Single-ventricle physiology: perioperative implications

Review of cardiac-coronary interaction and insights from mathematical modeling

Cardiac-coronary interaction is fundamental to the function of the heart. As one of the highest metabolic organs in the body, the cardiac oxygen demand is met by blood perfusion through the coronary vasculature. The coronary vasculature is largely embedded within the myocardial tissue which is continually contracting and hence squeezing the blood vessels. The myocardium-coronary vessel interaction is two-ways and complex. Here, we review the different types of cardiac-coronary interactions with a focus on insights gained from mathematical models. Specifically, we will consider the following: (1) myocardial-vessel mechanical interaction; (2) metabolic-flow interaction and regulation; (3) perfusion-contraction matching, and (4) chronic interactions between the myocardium and coronary vasculature. We also provide a discussion of the relevant experimental and clinical studies of different types of cardiac-coronary interactions. Finally, we highlight knowledge gaps, key challenges, and limitations of existing mathematical models along with future research directions to understand the unique myocardium-coronary coupling in the heart. This article is categorized under: Cardiovascular Diseases > Computational Models Cardiovascular Diseases > Biomedical Engineering Cardiovascular Diseases > Molecular and Cellular Physiology.

Hemodynamic Response to Fluid Boluses in Patients with Single-Ventricle Parallel Circulation

The purpose of this study is to assess the effect of fluid bolus in response to a hypotensive episode by evaluating high-fidelity hemodynamic data obtained from children with single-ventricle anatomy and parallel circulation. Single center, retrospective analysis of hemodynamic and oximetric data after fluid bolus administrations within the first 2 weeks post-surgery. A baseline (- 60 to - 10 min), hypotensive episode (- 10 to 0 min), and response interval (0 to 60 min) were defined to quantify the dynamics of vital signs. The responses assessed include heart rate, blood pressure, oxygen saturation, oxygen extraction ratios, and pulmonary-to-systemic flow ratios. Mixed effects models were used to account for the repeated measures over the response interval. The analysis included 67 fluid boluses. There is a decrease in heart rate and an increase in blood pressure during the response in comparison to the hypotensive time. These vitals rapidly return to the baseline values. The boluses induced a significant decrease in renal and cerebral oxygen extraction ratios, with no significant change in arterial oxygen saturation or pulmonary-to-systemic flow ratio. The type of bolus (normal saline versus albumin) did not affect the response in blood pressure. However, in comparison with albumin, normal saline had a more favorable effect on the renal and cerebral oxygen extraction ratios. This study demonstrates that fluid boluses are an effective rescue medication for hypotensive episodes in children with parallel circulation by improving hemodynamics, as well as markers of oxygen delivery. The type of bolus (normal saline versus albumin) did not affect the blood pressure response. However, normal saline had a more pronounced effect on the renal and cerebral oxygen extraction ratios than albumin.

Perioperative Management of a Child with Hypoplastic Left Heart Syndrome Undergoing Cryptorchidism Surgery

Hypoplastic left heart syndrome (HLHS) is a complex congenital heart condition which includes abnormal development of left sided cardiac structures leading to inadequate systemic perfusion following postnatal closure of the patent ductus arteriosus (PDA). Surgical palliation may be accomplished through a 3 staged process -Norwood procedure. This surgery is usually done within the first two weeks of your child's life -Bidirectional Glenn procedure. This procedure is generally the second surgery. It's done when your child is between 3 and 6 months of age. -Fontan procedure. This surgery is usually done when your child is between 18 months and 4 years of age. Patients with HLHS may need to undergo other non-cardiac surgical procedures during the first years of life posing a real challenge to the anesthesiologist, surgeon and the entire medical team. We present the case of a 18-months old, 9 kg infant who presented for cryptorchidism surgery. Cryptorchidism or undescended testis (UDT) is one of the most common pediatric disorders of the male endocrine glands and the most common genital disorder identified at birth. The main reasons for treatment of cryptorchidism include increased risks of impairment of fertility potential, testicular malignancy, torsion and/or associated inguinal hernia. The intraoperative implications of the hybrid anatomy are discussed, options for anesthetic care presented, and previous reports of anesthetic care for such patients reviewed. Conclusion: LMA combined with local anesthesia was effective to maintaining optimal cardiac function of this child patient with HLHS In summary, children with palliated HLHS have anesthetic considerations that must be followed in order to reduce perioperative morbidity and mortality in this high-risk pathology.

