Achi Ludomirsky

Double balloon technique for dilation of valvular or vessel stenosis in congenital and acquired heart disease

Despite the generally excellent success with balloon dilation for the stenotic lesions of congenital and acquired heart disease, technical difficulties sometimes prevent satisfactory results. Such technical difficulties include: a large diameter of the anulus of the stenotic lesion relative to available balloon diameter, difficulty in the insertion or removal of the larger balloon catheters, and permanent damage to or obstruction of the femoral vessels by the redundant deflated balloon material of the large balloons. A double balloon technique was initiated to resolve these difficulties. With this method, percutaneous balloon angioplasty catheters were inserted in right and left femoral vessels, placed side by side across the stenotic lesion and inflated simultaneously. Dilation procedures using the two balloon technique were performed in 41 patients: 18 with pulmonary valve stenosis, 14 with aortic valve stenosis, 5 with mitral valve stenosis, 3 with vena caval obstruction following the Mustard or Senning procedure and 1 with tricuspid valve stenosis. Patient ages ranged from 1 to 75 years (mean 17.8) and patient weights ranged from 8.9 to 89 kg (mean 42.3). Balloon catheter sizes ranged from 10 to 20 mm in diameter. Average maximal pressure gradient in mm Hg before dilation was 61 in pulmonary stenosis, 68 in aortic stenosis, 21 in mitral stenosis, 12 in tricuspid stenosis and 25 in vena caval stenosis. Average maximal valvular pressure gradient after dilation was 13 in pulmonary stenosis, 24 in aortic stenosis, 4 in mitral stenosis, 0 in tricuspid stenosis, and 1 in vena caval stenosis. No major complications were encountered with the procedures.(ABSTRACT TRUNCATED AT 250 WORDS)

Follow-up of coil occlusion of patent ductus arteriosus

OBJECTIVE We sought to determine the prevalence and fate of residual ductal shunting following coil occlusion of patent ductus arteriosus. BACKGROUND Although transcatheter coil occlusion of patent ductus arteriosus has gained popularity, few follow-up data have been reported. METHODS A review of 75 patients who underwent coil occlusion was performed. Residual shunting was investigated by Doppler echocardiography in follow-up. Angiograms were reviewed to obtain minimal ductal diameter and ductal angiographic type. RESULTS Residual shunts were found in 31 patients (41%) on the day of the procedure, and of these, spontaneous closure was noted in 17 (55%) at 2 weeks to 20 months of follow-up. Of the 75 patients studied, 5 (7%) required a second coil procedure, and 10 (13%) remained with persistent residual shunts at most recent follow-up. Actuarial analysis estimated a 6 +/- 5% prevalence of residual shunts 20 months after a single coil procedure and 3 +/- 3% after all coil procedures. Minimal ductal diameter was associated with immediate complete ductal occlusion by a single coil. These patients had significantly smaller (p = 0.003) minimal ductal diameters (1.2 +/- 0.7 mm) than those who required two coils during their initial procedure to achieve immediate occlusion (1.9 +/- 0.7 mm), those who required a second coil procedure (2.0 +/- 0.9 mm), those who had spontaneous closure of residual shunts (1.9 +/- 0.7 mm) and those with persistent residual shunts (2.0 +/- 0.9 mm). No association was identified between ductal angiographic type and outcome of coil occlusion. No late adverse clinical events of coil occlusion or evidence of recanalization was found. CONCLUSIONS Small residual shunts are common after coil embolization of patent ductus arteriosus, but most close spontaneously. Actuarial analysis estimates complete closure in 94% at 20 months, and reintervention was required in only 7% of patients.

