Early and late results of the modified Fontan procedure for double-inlet left ventricle: the Mayo Clinic experience

Between May 1974 and March 1989, 155 patients with double-inlet left ventricle had the Fontan procedure performed at the Mayo Clinic. Age at operation ranged from nearly 2 to 41 years (median 10). The operative mortality rate from 1974 through 1980 (39 patients) was 21%, but from 1981 through 1989 (116 patients) it was reduced to 9%. The 17 late deaths were secondary to reoperation (n = 8), progressive myocardial failure (n = 5), sudden arrhythmia (n = 3) and bleeding varices (n = 1). Neither operative nor late mortality rate was significantly related to age at operation. At follow-up of 6 months to 11 years (mean 4.9 years) in 111 patients, 88% were in good or excellent condition and 12% were in fair or poor condition. The Fontan operation can be performed with a mortality risk of less than 10% in properly selected patients with double-inlet left ventricle. Late results are encouraging when contrasted with the clinical course of patients before this operative approach was utilized.

MR imaging of partial anomalous pulmonary venous connections

Magnetic resonance imaging was performed on 11 patients with partial anomalous pulmonary venous connections (PAPVC). Ten of these patients also had echocardiographic examinations, eight of which included color-flow Doppler studies. The diagnosis of PAPVC was confirmed in each of these patients by surgery or angiography. Fourteen anomalous pulmonary venous connections were identified, 10 involving the right upper lobe pulmonary vein and 4 involving the left upper lobe pulmonary vein. This retrospective review demonstrated that all 14 anomalous venous connections were correctly identified by MR imaging, whereas only 8 of 13 (62%) were identified by echocardiography. With MR, 89% of all the pulmonary veins and 93% of the anomalous pulmonary veins were visualized on axial images, while 41% of all pulmonary veins and 71% of anomalous veins were seen on coronal MR images. There were five atrial septal defects (ASDs), four of the sinus venous type and one of the septum secundum type. All five ASDs were correctly identified with MR imaging; three of four ASDs were identified with echocardiography. We conclude that MR imaging provides an accurate noninvasive method of depicting the anatomic abnormalities associated with PAPVC.

Tissue characterization of an unusual right atrial mass by magnetic resonance imaging

In a 70-year-old man who had angina, exercise-induced ventricular tachycardia, and presyncopal symptoms, transthoracic and transesophageal echocardiography disclosed a large atrial mass that resembled a myxoma. Subsequent evaluation by magnetic resonance imaging identified the mass as an intracardiac lipoma attached to the posterior wall of the right atrium, a diagnosis that was confirmed by surgical intervention. Thus, the diagnostic utility of magnetic resonance imaging as an adjunct to echocardiographic evaluation of intracardiac masses was demonstrated.

Repair of transposition of the great arteries with intact ventricular septum and left ventricular outflow tract obstruction

Repair of transposition of the great arteries in patients with intact ventricular septum and fixed left ventricular outflow tract obstruction has been restricted to atrial baffle procedures, with or without attempts to relieve or bypass the left ventricular outflow obstruction. However, the suboptimal results of these procedures, coupled with excellent functional results with the arterial switch operation in patients without obstruction, has made anatomic correction the goal in repairing these anomalies. We report a technique for the anatomic correction of transposition of the great arteries, intact ventricular septum, and fixed left ventricular outflow tract obstruction. Its consideration in these difficult cases is advocated.

A modification of the Fontan procedure incorporating anomalies of systemic and pulmonary venous return

A modification of the Fontan procedure is described in which separation of anomalous systemic and pulmonary venous pathways is accomplished without the need for construction of a complex intraatrial baffle. The feasibility of this simplified surgical technique is predicated on the presence of a left superior vena cava draining to a coronary sinus. The design of the procedure and results in two patients with polysplenia syndrome and a constellation of systemic and pulmonary venous anomalies are presented. Early and late results have been gratifying, and continued exploration of the technique seems warranted.

