Roberta G. Williams

Isolated noncompaction of left ventricular myocardium. A study of eight cases.

Isolated noncompaction of left ventricular myocardium is a rare disorder of endomyocardial morphogenesis characterized by numerous, excessively prominent ventricular trabeculations and deep intertrabecular recesses. This study comprised eight cases, including three at necropsy. Ages ranged from 11 months to 22.5 years, with follow-up as long as 5 years. Gross morphological severity ranged from moderately abnormal ventricular trabeculations to profoundly abnormal, loosely compacted trabeculations. Echocardiographic images were diagnostic and corresponded to the morphological appearances at necropsy. The depths of the intertrabecular recesses were assessed by a quantitative echocardiographic X-to-Y ratio and were significantly greater than in normal control subjects (p less than 0.001). Clinical manifestations of the disorder included depressed left ventricular systolic function in five patients, ventricular arrhythmias in five, systemic embolization in three, distinctive facial dysmorphism in three, and familial recurrence in four patients. We conclude that isolated noncompaction of left ventricular myocardium is a rare if not unique disorder with characteristic morphological features that can be identified by two-dimensional echocardiography. The incidence of cardiovascular complications is high. The disorder may be associated with facial dysmorphism and familial recurrence.

Partial Fontan: Advantages of an adjustable interatrial communication☆

Systemic venous hypertension after the Fontan procedure is a major cause of mortality and morbidity, accounting for 11 of 16 deaths in our series of 228 Fontan procedures. A partial Fontan with a residual atrial septal defect (ASD) would allow controlled right-to-left shunting to reduce venous pressure and improve cardiac output while maintaining a reduced but acceptable arterial oxygen saturation. This allows complete or graded closure of the ASD after the discontinuation of cardiopulmonary bypass in the operating room or at any time in the postoperative period by exposing the snare under local anesthesia. From 1987 to 1990, 36 patients undergoing the modified Fontan procedure had placement of an adjustable interatrial communication. Indications for placement of an adjustable ASD included increased pulmonary artery pressures, increased pulmonary vascular resistance, reactive airway disease, previously increased or unknown pulmonary vascular resistance, small pulmonary arteries, and borderline ventricular function. Fourteen patients had the adjustable ASD closed at the time of operation, 8 patients underwent narrowing, and 12 underwent closure of the ASD in the postoperative period. Eight patients were discharged with the ASD partially open, and 2 patients underwent delayed closure. The partial Fontan with an adjustable ASD may increase the safety of the Fontan procedure for high-risk groups such as those with increased pulmonary vascular resistance, pulmonary hypertension, and impaired left ventricular function and for infants, who tolerate venous hypertension poorly. The ability to adjust the ASD in stages depending on the hemodynamic response increases flexibility and safety.

Conversion of atriopulmonary to cavopulmonary anastomosis in management of late arrhythmias and atrial thrombosis

The original atriopulmonary connection or classic Fontan operation is associated with several late complications such as arrhythmias, right atrial dilatation, and thromboembolism. This report describes our experience with 3 patients who presented with the acute onset of atrial arrhythmias and upon further evaluation were found to have significant hemodynamic lesions. After failing medical management, all 3 patients were treated successfully with surgical conversion of their atriopulmonary connection to a lateral tunnel cavopulmonary Fontan. The postoperative course of these patients was uneventful. However, long-term evaluation is needed to assess the efficacy of this technique in the prevention of postoperative morbidity.

