The failing Fontan circulation: successful conversion of atriopulmonary connections

OBJECTIVES

Symptoms from low cardiac output or refractory atrial arrhythmias are complicating atriopulmonary (classical) Fontan connections. We present our experience of converting such patients to total cavopulmonary connections with and without arrhythmia surgery.

METHODS

Between 1997 and 2002, 15 patients (mean age, 19.7 +/- 7.0 years) underwent conversion operations 12.7 +/- 3.5 years after atriopulmonary Fontan operations. Preoperative New York Heart Association functional class was I in 2 patients, II in 2 patients, III in 6 patients, and IV in 5 patients. Four patients underwent intracardiac lateral tunnel conversion alone, and 11 received extracardiac total cavopulmonary connection, right atrial reduction, and cryoablation.

RESULTS

No mortality occurred. One patient had conduit obstruction in the immediate postoperative period requiring replacement, and another required a redo operation for endocarditis. Average hospitalization was 17.9 +/- 9.38 days; chest drains were removed on median day 4 (range, 1-29; mean, 7.4 +/- 7.58 days). At follow-up (mean, 42.6 +/- 22.1 months), late atrial arrhythmias had recurred in 3 of 4 patients with intracardiac total cavopulmonary connections (without ablation) and 1 of 11 patients with extracardiac total cavopulmonary connections with ablation. All patients are in New York Heart Association class I or II. Exercise ability (Bruce protocol) improved 69% from a mean of 6.18 +/- 4.01 minutes to 10.45 +/- 2.11 minutes (P <.05). Need for antiarrhythmic agents decreased postoperatively (patients receiving < or =1 antiarrhythmic: 9 preoperatively vs 15 at long-term follow-up, P <.05). No patient has required transplantation. Protein-losing enteropathy, which was present in 1 patient, improved transiently with conversion. There was 1 late death from gastrointestinal hemorrhage.

CONCLUSIONS

Fontan conversion can be achieved with low mortality and improvement in New York Heart Association class and exercise ability. Concomitant arrhythmia surgery reduces the incidence of late arrhythmias.

Aortic root replacement in patients with Marfan's syndrome: the Southampton experience

BACKGROUND

The purpose of this study was to evaluate the early and late clinical outcome after aortic root replacement (ARR) in patients with Marfan's syndrome.

METHODS

A total of 65 consecutive patients with Marfan's syndrome (mean age 41.7 +/- 10.7 years, range 15 to 76 years) undergoing ARR between 1972 and 1998 in Southampton were studied. Of the patients, 45 had a chronic aneurysm of the ascending aorta and 20 had a type A dissection (16 acute and 4 chronic). The operations were elective in 38 and nonelective in 27 cases (emergency in 22 and urgent in 5). Mean size of the ascending aorta was 6.3 +/- 1.4 cm (3.8 to 12 cm). A Bentall procedure was performed in 62 and a homograft root replacement in 3 patients. Mean follow-up was 8 +/- 4.1 years (0 to 22.9 years).

RESULTS

Operative mortality was 6.1% (4 deaths) (for the elective vs nonelective procedures it was 2.6% vs 11%, p = 0.2). The 10-year freedom from thromboembolism, hemorrhage, and endocarditis was 88%, 89.8%, and 98.4% (0.9%, 0.9%, and 0.2% per patient-year) and from late aortic events it was 86.3% (1.3% per patient-year). Aortic root replacement for dissection was an independent predictor of occurrence of late aortic events (p = 0.01). Five patients had a reoperation with one early death. The 10-year freedom from reoperation was 89.2% (1.1% per patient year) (for elective and nonelective procedures, 90.8% vs 84.6%, p = 0.6). The 10-year survival, including operative mortality, was 72.7% (for elective and nonelective procedures, 78% vs 66.5%, p = 0.6). Late aortic events was an independent adverse predictor of survival (p = 0.02).

CONCLUSIONS

In patients with Marfan's syndrome, elective ARR, usually for chronic aneurysm, is associated with a low mortality, low rate of aortic complications, and good late survival. Nonelective ARR, mostly for dissection, has a greater operative risk and a significantly higher incidence of late catastrophic aortic events. Early prophylactic surgery in these patients is therefore recommended. Long-term clinical and radiologic follow-up to prevent or to treat late aortic events is highly desirable.

Is there still a place for open surgical valvotomy in the management of aortic stenosis in children? The view from Southampton

OBJECTIVE

The most appropriate management of aortic stenosis (AS) in children remains controversial. The purpose of this study was to determine the outcome following open valvotomy for AS in children.

METHODS

Ninety-seven consecutive, unselected, children (mean age 3.2 +/- 3.6 years, 1 day--15 years) underwent an open valvotomy for critical (n=36) or severe (n=61) AS between 1979 and 2000 in Southampton. Twenty-six were neonates (1--31 days), 27 were infants (1--12 months) and 44 were older children (1--15 years). Mean follow-up was 10 +/- 5.4 years, 1 month--21.9 years.

RESULTS

Two neonates died early giving an overall operative mortality of 2.1% (7.7% for the neonates and 0% for infants and older children). The mean aortic gradient was reduced from 76 to 24.5 mmHg (P < 0.0001). Residual or recurrent AS occurred in 17 patients and severe aortic regurgitation in eight patients. Kaplan--Meier 10-year freedom from residual or recurrent AS was 83.1 +/- 4.7% and from severe aortic regurgitation was 95.3 +/- 2.7%. Twenty-five patients required an aortic re-operation or re-intervention, 18 of whom had an aortic valve replacement (AVR) (mean valve size 21.8 +/- 0.9 mm, range 21--25 mm). Ten-year freedom from any aortic re-operation or re-intervention was 78.4 +/- 5.2% and from AVR was 85.1 +/- 4.6%. There were ten late deaths. Overall 10-year survival, including hospital mortality, was 90.2 +/- 3.1% (69.7 +/- 9.7% for the neonates, 92 +/- 5.4% for the infants and 100% for older children, (P < 0.0001). Ten-year survival for children with isolated AS (n = 69) was 100% and for those with associated cardiovascular problems (n = 28) was 67.3 +/- 8.9% (P < 0.0001). All survivors are in New York Heart Association functional class I.

CONCLUSIONS

Open valvotomy remains the gold standard in the management of AS in neonates, infants and older children. It is associated with low operative mortality and provides lengthy freedom from recurrent AS and regurgitation. Re-operations are common but if AVR is required, implantation of an adult-sized prosthesis is usually possible. There is a late death-hazard for those with severe associated lesions, but the survival prospects for the patients with isolated AS are excellent.

Mitral valve replacement with mechanical prostheses in children: improved operative risk and survival

OBJECTIVE

The purpose of this study was to assess the early and late outcome following mitral valve replacement (MVR) with mechanical prostheses in children.

PATIENTS AND METHODS

Between 1981 and 2000, 44 consecutive children (mean age 6.8+/-4.7 years, 2 months--16 years) underwent mechanical MVR in Southampton. Twenty-three children were less than 5-years-old and nine were infants. Disease aetiology was congenital in 37, rheumatic in four, infective in two and Marfan's syndrome in one. Mitral regurgitation was present in 36 and mitral stenosis in eight. Concomitant procedures were performed in 13, including aortic valve replacement (AVR) in seven. Follow-up was complete (mean 6.4+/-4.8 years, 1 month--18.1 years).

RESULTS

The overall operative mortality was 14% (six patients). Before and after 1990 operative mortality was 31 vs 3.6% (P=0.02). From 1990, operative mortality for infants was zero out of six, for children less than 5-years-old was one out of 16 (one death after emergency AVR and MVR) and for older children it was 0/12. Seven children experienced valve or anticoagulation treatment-related events and eight had a mitral valve re-operation. Ten-year freedom from thromboembolism, prosthetic valve infection, bleeding, paravalvular leak and a mitral valve re-operation was 92.8+/-5.2, 97.3+/-2.7, 97.7+/-2.3, 97.2+/-2.7 and 75+/-9.7%, respectively. Overall 10-year survival was 78+/-7% (four late deaths); for children under vs over 5 years it was 61+/-11 vs 95.2+/-4.6% (P=0.02), for atrio-ventricular septal defect (AVSD) vs other pathology 55+/-15 vs 89+/-6.1% (P=0.05) and for those operated before 1990 vs after 1990 it was 63+/-8.1 vs 86+/-8.2% (P=0.04).

CONCLUSIONS

Mechanical MVR, in the current era, carries a low operative risk across the spectrum of paediatric age. Late survival is better for older children and those having no-AVSD pathology but it has improved substantially during the 1990s irrespective of age and disease aetiology.

Assessment of mortality rates for congenital heart defects and surgeons' performance

BACKGROUND

In the absence of reliable national data, we have collected results of all operations for congenital heart defects from five departments to assess mortality rates and compare them among surgeons and departments.

