Hemi-Fontan operation in surgery for single ventricle: a preliminary report

Five decades of Fontan palliation: What have we learned? What should we expect?

The Fontan procedure is the final palliative surgery in a series of staged surgeries to reroute the systemic venous blood flow directly to the lungs, with the ventricle(s) pumping oxygenated blood to the body. Advances in medical and surgical techniques have improved patients' overall survival after the Fontan procedure. However, Fontan-associated chronic comorbidities are common. In addition to chronic cardiac dysfunction and arrhythmias, complications involving other organs such as the liver, lungs, intestine, lymphatic system, brain, and blood frequently occur. This narrative review focuses on the immediate and late consequences in children, pregnant women, and other adults with Fontan circulation. In addition, we describe the technical advancements that might change the way single-ventricle patients are managed in future.

Incidence and Management of Thrombotic and Thromboembolic Complications Following the Superior Cavopulmonary Anastomosis Procedure: A Literature Review

The objective of this literature review was to estimate the incidence of thrombosis and thromboembolism associated with the superior cavopulmonary anastomosis (SCPA) procedure and its variants and to examine current thromboprophylaxis regimens utilized. MEDLINE and EMBASE were searched from inception to August 2017 for all prospective and retrospective cohort studies explicitly reporting incidence of thrombosis, thromboembolism, or shunt occlusion in neonates, infants, and children undergoing 1 or more variants of the SCPA procedure. End points included thrombotic events and thromboembolic events (strokes and pulmonary embolisms) as primary outcomes, and overall mortality as a secondary outcome, at the last available follow-up time point. Of 1303 unique references identified, 13 cohort studies were deemed eligible. Reported incidence of thrombosis and thromboembolic events ranged from 0% to 28.0% and from 0% to 12.5%, respectively. Reported incidence of major bleeding events ranged from 0% to 2.9%. Reported overall mortality ranged from 2.5% to 50.5% across studies. Thromboprophylaxis protocols varied across institutions and studies, most commonly involving unfractionated heparin (UFH), warfarin, enoxaparin, acetylsalicylic acid (ASA), or combinations of ASA and warfarin, ASA and low-molecular-weight heparin (LMWH), UFH and LMWH, and UFH and ASA; several studies did not specify a protocol. Due to substantial variability in reported event rates, no clear correlation was identified between prophylaxis protocols and postoperative thrombotic complications. Despite guidance recommending postoperative UFH as standard practice, thromboprophylaxis protocols varied across institutions and studies. More robust trials evaluating different thromboprophylaxis regimens for the management of these patients are warranted.

Hypoplastic left heart syndrome: from comfort care to long-term survival

The management of hypoplastic left heart syndrome (HLHS) has changed substantially over the past four decades. In the 1970s, children with HLHS could only be provided with supportive care. As a result, most of these unfortunate children died within the neonatal period. The advent of the Norwood procedure in the early 1980s has changed the prognosis for these children, and the majority now undergoing a series of three surgical stages that can support survival beyond the neonatal period and into early adulthood. This review will focus on the Norwood procedure and the other important innovations of the last half century that have improved our outlook toward children born with HLHS.

Eponymous cardiovascular surgeries for congenital heart diseases--imaging review and historical perspectives

Advances in pediatric cardiology and cardiac surgical techniques over the past few decades have revolutionized the management of the patients with congenital heart disease, and many now survive into adulthood. Several eponymous surgical procedures performed for congenital heart disease have been named after eminent surgeons. In this article, we provide a short biography of the surgeons associated with these eponymous surgical procedures along with their other important scientific contributions. This is followed by a review of these surgical procedures and their most common complications. Imaging appearances of these surgical procedures along with common complications are described and illustrated, with particular emphasis on magnetic resonance imaging. The surgical procedures described in this review include Blalock-Taussig, Potts, Waterston, Glenn, Fontan, Kawashima, Norwood, Sano, Damus-Kaye-Stansel, Mustard, Senning, Jatene, LeCompte, Rastelli, Rashkind, Ross, and Waldenhausen.

The Hemi-Fontan operation: A critical overview

The hemi-Fontan (HF) operation is a staging procedure in the journey towards an ultimate Fontan palliation. Although popular in the Western world, it has found limited application in the developing world. In this review we discuss the indications, techniques, merits, and demerits of this procedure along with its present day role in developing world where there is lack of awareness about this operation.

Reflections on five decades of the fontan kreutzer procedure

The first successful total right heart bypass via atriopulmonary anastomosis (APA) were reported in 1971 for patients with tricuspid atresia. At the Children's Hospital of Buenos Aires, the cohort of such procedures started in July, when the first fenestrated right heart by pass was performed, with the interposition of a homograft between the right atrial appendage and the main pulmonary artery. In the second patient, instead of placing a homograft, the APA was achieved with the patient's own pulmonary root harvested from the outflow tract of the right ventricle. These techniques were soon replaced in 1978 with the development of the direct valveless posterior APA. Since the very beginning the principle was that the right atrium only functions as a pathway rather than a pump (reason why no inferior vena cava valves were ever used), and the diastolic properties of the systemic ventricle regulate the only real "pump" of this system. The late hemodynamic problems inherent of the APA diminished with modern surgical techniques like the lateral tunnel (LT) or the extracardiac conduit (EC). In spite of the improvement in prognosis and quality of life that the modern techniques have brought for univentricular hearts (UH), with the passing of time, deterioration of this system is frequently seen, due to chronic low cardiac output, elevated central venous pressure making heart transplantation the final stage of treatment. Progressive increase in pulmonary vascular resistances and ventricular dysfunction result in a decline in quality of life and survival. However, the timing of this occurrence is variable, and many survivors enjoy today a satisfactory clinical status. The challenge is to develop a better solution for UH, but in the mean time the Fontan Kreutzer palliation represents the best and only surgical option. It is undoubtedly one of the triumphs of cardiac surgery in congenital heart disease.

The use of reconstructive surgery to improve quality of life and survival in prenatal hypoplastic left heart syndrome

Outcomes for hypoplastic left heart syndrome have improved substantially in the era of prenatal diagnosis. Current stage 1 survival rates are in excess of 90% in the absence of risk factors. However, fetuses with an intact atrial septum continue to have poor postnatal survival. Accurate diagnosis of these fetuses with an intact atrial septum relies upon careful assessment of the patent foramen ovale, pulmonary venous Doppler flow patterns and branch pulmonary artery Doppler flow patterns. Prenatal and perinatal interventions, such as the placement of an atrial stent in utero or delivery at a center where a stent may be placed immediately after birth to relieve left atrial hypertension, may improve survival in this particularly high-risk group.

The intra/extracardiac conduit fenestrated fontan

The intra/extracardiac conduit technique for the Fontan procedure has important advantages relative to the extracardiac conduit. Fenestration is easily achieved and there is less risk of injury to the crista terminalis, so that the risk of late atrial arrhythmias may be reduced.

