Long-term results after repair of complete atrioventricular septal defects: analysis of risk factors.

BACKGROUND: We analyzed data from 320 patients to evaluate the impact of different preoperative, operative, and postoperative factors on the outcome after repair of complete atrioventricular septal defect. METHODS: Between October 1974 and December 1995, 320 patients with complete atrioventricular septal defect not associated with major cardiac anomalies were operated on. Two hundred seventy-four patients underwent total repair. Sixty-three patients (23%) were less than 6 months old. One hundred ninety-eight (72.2%) underwent primary repair. Seventy-six patients (27.7%) had a previous palliative operation. RESULTS: Operative mortality in patients who underwent primary repair decreased from 17.6% (1974 to 1979) to 5.0% (1990 to 1995) despite an increase in the number of patients younger than 6 months. In patients undergoing a two-stage procedure operative mortality was 3.9% (late mortality, 7.9%). Young age (<6 months) was an incremental risk factor (p = 0.008) for operative mortality in the early study period. Coarctation of the aorta (p = 0.02) and severe dysplastic left atrioventricular valve (p = 0.001) were associated with a higher risk for operative mortality. Freedom from reoperation at 10 years was 82.5% +/- 3.8%. CONCLUSIONS: In patients with complete atrioventricular septal defect, primary repair is the treatment of choice and can be accomplished with good results. In our experience over a period of more than 20 years, earlier date of operation, young age (<6 months), dysplastic left atrioventricular valve, and coexisting coarctation were incremental risk factors for hospital death. The presence of a previously placed pulmonary artery band did not alter the outcome of repair. The reconstructed atrioventricular valve shows a good and long-lasting performance.

Results after surgical repair of Ebstein's anomaly.

BACKGROUND: Ebstein's anomaly of the tricuspid valve is a complex malformation. Various operations have been undertaken with varying results. Because valve replacement yielded poor results, surgical treatment has focused on valvuloplasties. METHODS: Between April 1974 and February 1995, 60 patients with Ebstein's anomaly underwent surgical repair. Age ranged from 5 months to 54 years. In 56 patients (93.3%), tricuspid valvuloplasty was feasible, mainly by creating a monocusp valve with the single-stitch technique. The other 4 patients had valve replacement with a bioprosthesis. Six reoperations were necessary (10.0%): four valve replacements and two repeat valvuloplasties. RESULTS: There were two hospital deaths (3.3%) and a late mortality rate of 10.0% (6 patients). Forty-nine (94.2%) of 52 survivors were followed for 5 months to 18.6 years (median follow-up, 5.0 years; mean follow-up, 6.9 years). The actuarial survival rate (Kaplan-Meier) was 96.5% +/- 2.4% at 1 year and 83.3% +/- 5.6% at 18 years. At follow-up evaluation, nearly all patients showed substantial improvement (93.9% were in functional class I or II) compared with their preoperative status. Doppler echocardiographic studies demonstrated good tricuspid valve function in most patients. CONCLUSIONS: Valvuloplasty using the single-stitch technique is a rewarding operation. It yields good long-term results with substantial improvement in functional performance and clinical status.

Congenital coronary artery fistula in infancy and childhood: diagnostic and therapeutic aspects.

Clinical symptoms and age at manifestation of a congenital coronary artery fistula may vary considerably. They depend on the underlying anatomy and also on the size of the fistulous connection to the left or right side of the heart. Using colour Doppler echocardiography for direct visualization of the entire course of the fistulous vessel, including the site of termination, succeeds only in a small number of cases. Furthermore, regular coronary vessels branching off proximally and distally of the coronary artery fistula usually are not recognizable by this method. Only selective angiography provides this information and is unchallenged the most important and indispensable diagnostic technique, especially with regard to surgical treatment. This publication presents physical, echocardiographic, and angiographic data of 15 patients, who were admitted to the German Heart Center Munich between 1970 and 1993. By an invasive diagnostic approach the following arteriovenous fistulous connections were found: from right coronary artery to right atrium (3 patients) or to right ventricle (3 patients), from left coronary artery to right atrium or coronary sinus (3 patients), from left coronary artery to right ventricle (4 patients) and from right and left coronary artery to right ventricle (2 patients). In 5 patients a "proximal" form of coronary artery fistula ("side-to-side pattern") was found, in 8 patients a "distal" form ("end-artery type"), and in 2 patients a combination of both forms. In 14 patients surgical closure was performed (6 symptomatic infants, mean age at surgery = 95 days, and 8 asymptomatic children, mean age at surgery = 7.1 years): 13 patients survived surgery. On an average of 5 years after surgery all of these 13 patients are in excellent condition (NYHA functional class I). The experiences in surgical treatment verify the importance of an exact angiographic visualization of the anatomy of a coronary artery fistula and the regular coronary vessels branching off proximally and distally of the fistula. Closure of coronary artery fistulas at the time of diagnosis is recommended also in asymptomatic patients, since perioperative morbidity and mortality increases in older patients.