MR imaging of fat in and around the heart

MR imaging is useful for characterizing collections of fat in and around the heart. This article illustrates the MR appearance of pericardial fat, epicardial and periaortic fat, intramural fatty involvement and intracavitary fat, with emphasis on the distinctions between fatty and nonfatty tumors.

Effect of pulsed progressive fluoroscopy on reduction of radiation dose in the cardiac catheterization laboratory

The increased application of therapeutic interventional cardiology procedures is associated with increased radiation exposure to physicians, patients and technical personnel. New advances in imaging techniques have the potential for reducing radiation exposure. A progressive scanning video system with a standard vascular phantom has been shown to decrease entrance radiation exposure. The effect of this system on reducing actual radiation exposure to physicians and technicians was assessed from 1984 through 1987. During this time, progressive fluoroscopy was added sequentially to all four adult catheterization laboratories; no changes in shielding procedures were made. During this time, the case load per physician increased by 63% and the number of percutaneous transluminal coronary angioplasty procedures (a high radiation procedure) increased by 244%. Despite these increases in both case load and higher radiation procedures, the average radiation exposure per physician declined by 37%. During the same time, the radiation exposure for technicians decreased by 35%. Pulsed progressive fluoroscopy is effective for reducing radiation exposure to catheterization laboratory physicians and technical staff.

Truncus arteriosus revisited: an angiographic demonstration

The 1965 reclassification of truncus arteriosus by Van Praagh and Van Praagh greatly enhanced our understanding of this interesting anomaly. This brief review article attempts to illustrate the various types of truncus arteriosus identified in this classification by demonstrating their angiographic features. Reemphasis of the usefulness of this classification should help students of congenital heart disease recognize the advantages of a uniform diagnostic approach to this entity.

Complete repair of pulmonary atresia, ventricular septal defect, and severe peripheral arborization abnormalities of the central pulmonary arteries. Experience with preliminary unifocalization procedures in 38 patients

From 1982 to 1987, 38 consecutive patients with pulmonary atresia and ventricular septal defect underwent staged unifocalization procedures in preparation for final intracardiac repair of the anomaly. Thirty-six patients had concordant visceroatrial, atrioventricular, and ventriculoarterial connections. A central pulmonary artery confluence was present in 19 patients and absent in the remaining group. All patients with central pulmonary arteries had inadequate peripheral pulmonary arterial arborization. Systemic collateral arteries were present in all 38 patients. The objectives of the unifocalization procedures were the interruption of extracardiac sources of pulmonary arterial blood flow, the restoration of segmental, lobar, and pulmonary arterial confluence, the replacement of missing central pulmonary arterial branches, and the creation of a central, accessible source of pulmonary arterial blood flow. A total of 54 unifocalization procedures were performed in the 38 patients. These procedures included 85 permanent connecting anastomoses, 15 temporary anastomoses to the ascending aorta, 13 angioplasty procedures, and 15 modified Blalock-Taussig shunts. Three patients died after unifocalization (two early and one late). By the end of the study, eight patients were still waiting for further unifocalization procedures or angiographic assessment. Four patients were rejected for further surgical treatment because of persistent, uncorrectable defects of the pulmonary arterial arborization pattern. Twenty-three patients underwent complete intracardiac repair with two deaths (one early and one late). Postrepair, intraoperative right ventricular/left ventricular systolic pressure ratio after complete surgical repair ranged from 0.4 to 1.0 (mean = 0.63, standard deviation = 0.14). At the end of follow-up, 21 survivors of complete repair were free of significant symptoms. Unifocalization procedures designed to improve the pulmonary arterial arborization pattern of patients with pulmonary atresia and ventricular septal defect with or without central pulmonary arteries can prepare a significant number of these patients for successful intracardiac repair of the anomaly.

