Management of Primary Obstructive Megaureter by Endoscopic High-Pressure Balloon Dilatation. IDEAL Framework Model as a New Tool for Systematic Review

Endoscopic treatment of primary obstructive megaureter with high pressure balloon dilation in infants

INTRODUCTION AND OBJECTIVE

Ureteral reimplantation of the dilated ureter in infants is challenging; however, some patients with primary obstructive megaureter (POM) in this age group require intervention due to clinical or radiological progression. We sought to determine if high pressure balloon dilation (HPBD) can serve as a definitive treatment for POM in children under one year of age, or as a temporizing measure until later reimplantation.

MATERIALS AND METHODS

All patients from a single institution who underwent HPBD between October 2009 and May 2022 were retrospectively reviewed. Patients were excluded if older than 12 months or diagnosed with neurogenic bladder, posterior urethral valves, or obstructed refluxing megaureter. Patients with prior surgical intervention at the ureterovesical junction were excluded. Indications for surgery included progressive hydroureteronephrosis or urinary tract infection (UTI). Balloon dilation was performed via cystoscopy with fluoroscopic guidance, followed by placement of two temporary ureteral stents. Primary outcomes were improvement or resolution of megaureter and rates of subsequent reimplantation. Secondary outcomes included total number of anesthetics and postoperative UTIs.

RESULTS

Fifteen infants with median age of 7.6 months (IQR 3.8-9.7) underwent HPBD. Twelve (80%) patients were detected prenatally and 3 (20%) after a UTI. Indication for surgery was progressive hydroureteronephrosis in 10 patients (67%) and UTI in five (33%). All had SFU grade 3 or 4 hydronephrosis on preoperative ultrasound and median distal ureteral diameter was 13 mm. Median follow up was 2.9 years. Twelve (80%) succeeded with endoscopic treatment: 7 patients had an undetectable distal ureter on ultrasound at last follow-up, 5 were improved with median distal ureteral diameter of 7 mm. Three patients (20%) required ureteral reimplantation due to progressive dilation, all with grade 4 hydronephrosis and distal ureteral diameters were 11, 15, and 21 mm. Six patients (40%) required two anesthetics to complete endoscopic treatment. Among those, 4 patients required initial stent placement for passive dilation followed by a second anesthetic for HPBD weeks later. Two patients underwent repeat HPBD following postoperative proximal migration of the ureteral stents. All 15 patients had an additional anesthetic for removal of stents. Five patients (33%) were treated for a symptomatic UTI (4 febrile, 1 afebrile) with the stents indwelling but there were no UTIs in the group following stent removal.

CONCLUSION

Balloon dilation is a practical option for treatment of POM in infants, and in most cases (80%) avoids subsequent open surgery (over median 2.9 years of follow-up).

Endoscopic balloon dilation of primary obstructive megaureter: is fluoroscopic guidance necessary?

OBJECTIVE

To compare the long-term effectiveness, complications, and outcomes of primary obstructive megaureter (POM) treated by endoscopic balloon dilation under fluoroscopic guidance versus not using radioscopy during the procedure.

PATIENTS AND METHODS

A comparative study between POM cases treated at our institution by endoscopic balloon dilation (EBD) under fluoroscopic guidance (FG) (n = 43) vs no fluoroscopic guidance (NFG) (n = 48) between the years 2004 and 2018 was conducted. The procedure in FG consisted of performing a retrograde pyelography before dilation. Then, a guidewire is introduced to the renal pelvis, and the dilation of the vesicoureteral junction is performed using high-pressure balloon catheters under fluoroscopic vision. Finally, a double-J stent is placed between the renal pelvis and bladder. The procedure in NFG was performed exclusively under cystoscopic vision without radiological exposure. Complications, outcomes, and success rates were analyzed using Spearman's correlation test. Mean follow-up was 12.5 ± 2.2 years in FG and 6.4 ± 1.3 years in NFG.

RESULTS

MAG-3 showed significant differences in renal drainage before and after endoscopic treatment in both groups (p < 0.001 T-test). Statistical analysis did not reveal differences between groups in initial technical failure (r: - 0.035, p = 0.74), early postoperative complications (r: - 0.029, p = 0.79), secondary VUR (r: 0.033, p = 0.76), re-stenosis (r: 0.022, p = 0.84), long-term ureteral reimplantation (r: 0.065, p = 0.55), and final outcome (r: - 0.054, p = 0.61). The endoscopic approach of POM had a long-term success rate of 86.5% in FG VS 89.6% in NFG.

CONCLUSIONS

Endoscopic balloon dilation of POM can be done with no radiation exposure with similar results, effectiveness, and outcomes.