Intracardiac cavopulmonary connection in patients with univentricular heart using intra-atrial lateral tunnel and intra-atrial conduit techniques

BACKGROUND

In this study, we analyzed the time course of hemodynamic efficiency and follow-up in Fontan candidates who underwent the bidirectional Glenn procedure for staged intracardiac cavopulmonary connection (ICPC).

METHODS

Between 1991 and 2008, 52 patients with univentricular heart (mean age, 3.3 years; range, 2-8 years; 27 female patients [51.9%]) underwent ICPC. The cardiac malformations were as follows: tricuspid atresia, 25 cases (48.0%); common ventricle, 16 cases (30.7%); and pulmonary atresia with intact ventricular septum, 11 cases (21.1%). The intracardiac cavopulmonary procedure was indicated for all 52 cases. In 42 patients (80.7%), an intra-atrial lateral tunnel was constructed with a bovine pericardium patch. In the last 10 consecutive cases (19.3%), we performed a modified surgical technique in which we implanted an intra-atrial corrugated bovine pericardium tube sutured around the superior and inferior vena cava ostium. In all cases, a 4-mm fenestration was made to reduce the intratunnel pressure. All 52 patients had previously undergone a Glenn operation.

RESULTS

There were 2 hospital deaths (3.8%) and no recorded late deaths. During the follow-up, all patients were medicated with antiplatelet drugs. To evaluate the hemodynamic performance, we used Doppler echocardiography, computed tomography, and magnetic nuclear resonance studies. There were no prosthesis thromboses during this followup period. To evaluate cardiac arrhythmias, we conducted a Holter study. The last 10 patients with an intra-atrial conduit (IAC) presented with sinus rhythm and no arrhythmias during the last 4 years. The 50 surviving patients (96.1%) have been followed up for 6 to 204 months; all these patients are free of reoperation.

CONCLUSION

The Glenn operation, which is performed at an early age, prepares the pulmonary bed to receive the ICPC. The midterm results of the intracardiac Fontan procedure seem to be good. The modified surgical procedure (IAC) can be a good alternative technique to the Fontan procedure in suitable patients.

The Fontan/Kreutzer procedure at 40: an operation for the correction of tricuspid atresia

The first atriopulmonary anastomosis (APA) with neither a valve in the inferior vena cava (IVC) nor an Glenn shunt was performed in 1971. A fenestration was intentionally left in the atrial septum. In a second patient, the APA incorporated the patient's own pulmonary valve, which had been removed from the outflow tract of the right ventricle. Since the early days, our rationale was that the right atrium would only function as a pathway, and the end diastolic pressure and the systole of the main ventricle would be the principal "pump" of this system. The late hemodynamic problems of the APA have decreased with newer and better surgical techniques, such as the lateral tunnel (LT) or the extracardiac conduit (EC). Although these procedures have improved the prognosis and quality of life of patients with a univentricular heart (UH), in the long run, deterioration frequently occurs because of chronic low cardiac output and high central venous pressure. Progressive increase in pulmonary vascular resistances and ventricular dysfunction are frequently the underlying reasons for this deterioration. However, such deterioration is not inevitable in every case, as shown in the longest survivor of the world after 34 years of follow-up. The Fontan Kreutzer (FK) palliation represents the best surgical option despite its uncertain late outcome. Certainly, it is one of the triumphs of cardiac surgery in congenital heart disease.

Staged surgical palliation in hypoplastic left heart syndrome and its variants

BACKGROUND

Surgical options for infants with hypoplastic left heart syndrome (HLHS) and/or its variants are cardiac transplantation or the heart-preserving staged palliation with Norwood operation,followed by a two-staged Fontan procedure. We describe our 17-year experience with staged palliation of HLHS and/or its variants.

METHODS

Between December 1989 and December 2006, 64 patients with HLHS and/or its variants underwent a Norwood procedure (mean age/weight, 11.8+/-2.5 days/3.4 kg). Forty-four patients had classical HLHS. Twenty-eight percent had associated congenital cardiac, structural, and genetic anomalies. Subsequently, 25 patients underwent a bidirectional Glenn procedure (stage II) and 11 patients a modified Fontan procedure (stage III). Others await stage II and/or stage III. The follow-up was 143.2 patient-years.

RESULTS

Including the learning curve, overall early mortality from 1989 to 1999 after the Norwood procedure was 39.06%. This decreased tremendously for the last seven years, and reduced to 12.8% in 2000 to 2003 until 0% in 2004 to 2006 (p < 0.005). The causes of mortality were sepsis, capillary leak,or heart failure. Three patients died between stages II and III. One patient underwent heart transplantation after the second stage because of heart failure. Among 34 Norwood survivors, four are slightly tachypneic from a mild pulmonary hyperperfusion; one presents symptoms of minimal brain disease.

CONCLUSION

This report identified an outcome improvement after staged palliation of HLHS, attributed to an increase in experience and expertise gained over time. Lower operative weight, ascending aortic size, prolonged duration of cardiopulmonary bypass, and hypothermic circulatory arrest were identified to significantly influence early mortality after the Norwood procedure.

Single ventricle palliation: Greater risk of complications with the Fontan procedure than with the bidirectional Glenn procedure alone

BACKGROUND

This study was performed to evaluate and compare the early, intermediate, and long-term outcomes of the bidirectional Glenn procedure and Fontan procedure in patients who live at moderately high altitude.

METHODS

The outcome of each method of palliation for patients with a functionally single ventricle was retrospectively evaluated from a review of medical records.

RESULTS

The bidirectional Glenn procedure was performed in 177 patients from October 1984 to June 2004. The Fontan procedure was performed in 149 patients from June 1978 to June 2004. Cardiovascular death or heart transplantation occurred in 8% of patients after the bidirectional Glenn procedure and 17% of patients after the Fontan procedure. Complications of systemic thromboembolic events, bleeding associated with anticoagulation therapy, protein losing enteropathy, and arrhythmias requiring implantation of a pacemaker, cardioversion, or radiofrequency ablation occurred in 7% of patients after the bidirectional Glenn procedure and 47% of patients after the Fontan procedure. Cardiovascular deaths and heart transplantation occurred less frequently when the Fontan procedure was performed in patients with a previous bidirectional Glenn procedure. However, the actuarial transplant-free survival and freedom from complications was not superior for a subgroup of patients who had a Fontan procedure after a bidirectional Glenn procedure in comparison to a subgroup of patients who had a bidirectional Glenn procedure alone.

CONCLUSIONS

The bidirectional Glenn procedure can be used for long-term palliation of patients with a functionally single ventricle. Additional palliation with a Fontan procedure may increase the risk of stroke, protein losing enteropathy and arrhythmias without improving survival.