Extracardiac vasculature in candidates for Fontan surgery: MR imaging

Magnetic resonance (MR) imaging was performed in 53 patients considered to be candidates for a modified Fontan operation to repair cardiac or extracardiac vascular anomalies. The MR studies were reviewed retrospectively, and the findings with regard to the extracardiac vascular anatomy were compared with the findings from angiography or surgery. The accuracy of MR for the correct identification of the systemic veins was 98%; for pulmonary arteries, 97%; and for pulmonary veins, 95%. For identification of pulmonary veins, MR imaging had a sensitivity of 90% and a specificity of 100%. MR provides excellent demonstration of the extracardiac vascular structures, which are of particular importance in patients being considered for a Fontan procedure.

Optimal display of the coronary arterial tree with an upscan 1,023-line video display system

Differences of opinion exist as to whether visualization of the coronary arterial tree is better with 525-line or 1,023-line video imaging systems. The 1,023-line acquisition has been associated with image degradation; 525-line display, however, has prominent raster lines that may also degrade the image. For evaluation of this issue, identical coronary arterial images were obtained with 525-line acquisition and then displayed with either 525-line or 1,023-line display. The 525-line acquisition with digital upscan 1,023-line display had superior image quality compared with 525-line display. With the use of 525-line acquisition and 1,023-line display, video images were similar to or slightly better than the identical cineangiographic images.

Magnetic resonance imaging of the heart: current status

The favorable technical capabilities of magnetic resonance imaging (MRI) make it well suited for delineating the heart and great vessels. The clinical applications of cardiac MRI have gradually expanded in the past several years. Currently, the most important applications use the modality to provide detailed morphologic information, especially about surgical lesions of the heart. Particularly noteworthy have been applications of MRI in preoperative assessment of patients with certain types of congenital heart disease, cardiac masses, and lesions of the great vessels. Other roles for the modality such as in functional cardiac imaging and nuclear magnetic resonance spectroscopy remain attractive, but these have not yet entered the domain of routine clinical practice.

Caveats of balloon dilation of conduits and conduit valves

The results and complications of percutaneous balloon dilation involving 10 patients with a stenotic right ventricle to pulmonary artery prosthetic conduit and 1 patient with an obstructed right atrium to left pulmonary artery Dacron graft (modified Fontan) are reported. For the 10 patients (14.5 +/- 5 years) with a right ventricle to pulmonary artery conduit, the mean (+/- SD) predilation conduit valve gradient was 57 +/- 22 mm Hg, right ventricular pressure 104 +/- 21 mm Hg and right ventricle to pulmonary artery gradient 75 +/- 23 mm Hg; 2 of the patients had additional pulmonary artery stenosis requiring dilation. In one patient, the balloon could not be advanced across the conduit valve. In 9 of 10 patients in whom dilation was successfully performed, the conduit valve gradient decreased by 59 +/- 13%, right ventricle to pulmonary artery gradient by 43 +/- 22% and right ventricular pressure by 31 +/- 11%. After dilation, right ventricular pressure was less than 65% of systemic pressure in seven patients, although no pressure was less than 40%. In 8 of the 11 patients, surgery was avoided or postponed. Complications included loss of a balloon fragment after rupture during the unsuccessful dilation of the right atrium to left pulmonary artery graft and circumferential balloon rupture requiring catheter retrieval of the distal portion of the balloon from the femoral vein after successful dilation of the right ventricle to pulmonary artery conduit. Conduit valve dilation by balloon can reduce but rarely eliminate conduit obstruction, and balloon rupture may occur and can result in fragment loss or embolization.

Congenital absence of the pericardium and its relationship to the ligamentum arteriosum

An anatomic and embryologic study of congenital absence of the pericardium and the relationship of the ligamentum arteriosum to this defect was carried out by the authors. A case report is presented to clinically correlate the anatomic and radiologic findings in this anomaly. The authors propose that visualization of the ligamentum arteriosum by computed tomography is a characteristic sign for congenital absence of the left pericardium.

