Primary obstructive megaureter (POM) without vesicoureteral reflux has classically been managed by open surgery with ureteral reimplantation. We present seven patients with POM who were treated endoscopically with balloon dilatation of the distal ureter.
Six boys and one girl with POM were treated from June 2000 through July 2004. Six of the cases were diagnosed prenatally when ectasia of the urinary tract was seen on ultrasound scans. The postnatal diagnosis was also achieved by ultrasonography, along with a diuretic isotopic renogram with MAG-3, intravenous urography, and filling cystography. The age at surgery was 1 to 3 years. In all cases, a compact 10F infant cystoscope with a 5F working channel was used. Dilatation of the stenotic area was performed under fluoroscopic monitoring. A 4F dilating balloon was used, which was insufflated to between 12 and 14 atm for 3 to 5 minutes, and disappearance of the narrowed ring was verified. A Double-J catheter was positioned and withdrawn 2 months after the procedure. Clinical, analytical, and imaging follow-up was carried out with ultrasonography and MAG-3 renography.
The mean follow-up of the patients is 31 months (range 12-56 months). Their clinical progress was highly satisfactory. Five patients exhibited reduced obstruction at MAG-3. One patient needed a second dilatation, and the obstructive curve improved after this additional procedure. One of the patients presented with a febrile urinary infection after the dilatation, but there were no other complications.
Endoscopic management of POM by balloon dilatation has yielded very good results in the short term. Longer follow-up will enable us to determine the final indications for this treatment.
"Congenital megaureter is a term used in many cases of urinary tract dilation detected before and after birth (Shokeir AA et al 2000). In children, the ureteral diameter is usually not >5 mm, and when it is >7 mm, it could be considered a megaureter (Angerri O et al 2007). The studies by Payabvash et al. (Payabvash S et al 2007) and Kajbafzadeh et al. (Kajbafzadeh AM et al 2006) revealed that the proportion of muscular content in the ureteral wall of an obstructed vesicoureteral junction is significantly lower than that in normal specimens. "
[Show abstract][Hide abstract] ABSTRACT: Pacemakers in upper urinary tract (UUT) are still under study.
We reviewed the role of some cells that seem to be involved in the propulsion of urinary bolus from UUT to the bladder.
We focuses on evaluating studies on the mechanisms by which the UUT propels urine to the bladder via pacemaker cells.
Electric active pacemaker cells generate pyeloureteric autorhythmicity driving adjacent smooth muscle cells (SMCs); it emphasizes the role of the interstitial cells of Cajal-like cells (ICC-LCs) localized in the UUT. Interstitial cells of Cajal (ICCs) are now thought to cooperate in conducting and amplifying pacemaker activity in the UUT. These cells produce electrical slow-wave potentials and determine the propagation of peristaltic activity. Identification of ICC-LCs is facilitated by use of c-kit antibodies. Contraction waves arising from the UUT and the propagation of these waves may require the direct involvement of ICC-LCs, as c-kit immunoreactivity appears developmentally at the same time as coordinated unidirectional peristaltic contraction. ICC-LCs observed in the UUT have morphological features similar to those of c-kitpositive ICCs in the gastrointestinal tract. In addition to gastrointestinal motility, ICCs may also play a significant role in the propagation, coordination, and modulation of ureteropelvic peristalsis.
Alterations in ICC-LCs are closely associated with a variety of motility disorders and many congenital urological diseases of the UUT such as primary obstructive megaureter, congenital ureteropelvic junction obstruction, and vesicoureteral reflux.
These observations open the way for further investigations of this cell type. Neurourol. Urodynam. 32: 349–353, 2013.
Aspects of Pacemakers - Functions and Interactions in Cardiac and Non-Cardiac Indications, 04/2013; , ISBN: 978-953-307-616-4
[Show abstract][Hide abstract] ABSTRACT: To evaluate the location of interstitial cells of Cajal-like cells and the ureteral aspect using histopathologic studies of obstructive and refluxing megaureters to reveal the different pathogenesis of megaureters in the human urinary tract. The underlying pathophysiology of obstructive megaureter and refluxing megaureter is poorly understood.
The data from 14 patients with obstructive megaureter (7 boys and 7 girls), with a mean age of 12 months (range 2-84), and 9 patients with refluxing megaureter (7 boys and 2 girls), with a mean age of 11 months (range 4-24), were compared. We investigated the difference in the histopathologic aspects using Masson's trichrome, terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (for apoptosis), and human c-kit antibody (CD117 for interstitial cells of Cajal-like cells) between the obstructive and refluxing megaureters.
The proportion of smooth muscle was significantly lower in segments of refluxing megaureter (32.04% +/- 4.96%) than in the segments of obstructive megaureter (52.48% +/- 3.46%; P < .01). The number of apoptotic cells was significantly increased in the obstructive megaureter (mean 1661 +/- 135.1 cells) compared with the refluxing megaureter (mean 375.2 +/- 65.14 cells; P < .0001). The number of c-kit positive cells was significantly lower in the refluxing megaureter (mean 83.60 +/- 48.84 cells) than in the obstructive megaureter (mean 463.6 +/- 100.4 cells; P < .05).
The differences in the histopathologic aspects can provide information on the possible pathophysiology of obstructive and refluxing megaureters. Ureteral peristalsis can be affected by the increased myocyte apoptosis in the obstructive megaureter and by the decreased number of interstitial cells of Cajal-like cells and smooth muscle content in refluxing megaureters. Additional research is warranted to elucidate the exact pathophysiology.
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