Single-ventricle physiology: perioperative implications

Neonates with functional single ventricles have pulmonary and systemic circulations that are supplied in parallel, creating significant cyanosis and ventricular volume overload. The goal of palliative surgery, excluding transplantation, is to convert single-ventricle circulation from a parallel to a series arrangement. This will ultimately require a complete cavopulmonary anastomosis (Fontan-type procedure) in which vena caval blood is rerouted directly into the pulmonary circulation. Various factors require that this palliation occur in stages. Stage I surgery, which is often a Norwood procedure, is done in the neonatal period and stabilizes, but does not resolve, parallel circulation. The tenuous balance between pulmonary and systemic perfusion during this stage makes noncardiac surgery hazardous, and it should be restricted to urgent or emergent indications. Stage II surgery, or partial cavopulmonary anastomosis, relieves both parallel circulation and volume overload, but not cyanosis. Relatively stable hemodynamics during this stage create favorable conditions for elective surgery. Patients who have undergone stage III surgery, the Fontan-type repair, vary in age from toddlers to adults, and in physical status from well-compensated to significantly debilitated. Fontan patients require thorough preoperative assessment when elective surgery is contemplated. Optimal communication between surgeons, anesthesiologists, and cardiologists is essential when caring for the patient with single-ventricle physiology.

The Southern Thoracic Surgical Association 50th anniversary celebration: the impact of STSA pediatric cardiothoracic surgery manuscripts on surgical practice

BACKGROUND

Members of the Southern Thoracic Surgical Association (STSA) have presented important pediatric cardiothoracic surgery papers at the annual meetings over the last 50 years. In order to determine the influence of these presentations on the practice of surgery, a review was undertaken. Early papers were characterized by emerging advances in open-heart surgery, anatomic congenital heart studies, and electrophysiologic discoveries that extended life with pacemakers. Later years were characterized by innovative myocardial preservation methods, improved cardiopulmonary bypass techniques, expanded homograft availability, emphasis on accurate repairs, intraoperative transesophageal echocardiography, and cardiopulmonary transplantation.

METHODS

All but one of the scientific programs of the annual meetings (that of 1964) were located. The programs were reviewed and 180 presentations were identified on topics in congenital heart disease, pediatric thoracic disease, and pediatric thoracic wall abnormalities. Of those 180 oral presentations, 155 manuscripts (86%) were eventually published or in press and available for critical review and analysis. Manuscripts were grouped by diagnosis or therapeutic intervention. We determined a "cumulative citation frequency" (CCF), which measures the number of times an article is cited in the bibliography of related papers in the universe of participating journals. The selected manuscripts were compared with the historic landmark contributions and the existing trends at the time, and the number of articles both by individual authors and from institutions were tallied.

RESULTS

Grouping by authors and institutions showed that 100 of 155 pediatric cardiothoracic manuscripts (65%) originated from 13 institutions. The CCF for the 20 leading articles ranged from 26 to 93.

CONCLUSIONS

This historical STSA 50-year record of pediatric cardiothoracic advances was accomplished in a milieu of collegial respect and camaraderie. Our annual meetings over the years have provided a venue for thoracic surgeons to share their ideas, innovations, and scientific inquiry. These contributions have significantly affected the practice of pediatric cardiothoracic surgery. The STSA has worked for 50 years and we trust that it will work for another 50 years and beyond.

Care of children who have had surgery for congenital heart disease

Children who have had surgical correction for congenital heart disease can present to the ED with an acute illness that could be associated with their cardiac lesion. There is no data available to summarize complications that could be associated with surgically corrected congenital heart disease. This work was undertaken to describe the common procedures used, list known complications of these procedures, and review general management principles in caring for the acutely ill child who has had heart surgery.

Evolution of staged approach for Fontan operation

BACKGROUND

During the early development of the Fontan operation, a number of physiologic and anatomical limits were proposed as selection criteria, and two criteria, pulmonary vascular resistance and ventricular function, have been important in predicting surgical outcome. The use of the bidirectional cavo pulmonary shunt as a staging procedure performed to control the pulmonary blood flow adequately and reduce ventricular volume over load has resulted in marked improvements in the early and late Fontan procedure results.

METHODS AND RESULTS

At our hospital we perform systemic pulmonary shunt or pulmonary artery banding in patients if pulmonary blood flow can not be controlled adequately in the neonatal period and then perform bidirectional cavo pulmonary shunt six months afterwards. During this operation we also performed simultaneous surgical repair for pulmonary artery distortion, anomalies of pulmonary venous connection, restriction of bulboventricular foramen and atrioventricular valve regurgitation. To determine the efficacy of this staged approach in avoiding increases in pulmonary vascular resistance and impaired ventricular function, surgical results were investigated. From February 1995 to May 2001, eighteen patients with cardiac morphology unsuitable for biventricular repair were admitted to our hospital. Twenty-six palliative procedures, were performed including seven pulmonary artery banding, three systemic pulmonary shunt, thirteen bidirectional cavo pulmonary shunt, one original Glenn procedure, four repair of coarctation of the aorta, two total anomalous pulmonary venous connection repair, one mitral valve plasty, and two patients required Damus-Kaye-Stansel procedure to release restrictive bulboventricular foramen. Fifteen patients underwent a modified Fontan operation (total cavopulmonary connection) after these palliative procedures. The operative mortality rate for these palliative procedures was 3.8% (1/26). The operative mortality rate for Fontan operation was 7.1% (1/14). Three patients awaiting the Fontan operation were considered good candidates for a final operation and no patients in this series were considered unsuitable for Fontan completion.

CONCLUSION

Our strategy of staged approach for Fontan procedure offers a good prognosis.

Intraoperative evaluation of pulmonary artery flow during the Fontan procedure by transesophageal Doppler echocardiography

After the Fontan procedure, pulmonary artery (PA) flow is maintained without right ventricular pump function. We evaluated intraoperative PA flow velocity patterns using transesophageal Doppler echocardiography (TEE) immediately after cardiopulmonary bypass (CPB) in patients during Fontan or hemi-Fontan procedures. We studied 10 patients with single-ventricle physiology (age range, 5 mo to 3 yr 1 mo). Anesthesia was induced and maintained with fentanyl. After induction of anesthesia, a pediatric TEE probe was inserted into the esophagus. All patients had surgical repair involving direct anastomosis of the right atrium to the PA. Immediately after completion of CPB, adequacy of the atriopulmonary anastomosis was assessed and PA flow velocity was recorded. In all patients, the atriopulmonary anastomosis was clearly defined using a single-plane TEE probe, and PA flow recording was completed successfully. Intraoperative PA flow velocities showed two distinct patterns. Biphasic forward flows with peak velocities during systole and diastole were observed in six patients. The remaining four patients showed forward flows with flow reversals. The four patients demonstrating flow reversals showed significantly reduced fractional shortening (26.5+/-2.1% vs. 35.5+/-6.3%) and larger pressure gradient between the right atrium and left atrium (10.8+/-1.3 mm Hg vs 8.0+/-0.9 mm Hg) when compared to those without reverse flow. Two patients with reverse flow required reoperation because of hypotension. Because PA flow is influenced by pulmonary vascular resistance and left ventricular function, TEE assessed intraoperative PA flow should be further evaluated as a useful predictor of surgical outcome after a Fontan procedure.

