Mary E. van der Velde

Balloon Dilation of Severe Aortic Stenosis in the Fetus Potential for Prevention of Hypoplastic Left Heart Syndrome: Candidate Selection, Technique, and Results of Successful Intervention

Background—Preventing the progression of fetal aortic stenosis (AS) to hypoplastic left heart syndrome (HLHS) requires identification of fetuses with salvageable left hearts who would progress to HLHS if left untreated, a successful in utero valvotomy, and demonstration that a successful valvotomy promotes left heart growth in utero. Fetuses meeting the first criterion are undefined, and previous reports of fetal AS dilation have not evaluated the impact of intervention on in utero growth of left heart structures. Methods and Results—We offered fetal AS dilation to 24 mothers whose fetuses had AS. At least 3 echocardiographers assigned a high probability that all 24 fetuses would progress to HLHS if left untreated. Twenty (21 to 29 weeks’ gestation) underwent attempted AS dilation, with technical success in 14. Ideal fetal positioning for cannula puncture site and course of the needle (with or without laparotomy) proved to be necessary for procedural success. Serial fetal echocardiograms after intervention demonstrated growth arrest of the left heart structures in unsuccessful cases and in those who declined the procedure, while ongoing left heart growth was seen in successful cases. Resumed left heart growth led to a 2-ventricle circulation at birth in 3 babies. Conclusions—Fetal echocardiography can identify midgestation fetuses with AS who are at high risk for developing HLHS. Timely and successful aortic valve dilation requires ideal fetal and cannula positioning, prevents left heart growth arrest, and may result in normal ventricular anatomy and function at birth.

Pregnancy outcomes after the Fontan repair

OBJECTIVES This study sought to determine risks and outcome of pregnancy and delivery after the modified Fontan operation. BACKGROUND Increasingly, female Fontan patients reaching child-bearing years are interested in having children. To date, the number of reported pregnancies is small, and pregnancy has therefore been discouraged. METHODS One hundred ten of 126 female patients from the Fontan registries of the Mayo Clinic and University of California Los Angeles Medical Center responded to a mailed questionnaire. An additional six patients with a reported pregnancy from other centers were identified and reviewed to assess pregnancy outcomes. RESULTS Among the participating centers, a total of 33 pregnancies after Fontan operation for various types of univentricular heart disease were reported. There were 15 (45%) live births from 14 mothers, with 13 spontaneous abortions and 5 elective terminations. In the 14 women with live births, the median number of years between operation and pregnancy was 4 (range 2 to 14). Reported prepregnancy problems in these gravidas included atrial flutter in one patient and ventricular dysfunction, aortic regurgitation and atrioventricular valve regurgitation in another. One patient developed supraventricular tachycardia during pregnancy and had conversion to sinus rhythm. No maternal cardiac complications were reported during labor, delivery or the immediate puerperium. There were six female and nine male infants (mean gestational age 36.5 weeks; median weight 2,344 g). One infant had an atrial septal defect. At follow-up, mothers and infants were alive and well. CONCLUSIONS Pregnancy after the Fontan operation appears to have been well tolerated in 13 to 14 gravidas. There does appear to be an increased risk of miscarriage. The tendency to routinely discourage pregnancy may need to be reconsidered.

Creation of an Atrial Septal Defect In Utero for Fetuses With Hypoplastic Left Heart Syndrome and Intact or Highly Restrictive Atrial Septum

Background—Infants born with hypoplastic left heart syndrome and an intact or highly restrictive atrial septum face a neonatal mortality of at least 48% despite early postnatal left atrial decompression and palliative surgery. Prenatal left atrial decompression has been suggested as a means of improving these outcomes. This study reports the feasibility of fetal catheterization to create an interatrial communication and describes technical considerations. Methods and Results—Seven fetuses at 26 to 34 weeks’ gestation with hypoplastic left heart syndrome and intact or highly restrictive atrial septum underwent attempted prenatal intervention. Under ultrasound guidance, the atrial septum was approached with a needle introduced percutaneously from the maternal abdominal surface. In 6 of 7 fetuses, the atrial septum was successfully perforated, with balloon dilation of this iatrogenic defect resulting in a small but persistent interatrial communication. There were no maternal complications. One fetus died after the procedure. The remaining fetuses were liveborn at term, although 4 died as neonates. Conclusions—Ultrasound-guided fetal atrial septoplasty consisting of septal puncture and balloon dilation is feasible and can be performed percutaneously to minimize maternal risk. Although we have not demonstrated any positive clinical impact to date, it is our hope that further technical evolution will ultimately enable prenatal left atrial decompression and improvement of outcomes in fetuses with hypoplastic left heart syndrome and intact atrial septum.

