Nephrostomy tube drainage with pyeloplasty: is it necessarily a bad choice?

Comparison between open and minimally invasive pyeloplasty in infants: A systematic review and meta-analysis

INTRODUCTION

Ureteropelvic junction obstruction (UPJO) is the most common cause of congenital hydronephrosis. Techniques such as laparoscopic pyeloplasty (LP) have gained in popularity over recent years. Although some retrospective studies have compared minimally invasive reconstructive techniques with open surgery for treatment of UPJO in infants, results remain controversial due to the small sample size in most of these studies.

OBJECTIVE

To verify whether the benefits of minimally invasive pyeloplasty (MIP) observed in adults and children over 2 years of age also apply to infants.

METHODS

A systematic review of the literature was performed according to PRISMA recommendations. We searched databases of MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials. We excluded studies in which patient cohorts were outside the age range between 1 and 23 months of age (infants). Studies should evaluate at least one of the following outcomes: average hospital stay, operative time, follow-up time, complications, post-surgical catheter use, success rate and reintervention rate. The quality of the evidence was assessed with the ROBINS-I tool.

RESULTS

In total, 13 studies were selected. 3494 patients were included in the meta-analysis, of whom 3054 underwent OP, while the remaining 440 were part of the group undergoing MIP. The mean difference in hospital days was -1.16 lower the MIP group (95 % CI; -1.78, -0.53; p = 0.0003). Also, our analysis showed a significantly shorter surgical time in the group who underwent OP, with a mean operative time of 119.92 min, compared to 137.63 min in the MIP group (95 % CI; -31.76, -6.27; p = 0.003). No statistically significant between-group differences were found respect to follow-up time, complications, post-surgical catheter use, success rate and reintervention rate.

CONCLUSION

This systematic review with meta-analysis has shown that laparoscopic/robotic pyeloplasty in infants is a safe technique with similar success rates to open surgery. Nonetheless, randomized clinical trials with longer follow-up are needed to consolidate these results with more robust scientific evidence.

"Double-Lumen Valve-Controlled Intra-Operative Pyeloplasty Stent (VIPs)": A New Technology for Post-Pyeloplasty Stenting - Proof of Concept Study in a Preclinical Large Animal Model

Background

Pyeloplasty is a common surgical operation with a high success rate. However, significant challenges are to be optimized in the design of stenting systems in order to improve perioperative monitoring of urine drainage and enhance patient and family comfort through easier post-operative care.

Materials and Methods

In a preliminary study in six pigs, handling, mechanical and functional features of this stent system were tested. In our main study, six double-lumen stents (230 mm long each) and 6F/9F external diameter were implanted through the ureteric walls of six domestic pigs to allow postoperative drainage and monitoring following ureteroureterostomy. After a 7-day survival period, monitoring with intravenous antibiotic coverage, and pain control, contrast antegrade pyelogram, under valve control, and renal ultrasonography were conducted and stents explanted and the animals were then euthanized.

Results

The double-lumen valve-controlled stent supported the healing of the neo anastomoses and helped to monitor perioperative urine drainage and perianastomotic leakage accurately. It also guided a well-controlled more informative radiological contrast-supported imaging before removal of the stents that confirmed the healing of the neo anastomotic site and no leak formation. The double-lumen system demonstrated high feasibility regarding its insertion, functionality, and removal capacities. The excellent flexibility of the individual stents allowed exact anatomically controlled implantation.

Conclusion

The double-lumen valve-controlled stent system was studied in a porcine model, which demonstrated its feasibility. Preclinical experience revealed favorable results concerning stent implantation, operability and functionality, in the perioperative management of pyeloplasty or ureteric surgery.