Allograft implantation in pediatric cardiac surgery: surgical experience from 1982 to 1994.

Between July 1982 and April 1994, a total of 290 patients (median age 6.5 years, range 1 month to 32.1 years, 69 patients younger than 1 year) underwent repair of their cardiac malformation by insertion of an allograft. The diagnoses were truncus arteriosus communis (n = 78, 27.0%), tetralogy of Fallot (n = 59, 20.0%), pulmonary atresia (n = 72, 25.0%), double outlet right ventricle (n = 15, 5.0%), complex transposition of the great arteries plus pulmonary stenosis (n = 37, 13.0%), and others (n = 29, 10.0%). Either pulmonary (n = 69) or aortic (n = 221) cadaver allografts were implanted. Two hundred twenty-nine of the allografts were antibiotic preserved. Since January 1991 (n = 61), a new cryopreservation procedure was employed for standardized uniform cooling using heat sinks and defined package geometry. Follow-up was complete for 95.2% (n = 276, 1,320 patient-years). Thirty-day mortality was 9.0% (n = 26) and late mortality was 12.1% (n = 35). Kaplan-Meier analysis revealed that patient survival was determined mainly by their underlying cardiac disease. All allografts with valve sizes less than 15.0 mm had to be exchanged within 7 years as these patients had outgrown their conduits. When the allograft was larger than 15.0 mm, exchange was necessary in 20% at 10 years. ABO compatibility and aortic or pulmonary origin of the allograft were not significant influences on allograft survival.(ABSTRACT TRUNCATED AT 250 WORDS)

Bioprosthetic and mechanical valves in the elderly: benefits and risks.

There is controversy over whether elderly patients benefit from the durability of mechanical valves when balanced against the risk of anticoagulation. From 1976 to 1993, 576 patients 65 years old or older underwent isolated valve replacement with mechanical (n = 250) or bioprosthetic valves (n = 326). Total follow-up was 2,222 patient-years. Probability of survival and freedom from thromboembolism and prosthetic valve endocarditis were not different between the two groups. There was a significant difference (p = 0.015) in freedom from anticoagulant-related hemorrhage. Two patients with mechanical prostheses and 7 patients with bioprostheses were reoperated. However, actuarial freedom from reoperation was not different (p = 0.73) in both groups, with no hospital mortality, whereas mortality from thromboembolic events and anticoagulant-related hemorrhage was three times higher in patients with mechanical prostheses as compared with patients with bioprostheses (1.08% versus 0.36% per patient-year). The benefit from the durability of mechanical valves, compared with bioprostheses, is smaller than expected because of the limited number of patients exposed to the onset of bioprosthetic structural deterioration. Elderly patients without absolute indication for anticoagulation should preferentially receive bioprostheses for valvular replacement.

Combined membranous obstruction and saccular aneurysm of the inferior vena cava.

The authors report the history of a 35-year-old man who was operated on because of an asymptomatic combined membranous obstruction and saccular aneurysm of the inferior vena cava (IVC) at diaphragmatic level. Using extracorporeal circulation as well as hypothermia, aneurysm and IVC obstruction were resected and the IVC reconstructed using pericardium. This case and the experience reported in the literature is discussed.

Seal-less centrifugal blood pump with magnetically suspended rotor: rot-a-flot.

