Reconstruction of the RVOT with valved biological conduits: 25 years experience with allografts and xenografts.

OBJECTIVE: The reconstruction of the RVOT in congenital heart disease often requires the implantation of a valved conduit. Although allografts are considered the conduit of choice their availability is limited and therefore xenografts are implanted as well. We compared the long-term durability of both grafts in the RVOT over a 25-year period. METHODS: Between January 1974 and August 1999, 505 patients (median age 4.0 years, range 2 days-31 years; median weight 14.5 kg, range 2.2-76.6 kg; median body length 103 cm, range 48-183 cm) with congenital malformations (PA 25.3%, TOF 14.5%, TOF+PA 2.4%, DORV 4.2%, TGA+PS 8.7%, TAC 24.8%, and other 20.2%) received their first valved conduit (174 xenografts: median diameter 14 mm, range 8-27 mm; 331 allografts: median diameter 19 mm, range 8-30 mm). RESULTS: Follow-up is 3017 patient-years. The 10-year survival-probability for all patients. was 66% with a mean reoperation-free interval for conduit-exchange of 13.3 years (mean reoperation-free interval for allografts, 16.0 years; mean reoperation-free interval for xenograft, 10.3 years). One hundred and thirteen patients underwent a conduit-exchange, mostly due to conduit stenosis. Fourteen patients had a second exchange and three patients a third exchange. For patients with conduit diameters <18 mm (n=235: allograft n=116, xenograft n=119; median age 9 months, range 0-27.3 years), the mean reoperation-free interval was 11.2 years (mean interval allograft, 13.1 years; mean interval xenograft, 8.6 years, P=0.03). For conduit diameters >/=18 mm (n=270: allograft n=215, xenograft n=55, median age 7.4 years, range 0-34.3 years) the mean interval from freedom of conduit exchange was 15.1 years (for allografts 14.1 years, for xenografts 12.5 years, P<0.01). Comparing xenografts to allografts, we found no difference in patient survival probability (P=0.62). There was no significant difference between antibiotic (n=198) preserved vs. cryopreserved (n=133) allografts (P=0.06). Blood group compatibility of allografts to recipients had no significant influence on allograft function (P=0.42). The donors allograft origin, whether aortic or pulmonary valve, had also no significant influence on allograft long-term function (P=0.15). CONCLUSION: For the reconstruction of the right ventricular outflow tract (RVOT) allografts show significantly better long-term durability than xenografts regardless of the age at implantation and the diameter.

Exercise capacity and mid-term survival in patients with tricuspid atresia and complex congenital cardiac malformations after modified Fontan-operation.

OBJECTIVE: Continued follow-up of the Fontan population group is mandatory in order to evaluate the best approach for long term treatment. We studied exercise capacity and survival in patients with either right atrial to right ventricular (Fontan-Bjoerk, RA-RV) anastomosis or right atrial to pulmonary artery (RA-PA) connection. METHODS: Between January 1980 and December 1995 Fontan-Bjoerk modifications were performed in 73 patients with tricuspid atresia. A RA-PA anastomosis (performed either with direct atrio-pulmonary connection or with a lateral tunnel of autologous atrial tissue) was used in 118 patients with single ventricle or complex cardiac malformations. Using bicycle ergospirometry and impedance cardiography standard variables of exercise testing were measured in 15 patients with RA-RV and in 18 patients with RA-PA connection. A group of 23 healthy pupils served as controls. RESULTS: Follow-up was complete for 97.9% (n = 187) of all operated patients. Survival (% mean +/- SEM) at 5, 10 and 15 years was 89.3 +/- 3.6, 76.8 +/- 0.6 and 63.6 +/- 10.5 for RA-RV connection and 80.2 +/- 4.0, 75.3 +/- 4.5 and 64.6 +/- 10.7 for RA-PA connection (P = 0.12) respectively. Exercise capacity was tested after a median time of 6.0 (0.8-19.8) years after Fontan operation in RA-RV and of 7.8 (4.3-18.2) years in RA-PA patients. Total work load was equal in the two Fontan groups, but it was below normal. Heart rate, respiratory rate, oxygen uptake and ventilatory equivalent for oxygen were not different between the two Fontan groups. Cardiac index and stroke volume index were consistently lower at anaerobic threshold and at maximal exercise in RA-PA patients compared with controls. CONCLUSION: Survival analysis between RA-RV and RA-PA Fontan connection failed to demonstrate a better outcome for patients with either Fontan modification. Although there was a tendency for RA-RV connection to adapt cardiac output more efficient to exercise compared with RA-PA patients, total work load and ventilatory equivalent was not significantly different between the two Fontan modifications. We conclude, that by incorporation of a residual subpulmonary ventricular chamber within the Fontan circulation no additional benefit for exercise capacity could be observed.