Noninvasive Creation of an Atrial Septal Defect by Histotripsy in a Canine Model

Background— The primary objective of this study was to develop an image-guided, noninvasive procedure to create or enlarge an atrial septal defect for the treatment of neonates with hypoplastic left heart syndrome and an intact or restrictive atrial septum. Histotripsy is an innovative ultrasonic technique that produces nonthermal, mechanical tissue fractionation through the use of high-intensity ultrasound pulses. This article reports the pilot in vivo study to create an atrial septal defect through the use of extracardiac application of histotripsy in an open-chest canine model. Methods and Results— In 10 canines, the atrial septum was exposed to histotripsy by an ultrasound transducer positioned outside the heart. Ultrasound pulses of 6-microsecond duration at a peak negative pressure of 15 MPa and a pulse repetition frequency of 3.3 kHz were generated by a 1-MHz focused transducer. The procedure was guided and monitored by real-time ultrasound imaging. In 9 of 10 canines, an atrial septal defect was produced, and shunting across the atrial septum was visualized. Pathology of the hearts showed atrial septal defects with minimal damage to surrounding tissue. No damage was found on the epicardial surface of the heart or other structures. Conclusions— Under real-time ultrasound guidance, atrial septal defects were successfully created with extracardiac histotripsy in a live canine model. Although further studies in an intact animal model are needed, these results provide promise of histotripsy becoming a valuable clinical tool.

Critical aortic stenosis in the neonate: A comparison of balloon valvuloplasty and transventricular dilation

The optimal treatment of critical aortic stenosis in the neonate and infant remains controversial. We compared transventricular dilation using normothermic cardiopulmonary bypass and percutaneous balloon aortic valvuloplasty with respect to early and late survival, relief of aortic stenosis, degree of aortic insufficiency, left ventricular function, and freedom from reintervention. Between July 1987 and July 1993, 30 neonates and infants underwent transventricular dilation or balloon aortic valvuloplasty for critical aortic stenosis. The patients in the transventricular dilation group (n = 21) ranged in age from 1 to 59 days (mean age 18.0 days +/- 19.1 days) and the balloon aortic valvuloplasty group (n = 9) from 1 to 31 days (mean age 10.0 days +/- 9.0 days). There were no significant differences in weight, body surface area, or aortic anulus diameter between the two groups (p = 1.0). Associated cardiovascular anomalies were more common in the transventricular dilation group (48%) than in the balloon aortic valvuloplasty group (11%). After intervention, the degree of residual aortic stenosis and insufficiency was equivalent in the two groups as assessed by postprocedural Doppler echocardiography. Ejection fraction improved within both groups (transventricular dilation 39% +/- 20.2% versus 47% +/- 22.0%; balloon aortic valvuloplasty 51% +/- 16.1% versus 62% +/- 8.4%), and there was no significant difference between groups. The left ventricular mass/volume ratio increased within both groups (p < 0.05) but with no significant difference between groups (transventricular dilation 1.4 +/- 0.5 gm/ml versus 1.8 +/- 0.6 gm/ml; balloon aortic valvuloplasty 1.1 +/- 0.6 gm/ml versus 1.7 +/- 0.4 gm/ml). Early mortality in the transventricular dilation group was 9.5% and in the balloon aortic valvuloplasty group, 11.1%. There was one late death in the transventricular dilation group. Four patients from the transventricular dilation group (19%) and two patients from the balloon aortic valvuloplasty group (22%) required reintervention for further relief of aortic stenosis. We conclude that both transventricular dilation and balloon aortic valvuloplasty provide adequate and equivalent relief of critical aortic stenosis. The treatment strategy adopted should depend on other factors, including associated cardiovascular anomalies, vascular access, preoperative condition, and the technical expertise available at each institution.

The pediatric pulmonary and cardiovascular complications of vertically transmitted human immunodeficiency virus (P2C2 HIV) infection study: Design and methods

The P2C2 HIV Study is a prospective natural history study initiated by the National Heart, Lung, and Blood Institute in order to describe the types and incidence of cardiovascular and pulmonary disorders that occur in children with vertically transmitted HIV infection (i.e., transmitted from mother to child in utero or perinatally). This article describes the study design and methods. Patients were recruited from five clinical centers in the United States. The cohort is composed of 205 infants and children enrolled after 28 days of age (Group I) and 612 fetuses and infants of HIV-infected mothers, enrolled prenatally (73%) or postnatally at age < 28 days (Group II). The maternal-to-infant transmission rate in Group II was 17%. The HIV-negative infants in Group II (Group IIb) serves as a control group for the HIV-infected children (Group IIa). The cohort is followed at specified intervals for clinical examination, cardiac, pulmonary, immunologic, and infectious studies and for intercurrent illnesses. In Group IIa, the cumulative loss-to-follow-up rate at 3 years was 10.5%, and the 3-year cumulative mortality rate was 24.9%. The findings will be relevant to clinical and epidemiologic aspects of HIV infection in children.

