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

{“questions”:{“jbe99”:{“id”:”jbe99″,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Meera Gangadharan, MD, FASA, FAAP – University of Texas at Houston, McGovern Medical School, Children\u2019s Memorial Hermann Hospital \r\n\r\nA 3-week-old boy is admitted to the cardiac intensive care unit with acute congestive heart failure and generalized hypotonia. Transthoracic echocardiography demonstrates a dilated left ventricle with severely diminished function. Additionally, an ECG indicates a prolonged QTc interval, and a complete blood count is significant for neutropenia. Which of the following X-linked conditions is MOST likely to be present in this patient? \r\n”,”desc”:”EXPLANATION \r\nBarth syndrome is an X-linked recessive condition that classically presents with cardiomyopathy, poor growth, neutropenia, small stature, and skeletal myopathy. It is a rare condition currently estimated to affect one in a million males worldwide. Due to its X-linked recessive classification, it almost exclusively affects males. Neutropenia may be cyclical, intermittent, or sustained and increases the risk of bacterial infections, the second most common cause of death after cardiomyopathy. Skeletal myopathy is usually non-progressive and typically affects the proximal limb muscles. \r\n\r\n\r\nPatients commonly present during infancy with signs and symptoms of acute dilated cardiomyopathy. In male fetuses, hydrops fetalis, cardiomyopathy, and intrauterine growth fetuses are also typical of Barth syndrome. Often there is a family history of multi-generational fetal loss and\/or still births of males. Often, a viral illness is the precipitating event that brings an infant to the hospital with symptoms of heart failure, making the diagnosis of Barth syndrome less obvious. Though dilated cardiomyopathy is the most common cardiac condition seen in young infants and children with Barth Syndrome, hypertrophic, restrictive, and left ventricular non-compaction cardiomyopathy may also be present in some. Patients with Barth syndrome are also at risk for ventricular arrhythmias and sudden death. A prolonged QTc interval on an electrocardiogram is evident in 25%-75% of patients. Infancy and early childhood are periods of high risk for cardiac death. Older children appear to have more stable cardiac function.\r\n\r\n\r\nBarth syndrome is caused by a genetic defect in the TAFAZZIN gene, located on chromosome Xq28, which encodes an enzyme involved in cardiolipin remodeling. Cardiolipin (CL) is a phospholipid present on the inner mitochondrial membrane that is essential for important functions of the respiratory chain. As a result of the genetic defect, abnormal enzyme activity results in an accumulation of monolysocardiolipin (MCL). An elevation in the MCL:CL ratio is thus present in the blood and tissues of patients with Barth syndrome. An elevated MCL:CL ratio approaches 100% sensitivity and specificity for Barth syndrome. Patients are thus at increased risk of lactic acidosis and hypoglycemia due to mitochondrial dysfunction.\r\n\r\n\r\nManagement of heart failure in Barth Syndrome follows standard guidelines. Transplant is a viable option for end-stage heart failure. Morbidity and mortality after cardiac transplantation is equivalent in Barth syndrome and non-Barth syndrome patients with dilated cardiomyopathy. Skeletal muscle myopathy is generally managed with physical therapy, exercise regimens and devices to aid mobility. Although there are no currently available therapies for Barth Syndrome, elamipretide is a medication that is being reviewed by the Food and Drug Administration to treat Barth syndrome. This peptide molecule localizes to the inner mitochondrial membrane and enhances ATP synthesis.