Early results of the fontan procedure in one hundred consecutive patients with hypoplastic left heart syndrome

OBJECTIVES

The purpose of this study was to review a large, single institutional experience with the Fontan procedure for patients with hypoplastic left heart syndrome.

METHODS

One hundred consecutive patients with "classic" hypoplastic left heart syndrome underwent Fontan palliation between February 1992 and April 1998. Patient demographic, morphologic, and procedural variables were examined and analyzed. In particular, two different surgical techniques were used: technique I (February 1992 to December 1995) employed cardiopulmonary bypass and moderate systemic hypothermia, and technique II (December 1995 to April 1998), profound hypothermia and circulatory arrest. A retrospective review of medical records was performed and variables were examined and analyzed.

RESULTS

Hospital survival for the entire cohort was 89% (95% CI 83%-95%). The technique of operation, cardiopulmonary bypass time, and aortic crossclamp time were each strongly associated with survival. Survival for patients treated by technique I was 79% (95% CI 68-91%; n = 48) and for those treated by technique II, 98% (95% CI 94%-100%; n = 52). Cardiopulmonary bypass and crossclamp times were also highly correlated with time to extubation and length of intensive care unit stay. Preoperative pulmonary artery pressure was correlated with survival; preoperative oxygen saturation, right atrial pressure, pulmonary vascular resistance, pulmonary artery size, extent of aortopulmonary artery collaterals, and echocardiographic estimates of ventricular function and tricuspid regurgitation were not correlated with survival.

CONCLUSIONS

Our recent experience with Fontan palliation for patients with hypoplastic left heart syndrome suggests that it is attended by low perioperative mortality. The precise operative technique used appears to be an important determinant of outcome, with the duration of cardiopulmonary bypass and crossclamping being particularly significant.

Hemi-Fontan procedure for hypoplastic left heart syndrome: outcome and suitability for Fontan

BACKGROUND

Following the Norwood procedure for hypoplastic left heart syndrome (HLHS), pulmonary artery distortion and hypoplasia are common and may negatively impact late outcome. The hemi-Fontan procedure (HFP) augments the central pulmonary arteries and establishes a connection between the right atrial/superior vena cava junction and the pulmonary arteries, while excluding the inferior vena cava.

METHODS

The hospital records of all 114 patients undergoing a HFP for HLHS between August 1993 and April 1998 were reviewed to assess patient, procedural, and morphologic determinations of outcome. The results of cardiac catheterization, Doppler/echocardiography, 12 lead electrocardiograms, hospital and subsequent course, as well as suitability and outcome for the Fontan procedure were analyzed.

RESULTS

Mean age was 5.4 months (range 1.5 to 15 months). Right ventricular function was normal in 95 patients, moderately depressed in 14, and severely depressed in five. Tricuspid regurgitation was absent or mild in 91 patients, moderate in 13, and severe in 10. Concomitant procedures included left superior vena cava to pulmonary artery anastomosis (12), tricuspid valve repair (10), pulmonary artery stent placement (3), coarctation repair (2), and aortic pseudoaneurysm repair (1). Hospital survival was 112/114, 98% (95% confidence interval [CI]: 95% to 100%). There were two late deaths, one noncardiac. Sinus rhythm is present in 105 patients (92%, 95% CI: 87% to 97%). To date, 79 of these patients have undergone the Fontan procedure with 74 survivors (94%, 95% CI: 89% to 99%).

CONCLUSIONS

The HFP may be performed with excellent results for HLHS. It effectively augments the central pulmonary arteries while preserving sinus rhythm in the majority. In addition, the HFP facilitates the subsequent Fontan procedure and has significantly improved the overall outcome.

The role of a staged approach for high-risk Fontan candidates

The preoperative risk characteristics and surgical outcome were reviewed in 24 patients who underwent a one-stage Fontan procedure (One-stage Group) and in 16 patients who underwent bidirectional cavopulmonary shunt as an interim procedure prior to a subsequent Fontan procedure (Two-stage Group) to clarify the role of the staged approach for high-risk Fontan candidates. There were 2 hospital deaths after the one-stage Fontan, and another 2 after the takedown of the fenestrated Fontan to BCPS in patients considered to be less than ideal candidate because of the presence of 3 or more risk factors. In contrast, among the total of 16 patients in the Two-stage Group who had significantly more risk factors than those in One-stage Group (2.8 +/- 1.4, vs 1.1 +/- 1.2 p < 0.001), 14 patients survived after bidirectional cavopulmonary shunt, and a subsequent Fontan procedure was accomplished in 12 patients of these 14, with 2 operative deaths after the takedown to bidirectional cavopulmonary shunt. The rate of final Fontan completion in the Two-stage Group (10/16, 62.5%) was considered to be reasonable, considering the fact that this patient group essentially includes non-Fontan candidates. Additionally, in the category of high-risk with 3 or more risk factors, the rate of successful Fontan completion was higher in the Two-stage Group than in the One-stage Group (50% vs 25%). In the survivors of the Two-stage Group, the average number of risk factor decreased from 2.7 +/- 1.3 (range 0 to 5) to 1.0 +/- 1.0 (range 0 to 4) after bidirectional cavopulmonary shunt with concomitant procedures (i.e., extended pulmonary artery reconstruction in 8, and repair of atrioventricular valve regurgitation in 4), predominantly due to improved Fontan candidacy, relating to pulmonary and/or ventricular characteristics, and eliminated anatomical risks. In conclusion, the two-stage approach with bidirectional cavopulmonary shunt accompanied by concomitant repair of associated anomaly may be useful to lower the risk enough to allow subsequent Fontan completion in high-risk patients.

Recent advances in the surgical management of the single ventricle pediatric patient

A standardized approach to the patient with single ventricle anatomy (SVA) is presented in this article. Regardless of the specific anatomic subtype, patients with SVA share common risk factors for early and late mortality and morbidity. Management of the SVA patients requires a plan to avoid development of these risk factors. Neonatal palliation is directed at relieving any systemic obstruction and appropriate limitation of pulmonary blood flow. The application of a standardized approach to the neonate with SVA, followed by staged palliation to a completion Fontan procedure should result in improved early and late outcome.

Theoretical optimization of pulmonary-to-systemic flow ratio after a bidirectional cavopulmonary anastomosis

A univentricle with parallel pulmonary and systemic circulations is inherently inefficient because mixing of pulmonary and systemic venous return occurs. Thus a cavopulmonary anastomosis is used as a staged palliative procedure to reduce volume overload in patients with cyanotic congenital heart disease. On the basis of oxygen uptake and consumption, an equation was derived that related cardiac output, pulmonary venous oxygen saturation, upper body oxygen consumption, and superior-to-inferior vena caval blood flow ratio (QSVC/QIVC) to oxygen delivery. The primary findings were as follows. 1) As QSVC/QIVC increases, total body oxygen delivery and arterial and superior vena caval oxygen saturations increase. 2) As QSVC/QIVC increases, lower body oxygen delivery and inferior vena caval oxygen saturation initially increase, then peak, and then decrease. 3) As the percentage of lower body oxygen consumption increases, oxygen delivery and saturation decrease. 4) A cavopulmonary anastomosis decreases the required cardiac output for a given oxygen delivery. Thus we concluded that a high systemic arterial oxygen saturation after cavopulmonary anastomosis requires a high percentage of upper body oxygen consumption and a high QSVC/QIVC and that the cavopulmonary anastomosis reduces the volume load on the single ventricle.