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Pediatric congenital hydronephrosis (ureteropelvic junction obstruction): Medical management guide

The prevalence of asymptomatic hydronephrosis, now detected by ultrasonography, has increased. However, definitive management guidelines for the management of congenital hydronephrosis have not been established. The Japanese Society of Pediatric Urology created a "medical management guide" based on new findings for physicians practicing pediatric urology. We developed a medical management guide focused on congenital hydronephrosis caused by ureteropelvic junction obstruction. This medical management guide consists of the definition, pathophysiology, epidemiology, diagnosis, classification, treatment using a clinical management algorithm of hydronephrosis and the long-term course of the disease. The aim of hydronephrosis management is to determine whether surgery should be carried out to avoid renal dysfunction, as there is a possibility for improvement without intervention. Ultrasonography is essential to make treatment decisions. Management is determined by a comprehensive assessment, including the degree of hydronephrosis, anterior-posterior diameter of the renal pelvis and, if necessary, a nuclear medicine evaluation of the status of urine drainage and renal function.

Retroperitoneal laparoscopic non-dismembered pyeloplasty for uretero-pelvic junction obstruction due to crossing vessels: A matched-paired analysis and review of literature

OBJECTIVE

To compare laparoscopic Anderson-Hynes pyeloplasty (LAHP) and retroperitoneal laparoscopic YV-pyeloplasty (LRYVP) in ureteropelvic junction obstruction (UPJ) in presence of a crossing vessels (CV).

METHODS

Our database showed 380 UPJO-cases,who underwent laparoscopic retroperitoneal surgery during the last 2 decades including 206 non-dismembered LRYVP, 157 dismembered pyeloplasties LAHP, and 17 cases of laparoscopic ureterolysis. Among them 198 cases were suitable for a matched-pair (2:1) analysis comparing laparoscopic retroperitoneal non-dismembered LRYVP (Group 1, n = 131) and dismembered LAHP (Group 2, n = 67) in presence of a crossing vessel. Patients were matched according to age, gender, kidney functions, and obstruction grade. Complications were graded according to modified Clavien-classification.

RESULTS

Comparative data were similar between both groups (LRYVP vs. LAHP) including mean operating time (112 min vs. 114 min), complication rates (4.2% vs. 7.3%) mainly Grade 1-2 according to Clavien classification, and success rates (90% vs. 89%). These results reflected in the reviewed literature indicate that LRYVP provides the advantage of minimal dissection in case of CV with similar outcome. However, redundant pelvis and anteriorly crossing vessels still require a dismembered pyeloplasty LAHP.

CONCLUSION

LRYVP has achieved similar results compared with the previous golden standard of open surgery, especially in case of crossing vessels apart from presence of a redundant pelvis or anteriorly crossing vessel. This can be further improved when using the small access retroperitoneoscopic technique respectively mini-laparoscopy.

A Randomized Control Trial Comparing Outcome after Stented and Nonstented Anderson-Hynes Dismembered Pyeloplasty

Aim

The aim of the study was to compare the efficacy and postoperative complications of stented and nonstented open pediatric dismembered pyeloplasty for ureteropelvic junction (UPJ) obstruction.

Settings and Design

A balanced, parallel group, prospective randomized controlled trial comparing stented and nonstented Anderson-Hynes Dismembered Pyeloplasty.

Subjects and Methods

It included 42 children who required Anderson-Hynes dismembered pyeloplasty for UPJ obstruction (UPJO). Patients were randomized into stented (double "J" [DJ] stent) and nonstented pyeloplasty groups. The intraoperative and postoperative course was compared. Both groups were analyzed for problems such as dysuria, frequency, pain, hematuria and urinary tract infection, and postoperative renal status.

Statistical Analysis

Mann-Whitney U-test, Fisher's exact test, Student's t-tests, and Chi-squared test were used.

Results

Surgical duration was significantly shorter for the nonstented group as compared to the stented group (60.4 ± 6.49 min vs. 78.9 ± 8.17 min). The intraoperative negotiation of DJ stent was troublesome in 21.7% patients belonging to the stented group. The hospital stay was comparable in both groups (4.67 ± 1.9 vs. 4.28 ± 0.67 days). Patients in stented group had experienced dysuria, loin pain, lower abdominal spasmodic pain, and frequency significantly higher than nonstented group. However, the other problems such as fever, hematuria, and urinary tract infections were more common in stented group, but the difference was not statistically significant. There was no difference in resolution of hydronephrosis in both groups.