Surgical Correction of Scoliosis in Children with Severe Congenital Heart Disease and Palliated Single Ventricle Physiology

STUDY DESIGN

Case series.

OBJECTIVE

In this study we focus on this group, and describe the largest cohort to date of single ventricle patients undergoing surgical correction of scoliosis at a single institution.

SUMMARY OF BACKGROUND DATA

Outcomes of spinal surgery for patients with congenital heart disease (CHD) have evolved and most affected patients have uncomplicated procedures. The risk of perioperative complications remains highest in patients with single ventricle ("Fontan") physiology.

METHODS

We reviewed patients with single ventricle CHD and operative scoliosis repair over a 25-year span. Patients who had undergone a Fontan, bidirectional Glenn, and/or Kawashima procedure before operative scoliosis repair were included. Patients were excluded if they lacked preoperative cardiac care and/or sufficient medical history at our institution.

RESULTS

Twenty-three patients were included. The average age at surgery was 13.6 years (range, 5-23). Seventy percent of the cohort was female (16/23). The majority of patients underwent a Fontan before scoliosis surgery (20/23, 87%). Patients without intraoperative tranexamic acid (TXA) had a 67% complication rate (8/12) versus 36% (4/11) in those with intraoperative TXA (P = 0.29). There was a significant difference in estimated blood loss by weight (cc/kg) between non-TXA and TXA patients (P = 0.016). Twelve patients experienced complications (52%), all of which occurred postoperatively. There were no deaths, cerebrovascular events, adverse perioperative cardiac or hemodynamic complications, or wound infections. Using the Clavien-Dindo-Sink classification for postoperative complications, four patients had serious adverse events, including one permanent neurologic deficit.

CONCLUSION

Spinal surgery for scoliosis has been performed in selected patients with single ventricle physiology at a single institution without mortality for 25 years. Operative blood loss may be reduced by routine use of TXA. Complications occur most commonly in the postoperative period, and can include pleural effusion.Level of Evidence: 4.

International Survey on the Use of Arginine Vasopressin in the Postoperative Management of Single Ventricle Patients

Management of patients with single ventricle physiology after surgical palliation is challenging. Arginine vasopressin has gained popularity in recent years as a non-catecholamine vasoactive medication due to its unique properties. However, data regarding its use in the pediatric population is limited. Therefore, we designed a survey to explore whether and how clinicians use this medication in intensive care units for the postoperative management of single ventricle patients. This international survey aimed to assess usage, practices, and concepts related to arginine vasopressin in pediatric intensive care units worldwide. Directors of pediatric intensive care units who are members of the following international professional societies: European Society of Pediatric Neonatal Intensive Care, Association for European Pediatric and Congenital Cardiology, and Pediatric Cardiac Intensive Care Society were invited to participate in this survey. Of the 62 intensive care unit directors who responded, nearly half use arginine vasopressin in the postoperative management of neonatal single ventricle patients, and 90% also use the drug in subsequent surgical palliation. The primary indications are vasoplegia, hemodynamic instability, and refractory shock, although it is still considered a second-line medication. Conceptual benefits include improved hemodynamics and end-organ perfusion and decreased incidence of low cardiac output syndrome. Those practitioners who do not use arginine vasopressin cite lack of availability, fear of potential adverse effects, unclear indication for use, and lack of evidence suggesting improved outcomes. Both users and non-users described increased myocardial afterload and extreme vasoconstriction as potential disadvantages of the medication. Despite the lack of conclusive data demonstrating enhanced clinical outcomes, our study found arginine vasopressin is used widely in the care of infants and children with single ventricle physiology after the first stage and subsequent palliative surgeries. While many intensive care units use this medication, few had protocols, offering an area for further growth and development.