Continuous-wave Doppler in children with ventricular septal defect: Noninvasive estimation of interventricular pressure gradient

Continuous-wave Doppler was used to estimate the pressure gradient between the right and left ventricles in 28 children with ventricular septal defect (VSD). Doppler measurement of maximal velocity was performed during cardiac catheterization and the Doppler-predicted gradient was compared with the peak-to-peak gradient measured simultaneously by catheter. Doppler gradients ranged from 10 to 71 mm Hg and correlated well with measured gradient (r = 0.97, p greater than or equal to 0.001). Fourteen patients had isolated VSD, and in these patients Doppler measurements of gradient allowed accurate estimation of right ventricular pressure (r = 0.93). There was an inverse correlation between the ratio of pulmonary to systemic resistance and maximal velocity (r = -0.77). Thus, continuous-wave Doppler is an accurate means of measuring instantaneous VSD pressure gradient in children with congenital heart disease and can be used to estimate the right ventricular and pulmonary artery pressure in children with isolated VSD. This noninvasive method can be used to distinguish restrictive from nonrestrictive VSD.

Pulmonary venous and systemic ventricular inflow obstruction in patients with congenital heart disease: Detection by combined two-dimensional and Doppler echocardiography

Obstruction to pulmonary venous return may be associated with a number of congenital cardiovascular abnormalities occurring both before and after surgery. Hemodynamic assessment by cardiac catheterization is often difficult. A noninvasive method for detection and quantitation of obstruction to systemic ventricular inflow would be clinically useful. Two-dimensionally directed pulsed and continuous wave Doppler echocardiography was performed before cardiac catheterization in 31 patients thought clinically to have possible obstruction to left ventricular inflow or pulmonary venous return. Primary diagnoses included transposition of the great arteries after the Mustard or Senning procedure in nine patients, total anomalous pulmonary venous connection in nine (in two after surgical repair), cor triatriatum in eight (in four after surgical repair), congenital mitral stenosis in four (in one after surgical repair) and mitral atresia in one. Severe obstruction was defined as a mean pressure gradient at catheterization of greater than or equal to 16 mm Hg at any level of the pulmonary venous return or of the systemic ventricular inflow. Severe obstruction was predicted if Doppler examination measured a flow velocity of greater than or equal to 2 m/s across any area of inflow obstruction. At catheterization, 12 patients (39%) had severe obstruction to left ventricular inflow or pulmonary venous return and all obstructions were correctly detected by Doppler echocardiography. The site of pulmonary venous obstruction was localized by two-dimensionally directed pulsed Doppler study. Patients with a lesser degree of obstruction had a lower Doppler velocity, but none had a maximal Doppler velocity of greater than or equal to 2 ms/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Color Doppler detection of multiple ventricular septal defects.

Combined two-dimensional and Doppler echocardiography has a high sensitivity and specificity for detection of isolated perimembranous ventricular septal defects. However, muscular or multiple ventricular septal defects may be difficult to diagnose with noninvasive methods, particularly in older children, necessitating angiography for accurate diagnosis. Detection of single and multiple ventricular septal defects with two-dimensional color flow mapping was compared with detection by standard two-dimensional imaging and Doppler. Both techniques were compared with four-chamber left ventricular angiography. Fifty-one patients (age 3 months to 25 years, mean 5.6 years) were studied. Eighteen had solitary ventricular septal defects, 18 had multiple ventricular septal defects, and 15 patients with intact ventricular septum served as a control group. At least one ventricular septal defect was detected by color Doppler and two-dimensional/Doppler methods in all patients with ventricular septal defect proved by angiography with no false positives. In the detection of multiple ventricular septal defects, the sensitivity of color Doppler was 72% and that of two-dimensional/Doppler was 38% (100% specificity in both). Color Doppler failed to identify multiple ventricular septal defects in five patients (two weighing less than 4 kg and three with reduced pulmonary blood flow). However, no large additional muscular defects were missed by imaging and color Doppler. Color Doppler is useful for the detection of ventricular septal defects and has higher sensitivity than two-dimensional/Doppler for multiple ventricular septal defects. The contribution of color Doppler appears to be in the detection of additional small muscular ventricular septal defects.

