Asian Cardiovasc Thorac Ann 2002;10:35-38
© 2002 Asia Publishing EXchange Pte Ltd
Total Cavopulmonary Connection With Extraatrial Tunnel
Zhang Ren Fu, MD,
Gong Han Dong, MD,
Zhu Hong Yu, MD,
Hou Ming Xiao, MD,
Li Xin Min, MD,
Wang Jun, MD,
Song Heng Chang, MD,
Zhang Nan Bin, MD,
Tan Li Li, RN
|
Department of Cardiovascular Surgery Shenyang Northern Hospital Shenyang, Liaoning People's Republic of China
|
|
|
Zhang Ren Fu, MD Tel: 86 24 2390 1822 Fax: 86 24 2390 1822 Department of Cardiovascular Surgery, Shenyang Northern Hospital, 83 Wenhua Road, Shenhe District, Shenyang, Liaoning 110015, People's Republic of China.
|
 |
ABSTRACT
|
|---|
Between April 1997 and February 2000, total cavopulmonary connection with an extraatrial tunnel was used to treat 9 cases of complicated congenital heart disease: single ventricle (4), double-outlet right ventricle (3), mitral atresia (1), and tricuspid atresia (1). There was no mortality. One patient developed bacterial endocarditis and required reoperation after 52 days to replace the tunnel. At follow-up ranging from 11 months to 3 years, 3 patients were in New York Heart Association functional class I, and 6 were in class II. One patient with single ventricle had refractory supraventricular tachycardia after a modified Fontan operation 4 years earlier, which was cured by the total cavopulmonary connection procedure. The essential factors for a good outcome include appropriate surgical indication, avoidance of aortic crossclamping and cardiac arrest, and unobstructed anastomosis between the superior and inferior venae cavae and the pulmonary artery.
|
INTRODUCTION
|
|---|
The use of an extraatrial tunnel is an innovation of the total cavopulmonary connection (TCPC) operation. Experience of this technique in treating 9 cases of complicated congenital heart disease is described.
|
PATIENTS AND METHODS
|
|---|
From April 1997 to February 2000, in 9 consecutive patients requiring TCPC (Table 1
), the procedure was performed with an extraatrial tunnel for palliation of single ventricle (4), double-outlet right ventricle (3), mitral atresia (1), or tricuspid atresia (1). The 3 patients with double-outlet right ventricle had ventricular septal defects too far from the pulmonary and aortic valves to allow intracardiac repair. All 9 patients had symptoms of palpitations on exertion, polypnea, and cyanosis. One frequently adopted a squatting position, and another had a history of hemoptysis. Only one patient had undergone a previous procedure (modified Fontan). Physical examination revealed a grade 3/6 systolic murmur audible at the left or right 2nd to 3rd intercostal spaces. Electrocardiography showed sinus rhythm in all patients, 4 had left axis deviation, 3 had right axis deviation, there was associated right ventricular hypertrophy in 5, right atrial hypertrophy in 2, left ventricular hypertrophy in 2, and left bundle branch block in 1. Diagnoses were confirmed by echocardiography, catheterization, and angiography in all patients (Table 1).
The first 3 patients underwent surgery with moderate systemic hypothermia (25°C to 26°C) and additional local cardiac cooling. The operation was performed on the beating heart under normothermia without aortic crossclamping in the other 6 patients. After a median sternotomy and heparinization, the ascending aorta was cannulated. The superior vena cava (SVC) was cannulated at the level of the azygos vein, and the inferior vena cava (IVC) was cannulated at its commissure with diaphragm. Left atrial drainage was via a catheter inserted into the atrium or the base of the right superior pulmonary vein. Six traction lines were sutured 0.5 cm above the commissure of the SVC and the right atrium (RA). The SVC was ligated and dissected. A transverse incision equal in length to the diameter of the SVC was made in the upper surface of the right pulmonary artery (PA). Absorbable 4/0 polypropylene suture was used for end-to-side anastomosis of the distal end of the SVC and the right PA. The proximal incision was closed 1.5 to 2.0 cm above the cannulation site in the IVC and the surplus length was excised. A 1.5 to 2.0-cm length of Gore-Tex polytetrafluoroethylene tube graft (WL Gore, Elkton, MD, USA) was placed according to the anatomical relationship between the heart and great vessels. For dextroverted hearts or dextrocardia, it formed a reversed "C" shape; otherwise it formed a "C" shape. One end was anastomosed to the distal end of the IVC. An incision was made in the lower surface of the right PA. The incision in the pulmonary valve was sutured. The other end of the tube graft was anastomosed to the PA incision. If the main PA was on the left side of the aorta, it could be cut off and the incisions closed at both ends. The main PA and the left and right PAs were mobilized. The PA was drawn towards the right side and anastomosed to the tube graft. The upper edge of the incision and the commissure between the posterior wall of the IVC and the RA were sutured with a running stitch before anastomosis with the tube graft. Associated cardiac anomalies were corrected appropriately; a patent ductus arteriosus was ligated in 2 cases (patient nos. 1 and 5). A left SVC was anastomosed to the left PA in 1 patient (no. 6). All patients were given anticoagulant therapy with warfarin 0.03 mg•kg-1 daily for one month postoperatively. Subsequently, aspirin 5 mg•kg-1 daily was given orally for 6 months.