Risk Recognition and Multidisciplinary Approach for Non-Cardiac Surgeries in Paediatric Cardiac Patients: A Retrospective Observational Study

Background

Congenital heart disease (CHD), a structural and functional heart disease, is the commonest birth defect with an incidence of one in 125 live births worldwide with ventricular septal defect (VSD), atrial septal defect (ASD) and tetralogy of Fallot (TOF) constituting the majority. Surgery for associated extra-cardiac anomalies (airway, skeletal, genitourinary, and gastrointestinal) may be required in 30% of these patients. Delivery of uneventful anaesthesia in these children requires an understanding of not only paediatric anaesthesia but also of the pathophysiology of the cardiac lesion and its associated risks.

Aims

The purpose of this retrospective review was to highlight the approach to the anaesthetic management and outcomes of patients with significant cardiac lesions presenting for non-cardiac surgeries.

Material and methods

A retrospective chart review of all children with congenital heart disease (CHD) (repaired or unrepaired) who were posted for a non-cardiac surgery in this tertiary care Paediatric super-specialty hospital from January 1, 2018 to December 31, 2019 was carried out. Data on demographics, peri-operative management, and clinical course was retrieved.

Inclusion criteria were paediatric patients (0-18 years) of either gender with a diagnosis of a CHD (repaired or unrepaired) undergoing any non-cardiac surgeries (NCS) under anaesthesia/Monitored Anaesthesia Care (MAC).

Exclusion criteria were procedures only under local anaesthesia (LA) or a minor procedure done solely under sedation not involving an anaesthesiologist.

Results

During the study period, we found five eligible cases who underwent a total of six procedures. Five procedures were elective and one was an emergency. Preoperative optimization was conducted by a multidisciplinary team including paediatric surgeons, anaesthesiologists, physicians, and cardio-thoracic surgeons. Anaesthesia was conducted by at least a consultant paediatric anaesthesiologist. Overall all patients tolerated anaesthesia well without any adverse events or complications. All six anaesthetic encounters were safe and uneventful.

Superior Cavopulmonary Connection: Its Physiology, Limitations, and Anesthetic Implications

The superior cavopulmonary connection (SCPC) or "bidirectional Glenn" is an integral, intermediate stage in palliation of single ventricle patients to the Fontan procedure. The procedure, normally performed at 3 to 6 months of life, increases effective pulmonary blood flow and reduces the ventricular volume load in patients with single ventricle (parallel circulation) physiology. While the SCPC, with or without additional sources of pulmonary blood flow, cannot be considered a long-term palliation strategy, there are a subset of patients who require SCPC palliation for a longer interval than the typical patient. In this article, we will review the physiology of SCPC, the consequences of prolonged SCPC palliation, and modes of failure. We will also discuss strategies to augment pulmonary blood flow in the presence of an SCPC. The anesthetic considerations in SCPC patients will also be discussed, as these patients may present for noncardiac surgery from infancy to adulthood.

A rare case of adult congenital heart disease: single ventricular chamber with anomalous right coronary artery in an octogenarian

Patients with single-ventricle physiology encompass a wide array of anatomic subtypes, including but not limited to: tricuspid atresia, hypoplastic left heart syndrome, double-outlet or double-inlet ventricles. The outcomes for patients with single ventricle born before 1990 are relatively poor.

An 81-year-old female presented to the hospital as non-ST elevation myocardial infarction. She was started on antiplatelet and anticoagulation. Echocardiogram revealed a single ventricle which was thought to be left ventricle with possible transposition of great vessels.

