Bidirectional Cavopulmonary Shunt in Patients With Anomalies of Systemic and Pulmonary Venous Drainage

Background. Bidirectional cavopulmonary shunt and Fontan repair are now commonly performed in patients with a variety of forms of complex single ventricle, including those with anomalies of systemic or pulmonary venous return. These anomalies are ideally dealt with during bidirectional cavopulmonary shunt, thereby minimizing the complexity of the eventual Fontan procedure.

Methods. Between March 1990 and December 1995, 36 patients with anomalous systemic or pulmonary venous drainage underwent bidirectional cavopulmonary shunt. A combination of anomalous systemic and pulmonary venous drainage was present in 12 patients, whereas 19 patients had anomalous drainage only from the systemic circulation and 5 patients had isolated anomalies of pulmonary venous return. Visceral heterotaxy syndrome was diagnosed in 18 patients. The median age at operation was 11 months, and bidirectional cavopulmonary shunt was the first surgical procedure performed in 10 of these patients. Techniques of repair are described.

Results. There were two early deaths and one bidirectional cavopulmonary shunt was taken down, for mortality and failure rates not significantly different than those for all patients undergoing bidirectional cavopulmonary shunt during this time period (n = 117). At a mean follow-up of 19.9 months, there have been three late deaths and 11 patients have undergone Fontan completion. Actuarial survival was 87% at 1 year and 81% at 3 years. Among all patients undergoing bidirectional cavopulmonary shunt during this time period, neither heterotaxy syndrome nor anomalies of systemic or pulmonary venous return were significantly associated with decreased survival or poor outcome.

Conclusions. Bidirectional cavopulmonary shunt can be performed in patients with anomalous systemic or pulmonary venous drainage, including those with visceral heterotaxy syndrome, with morbidity and mortality rates that do not differ significantly from those achieved in all patients undergoing bidirectional cavopulmonary shunt. In this report, we describe our experience with this group of patients, primarily focusing on outcomes and technical issues that pertain to the use of bidirectional cavopulmonary shunt as a preparatory procedure for the extracardiac conduit Fontan operation.     

丰唐类手术术后血栓栓塞

血栓栓塞是丰唐类手术 (Fontan operation)后的一个严重并发症。血栓形成的原因可能与术后血流状态的改变、内皮细胞功能的丧失及血液粘滞性的改变和凝血系统的异常有关。血栓形成后的表现为腔静脉梗阻、进行性紫绀、心律失常、心肌缺血、肺栓塞、脑梗塞。超声心动图检查心内有无血栓应作为 Fontan术后随访的常规检查 ,经食管超声心动图检查能确诊心内血栓。术后应用抗凝药物可能会减少血栓的发生。     

Clinical Results of the Staged Fontan Procedure in High-Risk Patients

Background. For high-risk Fontan candidates, the introduction of a bidirectional Glenn shunt before total cavopulmonary connection (a two-staged strategy) may extend the indications for the Fontan procedure. The clinical results of the two-staged and one-staged Fontan procedure were thus reviewed and compared.

Methods. Between November 1991 and July 1996, the two-staged strategy was performed in 40 high-risk Fontan candidates with a mean interval of 17.2 months after introducing the bidirectional Glenn shunt (staged group). We considered a young age (<2 years), high mean pulmonary arterial pressure (≥20 mm Hg), high pulmonary vascular resistance (≥3 Wood units), small pulmonary artery (Nakata index <200 mm²/m²), atrioventricular valve incompetence (≥ moderate), distortion of pulmonary artery, anomalous pulmonary venous return, and poor ventricular function as risk factors for the successful completion of Fontan circulation. During the same pe-riod, 68 patients underwent the modified Fontan procedure in a one-step fashion (primary group).

Results. In the staged group after the bidirectional Glenn shunt, the mean pulmonary arterial pressure and ventricular end-diastolic pressure were both found to have decreased significantly to the same level as those in the primary group, whereas the pulmonary artery demonstrated a significantly smaller size than that in the primary group. Operative morbidity was similar in both groups. Operative mortality was also similar and low in both groups (1.5% in the primary group and 0% in the staged group).

