Physiological rationale for a bidirectional cavopulmonary shunt. A versatile complement to the Fontan principle

The original Fontan procedure included a classic superior vena cava-to-right pulmonary artery (Glenn) shunt. Subsequent experience demonstrated that this anastomosis was not essential and was an unnecessary commitment of the larger right pulmonary circulation to the smaller blood volume of the superior vena caval return. With application of the Fontan principle to more complex cardiac malformations, there has been a reconsideration of possible benefits of a cavopulmonary shunt in selected patients. A modified shunt from the divided end of the superior vena cava to the side of the undivided right pulmonary artery utilized in 21 patients is described. This shunt is designed to allow bidirectional pulmonary arterial distribution of both superior vena caval inflow and right atrial outflow after completion of the Fontan procedure. Twelve patients had the bidirectional shunt performed prior to a Fontan operation; five of these had a subsequent atriopulmonary connection and seven await operation. Eight patients had construction of this shunt at the time of their Fontan procedure. One patient had a bidirectional shunt constructed following atriopulmonary anastomosis to help relieve right atrial outflow obstruction. Two patients with univentricular heart undergoing simultaneous Fontan procedure and a bidirectional shunt died while in the hospital. The remaining 19 patients have been followed up for 2 months to 9 years with one late sudden death at 9 years. There have been no bidirectional cavopulmonary shunt failures, stenoses, kinks, or recognized pulmonary arteriovenous malformations. Postoperatively, eight patients had assessment of pulmonary distribution of shunt blood flow by angiography. Seven of these patients were also evaluated by radionuclide angiography. Superior vena caval blood flow via the bidirectional cavopulmonary shunt tended to be greater to the right lung, but bilateral pulmonary flow was documented in all but one patient. After Fontan operation, six of seven patients tested also demonstrated bilateral distribution of atriopulmonary flow. We concluded from our experience that this modified shunt provides excellent relief of cyanosis, allows bidirectional pulmonary distribution of both superior vena caval return and also the right atrial blood flow after atriopulmonary connection, and may be done before, with, or after a Fontan procedure and is compatible with all currently recommended modifications. Perioperative hemodynamic adjustments to the Fontan procedure may be improved by reducing atrial volume, and this may also be of potential benefit in the long-term adaptation to Fontan physiology by minimizing atrial distention.     

Novel surgical approach 'intrapulmonary-artery septation' for Fontan candidates with unilateral pulmonary arterial hypoplasia or pulmonary venous obstruction

It is difficult to manage patients with single ventricular physiology and unbalanced pulmonary arteries. Since 1998, we started a novel approach [Intrapulmonary-artery Septation (IPAS)] to improve the result for those with severe unbalanced pulmonary arteries consisting of a well-grown pulmonary artery and an inadequately-grown pulmonary artery. The inadequately-grown pulmonary artery includes severe pulmonary arterial hypoplasia and pulmonary venous obstruction. This approach is based on the following concepts: (1) A reliable blood source should be secured to recover the inadequately-grown pulmonary artery; (2) Wasteful volume-load should be prevented for the heart; (3) Long stenosis or non-confluence of pulmonary artery should be avoided. IPAS primarily consists of (A) a Glenn shunt; (B) a systemic-pulmonary artery shunt; and (C) a septation-patch. Both (A) and (B) are adjoined on a well-grown pulmonary artery, and (C) is placed between (A) and (B). PAS brings two separate blood flows of a Glenn shunt to the well-grown side and SPS on the inadequately-grown side. IPAS was performed in 20 patients. Seventeen reached the Fontan operation. Eleven underwent postoperative catheterization and seven had acceptable-balanced pulmonary blood flow distribution. IPAS can pilot more complicated cases having severe unbalanced pulmonary arteries to the Fontan circulation.     