\r\n\r\n\r\nThe pre-anesthetic evaluation of patients with Barth syndrome should include a complete blood count, glucose, and carnitine levels. A recent electrocardiogram and echocardiogram should be reviewed prior to surgery. Excessive preoperative fasting should also be avoided due to the risk of hypoglycemia and lactic acidosis. Succinylcholine is contraindicated due to skeletal myopathy. Cardiac medications should be managed as for any other patient and the usual precautions should be taken if a rhythm management device is present. Sterility, aseptic technique and prophylactic antibiotics are especially important in neutropenic patients. Postoperative ventilation may be necessary for patients with significant skeletal muscle weakness. \r\n\r\n\r\nChoice A is the correct answer due to the presentation of cardiomyopathy, hypotonia, prolonged QTc, and neutropenia, all features of Barth syndrome. Alport syndrome is a condition in which there is hearing loss and renal disease. The only cardiovascular manifestation is hypertension, secondary to renal disease. X-linked dominant, autosomal dominant and autosomal recessive forms have been described. Thrombocytopenia is associated with Alport syndrome, versus the neutropenia that is associated with Barth syndrome. Duchenne muscular dystrophy is an X-linked recessive disorder with cardiomyopathy, skeletal myopathy, and smooth muscle myopathy. Cardiac failure usually occurs later during this disease and is very unlikely to manifest in infancy as demonstrated in the stem.\r\n\r\n\r\n\r\n \r\nREFERENCES \r\n\r\nTaylor C, Rao ES, Pierre G, et al. Clinical presentation and natural history of Barth Syndrome: An overview. J Inherit Metab Dis<\/em>. 2022;45(1):7-16. doi:10.1002\/jimd.12422\r\n\r\n\r\nThompson R, Jeffries J, Wang S, et al. Current and future treatment approaches for Barth syndrome. J Inherit Metab Dis<\/em>. 2022; 45(1):17-28. doi: 10.1002\/jimd.12453.\r\n\r\n\r\nLi Y, Godown J, Taylor CL, Dipchand AI, Bowen VM, Feingold B. Favorable outcomes after heart transplantation in Barth syndrome. J Heart Lung Transplant<\/em>. 2021; 40(10):1191-1198. doi: 10.1016\/j.healun.2021.06.017.\r\n\r\n\r\nBaum VC, O\u2019Flaherty JE. Barth syndrome. In: Baum VC, O\u2019Flaherty JE, eds. Anesthesia for Genetic, Metabolic and Dysmorphic Syndromes of Childhood<\/em>. 3rd ed. Philadelphia, PA: Wolters Kluwer; 2015:50-51.\r\n\r\n\r\nBaum VC, O\u2019Flaherty JE. Alport syndrome. In: Baum VC, O\u2019Flaherty JE, eds. Anesthesia for Genetic, Metabolic and Dysmorphic Syndromes of Childhood<\/em>. 3rd ed. Philadelphia, PA: Wolters Kluwer; 2015:28-29.\r\n\r\n\r\nBaum VC, O\u2019Flaherty JE. Duchenne muscular dystrophy. In: Baum VC, O\u2019Flaherty JE, eds. Anesthesia for Genetic, Metabolic and Dysmorphic Syndromes of Childhood<\/em>. 3rd ed. Philadelphia, PA: Wolters Kluwer; 2015:125-127.\r\n”,”hint”:””,”answers”:{“rb34e”:{“id”:”rb34e”,”image”:””,”imageId”:””,”title”:”A.\tBarth Syndrome”,”isCorrect”:”1″},”f5yvq”:{“id”:”f5yvq”,”image”:””,”imageId”:””,”title”:”B.\tAlport Syndrome”},”l3buy”:{“id”:”l3buy”,”image”:””,”imageId”:””,”title”:”C.\tDuchenne muscular dystrophy”}}}}}

{“questions”:{“g4glk”:{“id”:”g4glk”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Meera Gangadharan, MD, FASA, FAAP – University of Texas at Houston, McGovern Medical School, Children\u2019s Memorial Hermann Hospital \r\nA 6-year-old girl with a history of orthotopic heart transplantation two years prior is undergoing routine cardiac catheterization and endomyocardial biopsy. After induction of anesthesia, the patient develops a regular, narrow-complex supraventricular tachycardia with a rate of 200 bpm and blood pressure of 85\/43. Which of the following modifications in the dose of adenosine is MOST appropriate to treat this patient?”,”desc”:”EXPLANATION \r\nThe cardiac allograft demonstrates altered physiology due to denervation of the autonomic nervous system. Parasympathetic innervation is lost making the resting heart rate slightly higher than normal. Holter studies have demonstrated higher minimum heart rates, similar maximal heart rates, and decreased heart rate variability in patients after heart transplantation. Because of the loss of the baroreceptor reflex, the transplanted heart does not make rapid compensatory adjustments in heart rate. The transplanted heart has been described as \u201cpreload dependent\u201d because it relies on Frank-Starling forces and end-diastolic volume to maintain cardiac output in the absence of the ability to alter the heart rate rapidly. Conversely, the intrinsic properties of the cardiac muscle are preserved.