A MODIFIED TECHNIQUE OF URETEROPLASTY FOR MEGAURETER IN CHILDREN

Advancements in Surgical Management of Megaureters

PURPOSE OF REVIEW

To review and describe the recent evolution of surgery for the various types of pediatric megaureter.

RECENT FINDINGS

Megaureter management first relies on determining the underlying cause, whether by obstruction, reflux, or a combination, and then setting appropriate surgical indications because many cases do not require surgery as shown by observation studies. Endoscopic balloon dilation has been on the rise as a major treatment option for obstructive megaureter, while refluxing megaureters can also be treated by laparoscopic and robotic techniques, whether extravesically or transvesicoscopically. During ureteral reimplantation, tapering is sometimes necessary to address the enlarged ureter, but there are also considerations for not tapering or for tapering alternatives. Endoscopic and minimally invasive surgeries for megaureter have been the predominant focus of recent megaureter literature. These techniques still need collaborative prospective studies to better define which surgeries are best for patients needing megaureter interventions.

Endoscopic dilatation/incision of primary obstructive megaureter. A systematic review. On behalf of the EAU paediatric urology guidelines panel

INTRODUCTION

Historically, ureteral reimplantation (UR) has been the gold standard for treatment of primary obstructive megaureter (POM) with declining renal function, worsening obstruction, or recurrent urinary tract infections. In infants, open surgery with reimplantation of a grossly dilated ureter into a small bladder, can be technically challenging with significant morbidity. Therefore, less invasive endoscopic management such as dilatation or incision of the ureter-vesical junction, has emerged as an alternative to reimplantation during the last decades.

OBJECTIVE

To systematically evaluate the effectivity, safety, and potential benefits of endoscopic treatment (dilatation with or without balloon or incision) of POM in comparison to UR.

STUDY DESIGN

A systematic review was conducted. Randomized controlled trials (RCTs), nonrandomized comparative studies (NRSs), and single-arm case series including a minimum of 20 participants and a mean follow-up more than 12 months were eligible for inclusion.

RESULTS

Of 504 articles identified, 8 articles including 338 patients were eligible for inclusion (0 RCTs, 1 NRSs, and 7 case series). Age at time of surgery was minimum 15 days to a maximum of 192 months. Indications for endoscopic treatment (ET) included patients with loss of split renal function (>10%) and worsening of hydroureteronephrosis. The studies analysed reported a success rate ranging from 35% to 97%. Success was defined as stabilization of differential renal function without further procedures. A post-operative complication rate of 23-60% was reported (mostly transient haematuria, urinary tract infections and stent migration or intolerance). In 14% of the cases salvage UR following initial ET, was performed due to relapse of symptomatic POM.

CONCLUSION

Endoscopic treatment for persistent or progressive POM in children is a minimally invasive alternative to UR with a long-term modest success rate. Additionally, it can be performed within a wide age span, with equal success rate and complication rates.

High-pressure balloon dilatation of primary obstructive megaureter in children: a systematic review

OBJECTIVE

We aimed to evaluate the effectiveness and complication rates of endoscopic high-pressure balloon dilatation (HPBD) in treating primary obstructive megaureter (POM) in children based on current literature. Specifically, we wanted to clarify the evidence on the use of HPBD in children under one year of age.

METHODS

A systematic search of the literature was performed via several databases. The preferred reporting items for systematic reviews and meta-analyses guidelines were followed. The primary outcomes studied in this systematic review were the effectiveness of HBPD in relieving obstruction and reducing hydroureteronephrosis in children. The secondary outcome was to study the complication rate of endoscopic high-pressure balloon dilatation. Studies that reported one or both of these outcomes (n = 13) were considered eligible for inclusion in this review.

RESULTS

HPBD significantly decreased both ureteral diameter (15.8 mm [range 2-30] to 8.0 mm [0-30], p = 0.00009) and anteroposterior diameter of renal pelvis (16.7 mm [0-46] to 9.7 mm [0-36], p = 0.00107). The success rate was 71% after one HPBD and 79% after two HPBD. The median follow-up time was 3.6 years (interquartile range 2.2-6.4 years). A complication rate of 33% was observed, but no Clavien-Dindo grade IV-V complications were reported. Postoperative infections and VUR were detected in 12% and 7.8% of cases, respectively. For children under one year of age, outcomes of HPBD seem to be similar to those in older children.

CONCLUSIONS

This study indicates that HPBD appears to be safe and can be used as the first-line treatment for symptomatic POM. Further comparative studies are needed addressing the effect of treatment in infants, and also long-term outcomes of the treatment. Due to the nature of POM, identifying those patients who will benefit from HPBD remains challenging.

