Congenital Cardiac Anesthesia Society
A Section of the the Society for Pediatric Anesthesia

{“questions”:{“r5ea7”:{“id”:”r5ea7″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Mackenzie Schumer, CAA AND Nicholas Houska, DO – University of Colorado, Children\u2019s Hospital Colorado\r\n\r\n\r\nA 15-year-old, 52 kg boy with Marfan\u2019s syndrome, aortic root dilation, and severe aortic regurgitation undergoes the Bentall procedure with a mechanical aortic valve replacement. The postoperative course is complicated by severe left ventricular dysfunction. Which of the following patient attributes is a contraindication for placement of an Impella\u00a9 5.5 left ventricular assist device?”,”desc”:”EXPLANATION \r\nThe Impella\u00ae is a short-term ventricular assist device (VAD) used to provide ventricular support in the setting of cardiogenic shock following acute myocardial infarction, acute transplant rejection, cardiac surgery, high-risk percutaneous coronary interventions or for the management of cardiomyopathy. The Impella\u00ae can be used in patients on extracorporeal membrane oxygenation (ECMO) for left ventricular unloading. The Impella 5.5\u00ae is also used as a bridge to heart transplantation. The Impella 5.5\u00ae is placed surgically via a direct transaortic approach or through right or left axillary artery cutdown and graft. It is placed within the left ventricle (LV), across the aortic valve, and utilizes a catheter-based microaxial pump to displace blood from the LV into the ascending aorta, providing up to 6 L\/ min of flow. Other iterations of the Impella\u00ae include the Impella CP\u00ae, which is placed percutaneously through the femoral artery and allows flows up to 4.3 L\/min, and the Impella RP\u00ae, which is used for right ventricular support and provides a flow rate of up to 4 L\/min. \r\n\r\nPlacement of an Impella 5.5\u00ae is contraindicated in patients with severe aortic stenosis or calcification with a valve area less than 0.6 cm^{2<\/sup>, LV thrombus, moderate or severe aortic insufficiency, presence of an atrial or ventricular septal defect, and presence of a mechanical aortic valve. Complications of the Impella\u00ae include damage to the aortic valve, ascending aorta, aortic root, and coronary sinuses, stroke, hemolysis, acute renal failure, and thrombocytopenia.\r\n\r\nThe Impella 5.5\u00ae can be used in the pediatric population if the patient can accommodate the 21 French (Fr) cannula that crosses the aortic valve. The device is 114 mm in length and is mounted on a 9 Fr catheter for implantation. While large studies do not exist in pediatric patients, there are published case reports of Impella\u00ae implantation in pediatric patients with most utilizing computed tomography or fluoroscopy for measurement and modeling of the aortic annulus, ascending aorta, aortic arch vessels, and LV cavity in conjunction with guided navigation for implantation. The Impella 5.5\u00ae and CP\u00ae have recently been approved by the U.S. Food and Drug Administration for use in pediatric patients weighing greater than or equal to 30 kg and greater than or equal to 52 kg respectively. However, the Impella\u00ae continues to be used off-label in smaller patients using vessel and LV size for guidance.\r\n \r\nThe patient described in this case underwent a Bentall procedure. In this case, he received a mechanical aortic valve which excludes him from Impella 5.5\u00ae implantation, making C. the correct answer. As discussed above, this patient\u2019s age and weight do not exclude Impella 5.5\u00ae use. However, measurements of the aortic valve annulus and aortic arch vessels, along with a three-dimensional rendering of LV size can help to determine if an Impella 5.5\u00ae catheter can be positioned appropriately in pediatric patients regardless of age or weight.