Laparoscopic nipple invagination combined extravesical (NICE) reimplantation technique in the management of primary obstructed megaureter

AIMS

Villanueva challenged Paquin's 5:1 tunnel length and showed in a computer simulation model that UVJ competence was more sensitive to a 2-mm protrusion of ureteric orifice into the bladder compared to an increase in the intravesical tunnel. Thompson later successfully applied the Shanfield technique of invaginating the spatulated primary obstructed megaureter (POM) laparoscopically, causing a nipple antireflux mechanism. In this study we have reported the outcomes of our modification: Nipple Invagination Combined Extravesical (NICE) reimplantation, in the management of POM.

METHODS

Patients with POM who underwent NICE reimplantation (summary figure) were followed up and outcomes were analysed. There were three modifications in this compared to Shanfield technique: 1. Detrusor myotomy was performed before opening the bladder mucosa. The detrusor edges were closed later over the invaginated ureter as an extravesical reimplantation. 2. The ureter was held invaginated inside the bladder mucosal opening by two sutures at 6 & 12 O' clock positions instead of a single suture, 3. The dilated ureter was not spatulated inferiorly, as it automatically opens out later inside the bladder to form a nipple.

RESULTS

Eleven patients underwent laparoscopic NICE reimplantation; median age: 6 months (5-24); demographics (R: L = 5:6; M:F = 7:4). The mean duration of surgery was 133 min (110-180) and the mean length of hospital stay was 3.6 days (3-5). There were no immediate post-operative complications in the form of leak in any patient. The median follow-up duration was 20 months (18-29). DRF improved in 7 patients while in 4 it remained static; no patient had deterioration. On follow-up VCUG, none had vesico-ureteric reflux (VUR). The nipple effect could be noticed later at follow-up ultrasonograms and at cystoscopy during stent removal.

DISCUSSION

Paquin emphasised on 5:1 ureteral re-implant tunnel length while Lyon felt that the shape of the ureteral orifice was more important. Shanfield introduced a technique of creating a nipple valve effect by invaginating the ureter intravesically. However it was held by a single suture and had no detrusor backing. NICE reimpantation incorporates a short extra vesical reimplant to the Shanfield technique and literally eliminates post-operative VUR. It is simple and could easily be performed laparoscopically even in small infant bladders. The ureteric orifice kept in line enables future upper-tract access. Our preliminary data suggests that the NICE reimplantation for POM is very successful. Limitations are small numbers and short follow-up. Further larger studies are warranted to authenticate this novel technique.

Endoscopic balloon dilatation for the treatment of primary obstructive megaureter <24 months of age: Does the size of the balloon influence results?

INTRODUCTION

Endoscopic balloon dilatation (EBD) can be performed with different catheters and its durability is still controversial. This study aimed to compare long-term results of EBD performed <24 months of age using balloons of 4 mm vs. 6 mm in diameter.

MATERIALS AND METHODS

Retrospective study of consecutive patients with unilateral primary obstructive megaureter (POM) undergoing EBD <24 months of age by two surgeons from 01/2009 to 12/2020. The technique was consistent, but for balloon diameter, which was 4 mm in group A vs. 6 mm in group B. End-points included peri-operative complications, success rate (improving dilatation and non-obstructive drainage on 9-month scintigraphy), and long-term outcome (need for reimplantation and diameter of retrovesical ureter at last ultrasound).

RESULTS

The procedure was completed in all planned patient. Group A included 15 patients and Group B 30 patients. Groups were not significantly different for age (p < 0.09), gender (p < 0.1), laterality (p < 0.7), and preoperative median ureteral diameter (p = 0.08). No perioperative complications occurred. Four group A patients required a cutting balloon to achieve a satisfactory dilatation of the vesicoureteral junction (p = 0.009). After a median (range) follow-up of 70 (19-155) months, success rate was 73.3% vs. 83.3% (p = 0.45), 4/15 group A and 5/30 group B patients required reimplantation within 2 years of EBD. In successful cases, median (range) ureteral diameter at last follow-up was 6 (0-17) mm vs. 5 (0-14) mm, which was significantly better than preoperative value (p = 0.003 and p < 0.001, respectively), but not significantly different (p = 0.8) between groups.

DISCUSSION

EBD is an umbrella term that encompasses many technical variations, which can be key for success. Although limited by the small numbers and the comparison of patients treated over two subsequent periods, this is the first study focusing on the role of balloon size.

CONCLUSIONS

The diameter of the balloon did not influence significantly long-term results, but the 6 mm balloon slightly increased the success rate of EBD to 83.3% and eliminated the need for cutting balloons to achieve a satisfactory dilatation.

Endoscopic treatment of obstructive ureterohydronephrosis in children

Obstructive ureterohydronephrosis in childhood population is a matter of debate between paediatric surgeons and paediatricians, as far as the therapeutic protocol that should be applied. Close observation, chemoprophylaxis, endoscopic and surgical approaches are the universally used techniques that provide quality of life in the paediatric patients. Undoubtedly, “the less is more” even when we have to encounter obstructive ureterohydronephrosis in children. Herein, we present a short case series where the endoscopic management of obstructive uropathies proved to be therapeutic without any need of surgical intervention.