METHODS

Data relating to all operations (2,718) carried out at the five centers during a period from April 1, 1997 through March 31, 1999. Clearly defined criteria were agreed for the classification of patients into various subgroups.

RESULTS

The overall hospital mortality was 4.4% (95% confidence intervals 3.7%-5.3%). Mortality for open-operations was 12.6% in neonates, 5.1% in infants, and 3.5% in children. Mortality rates were 1.1% for coarctation, 0.4% ventricular septal defect, 4.1% atrioventricular septal defect, 2.9% Fallot, 0.9% switch, and 15.6% truncus arteriosus. Although individual surgeons' mortality rates ranged from 1.8% to 7.5%, none of the 12 surgeons' data were above 95% confidence intervals. For individual surgeons, the change in mortality rates between the 2 years ranged between -3.3% and +3.8%.

CONCLUSIONS

With 2 years' data available, estimates of mortality rates are more precise as reflected by tighter confidence intervals. There were relatively small data sets for individual hospitals and surgeons, which made statistical evaluation difficult. For setting standards, data from more departments for a longer period will be required. Statistical methods alone cannot be used as a sole arbiter of what is considered acceptable performance.

Repair of truncus arteriosus in early infancy with antibiotic sterilized aortic homografts

BACKGROUND

To evaluate the fate of the truncal valve, the antibiotic sterilized aortic homografts, and the survival after repair of truncus arteriosus in the first 6 months of life.

METHODS

Between 1974 and 1994, 23 infants (mean age 1.7 months, range 5 days to 6 months) underwent primary repair of truncus arteriosus by one surgeon (J.L.M). Sixteen were neonates (age range 5 to 30 days). Continuity between the right ventricle and the pulmonary artery was established with an aortic antibiotic sterilized homograft (mean diameter 14.9 mm, range 11 to 17 mm). Follow-up was 100% complete.

RESULTS

Four neonates with severe truncal regurgitation died early (17.4%). Fourteen patients underwent reoperations. Five had a truncal valve replacement (mean time 7 years, range 6 months to 17 years). Ten-year freedom from truncal valve replacement was 78.2%. Eleven patients had homograft replacement (mean time 12.7 years, range 2 to 26.2 years). Ten-year freedom from homograft replacement for any cause was 77.1% (for homograft-related problems it was 86.7%). Seven patients retained the original homografts (mean time 14.3 years, range 6 to 18.7 years). There was one late death. Overall 10-year survival was 79% and for the hospital survivors it was 95%. All survivors are in New York Heart Association functional class I.

CONCLUSIONS

Abnormal truncal valves pose serious early and late problems but the patients with normal truncal valves do well and seem unlikely to need replacement of these valves. The durability of the antibiotic sterilized aortic homograft even in sizes less than 14 mm is remarkably good. Late survival is excellent.

Autotransfusion decreases blood usage following cardiac surgery -- a prospective randomized trial

INTRODUCTION

10% of blood issued by the National Blood Service (220,000) is utilised in cardiac procedures. Transfusion reactions, infection risk and cost should stimulate us to decrease this transfusion rate. We tested the efficacy of autotransfusion of washed postoperative mediastinal fluid in a prospective randomized trial.

PATIENTS AND METHODS

166 patients undergoing coronary artery bypass grafting (CABG), valve or CABG + valve procedures were randomized into three groups. The indication for transfusion was a postoperative haemoglobin (Hb) < 10 g/l or a packed cell volume (PCV) < 30. When applicable, group A patients received washed post-operative drainage fluid. Group B all received blood processed from the cardiopulmonary bypass (CPB) circuit following separation from CPB and if appropriate washed post-operative drainage fluid. Group C were controls. Groups were compared using analysis of variance.

RESULTS

There was no significant difference in age, sex, type of operation, CPB time and preoperative Hb and PCV between the groups. Blood requirements were as shown. [table - see text] Twelve patients in group A and 10 in group B did not require a homologous transfusion following processing of the mediastinal drainage fluid.

CONCLUSION

Autotransfusion of washed postoperative mediastinal fluid can decrease the amount of homologous blood transfused following cardiac surgery. There was no demonstrable benefit in processing blood from the CPB circuit as well as mediastinal drainage fluid.

Division of modified Blalock-Taussig shunt at correction avoids distortion of the pulmonary artery

BACKGROUND

Modified Blalock-Taussig (BT) shunt causing pulmonary artery distortion has been reported. This distortion may get worse after a corrective operation if the BT shunt is ligated, rather than divided. In this study we examined whether division of modified BT shunt at the time of corrective operation would allow pulmonary artery growth and avoid further distortion.

METHODS

Fifteen patients who had modified BT shunts and subsequently had corrective operations performed by one surgeon between January 1980 to December 1990 were analyzed. The median time from the BT shunt to corrective operation was 46.3 months (range, 3 to 119 months). At the time of corrective procedure, the BT shunt was divided and metal clips were used to occlude and mark each end. At follow-up a chest roentgenogram was obtained and the distance between the two clips was measured.

RESULTS

In all 15 patients measured sequentially the distances between the two clips increased steadily.

CONCLUSIONS

Division of BT shunt at the time of corrective procedure reduces pulmonary artery distortion.

Outcome after repair of tetralogy of Fallot in the first year of life

BACKGROUND

The purpose of this study was to evaluate the early and late outcome after repair of tetralogy of Fallot in the first year of life.

METHODS

Between 1974 and 2000, 89 consecutive infants with a mean age of 6.3 +/- 2.6 months (range, 15 days to 12 months) underwent repair of tetralogy of Fallot (ventricular septal defect and pulmonary stenosis) by one surgeon (J.L.M.). Three infants had previous palliative operations. Sixty-seven procedures were urgent or emergency. A transannular patch was inserted in 69 patients (77.5%). Follow-up was complete, averaging 13.4 +/- 5.6 years (range, 0 to 25.4 years).

RESULTS

There was one operative death (1.1%). Mean right ventricular to left ventricular pressure ratio postoperatively was 0.4 +/- 1.1 (in 79 patients, < 0.5). Fourteen patients underwent reoperations or reinterventions. There were no reoperations for residual or recurrent ventricular septal defect. Kaplan-Meier freedom from reoperation or reintervention for any cause at 20 years was 85% +/- 4.4%, for relief of right ventricular outflow tract obstruction it was 94% +/- 3.1%, and for pulmonary valve replacement this was 95.4% +/- 2.6%. Use of a transannular patch did not significantly affect the need for reoperation or reintervention. There was one late death (leukemia). Kaplan-Meier 20-year survival was 97.8% +/- 1.9%. On latest echocardiography, 42 patients had moderate pulmonary regurgitation, 4 had a right ventricular outflow tract gradient more than 40 mm Hg, and 86 had good biventricular function. Twelve-lead electrocardiography was performed in all and 24-hour electrocardiography in 61 patients. One patient (1.1%) exhibited late recurrent ventricular tachycardia requiring implantation of a defibrillator. The remaining 86 patients are in New York Heart Association class I with none of them receiving antiarrhythmic medications.

CONCLUSIONS

These data strongly support the concept of early repair of tetralogy of Fallot. It is associated with an acceptable operative risk and a low incidence of significant arrhythmias, and provides long-term survival similar to that observed in the general population. Late complications may, however, develop, and long-term follow-up for their early recognition is essential.

Open commissurotomy for critical isolated aortic stenosis in neonates

BACKGROUND

The optimal management of critical aortic stenosis in early infancy remains controversial. The aim of this study was to assess the early and late outcomes following open surgical valvotomy for critical aortic stenosis in neonates and to provide a framework of data against which current results of other treatment approaches can be evaluated.

METHODS

Eighteen consecutive neonates (mean age 9.2 days, range 1 to 26 days) undergoing an open valvotomy for critical isolated aortic stenosis (the standard treatment for this condition in our unit) between 1984 and 2000 were studied. The mean aortic valve gradient was 79.4 mm Hg. Twelve neonates received prostaglandins and 10 received inotropic agents preoperatively. Follow-up was complete (mean 8.1 years, range 1 month to 15 years).

RESULTS

There was no operative mortality. At discharge, the mean aortic valve gradient was 37.2 mm Hg, with 6 patients having mild and 2 having moderate aortic regurgitation. Six patients required a reoperation; 3 of these had an aortic valve replacement at 9 to 11 years of age. Kaplan-Meier 5- and 10-year freedoms from any aortic reoperation or reintervention were 85 and 55%, respectively; 5- and 10-year freedoms from aortic valve replacement were 100 and 79%, respectively. A 14-year-old boy died from endocarditis 4 years following an aortic valve replacement in another unit. Kaplan-Meier 10-year survival was 100%. All survivors are in New York Heart Association I class and are leading normal lives. Their mean aortic valve gradient is 34.5 mm Hg, and none has significant aortic regurgitation.