Conclusions. A bidirectional Glenn shunt was found to be a useful interim palliation in high-risk Fontan candidates. This two-staged strategy may extend the operative indications for the Fontan procedure.     

A reconsideration of risk factors for the Fontan operation.

We reviewed our experience in 38 patients who underwent a Fontan operation. In the first five patients ages 7.5 to 23 years (mean, 15 years), a conduit was placed from the right atrium to the small right ventricle or the pulmonary artery (PA). The remaining 33 patients, ages 7 months to 14 years (mean, 4.8 years), had a modified Fontan operation with direct systemic venous or right atrial to PA anastomosis. The diagnoses were tricuspid atresia (n = 14), single ventricle (n = 10), hypoplastic right or left ventricle (n = 9), double-outlet right ventricle with inlet ventricular septal defect and pulmonary atresia or stenosis (n = 3), criss-cross ventricles and transposition of the great arteries (n = 1), and atrioventricular canal and anomalous pulmonary venous connection (n = 1). Thirty-two patients had previous surgery. Other procedures included PA banding (n = 7), systemic to PA shunts (n = 25), Norwood operation (n = 3), and a Damus-Kaye-Stansel anastomosis (n = 1), repair of total anomolous pulmonary venous connection (n = 1), a Blalock-Hanlon atrial septectomy (n = 1), and enlargement of a restrictive ventricular septal defect (n = 1). There were four operative deaths (10.5%), three from low cardiac output and one from subaortic obstruction. There were no deaths in patients younger than 3 years of age (n = 13). Subaortic obstruction developed in six of the seven patients who had pulmonary artery banding and resulted in three deaths. In our experience, diagnosis, previous surgery, type of previous operation, PA pressure, and younger age are not risk factors for early or late death. Subaortic obstruction is a major risk factor for late death. Accordingly we now perform a Damus-Kaye-Stansel anastomosis combined with a systemic to PA shunt in those children with excessive pulmonary blood flow who anatomically are likely to develop subaortic obstruction. A modified Fontan operation can be performed any time after 1 year of age and in some patients after 6 months of age, providing the anatomy and physiology of the patient are acceptable.     

Model of complete separation of the hepatic veins from the systemic venous system

Background. In patients undergoing a Fontan operation, partial diversion of the hepatic veins to the pulmonary venous atrium has been tried with various techniques. They failed because of the development of intrahepatic collaterals leading to an unacceptable right-to-left shunting. We postulate that to avoid the formation of intrahepatic collaterals, the totality of the liver has to be drained into the same pressure compartment. We have designed a model of cavopulmonary anastomosis in which a prosthetic conduit reproduces an azygos continuation, associated with the diversion of the totality of the hepatic venous return. This article reports on the early hemodynamics and the fate of the separation of the two venous compartments in long-term survivors.

Methods. Eighteen goats were operated on; the pulmonary artery and hepatic vein pressures were recorded. During month 2, an opacification of the inferior vena cava and the cavopulmonary connection was performed. Between months 6 and 14, another opacification was performed, together with pressure recording at both ends of the conduit.

Results. Postoperatively the pulmonary artery pressure was pulsatile with a mean of 10 mm Hg and the hepatic vein pressure was 0 mm Hg. The first angiogram showed patent tubes with fast progression of the contrast. Throughout the inferior vena cava injection, there was no opacification of the portal or hepatic veins. The late study showed a narrowed conduit in all animals. During the injection, a collateral was injected, feeding into the inferior mesenteric vein. No collateral circulation could be seen draining directly into the liver. The median gradient between the two ends of the conduit was 11 mm Hg.

Conclusions. The isolation of the entire hepatic venous drainage is feasible and efficient for the separation of two pressure compartments. No intrahepatic collaterals are observed with this model at short- or long-term follow-up. The separation of the hepatic venous drainage should persist without collateral circulation as long as the inferior vena cava pressure stays at the levels observed in Fontan circulation.     

Evolution of the Fontan procedure in a single center

Background. Surgical approaches to single ventricle variants include staged, fenestrated, and completed Fontan operations. This study compares outcomes with these modifications of the Fontan operation at a single center.

Methods. Preoperative risk factors and operative results were analyzed by multivariate techniques in 129 patients undergoing modified Fontan operations since March 1988.

