Vasodilator Agents in Pediatric Cardiac Surgery with Cardiopulmonary Bypass

Surgical management of congenital heart disease has become regularly performed in tertiary hospitals worldwide. Although routinely needed, cardiopulmonary bypass (CPB) deleteriously affects physiological processes being among the main causes of increased morbidity in cardiac surgery, especially in neonates and children.Recent studies have shown that vasodilator agents’ use during CPB improved peripheral tissue perfusion while maintaining high flow during bypass. Hence, an improvement in perfusion and oxygenation of the skin, musculature and intestinal mucosa has been demonstrated, with favorable result throughout the postoperative period.These agents, by reducing systemic vascular resistance (SVR), lead to greater peripheral blood flow, improvement in peripheral perfusion, decreased base deficit and lactic acidosis and therefore improved respiratory and circulatory status.The present article reviews the main aspects of vasodilator agents most commonly used in pediatric cardiac surgery with CPB, including: chlorpromazine, phentolamine, phenoxybenzamine, sodium nitroprusside, volatile anesthetic agents, calcium channel blockers, angiotensin blockers and inodilators.

Papel diagnóstico de la ecocardiografía. Metástasis cardíacas / Role diagnostic of echocardiography. Cardiac metastases

Hasta hace unas décadas el diagnóstico premortem de un tumor cardíaco era muy difícil, la gran mayoría de observaciones eran autópsicas y el interés que esta patología tenía para el médico era puramente académico. A partir de los años setenta, con la introducción de la ecocardiografía y el desarrollo de la cirugía cardíaca, son posibles el diagnóstico y el tratamiento quirúrgico efectivo de los mismos

Until a few decades ago the premortal diagnosis of a cardiac tumor was very difficult, the majority of observations were autopsic and the interest was purely academic. From the 1970s, with the introduction of echocardiography and the development of cardiac surgery, diagnosis and effective surgical treatment of the same are possible

Comparison of cardiac allograft vasculopathy in heart and heart-lung transplantations: a 15-year retrospective study.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is a major factor limiting long-term survival after heart transplantation (HTx). Specific determinants of CAV and long-term outcome after CAV occurrence have been poorly investigated after heart-lung transplantation (HLTx). METHODS: Between January 1996 and December 2006, 79 patients underwent HLTx (36.3 ± 12.2 years old; 47% men) and 141 patients underwent HTx (49.2 ± 12.3 years old; 77% men) at two different institutions. CAV grading was reviewed in both groups according to the 2010 standardized nomenclature of the International Society for Heart and Lung Transplantation. The mean post-transplant follow-up was 94 (1 to 181) months. RESULTS: Overall 10-year survival rate was 58% after HTx and 43% after HLTx (p = 0.11). The Grade 1 (or higher) CAV-free survival rate was 95% at 4 years and 69% at 10 years after HLTx, and 77% and 39%, respectively, after HTx (p < 0.01). Mean cyclosporine blood levels were similar between the groups at 3, 6, 12, 24 and 36 months. The main causes of mortality beyond 5 years after HTx and HLTx were malignancies and bronchiolitis obliterans, respectively. By multivariate analysis, recipients who developed >3 acute myocardial rejections during the first year post-transplant were exposed to a higher risk of CAV (95% CI 1.065 to 2.33, p = 0.02). Episodes of acute pulmonary rejection and bronchiolitis obliterans were not associated with an increased risk of CAV (p = 0.52 and p = 0.30). CONCLUSION: HLTx recipients appeared protected from CAV compared with HTx patients in this retrospective study. Repeated acute cardiac rejections were independent predictors of CAV. Unlike bronchiolitis obliterans, CAV had a very low impact on long-term survival after HLTx.

Preserving mitochondrial function prevents the proteasomal degradation of GTP cyclohydrolase I.