Limitations of current centrifugal blood pumps are related to heat generation of bearings and leakage of seals, to dead water zones, and to poor efficiency. A new concept is proposed in this paper to ameliorate these problems based on a miniaturized magnetic drive, and a prototype is introduced. The pump rotor is suspended and driven by a radial permanent magnetic field that stabilizes the impeller in 4 of the 6 spatial degrees of freedom and allows it to be top-spun on a single blood-flushed pivot bearing with minimal load and friction. A shrouded impeller with an open center and 4 logarithmically curved channels is run inside a cone-and-plate-type housing with a spiral volute chamber. In vitro testing was performed comparing this design with the BioMedicus, St. Jude, and Sarns pumps. The prototype is demonstrated to have the smallest internal volume (35 ml), surface (190 qcm), and passage time (0.5 s at 4 L/min), as well as the highest hydraulic efficiency (up to 0.4) of all devices studied.

Sternal closure with resorbable synthetic suture material in children.

The use of resorbable sutures for sternal closure after median sternotomy in children has developed to a clinically routine procedure. Since there is no follow-up study so far about the influence of these synthetic sutures on sternal stability, wound healing, and compatibility in children, we evaluated the use of polydioxanon (PDS) cord in children particularly regarding those properties. In 59 children (weighing up to 30 kg) we could show that the use of synthetic resorbable materials (Vicryl 4/0, PDS) allows a complication-free stability of the sternum, good wound healing, and very good compatibility. It is concluded that the use of PDS cord is a suitable and reliable method for sternal closure with good clinical results.

Bi-ventricular function assessed intraoperatively before and after anatomical correction of transposition of the great arteries.

After anatomical correction of transposition of the great arteries (TGA), the left ventricle (LV) is forced to develop systemic pressures without having had time for adaptation. Thus, one might expect dilatation of the LV at least in the very early intraoperative period following the operation. In nine patients with TGA aged 8-24 days (median 9.5 days) which were selected for arterial switch operation (ASO), Dacron-patch mounted thin piezoceramic transducers were attached intraoperatively by fibrin glue to opposite epicardial surfaces of the right (RV) and/or LV for continuous assessment of external minor diameters (RVD, LVD; sonomicrometry) before and after correction. Right and left ventricular pressures (RVP, LVP) were measured simultaneously and pressure-diameter loops were generated. Right and left ventricular power indices (RVPi, LVPi: = HRxVPxVsD) was calculated from heart rate, ventricular pressures, and systolic shortening of the respective ventricular diameter (RVsD, LVsD). Data obtained during circulatory steady-state immediately before extra-corporeal circulation (ECC) and up to 45 min after ECC were compared. By avoiding volume overload (CVP < or = 10 mmHg) at weaning off ECC and by lowering the systemic vascular resistance and, thus, LV afterload (approximately 8 micrograms.kg-1 min-1 dobutamine), the LV developed systemic pressure (70 +/- 7 vs. 41 +/- 4 mmHg) at unchanged diastolic LV end-diastolic pressure (LVedP) (10 +/- 3 mmHg). Left ventricular power index increased by 45 +/- 25%, although the extent of systolic shortening of LVD was reduced by 20 +/- 10%. Simultaneously, the RV was effectively unloaded (RVedP: 8 +/- 3 vs 11 +/- 6 mmHg; RVP: 39 +/- 7 vs 53 +/- 9 mmHg; RVPi: -42 +/- 27%).(ABSTRACT TRUNCATED AT 250 WORDS)

Importance of the left ventricular subvalvular apparatus for cardiac performance.

The importance of the subvalvular mitral apparatus for left ventricular performance was studied in eight anesthetized dogs. During extracorporeal circulation St. Jude Medical mitral valve prostheses were implanted preserving the chordae tendineae. Flexible wires were slung around the chordae tendineae and brought to the outside through the left ventricular wall to cut the chordae tendineae by electrocautery in the closed beating heart. The left ventricular diameters were measured by sonomicrometry, left ventricular stroke volume and enddiastolic volume by dye dilution, and left ventricular pressure by catheter tip manometer. Data were collected at different preloads achieved by volume loading with blood before and after the chordae tendineae were cut. The results showed that after the chordae tendineae had been cut left ventricular systolic pressure, heart rate, diastolic and systolic diameters of the left ventricle along the minor axis were not different from the pre-cut values at any left ventricular enddiastolic pressure. However, significant differences were observed for maximum dp/dt (-15%), major axis diastolic diameter (+10%) and systolic shortening (-40%), enddiastolic volume (+18%) at any left ventricular enddiastolic pressure, and stroke volume (-24%) at any enddiastolic volume level. The data demonstrate that the subvalvular apparatus not only maintains physiologic valve function, but contributes significantly to left ventricular performance. The impairment of left ventricular function following removal of the subvalvular apparatus might be aggravated in pre-injured hearts in mitral valve disease. Consequently, the subvalvular apparatus should be preserved in mitral valve replacement whenever possible.