Angiography was performed that identified the single ventricle and anomalous origin of the right coronary artery (RCA). She was also found to have double vessel coronary artery disease with diffuse stenosis of mid-RCA at 80% and proximal circumflex at 95%. She was managed conservatively as was high risk for CABG given her rare congenital condition.

Patients with single ventricle are at risk of long-term morbidity, including heart failure, neurological injury, and early death. The mortality risk of these patients is high as most of the patients without corrective surgery do not proceed to adulthood.

Our case had multivessel coronary artery stenosis along with a rare presentation of congenital heart disease in adulthood. The patient was offered percutaneous coronary intervention, but she declined and chose to be treated conservatively with only medical management.

We present a rare case of an elderly female surviving with a single ventricular chamber. The patient is an exception to the usual process of the pathology as most patients without corrective surgery seldom survive into adulthood.

State of the Art: Tissue Engineering in Congenital Heart Surgery

Congenital heart disease is the leading cause of death secondary to congenital abnormalities in the United States and the incidence has increased significantly over the last 50 years. For those defects requiring surgical repair, bioprosthetic xenografts, allografts, and synthetic materials have traditionally been used. However, none of these modalities offer the potential for growth and accommodation within the pediatric population. Tissue engineering has been an area of great interest in a variety of cardiac applications as an innovative solution to create a product that can grow and regenerate within the body over time. Over the last 30 years, the original tissue engineering paradigm of a scaffold seeded with cells and cultured in a bioreactor has been expanded upon to include innovative methods of decellularization and production of "off-the-shelf" tissue-engineered products capable of in situ host cell repopulation. Despite progress in conceptual design and promising clinical results, widespread use of tissue-engineered products remains limited due to both regulatory and ongoing scientific challenges. Here, we describe the current state of the art with regards to in vitro, in vivo, and in situ tissue engineering as applicable within the field of congenital heart surgery and provide a brief overview of challenges and future directions.

Anaesthetic management of a patient with Fontan physiology for electrophysiology study and catheter ablation

The success of the Fontan procedure for congenital single ventricle anatomy has resulted in adult patients with Fontan physiology requiring anaesthesia for cardiac and non-cardiac procedures. We present the perioperative management of a patient with Fontan physiology who underwent electrophysiological study with radiofrequency ablation for atrial tachycardia under general anaesthesia. Good communication between the multidisciplinary teams, a detailed understanding of the patient's complex cardiac anatomy and physiology, as well as the ability to recognise and manage perioperative complications all play a vital role for a successful outcome.

Lumped parameter model for hemodynamic simulation of congenital heart diseases

The recent development of computer technology has made it possible to simulate the hemodynamics of congenital heart diseases on a desktop computer. However, multi-scale modeling of the cardiovascular system based on computed tomographic and magnetic resonance images still requires long simulation times. The lumped parameter model is potentially beneficial for real-time bedside simulation of congenital heart diseases. In this review, we introduce the basics of the lumped parameter model (time-varying elastance chamber model combined with modified Windkessel vasculature model) and illustrate its usage in hemodynamic simulation of congenital heart diseases using examples such as hypoplastic left heart syndrome and Fontan circulation. We also discuss the advantages of the lumped parameter model and the problems for clinical use.

Complex effects of high-flow nasal cannula therapy on hemodynamics in the pediatric patient after cardiac surgery

Background

The high-flow nasal cannula (HFNC) system has been widely used for children in various clinical settings. However, the physiological and clinical impact of HFNC therapy on the pediatric patient with respiratory distress after cardiac surgery has not been thoroughly investigated.