CONCLUSIONS

Open valvotomy for critical aortic stenosis in neonates carries a low operative risk and provides lengthy freedom from recurrent stenosis or regurgitation. Reoperations are inevitable, but aortic valve replacement can be delayed until the implantation of an adult-sized prosthesis is possible. Late survival is excellent. We consider open surgical valvotomy to be the treatment of choice for critical neonatal aortic stenosis.

Aortic valve replacement for endocarditis: determinants of early and late outcome

BACKGROUND AND AIM OF THE STUDY

The study aim was to determine risk factors for operative mortality, recurrent infection, reoperation and long-term survival following aortic valve replacement (AVR) for infective endocarditis.

METHODS

Between 1973 and 1997, 109 patients (91 male, 18 female, mean age 52.6 years) underwent isolated AVR for infective endocarditis in our unit. Native valve endocarditis was present in 89 (81.6%) and prosthetic valve endocarditis in 20 (18.4%). Active culture-positive endocarditis was present in 53 (48.6%). Preoperatively, 99 patients (90.8%) were in NYHA classes III and IV. Indications for surgery included cardiac failure in 41 patients, valvular dysfunction in 38, vegetations in 18, sepsis in seven, abscess in six and embolism in four. Mechanical valves were implanted in 69 patients (63.3%) and bioprostheses in 40 (36.7%), including a homograft in 19 (17.4%). Follow up was complete (mean 5.8 years; range: 0-23.8 years; total 633.5 patient-years).

RESULTS

The operative mortality was 10.1% (11 deaths). At ten years, freedom from recurrent infection was 94.2%, and freedom from reoperation 83.6%. Biological valve and younger age were significant adverse parameters for freedom from reoperation (p = 0.01 and p = 0.01). There have been 21 late deaths, 15 due to cardiac causes. Kaplan-Meier survival, including operative mortality, at five and ten years was 77.4% and 68.0%, respectively. On Cox proportional hazards regression, Staphylococcus aureus infection (p = 0.008) and older age (p = 0.04) were independent adverse predictors of survival.

CONCLUSION

AVR for endocarditis carries a relatively high operative mortality, but can result in a satisfactory freedom from recurrent infection, reoperation and long-term survival. Analysis of our series demonstrates that implantation of a biological valve limits the freedom from reoperation and that infection by Staph. aureus reduces the probability of long-term survival.

Surgery for active culture-positive endocarditis: determinants of early and late outcome

BACKGROUND

The purpose of this study was to describe a single unit experience in the surgical treatment of active culture-positive endocarditis and identify determinants of early and late outcome.

PATIENTS AND METHODS

One hundred eighteen consecutive patients with positive blood culture up to 3 weeks before operation (or positive valve culture) and macroscopic evidence of lesions typical for endocarditis, undergoing operation between January 1973 and December 1996 in Southampton, were evaluated. The aortic valve was infected in 53 (48.9%), the mitral in 46 (39%), both aortic and mitral in 12 (10.1%), the tricuspid in 4 (3.9%), and the pulmonary valve in 3 (2.5%). Native valve endocarditis was present in 83 (70.3%) and prosthetic valve endocarditis in 35 (29.7%). Streptococci and staphylococci were the most common pathogens. Mean follow-up was 5.6 years (range, 0 to 25 years).

RESULTS

Operative mortality was 7.6% (9 patients). Endocarditis recurred in 8 (6.7%). A reoperation was required in 12 (10.2%). There was 24 late deaths, 17 of them cardiac. Actuarial freedom from recurrent endocarditis, reoperation, late cardiac death, and long-term survival at 10 years were 85.9%, 87.2%, 85.2%, and 73.1%, respectively. On multiple regression analysis the following were independent adverse predictors: pulmonary edema (p = 0.007) and impaired left ventricular function (p = 0.02) for operative mortality; prosthetic valve endocarditis (p = 0.01) for recurrent infection; myocardial invasion by the infection (p = 0.01) and reoperation (p = 0.04) for late cardiac death; and coagulase-negative staphylococcus (p = 0.02), annular abscess (p = 0.02), and longer intensive care unit stay (p = 0.02) for long-term survival.

CONCLUSIONS

Operation for active culture-positive endocarditis carries an acceptable mortality. Freedom from recurrent infection, reoperation, and long-term survival are satisfactory. In our data, patients' hemodynamic status at operation was the major determinant of operative mortality. Prosthetic valve endocarditis, coagulase-negative staphylococcus, and annular or myocardial infectious invasion were the critical adverse determinants of late outcome.

Surgical treatment of infective mitral valve endocarditis: predictors of early and late outcome

BACKGROUND AND AIMS OF THE STUDY

The study aim was to review our experience in surgical treatment of infective mitral valve endocarditis, and to identify predictors of early and late outcome.

METHODS

Ninety-one consecutive patients (52 males, 39 females, mean age 55.6 years) underwent surgery between 1973 and 1997 for endocarditis of isolated mitral (n = 65, 71%), mitral and aortic (n = 25, 28%) and mitral, aortic and tricuspid valves (n = 1, 1%). Native valve endocarditis (NVE) was present in 60 patients (66%) and prosthetic valve endocarditis (PVE) in 31 (34%). The main indications for surgery were heart failure in 32 patients, valve dysfunction in 23, vegetations in 21, and persistent sepsis in 11. Eighty-six patients (95%) were in NYHA classes III-IV, and 58 (64%) had active culture-positive endocarditis at surgery. Mechanical valves were implanted in 73 patients and bioprosthetic valves in 13; valves were repaired in five patients. The impact of 46 parameters on early and late outcome was defined by means of univariate and multivariate statistical analysis. Follow up was complete (mean 5.5 years; range: 0-23.1 years; total 507.3 patient-years).

RESULTS

Operative mortality rate was 11% (n = 10). Recurrent infection was recorded in five patients (6%), and reoperation was required in eight (9%). Freedom from recurrent infection and reoperation at 10 years was 89.1% and 87.8% respectively. There were 22 late deaths, 15 from cardiac causes. Actuarial survival rates for all patients at 5, 10 and 15 years were 73.0%, 62.7% and 58.7% (for hospital survivors, the corresponding rates were 81.9%, 69.7% and 66.0%). On multiple logistic regression and Cox proportional hazards models, the following were independent predictors: preoperative pulmonary edema (p = 0.01) for operative mortality; PVE (p = 0.02) for recurrence; younger age (p = 0.02) and PVE (p = 0.02) for reoperation; male gender (p = 0.004) and longer ITU stay for survival (if all patients were included); male gender (p = 0.01) and myocardial invasion by infection (p = 0.02) for survival (if only the hospital survivors were analyzed).

CONCLUSION

Surgery for infective mitral valve endocarditis carries a relatively high, though acceptable, risk but provides satisfactory freedom from recurrent infection, reoperation and improved long-term survival. Analysis of these data demonstrated that the preoperative hemodynamic status was the major predictor of in-hospital outcome, PVE increased the risk for recurrent infection and reoperation, whereas male gender and myocardial invasion by the infective process critically reduced the probability of long-term survival. The type of offending pathogen, the activity of infection and the involvement of more than one valve did not appear to influence early and/or late outcome.

Mid-term results with 1,503 CarboMedics mechanical valve implants

BACKGROUND AND AIM OF THE STUDY

The CarboMedics bileaflet prosthetic heart valve was introduced in 1986, and first implanted by the authors in March 1991. The aim of this study was to analyze the authors' clinical experience with this valve.

METHODS

Between March 1991 and October 1998, 1,503 valves were implanted in 1,350 patients (758 males, 592 female; mean age 62 +/- 13 years). Follow up was 99% complete and totaled 4,342 patient-years (pt-yr).

RESULTS

The hospital mortality rate was 4.3% (59/1,350). Preoperative NYHA class (p = 0.012), emergency surgery (p = 0.03) and cardiopulmonary bypass time (p = 0.01) were significantly associated with increased risk of operative death (multiple logistic regression). Mean (+/- SEM) survival rates at one and five years were 92.0 +/- 0.7% (n = 1,109) and 80.0 +/- 1.3% (n = 335). Freedom from valve-related complications (linearized rate 5.6%/pt-yr) at one and five years was 89.5 +/- 0.8% (n = 1,031) and 76.3 +/- 1.4% (n = 284). Linearized rates for bleeding events were 2.19%/pt-yr, thromboembolic events 2%/pt-yr, operated valvular endocarditis 0.18%/pt-yr, valve thrombosis 0.14%/pt-yr and non-structural dysfunction 1.22%/pt-yr. Freedom from reoperation at one and five years was 98.5 +/- 0.3% (n = 1,107) and 97.3 +/- 0.5% (n = 334).

CONCLUSION

Mid-term results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.

Intrapulmonary arteriovenous shunting may be a universal phenomenon in patients with the superior cavopulmonary anastomosis: a radionuclide study

OBJECTIVE

To evaluate the extent of intrapulmonary right to left shunting in children after bidirectional cavopulmonary anastomosis (BCPA).