Modified ultrafiltration reduces postoperative morbidity after cavopulmonary connection

BACKGROUND

Modified ultrafiltration reduces the deleterious effects of cardiopulmonary bypass in children. Patients undergoing repair of single-ventricle cardiac anomalies may be particularly sensitive to these adverse effects, and benefit from the use of modified ultrafiltration.

METHODS

From January 1995 to June 1996, 120 consecutive cavopulmonary operations were performed at The Children's Hospital of Philadelphia. Procedures included lateral tunnel fenestrated Fontan (n = 50), extracardiac Fontan (n = 5), hemi-Fontan (n = 60), and bidirectional Glenn shunt (n = 5). Modified ultrafiltration was performed after cardiopulmonary bypass in 41 patients, and results were compared by t test with a control group of 79 patients in whom modified ultrafiltration was not used.

RESULTS

There was one death for an operative (30-day) mortality of 0.8%. Age, weight, diagnosis, ischemic arrest time, and cardiopulmonary bypass time were similar between the modified ultrafiltration and control groups. Postoperative blood use, chest tube output, the incidence of pleural and pericardial effusions, and hospital stay were all significantly decreased when modified ultrafiltration was used.

CONCLUSIONS

By lowering the perioperative morbidity of staged cavopulmonary operations, modified ultrafiltration makes an important contribution to improving outcome after the correction of single-ventricle cardiac anomalies.

Bidirectional inferior vena cava-pulmonary artery shunt

BACKGROUND

Bidirectional superior vena cava-pulmonary shunt is widely used as an interim palliation for patients with univentricular hearts. Bidirectional inferior vena cava-pulmonary artery shunt, as an alternative approach of partial Fontan circulation, may offer the advantage of performing the complete Fontan circulation more easily due to the already constructed inferior vena cava lateral tunnel.

METHODS

We used bidirectional inferior vena cava-pulmonary artery shunt in 2 patients. Contraindications to a complete Fontan circulation were due to, respectively, a volume-overloaded systemic ventricle and an irregular pulmonary arterial tree.

RESULTS

Postoperative courses were uneventful. There were no significant pleural effusions. Transcutaneous oxygen saturations were 77% and 78%. Pulmonary-to-systemic blood flow ratios were 0.57 and 0.63. A complete Fontan circulation was safely performed 8 and 12 months later, without any "Fontan-related" complications.

CONCLUSIONS

Bidirectional inferior vena cava-pulmonary artery shunt can be useful in selected patients with univentricular hearts, although its place in the field of "partial Fontan operations" cannot be determined as yet.

Surgical management of hypoplastic left heart syndrome

BACKGROUND

The treatment of infants with hypoplastic left heart syndrome has been challenging and controversial.

METHODS

To assess the operative management and intermediate-term outcome, we retrospectively analyzed our surgical experience with 50 newborns with hypoplastic left heart syndrome operated on between January 1989 and June 1995.

RESULTS

Surgical palliation with a first-stage Norwood operation was offered to 28 patients. The remaining 22 infants were initially listed for heart transplantation, and 15 underwent the operation. Ten of the 15 recipients are alive, and all are in New York Heart Association class I. Seven infants underwent a Norwood procedure after being on the list for transplantation for 12 to 42 days. A total of 34 patients underwent Norwood procedures with one operation aborted because of inoperable anatomy. Two infants who survived the first-stage Norwood operation underwent subsequent heart transplantation and are currently doing well. The 1-year mortality rate for heart transplantation was 18% (3/17) versus 50% (17/34) for the Norwood procedure. Risk factors for early mortality after a Norwood procedure include longer circulatory arrest time (> 50 minutes), preoperative acidosis (pH < 7.20), larger systemic-pulmonary artery shunt (> or = 4 mm), diminutive ascending aorta (< or = 2.0 mm), and anatomic subtype of aortic and mitral atresia. The 1-year survival rate for the Norwood procedure improved from 36% for the patients operated on during 1989 through 1992 to 75% during 1993 to mid-1995 (p = 0.005). Of the 17 survivors of a first-stage Norwood operation, 10 have undergone the second stage (bidirectional Glenn procedure), and 7 have completed a Fontan procedure. Heart transplantation results have also improved, with no deaths since 1992.

CONCLUSIONS

Both the Norwood procedure and heart transplantation have encouraging early to intermediate results in infants with hypoplastic left heart syndrome. Hypoplastic left heart syndrome should be managed selectively on the basis of cardiac morphology, donor availability, and family wishes. Development of a flexible program involving the use of both procedures may aid in the successful management of infants with hypoplastic left heart syndrome.

Aortopulmonary collateral vessels and prolonged pleural effusions after modified Fontan procedures

Pleural effusions after the modified Fontan procedure are unpredictable, increase morbidity, and prolong hospital stay. To assess the relation between preoperative characteristics and postoperative pleural drainage, we performed a retrospective study of 71 patients who underwent Fontan procedures. Analyses revealed no significant relation between duration of effusion and age at Fontan, preoperative oxygen saturation, pulmonary artery pressure, ventricular end-diastolic pressure, type of Fontan, or prior cavopulmonary anastomosis. Patients with significant aortopulmonary collateral vessels evidenced by angiographic opacification of the pulmonary arteries or veins had more prolonged pleural drainage. The duration of the pleural drainage was significantly less in patients who had aortopulmonary collateral occlusion.

Staged operation to Fontan increases the incidence of sinoatrial node dysfunction

Morbidity and mortality of total cavopulmonary connection (modified Fontan procedure) may be decreased in many patients with single ventricle in whom the risk of surgery is high by performing the operations in a staged fashion. Each operative intervention, however, exposes the sinoatrial node region to risk of injury, and a multistaged approach may increase the risk of altered sinoatrial node function in these patients. The purpose of this study was to compare the prevalence of perioperative arrhythmias in patients undergoing either a primary or staged approach to the Fontan operation. Records were retrospectively reviewed for all patients having a Fontan procedure between January 1988 and December 1992. Of 324 patients undergoing a Fontan operation, 227 had a Fontan operation without a prior cavopulmonary shunt (group 1) and 97 had a cavopulmonary shunt before a Fontan operation (group 2). Arrhythmias were classified as altered sinoatrial node function, supraventricular tachycardia, or atrioventricular block. The prevalence of both transient (resolving before hospital discharge) and fixed (persisting until hospital discharge) altered sinoatrial node function was similar for the two groups after cavopulmonary shunt or primary Fontan despite a heterogeneous patient population (group 1: 10.6%/4.4%; group 2: 10.3%/3.1%; p=0.28). Conversion from cavopulmonary shunt to Fontan in group 2 resulted in a higher prevalence of altered sinoatrial node function in the early postoperative period (transient: 23.7%; fixed: 23.7%; p < 0.001) and on follow-up (group 1: 7.7%; group 2: 16.7%; p < 0.02). In group 2, 40 of 82 patients without arrhythmia after first intervention (cavopulmonary shunt) had an arrhythmia after the second intervention (Fontan) (49%); of 14 with an arrhythmia after the first operation, 10 (71%) had one at the second intervention (p < 0.01). In conclusion, a multistaged operative pathway to Fontan reconstruction is associated with a higher early risk of altered sinoatrial node function. The occurrence of altered sinoatrial node function after cavopulmonary shunt is itself a risk factor for arrhythmia after the Fontan operation. Longer follow-up is needed to assess the full impact of this finding.