Results. Overall early and late mortality was 5.4% and 0.8%, respectively. Before 1993, completed Fontan operation using right atrial to pulmonary artery anastomosis without fenestration was performed in the majority of patients (44 of 58; 76%). During this period, 10 of 17 patients at high risk had completed Fontan with three takedowns. In 1994, the staged hemi-Fontan and modified Fontan with a lateral tunnel anastomosis and with or without small fenestration (2.5 to 4 mm) were introduced. The majority of patients at high risk during this period underwent hemi-Fontan followed by fenestrated Fontan with no takedowns. Late atrial dysrhythmias occurred in 6 patients (4.7%), generally with larger fenestrations or right atrial to pulmonary anastomoses. Three patients (2.3%) had a stroke, 2 with large (≥ 4 mm) fenestrations. Of 38 fenestrations, 32 (84%) closed spontaneously by 1 year. No protein-losing enteropathy occurred. Most patients (118 of 121) were in New York Heart Association class I/II 4.5 years postoperatively. By multivariate analysis, only Down’s syndrome (p < 0.001) predicted early mortality, whereas both Down’s syndrome and a systemic right ventricle decreased late survival (p < 0.006).

Conclusions. Proper selection of patients for modifications of the Fontan procedure resulted in excellent early and late survival with a low incidence of atrial dysrhythmia and stroke. Midterm functional outcomes were excellent.     

Thromboembolism related to a Port-a-Cath device in a patient with cystic fibrosis

The case is described of a potentially life threatening complication relating to the use of a totally implantable venous access device (Port- a-Cath) in a 28 year old patient with cystic fibrosis. The device was inserted in 1990 and used repeatedly for antibiotic therapy without any complications. In 1995, during assessment for double lung transplantation, a 3 cm thrombus was found at the tip of the catheter in the right atrium. Embolisation of the thrombus to the pulmonary arteries occurred after the infusion of recombinant tissue plasminogen activator (rt-PA). Thrombus formation may be associated with totally implantable venous access devices and thromboembolism may occur following the use of thrombolytic agents in the treatment of such thrombosis.


     

Extending the limits for modified Fontan procedures

During the early development of atriopulmonary anastomotic operations (Fontan-Kreutzer), a number of physiologic and anatomical limits were proposed by the Fontan group as selection criteria. Among 167 consecutive patients undergoing modified Fontan procedures from 1973 through 1985, 109 (65%) patients exceeded one or more of the original selection criteria in areas of age, anomalies of systemic or pulmonary venous connection, pulmonary artery distortion, and pulmonary artery pressure. Twenty-six patients had a mean pulmonary artery pressure greater than 15 mm Hg, with 16 operative survivors (62%). Nineteen patients had anomalies of systemic and/or pulmonary venous connection, and 16 survived (84%). There were 44 patients under the age of 4 years, and 26 survived (59%). Twenty-five patients were older than 15 years, and 23 (92%) survived the Fontan procedure. Pulmonary artery distortion, relating to prior palliative operations, was found in 34 patients. Seventeen of these 34 survived a modified Fontan procedure (50%). Twenty-six patients had a pulmonary arteriolar resistance more than 2 Wood units times square meter, and 14 survived (54%), whereas 81 of 93 with a pulmonary arteriolar resistance of less than 2 U X m2 survived (87%). Multivariate analysis showed that pulmonary arteriolar resistance and pulmonary artery distortion had a significant, negative impact on survival, but age and anomalies of systemic and/or pulmonary venous connection did not. Pulmonary artery pressure was not an independent predictor of outcome. The results show that the original criteria may be exceeded in the areas of age and anomalies of pulmonary or systemic venous connection. Pulmonary artery pressure alone should not contraindicate a Fontan procedure if pulmonary arteriolar resistance is low. Pulmonary artery distortion from a prior palliative operation and elevated pulmonary arteriolar resistance increase the risk of a Fontan procedure.     