Total cavopulmonary anastomosis versus conventional modified Fontan procedure

The total cavopulmonary anastomosis, lateral tunnel Fontan, has been advocated as a preferred method for Fontan type repair. From 1987 to July 1990, 39 patients underwent total cavopulmonary anastomoses (group 1) and 39 patients underwent modified Fontan procedures (group 2); patients receiving adjustable atrial septal defects were excluded. Diagnoses in group 1 included tricuspid atresia in 5 patients, single ventricle in 32, and pulmonary atresia and intact ventricular septum in 2. Diagnoses in group 2 included tricuspid atresia in 20, single ventricle in 17, hypoplastic left heart syndrome in 1, and pulmonary atresia and intact ventricular septum in 1. There were no significant differences in age, weight, cross-clamp time, duration of inotropic support, postoperative effusions, or hospital stay between the two groups. Early mortality in group 1 was 7.7% (3/39) and in group 2, 2.6% (1/39). There was no difference in the incidence of early dysrhythmias or early pacemaker placement. Late mortality was 2.8% in group 1 and 8% in group 2 with a mean follow-up of 18 and 25 months, respectively. Follow-up in group 1 revealed 33 patients in normal sinus rhythm and 1 patient with episodes of supraventricular tachycardia; no additional patients have required pacemakers. Follow-up in group 2 revealed 27 patients in normal sinus rhythm and supraventricular tachycardia in 4 patients; 5 additional patients have required pacemaker placement. There is no apparent difference in early outcome between the total cavopulmonary anastomosis and the conventional modified Fontan. However, there appears to be an increased incidence of late dysrhythmias and the need for pacemaker placement in the conventional modified Fontan group compared with the lateral tunnel group.

Factors influencing survival in patients undergoing the bidirectional Glenn anastomosis

The bidirectional Glenn anastomosis (BGA) has long been used as a surgical intervention for patients with single ventricle physiology. Initially, this procedure was the final stage in palliation and was performed in older children. Eventually, as the Fontan procedure came to be used as a method to separate circulations, the Glenn procedure was performed as an intermediate step. Over time, the BGA was performed as an alternative for patients who were considered to be at high risk with the Fontan procedure. Between January 1, 1988, and January 1, 1994, 129 patients underwent BGA at the University of California-Los Angeles. These patients were reviewed retrospectively, including clinic visits, catheterization, and echocardiographic information. The overall survival rate was 87% (112 of 129 patients). The average length of follow-up was 27 months. This information was then analyzed by univariate and multivariate analysis. Several factors were related to failure in patients who underwent BGA including pulmonary artery pressure, systemic right ventricle, and presence of anomolous pulmonary venous drainage and heterotaxy syndrome.

Factors influencing survival of patients with heterotaxy syndrome undergoing the Fontan procedure

OBJECTIVESnThis study was undertaken to determine those factors that may influence survival in patients with heterotaxy syndrome undergoing the Fontan procedure.nnnBACKGROUNDnThe Fontan procedure remains the preferred palliative procedure for patients with heterotaxy syndrome. Although the mortality rate has improved for patients without this syndrome undergoing the Fontan procedure, it remains high for patients with heterotaxy syndrome.nnnMETHODSnThe medical records of 20 consecutive pediatric patients with asplenia (n = 12) and polysplenia (n = 8) who underwent the Fontan procedure between January 1, 1986 and December 31, 1990 were reviewed. Anatomic and hemodynamic data were collected, as well as data on types of surgical palliative procedures and on outcome of the Fontan procedure.nnnRESULTSnThere were two early and two late deaths for a total mortality rate of 20% in the patients with heterotaxy syndrome, as compared with 8.5% for the patients without this syndrome who underwent the Fontan procedure during the same time period. Factors that significantly increased the risk of the Fontan procedure in these patients were 1) preoperative findings of greater than mild atrioventricular valve regurgitation, b) hypoplastic pulmonary arteries, and c) mean pulmonary artery pressure greater than or equal to 15 mm Hg after 6 months of age. Systemic and pulmonary venous anomalies coupled with single-ventricle anatomy were not significant risk factors for determining a poor outcome of the Fontan procedure.nnnCONCLUSIONSnThis study suggests that the outcome of the Fontan procedure in patients with heterotaxy syndrome may be improved by early protection of the pulmonary vascular bed, despite the existence of other cardiac anomalies.

Systemic venous and pulmonary arterial flow patterns after Fontan's procedure for tricuspid atresia or single ventricle.