\r\n\r\n\r\n \r\nREFERENCES \r\nAbiomed. Impella\u00ae 5.5 with SmartAssist\u00a9 instructions for use. https:\/\/d1edr79mp9g5zc.cloudfront.net\/5eb0affe-1991-449b-bfc0-a5a0516548bf\/cb8ef4bf-4fb9-46ed-91d7-6117f06bb18e\/cb8ef4bf-4fb9-46ed-91d7-6117f06bb18e_source__v.pdf . Accessed February 6, 2025. \r\n\r\nGlazier JJ, Kaki A. The Impella Device: Historical Background, Clinical Applications and Future Directions. Int J Angiol<\/em>. 2019;28(2):118-123. doi:10.1055\/s-0038-1676369\r\n\r\nOelkers B, Schumer E, Lambert AN, Alsoufi B, Kozik D, Wilkens SJ. The Use of Impella 5.5 Reduces Pulmonary Vascular Resistance as Bridge to Heart Transplant in a Pediatric Patient. ASAIO J<\/em>. 2025;71(3): e46-e47. doi:10.1097\/MAT.0000000000002256\r\n\r\nPediatric Cardiology. FDA Expands Indication for Impella Heart Pumps for Pediatric Patients. December 18, 2024. Accessed February 6, 2025.\r\nhttps:\/\/www.dicardiology.com\/content\/fda-expands-indication-impella-heart-pumps-pediatric-patients\r\n”,”hint”:””,”answers”:{“uccin”:{“id”:”uccin”,”image”:””,”imageId”:””,”title”:”A. Age”},”n3lsi”:{“id”:”n3lsi”,”image”:””,”imageId”:””,”title”:”B. Weight”},”hiqvf”:{“id”:”hiqvf”,”image”:””,”imageId”:””,”title”:”C. Mechanical aortic valve”,”isCorrect”:”1″}}}}}}

{“questions”:{“n56go”:{“id”:”n56go”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:”https:\/\/ccasociety.org\/wp-content\/uploads\/2025\/02\/CCAS-QOW-2-26-2025-Pic.png”,”imageId”:”8368″,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza, MD – Stollery Children\u2019s Hospital – Edmonton, CA \r\n\r\nA healthy ten-month-old, nine kg boy has just been weaned from cardiopulmonary bypass after repair of a ventricular septal defect. The results of a ROTEM performed after protamine administration are illustrated below. Which of the following treatments is MOST appropriate for hemostasis management in this patient?\r\n”,”desc”:”EXPLANATION \r\nThe neonatal hematologic system takes approximately one year to reach maturity. At birth, neonates have decreased platelet function, elevated von Willebrand factor concentration, lower levels of Factors II, VII, XI, X, XI, XII, pre-kallikrein, high-molecular-weight kallikrein, antithrombin, protein C, protein S, and decreased fibrinolytic activity. Overall, this results in a relative balance between pro-coagulants and anticoagulants. Therefore, neonates are at a high risk for both bleeding and thrombosis with any disruption in this delicate balance. Importantly, this risk is exacerbated in the setting of congenital heart disease and cardiac surgery with cardiopulmonary bypass (CPB). \r\n\r\nCPB exerts multiple adverse effects on hemostasis, increasing the risk of bleeding. Hemodilution causes a relative deficit of all coagulation factor proteins, particularly fibrinogen. Blood exposure to the CPB circuit induces an inflammatory reaction, triggering the coagulation cascade via contact activation that results in thrombin generation, hyperfibrinolysis, and platelet activation, necessitating anticoagulation during CPB. Additional factors that increase the risk of bleeding during pediatric cardiac surgery with CPB include the inherent need for anticoagulation with unfractionated heparin, the use of moderate to deep hypothermia, and the length and complexity of cardiac surgical procedures. As a result, neonates and infants undergoing cardiac surgery with CPB are highly likely to require large volumes of blood products to correct coagulopathy. \r\n\r\nDespite modern technological and pharmacological advances, management of hemostasis during pediatric cardiac surgery remains challenging. Viscoelastic testing (VET), including rotational thromboelastometry (ROTEM\u00ae), provides a comprehensive assessment of hemostasis at the point of care. ROTEM provides information on clot development from secondary hemostasis to clot lysis, including clot formation, clot firmness, and clot fibrinolysis. Basic ROTEM parameters include the following: 1) clotting time (CT), which is the time in seconds from the start of the test until significant levels (amplitude of 2 mm of clotting signal) of clot are detected; 2) the clot formation time (CFT), which is the time in seconds from the measurement of the CT