Main body of the abstract

It seems logical to use HFNC as a primary therapy for post-extubation respiratory failure after congenital heart surgery, in which low cardiac output syndrome and upper airway obstruction are commonly encountered; the HFNC therapy alleviates the work of breathing and large negative swings of intrathoracic pressure, which in turn helps to decrease the systemic ventricular afterload. When applying HFNC to patients after congenital heart surgery, however, consideration must be given to its diverse effects on hemodynamics because of the complex respiratory and cardiac pathophysiology in these patients. The positive pressure generated by HFNC can exert different effects on pulmonary vascular resistance depending on the lung condition, while its impact on cardiac output may also differ depending on the cardiac physiology. The hemodynamic effects of HFNC may become even more complex in a patient with a single ventricle. To better assess its physiologic effects in patients after cardiac surgery, future studies could utilize various modalities including esophageal balloon catheters, electrical impedance tomography, and near-infrared spectroscopy. At the same time, studies should focus on specific types of cardiac pathophysiology or surgery when evaluating the effects of HFNC, since it may exert various effects, depending on the cardiac physiology or preoperative pulmonary hemodynamics. Lastly, the optimal flow rate at which the benefit of HFNC is maximized through favorable cardiopulmonary interactions should be determined in future studies.

Short conclusion

Further studies are needed to better understand the effect of HFNC in different cardiac and respiratory physiologies, given their complexity in pediatric patients after cardiac surgery.

Laparoscopic Nissen fundoplication in infants with hypoplastic left heart syndrome

BACKGROUND/PURPOSE

Patients with hypoplastic left heart syndrome (HLHS) experience a higher risk for complications from gastroesophageal reflux, prompting frequent need for fundoplication. Patients between stage I and II palliation ("interstage") are at particularly high operative risk because of the parallel nature of their pulmonary and systemic blood flow. Laparoscopic approach for fundoplication is common for pediatric patients. However, its safety in interstage HLHS is relatively unknown. We examined the perioperative physiologic burden of a laparoscopic fundoplication in HLHS patients.

METHODS

All patients who underwent open or laparoscopic fundoplication during the interstage period at our institution since 2006 were reviewed. Perioperative physiologic data, echocardiographic findings, survival, and complications were collected from the anesthetic record and patient chart.

RESULTS

Nineteen patients with HLHS had laparoscopic fundoplication, 13 (68%) during the interstage period, compared to 64 performed by the open approach. Ten (77%) of 13 interstage patients had perioperative hemodynamic instability. Incidence of instability between open and laparoscopic groups was not different. One laparoscopic patient required ECMO support for shunt thrombosis.

CONCLUSIONS

Despite a high incidence of hemodynamic instability, overall outcomes are consistent with those reported in the literature for this high-risk patient population. Laparoscopic approach for fundoplication during the interstage period appears to be a relatively safe option for these patients.

Amino-Terminal proB-Type Natriuretic Peptide Levels in the Umbilical Cord Blood of Neonates Differ According to the Type of Prenatally Diagnosed Congenital Heart Disease

The aim of this study was to investigate differences in amino-terminal proB-type natriuretic peptide (NT-proBNP) levels in the cord blood of neonates according to the type of congenital heart disease (CHD) and to evaluate the usefulness of NT-proBNP as a prognostic marker. We included 76 neonates with prenatally diagnosed CHD and 45 controls without CHD. Neonates were classified into five groups based on echocardiographic findings. The levels of NT-proBNP in the cord blood were examined and analyzed according to the neonatal outcomes. The levels of NT-proBNP were significantly elevated in the cord blood of neonates with CHD compared with that in the cord blood of controls. The levels of NT-proBNP in the group with right ventricular outflow tract obstruction without a ventricular septal defect were significantly increased compared to that in the other groups. The neonates that required acute surgical correction had higher levels of NT-proBNP in the cord blood, though they were not statistically significant. Meanwhile, NT-proBNP levels in the cord blood of neonates with functional single ventricle were significantly higher than that in the cord blood of those with functional biventricles. Significant differences in the levels of NT-proBNP between survivors and nonsurvivors were observed within 1 year of birth. In this study, we found that the levels of NT-proBNP in the cord blood of neonates with CHD were higher than the levels in controls. This finding was striking in the group with right ventricular outflow tract obstruction, and it was associated with surgery for functional single ventricle and 1-year survival.