'Mini' extravesical reimplant with 'mini' tapering for infants younger than 6 months

INTRODUCTION

Some infants with obstructed megaureters or ectopic ureters requiring surgery undergo a cutaneous ureterostomy followed by definitive repair after 12 months of age. Since 2013, a 'mini' extravesical reimplant with or without 'mini' tapering (MER) was performed instead of cutaneous ureterostomy in such infants.

OBJECTIVE

To describe the technique and outcomes for MER.

STUDY DESIGN

This is a retrospective review of infants younger than 6 months who underwent MER. MER consists of a 2- to 3-cm extravesical tunnel, regardless of the ureter diameter. 'Mini' tapering consisted of an adventitial sparing technique involving only the distal 2-3 cm of the ureter. Details of the technique are included in the video. The main outcomes were postoperative symptomatic urinary tract infections (UTI's) and reoperations. Voiding function was assessed at the last contact with the family.

RESULTS

Nine consecutive infants underwent MER from July 2013 to March 2018. Four patients had ectopic ureters and five had primary obstructed megaureters. The median ureteral diameter was 1.5 cm. Indications for surgery were as per the British Association of Pediatric Urologists guidelines on megaureters. All patients had 3-month postoperative renal ultrasound, and seven of the nine patients had postoperative voiding cystourethrogram (VCUG). One patient with a normal postoperative VCUG and MAG 3, as well as resolved hydroureteronephrosis had a few postoperative febrile UTIs but no more for >1 year at the last follow-up. At a median time from surgery of 44 months, there have been no reoperations (except cystoscopy with stent removal). With regard to voiding function, six patients were successfully potty trained, one has bowel and bladder incontinence at the age of 4 years - with stable renal ulstraound -, and two are younger than 2 years.

DISCUSSION

MER has been the only surgery needed for the cohort of nine infants younger than 6 months with distal ureteral obstruction at a median time from surgery of 44 months. Voiding function does not appear to be affected by the operation.

CONCLUSIONS

For babies younger than 6 months of age in need of surgery for obstructed distal ureter, MER appears to be a feasible and effective option, associated with reduced morbidity and reoperation rate compared to the alternatives.

Endoscopic Management of Primary Obstructive Megaureter: A Systematic Review

BACKGROUND

The gold standard treatment for primary obstructive megaureter (POM) with declining renal function, worsening obstruction, or recurrent infections is ureteral reimplantation with or without tapering. In infants, open surgery can be technically demanding and associated with significant morbidity. We conducted a systematic review of the literature with special interest in endoscopic management of POM and its outcomes.

MATERIALS AND METHODS

A search was conducted of the MEDLINE/Ovid, PubMed, Embase, and Web of Science databases. Only full-text articles written in the English language and involving greater than one reported pediatric case per publication were included. Two authors independently extracted data and assessed strength of evidence for each study.

RESULTS

We found 11 retrospective and 1 prospective, single institution case series that met selection criteria, describing 222 patients with 237 obstructed renal units. Mean age at time of surgery was 24.6 months. The most common endoscopic approaches were cystoscopy+high-pressure balloon dilation+Double-J ureteral stent placement (49.5%), cystoscopy+incisional ureterotomy+Double-J ureteral stent placement (27.8%), and cystoscopy+Double-J ureteral stent placement (18.9%). For all approaches and age groups, anatomic and functional success rates were 79.3% (146/184) and 76.7% (132/172), respectively. Anatomic success rates were highest in children ≥12 months of age (82.3%, 117/142). Endoscopic retreatment was performed in 15.1% of cases with a 36.7% overall surgical reintervention rate. Forty-one ureters progressed to ureteral reimplantation. Complications were generally mild (Clavien-Dindo Grades I-II), but 12 ureters did develop vesicoureteral reflux. Mean follow-up period was 3.2 years.

CONCLUSIONS

Endoscopic management for persistent or progressive POM in children ≥12 months of age is a minimally invasive alternative to ureteral reimplantation with modest success rates. In infants, it may best be utilized as a temporizing procedure. Approximately one-third of patients require surgical reintervention.

Endoscopic balloon dilatation in primary obstructive megaureter: Long-term results

BACKGROUND

Open neoureterocystostomy is the traditional surgical treatment for primary obstructive megaureter (POM). Endoscopic balloon dilation is a new minimally invasive alternative. It has been shown to be a safe and effective endoscopic procedure over short-term follow-up; however, few studies have shown its long-term efficacy.

OBJECTIVE

The aim of this study was to evaluate the long-term results and complications of balloon dilation for the treatment of primary obstructive megaureter in infants.