Despite increasing use of Fontan or modified Fontan repairs, the comparative hemodynamic efficacy of different types of connections are unresolved. Accordingly, we undertook a prospective study designed to determine postoperative flow patterns after Fontans operation. Seven subjects had tricuspid atresia and eight had single ventricle. Ages ranged from 5 to 38 years (mean 16.4). Ten subjects had nonvalved right atrial-to-pulmonary arterial connection, and four had nonvalved right atrial-to-right ventricular communication. A valved conduit established continuity between the right atrium and right ventricle in one subject. Doppler flow profiles were recorded in the pulmonary artery and in the superior and inferior venae cavae of each. A reference electrocardiogram was used for timing purposes. In 14 patients, forward flow in the pulmonary artery was biphasic. Flow began at the end of the T wave (early ventricular diastole), peaked at or before the P wave (atrial systole), and returned to baseline by the peak of the R wave. Forward flow recommenced at the peak of the R wave (ventricular systole) and returned to baseline at the end of the T wave. Flow in the superior vena cava varied, and could not be recorded in three subjects. Between the end of the P wave and peak of the R wave (atrial systole) flow was reversed in eight, absent in three, and forward in one patient. Forward flow occurred between the peak of the R wave and the end of the T wave and was either continuous or biphasic. Fourteen patients had adequate studies of inferior vena cava flow; reversed flow during atrial systole occurred in 10 subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of banding of the pulmonary trunk with single ventricle physiology at risk for subaortic obstruction

This study addresses the effects of early banding of the pulmonary trunk and subsequent management of subaortic obstruction on the attainment of acceptable pre-Fontan hemodynamics in patients with a single left ventricle and aorta arising from an outflow chamber. We report our experience with 26 patients seen at our institution between January 1984 and December 1994 with a diagnosis of double-inlet left ventricle or tricuspid atresia and transposed great arteries, who were initially managed with pulmonary artery banding in the first 6 months of life. Pulmonary artery band placement was performed at an age of 2.1 +/- 1.8 months (mean +/- SD). Associated aortic arch abnormalities were present in 8 patients (31%). There were 19 patients (73%) who underwent treatment with a Damus-Kaye-Stansel procedure or ventricular septal defect (VSD) enlargement for a significant subaortic gradient or morphologically small VSD, alone or in conjunction with a Glenn or Fontan procedure. Eighteen of 26 patients (69%) underwent cardiac catheterization to assess their candidacy for the Fontan operation. Of this group, 16 were classified as low to moderate risk and 2 as high-risk Fontan candidates, based on hemodynamic criteria. The cumulative mortality for the entire cohort was 19%. Our results suggest that this high-risk group of patients can undergo effective pulmonary artery banding as an initial palliative step, with subsequent intervention for subaortic ob- struction when it is documented or highly suspected, and that acceptable pre-Fontan hemodynamic parameters can be achieved.

Repair of truncus arteriosus in infancy

Improvements in myocardial protection, surgical technique, and postoperative care have decreased operative mortality for neonatal repair of truncus arteriosus. Primary repair of truncus arteriosus in infancy without prior pulmonary artery banding is currently the preferred approach. During the period from 1982 to December 1990, 32 patients under the age of 12 months underwent surgical correction of truncus arteriosus at UCLA. The average age was 3.5 months (range, 12 days to 12 months). Three patients had interrupted aortic arch. Early mortality for the entire group was 15.6% (5/32); for those older than 1 month early mortality was 7% (2/28). In the past 4 years, early mortality has decreased to 8.3% (2/24); both of these patients had interrupted aortic arch. Excluding patients with interrupted aortic arch, there were no early deaths in the last 22 patients (1986 to 1990). Late mortality overall was 7.4% (2/27). In a mean follow-up of 73 months (range, 40 to 110 months), 71% (5/7) of the survivors with Dacron porcine-valved conduits required conduit replacement secondary to obstruction. In a mean follow-up of 36 months (range, 1 to 89 months), only 14% (3/21) of the patients with homografts required replacement secondary to obstruction.

Effectiveness of the bidirectional Glenn shunt procedure for volume unloading in the single ventricle patient.

Abstract The decisions for timing and type of surgical intervention in patients with a single ventricle who have significant risk factors for poor Fontan outcome are a continuing challenge. Often, these patients may be deferred further surgical intervention for a prolonged period of time because of their risk factors. The bidirectional Glenn shunt has been shown to be a very useful staging procedure for such patients.1 It offers the benefit of providing flow to the pulmonary arteries without adding additional volume burden to the ventricle. In this study we retrospectively analyzed both the volume and mass changes that occur perioperatively when patients with single ventricle physiology undergo a bidirectional Glenn shunt procedure, as well as the effects of age, preoperative oxygen saturation, preoperative hemoglobin, atrioventricular valve regurgitation, and mild systemic outflow obstruction upon these changes.