\r\n\r\n\r\nAdenosine, a drug commonly used to treat supraventricular tachycardia (SVT), is a purine nucleoside that binds to G protein coupled receptors in the heart. In the sinus node, activation of these receptors decreases the rate of spontaneous depolarization by reducing intracellular cyclic AMP levels, leading to a decreased heart rate. In the atrioventricular (AV) node, activation of these receptors results in the inhibition of L-type calcium channels, which in turn decreases conduction velocity and leads to AV block. \r\n\r\n\r\nThe sinus node and AV node of the transplanted heart are hypersensitive to the pharmacologic effects of adenosine as compared to the native, non-transplanted heart. A 1990 study by Ellenbogen et al demonstrated that the sinus node and the AV node in patients who had undergone heart transplantation exhibited an exaggerated response to adenosine administration. Twenty-eight heart transplant patients and nine patients without heart transplantation were administered increasing doses of adenosine during an electrophysiology study. The study demonstrated that the sinus node cycle length was significantly greater and the duration of the chronotropic effect of adenosine was prolonged in the heart transplant patients. Similar results were demonstrated in the AV node. \r\n\r\n\r\nIn a small series of patients undergoing pharmacologic stress testing with adenosine, Toft et al demonstrated that 4% of non-transplanted heart patients developed AV block during the test. Based on this study and others, the administration of adenosine to cardiac transplant recipients is often considered a relative contraindication due to the possibility of prolonged heart block. However, more recent evidence suggests that this caution may have been overstated.\r\n\r\n\r\nA single-center, prospective study by Flyer et al (2017) investigated the pharmacologic effects of adenosine in stable heart transplant patients who were undergoing cardiac catheterization. Electrophysiological measurements were taken during the administration of increasing doses of adenosine in eighty patients between the ages of six months and 25 years. Adenosine dosing was initiated at 12.5 mcg\/kg and increased to 25mcg\/kg, 50mcg\/kg, 100mcg\/kg and 200mcg\/kg. Patients over sixty kilograms received 0.8 mg, 1.5 mg, 3 mg, 6 mg, and 12 mg of adenosine incrementally. Dose escalation was stopped when AV block or clinically significant asystole occurred (i.e. sinus pause or AV block greater than twelve seconds). The results indicated that a dose of 12.5 mcg\/kg did not cause AV block in any patient. Twelve percent developed AV block after a dose of 25mcg\/kg, 31% after 50 mcg\/kg, 72% after 100 mcg\/kg, and 96% after 200mcg\/kg. None of the patients needed rescue pacing after adenosine administration. The mean duration of adenosine effect was 4.3 seconds, and the longest duration was 8.4 seconds. There was no association between the dose of adenosine needed to produce AV block and the time from the heart transplant. The authors concluded that adenosine is safe and efficacious in the stable heart transplant population. They suggested that the initial adenosine dose should be 25 mcg\/kg, which is a quarter of the dose recommended in the PALS and ACLS algorithms to treat supraventricular tachycardia. If the desired effect is not achieved, the dose should be increased gradually. \r\n\r\n\r\nFor the patient in the stem, the initial dose of adenosine used to treat supraventricular tachycardia should be decreased. The 2023 International Society of Heart and Lung Transplantation (ISHLT) guideline for the care of heart transplant recipients recommends an initial dose of 25 mcg\/kg (or 1.5 mg in patients over 60 kg) in conjunction with a gradual dose increase until the desired clinical response is achieved for administration of the drug adenosine.\r\n\r\n\r\n\r\n \r\nREFERENCES \r\n\r\nKleiman Z, Zabala LM. Post orthotopic cardiac transplantation. In: Berenstain LK, Spaeth JP (Eds). Congenital Cardiac Anesthesia: A Case-Based Approach<\/em>. Cambridge University Press, Cambridge, UK; 2021. 290-298.\r\n\r\n\r\n\r\nToft J, Mortensen J, Hesse B. Risk of atrioventricular block during adenosine pharmacologic stress testing in heart transplant recipients. Am J Cardiol<\/em>. 1998;82(5):696-697, A9. doi:10.1016\/s0002-9149(98)00392-0\r\n\r\n\r\nEllenbogen KA, Thames MD, DiMarco JP, Sheehan H, Lerman BB. Electrophysiological effects of adenosine in the transplanted human heart. Evidence of super sensitivity. Circulation<\/em>. 