Factors influencing perioperative morbidity during palliation of the univentricular heart

BACKGROUND

The modified Fontan procedure has become the treatment of choice for patients born with a univentricular heart. Although the operative mortality has steadily decreased in recent years, the hospital stay is still prolonged in many patients due to fluid retention and pleural effusions.

METHODS

We retrospectively analyzed subsets of patients undergoing the bidirectional cavopulmonary shunt (BDCPS) and modified Fontan procedure in an attempt to define factors influencing operative mortality and morbidity.

RESULTS

Multivariate analysis of 64 patients undergoing BDCPS revealed that age 6 months or less, concomitant operation, mean pulmonary pressure of 15 mm Hg or less, and mean pulmonary artery ratio of 1.8:1 or less were not statistically significant indicators of risk. Abnormal pulmonary artery architecture was a significant predictor of early and late death (p < or = 0.01). Retrospective analysis of 71 patients undergoing the modified Fontan procedure revealed no significant relationship between duration of pleural effusions and age at operation, preoperative oxygen saturation, pulmonary artery pressure, ventricular end-diastolic pressure, or prior BDCPS: Patients with important aortopulmonary collateral vessels defined by angiography had prolonged pleural drainage. Selective use of the total extracardiac conduit and the fenestrated Fontan resulted in low overall mortality with no statistical differences between subsets of patients undergoing different modifications of the Fontan procedure.

CONCLUSIONS

These data indicate that the operative risk for BDCPS or modified Fontan procedure is quite low if a procedure appropriate for the patient is selected. Abnormal pulmonary artery architecture is an important risk factor for death after the BDCPS: Aortopulmonary collateral vessels are associated with fluid retention and pleural effusions after a modified Fontan procedure. Important aortopulmonary collateral vessels should be occluded before or during the modified Fontan procedure.

Modified hemi-Fontan operation: an alternative definitive palliation for high-risk patients

BACKGROUND

We conceptualized that by adding small amounts of prograde pulmonary blood flow to the hemi-Fontan operation, or bidirectional Glenn procedure, this modified hemi-Fontan operation could be safely done at an early age, with better oxygenation, and with less potential for pulmonary arteriovenous fistulae.

METHODS

Since April 1992 the hemi-Fontan operation was modified by adding some prograde flow through the native pulmonary artery in 10 high-risk infants, either by leaving the critical subpulmonary stenosis untreated (n = 6) or by tightening a previously placed pulmonary artery band (n = 4). All other sources of pulmonary blood flow were interrupted. Patients were 4 to 23 months old (3.8 to 10.3 kg). Diagnoses included isolated dextrocardia with single ventricle (3) and polysplenia syndrome (2). Cardiopulmonary bypass was needed in 5 patients.

RESULTS

There were no hospital deaths. Mean postoperative intensive care unit stay was 2 days, and 9 of 10 patients were discharged within 7 days of operation. One 4-month-old infant with Down's syndrome survived postoperative takedown of the hemi-Fontan repair after pneumonia and caval thrombosis developed. Eight patients are currently asymptomatic receiving minimal modification, and oxygen saturations range from 84% to 93%.

CONCLUSIONS

Adding small volumes of prograde pulmonary blood flow to the hemi-Fontan operation is safe, provides improved oxygenation, may encourage growth of central pulmonary arteries, and represent an alternative definitive palliation for high-risk Fontan candidates.

Conversion of the hemi-Fontan procedure to fenestrated total extracardiac cavopulmonary bypass

BACKGROUND

Arrhythmias occur frequently after Fontan operations, and are related in part to high atrial pressure, wall distention, and scarring caused by extensive suture lines. These arrhythmic factors may be avoided by an extracardiac total cavopulmonary anastomosis. We have embarked on a program of conversion of the hemi-Fontan operation to a fenestrated extracardiac Fontan procedure with a relatively simple operation.

METHODS

In a 4-month period ending in December 1994, 4 consecutive patients underwent this procedure. The inferior vena cava was divided and the cardiac end was oversewn. A large (20 to 25 mm) ascending aortic homograft, from which the inlet portion and valve had previously been excised, was interposed between the divided distal end of the inferior vena cava and the hood of the superior cavopulmonary anastomosis. A 4-mm fenestration with a pursestring snare mechanism was placed within the cavoatrial patch that had been implanted at the time of the hemi-Fontan procedure.

RESULTS

There were no deaths, and the average length of stay was 12 +/- 4 days (range, 8 to 18 days). In early follow-up, there have been no atrial arrhythmias, and three of the four fenestrations have been documented to be patent.

CONCLUSIONS

An extracardiac fenestrated Fontan procedure can safely and successfully be performed after a hemi-Fontan operation, and may have both hemodynamic and arrhythmic benefits.

Bidirectional Glenn. Is accessory pulmonary blood flow good or bad?

BACKGROUND

The bidirectional Glenn (BDG) is frequently used in the staged surgical management of single ventricle patients. Controversy exists whether accessory pulmonary blood flow (APBF) sources should be left at the time of the BDG to augment systemic saturation or should be eliminated to reduce volume load of the ventricle. The present study was a retrospective review to assess the influence of APBF on outcome after the BDG.

METHODS AND RESULTS

Ninety-two patients have undergone BDG at our institute during the interval from 1986 through 1994. At the time of BDG, 40 patients had either a systemic-to-pulmonary artery shunt or patent right ventricular outflow tract as an additional source of pulmonary blood flow. Fifty-two patients had elimination of APBF. There were three operative deaths (two with and one without APBF) and four procedures (two in each group) that failed and required subsequent revision. Thus, there were 85 patients who underwent successful operation. Effusions (defined as chest tube drainage exceeding 7 days' duration) occurred in 8 of 85 patients; this complication was seen in 7 of 36 patients (19%) with APBF and 1 of 49 patients (2%) without APBF (P < .05). There were 11 deaths, including 6 patients (17%) with APBF, 2 patients (4%) without APBF, and 3 of the patients (75%) who had a failed BDG.

CONCLUSIONS

The data suggest that morbidity and mortality are lower in patients in whom APBF is eliminated at the time of the BDG.