MATERIALS AND METHOD

A retrospective review was performed of patients with primary obstructive megaureter treated with balloon dilation. The diagnosis was made through ultrasonography, diuretic isotopic renogram, and voiding cystourethrogram (VCUG). The indications for surgery were: worsening hydronephrosis, renal function impairment, and recurrent urinary tract infections (UTI). All patients were followed 3 months after the endoscopic procedure with ultrasonography and MAG-3 renogram, and 6 months after surgery with VCUG and ultrasonography. Annual ultrasound and clinical follow-up were performed until present time.

RESULTS

Seven boys and six girls were treated (median age 9 months, range 2-24). Ten patients had a prenatal diagnosis of hydronephrosis, and the diagnoses was made after UTI in three patients. No intraoperative complications were observed. One double-J stent was replaced after endoscopic procedure for malpositioning, and four patients developed UTIs after surgery. All patients had non-obstructive MAG-3 diuretic renogram 6 months after surgery. The mean washout on the renogram and the ultrasound pelvic diameter showed pre-operative and postoperative statistical differences (Summary Table). All patients maintained their results without recurrence or any other complications in the long-term follow-up. The median follow-up was 10.3 years (range 4.7-12.2).

DISCUSION

In 2014, Aparicio et al. first described balloon dilation being used as a definitive treatment for primary obstructive megaureter in infants. Bujons et al. also presented 20 cases with a mean follow-up of 6.9 years. The current study is the largest to date, with a median follow-up of 10.2 years. It demonstrated the value of balloon dilation as a definitive treatment for POM. Despite these results, it was difficult to establish endoscopic balloon dilation as a definitive treatment for POM, due to the absence of long-term studies like the current one.

CONCLUSION

Balloon dilation can be a safe and effective endoscopic procedure for the treatment of primary obstructive megaureter in infants, and has shown good outcomes in long-term follow-up. More studies are needed to demonstrate these results.

Extracorporeal ureteral tailoring during HIDES laparoscopic robotic-assisted ureteral reimplantation for megaureter

INTRODUCTION

Although laparoscopic robotic-assisted intracorporeal ureteral tailoring is feasible and several authors have reported doing it, it adds a level of complexity to the surgery that many robotic surgeons are uncomfortable with. Also, some techniques for tailoring the ureter, like the one described by Ossandon, would be very difficult to perform intracorporeally or violate principles of hidden incision endoscopic surgery (HIDES) by adding extra ports in visible locations.

MATERIAL AND METHODS

Extracorporeal ureteral tapering is performed by extracting the ureter through a 10-mm step trocar placed in the midline at the level of the biking line. Once the ureter is tapered and a stent has been secured, the 10-mm trocar is replaced and the rest of the reimplant is performed in a way very similar to when performing a robotic apendicovesicostomy.

DISCUSSION

Extracorporeal ureteral tailoring can be added to the bag of tricks that robotic surgeons can resort to when faced with the situation of a dilated ureter without compromising cosmesis.

Result of endoureterotomy in the management of primary obstructive megaureter in the first year of life: preliminary report

PURPOSE

The present study aimed to investigate the efficacy of endoureterotomy in patients who were less than 1-year-old with primary obstructive megaureter (POMU).

PATIENTS AND METHODS

Three of 10 patients with POMU aged between 2 and 12 months for whom conservative management was not applicable had recurrent urinary tract infection (UTI) and urosepsis, while the rest had decreased renal function. After obtaining the clinical history and performing physical examinations and imaging studies (ultrasonography, voiding cystourethrography (VCUG), radionuclide renal scan), the patients underwent endoureterotomy using a neonatal ureteroscope (4.5F) and Bugbee electrode with pure cutting current at the 6 o'clock position. A Double-J stent was inserted and removed 1 week later. This was followed by serial physical examination, renal function test, urine analysis, urine culture, and imaging studies in the 1st month and every 3 months after Double-J stent removal.

RESULTS

Hydroureteronephrosis was significantly decreased in nine patients. Postoperative VCUG revealed no sign of iatrogenic vesicoureteral reflux. In addition, a follow-up renal scan showed remarkable improvement in the renal function in the patients who had decreased renal function, except for one patient in whom uncontrolled urosepsis developed in the follow-up; the patient underwent cutaneous ureterostomy. No UTI was detected in the group who presented with recurrent UTI and urosepsis.

CONCLUSION

According to the results of our study, endoureterotomy may be an alternative in management of POMU. Of course, further studies with longer follow-up periods are needed to confirm the applicability of this method in patients younger than 1 year.

Concomitant endoureterotomy and dextranomer/hyaluronic acid subureteral injection for management of obstructive refluxing megaureter

PURPOSE

To present the results of our experience with combined endoureterotomy and endoscopic injection of dextranomer/hyaluronic acid (Deflux) for the treatment of primary obstructive refluxing megaureter (PORM).