until a fixed level of clot firmness (time between 2 mm and 20 mm amplitude of clotting signal); 3) the A10, which is the amplitude in mm of clotting signal 10 minutes after the CT; and 4) the maximal clot firmness (MCF), which describes the clot firmness and overall stability. Different assays are used in the ROTEM measurements, which target specific coagulation cascade components. The assays often used clinically include the INTEM, EXTEM, FIBTEM, and HEPTEM, which measure the intrinsic pathway, the extrinsic pathway, and the effect of fibrinogen and heparin, respectively. \r\n\r\nThese assays, as part of a transfusion algorithm, have been shown to decrease blood product transfusion and the incidence of major bleeding in adults. Data in the pediatric population is sparser and more equivocal. Faraoni et al. developed an algorithm to treat post-bypass coagulopathy in children using ROTEM. The authors found that the A10 on FIBTEM, as well as the CT and the A10 on EXTEM, were relevant parameters to guide hemostatic management. A prospective study by Naguib et al. studied the impact of using an institutional ROTEM-based transfusion algorithm on 28 infants and neonates. They found that patients in the ROTEM group received fewer overall platelet and cryoprecipitate transfusions than the control group and had higher hematocrit levels for the same amount of red blood cells transfused. In general, there is variability in the thresholds for transfusion of blood products and concentrates between institutions. Some of the published algorithms use the following: 1) a low A10 on FIBTEM to transfuse fibrinogen concentrate or cryoprecipitate; 2) a low A10 on EXTEM (with normal A10 on FIBTEM) to transfuse platelets; and 3) a prolonged CT on EXTEM to substitute clotting factors (i.e. factor concentrates or fresh frozen plasma). \r\n\r\nThe correct answer is A. The ROTEM illustrated above demonstrates a normal A10 and MCF on FIBTEM and a normal CT, A10, and MCF on EXTEM, suggesting normal hemostasis. Thus, this patient would not necessarily require any blood products, especially with no evidence of bleeding. However, it\u2019s important to remember that ROTEM is a tool to assess whole blood coagulation, and the decision to transfuse blood products or factor concentrates hinges on other factors including clinical context, surgical variables, and institutional practices. \r\n\r\n\r\n\r\n \r\nREFERENCES \r\n\r\nHartmann J, Hermelin D, Levy JH. Viscoelastic testing: An illustrated review of technology and clinical applications. ResPractThrombHaemost<\/em>. 2023;7:e100031. doi.org\/10.1016\/j.rpth.2022.100031\r\n\r\nDowney L and Faraoni D. Coagulation, Cardiopulmonary Bypass and Bleeding. In: Andropoulos DB, Mossad EB, Gottlieb EA, eds. Anesthesia for Congenital Heart Disease<\/em>. Fourth edition. John Wiley & Sons, Inc.; 2023: 377-400. \r\n\r\n\r\nNaguib AN, Carrillo SA, Corridore M, et al. A ROTEM-guided algorithm aimed to reduce blood product utilization during neonatal and infant cardiac surgery. J Extra Corpor Technol<\/em>. 2023;55(2):60-69. doi:10.1051\/ject\/2023017\r\n\r\n\r\nFaraoni D, Willems A, Romlin BS, Belisle S, Van der Linden P. Development of a specific algorithm to guide haemostatic therapy in children undergoing cardiac surgery: a single-centre retrospective study. Eur J Anaesthesiol<\/em>. 2015;32(5):320-329. doi:10.1097\/EJA.0000000000000179\r\n”,”hint”:””,”answers”:{“fw3vd”:{“id”:”fw3vd”,”image”:””,”imageId”:””,”title”:”A.\tNo intervention”,”isCorrect”:”1″},”z6ms3″:{“id”:”z6ms3″,”image”:””,”imageId”:””,”title”:”B.\tPlatelet transfusion”},”tok4y”:{“id”:”tok4y”,”image”:””,”imageId”:””,”title”:”C.\tFibrinogen concentrate administration”}}}}}

