PULMONARY BLOOD DISTRIBUTION AFTER TOTAL CAVOPULMONARY CONNECTION OF DIFFERENT TYPES

Objective.To assess the feature of pulmonary blood flow distribution after total cavopulmonary connection(TCPC)of different types,and to provide the selection of the best type.Methods. Thirty-two consecutive survival patients after TCPC underwent radionuclide lung perfusion imaging. According to the radionuclide counts in the left and right lungs,analyses of the distribution of blood flow from superior venous cava(SVC) and inferior venous cava(IVC)and the whole pulmonary blood flow in both lungs were made. All patients were divided into 4 groups by the the anastomosis between IVC and pulmonary artery.Results. GroupⅠ:The flow ratio of the IVC to left lung was greater than that to the right lung,P≤0.01;the flow ratio of the SVC to right lung was greater than that to the left lung,P≤0.01;and the whole pulmonary blood flow went dominantly to the left lung,P≤0.05,which is not in line with physiological distribution. GroupⅡ:the flows from the SVC and IVC were mixed in the middle of the junction and ran evenly into the right and left lungs,the whole pulmonary blood flow went to both lungs,P≥0.05. Group Ⅲ:the flow ratio of the SVC to both lungs were the same,P≥0.05,and major part from IVC went to the right lung,P≤0.01;the pulmonary blood flow go dominantly to the right lung,P≤0.05,which is in accord with physiological distribution. Group Ⅳ:the flows from the right SVC went to right lung by 100%,P≤0.01,and that from the left SVC went to left lung by 100% too,P≤0.01;the flows from IVC went dominantly to the left lung,with little part to the right lung ,P≤0.05.Conclusions. Different types of TCPC can result in different pulmonary blood distributions. The best flow distribution between the left and right lungs can be obtained by an offset of the IVC anastomosis toward the RPA with widening anastomosis for the patients without persist left superior venous cava(PLSVC).

Total Cavopulmonary Connection:Lateral Tunnel Anastomosis or Extracardiac Conduit?——an Analysis of 114 Consecutive Patients

Objective To compare the postoperative outcomes of patients with the diagnostic univentricular heart undergoing lateral tunnel （LT） operation with extracardiac conduit （EC） operation. Methods- From June 1996 to July 2007, 114 consecutive patients with a single ventricle underwent total cavopulmonary connection （TCPC） in Children＇s Heart Center, lAniversity Hospital Giessen and Marburg GmbH, Germany. A LT was performed in 19 （16.7%） patients, and an EC in 95 （83.3%） patients. The mean age of EC group was 50.8±31.6 （ranging from 22 to 212） months, and that of LT group was 61.5±41.2 （ranging from 30 to 168） months. Early and midterm outcomes of two groups were analyzed.Results One died in LT group （5.3%） and three in EC group （3.2%）. The overall mortality was 3.5%. There was no significant difference in mortality between EC-and-LT groups （P〉0.05）. The postoperative pulmonary arterial pressure, oxygen saturation, and effusion time of two groups had no significant difference （all P〉0.05）. No significant difference in the occurrences of complications （arrhythmias, enteropathy, and thrombosis） was found between two groups after operation （P〉0.05）. Conclusions There seems no difference between LT and EC in the clinical results in the early and middle postoperative stage. Glenn anastomosis followed by an EC seems to have some advantages.

Numerical Investigation of an Idealized Total Cavopulmonary Connection Physiology Assisted by the Axial Blood Pump With and Without Diffuser

In order to improve the surgical treatment of the congenital heart disease patient with single ventricle defect,two axial flow blood pumps,one with diffuser and the other without diffuser,were designed and virtually implanted into an idealized total cavopulmonary connection(TCPC)model to form two types of Pump-TCPC physiological structure.Computational fluid dynamics(CFD)simulationswere performed to analyze the variations of the hemodynamic characteristics,such as flow field,wall shear stress(WSS),oscillatory shear index(OSI),relative residence time(RRT),between the two Pump-TCPC models.Numerical results indicate that the Pump-TCPC with diffuser has better flow field stability,less damage on endothelial cell of vessel wall,and lower risk of vascular injury and thrombosis formation than that without diffuser.

Total Cavopulmonary Connection for Complex Cardiac Anomalies with the Functional Single Ventricle

From Aug. 1999 to Feb. 2001, 8 patients with complex congenital heart diseases, including 5 cases accompanied by hypoplastic left ventricle and 3 by hypoplastic right ventricle, were subjected to total cavopulmonary connection . Eight cases underwent the operation under cardiopulmonary bypass and 7 of whom under no cardiac clamp. Seven cases received cavopulmoanry anastomosis by flaring method and one case by end side anastomosis. All the patients underwent the intracardiac tunnels to drain inferior vena cava and plus 4 mm fenestration except one. The results showed that 6 patients had postoperative oxygen saturation more than 90 %, sinus rhythm, no anastomostic stoma obstruction, no flow reguigitation and CVP<16 cmH 2O. Two patients died postoperatively from high venous pressure of 18—20 cmH 2O, finally from cardiac failure and anoxima. It was concluded that TCPC was an effective treatment for complex congenital cardiac diseases, especially with ventricular maldevelopment. Intracardiac tunnel plus 4 mm fenestration and flaring cavopulmonary anastomosis could prevent the postoperative complications. Larger anastomotic stoma, venous pressure less than 16 cmH 2O and artery saturation more than 90 % might indicate excellent TCPC procedures in our experience.