Staged operation for right isomerism with total anomalous pulmonary venous return: report of a case

A male infant with right isomerism, single ventricle, severe pulmonary stenosis (PS), and total anomalous pulmonary venous return (TAPVR) underwent successful staged Fontan operation. Pulmonary vein drained into right superior vena cava without a stenotic lesion. Common pulmonary venous chamber was also connected with the atrium by a thin bridging vein. Blalock-Taussig shunt was performed at 2-month-old. Because of progressive pulmonary congestion, an anastomosis between common pulmonary venous chamber and the atrium followed 4 days after the first shunt. Bidirectional cavopulmonary shunt was performed 7 months after the second operation. Because of progressive atrioventricular valve regurgitation, repeated bandings of the shunt were required to regulate the pulmonary flow. Total cavopulmonary connection was completed 9 months after the BCPS. Staged operation is a useful strategy to acquire an appropriate pulmonary blood flow for the isomeric heart with TAPVR and severe PS.     

The modified Fontan procedure: morphometry and surgical implications

Background. The modified Fontan procedure for patients with only one well-formed ventricle is now widely regarded as palliative, not curative.

Methods. To improve the surgical management and postoperative follow-up of such patients, a morphometric study of 33 postmortem cases was done.

Results. The three main causes of death were congestive heart failure (82%), arrhythmias (12%), and central nervous system dysfunction (6%). The cross-sectional area of the Fontan anastomosis (FA) relative to the systemic venous area (SVA) and relative to the body surface area (BSA) revealed that the Fontan pathway was often obstructive. The mean FA/SVA index was 73% less than normal: 0.54 ± 0.22, range 0.13 to 0.98. The mean FA/BSA index was 70% less than normal: 143.52 ± 50.01 mm²/M², range 55.09 to 261.67 mm²/M².

Conclusions. The main surgical challenge is to minimize or eliminate prepulmonary stenosis. Although significant postoperative obstruction was often not evident hemodynamically because of small or absent gradients, the presence of important obstruction of the Fontan pathway was clearly revealed by morphometry.     

Use of a Paracorporeal Pneumatic Ventricular Assist Device for Postoperative Cardiogenic Shock in Two Children with Complex Cardiac Lesions

Pneumatic ventricular assist device (VAD) was utilized for cardiogenic shock after intracardiac operation in two children with complex cardiac anomalies based with single ventricle. In the first case (a 10-year-old), after a modified Fontan operation, VAD was placed between the functional left atrium and ascending aorta, serving as a "artificial single ventricle" with neither pumping chamber nor artificial support in the right side of the heart. The systemic circulation was maintained by keeping relatively high central venous pressure. In another child (a 3-year-old) who underwent repair of incompetent atrioventricular valve leaving intracardiac lesions, VAD was placed between the common atrium and ascending aorta, serving as a pump for both pulmonary and systemic circulation with regulation of pulmonary blood flow through an aortopulmonary Gore-Tex shunt. The circulatory assist with VAD was utilized for 5 and 6 days, respectively. Although weaning from the device was not feasible in both patients because of the pulmonary dysfunction, these experience showed the possible use of VAD for cardiogenic shock after surgery in patients with complex cardiac anomalies.     

Direct tricuspid closure versus atrial partitioning in Fontan operation for complex lesions

Thirty-three patients with complex lesions undergoing the Fontan operation needed either direct tricuspid closure (group 1, 14 patients) or atrial partitioning (group 2, 19 patients). In group 1, the tricuspid patch was sutured to the annulus leaving the coronary sinus draining to the systemic venous atrium. In group 2, atrial partitioning was accomplished with either a Dacron or a polytetrafluoroethylene patch, leaving the coronary sinus draining to the pulmonary venous atrium. Intraoperative distention of the left side was used to check for residual defects. In group 1, complete heart block developed in 5 patients (36%) and patch disruption, in 4 patients (29%). There were 3 late deaths (21%), which were due to sudden death, sepsis caused by Candida, and liver failure. In group 2, no patient had heart block, and patch disruption developed in 1 patient (5%). There was 1 early death (5%) and 2 late deaths (11%), which were due to sepsis caused by Candida and renal failure. Our experience suggests that atrial partitioning is a better approach than direct tricuspid patch closure in patients with complex lesions undergoing the Fontan operation.     