{“questions”:{“ev9ue”:{“id”:”ev9ue”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza, MD – Stollery Children\u2019s Hospital – University of Alberta – Edmonton Canada \r\n\r\nA 2.2 kg boy with hypoplastic left heart syndrome is born at 34 weeks of gestation. A decrease in which of the following mortality outcomes is MOST likely if this patient undergoes a Stage I Hybrid versus a Stage I Norwood palliation? “,”desc”:”EXPLANATION \r\nHypoplastic left heart syndrome (HLHS) is associated with significant morbidity and mortality as compared to other forms of congenital heart disease. HLHS is typically palliated with a series of three surgical procedures but may also be treated with cardiac transplantation. The Stage 1 Norwood was first described in 1979 and is comprised of a Damus-Kaye-Stansel (DKS) anastomosis to provide systemic blood flow, a systemic-to-pulmonary shunt to provide pulmonary blood flow, ascending aorta and aortic arch reconstruction, and an atrial septectomy to provide unrestricted flow of pulmonary venous blood to the right atrium and right ventricle. It remains associated with an interstage mortality of 10-15%, as parallel circulation results in a labile ratio of pulmonary to systemic blood flow with an increased risk of coronary ischemia. The Stage I Hybrid palliation (HP) was developed as an alternative to the Stage I Norwood to avoid cardiopulmonary bypass (CPB) in neonates at a higher risk for morbidity and mortality. While the specifics of the procedure vary amongst congenital cardiac surgical programs, it is typically approached via median sternotomy and consists of placement of bilateral pulmonary artery (PA) bands to restrict pulmonary blood flow and a patent ductus arteriosus stent to supply systemic blood flow, with or without stenting or balloon septostomy of the atrial septum. \r\n\r\nThere remains considerable practice variability concerning indications and execution of the Stage I HP amongst various congenital cardiac surgical programs, making comparisons of outcomes challenging. Zanaboni et al. surveyed 54 centers in North America, resulting in a 50% response rate. The majority of respondents use the Stage I HP for neonates deemed to be \u201chigh risk\u201d. Two centers use the Stage I HP for all single ventricle patients. The most common determinants of \u201chigh risk\u201d were prematurity, low birth weight, reduced ventricular dysfunction, severe tricuspid regurgitation, and additional cardiac or non-cardiac anomalies. Procedural techniques varied, with 95% using bilateral Gore-tex PA bands, 67% using ductal stents versus a prostaglandin infusion, and 23% routinely performing atrial septal enlargement. Interstage management was variable, with some centers opting for the Stage I Norwood at a time point four to six weeks after the Stage I HP and others opting for a comprehensive Stage II bidirectional Glenn at a time point five to six months later.\r\n\r\nA 2024 meta-analysis by Iskander et al. analyzed 21 studies, including 1,182 patients with HLHS. The authors compared mortality and morbidity in patients who underwent the Stage I Norwood procedure to those who underwent the Stage I HP. They found no difference in in-hospital mortality or transplantation rate. Further, the authors found a statistically significant difference in one-year mortality (43.99% for the Stage I Hybrid vs 30.72% for the Stage I Norwood), which did not persist at three or five years. Five studies that specifically evaluated \u201chigh-risk\u201d patients found an in-hospital mortality and\/or transplantation rate of 19.5% for the Stage I Hybrid vs 35.59% for the Stage I Norwood group. The most common \u201chigh risk\” factors included prematurity, other cardiac anomalies such as intact atrial septum and tricuspid valve insufficiency, and genetic or other non-cardiac anomalies. Nonetheless, the decrease in in-hospital mortality in the Stage I HP group did not translate into an interstage survival benefit (interstage mortality rate of 23.7% for Stage I HP vs 14.06% for Stage I Norwood). Interestingly, the Stage I HP patients experienced a higher rate of unplanned reinterventions, were less likely to reach stage II and III palliations, and had longer ICU and hospital length-of-stay. This likely reflects the fact that patients undergoing Stage I HP typically present with the above-mentioned