Hypoplastic left heart syndrome with intact or highly restrictive atrial septum: Outcome after neonatal transcatheter atrial septostomy

Background—Hypoplastic left heart syndrome (HLHS) with intact or very restrictive atrial septum is a highly lethal combination. We review our 13-year institutional experience treating this high-risk subgroup of patients with emergent catheter therapy. Methods and Results—Infants with HLHS requiring catheter septostomy within the first 2 days of life were compared with a matched control group with adequate interatrial communication. Preoperative, early postoperative, and medium-term survival were evaluated. Earlier experience was compared with recent results to assess the effect of changes in catheterization and surgical and intensive care unit management strategies over the study period. From 1990 to 2002, 33 newborns with HLHS (11% of newborns with HLHS managed during this period) underwent urgent/semiurgent catheterization to create or enlarge an interatrial communication before surgical palliation. Preoperative and early postoperative mortality were high (48%) compared with control HLHS patients, regardless of prenatal diagnosis and despite successful catheter-based atrial septostomy with clinical stabilization. Mortality trended down during the later part of the study period. Those who survived the neonatal period had late survival, pulmonary artery pressure, and resistance similar to those of control subjects. Conclusions—Neonatal mortality in the subgroup of HLHS patients with intact or highly restrictive atrial septum remains high despite successful urgent septostomy. Persistently poor outcomes for these patients have prompted efforts at our center to develop techniques for fetal intervention for this condition, in the hope that prenatal relief of left atrial and pulmonary venous hypertension may promote normal pulmonary vascular and parenchymal development and improve both short- and long-term outcomes.

Sevoflurane Depresses Myocardial Contractility Less than Halothane during Induction of Anesthesia in Children

Background Cardiovascular stability is an important prerequisite for any new volatile anesthetic. We compared echocardiographically derived indices of myocardial contractility during inhalation induction with sevoflurane and halothane in children. Methods Twenty children were randomized to receive either halothane or sevoflurane for inhalation induction of anesthesia. No preoperative medications were given. Myocardial contractility was evaluated at baseline and at sevoflurane and halothane end-tidal concentrations of 1.0 minimum alveolar concentration (MAC) and 1.5 MAC. Results There were no differences between groups in patient age, sex, physical status, weight, or height. Equilibration times and MAC multiples of sevoflurane and halothane were comparable. Vital signs remained stable throughout the study. Left ventricular end-systolic meridional wall stress increased with halothane but remained unchanged with sevoflurane. Systemic vascular resistance decreased from baseline to 1 MAC and 1.5 MAC with sevoflurane. Halothane depressed contractility as assessed by the stress-velocity index and stress-shortening index, whereas contractility remained within normal limits with sevoflurane. Total minute stress and normalized total mechanical energy expenditure, measures of myocardial oxygen consumption, did not change with either agent. Conclusions Myocardial contractility was decreased less during inhalation induction of anesthesia with sevoflurane compared with halothane in children. Although the induction of anesthesia with sevoflurane or halothane was equally well tolerated, the preservation of myocardial contractility with sevoflurane makes it an attractive alternative for inducing anesthesia in children.

Video-assisted thoracoscopic surgery for congenital heart disease

Video-assisted endoscopic techniques have reduced operative trauma in adult thoracic and general surgery, but applications in children with congenital heart disease have been limited. We report the development of video-assisted thoracic surgery procedures for neonates and infants with cardiovascular disease. Endoscopic instruments and techniques for pediatric cardiovascular procedures were designed and tested in the animal laboratory. Forty-eight operations were subsequently performed in 46 pediatric patients ranging in age from 2 hours to 14 years (median 9 months), weighing from 575 grams to 54 kg (median 8.5 kg). Clinical applications included seven different surgical procedures: patent ductus arteriosus interruption in infants (n = 26) and premature neonates (n = 5), vascular ring division (n = 8), pericardial drainage and resection (n = 3), arterial and venous collateral interruption (n = 2), thoracic duct ligation (n = 2), epicardial pacemaker lead insertion (n = 1), and diagnostic thoracoscopy (n = 1). There was no operative mortality. Technical success, defined as a video-assisted procedure completed without incising chest wall muscle or spreading the ribs, was achieved in 39 of 48 procedures (82%), with thoracotomy required to complete nine procedures. Most patients (22/25, 88%) undergoing elective ductus ligation were extubated in the operating room and discharged from the hospital within 48 hours of the operation. Eight of the last 10 patients having ductus ligation were discharged on the first postoperative day. Residual ductal flow was assessed by (1) transesophageal echocardiography in the operating room (incidence: 0/25, 0%, 70% CL 0% to 7.3%); (2) discharge auscultation (incidence: 1/30, 3%, 70% CL 0.5% to 10.8%); and (3) follow-up Doppler echocardiography (incidence: 3/25, 12%, 70% CL 5.4% to 22.6%). Video-assisted thoracoscopic techniques can be safely applied to pediatric patients with patent ductus arteriosus and vascular rings and may become an effective addition to the staged management of more complex forms of congenital heart disease.