A case of tumor thrombus in the right atrium after multimodal treatment of testicular tumor

A case was reported concerning a successful removal of tumor thrombus extending into the right atrium through the left brachiocephalic vein and the superior vena cava. The patient was a 34-year-old man who underwent a left inguinal orchiectomy for immature teratoma of testis in June 1987. The operation was followed by another three operations for excision of lymph node metastases and five courses of cisplatin based combination chemotherapy. In December 1988, the chest CT scan film revealed filling defect in the superior vena cava and the right atrium. Thrombus was detected using echocardiography and angiography. He had no symptom, but multiple pulmonary infarcts were also detected. In February 1989, the operation was performed by means of cardio-pulmonary bypass. A soft yellowish thrombus attached to the left venous angle was removed with resection of the left brachiocephalic vein. Microscopic findings revealed that the thrombus was metastatic testicular teratoma. With further treatment after the operation, he has been disease-free for 14 months now. We conclude that in this case aggressive surgical management following chemotherapy had great value to control the disseminated testicular tumor.     

Thromboembolism originated from the pulmonary artery stump after Fontan operation

Cerebral thromboembolism is a rare but serious complication after Fontan operation. This is the report of a patient who underwent a successful intracardiac thrombectomy for cerebral thromboembolism after Fontan operation. A 2-year-old girl was referred to us with the diagnosis of tricuspid atresia without pulmonary stenosis, normally related great arteries, and a ventricular septal defect. Although she underwent a successful Fontan operation and division of the main pulmonary artery, she developed a cerebrovascular event at 3 weeks after the operation. Echocardiography demonstrated a large thrombus within the residue of the main pulmonary artery, and suggested that the thrombus had migrated into the systemic circulation by way of the ventricular septal defect. At 2 weeks after the cerebrovascular event, she underwent thrombectomy and excision of the pulmonary valve. Although she has developed slight left-sided hemiparesis, she is leading a normal life at 1 year after the operation.     

Thromboembolism originated from the pulmonary artery stump after Fontan operation.

Cerebral thromboembolism is a rare but serious complication after Fontan operation. This is the report of a patient who underwent a successful intracardiac thrombectomy for cerebral thromboembolism after Fontan operation. A 2-year-old girl was referred to us with the diagnosis of tricuspid atresia without pulmonary stenosis, normally related great arteries, and a ventricular septal defect. Although she underwent a successful Fontan operation and division of the main pulmonary artery, she developed a cerebrovascular event at 3 weeks after the operation. Echocardiography demonstrated a large thrombus within the residue of the main pulmonary artery, and suggested that the thrombus had migrated into the systemic circulation by way of the ventricular septal defect. At 2 weeks after the cerebrovascular event, she underwent thrombectomy and excision of the pulmonary valve. Although she has developed slight left-sided hemiparesis, she is leading a normal life at 1 year after the operation.     

Simple Left Atrial Procedure for Chronic Atrial Fibrillation Associated With Mitral Valve Disease

Background. A computerized 48-channel mapping system was used to investigate the characteristics of an atrial epicardial electrogram during chronic atrial fibrillation (AF) in patients with solitary mitral valve disease. We have devised a simple left atrial procedure to eliminate the chronic AF during a mitral valve operation.

Methods. Using this mapping system, we performed intraoperative atrial mapping in 11 patients with chronic AF associated with mitral valve disease. The AF duration ranged from 0.4 to 15 years (mean, 8.0 ± 4.5 years). A simple surgical ablation of the AF on the left atrium only was performed during the mitral valve operation.

Results. The mean AF cycle length of the atria ranged from 129 to 169 milliseconds in the right atrium and from 114 to 139 milliseconds in the left atrium. The mean AF cycle length of the left atrium was shorter than that of the right atrium. Regular and repetitive activation was found in the left atria of 7 of 11 patients. The AF disappeared in all patients immediately after the operation, and 10 of these patients continued to have a sinus rhythm postoperatively (AF-free rate, 91%).

Conclusions. Computerized intraoperative mapping revealed a shorter mean AF cycle length in the left atrium. A simple left atrial procedure was effective in eliminating chronic AF associated with solitary mitral valve disease.     

The Fontan procedure in the absence of the interatrial septum. Failure of its principle?

