Total cavopulmonary connection.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M R de Leval.
Explore the source record for details and available documents.
The clinical presentation, diagnosis, and surgical treatment of 63 patients with doubly committed subarterial ventricular septal defects (DCVSD) were analyzed retrospectively. The patients were divided into three groups. Thirty-one patients had severe congestive heart failure in infancy and presently have a large ventricular septal defect that has no tendency to close or to produce aortic valve regurgitation (Group 1). Ideally, these defects should be closed in infancy, and the transpulmonary approach is recommended to achieve closure. In the first group, there was one death in a patient with a hypoplastic right ventricle. In Group 2, nineteen patients had aortic valve prolapse or aortic valve regurgitation. The DCVSD were moderately large or small. A number of DCVSD in Group 2 patients had maintained the normal offsetting of the arterial valves. These defects must be closed by the time mild aortic valve regurgitation has occurred. In Group 2, there was one late death in a patient who developed subacute bacterial endocarditis. The two patients who had severe aortic valve regurgitation required aortic valve replacement and underwent multiple surgical procedures to replace calcified bioprostheses. Group 3 comprised 13 patients who were diagnosed with tetralogy of Fallot. All of these patients had a large DCVSD with aortic valve overriding. All Group 3 patients survived radical repair of the defect, which required a transannular patch in most cases (76%).
Between 1979 and 1986, 26 patients with pulmonary atresia, ventricular septal defect, and multifocal pulmonary blood supply underwent surgery (median age, 2 years) to reconnect major aortopulmonary collateral arteries to other collateral arteries or to the central pulmonary arteries in an attempt to prepare the pulmonary circulation for complete repair. In four patients, central pulmonary arteries were found to be absent at exploratory thoracotomy, and therefore, the surgery aimed for optimal palliation. Four (15%) patients died perioperatively. The survivors had symptomatic improvement. At restudy 1 week-110 months (median time, 25 months) postoperatively, modest growth of central pulmonary arteries had occurred [right plus left pulmonary artery diameters/descending aortic diameter from 0.64 +/- 0.61 (mean +/- SD) preoperatively to 0.95 +/- 0.60 postoperatively (p less than 0.01)], with a greater number of bronchopulmonary segments connected to central pulmonary arteries [from 6.3 +/- 4.8 preoperatively to 10.0 +/- 4.5 postoperatively (p less than 0.001)]. However, only seven (27%) patients met the established criteria for repair, of whom three (12%) have undergone definitive surgery. Thirteen (50%) patients are unsuitable for repair, and two (8%) await restudy. Failure of anastomoses involving major aortopulmonary collateral arteries (13 of 33) was higher than for grafts from a systemic artery to the central pulmonary artery (1 of 22, p = 0.003). Failure was not related to the number of anastomoses per operation, suggesting that poor distal runoff may have been responsible. This surgical approach provided reasonable palliation but was rarely effective as a prelude to complete repair.(ABSTRACT TRUNCATED AT 250 WORDS)
To understand better the contribution of a right atrium in a valveless atriopulmonary connection, we performed some basic hydrodynamic studies. Pulsation of a valveless chamber in a simple continuous flow circuit was found to generate turbulence and thereby to increase resistance to net forward flow. Visualization of flow through cavities and around corners and measurements of energy losses across nonpulsatile cavities, corners, and stenoses indicated the importance of streamlining. These studies suggested ways in which hydrodynamic designs of the Fontan circulation might be improved. In parallel with these in vitro studies, we have developed a modified approach to Fontan reconstruction that entails exclusion of most or all of the right atrium (total cavopulmonary connection). The operation consists of three parts: (1) end-to-side anastomosis of the superior vena cava to the undivided right pulmonary artery; (2) construction of a composite intraatrial tunnel with the use of the posterior wall of the right atrium; and (3) use of a prosthetic patch to channel the inferior vena cava to the enlarged orifice of the transected superior vena cava that is anastomosed to the main pulmonary artery. The operation was performed in 20 patients between March 1987 and March 1988. The diagnoses were double-inlet ventricle (11 patients), hypoplastic systemic or pulmonary ventricle (seven patients), and absent right atrioventricular connection (two patients). There were two early deaths and one late death. None of the deaths was related to the actual procedure but rather to increased pulmonary vascular resistance (two patients) or systemic ventricular failure (one patient). Total cavopulmonary connections have the following advantages: (1) They are technically simple and reproducible in any atrioventricular arrangement and are away from the atrioventricular node; (2) most of the right atrial chamber remains at low pressure, which reduces the risk of early or late arrhythmias; (3) reduction of turbulence prevents energy losses and should minimize the risk of atrial thrombosis; (4) postoperative cardiac catheterization performed in 10 patients confirmed these favorable flow patterns with minimal gradients throughout the connections. These encouraging early results support the continuing use of total cavopulmonary connection, at least for patients with a nonhypertrophied right atrium.
