Hydronephrosis clinical trials

Ambulatory Blood Pressure Measurement in Children With Congenital Urine Flow Obstruction

PURPOSE - HYPOTHESIS: Children with unilateral congenital urine flow impairment, who require surgery, have abnormal 24-hour ambulatory blood pressure measurements. OBJECTIVES: To Measure 24-hour ambulatory blood pressure in children who have unilateral hydronephrosis or multicystic-dysplastic kidneys. To compare these blood pressure measurements between the children who require surgical correction and those who do not need surgical correction. BACKGROUND: With the introduction of ultrasound examinations of pregnant women, previously undetected abnormalities in the fetus are being detected. Dilatation of the kidney caused by congenital unilateral impairment to the urine flow either partial, presenting as unilateral hydronephrosis or complete, as seen in children with multicystic-dysplastic kidneys, id a common finding affecting approximately 1: 1,500 pregnancies (Cendron et al 1994). The majority of infants do not require surgery, with only 25% needing surgery by 18 months of age (Ransley 1991). However, i8n a few. There is an increase in renal dilatation which ultimately results in a reduction in renal function. The decision to operate is dependent on changes in renal pelvic diameter observed on serial ultrasound scans and on renal function. This process is often lengthy an requ8ires numerous scans, which can be upsetting for parents and child. M<any techniques have been used to identify, early, those patients who will require surgery. These have included: Intra-0renal pressure measurements, renal function, and calyceal diameter (Feung L 1997). To date, none have shown to be better than ultrasound (Dhillion HK 1998). Ambulatory blood pressure monitoring measures the blood pressure multiple times during a predefined period. It, therefore, more accurately reflects the continuous nature of blood pressure during both awake and sleep periods (Sorof JM 2001). Consequently, it may detect abnormalities in blood pressure that are missed on a single reading. This has been shown in the one previous study investigating ambulatory blood pressure and patient with multicystic dysplastic kidneys (Seeman T et al Eur J Pediatr 2001). In this study, 20% of the children studied had abnormal results when ambulatory blood pressure was monitored.