DESIGN

Prospective study of patients who underwent BCPA in a single centre.

PATIENTS

17 patients with complex cyanotic congenital cardiac malformations who underwent BCPA at 1-45 months of age (median 21 months) were evaluated 15-64 months postoperatively (median 32 months). Five children between 1 and 10 years (median 5 years) with normal or surgically corrected intracardiac anatomy and peripheral pulmonary circulation who required V/Q scanning for other reasons were used as controls.

INTERVENTIONS

All patients underwent cardiac catheterisation to exclude angiographically demonstrable venovenous collaterals followed by pulmonary perfusion scanning using (99m)technetium ((99m)Tc) labelled albumen microspheres to quantify the intrapulmonary right to left shunt.

MAIN OUTCOME MEASURE

Percentage of intrapulmonary right to left shunt.

RESULTS

The mean (SD) level of physiological right to left shunting found in the control group was 5.4 (2.3)%. All patients with BCPA showed the presence of a significantly higher level of intrapulmonary shunting (26.8 (16.9)%, p < 0.001). The degree of shunting was significantly increased in the subgroup of 11 patients with BCPA as the only source of pulmonary blood flow (34.9 (15.8)%), when compared to the six remaining patients with an additional source of pulmonary blood supply (12.0 (2.6)%, p < 0.001). There was a negative correlation between age at BCPA and the shunt percentage found in the patients with a competitive source of pulmonary blood flow (r = -0.63, p < 0. 01).

CONCLUSIONS

Intrapulmonary right to left shunting develops in all patients following BCPA. This may be caused by a sustained and inappropriate vasodilatation resulting from absence or decreased levels of a substance that inhibits pulmonary vasodilatation. Augmenting BCPA with an additional source of blood flow containing hepatic factor limits the degree of intrapulmonary arteriovenous shunting and may help provide successful longer term palliation.

Mortality rates after surgery for congenital heart defects in children and surgeons' performance

BACKGROUND

A public inquiry into surgery for paediatric congenital heart defects in Bristol, UK, underscored the need for reliable data on overall mortality rates, which would allow assessment of individual surgeons' performance. We aimed to gather and report such data for 1 year to provide information for clinicians, researchers, policy makers, and the general public.

METHODS

We collected data on all operations (1378) for congenital heart defects done by 11 surgeons in five departments in the UK between April 1, 1997, and March 31, 1998. These operations represented about 36% of all operations done in the UK during that time. Clearly defined criteria were agreed to classify operations into subgroups.

FINDINGS

The overall mortality rate for all operations was 4.0% (95% CI 3.0-5.2). No deaths occurred for 67 arterial-switch operations. Mortality rates for coarctation, ventricular septal defect, atrioventricular septal defect, Fallot, and truncus arteriosus operations were 1.1%, 0.6%, 3.6%, 2.3%, and 28.6%, respectively. Although overall mortality rates between surgeons varied (1.6-6.9%), no surgeon's were higher than the 95% CI. The numbers of operations done by individual surgeons were small, which led to wide confidence intervals and made the detection of differences in performance difficult.

INTERPRETATION

The participating departments seemed to reach high standards of care for children with congenital heart defects, although more data would be needed to assess performance of individual surgeons. The development of quality standards will be difficult because of the complexity of defects, the different types of operations, and few patients in each subgroup. Collection of larger sets of data for more patients and centres are needed.

A single-center experience with 1,378 CarboMedics mechanical valve implants

BACKGROUND

The CarboMedics bileaflet prosthetic heart valve was introduced in 1986. We first implanted it in March 1991. The purpose of this study was to analyze our clinical experience with this valve.

METHODS

Between March 1991 and December 1997, 1,378 valves were implanted in 1,247 patients, 705 men (56.5%) and 542 (43.5%) women with a mean age of 62 +/- 11.9 years (+/- the standard deviation). Follow-up is 99% complete and totals 3,978 patient-years.

RESULTS

The early mortality rate was 4.4% (55/1,247). The survival rates at 1 year and 5 years were 91.8% +/- 0.8% (+/- the standard error of mean) (n = 1,062) and 79.2% +/- 1.4% (n = 281), respectively. Freedom from valve-related complications (linearized rate, 4.9% per patient-year) at 1 year and 5 years was 90.6% +/- 0.8% (+/- the standard error of the mean) (n = 996) and 80.6% +/- 1.4% (n = 243), respectively. Linearized rates for various complications were as follows: bleeding events, 1.73% per patient-year; embolic events, 1.76% per patient-year; operated valvular endocarditis, 0.18% per patient-year; valve thrombosis, 0.10% per patient year; and nonstructural dysfunction, 1.21% per patient-year. Freedom from reoperation at 1 year and 5 years was 98.6% +/- 0.3% (+/- the standard error of the mean) (n = 1,070) and 97.7% +/- 0.5% (n = 285), respectively.

CONCLUSIONS

Midterm results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.

Aortic valve replacement in children: are mechanical prostheses a good option?

OBJECTIVE

The choice of the most appropriate substitute in children with irreparable aortic valve lesions remains controversial. The aim of this study was to assess early and late outcomes following aortic valve replacement (AVR) with mechanical prostheses in children.

PATIENTS

Fifty-six patients (42 male, 14 female, mean age 11.2, range 1-16 years) undergoing AVR with mechanical prostheses between October 1972 and January 1999 were evaluated. Thirty-six patients (64.2%) underwent previous cardiac surgery. Disease aetiology was congenital in 47 patients (congenital aortic stenosis in 33, and other congenital abnormalities in 14) (83.9%), infective in four (7. 1%), rheumatic in two (3.4%), and three (5.3%) had connective tissue disorders. Haemodynamic indication for AVR was aortic regurgitation (AR) in 24 (42.8%), aortic stenosis (AS) in 22 (39.2%) and mixed disease in ten (17.8%). Twenty-eight patients (50.0%) were in New York Heart Association (NYHA) class III-IV before surgery. Concomitant procedures were performed in 31 patients (55.3%), including aortic root enlargement in 28 (50%). The mean size of implanted valves was 22.4 mm (range 17-27 mm). All patients received long-term anticoagulation treatment with sodium warfarin, aiming to maintain an international normalized ratio (INR) between 2.5-3.0. The mean follow-up was 7.3 years (range 0-26, total 405 patient-years).

RESULTS

Operative mortality was 5.3% (three patients). Three patients developed complete heart block requiring pacing, two of them permanently. Late events included valve thrombosis (one), transient stroke (one), paravalvular leak of a mitral prosthesis (one), aneurysm of sinus of Valsalva (one) and pannus ingrowth (one). There was no major haemorrhagic event. Five patients required re-operation (8.9%), but none due to outgrowth of the valve. Regarding actuarial freedom from thrombo-embolism, any valve-related event and re-operation at 20 years was 93, 86.6 and 86. 4%. There were three late deaths. Actuarial survival, including operative mortality, at 10 and 20 years was 91 and 84.9%. The actuarial survival for the group of the patients with congenital AS (n=33) at 10 and 20 years was 93.5%, whereas for the children with other congenital heart problems (n=14) this was 85.7 and 64.3% (P=0. 09). At the latest clinical evaluation, 44 children were in NYHA class I and six were in class II. The mean gradient across the aortic prosthetic valve on echocardiography was 17.9 mmHg (range 0-47 mmHg).

CONCLUSIONS

Mechanical AVR, with enlargement of the aortic root if necessary, remains an excellent treatment option in children. It is associated with acceptable operative mortality, low incidence of late events and re-operation, and provides good long-term survival. It clearly represents a good alternative to available biological substitutes, including the pulmonary autograft (Ross procedure).

The fate of antibiotic sterilized aortic allografts in Fontan circulation: results of the long-term follow-up

OBJECTIVE

Between 1977 and 1988, 27 patients, mean age 8.9 (range 4-22) received an antibiotic sterilised aortic allograft in the setting of the Fontan procedure. This study describes the long-term follow-up of these patients.

METHODS

Fifteen patients had tricuspid atresia, nine double inlet ventricles and three others. The connection with the allograft was made to the pulmonary artery on the right side of the aorta in ten and to a left-sided main pulmonary artery in eight. In nine patients the allograft was anastomosed between the right atrium and the right ventricle.

RESULTS

There were five early and five late deaths. One late death may have been allograft related. Survival was 81, 74 and 68% at 5, 10 and 15 years, respectively. Conduit calcification was universal. Twelve patients underwent reoperation, freedom from reoperation was 100, 88 and 54% at 5, 10 and 15 years following the initial Fontan procedure. At reoperation the gradient across the allograft was never more than 3 mmHg. The allograft was explanted with conversion to atriopulmonary or cavopulmonary connection in nine and a second allograft was inserted between the right atrium and right ventricle in two. No mortality occurred at reoperation. 41.1% of survivors still have their original allograft.