Conclusions

There is no statistically significant difference in resolution of hydronephrosis following nonstented or stented dismembered pyeloplasty in children with UPJO. However, the patient is more symptomatic due to stent in the postoperative period.

A 5-Fr Externalized Nephroureteral Catheter as the Sole Protective Device for Pediatric Pyeloplasty: The Experiences of 142 Patients

Background

Pyeloplasty for ureteropelvic junction obstruction correction is a common procedure, but the optimal method for protective diversion after pyeloplasty is still a matter of debate.

Objectives

Here, we present our clinical trial experience using a single percutaneous externalized nephroureteral (NU) 5-Fr catheter (infant feeding tube) with multiple side holes as the sole instrument of drainage to provide a protective mechanism.

Materials and Methods

In this prospective study, we analyzed the charts of 142 patients who underwent pyeloplasty from August 2001 through October 2008. We used a single externalized NU 5-Fr catheter with multiple side holes for postoperative upper tract diversion. The catheter was removed in the office after 10 - 14 days. Complications from the use of this catheter, including poor catheter function, premature dislodgement, urinary tract infection, leakage, urinoma, and anastomotic stenosis, were evaluated. The operations were performed by two surgeons at two separate centers.

Results

In all, 148 pyeloplasty procedures were performed on 142 patients. The mean hospital stay length was 2 (1 - 3) days. A contrast study through a catheter demonstrated excellent drainage with no leakage in all patients. Immediately after catheter removal, febrile urinary tract infection and transient obstructive symptoms and signs occurred in 15 patients.

Conclusions

Using a percutaneous externalized NU 5-Fr catheter was sufficient as a protective measure after open pyeloplasty. It costs less than other diverting systems, such as DJ, and can be removed in the office. Therefore, it can be a safe and cost effective procedure, especially in developing countries where cystoscopic set ups are not readily available. There were only a few notable complications.

Is peri-operative urethral catheter drainage enough? The case for stentless pediatric robotic pyeloplasty

BACKGROUND

The necessity for urinary diversion with trans-anastomotic ureteral stenting during pyeloplasty is currently under debate. Performing a stentless repair could eliminate stent-related morbidity, including: stent migration, urinary tract infection, flank pain, and bladder spasms. In addition, there would be no need for a second procedure and associated anesthesia required for stent removal. This study describes the outcomes of robotic-assisted laparoscopic pyeloplasty without use of a ureteral stent.

MATERIALS AND METHODS

An IRB-approved prospective database of all pediatric patients undergoing robotic pyeloplasty from July 2012 to July 2014 at a single institution was reviewed. The 'bypass pyeloplasty' or Anderson-Hynes dismembered pyeloplasty (DP) technique was performed. In both groups, neither a ureteral stent nor an abdominal drainage catheter was utilized. Complications were recorded, including: postoperative pain, bladder spasms, fever, and urinary tract infections. Follow-up renal ultrasound was reviewed for hydronephrosis.

RESULTS

Twenty-seven children (17 male, 10 female) with a mean age of 25 months (range 6-157 months) underwent robotic ureteral stentless pyeloplasty during the study time period. The bypass pyeloplasty technique was performed on 19 children (70%). Mean length of stay was 20.2 hours (range 11-46). No fever, urinary tract infections, or hematuria requiring intervention were experienced. Additionally, there were no reports of bladder spasms or pain requiring pharmacotherapy. The mean follow-up was 8 months (range 4-21). Pre-operative Society of Fetal Urology grading was 3.5 and 3.4 for the dismembered and bypass cohort, respectively, with improvements to 1.1 for both groups at 3 months. Postoperative renal ultrasound hydronephrosis resolved in eight children (29.6%), improved in 14 (51.9%), and was stable in five (18.5%). The overall success rate was 100%.

DISCUSSION

This study was limited by its small cohort and short follow-up, which may not thoroughly describe the efficacy of the stentless repair as it has been shown that stricture and re-obstruction can occur several years after surgery.

CONCLUSIONS

Robotic stentless pyeloplasty is a feasible alternative to conventional methods, with excellent success rates and minimal complications. Importantly, this technique circumvents the need for a second procedure and the associated risks of anesthesia.