The development of pulmonary hypertension is a common accompaniment of congenital heart disease (CHD) with increased pulmonary blood flow. Our recent evidence suggests that asymmetric dimethylarginine (ADMA)-induced mitochondrial dysfunction causes endothelial nitric oxide synthase (eNOS) uncoupling secondary to a proteasome-dependent degradation of GTP cyclohydrolase I (GCH1) that results in a decrease in the NOS cofactor tetrahydrobiopterin (BH(4)). Decreases in NO signaling are thought to be an early hallmark of endothelial dysfunction. As l-carnitine plays an important role in maintaining mitochondrial function, in this study we examined the protective mechanisms and the therapeutic potential of l-carnitine on NO signaling in pulmonary arterial endothelial cells and in a lamb model of CHD and increased pulmonary blood flow (Shunt). Acetyl-l-carnitine attenuated the ADMA-mediated proteasomal degradation of GCH1. This preservation was associated with a decrease in the association of GCH1 with Hsp70 and the C-terminus of Hsp70-interacting protein (CHIP) and a decrease in its ubiquitination. This in turn prevented the decrease in BH(4) levels induced by ADMA and preserved NO signaling. Treatment of Shunt lambs with l-carnitine also reduced GCH1/CHIP interactions, attenuated the ubiquitination and degradation of GCH1, and increased BH(4) levels compared to vehicle-treated Shunt lambs. The increases in BH(4) were associated with decreased NOS uncoupling and enhanced NO generation. Thus, we conclude that L-carnitine may have a therapeutic potential in the treatment of pulmonary hypertension in children with CHD with increased pulmonary blood flow.

Fast track surgery: realidades y dificultades / Fast-track surgery: the facts and the challenges

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Reconstruction of bilateral branch pulmonary artery stenosis caused by Takayasu's aortitis.

A 63 year-old female presented with dyspnea on exertion. Her chest X-ray showed cardiomegaly, and right ventricular overload and tricuspid regurgitation were detected. Her pulmonary ventilation and blood flow scintigraphy findings were suspicious of pulmonary vascular disease; the diagnosis was pulmonary hypertension and bilateral branch pulmonary artery stenosis. After the inflammation settled, the stenotic bilateral branch pulmonary artery was reconstructed with a prosthetic vessel and the pulmonary pressure normalized immediately. A resected specimen revealed that the stenotic changes were from Takayasu's disease. The patient's postoperative course was uneventful, and pulmonary ventilation and blood scintigraphy returned to an almost normal range. At follow-up 5 years and 6 months after the operation, there was no evidence of pulmonary artery disease (eg, stenosis and/or ischemia) or of any change in the central vessels of the retina, the so-called Takayasu's retinopathy.

Cirugía de Glenn en el departamento de cardiopediatría INCOR-EsSalud / Glenn's surgery in the department of cardiopediatric incor-EsSalud

Objetivo: En el presente estudio retrospectivo realizado en el INCOR tiene como objetivo principal analizar los factores determinantes en el resultado quirúrgico de la cirugía de Glenn. Material y Métodos: Entre enero de 1999 y diciembre de 2002 se intervinieron 37 niños con esta técnica quirúrgica en el INCOR-EsSalud, cuyas edades oscilaron entre 5 meses y catorce años, los pesos fueron desde 4.5 hasta 41 kilos, hubieron 25 hombres y 11 mujeres, procedentes 5 ciudades de altura, 23 de la región costa y tres de la selva. Resultados: La mortalidad fue 8.1 por ciento y se asoció un valor de la presión de la arteria pulmonar igual o superior a 30 mmHg a mayor morbimortalidad. De igual manera un peso menor de 7 kilos, edad menor de un año, anormalidades anatómicas cardiacas complejas y pacientes con antecedente de enfermedades respiratorias frecuentes tuvieron una mayor estancia en la UCI post quirúrgica, los pacientes con fisiopatología de bajo flujo pulmonar no condicionaron una variable clínica de importancia en la morbimortalidad. La tasa de supervivencia a tres años fue del 92 por ciento. Conclusiones: Este tipo de cirugía es una buena alternativa terapéutica para las cardiopatías congénitas de corazón univentricular. La presión de la arteria pulmonar, el peso, la edad, así como los antecedentes pre-quirúrgicos, son variables importantes relacionadas con la evolución de estos pacientes.

[Pulmonary thromboendarterectomy: an effective surgical treatment for cor pulmonale due to chronic pulmonary emboli]. / Pulmonalistrombo-endarteriëctomie: een effectieve chirurgische behandeling voor patiënten met cor pulmonale door chronische longembolie.