Bidirectional cavopulmonary shunts: clinical applications as staged or definitive palliation

A standard Glenn anastomosis between the superior vena cava and the right pulmonary artery has been the accepted mode of treatment for patients with complex cyanotic congenital heart disease. We report our experience in 18 patients with such disease who underwent a bidirectional cavopulmonary shunt because of increasing cyanosis and growth cessation. All patients were considered less than "ideal" candidates for a Fontan procedure. We divided the patients into two groups: group 1 had azygos continuation and group 2 did not. Fourteen patients required hypothermic cardiopulmonary bypass. Bidirectional pulmonary blood flow was achieved in all patients. Only 1 death occurred (group 2). The improvement in oxygen saturation and overall clinical condition of these patients, together with the low mortality and morbidity, is encouraging. However, long-term follow-up is mandatory for a comprehensive evaluation of this surgical approach as definitive palliation or as a first stage for a Fontan operation.     

Surgical treatments of nonconfluent pulmonary arteries with congenital cardiac defects]

Pulmonary artery angioplasty or reconstruction was performed in seven patients with nonconfluent pulmonary arteries and congenital cardiac defects. Age of these patients were ranged from 6 months to 41 years old. Five of them had pulmonary truncal atresia and complex cardiac anomalies. Two of these five patients demonstrated nonconfluent pulmonary arteries due to deformities at ductal insertion of pulmonary arteries. Three patients had had previous systemic to pulmonary artery shunt operations which caused pulmonary artery distortions. Other two patients had intrapulmonary arterial obstructions due to pulmonary artery thrombosis. Patch pulmonary artery plasty was carried out in three patients, dilatation of severe stenotic pulmonary artery was done in one patient simultaneously with pulmonary valvotomy. Central shunt operation was added in one patient with the pulmonary artery which was unable to be reconstructed. Last two patients underwent intrapulmonary artery reconstruction with the rolled pericardial graft. Hospital death occurred in one patient with unproperly increased pulmonary blood flow by central shunt. Average follow-up period of these six survivors after operation was 1.4 +/- 0.8 years. As definite repairs, two patients had Fontan operation, two patients had right ventricle to pulmonary artery reconstruction. And remaining two patients are still to be followed until sufficient growth of pulmonary artery suitable for Fontan operation.     

Extracardiac Fontan operation without cardiopulmonary bypass

AIM: The avoidance of cardiopulmonary bypass and aortic cross-clamping in patients possessing single ventricular physiology has potential advantages including preservation of ventricular and pulmonary functions; early extubation, decreased incidence of pleural effusions and decreased requirement of inotropic agents and blood products. In this study, we assessed the postoperative outcome of patients who have undergone extracardiac Fontan operation performed without cardiopulmonary bypass. METHODS: Between March 1999 and August 2002, 10 consecutive patients (6 males and 4 females) underwent extracardiac Fontan operation without cardiopulmonary bypass. The age of patients ranged between 1.5 to 12 (5.2+/-3.1) years. All the patients requiring any intracardiac intervention were excluded from the study. Previous operations of the patients were modified Blalock-Taussig shunt procedure in 3 patients, bidirectional cavopulmonary shunt operation in 2 patients and pulmonary arterial banding in 1 patient. All operations were performed without cardiopulmonary bypass. Bidirectional cavopulmonary anastomosis was performed by using a transient external shunt constructed between the superior vena cava and right atrium. An appropriate sized tube graft was anastomosed to the inferior surface of right pulmonary artery. Finally, inferior vena cava to tube grafts anastomosis was performed with the aid of another external shunt constructed between inferior vena cava and right atrium. During the procedure central venous pressure, blood pressure and arterial oxygen saturation levels were continuously monitored and recorded. RESULTS: The mean intraoperative Fontan pressure was 16.1+/-2.75 mmHg. Intraoperative fenestration was required in 4 patients with a Fontan pressure above 18 mmHg. There were no intra and postoperative deaths. Three patients required mild doses of inotropic support during the postoperative period. All patients were weaned off mechanical ventilation within 24 h. The mean arterial oxygen saturation raised from 74.5+/-4.2% to 93.5+/-2%. Arterial oxygen saturation was 95+/-0.6% in 6 patients without fenestration and 91.2+/-0.5% in 4 patients with fenestration (P=0.001). All patients were in sinus rhythm postoperatively. Only 2 patients required blood transfusion. Two patients suffered from prolonged pleural effusion (more than 7 days). The mean intensive care unit and hospital stay periods were 3.3+/-1.5 and 15.4+/-5.3 days, respectively. CONCLUSIONS: The extracardiac Fontan operation performed without cardiopulmonary bypass provides good results in short and midterm follow-up periods with improved postoperative hemodynamics.     