risk factors and require a more extensive stage II palliation. \r\n\r\nThe correct answer is B. With the current available data, decreased in-hospital mortality in high-risk patients after the Stage I HP is the most likely benefit. Stage I Norwood patients had increased survival rates in the interstage period and at one year. However, it remains important to consider these conclusions in light of the fact that the hybrid procedure is most often performed in high-risk patients with a greater likelihood of morbidity and mortality. There is also considerable variation in procedural factors between congenital cardiac programs, which may impact outcomes, making direct comparisons of the two strategies susceptible to statistical error. \r\n\r\n\r\n\r\n \r\nREFERENCES \r\nDiaz-Berenstain L, Abbasi RK, Riegger LO, Steven JM, Nicolson SC, Andropoulos DB. Anesthesia for the Patient with a Single Ventricle. In: Andropoulos DB, Mossad EB, Gottlieb EA, eds. Anesthesia for Congenital Heart Disease<\/em>. 4th edition. John Wiley & Sons, Inc.; 2023: 744-746.\r\n\r\nIskander C, Nwankwo U, Kumanan KK, et al. Comparison of Morbidity and Mortality Outcomes between Hybrid Palliation and Norwood Palliation Procedures for Hypoplastic Left Heart Syndrome: Meta-Analysis and Systematic Review. J Clin Med<\/em>. 2024;13(14):4244. doi:10.3390\/jcm13144244\r\n\r\nZanaboni DB, Sower CT, Yu S, Lowery R, Romano JC, Zampi JD. Practice variation using the hybrid stage I procedure in congenital heart disease: Results from a national survey. JTCVS Open<\/em>. 2024;21:248-256. doi:10.1016\/j.xjon.2024.07.020\r\n”,”hint”:””,”answers”:{“o4yeu”:{“id”:”o4yeu”,”image”:””,”imageId”:””,”title”:”A.\tInterstage mortality”},”f4p37″:{“id”:”f4p37″,”image”:””,”imageId”:””,”title”:”B.\tIn-hospital mortality “,”isCorrect”:”1″},”7mm4l”:{“id”:”7mm4l”,”image”:””,”imageId”:””,”title”:”C.\tOne-year mortality\r\n\r\n”}}}}}

{“questions”:{“hf9oe”:{“id”:”hf9oe”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza, MD – Stollery Children\u2019s Hospital – Edmonton Canada \r\nA 3.8 kg, 4-day-old term girl presents with pulmonary edema and lactate of 3. Transthoracic echocardiography demonstrates a type B interrupted aortic arch, posterior malalignment ventricular septal defect, and severe left-ventricular outflow tract obstruction. Which of the following procedures is the MOST appropriate surgical strategy to correct this defect? \r\n”,”desc”:”EXPLANATION \r\nInterrupted aortic arch (IAA) has an incidence of 1% of all congenital heart disease. It is classified into the following subtypes: 1) Type A (interruption distal to left subclavian artery); 2) Type B (interruption between left common carotid and left subclavian arteries); and 3) Type C (interruption between the innominate and left common carotid arteries). IAA is commonly associated with other congenital cardiac anomalies, including ventricular septal defect (VSD), which may contribute to left-ventricular outflow tract obstruction (LVOTO), as well as aortic annular hypoplasia, bicuspid aortic valve, and left ventricular (LV) muscle bundles. Type B IAA is commonly associated with a posterior malalignment VSD and an aberrant right subclavian artery. The posterior malalignment VSD can contribute to LVOTO with deviation of the conal septum. Neonates born with IAA typically remain asymptomatic until the ductus arteriosus closes, resulting in decreased lower body perfusion and, eventually, congestive heart failure and cardiogenic shock. \r\n\r\n\r\nThere are several surgical options available for the repair of IAA. In contemporary practice, primary complete neonatal repair has become standard of care. In children without LVOTO, repair typically consists of aortic arch repair with VSD closure. In low-birthweight or premature children, as well as those with contra-indications to CPB, palliative options include pulmonary artery banding along with either PDA stenting in the catheterization laboratory or off-bypass arch repair via thoracotomy. However, in the setting of significant