Left ventricular function assessed with echocardiography and myocardial perfusion assessed with scintigraphy under dipyridamole stress in pediatric patients after repair for anomalous origin of the left coronary artery from the pulmonary artery.

Twenty-three patients who underwent operation for anomalous origin of the left coronary artery from the pulmonary artery were reexamined with two-dimensional echocardiography and thallium 201 perfusion imaging. Follow-up studies were performed 0.6 to 16.2 years (median 2.9 years) after operation. In 22 of 23 patients, a two coronary artery system had been established by implantation of the left coronary artery into the aorta (n = 8) or by anastomosis of the left subclavian artery with the left coronary artery (n = 14). The left coronary artery had been ligated in only one patient. For stress testing, 0.8 mg dipyridamole per kilogram body weight was infused in a 10-minute period in 20 of the 23 patients. High-dose dipyridamole infusion increased mean heart rate (98.1 +/- 27.1 to 122.3 +/- 19.2 beats/min, p < 0.001) and mean left ventricular ejection fraction (54.8% +/- 11.8% to 61.3% +/- 12.5%, p < 0.05) and decreased left ventricular end-diastolic volume index (38.8 +/- 26.7 to 29.9 +/- 8.3 ml/m2, p < 0.005). At rest, left ventricular dimensions were abnormal in only one patient, in whom the anastomosis with the left coronary artery proved to be occluded, as seen with subsequent angiography. Left ventricular function seen with two-dimensional echocardiography was normal in 19 patients and was compromised in 3 (all of whom had major structural anomalies of the left ventricle, such as left ventricular aneurysm, occlusion of the anastomosis, or mitral valve prosthesis). Patients with R-wave loss as seen with preoperative electrocardiography tended to have larger left ventricular volumes at follow-up (69.2 +/- 56.5 ml/m2 versus 32.4 +/- 9.6 ml/m2, p < 0.07). Ten of 20 patients had normal thallium 201-perfusion scans. In 9 of 20 patients defects revealed by permanent thallium 201-perfusion were observed and determined to be myocardial scars. Transient perfusion defects under dipyridamole stress with redistribution at rest occurred in three children, two of whom also had permanent thallium 201 defects. None of the three patients had angina-like symptoms or S-T segment changes during dipyridamole stress. Left ventricular ejection fraction, however, decreased severely during dipyridamole infusion in the single patient with ligature of the left coronary artery. The two remaining patients had normal echocardiographic left ventricular function under stress, and the diagnosis of myocardial ischemia as seen with scintigraphy must be questioned.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of myocardial ischemia on stimulation-evoked noradrenaline release. Modulated neurotransmission in rat, guinea pig, and human cardiac tissue.

The effect of myocardial ischemia and its major metabolic changes, such as anoxia, acidosis, and hyperkalemia, on exocytotic noradrenaline release was investigated in rat, guinea pig, and human cardiac tissue. Noradrenaline release was evoked by electrical field stimulation, and the effect of each experimental intervention on stimulation-evoked noradrenaline release (S2) was intraindividually compared with the release induced by a control stimulation (S1). In perfused hearts, 10 minutes of global ischemia caused a reduction of noradrenaline overflow in rat hearts (mean S2/S1, 0.31), whereas the overflow was increased in guinea pig hearts (S2/S1, 1.89). This species-dependent effect may be caused by quantitatively different responses to facilitating and suppressing factors of noradrenaline release in both species. Anoxia and substrate-free perfusion increased noradrenaline overflow in guinea pig hearts (S2/S1, 2.40) but had no significant effect in rat hearts (S2/S1, 0.75). Acidosis (pH 6.0) resulted in a suppression of noradrenaline release in rat hearts (S2/S1, 0.16), whereas it had only a minor inhibiting effect in guinea pig hearts (S2/S1, 0.67). Hyperkalemia had a comparable effect in both species (S2/S1 at 15 mmol/L K+, 1.17 in rat and 1.14 in guinea pig; and S2/S1 at 20 mmol/L K+, 0.64 in rat and 0.41 in guinea pig). To obtain results regarding the modulation of noradrenaline release in human myocardium, human atrial tissue was incubated, and the effect of anoxia, acidosis, and hyperkalemia on stimulation-evoked noradrenaline release was investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgery for tricuspid insufficiency: long-term follow-up after De Vega annuloplasty.