Prenatal Features of Ductus Arteriosus Constriction and Restrictive Foramen Ovale in d-Transposition of the Great Arteries

BACKGROUND Although most neonates with d-transposition of the great arteries (TGA) have an uncomplicated preoperative course, some with a restrictive foramen ovale (FO), ductus arteriosus (DA) constriction, or pulmonary hypertension may be severely hypoxemic and even die shortly after birth. Our goal was to determine whether prenatal echocardiography can identify these high-risk fetuses with TGA. METHODS AND RESULTS We reviewed the prenatal and postnatal echocardiograms and outcomes of 16 fetuses with TGA/intact ventricular septum or small ventricular septal defect. Of the 16 fetuses, 6 prenatally had an abnormal FO (fixed position, flat, and/or redundant septum primum). Five of the 6 had restrictive FO at birth. Five fetuses had DA narrowing at the pulmonary artery end in utero, and 6 had a small DA (diameter z score of <-2.0). Of 4 fetuses with the most diminutive DA, 2 also had an abnormal appearance of the FO, and both died immediately after birth. One other fetus had persistent pulmonary hypertension. Eight fetuses had abnormal Doppler flow pattern in the DA (continuous high-velocity flow, n=1; retrograde diastolic flow, n=7). CONCLUSIONS Abnormal features of the FO, DA, or both are present in fetuses with TGA at high risk for postnatal hypoxemia. These features may result from the abnormal intrauterine hemodynamics in TGA. A combination of restrictive FO and DA constriction in TGA may be associated with early neonatal death.

Association between cardiac tumors and tuberous sclerosis in the fetus and neonate

A retrospective review was performed in 94 patients with > or =1 cardiac tumors seen on prenatal or neonatal echocardiography at 5 major referral centers. Tuberous sclerosis was present in 68 patients diagnosed with a cardiac tumor in utero or during the neonatal period, including 61 of 64 with multiple tumors.

Bulboventricular foramen size in infants with double-inlet left ventricle or tricuspid atresia with transposed great arteries: influence on initial palliative operation and rate of growth.

Bulboventricular foramen obstruction may complicate the management of patients with single left ventricle. Bulboventricular foramen size was measured in 28 neonates and infants greater than 5 months old and followed up for 2 to 5 years in those patients whose only systemic outflow was through the foramen. The bulboventricular foramen was measured in two planes by two-dimensional echocardiography, its area calculated and indexed to body surface area. One patient died before surgical treatment. The mean initial bulboventricular foramen area index was 0.94 cm2/m2 in 12 patients (Group A) in whom the foramen was bypassed as the first procedure in early infancy. The remaining 15 patients underwent other palliative operations but the bulboventricular foramen continued to serve as the systemic outflow tract. There was one surgical death. Six (Group B) of the 14 survivors developed bulboventricular foramen obstruction during follow-up (mean initial bulboventricular foramen area index 1.75 cm2/m2). The remaining eight patients (Group C) did not develop obstruction during follow-up and had an initial bulboventricular foramen larger than that in the other two groups (mean initial bulboventricular foramen area index 3.95 cm2/m2). All patients with an initial bulboventricular foramen area index less than 2 cm2/m2 who did not undergo early bulboventricular foramen bypass developed late obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary echocardiography in 406 patients with d-loop transposition of the great arteries

OBJECTIVES The reliability of two-dimensional echocardiography for determining the proximal coronary artery anatomy in d-loop transposition of the great arteries was investigated in 406 infants who underwent surgical repair at one institution. BACKGROUND The origin and proximal course of the main coronary arteries can affect the surgical results of the arterial switch operation. Preoperative determination of the coronary artery anatomy appears to be advantageous for the surgeon. METHODS All infants with d-loop transposition who underwent a two-dimensional echocardiogram and primary surgical repair at our institution between 1987 and 1992 were identified, and the echocardiographic, operative and, when available, autopsy reports were reviewed for coronary artery anatomy, presence of a ventricular septal defect and the spatial relation between the arterial roots. The two-dimensional echocardiographic findings were compared with surgical or autopsy findings. The relation between proximal coronary artery anatomy and 1) a ventricular septal defect, and 2) the spatial orientation of the arterial roots was investigated. Twenty-seven infants diagnosed with an intramural coronary artery were not included because they are the subjects of another report. RESULTS Excluding intramural coronary artery patterns, 10 different types of coronary artery anatomy were seen in these 406 patients. The coronary arteries were imaged adequately in 387 (95%) of the 406 patients. The coronary artery anatomy was determined correctly by two-dimensional echocardiography in 369 (95.4%) of the 387 patients, with 18 errors in diagnosis. During the most recent 2.5 years, 193 (98.5%) of 196 patients were diagnosed correctly, with three diagnostic errors. Patients with a ventricular septal defect or side-by-side great arteries are more likely to have an unusual coronary pattern. CONCLUSIONS Echocardiography appears to be highly reliable for determining proximal coronary artery anatomy in d-loop transposition of the great arteries. An unusual coronary artery pattern is more likely in patients with side-by-side great arteries or posterior aorta or a ventricular septal defect, or both.