OBJECTIVE: To evaluate the initial experience with pulmonary thromboendarterectomy for cor pulmonale due to chronic pulmonary embolism. METHOD: In the period 1 April 1996 to 31 October 2001, 18 patients with right ventricular failure due to chronic thromboembolic pulmonary hypertension were operated on. Their mean age was 54 (SD: 14) years. Preoperatively, all of the patients were in functional New York Heart Association (NYHA) class III or IV. Pulmonary angiography revealed pulmonary hypertension with an increased pulmonary vascular resistance, as well as typical angiographic signs of unresolved chronic emboli. Pulmonary thromboendarterectomy was performed via median sternotomy, using extracorporeal circulation and intermittent deep hypothermic circulatory arrest. The patients were monitored via the outpatients' department. RESULTS: From a technical viewpoint, the procedure was performed successfully in all of the patients. Initially the pulmonary thromboendarterectomy was performed unilaterally (n = 7), which did not decrease pulmonary artery pressure significantly. The following 11 patients were treated bilaterally; in them thromboendarterectomy required an average of circulatory arrest totalling 64 (SD: 30) min with 161 (SD: 35) min of myocardial ischemia. After bilateral pulmonary thromboendarterectomy, the pulmonary artery pressure decreased from 45 (SD: 13) to 28 (SD: 9) mmHg (p = 0.001). Reperfusion pulmonary oedema, requiring prolonged ventilation, occurred in 3 patients. There was no operative or later mortality. At a mean follow-up of 28 (SD: 19) months, all but one of the patients were in functional NYHA class I or II. Echocardiography revealed reduced right ventricular dimensions and pulmonary artery pressures. One patient, with mainly distally located obstructions, exhibited no substantial improvement. CONCLUSION: The initial experience with pulmonary thromboendarterectomy for patients with cor pulmonale due to chronic pulmonary emboli demonstrated satisfactory mid-term follow-up data.

Paradoxical embolism. An old but, paradoxically, under-estimated problem.

The theoretical model of paradoxical embolism requires the presence of four parameters, namely, arterial embolism, venous thrombus, abnormal intracardiac communication and right-to-left shunt. Many aspects, however, of this well known entity are under consideration; diagnosis is often difficult to be established and the long term efficacy of preventive measures is undefined. We comment on a case report of recurrent paradoxical embolism with popliteal vein thrombosis and patent foramen ovale, and we briefly review the literature.

[Chronic cor pulmonale and refractory hypoxemia following pulmonary embolism in a six-month-old infant: surgical management by thromboendarterectomy]. / Coeur pulmonaire chronique postembolique et hypoxémie réfractaire chez un nourrisson de six mois: prise en charge chirurgicale par thromboendartériectomie.

UNLABELLED: A diagnosis of pulmonary embolism is uncommon in the infant and the child, and chronic cor pulmonale secondary to pulmonary embolism is an even rarer occurrence. CASE REPORT: In this study, a case of pulmonary embolism in a 6-month-old male infant has been reported. His past history included preterm birth, and severe bronchopulmonary dysplasia, with prolonged oxygen dependency. The positive diagnosis was based on cardiac ultrasound examination, with the direct imaging of a right pulmonary arterial thrombus. Surgical thromboendarterectomy was performed, with a long-term favorable outcome. CONCLUSION: After excluding from the diagnosis those hemostatic disorders known to be thrombogenic, the most likely hypothesis was retained, i.e., that it was catheter-related. A central venous catheter had been inserted during the neonatal period, and was probably responsible for the embolism. The clinical characteristics and the diagnostic and therapeutic aspects of chronic postembolic cor pulmonale have been discussed in the light of the present findings.

[Post-embolic chronic pulmonary heart disease: a case report]. / Coeur pulmonaire chronique post-embolique: à propos d'une observation.

Echocardiography and pulmonary scintigraphy demonstrated post-embolic chronic cor pulmonale in a six-year-old woman presenting with dyspnoea. The patient's symptoms deteriorated during subsequent thromboembolic episodes, despite treatment consisting of oral anticoagulants and diuretics. After discussing the pathophysiology and diagnostic methods, the authors emphasize the limits of medical treatment of post-embolic chronic cor pulmonale and the value of two surgical treatments: thromboendarterectomy and lung transplantation. They also recall the precise selection criteria for lung transplantation.

Technical aspects of adult lung transplantation.

This article describes the authors' current technical preferences for the performance of isolated single lung transplantation and bilateral sequential single lung transplantation. The current techniques are the result of lessons learned in the performance of over 400 lung transplant operations at Washington University School of Medicine since 1987.