Modified fontan operation

From November 1988 to October 1991 30 patients underwent a total extracardiac right heart bypass for complex cardiac anomalies by means of bidirectional cavopulmonary anastomosis and interposition of a conduit from the inferior vena cava to the pulmonary artery. Mean age at surgery was 6.4 years and mean weight 19.2 kg. There was 1 hospital death (3%) due to a borderline indication for a Fontan operation. 2 patients had further surgery: In 1 the repair was taken down due to the stenosis of the left pulmonary artery and the patient was left with a bidirectional cavopulmonary anastomosis only, the second patient required a revision of the cavopulmonary anastomosis due to a stenosis of the superior vena cavaright pulmonary artery junction. There were no late deaths and the survivors are in good clinical condition a mean of 15.1 months after the operation. We propose this technique as an alternative surgical option in candidates for a Fontan operation in whom atrial septation is hazardous including those with 1) hypoplasia or atresia of the left atrio-ventricular valve, 2) common atrioventricular valve, 3) anomalies of systemic and/or pulmonary venous return, or 4) auricular juxtaposition.     

Surgical Management of Univentricular Heart with Total Anomalous Pulmonary Venous Drainage and Intrapulmonary Vertical Vein

Abstract   We report a patient with univentricular heart, heterotaxy syndrome with total anomalous pulmonary venous connection, and an intrapulmonary vertical vein draining into the left superior vena cava who underwent a successful bidirectional Glenn shunt without cardiopulmonary bypass. A polytetrafluoroethylene tube interposition graft was used between the superior vena cava and the pulmonary artery. This condition is unusual and physiologic palliation, rather than anatomic correction as described in this report, may be appropriate for managing this condition. (J Card Surg 2010;25:84-86)     

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.     

Total cavopulmonary shunt operation in complex cardiac anomalies. A new operation

Four patients with presently uncorrectable cyanotic cardiac anomalies underwent a new operation, "total cavopulmonary shunt operation" or "total right heart bypass operation." These anomalies included single ventricle, single atrium, common atrioventricular valve with or without regurgitation, pulmonary stenosis, and most important, absent inferior vena cava with azygos or hemiazygos continuation. All patients had had previous systemic-pulmonary shunts. The new operation consisted of end-to-side anastomosis between the superior vena cava with azygos or hemiazygos continuation and the confluent pulmonary artery, division or ligation of the pulmonary artery trunk, and replacement of the common atrioventricular valve when regurgitation was present. Thus total venous return, except for hepatocardiac venous and coronary sinus flow, drains directly into the pulmonary artery, bypassing the right atrium and ventricle. Three patients survived the operation, and two of the three patients are now alive 4 years, 8 months and 2 years, 6 months after the operation. The two long-term survivors are in significantly improved condition, both clinically and hemodynamically. We believe that this new operation is promising in the treatment of the otherwise uncorrectable complex cardiac anomalies associated with azygos or hemiazygos continuation of the inferior vena cava. A longer follow-up is certainly mandatory before final conclusions can be reached.     

Partial biventricular repair for double-outlet right ventricle with left ventricular hypoplasia

The presence of left ventricular hypoplasia in double-outlet right ventricle may increase the risk of biventricular repair and Fontan procedures. The hypoplastic left ventricle of an 11-year-old girl with complex double-outlet right ventricle was successfully incorporated in a modified biventricular repair by Dacron patch closure of the ventricular septal defect, diversion of venous return of the inferior vena cava to the mitral valve with an intraatrial baffle, insertion of a left ventricular apex to pulmonary artery valved aortic homograft, and diversion of residual systemic venous return directly to the lungs with a bidirectional superior vena cava to pulmonary artery shunt. Postoperatively, the systemic venous atrial pressure was 6 mm Hg and the pulmonary artery pressure was 14 mm Hg. This method is proposed as a partial biventricular repair hemodynamically superior to the Fontan procedure, although aortic homograft revision may be required in the future.     