Use of the bidirectional Glenn procedure in the presence of forward flow from the ventricles to the pulmonary arteries

BACKGROUND

Relative regression of the pulmonary arterial size has been reported after a conventional bidirectional Glenn procedure. Maintaining a supplemental pulmonary flow could be of surgical value unless the option also militates against the efficacy of the partial right heart bypass.

METHODS AND RESULTS

Twenty-seven patients considered unsuitable for a Fontan-type procedure underwent a bidirectional Glenn procedure in the presence of forward flow from the ventricles to the pulmonary arteries, the flow being maintained through the pulmonary trunk in 22 or a systemic-to-pulmonary shunt in 5. There was one surgical death due to atrioventricular valvular regurgitation. Subsequently, 9 patients have successfully undergone a total cavopulmonary connection 2.6 +/- 1.9 years after the initial procedure. Preoperative and postoperative catheterizations revealed changes in arterial oxygen saturation (75 +/- 11% compared with 83 +/- 7%, P < .001) and end-diastolic volumes of the systemic ventricles (from 238 +/- 92% to 188 +/- 97% of the expected normal volume, P < .01), whereas no difference was detected in the mean cross-sectional area of the right and left pulmonary arteries compared with the expected normal value for the right pulmonary artery (from 76 +/- 21% to 81 +/- 20%) or in the ventricular ejection fraction (from 53 +/- 8% to 50 +/- 14%). The relative regression or growth of the pulmonary arterial size was statistically related to the size of the channel for forward flow.

CONCLUSIONS

Maintenance of forward flow from the ventricle provides a feasible means, when performing a bidirectional Glenn procedure, of protecting against regression of pulmonary arterial size as well as off-loading the ventricles and improving arterial oxygen saturation.

Influence of competitive pulmonary blood flow on the bidirectional superior cavopulmonary shunt. A multi-institutional study

BACKGROUND

It is common practice to interrupt all alternative sources of pulmonary blood flow ("competitive flow") at the time of a bidirectional superior cavopulmonary anastomosis (BCPA), although the merits of this have not been systematically studied.

METHODS AND RESULTS

We reviewed the early and medium-term clinical and hemodynamic findings in 108 consecutive patients 3 weeks to 25 years old (median, 1.9 years) undergoing BCPA at one of three institutions. Preoperatively, pulmonary blood flow was dependent on antegrade ventricular flow (n = 50), systemic-to-pulmonary shunts (n = 33), or mixed sources (n = 25). Postoperatively, competitive sources of pulmonary blood flow were left patent in 43 of 108 patients (40%). There were four early (3.7%) and four late deaths, none related to persistence of competitive flow. After BCPA, patients with competitive flow had significantly higher systemic oxygen saturations at 1 hour (85% versus 79%), 24 hours (84% versus 78%), and at hospital discharge (84% versus 78%) and required a shorter period of artificial ventilation (median, 9 versus 24 hours) and intensive care (median, 2 versus 4 days). Oxygen saturations at late follow-up (median, 2.8 years; range, 1 to 7) did not differ (83% versus 82%). No patient developed pulmonary arteriovenous malformations.

CONCLUSIONS

Competitive flow is well tolerated in the short and medium term after BCPA, and early postoperative systemic oxygen saturations are improved. The long-term influence of competitive flow on pulmonary arterial growth, arteriovenous malformation development, and ventricular function warrants investigation.

The modified Fontan operation. An analysis of risk factors for early postoperative death or takedown in 702 consecutive patients from one institution

To better understand risk factors associated with early postoperative death or failure, we reviewed our entire experience with 702 consecutive patients who had the modified Fontan operation at the Mayo Clinic between October 1973 and December 1989. The event rate for takedown of repair or death during the initial hospitalization or within 30 days of the operation was 14.8% (successful takedown of the repair, n = 6; death, n = 98). To identify variables associated with early death or Fontan takedown, we analyzed 33 clinical and hemodynamic variables in a univariate and multivariate manner. On the basis of a stepwise logistic discriminant analysis, patients who were younger and operated on before 1980 with a higher preoperative pulmonary artery mean pressure, asplenia, higher intraoperative (after Fontan operation) right atrial pressure, longer aortic crossclamp time, and pulmonary artery ligation were more likely to have the outcome event of interest (p values < 0.05). A new variable, corrected pulmonary artery pressure (that is, mean preoperative pulmonary artery pressure divided by the ratio of pulmonary to systemic flow if the ratio of pulmonary to systemic flow is greater than 1.0), was significantly associated with the outcome event univariately (p = 0.002), but was no more predictive than the preoperative pulmonary artery mean pressure. Variables less predictive of the outcome event in this analysis included multiple prior operations, polysplenia syndrome, complex anatomy other than asplenia syndrome, and systemic atrioventricular valve regurgitation. These results represent the largest single-institution review of the Fontan operation and suggest that some anatomic and hemodynamic variables previously predictive of poor early outcome have been nullified by current operative methods.

The Norwood operation and subsequent Fontan operation in infants with complex congenital heart disease

From April 1987 to September 1993, 60 infants underwent a Norwood operation for complex congenital heart disease including hypoplastic left heart syndrome (n = 41), ventricular septal defect and subaortic stenosis with aortic arch interruption/severe coarctation (n = 7), complex single right ventricle with subaortic stenosis (n = 8), critical aortic stenosis with endocardial fibroelastosis (n = 2), and malaligned primum atrial septal defect with coarctation (n = 2). Age at operation ranged from 1 day to 3.9 months (mean 9 days, median 3.5 days). The operative mortality (< 30 days) was 33% (20 patients). Late mortality was 17% (10 patients). Nine of the 20 (45%) operative deaths occurred during the first 2 days after the operation as a result of sudden hemodynamic instability. All four infants with premature closure of the foramen ovale had pulmonary lymphangiectasia and died of pulmonary failure. Seven operative deaths have occurred in 36 patients since 1990 (19%); in the past 2 years, no operative deaths have occurred in 22 patients. Overall, there are 30 long-term survivors (50%). Twenty-one of these 30 infants have undergone a two-stage repair with a modified Fontan operation at 7.3 to 27.6 months of age (mean 18.1 months) with no mortality. Six patients have entered a three-stage repair strategy by undergoing a hemi-Fontan procedure at 6.8 to 23.0 months (mean 8.8 months) with no mortality, and two of these patients have now had their modified Fontan operation at 23.0 to 46.7 months of age with no mortality (four are still awaiting surgery). Two patients have undergone a two-ventricle repair with a Rastelli procedure, with no mortality at 7.4 and 14.1 months of age. Early in our experience, infants undergoing the Norwood operation had a high early mortality most often related to sudden hemodynamic instability. After we instituted a protocol that adds carbon dioxide to the inspired gas during postoperative mechanical ventilation, the postoperative course became more stable and there have been no operative deaths. In summary, the operative mortality for the Norwood operation continues to improve. A subsequent Fontan operation can be performed with excellent clinical results.

