Thomas L. Gentles

Fontan operation in five hundred consecutive patients: Factors influencing early and late outcome ☆ ☆☆ ★ ★★ ♢ ♢♢ ♦

OBJECTIVES The purpose of this study was to review a large, evolving, single-center experience with the Fontan operation and to determine risk factors influencing early and late outcome. METHODS The first 500 patients undergoing modifications of the Fontan operation at our institution were identified. Perioperative variables were recorded and a cross-sectional review of survivors was undertaken. RESULTS The incidence of early failure decreased from 27.1% in the first quartile of the experience to 7.5% in the last quartile. In a multivariate model, the following variables were associated with an increased probability of early failure: a mean preoperative pulmonary artery pressure of 19 mm Hg or more (p < 0.001), younger age at operation (p = 0.001), heterotaxy syndrome (p = 0.03), a right-sided tricuspid valve as the only systemic atrioventricular valve (p = 0.001), pulmonary artery distortion (p = 0.04), an atriopulmonary connection originating at the right atrial body or appendage (p = 0.001), the absence of a baffle fenestration (p = 0.002), and longer cardiopulmonary bypass time (p = 0.001). An increased probability of late failure was associated with the presence of a pacemaker before the Fontan operation (p < 0.001). A morphologically left ventricle with normally related great arteries or a single right ventricle (excluding heterotaxy syndrome and hypoplastic left heart syndrome) were associated with a decreased probability of late failure (p = 0.003). CONCLUSIONS These analyses indicate that early failure has declined over the study period and that this decline is related in part to procedural modifications. A continuing late hazard phase is associated with few patient-related variables and does not appear related to procedural variables.

Factors that influence the development of atrial flutter after the fontan operation

OBJECTIVES Atrial flutter is a frequent, potentially fatal complication of the Fontan operation, but risk factors for its development are ill defined. We evaluated clinical features that might predict the development of atrial flutter in patients who had a Fontan operation. METHODS We evaluated 334 early survivors of a Fontan operation done between April 1973 and July 1991 (mean follow-up, 5.0 +/- 3.8 years). Evaluation included electrocardiography, Holter monitor recordings, and chart review. Modifications of the Fontan operation included an extracardiac conduit (n = 43), an atriopulmonary anastomosis (n = 117), or a total cavopulmonary anastomosis (n = 174). Patient, time, and procedure-related variables were analyzed with respect to the development of atrial flutter. RESULTS Atrial flutter was identified in 54 (16%) patients at a mean of 5.3 +/- 4.7 years (range 0 to 19.7 years) after Fontan operation. Atrial flutter developed sooner and was more likely to occur in patients who were older at the time of Fontan operation (12.4 +/- 7.6 vs 6.3 +/- 5.2 years; p < 0.001), had a longer follow-up interval (8.7 +/- 3.9 vs 4.4 +/- 3.4 years; p < 0.001), had a prior atrial septectomy or pulmonary artery reconstruction (p < 0.01), and had worse New York Heart Association class symptoms (p < 0.02). The presence of sinus node dysfunction was associated with a higher incidence of atrial flutter (p < 0.001). Although there was a lower prevalence of atrial flutter in those patients with a total cavopulmonary anastomosis, the follow-up for this group was shorter. Anatomic diagnoses, perioperative hemodynamics, and other previous palliative operations were not associated with an increased incidence of atrial flutter. Multivariate analysis identified age at operation, duration of follow-up, extensive atrial baffling, and type of repair as factors associated with the development of atrial flutter after Fontan operation. CONCLUSION Atrial flutter continues to develop with time after the Fontan operation. Further follow-up is necessary to determine whether a total cavopulmonary anastomosis reduces the incidence of atrial flutter.

Functional outcome after the Fontan operation: Factors influencing late morbidity

OBJECTIVES The purpose of this study was to describe the functional outcome of a large number of patients after modifications of the Fontan operation and to investigate perioperative risk factors that might influence late functional state. METHODS A comprehensive cross-sectional review of the first 500 patients undergoing a Fontan operation at our institution was undertaken. Those surviving with an intact Fontan circulation were reviewed by questionnaire to assess functional status and medication history. Medical records, chest roentgenograms, echocardiograms, cardiac catheterizations, and laboratory investigations were also reviewed to assess postoperative status. RESULTS Three hundred sixty-three long-term survivors with an intact Fontan circulation were identified during cross-sectional follow-up. Median age at operation was 5.0 years (range 0.4 to 31 years), and median follow-up was 5.4 years (range 1.7 to 20 years). Most patients (91.1%) were in New York Heart Association class I or II. In a multivariate model, poor (class III or IV) functional state was associated with longer duration of follow-up (p < 0.001), a prior atrial septectomy (p = 0.03), and a prior main pulmonary artery-ascending aorta anastomosis (p = 0.05). CONCLUSIONS A poor functional outcome is uncommon after the Fontan operation but becomes more frequent with increasing duration of follow-up.

