Stent Implantation for Effective Treatment of Refractory Chylothorax due to Superior Vena Cava Obstruction as a Complication of Congenital Cardiac Surgery

Chylothorax is a serious complication of congenital cardiac surgery and is significantly associated with increased morbidity and mortality. Central venous obstruction, which is often related to the insertion of central venous catheters for postoperative management, is known to be an important risk factor for treatment failure and mortality associated with this condition. We present the case of a 6-month-old girl with refractory chylothorax after surgical repair of tetralogy of Fallot. The chylous drainage continued for more than 2 months despite maximal conservative therapy (water restriction, total parenteral nutrition, and infusion of somatostatin and steroid) and surgical ligation of the thoracic duct. Subsequently, we observed stenosis of the superior vena cava (SVC) caused by large thrombi possibly associated with the prolonged use of central venous catheter placed in the internal jugular vein. Because transcatheter balloon dilation failed to relieve the stenosis, we performed stent implantation for the SVC and innominate vein. After the procedure, chylous drainage dramatically reduced, and the patient was discharged from the hospital. In conclusion, central venous obstruction due to thrombosis should be routinely examined when chylothorax is diagnosed and is resistant to conservative therapy after congenital heart surgery. Stent implantation can effectively relieve the venous obstruction and thus be a life-saving treatment option for this difficult condition

High Serum Levels of Procollagen Type III-N-terminal Amino Peptide in Patients with Congenital Heart Disease

Abstract Objective: The serum concentration of amino-terminal procollagen type III (PIIIP) is considered a useful marker of tissue fibrogenesis. The present study tested the hypothesis that: 1) serum PIIIP levels are elevated in patients with congenital heart disease (CHD) and abnormal hemodynamic loading and/or hypoxemia, 2) PIIIP levels are associated with severity of hemodynamic load or hypoxemia, both of which enhance myocardial fibrosis. Methods and Results: Serum PIIIP levels were measured in 5 groups of CHD patients [42 patients with ventricular septal defect (VSD), 26 with coarctation of the aorta (COA, n=19) or aortic stenosis (AS, n=7), 36 with atrial septal defect (ASD), 39 with pulmonary stenosis (PS) and 20 with tetralogy of Fallot (TOF)]. PIIIP levels of CHD patients were significantly higher than those of 42 control subjects (p<0.05, each). Serum PIIIP levels increased in parallel with increased ventricular volume load in VSD and ASD, and with severity of PS. In TOF patients, PIIIP levels correlated negatively with arterial oxygen saturation. Treatment with angiotensin converting enzyme inhibitor (ACEI) was associated with low levels of PIIIP in COA/AS patients despite existing hemodynamic load. Conclusion: The increased serum PIIIP levels in proportion with the severity of ventricular load or cyanosis suggest enhanced myocardial synthesis of collagen type III in patients with CHD. Suppression of PIIIP level by ACEI suggests the involvement of the renin-angiotensin-aldosterone system in myocardial fibrosis. These data provide the basis for the development of new diagnostic and therapeutic strategies in patients with CHD

Transient Hemodynamic Changes upon Changing a BCPA into a TCPC in Staged Fontan Operation: A Computational Model Study

The clinical benefits of the Fontan operation in treating single-ventricle defects have been well documented. However, perioperative mortality or morbidity remains a critical problem. The purpose of the present study was to identify the cardiovascular factors that dominate the transient hemodynamic changes upon the change of a bidirectional cavopulmonary (Glenn) anastomosis (BCPA) into a total cavopulmonary connection (TCPC). For this purpose, two computational models were constructed to represent, respectively, a single-ventricle circulation with a BCPA and that with a TCPC. A series of model-based simulations were carried out to quantify the perioperative hemodynamic changes under various cardiovascular conditions. Obtained results indicated that the presence of a low pulmonary vascular resistance and/or a low lower-body vascular resistance is beneficial to the increase in transpulmonary flow upon the BCPA to TCPC change. Moreover, it was found that ventricular diastolic dysfunction and mitral valve regurgitation, despite being well-known risk factors for poor postoperative outcomes, do not cause a considerable perioperative reduction in transpulmonary flow. The findings may help physicians to assess the perioperative risk of the TCPC surgery based on preoperative measurement of cardiovascular function