Cardiac masses: assessment by MR imaging

The purpose of this study was to assess the role of MR imaging for evaluating suspected cardiac tumors or paracardiac masses involving the heart. Sixty-one patients with clinical or radiologic evidence of cardiac masses were imaged with ECG-gated MR at 1.5 T (22 patients) or 0.15 T (39 patients). Fifty-one patients had echocardiography previously. Among the tissue diagnoses were myxoma (six); fibroma, rhabdomyoma, plasma cell granuloma, lipomatous hypertrophy of the atrial septum, mesothelioma, and thymoma (two each); and leiomyosarcoma, lymphoma, metastatic carcinoid, melanoma, malignant fibrous histiocytoma, hemangiopericytoma, and lung spindle cell sarcoma (one each). MR imaging demonstrated masses in 50 patients (82%); they were centered in the heart in 32, pericardial in nine, and juxtacardiac in nine. MR imaging provided diagnostic information that affected clinical management or surgical planning in 53 patients (87%), including 11 (18%) in whom cardiac mass was excluded by MR. The ability to provide a global view of cardiac anatomy and other unique capabilities of MR imaging give the procedure an important role in the diagnosis and preoperative assessment of cardiac masses.

Accuracy of two-dimensional echocardiography in diagnosing left superior vena cava

Seventy-three consecutive patients with a left superior vena cava evaluated at the Mayo Clinic, Rochester, Minnesota, between 1983 and 1987 underwent cardiac catheterization and two-dimensional echocardiography. Bilateral superior venae cavae were present in 89%. Entry of the left superior venae cavae was into the coronary sinus in 62% (4% were unroofed), a pulmonary venous atrium in 21%, and a common atrium in 17%. Catheterization successfully identified the left superior vena cava in all patients; two-dimensional echocardiography was successful in 68% (group 1) and unsuccessful in 32% (group 2). There was no significant difference between groups with regard to age, sex, diagnosis, or site of drainage. In group 1, 43% had a dilated coronary sinus; in group 2, the coronary sinus was present in 61% but was of normal size. Cineangiograms revealed smaller caliber left superior venae cavae in group 2 than in group 1 (means 7.4 and 11.3 mm, respectively). Thus two-dimensional echocardiography is not totally reliable for the detection of small but possibly significant left superior venae cavae.

The modified Fontan operation for asplenia and polysplenia syndromes

From 1975 through 1986, 49 patients with asplenia (23 patients) or polysplenia (26 patients) syndromes underwent a modified Fontan operation. All patients had anomalous systemic venous return, and 43 (88%) had anomalous pulmonary venous return. The atrioventricular valve anatomy varied: 36 patients had a common atrial chamber and common atrioventricular valve, eight had mitral valve atresia, and five had severe mitral valve hypoplasia. Redirection of systemic venous return was accomplished by (1) atrial baffle (29 patients), (2) intraatrial conduit (19 patients), and (3) extraatrial conduit (one patient). There were 21 (43%) hospital deaths overall. However, since 1985, six of 22 patients (27%) have died. Increased mortality was seen in patients requiring atrioventricular valve repair or replacement (8/11, 73%) and in patients with asplenia (65%). Lower mortality was seen in patients with polysplenia (24%) and those receiving an intraatrial conduit (26%), although this decrease also represents the more recent experience. We conclude: (1) The Fontan operation for patients with asplenia or polysplenia syndromes has resulted in a significant (although recently declining) mortality; (2) mortality is higher in patients with asplenia; (3) patients with atrioventricular valve insufficiency requiring repair or replacement are at higher risk; and (4) intraatrial conduits seem to offer promise for successfully accomplishing this repair.

Technical consideration for a new X-ray video progressive scanning system for cardiac catheterization

The widespread growth of interventional angiographic procedures has expanded the use of X-ray video systems. Reduced radiation exposure to the patient and staff has been recently reported by implementing a new pulsed progressive scanning video system. We have shown that this system, which enables the pulsing of the X-ray generator at 30 pulses per second, results in a 50% reduction in radiation exposure. The technical parameters and implementation of a progressive scanning video system are discussed. Image quality, temporal and spatial resolution, and signal-to-noise ratio (SNR) were assessed using conventional interlaced and progressive video scanning. These comparisons documented improved resolution, no degradation of ejection fraction measurements, improved clinical images, and a 1.0-dB improvement in the SNR with the progressive scanning. Progressive scanning video systems reduce radiation exposure and provide an objective improvement in image quality over conventional scanning video systems.