CONCLUSIONS

Although there is a significant attrition rate allograft inclusion in the Fontan circulation does not change survival, but results in an increased reoperation rate. Inclusion of a valved conduit between the right atrium and ventricle does not usually enhance the growth potential of the rudimentary ventricle. All patients are in a good functional class which may represent the strict original selection criteria. The inclusion of a valve in the Fontan circulation is not recommended.

Replacement of the proximal aorta and aortic valve using a composite bileaflet prosthesis and gelatin-impregnated polyester graft (Carbo-Seal): early results in 143 patients

OBJECTIVE

We report the combined early results from two centers in the United Kingdom using a composite conduit consisting of a bileaflet mechanical valve incorporated into a gelatin-impregnated, ultra-low porosity, woven polyester graft (Carbo-Seal; Sulzer Carbomedics, Inc, Austin, Tex).

METHODS

Between August 1992 and March 1997, 143 patients underwent aortic root replacement with the Carbo-Seal composite prosthesis. The indication for surgery was acute type A dissection in 31 (22%), chronic type A dissection in 9 (6%), ascending aortic aneurysm without dissection in 100 (70%), and false aneurysm of the ascending aorta in 3 (2%). Twenty-seven patients (19%) had undergone previous sternotomy, and 40 (28%) were seen as emergencies. Concomitant procedures were performed in 38 (27%), including 18 aortic arch or hemiarch replacements. Total follow-up is 270 patient-years. Follow-up is 100% complete.

RESULTS

The early (30-day) mortality was 7% (10 patients). Permanent neurologic events occurred in 2%. At a mean follow-up of 23 months, 94% of survivors were in New York Heart Association functional class I. Freedom from reoperation was 97.2% +/- 1.6% (1 standard error [1 SE]) at 12 months and 95.7% +/- 2.2% at 48 months. Including early mortality, survival was 90.1% +/- 2.6% at 12 months and 83.1% +/- 3. 5% at 48 months.

CONCLUSIONS

Aortic root replacement with use of the Carbo-Seal prosthesis can be undertaken with a relatively low early mortality and morbidity. A low reoperation rate and high intermediate-term survival can be expected, but continued follow-up is needed to determine the long-term efficacy of this prosthesis.

Surgery for infective valve endocarditis in children

OBJECTIVE

Surgery for endocarditis in children is relatively uncommon. Our aim is to assess operative mortality, recurrent infection, re-operation and long-term survival rates following surgery for infective valve endocarditis in children.

PATIENTS

Sixteen consecutive children (ten female, six male, mean age 11.8 years, range 25 days-16 years) undergoing surgery between 1972 and 1999 in Southampton were studied. The aortic valve was affected in five, mitral in four, aortic and mitral in one, tricuspid in five and a pulmonary homograft in one patient. Prosthetic valve endocarditis was present in three. Twelve surgical interventions were emergency and four urgent. Indications for operation included cardiac failure in five, severe valvular dysfunction in nine, vegetations in nine, persistent sepsis in four and embolization in four patients. The offending micro-organism was identified in 13. Valve replacement was performed in 11 and excision of vegetations in two and excision of vegetations and repair in three. Follow-up was complete (mean 11.2 years, range 2 months to 26.3 years, total 179.5 patient years).

RESULTS

There was one operative death (6.2%) in a 25-day-old neonate who presented in a moribund condition. Endocarditis recurred in one patient (6.25%). Freedom from recurrent infection at 10 and 20 years was 100.0 and 87.5%. Seven surgical re-interventions were required in four (25.0%) patients with no operative mortality. Freedom from re-operation at 1, 5, 10 and 20 years, was 84.6, 76.1, 76.1 and 60.9%, respectively. Two patients died 15 and 23 years after their first operation. The cause of the late deaths was non-cardiac in the first and unknown in the other. Actuarial survival, including operative mortality, at 1, 15 and 20 years was 93.7, 93.7 and 78.1%.

CONCLUSIONS

Surgery in children with infective valve endocarditis can be performed with low operative mortality. Although some patients may require re-operation, freedom from recurrent infection and long-term survival are satisfactory.

Tricuspid valve replacement: bioprostheses are preferable

BACKGROUND AND AIM OF THE STUDY

Tricuspid valve replacement (TVR) is rarely undertaken, most surgeons preferring to use conservative tricuspid valve procedures. Thus, limited data are available in patients following TVR. The purpose of this study was to analyze the early and late results in 87 patients (52 tissue valves, 35 mechanical prostheses) who underwent TVR between January 1973 and September 1996.

METHODS

The patient group comprised 74 (85%) females and 13 (15%) males; mean (+/- SD) age was 59.4 +/- 12.8 years; range: 15 to 81 years). Forty-four patients (51%) had undergone at least one previous cardiac operation. There were 19 (23%) isolated TVRs, 43 (49%) triple valve replacements, and 25 (29%) double valve replacements. Total cumulative follow up was 707 patient-years (pt-yr) (tissue valves 393 pt-yr, mechanical valves 314 pt-yr); mean follow up was 8.1 years (range: 0 to 23.6 years).

RESULTS

The early (30-day) mortality rate was 10.3% (n = 9; tissue 7, mechanical 2, p = 0.28). Logistic regression identified prolonged cardiopulmonary bypass time (p <0.03) and advanced NYHA functional class (p <0.007) as risk factors for operative death. No risk factors were significant on multiple logistic regression analysis. Mean (+/- SEM) survival rate was 68 +/-5.3% (n = 50) at 5 years, 52 +/- 5.9% (n = 36) at 10 years, 35 +/- 6% (n = 20) at 15 years, and 16 +/- 5.3% (n = 7) at 20 years. Freedom from tricuspid valve reoperation at 5, 10 and 15 years was 93 +/- 3.3% (n = 46), 83 +/- 5.8% (n = 33) and 71 +/- 2.8% (n = 17) respectively. Eleven patients required tricuspid valve reoperation: six mechanical valves (five for prosthetic valve thrombosis and one for mechanical failure secondary to pannus ingrowth), and five tissue valves (two for prosthetic valve endocarditis and three for prosthetic valve degeneration). Freedom from reoperation at 5, 10 and 15 years for tissue prostheses was 97 +/- 2.5%, 89 +/- 6.3% and it was 70 +/- 12%, and 86 +/- 7.4%, 74 +/- 9.9% and 68 +/-11% for mechanical prostheses. The mechanical prostheses required reoperation earlier after the initial surgery.

CONCLUSIONS

We recommend the use of a bioprosthesis in the tricuspid position because of its initial durability and low reoperation rate.

Diagnosis, management, and pathophysiology of post-Fontan hypoxaemia secondary to Glenn shunt related pulmonary arteriovenous malformation

An 8 year old child with tricuspid atresia had developed right sided pulmonary arteriovenous malformations following a previous classic Glenn procedure. These became clinically manifest immediately after Fontan conversion because of severe systemic desaturation. The pathophysiology and postoperative medical management of this case is described and related to current understanding of the aetiology of acquired pulmonary arteriovenous malformations following cavopulmonary shunt.

Twenty-year follow-up of aortic valve replacement with antibiotic sterilized homografts in 200 patients

The aim of this study was to determine long-term results from one unit of subcoronary homograft aortic valve replacement (AVR) using the same sterilization and preservation techniques in each case. Between 1973 and 1983, 200 patients underwent AVR using an unstented homograft previously sterilized in antibiotics and preserved at 4 degrees C. Surviving patients were monitored for a minimum of 15 years to the end of 1998. Mean age was 50.0+/-14 (1 standard deviation) years; 121 patients were men (60.5%). Mean patient follow-up time was 15.6+/-6.7 years, with a total follow-up time of 3,115 patient years. Follow-up was 95.6% complete. There were three early deaths (1.5%). At autopsy, the homograft was anatomically normal and in a satisfactory position. Kaplan-Meier survival, including early death, was 81.2%+/-2.8% (1 standard error) at 10 years, 68.1%+/-3.4% at 15 years, and 58.0%+/-3.7% at 20 years. Repeat AVR was undertaken in 74 patients, giving a freedom from reoperation for any reason of 86.5%+/-2.6%, 69.6%+/-3.8%, and 38.8%+/-5.3% at 10, 15, and 20 years, respectively. Freedom from structural valve degeneration at 10, 15, and 20 years was 81.1%+/-2.9%, 61.7%+/-3.9%, and 31.2%+/-4.7%, respectively. Freedom from endocarditis at 10, 15, and 20 years was 98.7%+/-0.9%, 96.0%+/-1.8%, and 94.6%,+/-2.3%, respectively. Homograft AVR with an antibiotic-sterilized valve stored at 4 degrees C and implanted in the subcoronary position offers low operative mortality and good long-term outcome for patients.

Long-term results of valve replacement using antibiotic-sterilised homografts in the aortic position

OBJECTIVE

Antibiotic-sterilised homograft valves stored at 4 degrees C have been implanted in the subcoronary position in this unit since 1973. This study was undertaken in order to assess the long-term function of these valves.