Coronary to bronchial artery anastomosis in patients with noncyanotic cardiopulmonary disease: report of seven cases.

An angiographically visible coronary to bronchial artery anastomosis was found in seven (0.12%) of 6045 patients with noncyanotic cardiopulmonary disease who underwent coronary angiography between 1989 and 1995. Aortitis syndrome was associated with four patients, whereas pulmonary embolism, aortic regurgitation and vasospastic angina were the diagnoses in the others. Coronary stenotic lesions were not observed in any patients. In five of six patients who underwent pulmonary perfusion scintigraphy, perfusion defect was observed in the area supplied by the bronchial artery, which had the anastomosis to the coronary artery. In each patient this anastomosis seemed to function as collateral circulation, compensating for decreased perfusion in either the lung or the heart. When coronary to bronchial artery anastomosis is found, ischemic conditions in either the lung or the heart are likely.

Bilateral sequential lung transplantation for pulmonary alveolar microlithiasis.

Pulmonary alveolar microlithiasis (PAM) is characterized by deposition of calcium phosphate within the alveolar airspaces. There is currently no effective medical therapy and affected individuals may progress to end-stage lung disease requiring transplantation. Two patients with PAM underwent bilateral sequential lung transplantation. This study reviews the clinical manifestations of PAM and discusses the particular difficulties that may be encountered in the use of lung transplantation as treatment for this uncommon disease. Also addressed is the question of recurrence in the allograft.

Acute right heart failure due to adenotonsillar hypertrophy.

A case is presented in which a child with underlying chronic lung disease, developed cor pulmonale and severe pulmonary hypertension as a result of adenotonsillar hypertrophy. His cardiac function acutely decompensated with an upper respiratory infection which exacerbated his obstructive sleep symptoms. Pre and postoperative documentation of cardiopulmonary function was critical in the peri-operative management of this patient. His severe pulmonary hypertension was stabilized using a nasopharyngeal airway and medications pre-operatively, in order to minimize his risk of anesthesia. He continued to require careful monitoring and manipulation of his medications after adenotonsillectomy and bronchoscopy. Serial echocardiograms documented the effects of the various interventions implemented in this patient. Severe acute right heart failure is an unusual complication of obstructive sleep apnea. However, this may become more common as more children survive prematurity and its associated chronic lung disease. These children may have subclinical lung disease and/or chronic pulmonary hypertension even after they no longer require supplemental oxygen and bronchodilators. Because these children are often tenuous, with regard to their cardiopulmonary function, they may be at increased risk to develop significant complications related to obstructive sleep apnea. It is important that a physician familiar with the management of pulmonary hypertension be involved in the care of these patients.

Informe del primer trasplante de bloque cardiopulmonar realizado en México / Report of the first cardiopulmonar block transplantation performed in Mexico

Objetivo: Informar sobre el primer trasplante cardiopulmonar que se realiza en México. Diseño: Informe de caso clínico. Se trató de paciente femenino de 47 años de edad, con hipertensión pulmonar severa y defecto septal auricular en clase funcional III. El día 4 de junio de 1995, en el Hospital de Cardiología del Centro Médico Nacional Siglo XXI se obtuvo bloque cardiopulmonar a partir de donación múltiple y se traspantó a la paciente. Resultados: El tiempo de hipotermia isquémica fue de 3 horas. La actividad cardíaca reinició a los 14 segundos de reperfusión. El destete de la derivación cardiopulmonar se efectuó sin problemas. A las 36 horas presentó abdomen agudo por hemoperitoneo, se requirió laparotomía por hemostasia, además de detectarse pancreatitis. El bloque cardiopulmonar funcionó adecuadamente por 5 días al cabo de los cuales presentó aumento de cortocorcuitos, hipoxemia, bajo gasto cardíaco y falleció al sexto día. El informe de la autopsia fue: pancreatitis edematosa, rechazo de corazón y pulmón, cambios isquémicos del miocardio y edema pulmonar. Conclusión: Es factible realizar trasplante cardiopulmonar en nuestro país. Las complicaciones coinciden con las descritas en la literatura mundial

[Lung transplantation]. / Lungentransplantation.