PATIENTS AND METHODS

Eighteen children (12 female, 6 male; mean age-14 months) with 20 PORM units underwent concomitant endoureterotomy and endoscopic subureteral Deflux injection. All patients underwent endoureterotomy at the 6-o'clock position with insertion of a 3F Double-J ureteral stent into the obstructed segment of ureter and subureteral injection of Deflux at the 5-o'clock and 7-o'clock positions. The Double-J stent was left in place with its distal tip fixed with a single knot to the external genitalia for easy removal after 1 week. Patients with refluxing nonobstructive ureter on the contralateral side of the PORM unit (seven children) underwent simultaneous endoscopic subureteral injection of Deflux. Voiding cystourethrography (VCUG) was performed at 6 months, and ultrasonography was performed at 1 week 3, 6, and 12 months postoperatively.

RESULTS

With a mean follow-up of 30 months, the procedure was uneventful in all patients. Follow-up VCUG showed no evidence of reflux in 15 ureterorenal (75%), significant decrease in reflux grade in 2 (10%), and no change in 3 (15%) in the endoscopic treated PORM units. No evidence of reflux was observed in the treated contralateral refluxing nonobstructive ureters. Ultrasonography revealed no ureterovesical junction obstruction. In 19 ureterorenal (95%) units, there was a complete resolution or decrease in hydroureteronephrosis.

CONCLUSIONS

The results of this study demonstrate that combined endoureterotomy and subureteral injection of Deflux is safe and effective in the treatment of PORM in selected patients.

Endoureterotomy for Treatment of Primary Obstructive Megaureter in Children

PURPOSE

To describe a new approach to the treatment of primary obstructive megaureter (POMU) using endoscopic endoureterotomy. The results obtained with this technique are reviewed with long-term follow-up.

PATIENTS AND METHODS

A total of 47 children (mean age 3.7 years) with 52 POMU units and a history of failed conservative management underwent endoureterotomy of obstructed juxtavesical and intramural ureter. A 3F Double-J ureteral stent was introduced up to the obstructed segment of ureter. Then a zebra catheter was inserted into the affected ureter beside the stent, followed by a neonatal-size ureteroscope. Following delineation of the length of the narrowed portion of the ureter, a guidewire with a plastic sheath replaced the zebra catheter. A longitudinal incision was made through the detrusor muscle at the 6 o'clock position, leaving the bladder adventitia untouched. The Double-J stent was left in place, while its distal tip was fixed by long nylon suture and single knot to the external genitalia to permit easy removal 1 week after the procedure.

RESULTS

With a mean follow-up of 39 months (range 14-62 months), no leakage, ureteral-orifice obstruction, or reflux was observed. The postoperative success rate was 90% (47 of 52 ureters), defined as resolution or decrease in hydroureteronephrosis and improvement or stability of renal function determined by renal scan. In 37 ureterorenal units (71%), there was complete resolution of hydroureteronephrosis.

CONCLUSIONS

On the basis of previous studies demonstrating the value of endoureterotomy with stenting for the treatment of benign ureteral strictures in adults, we developed a modified endoscopic approach for the treatment of POMU and applied this technique in meticulously selected cases. Our results showed that this approach is a valid option for the treatment of children with POMU.

End Cutaneous Ureterostomy for the Management of Severe Hydronephrosis

PURPOSE

Although rarely indicated, surgical treatment of severe megaureter can pose a formidable technical challenge, especially in the small infant. We present our experience and outcomes with end cutaneous ureterostomy as a temporizing adjunct to future ureteral reimplantation.

MATERIALS AND METHODS

We performed a retrospective cohort study of patients who underwent end cutaneous ureterostomy between 1993 and 2005. Patient demographics, surgical details and outcomes were recorded.

RESULTS

A total of 29 patients (22 males, 7 females) underwent diversion of 34 renal units. Primary megaureter was diagnosed in 15 patients (17 renal units). Secondary megaureter was found in 10 patients (12 renal units). Postoperative megaureter was diagnosed in 4 patients (5 renal units). Mean patient age at time of diversion was 3.2 months for those with primary megaureter and 1.4 years overall. Bilateral diversion or diversion of a solitary functioning kidney was performed in 14 patients (48%), of whom 4 had renal insufficiency. Nine patients (31%) had a febrile urinary tract infection while awaiting undiversion, with no evidence of renal scarring on followup. Undiversion was performed in 12 patients (13 renal units) with primary megaureter at a mean age of 18 months. Overall, undiversion was performed in 21 patients (23 renal units), and ureteral tailoring was required in only 5 renal units (22%). Mean followup after undiversion was 4.2 years for primary megaureter and 3.9 years overall.

CONCLUSIONS

End cutaneous ureterostomy is a safe and effective procedure to temporize massive hydronephrosis while awaiting definitive ureteral reimplantation.