Comparison of the hormonal response after bidirectional Glenn and Fontan procedures

Fluid retention is a frequent complication after the bidirectional Glenn and Fontan procedures. It was our hypothesis that this fluid retention may have a hormonal basis. To test this hypothesis, we made serial determinations of antidiuretic hormone, cortisol, aldosterone, angiotensin, and renin before and after operation in patients undergoing a bidirectional Glenn (n = 15) or Fontan (n = 18) procedure. Patients undergoing a bidirectional Glenn procedure had elevations in antidiuretic hormone, cortisol, and aldosterone immediately after operation. However, none of the hormonal elevations persisted by the fifth postoperative day. In contrast, patients undergoing a Fontan procedure had elevations in antidiuretic hormone, cortisol, aldosterone, renin, and angiotensin II in the immediate postoperative period. Five days postoperatively, the renin and angiotensin II levels remained elevated compared with the preoperative values. The data demonstrate that patients undergoing a bidirectional Glenn procedure and those undergoing a Fontan procedure have different patterns of hormonal response. These results suggest that hormonal factors may contribute to fluid retention after these operations.

Mid-term results after bidirectional cavopulmonary shunts

Despite the increasing use of the bidirectional cavopulmonary shunt, little is known about the late results, the duration of palliation, and the frequency with which this procedure allows later successful conversion to a Fontan type of procedure. We reviewed our experience (1984 to 1992) in 38 consecutive children, ages 4 months to 16 years (mean, 4.0 years), who underwent a bidirectional cavopulmonary shunt procedure. All had a single functional ventricle and represented high risks for the performance of a Fontan procedure based on anatomic and hemodynamic criteria. The oxygen saturation in these patients improved from a preoperative value of 75% +/- 7% to 82% +/- 7% (p < 0.05) at late cardiac catheterization by a mean of 24 months after operation. The actuarial survival, including early deaths and that associated with all secondary procedures, was 86% at 1 year and 81% at 6 years. Early deaths occurred in 5.3% (2/38) and late deaths in 11% (4/36). Late follow-up ranged from 5 to 90 months (mean, 37 months). Conversion to a Fontan or fenestrated Fontan procedure was accomplished in 21 early survivors (21/36; 58%) by a mean of 26 months after the bidirectional cavopulmonary shunt procedure, with one operative and no late deaths (1/21; 4.8%). Three additional patients have undergone late reoperation, including 2 requiring cardiac transplantation and 1 undergoing the late creation of an axillary artery-to-vein fistula for the treatment of cyanosis. The midterm survival after a bidirectional cavopulmonary shunt procedure appears to be excellent, and it serves as a good staging procedure for patients who represent high risks for a Fontan procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of the bidirectional Glenn procedure as staged reconstruction for the functional single ventricle

The bidirectional Glenn operation may be particularly useful as an intermediate procedure before Fontan correction in high-risk patients. From October 1989 through February 1992, 50 patients 1 to 60 months old (median 12) have undergone a bidirectional Glenn operation. Diagnoses included hypoplastic left heart syndrome in 21 patients, pulmonary atresia with intact ventricular septum in 10, tricuspid valve atresia in 9, other complex univentricular heart defects in 9, and Ebstein's anomaly in 1. Mean pulmonary vascular resistance was 2.2 +/- 0.2 Wood U (range 0.5 to 7.3) and mean pulmonary artery area Nakata index was 318 +/- mm2/m2 (range 80 to 821). Additional procedures were performed in 17 patients, including pulmonary artery reconstruction in 15 (29%) and bilateral caval anastomoses in 5 (10%). There were 4 hospital deaths (8%). Two deaths resulted from myocardial infarction in patients with pulmonary atresia with intact ventricular septum and sinusoids and 1 from severe pulmonary vascular disease in a patient with hypoplastic left heart syndrome. There was 1 late death from pneumonia. Actuarial survival is 92 +/- 4% at 1 month and beyond, with a mean follow-up of 13.4 +/- 1 months. Risk factor analysis showed that pulmonary vascular resistance > 3 Wood U and pulmonary artery distortion were associated with increased mortality. Twelve patients have undergone a Fontan procedure at a mean duration after bidirectional Glenn of 18 months with 1 death (8%). The bidirectional Glenn procedure provides excellent palliation in high-risk patients and appears useful as a staging procedure before Fontan correction.

Effect of baffle fenestration on outcome of the modified Fontan operation

BACKGROUND

The "fenestrated Fontan" (surgical baffle fenestration followed by transcatheter test occlusion and permanent closure after postoperative recovery) was adopted in an effort to reduce perioperative mortality and morbidity. This study assesses the effect of baffle fenestration on outcome.

METHODS AND RESULTS

Patients having a modified Fontan operation with a cavocaval baffle and cavopulmonary anastomosis were retrospectively selected for study. Those with baffle fenestration (n = 91) were compared with those without baffle fenestration (n = 56) with respect to preoperative risk factors, age, anatomy, surgical date, and presence or absence of a previous bidirectional cavopulmonary anastomosis. Outcome variables were failure (death or take-down) and duration of postoperative pleural effusions and hospitalization. Survival and clinical status after hospital discharge were ascertained. The two groups did not appear to differ with respect to age or anatomic diagnosis. Patients having baffle fenestration were at significantly greater preoperative risk by univariate and multivariate analysis (p < 0.01). Operative failure was low in both groups (11% without and 7% with baffle fenestration, p = NS). Durations of pleural effusions and hospitalization were significantly shorter with baffle fenestration (p < 0.01). Neither date of surgery nor a previous bidirectional cavopulmonary anastomosis appeared to contribute to improved outcome. Patients with baffle fenestration had lower postoperative systemic venous pressure (p < 0.01). There were no late deaths. Functional status in both groups is good (82% in New York Heart Association class I).

CONCLUSIONS

Baffle fenestration is associated with low mortality, significantly less pleural effusion, and significantly shorter hospitalization among high-risk patients having a modified Fontan operation.

Transesophageal echocardiography detects thrombus formation not identified by transthoracic echocardiography after the Fontan operation

Transesophageal echocardiography demonstrated six instances of venous thrombus formation in the inferior vena cava, right atrium and caval-pulmonary anastomosis region in four children after a modified Fontan operation. Transthoracic surface echocardiography failed to identify these thrombi in five of the six cases because of the posterior location of the thrombus or imaging interference from surgical hardware. These thrombotic episodes occurred 2 days to 5 years after the Fontan operation in children 25 to 168 months of age. Clinical features of compromised cardiac performance with cyanosis or inadequate perfusion were present during four of the six episodes. In two patients, thrombi occurred around transvenous permanent atrial pacing leads. Therapy to eliminate thrombus included surgery (two cases), anticoagulation with warfarin (three cases) and streptokinase thrombolysis (one case). Disappearance of the thrombus was confirmed by transesophageal study in three of the four cases with follow-up echocardiography. Transesophageal echocardiographic demonstration of atrial and pulmonary thrombi that could not be seen by transthoracic imaging suggests that these thrombi occur with greater frequency in patients who have undergone the Fontan operation than was previously suspected.