METHODS

All 249 patients undergoing homograft aortic valve replacement (AVR) at the Wessex Cardiothoracic Centre between April 1973 and December 1994 were studied. Homograft valve sizes ranged from 15 mm to 28 mm internal diameter, 202 (81.1%) varying between 18 mm and 22 mm. The mean patient follow-up was 12.4 years with a total follow-up of 3096 patient-years. There were six early deaths (2.4%).

RESULTS

On actuarial analysis, survival was 78.5+/-2.7% (1SE) at 10 years, 65.7+/-3.3% at 15 years and 55.0+/-3.9% at 20 years. The freedom from redo AVR was 87.9+/-2.4% at 10 years, 71.7 +/-3.8% at 15 years and 49.7+/-5.6% at 20 years. The freedom from structural degeneration was 85.6+/-2.5% at 10 years, 63.6+/-4.0% at 15 years and 41.9+/-6.4% at 20 years. On multivariate analysis the risk of valve failure was significantly higher in younger patients (P<0.0001) and in those who underwent aortic root tailoring (P = 0.024). The freedom from endocarditis was 98.4+/-0.9% at 10 years, 96.2+/-1.6% at 15 years and 95.1+/-1.9% at 20 years. Of the 249 patients, 218 had an isolated homograft AVR and were not anticoagulated. In this group there were two possible thromboembolic events.

CONCLUSION

As well as the established haemodynamic benefits, this study has shown that homograft AVR with antibiotic-sterilised 4 degrees C stored homograft valves implanted in the subcoronary position, offers good long-term results.

Autotransfusion of washed shed mediastinal fluid decreases the requirement for autologous blood transfusion following cardiac surgery: a prospective randomized trial

OBJECTIVES

The National Blood Service issues 2.2 million units of blood per year, 10% of these (220000) are utilized in cardiac procedures. Transfusion reactions, infection risk and cost should stimulate us to decrease this transfusion rate. We test the efficacy of autotransfusion following surgery in a prospective randomized trial.

METHODS

One hundred and twelve patients undergoing CABG, valve or CABG + valve procedures were randomized into two groups. Group A received washed postoperative drainage fluid and group C were controls. The indication for transfusion was a postoperative haemoglobin (Hb) < 10 g/l or a PCV < 30. There was no significant difference in preoperative and operative variables between the groups.

RESULTS

Twenty-eight patients in group A and 46 in group C required homologous transfusion (P = 0.0008). Group A patients required 298+/-49 ml of banked blood per patient, group C 508+/-49 ml (P = 0.003). There was no difference in total blood required (volume autotransfused + volume banked blood transfused) between the groups (group A 404+/-50 ml, group C 508+/-50 ml) or in mean total mediastinal fluid drainage (group A 652+/-51 ml, group C 686+/-50ml). The mean Hb concentration was significantly higher in group A on day 1 (11.2 g/dl+/-51 vs. 10.6 g/dl+/-13 (P = 0.002)). No morbidity was associated with autotransfusion.

CONCLUSION

Autotransfusion can decrease the amount of homologous blood transfused following cardiac surgery. This represents a benefit to the patient and a decrease in cost to the health service.

Induced hypothermia as salvage treatment for refractory cardiac failure following paediatric cardiac surgery

OBJECTIVE

Following corrective cardiac surgery in infants and children for congenital heart disease, a persistent low cardiac output refractory to conventional modes of treatment is associated with a mortality approaching 100%. We advocate the use of whole body hypothermia to reduce tissue oxygen demand and provide a degree of cellular protection against ischaemia allowing time for recovery. We describe our experience.

METHODS

Between July 1986 and December 1995, 1885 infants and children underwent surgery (operative mortality, 6%), 1302 requiring cardiopulmonary bypass. Fifty-seven patients had a persistent low cardiac output, impaired respiratory function, decreased urine output and acidosis despite maximal intensive care treatment. Cooling to 32-33 degrees C was therefore started using a thermostatically controlled water filled cooling blanket.

RESULTS

Following cooling, there was a fall in heart rate (P<0.001), a rise in mean arterial pressure (P<0.001) and a fall in mean atrial pressure (P<0.001). Significant (P<0.001) increases in pH and urine output were also recorded. Thirty-one (54%) of the 57 patients treated with cooling survived to leave hospital. No long-term sequelae have been noted in these patients.

CONCLUSION

Induced hypothermia is a useful salvage treatment, in children following corrective cardiac surgery when all conventional treatment has been tried and failed.

Degenerative mitral regurgitation: when should we operate?

BACKGROUND

Left untreated, severe mitral regurgitation in asymptomatic patients can lead to irreversible cardiac damage, which can develop with little warning. Over the period of this study, we have tended to operate earlier in the disease process and on less symptomatic patients. We report here our experience.

METHODS

Between January 1985 and June 1996, 710 patients with mitral regurgitation underwent operations. Three hundred twenty-nine (213 male and 116 female with a mean age of 65.5 years) had degenerative mitral valve disease and of this group, 169 patients underwent repair and 160, replacement.

RESULTS

The overall operative mortality was 4 patients (1.2%). There were no operative deaths among patients having isolated mitral valve repair. Survival at 1 year, 5 years, and 10 years was 94%+/-1.4% (+/- the standard error of the mean), 77%+/-2.9%, and 41%+/-5.8%, respectively. Survival was significantly better in the group having repair (p < 0.05). Ten patients (6%) in the repair group and 13 (8%) in the replacement group required reoperation. Increased age, worse left ventricular function, type of operation (replacement worse than repair), and increased left ventricular size were significantly associated with poorer survival.

CONCLUSIONS

These data confirm the superior results achieved with mitral valve repair and support early mitral valve repair before functional deterioration.

Induced hypothermia in the postoperative management of refractory cardiac failure following paediatric cardiac surgery

Postoperative low cardiac output states are a major cause of postoperative mortality in infants and children following corrective cardiac surgery for congenital heart defects. In this unit, whole body hypothermia has been used since 1979 in the management of these low output states when they are refractory to conventional modes of therapy. Twenty cases treated in this way between July 1986 and June 1990 were reviewed in 1992. The current report reviews the 50 further cases treated with moderate hypothermia between July 1990 and December 1995. The median (range) age of patients was 8 months (0 days-16 years) with a median weight of 4.1 kg (2.5-33 kg). Following cooling, there was a decrease in heart rate (p < 0.001), an increase in mean arterial pressure (p < 0.001) and a decrease in mean atrial pressure (p < 0.001). Significant increases in pH and urine output were also noticed, the increase in urine output being greater in the surviving group (p = 0.02). A decrease in platelet count occurred (p < 0.001) but white blood cell count remained unchanged (p = 0.18). Twenty-five of the 50 patients survived to leave hospital. Induced hypothermia does not appear to be associated with any complications and after the failure of all conventional treatment, it seems likely that the technique may have been beneficial to outcome in some patients.

Right ventricular function and exercise performance late after primary repair of tetralogy of Fallot with the transannular patch in infancy

To evaluate the late effects of chronic pulmonary regurgitation against the putative benefits from the current surgical trend of primary repair of tetralogy of Fallot with a transannular patch in infancy, 10 patients > 10 years after early primary repair and 7 matched normal controls underwent exercise stress test and cine magnetic resonance imaging assessment of ventricular functions. Right ventricular impaired diastolic function and decreased exercise capacity, both significantly associated with pulmonary regurgitation in patients, indicated that early primary repair of tetralogy may not prevent late ventricular dysfunction and diminished exercise performance if chronic regurgitation results from right ventricular outflow tract reconstruction.

When is extracorporeal life support worthwhile following repair of congenital heart disease in children?

BACKGROUND

Although the use of extracorporeal life support (ECLS) following repair of congenital heart defects in children is increasing, the criteria for ECLS usage in these patients is not well defined. The overall survival of such patients is disappointingly low and may depend on both the indication for support and the time at which ECLS is commenced.

METHODS

Between January 1993 and December 1996, 727 children underwent surgery for congenital heart defects at our institution with an overall hospital mortality of 5.8% (42 children). Nine of these children were treated with ECLS postoperatively. There were seven males and two females with a mean age of 7.2 months (range 2 weeks-3 years). Seven children could not be weaned from cardiopulmonary bypass (CPB) in the operating theatre. A further two were treated with ECLS later on during the postoperative period (commenced at 14 and 48 h). Full veno-arterial extra corporeal membrane oxygenation (ECMO) support was used in all children except one in whom a left ventricular assist device (LVAD) was used.

RESULTS

The median duration of support was 121 h (range 15-648 h). Four children (44%) were weaned from support and two of these are long-term survivors. Of the seven children in whom ECLS was instituted because of failure to wean from CPB, there was one long term survivor (LVAD support). Of the two patients in whom ECLS was instituted during the post-operative period there is one long-term survivor.