LVOTO, management remains challenging with technically difficult procedures and a high rate of reintervention. Surgical options for this group of patients include the following: (1) aortic arch repair, VSD closure, and conal muscle resection; (2) initial neonatal Norwood or hybrid palliation with staged, biventricular repair in later infancy or (3) a neonatal Ross-Konno. In some patients with severe LVOTO, these procedures have a high probability of significant residual LVOTO, and an alternative approach for consideration is the Yasui procedure. It was first published in 1987 and consists of a Damus-Kaye-Stansel anastomois, baffled VSD closure that incorporates the native pulmonary valve, and a right ventricle to pulmonary artery conduit. \r\n\r\n\r\nGreene et al. reported a single institution\u2019s experience with the Yasui procedure at Boston Children\u2019s Hospital, including 25 cases over 32 years. They reported a survival rate of 91% at 5 years; freedom from LVOT reintervention was 91% and freedom from RV-PA conduit reintervention was 52%. All patients had normal biventricular function. The authors concluded that the Yasui procedure compared favorably to the Staged single ventricle palliative pathway and the Ross-Konno procedure in terms of mortality and LVOT reintervention. Furthermore, patients who underwent the Yasui procedure did not require a greater number of reinterventions overall. \r\n\r\n \r\nA multicenter study by Luo et al. analyzed outcomes in 150 neonates with IAA. They found that patients undergoing a Ross-Konno or a Yasui procedure had a lower <\/em> risk of LVOT reintervention compared to standard arch repair, especially when combined with conal resection. Mortality after the Yasui procedure was seven percent, but most of those children had undergone a two-stage Yasui, with an interstage period characterized by single-ventricle physiology with a shunt. Interestingly, the mortality rate in children undergoing a Ross-Konno procedure was 0%. The authors attributed this mortality rate to patient selection, as children with IAA and LVOTO are more likely to have normal LV and mitral valve size and function as compared to patients with critical aortic stenosis and hypoplastic LV. Children who underwent IAA repair with VSD closure without conal resection had similar rates of LVOT reintervention as those with the Yasui procedure, but the authors noted that those children were less likely to have severe LVOTO. While most centers favor a single-stage neonatal repair whenever possible, the hybrid procedure, consisting of bilateral PA banding and ductal stenting, has been gaining traction. This approach is typically reserved for high-risk neonates, including those with prematurity, low birth weight, genetic disorders, extra-cardiac malformations, or clinical conditions such as sepsis, necrotizing enterocolitis, or intracranial hemorrhage. Conversely, some centers successfully use the hybrid approach in the absence of the listed risk factors.\r\n\r\n\r\nThe correct answer among those choices is B, the Yasui procedure, consisting of a complete repair and relief of LVOTO. Aortic arch repair with VSD closure remains the standard operation for IAA with a VSD, but is likely to require reintervention, especially in children with pre-existing LVOTO. The patient described in the stem also has severe LVOTO and would likely require conal muscle resection in addition to aortic arch repair and VSD closure. PA banding with off-bypass aortic arch repair is typically reserved for children with high-risk features or contraindications to cardiopulmonary bypass, which are not present in the patient in the stem. It is important to note that IAA remains a heterogeneous disease, and management requires multidisciplinary planning tailored to each patient and each surgical program\u2019s expertise.\r\n\r\n\r\n\r\n\r\n\r\n \r\nREFERENCES \r\n\r\nLaPar DJ, Baird CW. Surgical Considerations in Interrupted Aortic Arch. Semin Cardiothorac Vasc Anesth<\/em>. 