Protein-losing enteropathy after Fontan operation

Generalized edema resulting from severe protein-losing enteropathy occurred in three patients 12, 15, and 17 months after the Fontan operation. One patient originally had tricuspid atresia and the other two, univentricular heart disease. At operation a conduit had been inserted between the right atrium and pulmonary artery. Apart from the protein loss, the patients were in good health. The cardiac catheterization data obtained 0.8 to 2.4 years (median 1.3 years) after operation in the three patients with protein-losing enteropathy were compared with those of 18 patients in whom Fontan's operation had been performed because of tricuspid atresia (eight patients) or univentricular heart disease (10 patients). All had atriopulmonary connections. The mean right and left atrial pressures and systemic blood flows measured by dye dilution in the patients with and without protein-losing enteropathy did not differ. However, the patients with protein-losing enteropathy had a higher diastolic right atrial pressure. Since maximal antegrade flow in the superior vena cava after Fontan's operation occurs during atrial diastole, these observations suggest that an increase in diastolic right atrial pressure may result in protein-losing enteropathy because of impairment of blood flow and therefore congestion in the superior vena cava, subclavian vein, and thoracic duct.     

Peri-operative comparison of different transient external shunt techniques in bidirectional cavo-pulmonary shunt.

OBJECTIVE: In patients with functional single ventricular physiology, the avoidance of cardiopulmonary bypass offers many advantages including earlier extubation, decreased necessity of inotropic support, improved hemodynamical status and reduced likelihood of post-operative prolonged pleural effusion. We believe that the bidirectional cavopulmonary anastomosis operations may be performed with transient external shunt techniques. The purpose of this prospective study is the peri- and post-operative comparison of different transient external shunt methods used in bidirectional cavopulmonary shunt operations. METHODS: Between years 1997 and 2000, 30 patients have undergone bidirectional cavo-pulmonary shunt operation by using three different types of external shunt. The mean patient age was 13 months (range, 3 months-3 years). Previous operations had been performed in ten patients (33%). All patients were divided into three groups according to type of external shunt used. In group A (ten patients), the transient external shunt was constructed between superior vena cava and right atrium by uniting two standard venous cannulas with a Y-connector. In group B (ten patients), the external shunt was performed with a single short venous cannula constructed between superior vena cava and right atrium. In group C (ten patients), the external shunt was constructed between superior vena cava and left pulmonary artery by using a single short venous cannula. During operation, central venous pressure (CVP), arterial O(2) saturation and mean arterial blood pressure were recorded continuously. RESULTS: All operations are completed without the establishment of cardiopulmonary bypass. Hospital mortality was 3.3%. One patient in group A died because of low cardiac output at the end of postoperative day 2. All patients were extubated within 4h. In groups A-C mean superior vena caval pressures were measured 28, 24 and 21 mmHg, respectively during superior vena cava-right pulmonary artery anastomosis. In both groups A and B patients, arterial O(2) saturation decreased to a minimum 53+/-2 and 53+/-2%, respectively during the operation. In the group C, minimum arterial O(2) saturation was measured 82+/-2%. Although mean arterial pressure decreased in all groups during clampage; in group C patients, this drop is not significant. CONCLUSION: Based on the study presented here, bidirectional cavo-pulmonary anastomosis can be carried out by using different types of transient external shunt. The best hemodynamical condition and arterial O(2) levels were achieved with the shunt constructed between superior vena cava and left pulmonary artery.     

New approach to the surgical management of pulmonary arteriovenous malformations after cavopulmonary anastomosis

The development of pulmonary arteriovenous malformations after cavopulmonary bypass in patients with congenital heart disease is well documented. We report successful management of pulmonary arteriovenous malformations after cavopulmonary bypass in a patient with an interrupted inferior vena cava (IVC) and multiple hepatic veins utilizing an extracardiac conduit from the hepatic veins to the hemiazygous continuation of the interrupted IVC. This technique, performed without circulatory arrest or an atriotomy, may limit morbidity associated with intracardiac procedures in patients with single ventricle morphology. Furthermore, this case suggests an alternative technique for completion Fontan in patients with an interrupted IVC and multiple hepatic venous drainage.     