The response to intravenous administration of propranolol hydrochloride was studied in 24 children undergoing operation for isolated or complex right ventricular outflow tract obstruction. Ten had pulmonary valve stenosis, 4 had pulmonary valve stenosis plus ventricular septal defect, 8 had tetralogy of Fallot, and 2 had complex lesions. Propranolol (0.01 to 0.2 mg per kilogram of body weight) was given to patients with a residual right ventricular to left ventricular systolic pressure ratio greater than 0.75. Four children did not respond to propranolol and required further surgical intervention. Twenty patients responded, 2 of whom died. Fifteen were restudied by cardiac catheterization 3 weeks to 27 months postoperatively. The right ventricle-pulmonary artery gradient was 25 mm Hg or less in 13 patients. We conclude that a small dose of propranolol given intraoperatively can identify patients in whom a reduction in the right ventricle-pulmonary artery gradient to acceptable levels will occur in the months following operation. This may reduce the need for placement of a subannular or transannular patch in some patients.
Between 1971 and 1982, 249 patients received right heart extracardiac conduits. The 173 patients who survived 30 days were reviewed retrospectively; 72 had antibiotic-sterilized aortic homografts, 97 had xenografts of various types, and four had valveless tubes. Reoperation for conduit obstruction was required as early as 13 months after the original operation, but actuarial analysis showed no differences in overall performance of homograft and heterograft conduit groups with respect to late death or survival free of conduit obstruction. More important risk factors for late death or the need for reoperation were the severity of the underlying cardiac lesions and the influence of early postoperative complications. When analyzed statistically, the performance of conduits bearing homografts was disappointing, influenced sometimes by complications in the Dacron extension tubes. Repairs dispensing with conduits entirely should be evaluated.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Twenty-five autopsy specimens of complete transposition of the great arteries with intact ventricular septum (VS) were categorized as "bulging" (11 cases) or " nonbulging " (14 cases) according to the curvature of the VS. A fibrous ridge was observed on the VS, especially at the site of mitral apposition in 82% of the bulging group. No fibrous ridge was seen in the nonbulging group. An objective index of anteroposteriorness was then designed to measure the distance between the midpoint of the nonfacing aortic cusp line and the left anterior descending coronary artery. In the bulging group, the aorta lay more anterior to the pulmonary trunk, whereas in the hearts with a straight VS, the aorta tended to lie side by side and to the right of the pulmonary trunk. The midmitral line is an imaginary line in the middle of the anterior mitral leaflet. The more the pulmonary valve is wedged toward the right atrioventricular junction, the more the midmitral line will pass through the nonfacing pulmonary cusp rather than right pulmonary cusp or the nonfacing /right commissure. This was so in 100% of the bulging group, but in only 36% of the nonbulging group. These differences between the groups in terms of anteroposterior index and extent of wedging were statistically significant. In conclusion, if the aorta lies more anterior and to the left of pulmonary trunk rather than side by side and to the right, the "wedged" subpulmonary area will be more susceptible to obstruction caused by septal bulging. Cross-sectional echocardiography is the best means of diagnosing these features.
Between 1971 and 1980, 65 children, aged 2 weeks to 15 years (mean 6.8 years) had "fresh" antibiotic sterilized aortic homografts inserted as a valved external conduit. Thirty-six patients (55%) had undergone previous palliations. Operations were performed on cardiopulmonary bypass, with hypothermia and cardioplegia. In selected young infants, deep hypothermia with circulatory arrest was used. Twenty-five patients (38%) died after the operation. Mortality was related to the complexity of the lesion, the condition of the child on admission, and the degree of pulmonary vascular disease. In addition, there were 7 late deaths. Twenty-one patients were recatheterized, either as a part of routine postoperative assessment (13) or because of symptoms (8). Satisfactory conduit performance, judged by the absence of significant gradients or regurgitation, was found in 18 out of 21 restudied patients. Calcification of the homograft aortic wall was seen on chest X-ray in 56% of patients. The aortic valve calcified in only one child, following an episode of subacute bacterial endocarditis. We conclude that fresh antibiotic preserved aortic homografts perform well in extracardiac valved conduits. They are easy to insert and better hemostasis can be achieved. Degeneration of the valved leaflets is extremely rare.