CONCLUSIONS

Weaning form ECLS and decannulation in 44% of our patients is comparable to other series of post-cardiotomy patients requiring ECLS. However, full veno-arterial ECMO instituted because of a failure to wean from CPB during corrective surgery is associated with an extremely poor outcome (zero long-term survivors in six patients).

Effects of angiotensin converting enzyme inhibition on systemic vascular resistance and vasoconstrictor requirements during hypothermic cardiopulmonary bypass

OBJECTIVE

We proposed that angiotensin converting enzyme (ACE) inhibitor therapy would alter systemic vascular resistance (SVR) during rewarming and increase the requirement for vasoactive drugs in the immediate post-bypass period.

METHODS

Sixty-five sequential adult patients undergoing cardiac surgical procedures requiring hypothermic (28 degrees C) cardiopulmonary bypass (CPB) were recruited. Sixty-two fitted the inclusion criteria of which 21 were receiving ACE inhibitors prior to surgery. SVR was calculated at 1 min intervals during the rewarming phase of hypothermic CPB. The use of vasoactive drugs during and immediately after termination of CPB was recorded. The doctor administering these drugs was unaware of the nature of the study.

RESULTS

Mean SVR in the ACE group was 978 dyne/s per cm5 and in the control group was 1194 dyne/s per cm5 (P = 0.006). Mean arterial pressure was 48.8 mmHg in the ACE group and 56.3 mmHg in the control group (P = 0.004). There was a significant difference in vasoactive drug requirements between the groups (P < 0.01). There was no statistically significant difference in age, weight, body mass index, body surface area, theatre temperature, core temperature at which rewarming started, rate and time of rewarming, haematocrit on bypass or preoperative left ventricular function.

CONCLUSION

Preoperative ACE inhibitor therapy decreases SVR during the rewarming phase of CPB and increases post-bypass vasoactive drug requirements.

Surgery for congenital heart disease in Europe 1995

OBJECTIVE

An attempt was made to find out how many operations were performed in Europe in 1995 for congenital heart disease.

METHODS

Representatives from the 20 most active European countries which could supply reliable information were contacted. They were asked to contact all surgeons performing significant numbers of operations for congenital heart disease in their country. The numbers of operations on children under and over 1 year operated on with and without cardiopulmonary bypass were collected. No attempt was made to collect more detailed information such as operative mortality as it was felt that many surgeons would be reluctant to give their results and the data would be incomplete.

RESULTS

A total of 27,976 operations were recorded, of which 20,318 were performed with cardiopulmonary bypass and 7658 without. The total population of the 20 European countries was 448 million and the mean number of operations performed with cardiopulmonary bypass per million was 45.4. However, the rate varied from 9.1 to 70.1. The percentage of operations on cardiopulmonary bypass performed in the first year of life varied from 9.4% to 44.4%.

CONCLUSIONS

The total of nearly 28,000 operations in 1995 is probably an underestimate, but it has been difficult to collect this data at all. Obviously many smaller countries have not been included, and some older patients undergoing operations such as atrial septal defect closure in adult units have been missed. The number of open heart operations per million vary in different countries and this presumably represents differing referral patterns. If their numbers are low in some countries, these results may be helpful in persuading their governments that more resources are needed for congenital heart surgery. It is also interesting to see the variation in the number of operations performed in the first year of life. Those countries with a lower rate may have a backlog of older patients who were previously palliated, or their surgeons may still prefer initial palliation and later correction in some conditions rather than early correction. It is hoped that with better prospective data collection, an assessment can be repeated in 2000.

Postinfarction ventricular septal rupture: the Wessex experience

Surgical repair of a postinfarct ventricular septal defect (VSD) remains a difficult surgical challenge associated with a significant operative mortality. Between 1972 and 1995, 179 patients with a postinfarct VSD have undergone operation in this institution. There were 118 males and 61 females, with a mean age of 66 years (range 43 to 80). Operative mortality was 26.7%. Surgery was deferred until 1 month after the septal rupture in 29 patients, with these labeled as having a chronic VSD. The remaining 150 underwent operation on within 1 month of infarction and are described as having an acute VSD. For those with an acute VSD, factors significantly associated with an increased risk of 30-day mortality included preoperative New York Heart Association status (P = .04), site of myocardial infarction (inferior worse than anterior) (P = .004), cross-clamp time (P = .05) and cardiopulmonary bypass time (P = .0001) (logistic regression). On multiple logistic regression, only cardiopulmonary bypass time remained significant. Survival including in-hospital mortality at 5 and 10 years was 49% +/- 4% and 31% +/- 5% and excluding in-hospital mortality was 72% +/- 5% and 45% +/- 6%, respectively. Those patients who survived attained a good quality of life. No factors were significantly associated with prolonged survival.

Cerebral oxygenation during paediatric cardiac surgery: identification of vulnerable periods using near infrared spectroscopy

OBJECTIVE

Neurologic sequelae remain a well recognised complication of paediatric cardiac surgery. Monitoring of cerebral oxygenation may be a useful technique for identifying vulnerable periods for the development of neurologic injury. We sought to measure regional cerebral oxygenation in children undergoing cardiac surgery using near infrared spectroscopy to ascertain such vulnerable periods.

METHODS

Observational study of 18 children (median age 1.3 years) undergoing cardiac surgery (17 with cardiopulmonary bypass, 8 with circulatory arrest). Regional cerebral oxygenation was monitored using the INVOS 3100 cerebral oximeter and related to haemodynamic parameters at each stage of the procedure.

RESULTS

Prior to the onset of bypass, 10 patients had a decrease in regional cerebral oxygenation of > or = 15% points, reaching an absolute haemoglobin saturation less than 35% in 5 cases. The most common cause was handling and dissection around the heart prior to and during caval cannulation. With institution of bypass, regional cerebral oxygenation increased by a mean 18% points to a mean maximum of 75%. During circulatory arrest regional cerebral oxygenation decreased with rate of decay influenced by temperature at onset of arrest (0.25%/min at < 20 degrees C; 2%/min at > 20 degrees C). Reperfusion caused an immediate increase in regional cerebral oxygenation followed by a decrease during rewarming. Discontinuation of bypass caused a precipitous decrease in regional cerebral oxygenation in 5 patients, reaching less than 50% in 3 patients.

CONCLUSIONS

These observations suggest that the pre- and early post-bypass periods are vulnerable times for provision of adequate cerebral oxygenation. Near infrared spectroscopy is a promising tool for monitoring O2 supply/demand relationships especially during circulatory arrest.

Should coronary artery bypass grafting be performed at the same time as repair of a post-infarct ventricular septal defect?

OBJECTIVE

The value of coronary artery bypass grafting (CABG) at the time of repair of a post-infarct ventricular septal defect (VSD) remains controversial. The aim of this study was to analyse the effect of CABG on early mortality and survival following repair of an acquired VSD.

METHODS

Over 23 years, 179 patients, 118 male, 61 female, mean age 66 years (range 43-80), have undergone repair of a post-related VSD in our unit. A total of 29 patients, who predominantly form the earlier part of the series, were operated on greater than 1 month after the infarct and are, therefore, excluded. Coronary angiography was performed in 98 (65.3%) of the remaining 150 patients. Of these, 41 had coronary artery disease (CAD) limited to the infarct-related vessel and 57 had additional significant CAD. Those with CAD limited to the infarct-related vessel were not grafted (Group A). Of those, 40 with significant CAD underwent CABG at the time of VSD repair (Group B) and 17 did not (Group C). In 52 patients the coronary anatomy was not documented (Group D). Risk factors for early mortality were evaluated using logistic regression. Actuarial survival was compared using log rank and Wilcoxon tests. Cox's proportional hazards method was used to determine factors affecting survival.

RESULTS

Overall, 30 day mortality was 32%. CABG did not significantly decrease operative mortality (logistic regression). There was no statistically significant difference in early mortality or actuarial survival between the four groups. CABG was not associated with an increased survival (Cox's method).

CONCLUSIONS

Concomitant CABG at the time of VSD repair does not affect early mortality nor confer survival benefits. There seems to be no demonstrable benefit in revascularisation at the time of repair and, therefore, it may be unnecessary to perform CABG or coronary angiography in these patients.

Migration of pectus excavatum correction bar into the left ventricle

We present the case of a 19-year-old student who underwent correction of a pectus excavatum deformity using a pectus bar. At least 6 months following surgery, one end of the bar had migrated into his right ventricle, across the interventricular septum, to lie with its free end in the left ventricular cavity. This acted as a source of thrombus formation and lead to several systemic embolic events. The patient made a full recovery after removal of the bar. A review of the literature demonstrates that this has not been reported before.

Surgical treatment of acquired ventricular septal defects in the elderly

OBJECTIVE

As the population continues to age, older patients are being referred for repair of acquired ventricular septal defect (VSD) following myocardial infarction (MI). The purpose of this study was to assess the effect of age (> or = 70 years) on operative risk and long term survival following repair of an acquired VSD.