1990;81(3):821-828. doi:10.1161\/01.cir.81.3.821\r\n\r\n\r\nFlyer JN, Zuckerman WA, Richmond ME, et al. Prospective Study of Adenosine on Atrioventricular Nodal Conduction in Pediatric and Young Adult Patients After Heart Transplantation. Circulation<\/em>. 2017;135(25):2485-2493. doi:10.1161\/CIRCULATIONAHA.117.028087\r\n\r\n\r\nVelleca A, Shullo MA, Dhital K, et al. The International Society for Heart and Lung Transplantation (ISHLT) guidelines for the care of heart transplant recipients. J Heart Lung Transplant<\/em>. 2023; 42(5): e1-e141. doi.org\/10.1016\/j.healun.2022.10.015\r\n\r\n”,”hint”:””,”answers”:{“iknc0”:{“id”:”iknc0″,”image”:””,”imageId”:””,”title”:”A)\tIncrease”},”m5sec”:{“id”:”m5sec”,”image”:””,”imageId”:””,”title”:”B)\tDecrease”,”isCorrect”:”1″},”mzhfp”:{“id”:”mzhfp”,”image”:””,”imageId”:””,”title”:”C)\tNo change”}}}}}

{“questions”:{“ifojw”:{“id”:”ifojw”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Meera Gangadharan, MBBS, FAAP, FASA – University of Texas Health Science Center at Houston\/McGovern Medical School, Houston, TX AND Destiny F. Chau, MD -Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 5-year-old boy presents for urgent needle pericardiocentesis under ultrasound guidance. He has a pericardial effusion with signs of tamponade physiology, including pulsus paradoxus of -20 mmHg. In addition to cardiac tamponade, which of the following diseases is MOST likely to demonstrate abnormal pulsus paradoxus?\r\n”,”desc”:”EXPLANATION \r\nCardiac tamponade is characterized by compression of the cardiac chambers leading to hemodynamic compromise due to excessive pressure from the accumulation of fluid in the pericardial space. As the intrapericardial volume is relatively fixed, the rate of fluid accumulation and the compliance of the pericardial sac determine the pressure change within this space. When fluid accumulates in a short period of time, even small volumes can result in rapid increases in pressure. The elevated pericardial pressure transmits to the cardiac chambers compromising cardiac filling and ultimately decreasing cardiac output. In contrast, chronic pericardial effusions are defined as those that accumulate over a period of time greater than three months, thereby allowing the pericardial cavity to accommodate fluid without serious hemodynamic compromise up until a critical volume is reached at a later time point. The prolonged time course allows for compensatory mechanisms to develop, such as tachycardia, vasoconstriction, and fluid retention. These mechanisms allow for larger volumes to accumulate before tamponade physiology occurs. Common etiologies of pericardial effusions trauma, autoimmune disease, malignancy, connective tissue disorders, and post-pericardiotomy syndrome. \r\n\r\nPatients present with dyspnea, orthopnea, and chest discomfort. Signs include jugular venous distension, systemic hypotension, tachycardia and pulsus paradoxus. Pulsus paradoxus is an exaggeration of the normal decrease in systolic blood pressure of greater than 10 mmHg during normal spontaneous inspiration and is a key diagnostic feature of cardiac tamponade. It results from the effect of ventricular interdependence during the respiratory cycle being exaggerated by tamponade physiology. During inspiration, venous return is augmented which increases right ventricular volume. The increased right ventricular volume causes a shift of the ventricular septum to the left, thereby reducing left ventricular preload leading to a decrease in cardiac output and systemic blood pressure. In patients with large effusions, an electrocardiogram may demonstrate lower voltages and \u201celectrical alternans\u201d, which is characterized by beat-to-beat variation in QRS amplitude and axis due to excessive movement of the heart within the pericardial fluid. Echocardiographic findings include diastolic collapse of the right atrium and right ventricle, and dilation of the inferior vena cava. Pulsus paradoxus is not unique to cardiac tamponade. It is also associated with several other clinical conditions, which include acute asthma, chronic obstructive pulmonary disease exacerbation, and severe hypovolemia. Acute asthma leads to pulsus paradoxus by several mechanisms, including the following: (1) Highly negative intrathoracic pressures during inspiration further augments systemic venous return and decreases left ventricular preload via septal shift; (2) excessively negative intrathoracic pressure during inspiration increases left ventricular afterload; and, (3) lung hyperinflation increases right ventricular afterload by compressing the pulmonary arteries, which further reduces left ventricular preload.