2018;22(3):278-284. doi:10.1177\/1089253218776664\r\n\r\nGreene CL, Scully B, Staffa SJ, et al. The Yasui operation: A single institutional experience over 30 years. JTCVS Open<\/em>. 2023;15:361-367. Published 2023 Jul 18. doi:10.1016\/j.xjon.2023.06.019\r\n\r\n\r\nLuo S, Schoof PH, Hickey E, et al. The Fate of the Left Ventricular Outflow Tract Following Interrupted Aortic Arch Repair. World J Pediatr Congenit Heart Surg<\/em>. 2024;15(5):562-570. doi:10.1177\/21501351241236742\r\n\r\n\r\nAlsoufi B. Hybrid First-stage Palliation and Other Strategies to Achieve Biventricular Repair in High-Risk Neonates With Complex Heart Anomalies and Aortic Arch Obstruction. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu<\/em>. 2023;26:40-49. doi:10.1053\/j.pcsu.2022.12.009\r\n\r\n\r\nYasui H, Kado H, Nakano E et al. Primary repair of interrupted aortic arch and severe aortic stenosis in neonates. J Thorac Cardiovasc Surg<\/em>. 1987; 93:539-545.\r\n”,”hint”:””,”answers”:{“1kmuq”:{“id”:”1kmuq”,”image”:””,”imageId”:””,”title”:”A)\tAortic arch reconstruction and ventricular septal defect repair”},”j8idw”:{“id”:”j8idw”,”image”:””,”imageId”:””,”title”:”B)\tYasui procedure”,”isCorrect”:”1″},”kig6l”:{“id”:”kig6l”,”image”:””,”imageId”:””,”title”:”C)\tPulmonary artery banding with off-bypass arch repair\r\n\r\n”}}}}}

{“questions”:{“mfzs3”:{“id”:”mfzs3″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Melissa Colizza, MD, Stollery Children\u2019s Hospital, Edmonton, Canada \r\n\r\nA 25-year-old, G1P0 woman with tricuspid atresia palliated with the Fontan procedure presents in active labor at 33 weeks of gestation. Her most recent cardiology evaluation demonstrated stable single ventricular function. Which of the following cardiovascular complications is MOST likely during her hospitalization?”,”desc”:”EXPLANATION \r\nThe Fontan procedure is the final operation in the single ventricle palliative pathway. Fontan physiology is characterized by the absence of a subpulmonary ventricle and drainage of systemic venous blood directly into the pulmonary arterial circulation, resulting in passive blood return to the lungs for oxygenation. With surgical and perioperative advancements, Fontan patients are reaching reproductive age due to an estimated survival rate nearing 80% at 20 years. However, morbidity remains high as a result of the deleterious consequences of Fontan physiology, such as elevated systemic vascular resistance (SVR), high arrhythmia burden, single ventricular diastolic dysfunction, chronic elevation in central venous pressure (CVP), and reduced preload\/filling of the single ventricle from the cavo-pulmonary anastomosis. Additionally, Fontan physiology is characterized by low cardiac output despite higher central venous pressures, high pulmonary vascular resistance, and increased preload dependence. The physiologic effects of pregnancy, positive pressure ventilation and sustained arrhythmias can lead to negative hemodynamic effects.\r\n\r\nDuring pregnancy, neurohormonal activation causes increased heart rate, blood volume, cardiac output, as well as vasodilation to favor uteroplacental perfusion. These factors add considerable hemodynamic stress to patients with Fontan physiology, who may already have tenuous cardiopulmonary function\/reserve. The pregnancy-induced decrease in SVR may not completely offset the intrinsic arterial stiffness present in Fontan patients, thereby increasing the work required from the single ventricle to meet the new metabolic requirements. The 45% increase in blood volume is usually well tolerated and contributes to increased cardiac output. The expansion in blood volume load typically reaches a maximum during labor, delivery, and the early post-partum period due to autotransfusion from uterine contractions and subsequent uterine involution. \r\n\r\nHowever, in some patients with elevated pulmonary vascular resistance (PVR), cavo-pulmonary pathway obstruction\/stenosis, valvular regurgitation, or diastolic dysfunction, the expansion in blood volume may precipitate