Compensated right ventricular hypertrophy (RVH), defined by a greater than 100% RV weight increase compared to 17 normal animals, was created in 17 young pigs by pulmonary arterial banding. RVH was associated with significant elevations (p less than 0.001) in RV peak dP/dt, RV stroke work, RV minute work and RV rate-pressure product compared to normal animals matched by body weight. RV peak dP/dt showed a positive correlation (p less than 0.001) with RV peak systolic pressure in normals; however, this relationship was lost in banded animals since progressively higher RV pressures were not associated with concomitant increases in RV peak dP/dt, thus, suggesting an intrinsic difference between right and left ventricles when working at systemic arterial pressures. Time to RV peak dP/dt became progressively longer (p less than 0.05) as RV weight increased in the RVH animals. When indices of cardiac work were normalized for RV weight, the RVH group could not be distinguished from normals suggesting that the performance per unit weight of RV muscle in RVH was unchanged. Total RV blood flow, measured by radioactive microspheres, closely followed (p less than 0.001) increases in RV mass in banded animals. Blood flow . g-1 muscle in RV and septal right side were unaltered in RVH; however, regional perfusion of the left ventricle (p less than 0.001) and septal right side were unaltered in RVH; however, regional perfusion of the left ventricle (p less than 0.001) and septal left side (p less than 0.02) increased significantly. There were regional variations in RV perfusion which were maintained in compensated RVH; stress (isoprenaline infusion) caused significant increases in blood flow to all regions of the heart in normal and RVH animals (p less than 0.001), but relative regional distribution was maintained. Our observations suggest a relationship between myocardial work and blood flow in RVH such that RV perfusion . g-1 is elevated to meet haemodynamic requirements once RV regional work . g-1 become greater than normal.
Of 12 patients with angiographically absent pulmonary artery, 11 were investigated surgically. The previously occult pulmonary artery was found in 10 patients, in five of whom a vestige of an intrapericardial artery was present and in five the artery was patent only at the hilus, a gap existing between the main pulmonary artery and the hilar vessel, and no artery was found in one. All patients with an intrapericardial artery had right ventricular outflow tract obstruction and a ductus descending vertically from underneath the aortic arch. In those without an intrapericardial vessel the occult artery was on the side opposite the aortic arch, and there was evidence of a ductus coming from the innominate artery on the side of the interruption. The occult pulmonary artery, where identified at operation, was usually joined initially to the systemic circulation. Ultimately, continuity between the hilar and main pulmonary artery may be established surgically. Where no intrapericardial vessel exists, however, a conduit may be required to bridge the gap. It seems advisable to search for the occult artery as early in life as is feasible in the hope that providing a blood supply will ensure development of the vessel and normal lung growth.
To examine the effect of preoperative prostaglandin infusion on surgical mortality the records of all patients aged less than or equal to 28 days operated between January 1979 and December 1981 for obstructive lesions of the systemic circulation were reviewed. Forty patients had coarctation of the aorta, five interrupted aortic arch, and seven critical aortic stenosis. Fourteen patients received intravenous prostaglandin before operation. Among preoperative variables low cardiac output was identified as a possible risk factor for hospital death, whereas the presence of a raised blood urea concentration was possibly significantly associated with hospital mortality only in patients not treated with prostaglandin. The preoperative administration of prostaglandin had a strongly favourable influence: 11 out of 38 (29.0%) patients who did not receive prostaglandin died compared with none of 14 treated with prostaglandin. The two groups were otherwise comparable with respect to the incidence of coagulopathy, urgency of operation, associated anomalies, and other medical treatment. Mean age at operation was younger and mean admission blood urea concentration higher in the group treated with prostaglandin, whereas the incidence of preoperative low cardiac output was probably higher. It is concluded that short term preoperative infusion of prostaglandin in associated with a significant reduction in early surgical mortality in this high risk group of infants.