|
RESULTS
|
|---|
There was no death in this series. No patient had postoperative arrhythmias. One case (no. 9) of AIII single ventricle had received a modified Fontan operation 4 years earlier and suffered recurrent episodes of refractory supraventricular tachycardia in the previous 2 years, with heart rates of 180 to 200 beats•min-1, which needed electrical defibrillation on each occasion. This did not recur after the TCPC operation. Cardiac catheterization and angiography showed unobstructed anastomosis between the atrium and the PA. Preoperatively, the mean right atrial pressure was 27 mm Hg, with PA pressure of 26 mm Hg. After TCPC, the mean pressure in the extra-cardiac tunnel and PA decreased to 18 mm Hg (Table 1
). One patient (no. 4) developed bacterial endocarditis and underwent reoperation to replace the extracardiac tunnel 52 days after the first procedure. Because the anastomosis orifices of the SVC, IVC, and PA were unobstructed, postoperative cardiac size was normal in each case. The pressures in the PA and each of the cardiac chambers were within the normal range. All patients were followed up for periods ranging from 11 months to 3 years. At follow-up, all patients had good cardiac function and could work or study normally; 3 were in New York Heart Association functional class I, and 6 were in class II.
|
DISCUSSION
|
|---|
In 1988, de Leval and colleagues1 studied the hemo-dynamics of non-valved connections between the vena cava and the PA, and concluded that streamlining was essential to reduce energy losses. They modified the Fontan operation that had been used since 1971, to achieve TCPC.2 The hemodynamics of TCPC are more satisfactory with greatly reduced pressure in the RA due to systemic venous blood draining directly into the PA. Thus, the incidence of supraventricular tachycardia after the Fontan operation can be reduced, as seen in patient no. 9 in this study. The classic partial cavopulmonary connection employed an artificial conduit as a side tunnel in the RA, linking the IVC with the SVC. The right atrial wall served as part of the tunnel, near to the location of the sinoatrial node. However, the long-term effect of high venous blood flow could cause right atrial expansion, and excessive suture line scarring adjacent to the sinoatrial node could cause arrhythmias. In the TCPC technique providing an intraatrial tunnel, cardiac incisions and intracardiac sutures are far from the sinoatrial node, which effectively addresses the complication of tachycardia. Nevertheless, it is still necessary to incise the atrium, thus damaging its structure.3 TCPC with an extracardiac tunnel effectively solves this problem and protects the cardiac tissue because only the IVC and SVC are excised, thereby reducing the incidence of postoperative arrhythmias.4
Another advantage of this operation is that it can be performed on a beating heart without crossclamping the aorta, thus ensuring that the myocardium is perfused with oxygenated blood. It is helpful to maintain heart function in patients with hypoxemia and excessive collateral circulation that may induce systolic and diastolic dysfunction. Unobstructed drainage of venous blood into the PA can be achieved.5 Six traction lines in the SVC were used to ensure an adequate diameter for anastomosis and also prevented it from twisting. We did not completely cut off the IVC in order to prevent spasm due to complete resection, which might cause difficulty in attaching it to the graft. This ensured optimal sizing of the anastomosis, and improved hemodynamics. Coronary sinus blood drained into the atrial chamber under a lower pressure, which enhanced myocardium protection. Further advantages of the extracardiac technique are prevention of tunnel leakage and intraatrial obstruction that can occur with an intracardiac conduit. The extracardiac tunnel is suitable for cases of common atrioventricular valve, intracardiac totally ectopic pulmonary venous drainage, and heart chamber transposition syndromes.6 In this series, cases of dextroverted heart, dextrocardia, atrial trans-position, and common atrioventricular valve all gained effective palliation. Patients treated by the modified Fontan or intracardiac TCPC may have serious complications such as a venous drainage blockage leading to right atrial enlargement, atrial arrhythmias, intraatrial thrombus, and hypertrophy. Under such circumstances, an extracardiac TCPC should be substituted as soon as possible. One case (no. 9) in this study had post-Fontan right atrial hypertension that led to right atrial hypertrophy with consequent frequent arrhythmias. This can be relieved by placing an extraatrial conduit for TCPC.7,8