heart failure (HF). Garcia Romero et al. conducted a systematic review to evaluate maternal and fetal outcomes in pregnant Fontan patients. The study analyzed outcomes in 225 pregnancies in 133 women that resulted in 115 live births. Supraventricular tachyarrhythmia was the most common adverse event affecting 8.4% (3% to 37%) of Fontan patients. The underlying mechanism is attributed to pregnancy-induced adrenergic activation and atrial stretch from fluid loading in individuals prone to tachyarrhythmias. Heart failure was the second most common complication affecting 3.9% (3% to 11%) of the pregnant Fontan patients. The low occurrence of heart failure is explained by the low rate of systolic ventricular failure and low incidence of severe Fontan-related complications in those Fontan patients who are able to get pregnant. Reassuringly, no maternal deaths were reported in this analysis. Whilst the Fontan circulation creates a prothrombotic state, exacerbated during pregnancy, thromboembolic events such as strokes and pulmonary embolism were infrequent in the study population. \r\n\r\nObstetric complications are common in the Fontan population. Both antepartum and post-partum bleeding are estimated to occur in roughly 15% of pregnant Fontan patients, compared to 2-11% in the general population. This is attributed to underlying liver disease, anticoagulation, a higher incidence of cesarian section delivery, and the restrictive use of uterotonics. Interestingly, Fontan patients without significant liver disease and higher resting saturation were more likely to become pregnant. Over 50% of Fontan patients who become pregnant experience miscarriages. Furthermore, 50% of live births occur prematurely, and 20% of these neonates are small for gestational age. These complications are thought to be caused by a chronically low cardiac output state and neuro-hormonal activation, leading to uteroplacental insufficiency. \r\n\r\nThe literature suggests many single-ventricle patients can safely carry a pregnancy close to term. According to the modified WHO classification of maternal cardiovascular risk, Fontan patients who do not have protein-losing enteropathy, systolic ventricular dysfunction, or atrioventricular valve regurgitation are considered to be at moderate-to-high risk of adverse cardiac or obstetric events (Class III) whereas those who do have the complications listed above are at extremely high risk (class IV). \r\n\r\nThe correct answer is C, arrhythmias, which occur more frequently than heart failure or thromboembolic events in pregnant Fontan patients with few other comorbidities.\r\n\r\n\r\n \r\nREFERENCES \r\nGarcia Ropero A, Baskar S, Roos Hesselink JW, et al. Pregnancy in Women With a Fontan Circulation: A Systematic Review of the Literature. Circ Cardiovasc Qual Outcomes<\/em>. 2018;11(5):e004575. doi:10.1161\/CIRCOUTCOMES.117.004575\r\n\r\nMaisat W, Yuki K. The Fontan Circulation in Pregnancy: Hemodynamic Challenges and Anesthetic Considerations. J Cardiothorac Vasc Anesth<\/em>. 2024;38(11):2770-2782. doi:10.1053\/j.jvca.2024.07.021\r\n\r\nBreviario S, Krishnathasan K, Dimopoulos K, et al. Pregnancy in women with a Fontan circulation: Short and long-term outcomes. Int J Cardiol<\/em>. 2024;415:132445. doi:10.1016\/j.ijcard.2024.132445\r\n\r\nvan Hagen IM, Roos-Hesselink JW. Pregnancy in congenital heart disease: risk prediction and counselling. Heart<\/em>. 2020;106(23):1853-1861. doi:10.1136\/heartjnl-2019-314702\r\n\r\nCannobio MM, Warnes CA, Aboulhosn J et al. Management of pregnancy in patients with complex congenital heart disease: A scientific statement for healthcare professionals from the American Heart Association. Circulation<\/em>. 2017;135(8):e50-e87. doi:10.1161\/CIR.0000000000000458\r\n”,”hint”:””,”answers”:{“q6p2y”:{“id”:”q6p2y”,”image”:””,”imageId”:””,”title”:”A.\tHeart failure”},”kfvdd”:{“id”:”kfvdd”,”image”:””,”imageId”:””,”title”:”B.\tPulmonary embolism”},”h8eyb”:{“id”:”h8eyb”,”image”:””,”imageId”:””,”title”:”C.\tArrhythmias”,”isCorrect”:”1″}}}}}