Critical aortic valvular stenosis presents in infancy with severe congestive heart failure. Clinical assessment and electrocardiography are of value, but cardiac catheterization with angiography has been considered mandatory prior to surgical treatment. With cross-section echocardiography an accurate diagnosis of aortic stenosis and associated lesions is possible. Over the past 2 years, we have established a protocol according to which, if a clinical diagnosis of critical aortic stenosis is confirmed by cross-sectional echocardiography in the absence of major associated cardiac anomalies, infants are submitted for aortic valvotomy under inflow occlusion without invasive studies. This protocol was used in an effort to decrease the mortality rate by avoiding the preoperative stress of cardiac catheterization and angiography, as well as the hazards of cardiopulmonary bypass in the severely ill infant. Eight infants with critical aortic stenosis have been operated upon, five without prior cardiac catheterization. Ages at operation ranged from 2 days to 7 months, with six children less than 2 weeks of age. The noninvasive diagnosis was confirmed at operation in each case. There was one early postoperative death and one late death. No death has been related to the technique of inflow occlusion. A decision tree for the noninvasive assessment of suspected critical aortic stenosis based on the clinical features and echocardiographic findings is presented.
Either right ventricular hypertrophy (RVH) or failure (RVF) was produced by pulmonary arterial banding in 47 piglets aged 3-6 weeks. When sufficient time was allowed to elapse after banding, RVH was present in 30 and had progressed to RVF in 17. These two groups were compared with 24 control, i.e., normal pigs (C). Animals with RVF differed from RVH and C animals by having reduced cardiac output and clinical signs of failure. Both RVH and RVF had significantly elevated right ventricular peak systolic pressures (RVS), weights (GMRV), and RV/LV systolic pressure ratios (these variables all increased greater than 100% compared with C). The RV (dP/dt)max correlated with RVS in C (r = 0.687, P less than 0.001), but this relationship was absent in RVH with higher RVS and GMRV. The RV (dP/dt)max correlated closely with RV blood flow/g per min in C (r = 0.638, P less than 0.01) and in RVH (r = 0.462, P less than 0.02). Calcium uptake by RV sarcoplasmic reticulum (SR) was diminished in RVH compared to C and further diminished in RVF (38%, P less than 0.001). Calcium uptake by LV SR also fell in RVF, suggesting that SR calcium uptake is merely a passive reflection of myocardial function. Our results also suggest that hemodynamic and subcellular changes seen in RVF may be detected during the compensated stage of RVH.
At the Hospital for Sick Children, London, between Jan. 1965 and Jan. 1980, 98 patients, ranging in age from 22 days to 20.8 years (mean = 29.6 months), with a clinical diagnosis of transposition of the great arteries (TGA) associated with a ventricular septal defect (VSD) found at cardiac catheterization, underwent Mustard procedure at the atrial level, whether or not associated with the VSD closure. Twenty-nine other patients, with irreversible obstructive pulmonary vascular disease in whom a "palliative" Mustard was performed, have been excluded from this report. At operation, in 8 cases, the VSD was found to have closed spontaneously during the interval between the cardiac catheterization and the surgical repair, while, in 13 patients, the VSD was judged to be too small to influence the hemodynamic results and, accordingly, was left open. In 35 cases the VSD was closed with mattress stitches buttressed with dacron pledgets and in 42 patients a dacron patch was used. The defects were accessible through the tricuspid valve in all but 10 cases. There were 24 early deaths (24%) and these did not correlate either with the year of operation or with the age at the time of operation. The mortality rate was higher in the cases who had required previous pulmonary artery banding (37%), than in those who had not (21.5%), but this difference was not statistically significant. The early results were related to the size of the VSD. In the 21 patients in whom the VSD was partially or completely closed, the early mortality was 9.5%.(ABSTRACT TRUNCATED AT 250 WORDS)
In order to study the usefulness of incorporating a subpulmonary ventricular chamber (SPVC) in the Fontan circulation, we compared the hemodynamics of 18 patients who underwent an atriopulmonary connection with those of 17 patients with an atrioventricular connection. Early postoperatively, regardless of whether an SPVC was incorporated or not, the mean pulmonary artery pressure was not higher than the mean right atrial pressure in any of our patients. The stroke work of the right heart was at best zero, and pressure tracings showed an a wave in the pulmonary artery (right atrium-dependent circulation). If an additional gradient was interposed between the right atrium and pulmonary artery, the effective stroke work of the right heart might be negative and the work curve have a negative slope. This can occur irrespective of the use of an SPVC. In the long term, if it grows sufficiently, an SPVC can sometimes provide a right ventricle-dependent pulmonary circulation with a more normal hemodynamic pattern (mean right atrial pressure less than mean pulmonary artery pressure). We concluded that an SPVC should be used in Fontan's circulation, provided that an obstruction-free atrioventricular connection can be established.
Explore the source record for details and available documents.