The interrupted aortic arch: an overview after 20 years of surgical treatment.

OBJECTIVE AND METHODS: The records of 95 patients with interrupted aortic arch, admitted to our center from 1975 to 1995, were reviewed. We were particularly interested in the long term results and evaluated the impact of the preoperative state on the outcome after surgery. RESULTS: Using the 'Celoria and Patton' classification, 13% were type A, 84% type B and 3% type C. Among various associated anomalies were ventricular septal defects and left ventricular outflow tract obstructions, either subvalvular or due to a hypoplastic annulus or a bicuspid valve. We have also seen complex malformations such as truncus arteriosus communis, double outlet right ventricle and transposition of the great arteries. Preoperative neurological disorders, among them the Di George's syndrome, were found in 29% of the cases. Our long term results show 52 patients to be alive, of which 89% are in good clinical condition. Due to improved operative techniques and changes in the management of neonates respectively, early mortality was 17% between 1985 and 1995 compared to 42% between 1975 and 1985. Reoperations were necessary due to arch stenosis, compression of the bronchus or left ventricular outflow tract obstruction. CONCLUSIONS: Nevertheless, mortality after surgical repair of an interrupted aortic arch has dropped significantly and the preoperative condition plays an important role in the outcome. Sepsis, low output, low weight (under 2400 g), severe left ventricular outflow tract obstruction and complex malformations impeded surgery in 13% of cases. Immediate surgical intervention is the only therapy. Arch continuity and repair of associated anomalies could be achieved in the remaining collective. Most of the children have a good quality of life. The preoperative condition seems to influence late neurological disorders.

Implications of the introduction of fixed reimbursement rates in Germany.

The introduction of fixed reimbursement rates in Germany for cardiac surgery of adults, mainly coronary artery bypass grafting (CABG) and valve surgery, has shifted the financial risk from insurers to providers of medical care, namely hospitals. Costs in turn are closely related to the preoperative condition of a patient, implicating that surgery in high-risk patients may result in financial losses for the operating institution. Furthermore, reports from the Society of Thoracic Surgeons national database indicate a trend over time towards a higher proportion of patients with adverse risk factors for the United States. To determine whether these trends are holding true for Germany, we conducted an analysis of the data from two institutions with the following questions: 1. Is there a trend over time towards unfavourable risk factors, and 2. Is there a relation between preoperative risk factors and postoperative length of stay? From 1987 to 1995, 3872 patients underwent CABG at the Departments of Cardiovascular Surgery of Justus-Liebig University Giessen and German Heart Center Munich. Medical history, preoperative condition, intra-, and postoperative course were recorded for these patients according to the protocol of the German quality assurance program. Preoperative condition of the patient was summarized with an additive risk score. The correlation between postoperative length of stay in the intensive care unit (ICU) and preoperative risk was investigated. For a subgroup of 30 patients, detailed cost analysis was performed and the relationship to preoperative risk examined. For all risk factors examined, a significant increase in prevalence between 1987 and 1995 was observed. A close correlation between preoperative risk and postoperative length of stay in the ICU was found. A similar correlation existed between preoperative risk and actual costs of treatment. In addition, high-risk patients had a significantly higher likelihood of being discharged directly from our ICU to the ICU of other hospitals. Postoperatively, high-risk patients suffer more often from morbidity with subsequent prolonged intensive care and are, therefore, a financial burden for the operating institution in a reimbursement system with fixed rates. This is aggravated by the fact that a trend towards adverse risk profiles among patients undergoing cardiac surgery can be observed. Both factors combined may result in a scenario where those who would benefit most are denied surgical treatment.

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)

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)