Clinical and experimental study of ureterovesical junction reflux

Five children with seven congenital ureterovesical junction obstructions with unilateral or bilateral hydroureter, hydronephrosis and severe renal damage were studied. Routine therapeutic procedure was applied in all cases, i. e. ureterocutaneostomy (Sober and Williams method) in order to achieve drainage, restore renal function and decrease dilatation of ureters. Ablatio of valves was performed in all cases of posterior urethral valves. A combined technique of ureterovesicomanometry was applied as a measuring procedure (Through ureterocutaneostomies). Dynamics of the pressure change was utilised in different parts of the submucosal ureters and bladder, as well as control of the colour appearance after injection of colour into the bladder to evaluate vesicoureteral junction function.
Keywords: VESICO-URETERAL REFLUX - physiopathology; URODYNAMICS; URETER - physiopathology; BLADDER - physiopathology
Urine boluses are transported across the ureterovesical junction (UVI) by ureteral peristalsis which is developed by the trilaminar muscular layer of the UVI ureter segment (1). Such peristalsis is represented by fast peristaltic presure waves of the ureterovesical perfusion curve (1). Various clinical parameters were used to evaluate the UVI in the patients with vesicoureteral reflux. These included cystoscopic assesment of the configuration and location of the ureteral orifice (2) and determination of the length of the intravesical tunnel by means of ureteral catheter (3).
In this study, by perfusing the catheter used for determining tunnel length with a perfusion rate of 10 ml/min and by measuring intravesical and intraureteral pressures, we obtained information concerning alterations in function associated with vesicoureteral reflux.
Tests were performed on 7 congenital vesicoureteral junctions in five children (between 3 and 5 years of age) who had the most severe stage of ureterohydronephrosis and substantial renal damage. These children either had posterior urethral valves or megacystis-megaureter syndrome.
Routine therapeutic procedure was performed in all patients, i. e. ureterocutaneostomy (Williams or Sober method), as the first step (4, 5) and ablate of valves in all children with posterior urethral valves, as the second step. In the period between six months to two years after surgical treatment, an anti-reflux operation was planned if regression of vesicoureteral reflux had not appeared. Due to the fact that all tests were done before the possible anti-reflux operation and due to the age of the children, all procedures were free of anesthesia (the procedure itself is not painful). Urodynamic tests were combined with technique of vesicometry and ureterometry through ureterocutaneostomy. Cystometry is a standard physiological examination method utilized for qualitative and quantitative analysis of detrusor urine function. Through cystometry it is possible to measure pressure in the bladder during the phase of filling up with urine and during miction (6). This method provides information about the characteristics of the walls of the bladder, force of contraction of muscles detrusor urine, as well as resistance during miction, and inervation of the bladder.
Measuring of intraureteral pressure serves for differential diagnosis of unexplained failure of urine transport. This kind of measuring was standardized after the introduction of the electric manometer. The principle is the same as in cystometry, with the exception that the catheter is placed into the lumen of the ureter ways either through the bladder, percutaneously by ureterostomy, or with percutaneous (ultrasonic) punction of the renal pelvis (6).
Pressure was measured using a piezoelectric transformer, an electric amplifier and oscilloscope. The electric manometer ured for pressure measuring was made by Hewlett-Packard. It contains a membranous piezoelectric transformer of 1290 A whose sensitivity is 40 mV/mm Hg. The transformer was connected to the amplifier 78205 D and oscilloscope 78304 A 0-100 and 0-300 mm Hg.
While the child was in a lying position, a Foley catheter Ch 8 was inserted into the bladder, zero point was gauged and the catheter was connected to the electric manometer (Hewlet-Pakard) to measure the pressure. The bladder was filled continuously 10 ml/min with isotonic saline fluid (at 37oC) coloured with indigocarmin.
The next procedure was to insert prothesis (Ch 6) graduated for every l cm of its length through ureterocutaneostomy to ureter and through vesicoureteral junction (UVI) to the bladder. The zero point was gauged again and prothesis connected to the electric manometer using perfusion drain and Y-adapter. Therefore, it was possible to measure intra-ureteral and intra-vesicular pressure simultaneously. It was possible to confirm that the ureteral catheter was placed in the bladder in the following ways: to monitor the appearance of the indigocarmin colour at ureteral catheter, to observe the level of pressure in the ureter and bladder (which had to be same), and by x-ray. By moving the ureteral catheter gradually by 1 cm and by measuring the pressure in the empty and full bladder (with aspiration of liquid from the catheter), the analysis of congenital ureterovesical junction was possible.
Tables 1 and 2 present the results of the measuring procedures. The increase of pressure at ureterovesical junction was - when the bladder was empty - on average 6.64 cm H2O, and - when the bladder was full - 14.67 cm H2O between the ureterovesical junction and the bladder was recorded for five ureters (Table 1 and 2)., The highest increase in pressure was found 1 cm from the end of ureter near the bladder base, i. e. in the intravesical portion of the ureter. When the catheter was placed deeper into the ureter the pressure gradually decreased and equalized with the pressure in the ureter.
In two cases (ureter # 1 and # 7) the reflux of the colour (indigocarmin) on ureterocutaneostomy was observed. In the aforementioned cases an increase of pressure at the ureterovesical junction was not recorded; on the contrary, the intraureteral and intravesical pressure were the equal.
Category: Case report
Volume: Vol. 43, No 1, january - march 1999
Authors: B. Župančić, I. Bradić, V. Župančić, A. Antabak, Lj. Popović, M. Majerović, J. Turčić
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