Comparison of invasive and non-invasive pressure gradients in aortic arch obstruction

BACKGROUND

Aortic arch obstruction can be evaluated by catheter peak-to-peak gradient or by Doppler peak instantaneous pressure gradient. Previous studies have shown moderate correlation in discrete coarctation, but few have assessed correlation in patients with more complex aortic reconstruction.

METHODS

We carried out retrospective comparison of cardiac catheterisations and pre- and post-catheterisation echocardiograms in 60 patients with native/recurrent coarctation or aortic reconstruction. Aortic arch obstruction was defined as peak-to-peak gradient ⩾25 mmHg in patients with native/recurrent coarctation and ⩾10 mmHg in aortic reconstruction.

RESULTS

Diastolic continuation of flow was not associated with aortic arch obstruction in either group. Doppler peak instantaneous pressure gradient, with and without the expanded Bernoulli equation, weakly correlated with peak-to-peak gradient even in patients with a normal cardiac index (r=0.36, p=0.016, and r=0.49, p=0.001, respectively). Receiver operating characteristic curve analysis identified an area under the curve of 0.61 for patients with all types of obstruction, with a cut-off point of 45 mmHg correctly classifying 64% of patients with arch obstruction (sensitivity 39%, specificity 89%). In patients with aortic arch reconstruction who had a cardiac index ⩾3 L/min/m², a cut-off point of 23 mmHg correctly classified 69% of patients (71% sensitivity, 50% specificity) with an area under the curve of 0.82.

CONCLUSION

The non-invasive assessment of aortic obstruction remains challenging. The greatest correlation of Doppler indices was noted in patients with aortic reconstruction and a normal cardiac index.

Exercise capacity in the Bidirectional Glenn physiology: Coupling cardiac index, ventricular function and oxygen extraction ratio

In Bi-directional Glenn (BDG) physiology, the superior systemic circulation and pulmonary circulation are in series. Consequently, only blood from the superior vena cava is oxygenated in the lungs. Oxygenated blood then travels to the ventricle where it is mixed with blood returning from the lower body. Therefore, incremental changes in oxygen extraction ratio (OER) could compromise exercise tolerance. In this study, the effect of exercise on the hemodynamic and ventricular performance of BDG physiology was investigated using clinical patient data as inputs for a lumped parameter model coupled with oxygenation equations. Changes in cardiac index, Qp/Qs, systemic pressure, oxygen extraction ratio and ventricular/vascular coupling ratio were calculated for three different exercise levels. The patient cohort (n=29) was sub-grouped by age and pulmonary vascular resistance (PVR) at rest. It was observed that the changes in exercise tolerance are significant in both comparisons, but most significant when sub-grouped by PVR at rest. Results showed that patients over 2 years old with high PVR are above or close to the upper tolerable limit of OER (0.32) at baseline. Patients with high PVR at rest had very poor exercise tolerance while patients with low PVR at rest could tolerate low exercise conditions. In general, ventricular function of SV patients is too poor to increase CI and fulfill exercise requirements. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different exercise levels according to patient specific data.

Decision-Making for Surgery in the Management of Patients with Univentricular Heart

A series of technical refinements over the past 30 years, in combination with advances in perioperative management, have resulted in dramatic improvements in the survival of patients with univentricular heart. While the goal of single-ventricle palliation remains unchanged - normalization of the pressure and volume loads on the systemic ventricle, the strategies to achieve that goal have become more diverse. Optimal palliation relies on a thorough understanding of the changing physiology over the first years of life and the risks and consequences of each palliative strategy. This review describes how to optimize surgical decision-making in univentricular patients based on a current understanding of anatomy, physiology, and surgical palliation.