Blood velocity measurements during selective coronary angiography before and after percutaneous transluminal coronary angioplasty

The velocity of blood flowing down a coronary artery may provide an index of myocardial perfusion, independent of the need for measuring the amount of myocardium supplied by a vessel. The velocity of the leading edge of contrast material was therefore measured before and after percutaneous transluminal coronary angioplasty in 15 patients utilizing digitized images from routine coronary angiography. The velocity (mean +/- SD) before percutaneous transluminal coronary angioplasty in the 15 patients was 11.9 +/- 6.0 cm/s, increasing to 21.7 +/- 8.7 cm/s after (P less than 0.01). There was a correlation between the percent change in velocity and the change in percent stenosis before and after percutaneous transluminal coronary angioplasty (r = 0.65; P less than 0.001). The mean absolute interobserver and intraobserver variabilities for the velocity measurements were 2.1 and 1.8 cm/s, respectively. Measurement of coronary flow velocity from data obtained at the time of routine coronary angiography is an easily performed reproducible technique, which may be used to assess the results of an intervention such as percutaneous transluminal coronary angioplasty.

Right ventricular outflow construction without cardiopulmonary bypass

Establishment of right ventricular-pulmonary arterial continuity without the use of cardiopulmonary bypass was undertaken in 36 patients with different anomalies associated with pulmonary atresia or severe stenosis. Hospital mortality was 11% with no late death. Fourteen of the 27 individuals with pulmonary atresia, ventricular septal defect, and hypoplastic confluent pulmonary arteries had adequate angiographic follow-up, which demonstrated significant pulmonary artery enlargement. Five patients underwent total correction, two after unifocalization operations to establish lobar pulmonary arterial continuity. Symmetric growth of the left and right pulmonary artery was not achieved. However, the enlargement was adequate for potential final repair in all the patients with an unrestricted outflow tract.

Correlation between magnetic resonance imaging of the heart and cardiac anatomy

An understanding of anatomy forms the cornerstone for accurate interpretations of pathologic alterations. In this article, we present cardiac magnetic resonance images and the corresponding sections of normal hearts obtained at autopsy and cut in planes parallel and perpendicular to the ventricular septum in addition to the standard anatomic orthogonal planes (coronal, sagittal, and transverse). This correlation demonstrates the ability of magnetic resonance imaging to display cardiac anatomy accurately and noninvasively. Because magnetic resonance imaging provides excellent contrast between flowing blood and cardiac walls and has the capacity to provide direct images in multiple planes without inherent difficulties, this procedure has advantages over other currently available imaging techniques.

Definitive operation for pulmonary atresia with intact ventricular septum. Results in twenty patients

Definitive operation was performed on 20 patients (aged 25 to 178 months) with pulmonary atresia and intact ventricular septum. All patients had one or more prior preliminary palliative procedures. Right ventricular outflow tract reconstruction with atrial septal defect closure and shunt removal was done on 10 patients. Tricuspid annular circumference was at least 70% of normal in seven patients and between 55% and 70% in three patients. Two patients died during hospitalization. The eight surviving patients were asymptomatic 3 to 145 months after operation. The modified Fontan operation was performed on 10 patients. None of these patients had a tricuspid annular circumference greater than 70% of normal; the circumference was less than 55% in nine patients and between 55% and 70% in one patient. One patient died during hospitalization and one died later. Follow-up 6 to 48 months after operation showed that six patients were in the New York Heart Association Class I and two were in Class II. After effective preliminary palliation of pulmonary atresia with intact ventricular septum, definitive operation can be done with an operative risk of 15% (three of 20 patients) and excellent late results. Right ventricular outflow tract reconstruction can be done as a complete repair for patients who have adequate tricuspid annular size. The modified Fontan operation is the only option for definitive repair when the tricuspid anulus is severely hypoplastic.