\r\n\r\nCardiac tamponade requires treatment with prompt decompression of the pericardial sac to prevent further hemodynamic compromise and cardiovascular collapse. Sedation and anesthesia can lead to cardiovascular collapse by myocardial depression, vasodilation, and blunting of the compensatory sympathetic mechanisms. In addition, positive pressure ventilation can further compromise venous return and exacerbate cardiac chamber compression, increasing the risk of circulatory collapse. Maintenance of compensatory mechanisms such as relative tachycardia, adequate preload, preservation of contractility and spontaneous ventilation are important to maintain cardiac output. Excessive tachycardia and hypotension in the presence of high ventricular end diastolic pressures can also compromise coronary artery perfusion.\r\n\r\nThe key goals of anesthetic management for subxiphoid percardiocentesis are to allow drainage of pericardial fluid while minimizing the risk of cardiovascular collapse. The safest option is usually local infiltration combined with small doses of sedative medications titrated slowly while maintaining spontaneous ventilation. Medications, fluids, and blood products must be immediately available to treat cardiovascular collapse. Depending on the clinical status of the patient, presence of a surgical team with the patient prepped and draped, before induction of anesthesia, may be required in case a subxiphoid incision is necessary emergently. If surgical drainage under general anesthesia is planned, partial drainage of the pericardial fluid under minimal sedation and local anesthesia may improve cardiovascular reserve and improve hemodynamic stability, allowing for safer induction of anesthesia and intubation with positive pressure ventilation.\r\n\r\nA single-center, retrospective study in a tertiary care children\u2019s hospital by Herron et al analyzed their experience with 127 pediatric patients who underwent 153 pericardiocentesis procedures over a 20-year period. The most common etiology of effusion was post-cardiotomy syndrome in 44% of patients. Approximately 60% of the procedures were performed in the cardiac catheterization laboratory. The overall procedural success rate was 92%. Of note, procedures performed at the bedside had a significantly higher failure rate at 17% than those performed in the catheterization laboratory at 1% (p < 0.01). The incidence of adverse events was 4.6%, which included hemopericardium needing emergent surgery, hemopericardium with hypotension, seizure during induction of anesthesia, and needle puncture of the right ventricle.\r\n\r\nThe correct answer is acute asthma, which can result in pulsus paradoxus as explained above. Aortic stenosis characteristically results in a low amplitude and delayed pulse, known as \u201cpulsus parvus et tardus\u201d. This may be better appreciated with an arterial line or spectral Doppler downstream of the aortic valve. Pulsus alternans is an arterial pulse with the pattern of alternating strong and weak beats, which is associated with severe ventricular dysfunction. The most likely mechanism is that the poorly contractile left ventricle has a reduced stroke volume which leads to an increased end-diastolic volume for the subsequent contraction, resulting in alternating weak and strong pulses. Again, this is more easily appreciated if an arterial line is in place.\r\n\r\nREFERENCES \r\nAdler Y, Charron P, Imazio M, et al. 2015 ESC Guidelines for the diagnosis and management of pericardial diseases: The Task Force for the Diagnosis and Management of Pericardial Diseases of the European Society of Cardiology (ESC)Endorsed by: The European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J<\/em>. 2015;36(42):2921-2964. doi:10.1093\/eurheartj\/ehv318\r\n\r\nJohnson J, Horner J, Cetta F. Pericardial Diseases. In: Shaddy RE, Penny DJ, Feltes TF, Cetta, Mital S, eds. Moss and Adams\u2019 Heart Disease in Infants, Children and Adolescents<\/em>. 10th ed. Philadelphia, PA: Wolters Kluwer; 2021:1393-1406.