Pleural drainage following total cavopulmonary connection in the era of central venous catheter

Background Pleural effusion after the Fontan operation contributes significantly to morbidity and prolonged hospitalization. The purpose of the present study was to investigate whether chest tubes placed in different cavities during the surgery would contribute to the drainage and also to evaluate risk factors of thoracic drainage with central venous catheter after total cavopulmonary connection in the era of the central venous catheter. Methods From January 2009 to June 2012, 109 consecutive patients underwent total cavopulmonary connection at Guangdong General Hospital. With 102 patients for investigation, preoperative, intraoperative and postoperative factors were obtained. Thoracic drainage with central venous catheter was whenever necessary. Duration of chest tube drainage and time of thoracic drainage with central venous catheter added up to total duration of pleural drainage. Binary logistic regression using forward LR method was applied for the analysis of the risk factors for thoracic drainage with central venous catheter. Results After total cavopulmonary connection, compared with chest tubes placed in single pleural cavity with or without pericardial or retrosternal cavity, those in both pleural cavities seemed to have the chance of longer hospital stay （P = 0.028）. No other significant differences were obtained in factors of ventilation time, extubated central venous pressure in superior vena cava, ICU stay, total duration of pleural drainage. Sildenafil was the preventive factor for reducing central venous pressure and preventing from postoperative pleural effusion. Conclusions After total cavopulmonary connection, patients with tubes placed in both pleural cavities would not have the chance of shorter total duration of pleural drainage and surprisingly turns out to have longer hospital stay. Sildenafil is a preventive factor for thoracic drainage with central venous catheter.

Cardiac catheterization and comprehensive clinical evaluation after bidirectional Glenn shunt surgery in 60 patients with complex congenital heart disease

Background The bidirectional Glenn shunt surgery is a palliative procedure for patients with complex congenital heart disease（CHD） who are not suitable for biventricular repair in early life. There is limited evidence of successful strategies for long-term hemodynamic stabilization. Furthermore, there have been no data on optimal hemodynamics that could be used as a reference for patients＇ follow-on management. Methods Sixty CHD patients, 44 male and 16 female, with bidirectional Glenn shunt surgery and cardiac catheterization were enrolled at our hospital between January 2014 and December 2016. Pre-and post Glenn shunt percutaneous oxygen saturation（SpO_2）, 6-minute walk test（6 MWT）, superior vena cava pressure（SVCP）, pulmonary arterial pressure（PAP）, pulmonary capillary wedge pressure（PCWP）, pulmonary vascular resistance（PVR）, small pulmonary vascular resistance（s PVR） were measured. Pre-and post-total cavopulmonary connection（TCPC） SpO_2, and in-hospital complications were monitored. The optimal hemodynamic cutoff values for TCPC patient selection were estimated by receive operating characteristic（ROC） curve analysis. Results SpO_2 was significantly increased by bidirectional Glenn shunt surgery（75.42 ± 9.62% to 86.98 ± 7.63%, P 〈 0.001） from 82.70 ± 5.99% to 95.00 ±4.07% in the 47 patients with TCPC. Forty-two patients completed the 6 MWT with a mean distance of 362.7 ±75.0 m and a SpO_2 decrease from 81.80 ± 7.84% to 67.59 ± 1.82%（P 〈 0.001）. The △SpO_2 and 6-minute walk distance（6 MWD） in the 32 who underwent TCPC and ten of them did not reach statistical significance（17.22 ±13.82% vs. 13.87 ± 8.74%, P = 0.08 and 358.88 ± 78.97 m vs. 374.80 ± 62.55 m, P = 0.564]. After cardiac catheterization, 47 patients were selected for TCPC. The right pulmonary artery systolic pressure（s RPAP）, mean right pulmonary artery pressure（m RPAP）, mean left pulmonary artery pressure（m LPAP）, PVR, and s PVR were significantly lower in the TCPC group than in the non-TCPC group. The differences in superior vena cava systolic blood pressure（s SVCP）, mean superior vena cava pressure（m SVCP）, and left pulmonary artery systolic pressure（s LPAP） were not significant. The optimal cutoff values for TCPC were s SVCP ≤ 20 mm Hg（P = 0.025）,s RPAP ≤ 22 mm Hg（P = 0.0001, mRPAP ≤ 13 mm Hg（P =0.003）, s LPAP ≤ 27 mm Hg（P =0.03）, m LPAP ≤ 11 mm Hg（P = 0.01）, PVR ≤ 4.3 Wood U/m^2（P 〈0.0001） and were significantly associated with TCPC selection,except for m SVCP ≤ 19 mm Hg（P = 0.06） and s PVR ≤ 2.0 wood U/m^2（P = 0.0531）. One patient died because of low cardiac output after TCPC. In-hospital mortality was 2.1%. Conclusion The SpO_2 can be significantly improved after bidirectional Glenn shunt and TCPC surgery. The 6 MWT is an index of activity tolerance prior toTCPC. Hemodynamic values of s SVCP ≤ 20 mm Hg, s RPAP ≤ 22 mm Hg, m RPAP ≤ 13 mm Hg, s LPAP ≤ 27 mm Hg, m LPAP ≤ 11 mm Hg, and PVR ≤ 4.3 Wood U/m^2 can help identify post Glenn-shunt patients indicated for TCPC.