Pyeloplasty for hydronephrosis: Issues of double J stent versus nephrostomy tube as drainage technique

Aims:

To compare the efficacy, complications, cost analysis and hospital stay between two methods of drainage of the kidney: double J (DJ) stent versus nephrostomy tube following open pyeloplasty for ureteropelvic junction obstruction hydronephrosis.

Patients and Methods:

This was a prospective randomized study of 20 patients in each group over 14 months. Pre and post-operative (3 months) function and drainage were assessed by ethylenedicysteine scan and intravenous urogram.

Results:

Both groups showed similar good improvement in function and drainage. Nephrostomy group had significantly longer hospital stay (P < 0.001) but incurred less cost. Complications with nephrostomy included tube breakage (n = 1) and urine leak after tube removal (n = 2). DJ stents were associated with stent migration (n = 4), increased frequency of micturition (n = 9), dysuria (n = 4) and urinary tract infection (n = 1).

Conclusion:

Both methods of drainage did not interfere with improvement after pyeloplasty. Minor complications were more with DJ stent (P = 0.0003). Although overall cost of treatment was more with stents, they reduced length of hospital stay. Optimal length of stent is essential to reduce complications secondary to migration and bladder irritation.

Cutaneous pyeloureteral stent for laparoscopic (robot)-assisted pyeloplasty

BACKGROUND AND PURPOSE

In select centers, laparoscopic (robot)-assisted pyeloplasty has emerged as a viable approach for the treatment of ureteropelvic junction obstruction (UPJO). Stent placement for urinary diversion is a common postoperative practice with several potential techniques and respective challenges. Robot-assisted diversion techniques such as indwelling Double-J or nephroureteral stents require either additional anesthesia or costs or they carry bleeding risks. Herein we describe an alternative postpyeloplasty cutaneous pyeloureteral (CPU) stenting technique that minimizes these challenges and achieves effective urinary diversion.

External extension of double-J ureteral stent during pyeloplasty: inexpensive stent and non-cystoscopic removal

PURPOSE

The purpose of the study is to describe our experience with the application of externalized double-J ureteral stent (DJUS) during pyeloplasty for correction of ureteropelvic junction obstruction (UPJO) in order to avoid cystoscopy for stent removal.

MATERIALS AND METHODS

Pyeloplasty was performed in 523 infants with UPJO using miniature pyeloplasty technique. After removing the obstructed segment, a 3-Fr. DJUS was placed into the ureter. In order to avoid cystoscopy for the removal of the stent, a feeding tube was passed through the skin and renal pelvis via a separate stab incision, connected to the DJUS and secured to the external body surface (skin), and the pyeloplasty was completed. The feeding tube along with the stent was removed after 3-4 weeks, respectively. Postoperative follow-up visits were performed 1, 3, and 6 months after the procedure.

RESULTS

The mean operative time was 49 min (range 41-79). Patients were discharged after 17 ± 2 h (mean ± SD). No patient experienced bladder spasm or anticholinergic administration. Forty-four patients (8.4 %) experienced minor complications including non-febrile urinary tract infections and mild hematuria. No major complication including urinoma, leakage, and stent migration or displacement was observed during the follow-up period. Stent removal was tolerated by 99.8 % of patients in an outpatient setting with minimal discomfort without performing cystoscopy.

CONCLUSIONS

Using external DJUS along with a pyelocutaneous stent extension during pyeloplasty is a safe, feasible, and beneficial technique. This technique resulted in high success rate with minimal cost and no renal injury. The non-cystoscopic stent removal and elimination of urethral catheterization following pyeloplasty are the other advantages of this technique.

The transition from open to laparoscopic pediatric pyeloplasty: a single-surgeon experience

INTRODUCTION

We present outcomes from a single-surgeon experience in a practice that transitioned away from an open towards a strictly laparoscopic approach to the surgical correction of congenital ureteropelvic junction (UPJ) obstruction.