Between 1975 and 1991, 97 consecutive patients underwent De Vega tricuspid annuloplasty either isolated or in combination with mitral, aortic, or mitral and aortic valve procedures. Preoperatively 96.9% of the patients were in New York Heart Association functional class III or IV. Causes of tricuspid insufficiency were functional tricuspid ring dilatation and a combination of dilatation and different organic tricuspid valve lesions. There were 17 early deaths (17.5%), primarily due to cardiac failure, none was related to the tricuspid annuloplasty. 80 perioperative survivors have been followed up for a mean of 4.7 +/- 4.1 years with a total of 462 cumulative patient-years. Actuarial 5-, 10-, and 15-year survival rates, including early deaths, were 64% +/- 5%, 48 +/- 6%, and 26% +/- 10%. Recurrence of tricuspid regurgitation was rated as moderate in 15% and severe in 18.8%. Ten patients required reoperation (2.2%/patient-year), of whom 8 were associated with tricuspid regurgitation (1.7%/patient-year). Although in all patients but one the De Vega annuloplasty was intact, the tricuspid ring was dilated; 4 patients had additional tricuspid organic valve lesions. 6 of the 8 patients had concomitant mitral valve or mitral prosthesis dysfunction. 26 patients died late (5.6%/patient-year) due to chronic cardiac failure in 50% and after reoperation in 7% of the patients. 4 patients had implantation of a permanent pacemaker (0.9%/patient-year). 54 patients (67.5%) are still alive, with 43% having no and 17.5% having only mild residual tricuspid regurgitation. De Vega annuloplasty is indicated with tricuspid insufficiency due to functional ring dilatation.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk factors for perioperative mortality in children with anomalous origin of the left coronary artery from the pulmonary artery.

The present study was conducted on 33 children (median age at initial cardiac catheterization 0.4 years [0.1 to 11.8]) with anomalous origin of the left coronary artery from the pulmonary artery, without associated hemodynamically significant cardiovascular anomalies, who were treated throughout a period of 18 years in our hospital. A two coronary artery circulation was reestablished in 31 of 33 children. One child died before the intended operation, and in one child the left coronary artery was ligated. There were six operative deaths, five intraoperative and one 12 hours after operation. The purpose of the study was to assess which preoperative clinical and angiographic features were associated with a higher perioperative mortality. The following preoperative factors were associated with a statistically significant higher perioperative mortality: young age at operation (p less than 0.03), left and balanced type of coronary circulation (p less than 0.01), and electrocardiographic signs of extensive acute myocardial infarction, namely, marked ST elevation (greater than or equal to 0.2 mV in at least two leads) (p less than 0.03). Left axis deviation on the electrocardiogram was associated with an extreme right dominant type of coronary circulation (p less than 0.005). The latter was also linked with adequate perfusion of the posterolateral left ventricular wall (p less than 0.005). At autopsy, severe increase of heart weight to two or three times the normal heart weight was established in six of seven children. Thus the perioperative mortality was determined primarily by the extent of myocardial ischemia. This in turn is decisively influenced by the dominant type of coronary circulation and the extent of inter-arterial collateralization. Young age, in addition, proved to be a risk factor for mortality at corrective surgery.

The influence of pulmonary artery banding on outcome after the Fontan operation.