METHODS

Between January 1972 and December 1995, 179 patients have undergone repair of acquired VSDs following MI in our unit. There were 118 males and 61 females (age range 43-80 years) of whom 60 were aged 70 years or above.

RESULTS

The overall early mortality was 27%. On univariate analysis risk factors for early death included shorter time from both MI and detection of murmur to operation (P < 0.01, P = 0.04), site of MI (P < 0.01), higher NYHA class (P < 0.01), lower preoperative blood pressure (P < 0.01) and longer cardiopulmonary bypass and cross clamp times (P < 0.01, P = 0.03). Non significant variables included age, sex, concomitant CABG and preoperative renal function. Early mortality was 28.6% (34/119) in patients under 70 and 25.0% (15/60) in those over 70. This difference was not significant. The only significant differences between the age groups were sex distribution (females > males, P < 0.01), in the older group, and shorter time from both MI and detection of murmur to operation (P = 0.04, P = 0.02). Cardiopulmonary bypass was the only statistically significant variable on multivariate analysis (P = 0.01).

CONCLUSIONS

There was no significant difference in early mortality between the two age groups. As shorter times from both MI and detection of murmur to operation adversely affect early mortality, age over 70 years should not be used to determine suitability for surgery.

Prospective study of the value of necropsy examination in early death after cardiac surgery

OBJECTIVE

To assess the value of necropsy examination in patients dying soon after cardiac surgery, particularly the proportion of clinical questions answered by the necropsy, the frequency of major unexpected findings, and the limitations of the procedure.

DESIGN

A three year prospective study of necropsy examinations in adult patients dying before discharge or within 30 days of cardiac surgery performed under cardiopulmonary bypass in one hospital.

SETTING

Tertiary referral centre.

RESULTS

123 of 2781 patients (4.4%) died in the early postoperative period, and necropsy examination was performed in 108 of these (88%). The mortality after emergency procedures (18%) was much higher than after routine operations (2.6%). The main causes of death were cardiac failure (52%), haemorrhage (14%), cerebral disease (6%), and pulmonary emboli (5%). The necropsy changed the stated cause of death in 16 patients (15%), and answered clinical questions in 24 of 38 patients. In 15 patients necropsy examination did not provide a full explanation of death. Most of these patients died of cardiac failure soon after surgery or were sudden unexpected deaths.

CONCLUSIONS

Necropsy examination in patients dying early after cardiac surgery is valuable as it answers the majority of clinical questions, and shows unexpected findings in a significant proportion of cases.

Twenty-year follow-up of acute type a dissection: the incidence and extent of distal aortic disease using magnetic resonance imaging

A persistent distal false lumen (PDFL) after surgical repair of type A aortic dissection is the most important factor in determining long-term survival. It has been suggested that changes in surgical technique reduce the incidence of distal false lumen. We report the findings of a 20-year follow-up (mean 5.2 years) on 87 patients who have undergone surgical repair of type A aortic dissection with all survivors undergoing magnetic resonance (MR) scanning of the entire aorta. Early mortality was 27.5%, and actuarial 5-, 10-, and 15-year survival was 65%, 28% and 20% respectively. Early mortality had decreased to 18% in the last 5 years. The most common cause of late death was related to distal aortic disease, accounting for 47% of all late deaths with a peak incidence at 7-10 years after surgery. The incidence of PDFL in survivors was 72%, despite the fact that 82% of all intimal tears were resected at time of operation. Incidence was not affected by extension of the repair into the aortic arch nor by the use of the open technique or Gelatin-Resorcine-Formal tissue glue. In patients with a distal false lumen 6% had reached a maximum aortic diameter of 6 cm in at least one plane on MR scanning and 25% had reached 5 cm. We conclude that if dissection has extended beyond the arch at time of presentation then the choice of surgical technique does not prevent the persistance of a distal false lumen. MR scanning gives ideal anatomical and functional assessment of distal aortic disease and provides the surgeon with all the necessary information to plan the timing and indications for further surgery.

Aortic valve repair of congenital stenosis with bovine pericardium

BACKGROUND

Conservative surgical options in the treatment of congenital aortic stenosis are limited. To relieve the obstruction necessitates full incision of the raphe of the larger valve leaflet, but this inevitably causes prolapse.

METHODS

We performed aortic valve repair in 6 children, aged 14 months to 17 years, with congenital aortic stenosis, 2 having had aortic valvotomy as infants. The repair consisted of suturing the base of a triangular piece of bovine pericardium, with a simple vertical fold, to the free edges of the incised raphe. The pericardial fold was then sutured vertically to the aortic wall.

RESULTS

At follow-up of 2 to 60 months, the mean peak systolic Doppler gradients had decreased from 80 +/- 15 mm Hg to 26 +/- 9 mm Hg. The effective valvular orifice area increased from 33% +/- 6% to 64% +/- 3%, allowing blood flow to increase by a factor of 3.76. Two patients have mild and 2 have mild-to-moderate aortic regurgitation.

CONCLUSIONS

The described conservative repair renders the valve tricuspid and trisinusoidal, and the deficient interleaflet triangle is recreated, preventing cusp prolapse. Longer follow-up is required to assess the durability of unstented pericardium in the aortic position, but the early results are encouraging.

Growth potential in the new aortic arch after non-end-to-end repair of aortic arch interruption in infancy

BACKGROUND

Complete repair of infants with interrupted arch and ventricular septal defect through a midline incision has been the preferred method for more than 20 years. End-to-end anastomosis can result in restenosis if there is excess tension. Two methods of reducing this tension have been described, and the subsequent growth of the new aortic arch is demonstrated.

METHODS

In 2 infants (5 and 9 months old) the duct was used to create a new aortic arch. In 3 other younger infants the left carotid artery was divided, turned down, and anastomosed to the descending aorta to form the new arch. These operations were performed through the midline at the same time as the ventricular septal defect was closed.

RESULTS

All 5 patients are well now 8 to 19 years postoperatively. One patient required reoperation for stenosis at the anastomotic site, but all have subsequently shown good growth on follow-up angiographic and magnetic resonance imaging studies.

CONCLUSIONS

Although end-to-end repair is best, these alternative methods have shown very satisfactory aortic growth into adult life.

Bidirectional superior cavopulmonary anastomosis: how young is too young?

OBJECTIVE

To define the lowest age at which the bidirectional superior cavopulmonary anastomosis can safely be used in infants with complex congenital heart defects.

DESIGN

A retrospective analysis of clinical, echocardiographic, haemodynamic, and angiographic data in four consecutive patients undergoing bidirectional superior cavopulmonary anastomosis below the age of 2 months.

PATIENTS

Between November 1990 and September 1993, four infants less than 8 weeks of age (3, 4, 6, and 7 weeks) underwent bidirectional superior cavopulmonary anastomosis as a primary palliation for complex heart disease. The indication for early surgical intervention was progression of cyanosis (n = 3) and high pulmonary blood flow causing heart failure (n = 1). In two infants with tricuspid atresia, surgery was performed through a right thoracotomy without the use of cardiopulmonary bypass. In one infant with double inlet left ventricle and discordant ventriculoarterial connection, cavopulmonary anastomosis was combined with an arterial switch procedure. The final infant had double inlet left ventricle with pulmonary atresia; the central pulmonary arteries were virtually discontinuous and each branch was supplied by a separate arterial duct. The central pulmonary arteries were reconstructed using the subaortic innominate vein. Temporary prostacyclin infusion was used in three patients in the immediate postoperative period.

RESULTS

Early postoperative extubation (5, 7, and 48 h) was successful in three patients. The youngest child required ligation of the ductus arteriosus four days later because of severe upper body oedema. The postoperative course was complicated by prolonged effusions in two patients. All were alive and well 14-48 months postoperatively, with satisfactory systemic saturations (80-87%) and haemodynamic indices.

CONCLUSIONS

This limited experience challenges the widely held belief that the bidirectional superior cavopulmonary anastomosis cannot be used as a primary palliation for complex heart disease in early infancy. A wider experience is required to determine the safety and indications for this approach.

Technique for extraanatomic bypass in complex aortic coarctation

A variety of approaches and surgical techniques have been described for the management of recurrent coarctation. When there is an additional intracardiac defect that requires surgical correction it is preferable to correct both lesions simultaneously and through the same incision. This article reports two new techniques of connecting ascending to descending aorta using an intrathoracic conduit and performed through a median sternotomy.

Influence of bidirectional superior cavopulmonary anastomosis on pulmonary arterial growth

Right-sided BSCA provides for satisfactory pulmonary arterial growth in infants and children with complex congenital heart defects, and it could enhance the growth of a small right pulmonary artery. The growth of the left pulmonary artery, particularly in younger patients, needs close attention to confirm the safe role of BSCA in long-term palliation.