MATERIAL AND METHODS

A retrospective chart review was performed on all patients undergoing a dismembered pyeloplasty for UPJ obstruction by one surgeon in 2004-2010. A total of 75 (49 open group (OG), 26 laparoscopic group (LG)) procedures (4 bilateral, 4 re-operative (1 outside institution)) in 67 (66% male, and 73% white) patients were available for review. Median age was 10 months (<1-132) for the OG and 72 months (2-204) for the LG (p < 0.001). The UPJ obstruction was left in 55%, right 34% and bilateral in 11%. A crossing vessel was present in 32% of procedures. None of these values were statistically different in comparing the two cohorts. Patients either had SFU grade IV hydronephrosis, worsening SFU Grade III with tension, or were symptomatic. A total of 36 patients presented symptomatically. Co-morbidities were present in 9%. All patients in the LG were stented post-op compared to 35% in the OG (p < 0.001). Outcome variables assessed included learning curve, post-op result (worse, improved, same), complications, need for intervention and length of stay. The surgeon had some exposure in residency to hand-assisted laparoscopy. In pediatric urology fellowship, all complex procedures were performed open.

RESULTS

Mean operative time was significantly longer in the LG: 387 min vs 281 min in the OG (p < 0.001). The learning curve trend line for both cohorts demonstrated slight improvement over time, but confidence intervals were wide in both and this trend was not significant. Following surgical intervention, the length of stay was comparable between the two groups with 96% discharged post-op day 1 in LG and 87% in OG (p = 0.2). With a minimal follow-up of 6 months, most patients demonstrated improvement in hydronephrosis (LG 96% vs OG 96%). Re-operation was successfully performed in 3 patients (2 OG, 1 LG) for persistent obstruction. Complications were present in both groups: 14% OG and 8% LG (p = NS).

CONCLUSIONS

In summary, it is feasible to successfully transition from an open surgical practice towards a strictly laparoscopic approach to the surgical correction of UPJ obstruction. Even in the absence of laparoscopic training in fellowship, the learning curve should be relatively flat with the laparoscopic repair but will always take longer than the open procedure.

Comparison of Surgical Outcomes between Dismembered Pyeloplasty with or without Ureteral Stenting in Children with Ureteropelvic Junction Obstruction

PURPOSE

To evaluate the impact of temporary internal ureteral stents on the surgical outcomes of dismembered pyeloplasty in children.

MATERIALS AND METHODS

The medical records of 70 children (76 renal units) who underwent dismembered pyeloplasty for ureteropelvic junction (UPJ) obstruction at at Asan Medical Center between January 2005 and December 2010 were retrospectively reviewed. We classified the renal units into the stented group (22 renal units) and the nonstented group (54 renal units). Fifty-four of 70 patients were male and their mean age was 2.2±3.8 years old. The mean follow-up period was 29.6±16.8 months.

RESULTS

Sixty-four children had unilateral UPJ obstruction. The mean stent duration was 31.9 days. As shown by evaluation of radiologic images, there were no significant differences between the stented group and the nonstented group during the follow-up period (p>0.05). The mean preoperative and postoperative anteroposterior pelvic diameters (APPDs) of the nonstented group were 31.3 mm and 15.1 mm, respectively (p<0.001). The preoperative and postoperative grades of hydronephrosis were 3.9 and 2.9, respectively (p=0.037). The mean preoperative and postoperative APPDs of the stented group were 36.4 mm and 15.6 mm, respectively (p<0.001). The preoperative and postoperative grades of hydronephrosis were 4 and 3.1, respectively (p<0.001). Repeat obstruction was shown in 4 subjects as a postoperative complication (5.7%). Two children from each group had recurrent UPJ obstruction, with percentages of 3.7% and 9%, respectively (p=0.575).

CONCLUSIONS

In a comparison of nonstented and stented groups during pediatric dismembered pyeloplasty for UPJ obstruction, no significant differences were found in the resolution of hydronephrosis or overall postoperative complications.

Complications of trans-anastomotic externalised stents in open pyeloplasty: influence of the method of placement, the duration of stenting, and the associated bladder drainage

PURPOSE

To assess the influence of the method for stent placement, the duration of stenting, and the presence of bladder drainage on the complication rate of open pyeloplasty.