Redefining Expectations of Long-Term Survival After the Fontan Procedure Twenty-Five Years of Follow-Up From the Entire Population of Australia and New Zealand

Background— The life expectancy of patients undergoing a Fontan procedure is unknown. Methods and Results— Follow-up of all 1006 survivors of the 1089 patients who underwent a Fontan procedure in Australia and New Zealand was obtained from a binational population-based registry including all pediatric and adult cardiac centers. There were 203 atriopulmonary connections (AP; 1975–1995), 271 lateral tunnels (1988–2006), and 532 extracardiac conduits (1997–2010). The proportion with hypoplastic left heart syndrome increased from 1/173 (1%) before 1990 to 80/500 (16%) after 2000. Survival at 10 years was 89% (84%–93%) for AP and 97% (95% confidence interval [CI], 94%–99%) for lateral tunnels and extracardiac conduits. The longest survival estimate was 76% (95% CI, 67%–82%) at 25 years for AP. AP independently predicted worse survival compared with extracardiac conduits (hazard ratio, 6.2; P<0.001; 95% CI, 2.4–16.0). Freedom from failure (death, transplantation, takedown, conversion to extracardiac conduits, New York Heart Association III/IV, or protein-losing enteropathy/plastic bronchitis) 20 years after Fontan was 70% (95% CI, 63%–76%). Hypoplastic left heart syndrome was the primary predictor of Fontan failure (hazard ratio, 3.8; P<0.001; 95% CI, 2.0–7.1). Ten-year freedom from failure was 79% (95% CI, 61%–89%) for hypoplastic left heart syndrome versus 92% (95% CI, 87%–95%) for other morphologies. Conclusions— The long-term survival of the Australia and New Zealand Fontan population is excellent. Patients with an AP Fontan experience survival of 76% at 25 years. Technical modifications have further improved survival. Patients with hypoplastic left heart syndrome are at higher risk of failure. Large, comprehensive registries such as this will further improve our understanding of late outcomes after the Fontan procedure.

High pressure balloon angioplasty for branch pulmonary artery stenosis: Early experience

OBJECTIVES The aim of this study was to evaluate the efficacy and safety of high pressure balloons (17 to 20 atm, Blue Max, Meditech) to dilate branch pulmonary artery stenosis. BACKGROUND The low success rate (50% to 60%) for angioplasty of branch pulmonary artery stenosis using low pressure balloons is due primarily to the inability to eliminate the balloon waist. Hence, higher inflation pressures may improve results. METHODS Hemodynamic and angiographic data from 52 patients (0.3 to 34.8 years old) who underwent high pressure balloon dilation of branch pulmonary artery stenosis between October 1990 and February 1992 were reviewed retrospectively, as were data from previous low pressure dilations in these patients. Common diagnoses included tetralogy of Fallot (n = 9), tetralogy of Fallot with pulmonary atresia (n = 23), single ventricle (n = 8) and isolated congenital pulmonary stenosis (n = 7). The 52 patients had 72 vessels dilated. Criteria for success were a > or = 50% increase in vessel diameter or a > 20% decrease in right ventricular to aortic pressure ratio. RESULTS Of 36 vessels with previously unsuccessful low pressure balloon dilation, 23 (63%) were successfully dilated with high pressure balloons. Of the 36 remaining vessels, 29 (81%) were successfully dilated with high pressure balloons. Factors associated with success were stenosis at a surgical anastomosis and disappearance of the balloon waist with dilation. Aneurysms developed in three vessels. Complications occurred in seven patients (13%); in two patients the distal pulmonary artery was perforated by a stiff guide wire, causing death in one. CONCLUSIONS Dilation of stenotic peripheral pulmonary arteries with high pressure balloons improves the success rate of angioplasty both in patients who have had unsuccessful dilation with a low pressure balloon and in those without previous attempted dilation.

Assessments of Right Ventricular Volume and Function Using Three-Dimensional Echocardiography in Older Children and Adults With Congenital Heart Disease: Comparison With Cardiac Magnetic Resonance Imaging

BACKGROUND The utility of three-dimensional echocardiography (3DE) for right ventricular (RV) assessment is uncertain in older children and adults with congenital heart disease (CHD), in whom the right ventricle is often dilated and dysfunction is common. METHODS RV assessments using 3DE were compared with manual tracing and automated border detection (ABD) with magnetic resonance imaging (MRI) as the reference method. Twenty-eight of 54 consecutive patients (52%; median age, 17 years) with CHD had adequate three-dimensional echocardiographic data sets for analysis. RESULTS There were wide ranges of RV size (mean RV end-diastolic volume index, 143 +/- 43 mL/m(2)) and function (mean RV ejection fraction [EF], 48 +/- 10%) on MRI. End-diastolic volume was underestimated on 3DE by 20% (P < .001) and to a greater degree in larger ventricles (P < .001). There was no significant difference in EF measurements between 3DE methods and MRI except for ABD (-2.6 +/- 6, P = .03). The mean analysis time for ABD was 5 minutes, compared with 19 minutes for manual tracing (P < .0001). CONCLUSION Approximately half the patients with CHD had adequate three-dimensional echocardiographic images. Three-dimensional echocardiography accurately estimated EF but underestimated volume, particularly when the right ventricle was dilated. ABD minimally underestimated EF but offered a significant reduction in analysis time.