Partial anomalous pulmonary venous connection to the superior vena cava

We describe the surgical technique of reimplantation of the right superior pulmonary vein into the left atrium in 2 patients with partial anomalous pulmonary venous connection to the superior vena cava without atrial septal defect. A right axillary minithoracotomy is done through the fourth intercostal space. The pulmonary vein is detached from its origin in the superior vena cava. This is sutured with 6-0 reabsorbable polydioxanone suture (Ethicon, Somerville, NJ). A lateral clamp is applied to the left atrium, and the pulmonary vein is reimplanted. The patient is extubated in the operating room. Neither cardiopulmonary bypass nor blood transfusion was required. It is simple, safe, and reproducible.     

New technique of right heart bypass in congenital heart surgery with autologous lung as oxygenator

BACKGROUND: Modifications have been made in cardiopulmonary circuit to reduce the inflammatory deleterious effects and cost. We present our experience of one such right heart bypass (RHB) circuit utilizing autologus lung as oxygenator. METHODS: From September 2001 to December 2002, 15 patients underwent congenital heart surgery with this technique. Bypass circuit consisted of a reservoir and a roller pump along with a cardiotomy sucker. The left pulmonary artery and main pulmonary artery were used for arterial return, and venous drainage was achieved with innominate vein cannulation. Inferior vena cava cannulation was performed when needed. Thirteen patients underwent bidirectional Glenn shunt surgery (12 to 24 months, 6 to 10 kg). One patient (26 years old) underwent central shunt with enlargement of confluence and left pulmonary artery. Another patient (18 months old) underwent 1.5 ventricle repair. RESULTS: There were no hospital deaths. Mean flow achieved on RHB was 0.57 +/- 0.3 L/min/m(2), central venous pressure was 3.3 +/- 1.8 mm Hg (0 to 7 mm Hg), and mean arterial pressure could be maintained satisfactorily in all patients (54 +/- 14 mm Hg). Mean RHB time was 54 +/- 14 min. Mean central venous pressure was 10.1 +/- 2.4 mm Hg after procedure and saturation was similar to that on (RHB 88% +/- 8%). The mean amount of drainage was 9.1 +/- 4.2 mL/kg per 24 hours. Avoiding an oxygenator and reducing the number of tubings achieved a combined cost savings of 40% for all procedures. CONCLUSIONS: Right heart bypass is a simple, safer, and less expensive alternative to conventional cardiopulmonary bypass. This technique allows effective decompression of superior vena cava, adequate oxygenation, and predicts saturation after Glenn shunt. It can also be applied for central shunts and pulmonary artery reconstructions with cost containment.     

心外管道全腔静脉-肺动脉连接术的疗效

目的总结心外管道全腔静脉-肺动脉连接术(total cavopulmonary connection,TCPC)的经验,探讨手术适应证、手术设计、手术方法以及治疗效果.方法回顾分析29例心外管道TCPC患者的临床资料,平均年龄10岁,病种包括三尖瓣闭锁9例,左室型心室双入口9例,二尖瓣闭锁3例,右心室双出口合并左心室发育不良5例,矫正型大动脉转位解剖右心室发育不良3例.全部在体外循环下手术,12例采用心脏停搏,17例在并行转流心脏不停跳下手术.结果早期22例中死亡5例,后7例无死亡;随访3个月～10年,无晚期死亡.发生低心排血量综合征12例,乳糜胸11例.结论心外管道TCPC用于较大儿童或成人患者与其他Fontan类手术比较,临床长期效果较好.但应严格掌握手术适应证,合理的手术设计和术中细致操作,有危险因素时增用开窗术以及围术期严密观察和处理是提高手术近、远期治疗效果的关键.     

Extracardiac total cavopulmonary connection using a Y-shaped graft

We report on 17-year-old Fontan candidate with a seerely distorted central pulmonary artery (PA) who underwent a successful extracardiac total cavopulmonary connection using a Y-shaped bifurcated graft. A nonanatomic pathway from the inferior vena cava to the left PA was constructed and positioned anterior to the ascending aorta. The other arm was used as a conduit between the inferior vena cava and the right PA. All procedures were performed under temporary venous bypass without cardiopulmonary bypass.     