Effect of high altitude exposure on the hemodynamics of the bidirectional Glenn physiology: modeling incremented pulmonary vascular resistance and heart rate

The considerable blood mixing in the bidirectional Glenn (BDG) physiology further limits the capacity of the single working ventricle to pump enough oxygenated blood to the circulatory system. This condition is exacerbated under severe conditions such as physical activity or high altitude. In this study, the effect of high altitude exposure on hemodynamics and ventricular function of the BDG physiology is investigated. For this purpose, a mathematical approach based on a lumped parameter model was developed to model the BDG circulation. Catheterization data from 39 BDG patients at stabilized oxygen conditions was used to determine baseline flows and pressures for the model. The effect of high altitude exposure was modeled by increasing the pulmonary vascular resistance (PVR) and heart rate (HR) in increments up to 80% and 40%, respectively. The resulting differences in vascular flows, pressures and ventricular function parameters were analyzed. By simultaneously increasing PVR and HR, significant changes (p <0.05) were observed in cardiac index (11% increase at an 80% PVR and 40% HR increase) and pulmonary flow (26% decrease at an 80% PVR and 40% HR increase). Significant increase in mean systemic pressure (9%) was observed at 80% PVR (40% HR) increase. The results show that the poor ventricular function fails to overcome the increased preload and implied low oxygenation in BDG patients at higher altitudes, especially for those with high baseline PVRs. The presented mathematical model provides a framework to estimate the hemodynamic performance of BDG patients at different PVR increments.

Laparoscopic antireflux surgery in infants with single ventricle physiology: a review

Laparoscopic fundoplication and gastrostomy tube placement have grown in popularity within the pediatric population for treatment of gastroesophageal reflux disease and failure to thrive, respectively. One population that has an increased need for gastric surgery in infancy is patients with congenital heart defects, especially those with "single ventricle physiology." The most common defect included in this population is hypoplastic left heart syndrome (HLHS). Because of the abnormal physiology present in this condition, there are concerns with regard to the use of laparoscopic procedures for gastric surgery in patients treated with a three-staged reconstruction. We review the staged reconstruction of infants with HLHS, address safety concerns of interstage noncardiac procedures on this patient population, and review the current literature regarding outcomes of laparoscopic gastric surgery on patients with single ventricle physiology.

Liver transplantation after stage II palliation for hypoplastic left heart syndrome

The association of biliary atresia (BA) with congenital heart diseases has been extensively described, and there are a number of reports on the outcomes of patients in this group who undergo liver transplantation (LT). The intraoperative management and the timing of LT for patients with end-stage liver disease are matters of debate, especially when complex heart diseases are involved. This report describes the outcome after LT for a pediatric recipient with BA and hypoplastic left heart syndrome. The patient underwent Norwood-Sano and Glenn procedures for heart palliation before LT. He was cyanotic, was severely malnourished, and had complications secondary to chronic liver failure. At the time of transplantation, the child was 16 months old and weighed 5175 g. Despite the critical clinical scenario and the long hospitalization period, there were no cardiac, vascular, or biliary complications after LT. At the age of 48 months, the patient was awaiting the final cardiac repair. In conclusion, the presence of complex cardiac malformations may not be a contraindication to LT. An experienced surgical team and a multidisciplinary approach are key to a successful outcome.

Resuscitation and perioperative management of the high-risk single ventricle patient: first-stage palliation

Infants born with hypoplastic left heart syndrome or other lesions resulting in a single right ventricle face the highest risk of mortality among all forms of congenital heart disease. Before the modern era of surgical palliation, these conditions were universally lethal; recent refinements in surgical technique and perioperative management have translated into dramatic improvements in survival. Nonetheless, these infants remain at a high risk of morbidity and mortality, and an appreciation of single ventricle physiology is fundamental to the care of these high-risk patients. Herein, resuscitation and perioperative management of infants with hypoplastic left heart syndrome are reviewed. Basic neonatal and pediatric life support recommendations are summarized, and perioperative first-stage clinical management strategies are reviewed.