\r\n\r\nMckenzie I, Markakis Zestos M, Stayer S, Andropoulos D. Anesthesia for Miscellaneous Diseases. In: Andropoulos D, Mossad E, Gottlieb, eds. Anesthesia for Congenital Heart Disease<\/em>. 3rd ed. Hoboken, New Jersey: Wiley Blackwell; 2015:615-618.\r\n\r\nSarkar M, Bhardwaj R, Madabhavi I, Gowda S, Dogra K. Pulsus paradoxus. Clin Respir J<\/em>. 2018; 12:2321-2331. \r\n\r\nHerron C, Forbes TJ, Kobayashi D. Pericardiocentesis in children: 20-year experience at a tertiary children\u2019s hospital. Cardiol Young<\/em>. 2022; 32 (4): 606\u2013611. doi: 10.1017\/S104795112100278X”,”hint”:””,”answers”:{“6y5pa”:{“id”:”6y5pa”,”image”:””,”imageId”:””,”title”:”A. Aortic stenosis”},”r44ts”:{“id”:”r44ts”,”image”:””,”imageId”:””,”title”:”B. Acute asthma”,”isCorrect”:”1″},”d9pek”:{“id”:”d9pek”,”image”:””,”imageId”:””,”title”:”C. Severe ventricular dysfunction”}}}}}

{“questions”:{“60trt”:{“id”:”60trt”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Authors: Meera Gangadharan, MBBS, FAAP, FASA – Children\u2019s Memorial Hermann Hospital, McGovern Medical School, Houston, TX AND Destiny F. Chau, MD – Arkansas Children\u2019s Hospital\/University of Arkansas for Medical Sciences, Little Rock, AR \r\n\r\nA 15-year-old boy palliated with the Fontan procedure has a history of plastic bronchitis refractory to maximal medical treatment. A diagnostic cardiac catheterization demonstrates a patent Fontan pathway with an open fenestration, Fontan pressure of 15 mm Hg, a pulmonary vascular resistance of 2.5 Woods units, and a transpulmonary gradient of 5 mm Hg with a baseline SpO2 of 92% in room air. Which of the following interventions is MOST appropriate for the management of the patient\u2019s plastic bronchitis?”,”desc”:”EXPLANATION \r\nThe Fontan physiology has a significant adverse impact on the lymphatic system. Chronic venous hypertension characterizing the Fontan circulation causes a shift in Starling forces, which favors fluid accumulation in the interstitial tissue. Additional demand for lymphatic fluid clearance may be due to the following: 1) hypoalbuminemia; 2) increased lymph production due to elevated inferior vena cava pressure and hepatic congestion; 3) diaphragmatic dysfunction leading to flow reversal in the portal vein; 4) direct capillary leak due to endothelial dysfunction; 5) low cardiac output and, 6) direct injury to lymphatic structures, such as the thoracic duct, during surgical procedures. Lymphatic vessels become tortuous, dilated, and develop collaterals to accommodate the increased volume and abnormal flow of lymphatic fluid. Inadequate lymph drainage leads to the development of pleural effusions, chylothorax, ascites, protein losing enteropathy and plastic bronchitis. These are all components of a \u201cfailed Fontan circulation\u201d and lead to increased morbidity and mortality. \r\n\r\nPlastic bronchitis has a prevalence of approximately 4-5% in Fontan patients and is associated with a 5-year mortality of up to 50%. The exudation of proteinaceous material into the airways can lead to cast formation, potentially resulting in significant respiratory symptoms and total airway obstruction. Medical management includes airway clearance, bronchodilators, aggressive chest physiotherapy, mucolytic therapy with N-acetylcysteine and\/or dornase-alpha, diuretics, pulmonary vasodilators, aerosolized tissue plasminogen activator, aldosterone inhibitors and a low-fat diet to decrease lymphatic fluid production and flow.\r\n\r\nFollowing failure of medical therapy and after fully addressing reversible causes of lymphatic failure, interventions to decompress the lymphatic system or to occlude abnormal lymphatic vessels are the next options. There are several interventions for lymphatic decompression including surgical decompression, percutaneous thoracic duct decompression, thoracic duct stenting, and creation of a lymphovenous anastomosis. Occlusion techniques include lymphatic embolization, thoracic duct embolization, selective lymphatic duct embolization and thoracic duct ligation. Thoracic duct decompression is surgically accomplished with anastomosis of the left innominate vein to the common atrium. The major disadvantages of this procedure include the need for cardiopulmonary bypass, creation of a right-to-left shunting with resultant cyanosis, and the unknown long-term consequences of lymphatic return directly to the systemic circulation that bypasses