Thirty-eight patients were selected from a total of 120 patients who underwent the Fontan operation between 1974 and 1988. They were classified into two groups. Group 1 consisted of 18 patients with previous pulmonary artery banding at a mean age of 7 months (2 days to 59 months), and group 2 comprised 20 patients with native pulmonary stenosis. In group 1, 10 children had tricuspid atresia (seven with normally connected and three with transposed great arteries), six had double-inlet ventricle, and two had complex heart malformations. Group 2 consisted of 12 patients with tricuspid atresia and normally connected great arteries, six with double-inlet ventricle, and two with complex malformations. The following clinical and hemodynamic parameters at cardiac catheterization and cineangiocardiography were determined in both groups before the Fontan operation: age and body surface area, hemoglobin concentration and hematocrit value, atrial and pulmonary artery pressures, end-diastolic pressure of the systemic ventricle, arterial oxygen saturation, pulmonary/systemic flow ratio, end-diastolic volume, ejection fraction and mass of the systemic ventricle, cardiac index, and Nakata index. After the Fontan operation in all patients, the presence or absence of pericardial and pleural effusions, ascites, protein-losing enteropathy, and liver and kidney dysfunction was assessed and the clinical status was classified according to New York Heart Association criteria. All preoperative and postoperative parameters were tested for differences between the two groups, and they were compared with normal values. Hematocrit value was higher in group 2 than in group 1 (57.8% versus 53.1%; p less than 0.05). Ventricular mass index was increased in group 1 when compared with group 2 (125.8 gm/m2 versus 87 gm/m2; p less than 0.05). Severe pericardial effusions in the early postoperative period were significantly more frequent in group 1 and were particularly prevalent in the subgroup with long-standing pulmonary artery banding (p less than 0.01). Subaortic stenosis was observed more frequently in group 1. The remaining parameters were not statistically different between the two groups. We conclude that the significant increment in ventricular mass after pulmonary artery banding may represent a risk for unfavorable outcome after the Fontan operation, which increases with time. Therefore, long-standing pulmonary artery banding as a palliative procedure for candidates for the Fontan operation should be avoided.

Influence of age at time of surgery on pre-operative left ventricular mass and postoperative outcome of Fontan operation in children with tricuspid atresia and native pulmonary stenosis.

Purpose of this study was to examine the influence of early (less than two and half years) versus later (greater than four years) age at time of Fontan type palliation in tricuspid atresia with native pulmonary stenosis on outcome with special reference to left ventricular mass and function. Among the 21 patients with tricuspid atresia, twelve (group A) underwent a Fontan type palliation at a median age of one (.6 to 2.5) years and nine (group B) at a median age of 7.5 (4.8 to 28) years. Left ventricular mass was assessed by cross-sectional echocardiography in the apical two and four chamber view. Mass was calculated as difference between epicardial and endocardial volume x 1.05 (specific gravity of heart muscle). Mass divided by volume at end-diastole yielded the mass/volume index. There was a weak correlation between age and left ventricular mass with an r-value of 0.74. Ejection fraction was calculated from the endocardial volume measurements at end-diastole and end-systole. Patient data were compared to normal values previously established in 95 controls, who were age-matched for the patients. Immediately before surgery left ventricular mass was significantly higher in the nine patients, who underwent surgery at a later age. While postoperative stay in hospital and duration of treatment in the intensive care unit did not differ significantly between both groups, the incidence of pleural and pericardial effusions and the duration of insertion of drainage tubes for these effusions differed significantly with the group A patients (under two and half years of age) doing better.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical evaluation of the modified Fontan procedure.

From 1980 to 1990 152 patients underwent Fontan operation at our institution. The following patient groups were identified: 1. patients with tricuspid atresia (n = 82, 54.0%); 2. patients with single ventricle (n = 31, 20.3%); 3. patients with a wide variety of non correctable, complex cardiac malformations (n = 39, 25.7%). In 27.0% of the patients a primary Fontan operation was performed. 45.0% of the patients received a previous shunt to increase pulmonary blood flow and in 29.4% of the patients a pulmonary artery band was placed to reduce pulmonary flow. Overall mortality was not significantly different in patients with previous palliative procedures (19.4%, n = 18) as compared to 17.4% (n = 6) in patients with primary Fontan operation. Risk of death was high in the group with complex cardiac malformations (28.2%, n = 11) and in patients with single ventricle (19.4%, n = 6). Early mortality was considerably less in patients tricuspid atresia (8.5%, n = 7). Postoperatively patients with incorporation of the residual right ventricular chamber and pulmonary valve (Fontan-Bjoerk) showed a significant (p less than 0.05) lower incidence of pleural effusion as compared to patients with other modifications of the Fontan procedure. Actuarial survival rate of all patients is 83.8 +/- 3.1% (mean +/- SEM) at ten years. The modified Fontan procedures are providing an accepted surgical method for patients with otherwise non correctable cardiac malformations.