Somatic growth in 94 single ventricle children -- comparing systemic right and left ventricle patients

AIM

We sought to compare and assess growth in single ventricle children with a systemic right or left ventricle in five time periods: at birth, before neonatal surgery, before the Glenn anastomosis and finally before and after the Fontan operation to 11 years of age.

METHODS

We reviewed medical records on 116 single ventricle patients operated at Rigshospitalet, Denmark from 1987 to 2007. Surgical procedures, feeding route, hemodynamic variables and anthropometric measurements such as weight and height were registered and converted to z-scores.

RESULTS

Ninety four single ventricle patients were included for analysis. Gestational age and birth weight was not significantly different between the left and right ventricle group. Before neonatal surgery and before the Glenn anastomosis, both groups showed equal growth retardation. However, a significant difference in catch-up growth was found before the Fontan operation. Thus, patients in the right ventricle group had a smaller median weight-for-age z-score compared with the left ventricle group in the pre-Fontan period (-1.9 and -1.6; p = 0.049) and in the post-Fontan period (-1.1 and -0.7; p = 0.034).

CONCLUSION

After the Glenn anastomosis single ventricle children with a systemic left ventricle have better weight gain compared with children with a systemic right ventricle.

Anaesthetic considerations in children with congenital heart disease undergoing non-cardiac surgery

The objective of this article is to provide an updated and comprehensive review on current perioperative anaesthetic management of paediatric patients with congenital heart disease (CHD) coming for non-cardiac surgery. Search of terms such as "anaesthetic management," "congenital heart disease" and "non-cardiac surgery" was carried out in KKH eLibrary, PubMed, Medline and Google, focussing on significant current randomised control trials, case reports, review articles and editorials. Issues on how to tailor perioperative anaesthetic management on cases with left to right shunt, right to left shunt and complex heart disease are discussed in this article. Furthermore, the author also highlights special considerations such as pulmonary hypertension, neonates with CHD coming for extracardiac surgery and the role of regional anaesthesia in children with CHD undergoing non-cardiac operation.

Perioperative management of infants undergoing fundoplication and gastrostomy after stage I palliation of hypoplastic left heart syndrome

Infants with hypoplastic left heart syndrome (HLHS) represent a high-risk population when they present for noncardiac surgery. To assist clinicians in the care of these infants, we present our experience of 36 HLHS patients who underwent abdominal surgery after stage I palliation. We reviewed patients with HLHS who underwent gastrostomy and/or fundoplication after stage I palliation during an 18-month period. We assessed the impact of preoperative echocardiographic predictors and regional anesthesia on use of intraoperative inotropes, extubation in the OR, perioperative instability, postoperative escalation of care, and length of hospital and intensive care unit stay. Of 39 abdominal operations, all but 2 were performed with open laparotomy. There was a positive association between regional anesthesia and instability during induction. Escalation of respiratory care occurred in 9 (23.1%) cases, and escalation of hemodynamic care occurred in 6 (15.4%) cases. Neoaortic valve insufficiency was associated with increased length of stay, and ventricular outflow obstruction was associated with escalation of hemodynamic care. Extubation in the OR was successful in 31 cases (79.5%). In-hospital death occurred in 1 patient (2.7%). HLHS infants often undergo abdominal surgery, but intraoperative instability and need for escalation of care is common. Specific echocardiographic findings were associated with length of stay and escalation of care. Regional anesthesia was associated with transient intraoperative instability but not with other adverse outcomes.

Contemporary management of pulmonary and systemic circulations after the Norwood procedure

Hypoplastic left heart syndrome remains one of the most challenging pathologies in pediatric cardiac surgery. The surgical techniques, and anesthetic and intensive care management, have evolved over the last decades, which has resulted in improved outcomes. A central component in the postoperative management of hypoplastic left heart syndrome patients is to achieve an optimal balance between the pulmonary and systemic circulations. This article discusses the contemporary postoperative management of pulmonary and systemic circulations in detail.