Evaluation of the extracardiac conduit modification of the Fontan operation for thrombus formation using magnetic resonance imaging.

BACKGROUND: The prevalence of thrombosis after the Fontan procedure depends upon the surgical technique used and the method of detection employed. Current investigations for thrombosis lack sensitivity and specificity or, in the paediatric population, require a general anaesthetic. We undertook a study to examine the feasibility of using magnetic resonance imaging (MRI) to detect thrombosis within the conduit, cardiac chambers and pulmonary arteries after the extracardiac conduit modification of the Fontan procedure. METHODS: Of the 50 children who had undergone this procedure at our institution between 1997 and 2002, 26 were eligible for, and 13 underwent, MRI study. The mean age was 10.2 years (range 8.2-16.8 years, median 9.5 years) and the average time from operation was 63 months (range 29-79 months, median 68 months). The mean age at Fontan operation was 4.9 years (range 2.1-10.5 years). Ten were on low dose aspirin, two were on warfarin and one was not anti-coagulated. In all cases, satisfactory imaging of the venous pathways and pulmonary arteries was obtained and there were no thrombi detected. CONCLUSIONS: We conclude that MRI is a potentially useful tool for the detection of thrombus in patients who have undergone the Fontan operation.

Abnormal right ventricular tissue velocities after repair of congenital heart disease--implications for late outcomes.

BACKGROUND: Although repair of Tetralogy of Fallot (TOF) and transposition of the great arteries (TGA) has facilitated survival into adulthood, many survivors have residual haemodynamic abnormalities, including exercise intolerance and late right ventricular (RV) failure. METHODS: We studied 40 asymptomatic adult subjects (31.3+/-1.5 years) after congenital heart disease (CHD) surgery during childhood, using tissue Doppler echocardiography (TDE). We compared systolic (S') and diastolic (E' for early filling) RV and LV velocities, with 40 age matched controls (29.5+/-1.0 years). RESULTS: Both RV S' and E' velocities were significantly slower in the CHD group compared to controls (6.3+/-0.4 cm/s vs. 9.3+/-0.3 cm/s; 8.5+/-0.5 cm/s vs. 10.9+/-0.4 cm/s, respectively, p<0.001 for both). By contrast, LV S' and E' velocities were similar in both groups. Interestingly, in 50% of CHD subjects where RV function was reported as 'normal', both RV S' and E' velocities were significantly slower compared with controls (6.5+/-0.6 cm/s vs. 9.3+/-0.3 cm/s, p<0.0001 and 9.4+/-0.7 cm/s vs. 10.9+/-0.4 cm/s, p<0.05 respectively). CONCLUSIONS: RV S' and E' velocities are frequently abnormal in asymptomatic survivors of TOF and TGA repair, even where RV function appears 'normal'. Hence TDE during follow up may be a sensitive means of detecting pre-clinical abnormalities in RV performance.

Gregg's congenital rubella patients 60 years later.

BACKGROUND: In 1941, a Sydney ophthalmologist, Norman McAlister Gregg, correctly identified the link between congenital cataracts in infants and maternal rubella early in pregnancy. Fifty of Gregg's subjects with congenital rubella, born in 1939-1944, were reviewed in 1967 and again in 1991. We reviewed this cohort in 2000-2001, 60 years after their intrauterine infection. METHODS: The subjects underwent full clinical assessment, plus pathology tests, an ophthalmological and cardiological review (including electrocardiography and echocardiography) and HLA histocompatibility testing. RESULTS: Since they were first seen in 1967, 10 have died (cardiovascular causes [4], malignant disease [4], AIDS [1], and hepatitis C-related cirrhosis [1]). All surviving men came for review (19) and 13 women (eight women declined). Echocardiography showed mild aortic valve sclerosis in 68%. The prevalence of diabetes (22%), thyroid disorders (19%), early menopause (73%) and osteoporosis (12.5%) was increased compared with the Australian population; 41% had undetectable levels of rubella antibodies. The frequency of HLA-A1 (44%) and HLA-B8 (34%) antigens was increased, and the haplotype HLA-A1, B8, DR3, said to be highly associated with many autoimmune conditions, was present in 25%. CONCLUSIONS: This cohort of people with congenital rubella has illuminated our understanding of viral teratogenesis.