Unusual course of a pulmonary artery catheter through a persistent superior vena cava]

We report the unusual course of a pulmonary artery catheter through a persistent left-sided superior vena cava. After left subclavian vein cannulation and downward left-sided paramediastinum course, the Swan-Ganz catheter enters the right pulmonary artery. Haemodynamic monitoring was consistent with the diagnosis of septic shock developed by this 56-year-old woman, after cephalic duodenopancreatectomy. Persistent left-sided superior vena cava occurs in 0.5% of the population and 5-10% of patients with congenital heart diseases. It drains into the right atrium through the coronary sinus in 92% of cases and is associated with an absent right superior vena cava in 20% of cases. The left-sided superior vena cava persists when the caudal part of the left anterior cardinal vein does not degenerate. A persistent left superior vena cava may be medically relevant during implantation of pacemaker leads or radiofrequency ablation, during cardiac surgery for placement of a retrograde coronary sinus cardioplegia catheter and during transjugular intrahepatic portosystemic shunt placement.     

The infant with single ventricle and excessive pulmonary blood flow: results of a strategy of pulmonary artery division and shunt

BACKGROUND: The infant with a single ventricle and excessive pulmonary blood flow requires early protection of the pulmonary vascular bed to insure suitability for a subsequent Fontan procedure. The traditional approach, pulmonary artery banding, has had disappointing results. We have pursued an alternate strategy: division of the pulmonary artery, and placement of a systemic-to-pulmonary artery shunt. Potential sites of systemic outflow tract obstruction are simultaneously bypassed, by either a Damus-Kaye-Stansel, or modified Norwood procedure. METHODS: From January 1996 to June 2001, 22 infants were treated by this strategy. Patients with hypoplastic left heart syndrome were excluded. Median age was 18 days (range 2 days to 6 months). In addition to pulmonary artery division and shunt, 3 of 22 patients underwent a Damus-Kaye-Stansel procedure, and 13 of 22 patients underwent a modified Norwood procedure. RESULTS: There were no operative deaths, and one late death. Actuarial survival beyond 30 months was 90%. At follow-up catheterization in 22 patients, median transpulmonary gradient was 7 mmHg (range 4 to 18), and median pulmonary vascular resistance 1.9 Wood units (range 0.9 to 3.3). Twenty-one patients have undergone a subsequent bidirectional superior cavopulmonary connection, and 6 a Fontan procedure, with no deaths. No patient developed subaortic stenosis, or aortic arch obstruction. Neoaortic insufficiency was none or trivial in 12 patients, mild in 3, and moderate in 1. CONCLUSIONS: In patients with a functional single ventricle and excessive pulmonary flow, a strategy of pulmonary artery division and shunt, along with prophylactic bypass of systemic outflow obstruction, carries low operative and midterm mortality. It provides consistent protection of the pulmonary vascular bed, avoids subaortic stenosis and aortic arch obstruction, minimizes neoaortic insufficiency, and ensures suitability for progression along a Fontan pathway. These results provide a comparison for alternate strategies, including pulmonary artery banding.     

Anesthetic management of an infant with pulmonary atresia and ventricular septal defect accompanied by excess pulmonary blood flow for systemic-pulmonary shunt operation]

A 6-month-old infant had pulmonary atresia with ventricular septal defect (PA + VSD) accompanied by excess pulmonary artery flow via major aortopulmonary collateral artery, underwent aortopulmonary shunt with artificial graft under midazolam-fentanyl anesthesia. After the administration of protamine, arterial oxygen saturation gradually decreased. We suspected that hypotension and decrease in cardiac output induced by protamine caused the decrease in pulmonary blood flow via central shunt. It is suggested that pulmonary blood flow should be maintained by using an inotropic agent and a selective pulmonary arterial dilator such as prostaglandin E1 in a patient with PA + VSD after the institution of aorto-pulmonary shunt, because the patient with excess pulmonary flow has been reported to have high pulmonary resistance due to pulmonary abnormalities such as stenosis and thrombosis.