A disadvantage of TCPC with an extracardiac tunnel is that the prosthesis is made from artificial material and this restricts its application in infants and small children. Autologous pericardium may be used for an extracardiac tunnel that not only has capacity for growth, but also possesses the function of a window. Because the blood flow is slower and there are extensive anastomoses, obstruction is likely to occur. Amodeo and colleagues6 adopted anticoagulant therapy to prevent vessel obstruction. They found the mean diameter of the extracardiac tunnel had reduced by 17.8% ± 7.0% at 6 months postoperatively, but it did not significantly decrease further in a 5-year follow-up. In this series, postoperative application of warfarin anticoagulant therapy was carried out for one month, followed by oral aspirin; no tunnel obstruction occurred. The anastomosis between the IVC, SVC, and right PA leads to chest cavity edema in 20% to 30% of cases.6 PA resistance may increase due to long-term nonpulsatile perfusion, which can influence the development of small PAs and pulmonary arterio-venous fistula. A decrease in right heart hormone may affect electrolyte metabolism and hemodynamics, which needs to be studied further.9
It was concluded from this experience that the essential factors for ensuring a good outcome of TCPC with an extraatrial tunnel include appropriate surgical indication, avoidance of aortic crossclamping and cardiac arrest, and unobstructed anastomosis between the superior and inferior venae cavae and the PA.
|
REFERENCES
|
|---|
-
de Leval MR, Kilner P, Gewillig M, Bull C. Total cavopulmonary connection: a logical alternative to atriopulmonary connection for complex Fontan operations. Experimental studies and early clinical experience. J Thorac Cardiovasc Surg
1988;96:682–95.[Abstract]
-
Fontan F, Baudet E. Surgical repair of tricuspid atresia. Thorax
1971;26:240–8.[Abstract/Free Full Text]
-
Zhang RF, Wang ZW, Sun LZ, Fei CJ, Zhu HY, Gong HD, et al. Total cavopulmonary connection with intra-atrial tunnel. China J Thorac Cardiovasc Surg
1996;12:132–6.
-
Laschinger JC, Redmond JM, Cameron DE, Kan JS, Ringel RE. Intermediate results of the extracardiac Fontan procedure. Ann Thorac Surg
1996;62:1261–7.[Abstract/Free Full Text]
-
Lardo AC, Webber SA, Friehs I, del Nido PJ, Cape EG. Fluid dynamic comparison of intra-atrial and extracardiac total cavopulmonary connections. J Thorac Cardiovasc Surg
1999;117:697–704.[Abstract/Free Full Text]
-
Amodeo A, Galletti L, Marianeschi S, Picardo S, Giannico S, Di Renzi P, et al. Extracardiac Fontan operation for complex cardiac anomalies: seven years' experience. J Thorac Cardiovasc Surg
1997;114:1020–31.[Abstract/Free Full Text]
-
van Son JA, Mohr FW, Hambsch J, Schneider P, Hess H, Haas GS. Conversion of atriopulmonary or lateral atrial tunnel cavopulmonary anastomosis to extracardiac conduit Fontan modification. Eur J Cardio-thorac Surg
1999;15:150–8.[Abstract/Free Full Text]
-
Gundry SR, Razzouk AJ, del Rio MJ, Shirali G, Bailey LL. The optimal Fontan connection: a growing extracardiac lateral tunnel with pedicled pericardium. J Thorac Cardiovasc Surg
1997;114:552–9.[Free Full Text]
-
Sharma S, Goudy S, Walker P, Panchal S, Ensley A, Kanter K, et al. In vitro flow experiments for determination of optimal geometry of total cavopulmonary connection for surgical repair of children with functional single ventricle. J Am Coll Cardiol
1996;27:1264–9.[Abstract]
TOP
ABSTRACT
INTRODUCTION
