RESUMO
This study was undertaken to determine variations in the amount of glycosaminoglycans [GAGs] excreted by patients with refractory primary nocturnal enuresis [RPNE], and assessment of associated bladder dysfunction with the use of a special ultrasound [US] protocol, as prediction of pathophysiology of refractory primary nocturnal enuresis and associated bladder dysfunction. The study included 30 children with [RPNE] with mean age 7.33 +/- 2.23 and 30 healthy age matched control children with mean age 8.9 +/- 1.68 years. All patients more than 5 years old were treated for primary nocturnal enuresis [PNE] with behavioral therapy and desmopressin for at least 6 months with no response. The studied groups were subjected to the following complete medical history, physical examination, urine analysis and their urinary GAGs excretion was assessed over 24 h using the sodium tetraboratecarbazole method. Plain KUB, and abdominal ultrasound using special protocol was designed for the evaluation of bladder parameters using bladder volume and wall thickness index [BVWI%], and expected percentage bladder volume index for kidney volume. Patients with refractory primary nocturnal enuresis had higher mean values of urinary GAGs excretion than age-matched controls. Also they had low bladder capacity and thick bladder wall more than age-matched. The mean urinary GAGs contents were 38.9, and 27.5 mg/g creatinine in patients with RPNE and controls respectively; [P<0.001]. Comparing the BVWI in normal and enuretic children in correlation with functional bladder capacities we found that patients with low capacity thick bladder wall also have high GAGs excretion. Measuring urinary GAGs excretion and Ultrasound bladder wall thickness can be used as predictive pathophysiological clues, for underlying bladder dysfunction, which has an important role in the pathophysiology of enuresis especially in refractory cases. Also they can minimizing the need for invasive urodynamic study in children with RPNE for assessing bladder wall dysfunction