Benefits of screening in von Hippel-Lindau disease--comparison of morbidity associated with initial tumours in affected parents and children.

Von Hippel-Lindau (VHL) is a rare autosomal dominant syndrome characterised by the association of retinal and CNS haemangioblastomas, phaeochromocytoma and renal cell carcinoma. If a child of an affected parent has inherited a VHL mutation or the parent's mutation cannot be identified, then clinical screening is recommended. We report the clinical features in three parent-offspring pairs where the parents have presented clinically with renal cell carcinoma, phaeochromocytoma, cerebellar haemangioblastoma and retinal haemangioma, and the children have undergone pre-symptomatic screening. During the first screening a 13-year-old boy was diagnosed with bilateral phaeochromocytoma and later developed an endolymphatic sac tumour at 19 years. A right phaeochromocytoma was found in a 12-year-old girl who was screened from the age of 4 years and in a 13-year-old boy screened from 5 years of age. All children were asymptomatic at the time of diagnosis. These families demonstrate that clinical screening of children at risk of VHL can detect tumours before the first symptoms arise with a consequent reduction in morbidity. These observations strongly support the recommendation to undertake screening of the children of VHL patients.

Circulatory arrest and renal function in open-heart surgery on infants.

This study was designed to evaluate the impact of circulatory arrest on renal function in open-heart surgery on infants. Renal function was described by diuresis, urine/plasma creatinine ratio, creatinine clearance, urinary albumin, and N-acetyl-beta-D-glucosaminidase measurements. Seven patients who underwent circulatory arrest (group 1) were compared with 37 patients operated on with cardiopulmonary bypass without circulatory arrest (group 2). In group 1, bypass time was 164 minutes and the lowest body temperature was 25.6 degrees C (median), compared with 106 minutes and 31.3 degrees C in group 2 (p < 0.05). Although diuresis and creatinine clearance revealed no differences between the groups, urine measurements, which had normal values before cardiopulmonary bypass, increased during reperfusion to 58.6 (range 16.2-75.5) mg gCrea(-1) albumin and to 14.8 (range 1.6-21.8) U gCrea(-1) N-acetyl-beta-D-glucosaminidase in group 1, compared with 8.1 (range 0-127.7) mg gCrea(-1) and 1.9 (range 0-47.8) U gCrea(-1) in group 2 (p < 0.05). Thus, deep hypothermic circulatory arrest (DHCA) subjected the kidney to ischemia reperfusion injury. Although the findings are mild and do not indicate severe ischemic renal damage, potential renal damage by DHCA should be taken into account when planning surgical procedures for congenital heart disease patients with additional risks of acute renal failure.

Hemorheology and renal function during cardiopulmonary bypass in infants.

BACKGROUND: Acute renal failure is an occasional complication after cardiopulmonary bypass in infants. Whereas it is well known that postoperative hemodynamics inflict acute renal failure, the influence of extracorporeal circulation on the kidney is less clear. Moreover, changes in blood viscosity occur during and after surgery, which may influence renal dysfunction. For this reason, we investigated the impact of blood viscosity on renal function during cardiopulmonary bypass. METHODS: In 34 patients weighting less than 10 kg, we performed repeated analysis of urine, blood, and plasma viscosity. RESULTS: Polyuria and proteinuria that appeared during cardiopulmonary bypass indicated an elevated transglomerular filtration gradient, which recovered within 24 hours. The appearance of N-acetyl-beta-D-glucosaminidase in the urine, and elevated excretion of sodium, were additionally indicative of mild tubular damage. Elevation of blood viscosity during hypothermic perfusion showed a statistical correlation with proteinuria and N-acetyl-beta-D-glucosaminidaseuria. With hypothermia, the relation of blood viscosity to plasma viscosity became stronger, while the relation to the hematocrit decreased compared to normothermia. CONCLUSIONS: During cardiopulmonary bypass perfusion, the kidney can be stressed by proteinuria and mild tubular damage. Our data provide evidence that the kidneys can be protected by improved blood viscosity during cardioplegia, but this needs confirmation in a prospective interventional study.