The Fontan principle, defined as a procedure in which the right ventricle is bypassed in order to convey desaturated venous blood from the right atrium to the lungs, is presently applied for a wide variety of congenital heart malformations including those in which there is no suitable ventricular pumping chamber. Recently, the procedure has also been advocated for complex malformations that require atrial septation or intra-atrial rerouting. The present report evaluates our experience in four patients with such complex malformations. Three had a complete form of atrioventricular septal defect with double-outlet right ventricle and one patient had left atrioventricular valve atresia. The common atrium was morphologically right in two patients and morphologically left in one. In each of these instances anomalous pulmonary venous connections were present, together with abnormal systemic venous connections. The results were unsatisfactory. Three of the four patients died. The only survivor had no pulmonary or systemic venous abnormalities. Severe impairment of pulmonary blood flow was one of the most important postoperative complications. The findings suggest that the complexities of rerouting the blood within the atria play an important role. The excess proportion of prosthetic material to atrial myocardium may result in excessive loss of contractile atrial myocardium and, probably equally significant, in a complex intra-atrial geometry of pathways that may cause a critical pressure gradient. The results clearly show that with an expanding horizon of the application of the Fontan principle, new pitfalls may arise which presently appear to be the prevailing factors limiting its success.     

Late Complication of Classic Fontan Operation: Giant Right Atrial Thrombus and Massive Pulmonary Thromboembolism

Abstract Thrombus formation can be a significant cause for morbidity and mortality after Fontan operation. Intracardiac thrombus formation can lead to chronic pulmonary embolic disease if formed on the right side, or stroke, if on the left side of the heart. Right‐sided embolism may result in ventilation/perfusion mismatch or elevation of pulmonary vascular resistance, both of which may seriously hamper cavopulmonary physiology. We report the case of a 22‐year‐old patient, with past history of classic Fontan procedure performed at the age of six to palliate a single‐ventricle tricuspid atresia, who presented with a massive pulmonary embolism and hemodynamic instability. Due to his critical status, mechanical fragmentation of the clot using the angiography catheter was started, followed by a local catheter‐directed infusion of urokinase. This case demonstrated that pharmacomechanical thrombolysis therapy with a standard Pig‐tail catheter and thrombolytic therapy with urokinase is secure, effective, and appropriated to manage heart chamber and pulmonary arterial thrombosis in patients with congenital heart disease.     

Rebound Pulmonary Hypertension After Inhalation of Nitric Oxide

Background. We describe the hemodynamic response to initiation and withdrawal of inhaled nitric oxide (NO) in infants with pulmonary hypertension after surgical repair of total anomalous pulmonary venous connection.

Methods. Between January 1, 1992, and January 1, 1995, 20 patients underwent repair of total anomalous pulmonary venous connection. Nine patients had postoperative pulmonary hypertension and received a 15-minute trial of inhaled NO at 80 parts per million. Five of these patients received prolonged treatment with NO at 20 parts per million or less.

Results. Mean pulmonary artery pressure decreased from 35.6 ± 2.4 to 23.7 ± 2.0 mm Hg (mean ± standard error of the mean) (p = 0.008), and pulmonary vascular resistance decreased from 11.5 ± 2.0 to 6.4 ± 1.0 U · m² (p = 0.03). After prolonged treatment with NO, pulmonary artery pressure increased transiently in all patients when NO was discontinued.

Conclusions. After operative repair of total anomalous pulmonary venous connection, inhaled NO selectively vasodilated all patients with pulmonary hypertension. Withdrawal of NO after prolonged inhalation was associated with transient rebound pulmonary hypertension that dissipated within 60 minutes. Appreciation of rebound pulmonary hypertension may have important implications for patients with pulmonary hypertensive disorders when interruption of NO inhalation is necessary or when withdrawal of NO is planned.     

The failing Fontan with atrial flutter: a successful surgical option

Two successful cases of eliminated atrial flutter and improved clinical status for Fontan patients are presented. An operation combining introduction of an extracardiac conduit for the Fontan connection, to direct all systemic venous blood away from the atrium, and atrial pathway division and cryoablation, is a useful surgical option for failing Fontan patients.