Age-Related Changes in Myocardial Relaxation Using Three-Dimensional Tagged Magnetic Resonance Imaging

PURPOSE Marked changes in left ventricular diastolic filling occur with advancing age, but alterations in myocardial movement accompanying these findings have not been previously documented. We aimed to identify differences in myocardial motion during relaxation and diastole using magnetic resonance imaging (MRI), with tagging, which uniquely allows accurate, noninvasive assessment of myocardial movement in three dimensions. METHODS Tagged MRI images from two groups of normal individuals were analyzed using dedicated computer software to provide values for group comparison of apical rotation, torsion, and circumferential and longitudinal strain throughout the cardiac cycle. RESULTS The mean age of the younger group was 22 years, (n = 15) and that of the older group was 69 years, (n = 16). In the older group, peak apical rotation and torsion were increased during systole and significantly more apical rotation, torsion, circumferential, and longitudinal strain persisted during myocardial relaxation and diastole. In addition, peak normalized reversal of apical rotation was reduced (-5.1 +/- 1.2 degrees s-1 vs. -6.7 +/- 1.2 degrees s-1, p = 0.001), and there were slower peak rates of circumferential lengthening (76.2 +/- 28% s-1 vs. 142.5 +/- 17% s-1, p < 0.001) and longitudinal lengthening (62.7 +/- 21% s-1 vs. 122.5 +/- 20% s-1, p < 0.001). CONCLUSIONS Tagged MRI is a unique, noninvasive imaging method that can identify significant prolongation and reduction of myocardial relaxation in older compared with young normal individuals.

Pre-operative brain injury in newborn infants with transposition of the great arteries occurs at rates similar to other complex congenital heart disease and is not related to balloon atrial septostomy.

OBJECTIVES The goal of this study was to determine the prevalence and pattern of pre-operative brain injury in infants with transposition of the great arteries (TGA) compared with other complex congenital heart disease (CHD) and to define the risk of balloon atrial septostomy (BAS) for the development of brain injury. BACKGROUND It has recently been suggested that infants with TGA are at increased risk of pre-operative brain injury, in particular, stroke, and that this is strongly associated with having a BAS. METHODS Sixty-four newborn infants with TGA (n = 44), hypoplastic left heart syndrome (n = 13), or pulmonary atresia (n = 7) had magnetic resonance imaging (MRI) scans performed before surgery. RESULTS Thirty-three (75%) of the infants with TGA had a BAS. Brain injury occurred in 19 (30%) infants: white matter injury (WMI) in 17 (27%), and stroke in 3 (5%). There was no difference in the prevalence or pattern of brain injury between diagnostic groups. There was no association between BAS and brain injury in infants with TGA. There was a trend toward increased brain injury in TGA with an intact interventricular septum compared with TGA with a ventricular septal defect (38% vs. 8%, p = 0.075). There was no association between brain injury and any clinical variables. CONCLUSIONS Pre-operative brain injury on MRI scan was present in 30% of infants with CHD. The predominant pattern was WMI. The rates and patterns of pre-operative brain injury are similar in infants with TGA compared with other complex CHD, and BAS does not increase the risk of pre-operative brain injury.

Predictors of long-term survival with Ebstein's anomaly of the tricuspid valve

In patients with Ebsteins anomaly of the tricuspid valve, predictors of death and indications for surgery are poorly defined. We retrospectively reviewed 48 patients with Ebsteins anomaly, 17 (35%) of whom presented in the first week of life. Duration of follow-up extended to 32 years (greater than 10 years in 35%). Twenty of the 48 patients (42%) died, 6 in the first week of life and 1 at age 5 months. Thirteen of the 41 patients surviving to age 6 months subsequently died, 50% probability of survival being reached at 47 years. Significant (p less than or equal to 0.05) predictors of death in this group were: male sex, cardiothoracic ratio greater than or equal to 0.65, New York Heart Association class III or IV, breathlessness and the absence of Wolff-Parkinson-White syndrome. Eight patients died suddenly. A cardiothoracic ratio greater than or equal to 0.65 was a better predictor of sudden death than functional status. All who developed atrial fibrillation died within 5 years. Other atrial arrhythmias were not helpful in predicting sudden death. In view of these findings, tricuspid valve surgery is recommended before the cardiothoracic ratio reaches 0.65, regardless of the symptomatic state.

Long-term outcome in patients with pacemakers following the fontan operation*

Patients with pacemakers after Fontan surgery compared favorably with nonpaced patients with respect to survival. In patients with atrioventricular block, dual chamber pacing was superior to VVI pacing.