Ultrasonic measurement of bladder wall thickness and bladder weight in children with lower urinary tract symptoms

Introduction and aim: Children with lower urinary system disfunction (LUSD) may have bladder wall hypertrophy. As a result, functional bladder volume decreases and intravesical pressure increases. LUSD is most common non-neuropathic bladder-sphincter disfuction in children.LUSD with bladder wall trabeculation due to detrussor hypertrophy can be visualised during cystoscopy and cystography. Increase in bladder wall thickness (BWT) due to these alterations in bladder wall can be determined by ultrasonography (US). Thus degree of the pathology can be estimated by US which is a noninvasive method. Also postvoiding residue (PVR) can be measured by US and flowmetry which is an another noninvasive method can be combined PVR, so voiding disfunction can be diagnosed and followed up. There are some recent studies in the literature about measurement of BWT in children with LUTD symptoms by US. Estimation of bladder weight (BW) as well as BWT is reported to be more valuable during diagnosis of LUTD. There is no study in children about this subject.The aim of this study is to determine the differences in BWT and BW in children with LUTD and subtypes. Also to determine which patients can be treated and followed up with US without urodynamic study.Material and method: Between July 2011 ? February 2012 we performed urodynamic study in 15 patients with LUTD symptoms. When we reached the maximum cystometric capacity during the urodynamic study, we stopped filling the bladder and performed bladder US. BWT was measured and BW was estimated.Patients were grouped as with OAB and with DFV. The age matched BW was calculated according to each patient?s age in each group and was compared with the US estimated BW.Data are shown with mean ± standard deviation (mean ± SD). Differences between the groups in the analysis of variance (Kruskal-Wallis) and subsequent post-hoc tests (Mann-Whitney U) were detected. p <0.05 was considered statistically significant.Results: The mean age of 15 patients was 8,0 ± 1,5 years (5-11 years). DFV was found in 6 patients (6 girls) and OAB in 9 patients (8 girls, 1boy). UTI was determined in 8 patients, VUR in 5 patients, double collecting system in 1 patient, labial synechiae in 1 patient. One patient has a history of acute poststreptococcal glomerulonephritis.V, BWT and BW were compared according to the diagnosis of urodynamics. According to the groups, the bladder V were 218,00 ± 86,55 ml in DFV group and 208,44 ± 73,87 ml in OAB group, BWT were 2,48 ± 0,83 mm in DFV group and 2,21 ± 0,70 mm in OAB group, BW were 50,66 ± 18,60 gr in DFV group and 45,66 ± 9,89 gr in OAB group. The age matched BW were 14,06 ± 1,77 gr in DFV group and 13,64 ± 1,10 gr in OAB group.The percent deviation from age matched BW was calculated according to this formula: ((USG estimated BW - age matched BW) / age matched BW) x 100. The percent deviation were found 114-458 % in DFV group and 132-410 % in OAB group. The USG estimated BW was significantly higher than age matched BW in both groups ( p < 0.05). The percent deviation from age matched BW was over 100% for each patient in both groups.Conclusion: USG estimation of bladder BWT and BW would be a useful tool in initial assessment of LUTD patients. Urodynamics requirement may be decided by estimation of BW and excluding DI with uroflowmetry before a complete urodynamic investigation.