PATIENTS AND METHODS

Complications were, retrospectively, compared in 228 consecutive open pyeloplasties performed at institution A using a trans-pyelostomic 6-Fr splint/stent for 5 days and no bladder drainage, and 150 consecutive open pyeloplasties performed at institution B using a trans-nephrostomic 6-Fr splint/stent for 9 days plus bladder drainage.

RESULTS

Median age at surgery was comparable between groups. The overall complication rate was 13% and was comparable at the two institutions, but for the presence of perioperative bleeding that was more common when the stent was placed trans-nephrostomically (institution B) and the rate of stent dislodgements, which was lower at institution A, perhaps due to some technical details aiming to prevent any inadvertent traction on the stent. Additional procedures, such as double J internal stent insertion, were required in <2% of cases.

CONCLUSIONS

A 5-day period of stenting after open pyeloplasty is generally enough. Trans-nephrostomic and trans-pyelostomic stent placement is equally effective. However, the former can be associated with a slightly higher bleeding rate. Details during stent placement are keys to avoid postoperative dislodgement and malfunctioning. Systematic bladder drainage seems unnecessary.

Dismembered pyeloplasty using double 'J' stent in infants and children

PURPOSE

The purpose of the present study was to comprehensively assess the results of dismembered pyeloplasty in pelvi-ureteric junction obstruction (PUJO) using double 'J' ureteric stent.

MATERIALS AND METHODS

Records of 61 dismembered pyeloplasties in 60 consecutive patients with PUJO who underwent pyeloplasty in a 5-year period were reviewed retrospectively. In 58 cases, a double 'J' stent was passed in an antegrade fashion during the operation. No other mode of drainage was used. Stent was not placed on three occasions. Records were reviewed for age at diagnosis, age at surgery, post-operative complication, post-operative drainage and length of hospital stay.

RESULTS

There were no episodes of urinary leak or re-obstruction in the stented group. Median post-operative stay in stented patients was 2 days. The use of this stent was associated with no serious complications. There were no episodes of post-operative urinary tract infection or stent displacement.

CONCLUSIONS

We recommend double 'J' stent as the safest mode of drainage in pyeloplasty in infants and children. Keeping a double-J stent across the anastomosis reduces the complications and the hospital stay in these patients.

Ureteric stents in pyeloplasty: a help or a hindrance?

OBJECTIVE

To examine whether routine ureteric stenting influences outcome of pyeloplasty for pelvi-ureteric junction obstruction (PUJO).

PATIENTS AND METHODS

A 10-year review was conducted of 105 consecutive open Anderson-Hynes dismembered pyeloplasties performed for PUJO, covering two periods: (1) pyeloplasties performed without ureteric stents (1994-1998) and (2) pyeloplasties performed with ureteric stents (1999-2003). Outcomes (expressed as means+/-SEM) of unstented patients (UPs; n=47) and stented patients (SPs; n=58) were compared and results analysed using ANOVA and chi-square tests.

RESULTS

Fifty-five patients (53.9%) presented with antenatal hydronephrosis, whilst 47 (46.1%) presented postnatally (at mean age 88.4+/-7.1 months) with one or more of the following: pain (n=30, 63.8%), urinary tract infection (n=16; 34.0%), haematuria (n=3, 6.4%), abdominal mass (n=3, 6.4%), acute renal failure (n=2, 4.3%), incidental finding (n=4, 8.5%). Pyeloplasty was performed (at mean age 58.9+/-5.3 months) for one or more of the following: pain (n=40, 38.1%), haematuria (n=6, 5.7%), urinary tract infection (n=18, 17.1%), poor initial or deteriorating function (n=29, 27.6%), severe or deteriorating hydronephrosis (n=41, 39.0%), calculus (n=1, 0.95%). Recognised complications of surgery were significantly higher in UPs (5 of 47; 10.6%) than SPs (0 of 58); P=0.016. These were leakage (n=4, 8.5%) and obstruction by blood clot (n=1, 2.1%). Nine SPs (15.5%) developed stent-related complications, including stent migration (n=5, 8.6%), infection (n=3, 5.2%) and calculus (n=1, 1.7%). SPs had significantly shorter hospital stay (2.71+/-0.25 days) than UPs (4.30+/-0.38 days); P<0.01. Preoperative renal pelvis antero-posterior diameter in SPs (3.24+/-0.25 cm) and UPs (3.21+/-0.28 cm) was comparable (P=0.80). Following pyeloplasty, a significant improvement from these preoperative baselines occurred earlier in SPs (at 3.10+/-0.46 months) than UPs (at 15.71+/-3.05 months); P<0.01.

