of the procedure. One of these refinements has been the introduction of regional selective perfusion to limit the duration of circulatory arrest times and optimize the regional flow distribution. In this paper we describe our technique for performing selective cerebral and lower body perfusion during the Norwood procedure.     

Tricuspid valve repair in hypoplastic left heart syndrome

OBJECTIVES: Currently, the survival for the Norwood procedure for hypoplastic left heart syndrome is approximately 90% in selected centers. However, the development of tricuspid regurgitation remains a significant obstacle to successful staged repair in a subset of these patients. The results of tricuspid valve repair in this challenging patient population remain largely unknown. METHODS: Twenty-eight patients with significant (3-4+) tricuspid regurgitation after the Norwood procedure required tricuspid valve repair from August 1995 through December 2002. The clinical and Doppler-echocardiographic data were reviewed to determine the efficacy of repair and patient outcome. RESULTS: Follow-up was 96% complete (27/28). Patients were divided into 2 groups on the basis of tricuspid regurgitation at late follow-up: those with a successful late outcome (0-2+) and those with a poor outcome (3-4+). There were 17 (63%) patients with a successful result and 10 (37%) with an adverse outcome. Age, weight, follow-up duration, valve anatomy, and stage of palliation were not significantly different between groups. Early postoperative 0 to 2+ regurgitation was associated with a durable result (P =.012) and preserved ventricular function (P =.04). Need for repair other than a partial annuloplasty was predictive of a poor outcome (P =.04). Overall survival was 67% (18/27). Survival was 94% (16/17) for patients with a successful late result versus 20% (2/10) for those with a poor outcome (P =.0002). CONCLUSIONS: Tricuspid valve repair can be accomplished in this challenging patient population with excellent results. Successful tricuspid valve repair is predictive of continued good valve function and preserved right ventricular function. Successful valve repair at late follow-up predicts excellent late survival.     

Edge-to-edge tricuspid valve repair in hypoplastic left heart syndrome

Tricuspid regurgitation (TR) is known to be a risk factor for mortality in the surgical management of patients with hypoplastic left heart syndrome (HLHS). Concomitant repair for TR should be considered when the TR is moderate to severe to achieve successful Fontan completion. The present case was a 20-month-old girl who was diagnosed with HLHS (mitral atresia and aortic atresia). She underwent a Norwood procedure as the first palliation followed by a Glenn procedure. After that, she gradually developed TR, which progressed to a severe state at the time of the Fontan procedure. An edge-to-edge tricuspid valve repair, in which the anterior and septal leaflets were sutured together, was performed simultaneously with the extracardiac Fontan procedure. Discharge echocardiography revealed that the degree of TR was less than mild. The technique is simple, not time-consuming, and may be an effective adjunct for successful completion of the Fontan procedure in these patients.