Modified Norwood operation for single left ventricle and ventriculoarterial discordance: an improved surgical technique.

BACKGROUND Patients with univentricular hearts and ventriculoarterial discordance with potentially obstructed systemic blood flow continue to pose difficult management problems. The goals of neonatal palliative operations are to control pulmonary blood flow while avoiding pulmonary artery distortion, to relieve systemic outflow tract obstruction, and to avoid heart block. METHODS Between January 1987 and December 1996, 38 patients with either tricuspid atresia or a double-inlet left ventricle and ventriculoarterial discordance underwent a modified Norwood procedure. Their mean age was 15 days, and their mean weight was 3.4 kg. Aortic arch anomalies were present in 92% of the patients. Morbidity and mortality statistics, intraoperative data, and postoperative echocardiograms were reviewed. RESULTS There were 3 early deaths (7.8%) and 5 late deaths (13.1%). The actuarial survival rates at 1 month, 1 year, and 5 years were 89%, 82%, and 71%, respectively. Follow-up was complete in all children at a mean interval of 30 +/- 9 months. None of the patients had significant neoaortic valve insufficiency, and 1 patient required therapy for residual aortic arch obstruction. Nine patients (30% of the survivors) have undergone the hemi-Fontan procedure, and 18 patients (60%) successfully have undergone the Fontan procedure. CONCLUSIONS In this patient population, we recommend the modified Norwood procedure as the neonatal palliative treatment of choice. It can be performed with acceptable early morbidity and mortality, and it improves suitability for the Fontan procedure. It reliably relieves all levels of systemic outflow tract obstruction, controls pulmonary blood flow, and avoids heart block.

Results of balloon valvuloplasty in typical and dysplastic pulmonary valve stenosis: Doppler echocardiographic follow-up

To assess the usefulness of balloon valvuloplasty in patients with a dysplastic pulmonary valve, the files of 36 patients (aged 1 day to 18.5 years) who had two-dimensional echocardiography before and continuous wave Doppler echocardiography late after balloon valvuloplasty (balloon diameter greater than or equal to 20% anulus diameter) were reviewed. Results of relief of pulmonary stenosis were graded by catheter gradient in the catheterization laboratory and compared with Doppler echocardiographic findings at follow-up. There were 32 patients with typical pulmonary stenosis and 4 with a dysplastic valve. In the 32 patients with typical pulmonary stenosis, transvalvular gradient changed from a mean of 67 +/- 32 to 20 +/- 20 mm Hg (p less than 0.0001, mean reduction 72.6%). The gradients at follow-up by Doppler echocardiography averaged 20 mm Hg including 15 that increased, 3 that were unchanged and 14 that decreased. Only 3 (9%) of 32 patients had a gradient greater than 25 mm Hg at follow-up and only one gradient was greater than 35 mm Hg. All four patients with a dysplastic valve had a gradient that decreased with valvuloplasty from a mean of 85 +/- 33 to 33 +/- 20 mm Hg (p less than 0.05); gradient reduction in this group ranged from 40 to 85% (mean 57.5%). The gradient at follow-up increased in three of these four patients and decreased in one (the only late gradient less than 25 mm Hg). Late gradient was less than 35 mm Hg in two of the four patients and was reduced by 43 and 57%, respectively, in the other two.(ABSTRACT TRUNCATED AT 250 WORDS)