CONCLUSION

Stented pyeloplasty significantly reduces complications from surgery, particularly leakage, and results in shorter hospital stay and earlier resolution of hydronephrosis, but at the expense of stent-related complications which could be avoided in future by the use of external stents.

The effects of ureteral mobilization and transection on ureteral oxygenation

OBJECTIVES

To determine the impact of ureteral transection with and without prior ureteral mobilization on ureteral oxygen partial pressure (p(u)O(2)).

METHODS

Sixteen pigs underwent general anesthesia with laparoscopic transperitoneal access to the right ureter. With no dissection and minimal manipulation, a tissue oxygen probe (Licox, Kiel, Germany) was introduced via a trocar and inserted into the ureter. The probes were placed at the ureteropelvic junction (UPJ, n = 8) and ureterovesical junction (UVJ, n = 8). Baseline p(u)O(2) was measured. Subsequently, half of the animals at each level (n = 4) underwent complete ureteral transection proximal to UPJ probes and distal to UVJ probes with or without prior mobilization. p(u)O(2) levels were measured after ureteral mobilization and transection.

RESULTS

Of the ureters transected at the UPJ without mobilization, the mean p(u)O(2) level declined by 13 mm Hg relative to baseline (P = 0.07). The baseline UPJ p(u)O(2) level declined by 5 mm Hg after ureteral mobilization alone and subsequently by 31 mm Hg after transection (P <0.01). Of the ureters transected at the UVJ without mobilization, the p(u)O(2) level decreased by 4 mm Hg relative to baseline (P = 0.08). The baseline UVJ p(u)O(2) level decreased by 15 mm Hg after ureteral mobilization alone and subsequently by 39 mm Hg after transection (P <0.01). At both the UPJ and UVJ, the transected-only p(u)O(2) level was statistically higher than the mobilized and transected level (P = 0.03, respectively).

CONCLUSIONS

During ureteral surgery, mobilization alone exposes the distal ureter to more ischemia than the proximal ureter, and efforts to minimize ureteral mobilization when transection is necessary are crucial in maintaining tissue oxygenation.

Symptomatic ureteropelvic junction obstruction in children in the era of prenatal sonography-is there a higher incidence of crossing vessels?

OBJECTIVES

To determine whether prenatal sonography and early detection and correction of ureteropelvic junction obstruction (UPJO) has changed the incidence of crossing vessels as the etiology of obstruction in older children presenting with symptomatic UPJO.

METHODS

We reviewed the medical records of all children and adolescents who underwent pyeloplasty for symptomatic UPJO between 1986 and 1999, during the era of widespread use of prenatal sonography. Operative notes were used to determine which patients had obstruction due to lower pole crossing vessels.

RESULTS

Thirty-eight patients were identified who underwent pyeloplasty for symptomatic UPJO. Lower pole vessels were identified in 22 (58%) of 38 patients (P <0.0001 compared with historical controls). All patients underwent dismembered pyeloplasty and remained asymptomatic after surgery, with renal scans demonstrating excellent drainage and preservation of function.

CONCLUSIONS

Prenatal ultrasonography has increased the incidence of crossing vessels as the etiology of UPJO in young children and adolescents presenting with symptomatic UPJO compared with the historical incidence of 11% to 15%. This finding may impact treatment recommendations with respect to endourologic management of the obstruction in this patient population. Currently, we recommend open dismembered pyeloplasty for young children and adolescents presenting with symptomatic UPJO.