[Long-term results of Mustard operation in transposition of the great arteries. Angiographic and nuclear medicine study of ventricular function]. / Langzeitergebnisse nach Mustard-Operation bei Transposition der grossen Arterien. Angiographische und nuklearmedizinische Untersuchung der Ventrikelfunktion.

The fate of the right ventricle as systemic ventricle after atrial repair of complete transposition of the great arteries has not been clearly elucidated. In order to assess the long-term results of the Mustard operation in patients with complete transposition of the great arteries we present the clinical data of 23 patients who had been operated in the years 1974 and 1975. Twenty of these patients had simple complete transposition of the great arteries with intact ventricular septum, two had an additional small ventricular septal defect and one an additional left ventricular outflow tract obstruction with a 40 mm Hg systolic pressure gradient. The Mustard operation had been performed at a mean age of 2.2 (1 to 3.7) years. Seventeen of the 23 patients underwent a postoperative hemodynamic study with angiocardiography 1.1 (1 to 1.8) years following surgery. At that time the right ventricular ejection fraction, which had been calculated from biplane angiographic right ventricular volume measurements in twelve patients was 62 (52 to 68) %. However the right ventricle was dilated and the mean enddiastolic volume was 132 (108 to 192) % of normal. In twelve of the 23 patients right ventricular function was reassessed 12.6 (11 to 15.3) years after surgery by Technetium-99m-scintigraphy at rest and in ten of those after exercise with a workload of 2 watt/kg. The mean ejection fraction was 51 (38 to 66) % at rest and 52 (40 to 80) % during exercise. Only three patients had a normal response to exercise, which was defined as an increase of ejection fraction with exercise of more than 5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Importance of the mitral apparatus for left ventricular function: an experimental approach.

In an experimental study of 31 anesthetized dogs the importance of the mitral apparatus for the left ventricular function was investigated. During extracorporeal circulation bileaflet mitral valve prostheses were implanted preserving the mitral subvalvular apparatus. Flexible wires were slung around the chordae tendineae and exteriorized through the left ventricular wall to cut the chordae by electrocautery from the outside when the heart was beating again. External and internal left ventricular dimensions were measured by sonomicrometry, left ventricular stroke volume by electromagnetic flowmeters around the ascending aorta, left ventricular end-diastolic volume by dye dilution technique, and left ventricular pressure by catheter tip manometers. Different preload levels were achieved by volume loading with blood transfusion before and after cutting the chordae tendineae. When the chordae had been divided peak systolic left ventricular pressure did not change. Heart rate only increased at the lowest left ventricular end-diastolic pressures of 3-4 mmHg, but remained unchanged at higher preload levels. Cardiac output decreased significantly up to -9% at left ventricular end-diastolic pressures of 5-10 mmHg, while left ventricular dp/dtmax showed a consistent reduction of up to -15% at any preload level. Significant reductions were also seen in systolic shortening in the left ventricular major axis (by external measurements -27%, by internal recording -43%). Left ventricular end-diastolic dimensions increased in the major axis by +2% when recorded externally, by +10% when measured internally. Systolic and diastolic changes in the minor axis were not consistent and different in the external and internal recordings.(ABSTRACT TRUNCATED AT 250 WORDS)

[Reconstruction of atrioventricular valves in partial and total atrioventricular canal]. / Rekonstruktion der AV-Klappen beim partiellen und totalen AV-Kanal.

Among the anomalies of endocardial cushion defects, the partial (PCAVC) and common (CCAVC) AV canal present a special challenge to the cardiac surgeon. In particular, reconstruction of the AV valve can be difficult in CCAVC because of morphologic variations. Within 17 years, 383 patients with this disease were operated on. Early mortality of PCAVC is below 1%, and of CCAVC below 5%. A total of 90% of the survivors are in NYHA class I. In general, plastic reconstruction of the mitral valve is performed. The risk of reoperation for recurrent mitral incompetence in both groups is between 7% and 10%. Mitral valve replacement is a rare event (1.5%).