Human lung transplantation was successfully performed in the early eighties and is now an option for patients with endstage lung disease, which is associated with poor survival. Most frequent indications for lung transplantation are emphysema, cystic fibrosis, fibrosing alveolitis, primary pulmonary hypertension and Eisenmenger's syndrome. Single lung transplantation (SLT) is most often performed in emphysema, fibrosing alveolitis and other diseases which are not associated with chronic infection of the lung. Double lung transplantation was recently replaced by the technique of sequential single lung or bilateral lung transplantation (BLT). Cardiopulmonary bypass can often be avoided and problems of the airway anastomosis are less frequent using BLT. Main indications for this procedure are cystic fibrosis, bronchiectasis and primary pulmonary hypertension (PPH). In PPH often only SLT is performed. Cor pulmonale is reversible following SLT or BLT even if the heart is not replaced. Combined heart-lung transplantation (HLT) is reserved for some cases of Eisenmenger's syndrome and few centers still prefer HLT in patients with cystic fibrosis. Patients are usually accepted for transplantation when they are considered to have life expectancy of 12 to 24 months. Quality of life and physical working capacity are severely decreased and patients suffer dyspnea NYHA grade III or IV. Most of the patients are hypoxic and need continuous oxygen therapy. Hypercapnia is also a negative predictive factor for survival without transplantation. In PPH cardiac index of less than 2 litres/m2 is associated with poor outcome. Not only absolute values for FEV1 and pO2 have to be considered in finding the best moment for assessment for transplantation but the clinical course of the disease during previous months and years also has to be taken into account. Contraindications to transplantation include acute infection, concomitant diseases of other organs, bronchial carcinoma and psychiatric disorders if noncompliance is likely. To achieve good results after lung transplantation, proper donor and recipient selection, experienced surgery and careful postoperative management are essential. Complications must be diagnosed early to provide effective treatment. Most complications occur within the first months after surgery. Early complications include primary organ failure, pleural bleeding, problems at the site of the airway anastomosis, infection and acute rejection. Acute rejection is common but can be treated successfully if diagnosed early.(ABSTRACT TRUNCATED AT 400 WORDS)

Thromboxane A2 and prostacyclin biosynthesis in children and adolescents with pulmonary vascular disease.

BACKGROUND: The pathogenesis of pulmonary vascular disease in children with congenital heart disease is incompletely understood. Thromboxane (TX) A2 and prostacyclin (PGI2) have opposing effects on platelet aggregation and pulmonary vascular smooth muscle. An imbalance in their biosynthesis could contribute to the progressive increase in pulmonary vascular resistance seen in older untreated patients with pulmonary hypertensive congenital heart disease and the thrombotic complications they may develop. METHODS AND RESULTS: We investigated TXA2 and PGI2 biosynthesis in 15 young children (0.2 to 2.25 years old) with congenital heart disease with increased pulmonary blood flow and potentially reversible pulmonary vascular disease by measuring urinary excretion of 2,3-dinor-TXB2 and 2,3-dinor-6-oxoprostaglandin (PG) F1 alpha and compared the findings with those in 16 healthy children (0.5 to 2.8 years old). 2,3-Dinor-TXB2 excretion was greater in the patients than in control subjects (1253 +/- 161 versus 592 +/- 122 ng/g creatinine; P < .001). Excretion of 2,3-dinor-6-oxo-PGF1 alpha was 452 +/- 54 compared with 589 +/- 95 ng/g creatinine in control subjects. In 5 patients who underwent successful cardiac surgery > or = 1 year later excretion of 2,3-dinor-TXB2 decreased from 1100 +/- 298 to 609 +/- 131 ng/g creatinine (P < .05), a value comparable to those in 5 healthy children of similar age (749 +/- 226 ng/g creatinine). We also compared 15 patients (11 to 23 years old) with advanced irreversible pulmonary vascular disease with 19 healthy control subjects (10 to 23 years old). The ratio of TX to PGI2 metabolite excretion was greater in the patients than in control subjects (3.5 +/- 0.6 versus 2.0 +/- 0.3; P < .05). CONCLUSIONS: There is increased 2,3-dinor-TXB2 excretion in children with congenital heart disease and a high pulmonary blood flow that may reflect an imbalance in biosynthesis of TXA2 and PGI2 in the pulmonary vascular bed. The imbalance may contribute to the progressive development of increased pulmonary vascular resistance and persists in older patients whose heart defects are uncorrected.