the pulmonary circulation. Perhaps the most efficacious option is orthotopic heart transplantation, which is typically reserved for end-stage \u201cfailing Fontan\u201d physiology. However, in recent years, the central role of the lymphatic system in the pathophysiology of plastic bronchitis has been recognized, and percutaneous lymphatic intervention has emerged as an additional therapeutic approach for plastic bronchitis prior to heart transplantation. \r\n\r\nDori et al reported the results of selective lymphatic embolization using Dynamic Contrast-enhanced Magnetic Resonance Lymphangiography (DCMRL) and T2-weighted MRI in 17 of 18 total patients with plastic bronchitis. They were followed for a median of 315 days, with 88% experiencing significant symptomatic improvement, including temporary resolution of cast formation. The procedure involved identifying a target lymphatic vessel by injecting contrast into the inguinal lymph nodes followed by MR imaging to illustrate the passage of contrast through the lymphatic system in real time, allowing for identification of lymphatic leakage and flow disturbances. MRI or lymphangiogram or both illustrated retrograde lymphatic flow toward the lung parenchyma in 16 patients. Of the 18 patients, 17 underwent either embolization or thoracic duct stenting, thereby rerouting lymphatic flow to provide a measure of symptomatic relief and improvement in quality of life. Clearly however, these procedures do not address the root cause of elevated central venous pressures and continued attention to optimization of the Fontan physiology\/pathway is imperative. \r\n\r\nThe patient in the stem has an open fenestration and Fontan hemodynamics that are within the expected range. There is also normal pulmonary vascular resistance, and the transpulmonary gradient is not elevated. Thus, balloon dilation of the fenestration and treatment with bosentan will be of minimal benefit. Given the failure of maximal medical therapy, selective lymphatic embolization should be considered as the next treatment modality and prior to orthotopic heart transplantation, though often a curative treatment for plastic bronchitis. Unfortunately, selective lymphatic embolization is performed at very few centers currently, which may necessitate the use of other treatment modalities mentioned earlier in the explanation (i.e. thoracic duct ligation).\r\n\r\n \r\nREFERENCES \r\nRychik J, Atz AM, Celermajer DS, et al. Evaluation and management of the child and adult with Fontan circulation: A scientific statement from the American Heart Association. Circulation<\/em>. 2019;140(6):e234-e284. \r\n\r\nRoch\u00e9Rodr\u00edguez M, DiNardo JA. The lymphatic system in the Fontan patient-pathophysiology, imaging, and interventions: what the anesthesiologist should know. J Cardiothorac Vasc Anesth<\/em>. 2022;36(8 Pt A):2669-2678. \r\n\r\nDori Y, Keller M, Rome J, et al. Percutaneous lymphatic embolization of abnormal pulmonary lymphatic flow as treatment of plastic bronchitis in patients with congenital heart disease. Circulation<\/em>. 2016;133:1160-1170.”,”hint”:””,”answers”:{“b3yf2”:{“id”:”b3yf2″,”image”:””,”imageId”:””,”title”:”A) Selective lymphatic embolization “,”isCorrect”:”1″},”nxgzu”:{“id”:”nxgzu”,”image”:””,”imageId”:””,”title”:”B) Balloon dilation of Fontan fenestration”},”brlfw”:{“id”:”brlfw”,”image”:””,”imageId”:””,”title”:”C) Initiation of Bosentan\r\n\r\n”}}}}}

{“questions”:{“ibb1f”:{“id”:”ibb1f”,”mediaType”:”image”,”answerType”:”text”,”imageCredit”:””,”image”:””,”imageId”:””,”video”:””,”imagePlaceholder”:””,”imagePlaceholderId”:””,”title”:”Author: Sana Ullah, MB, ChB, FRCA – Children\u2019s Medical Center, Dallas, TX \r\n\r\nA previously healthy 14-year-old girl is undergoing evaluation for pulmonary hypertension due to a strong family history. Which of the following gene mutations is MOST likely to be present in this patient?”,”desc”:””,”hint”:””,”answers”:{“mdeo1”:{“id”:”mdeo1″,”image”:””,”imageId”:””,”title”:”A. JAG1″},”43x7a”:{“id”:”43x7a”,”image”:””,”imageId”:””,”title”:”B. BMPR2″,”isCorrect”:”1″},”si9w3″:{“id”:”si9w3″,”image”:””,”imageId”:””,”title”:”C. PTPN11″}}}},”results”:{“m9iyu”:{“id”:”m9iyu”,”title”:””,”image”:””,”imageId”:””,”min”:”0″,”max”:”1″,”desc”:””,”redirect_url”:”https:\/\/ccasociety.org\/wp-content\/uploads\/2024\/05\/CCAS-QOW-Posted-5-9-2024.pdf”}}}