Pediatric Urology Coexisting Ureteropelvic Junction Obstruction and Ureterovesical Junction Obstruction: Is Pyeloplasty Always the Preferred Initial Surgery? Yong Seung Lee, Young Jae Im, Hyeyoung Lee, Myung-Joon Kim, Mi-Jung Lee, Hyun Jin Jung, and Sang Won Han OBJECTIVE MATERIALS AND METHODS RESULTS
CONCLUSION
To report our experience with the diagnosis and management of coexisting ureteropelvic junction obstruction (UPJO) and ureterovesical junction obstruction (UVJO). Among the pediatric patients who underwent pyeloplasty or ureteroneocystostomy from 20032012, 15 patients were diagnosed with coexisting UPJO and UVJO. We retrospectively analyzed their medical records. Of the 15 patients with coexisting UPJO and UVJO, the correct diagnosis was made preoperatively in 10 patients (66.7%). In 4 other patients, only UPJO was diagnosed, and in 1 patient, only UVJO was diagnosed. The decision of where to initially operate was determined from the combined results of the preoperative antegrade evaluation and retrograde ureteropyelography. Pyeloplasty was the initial surgical management choice for 9 patients, and ureteroneocystostomy was the initial surgical approach in 5 patients. In 1 patient, both pyeloplasty and ureteroneocystostomy were performed simultaneously. Of the 9 patients who underwent initial pyeloplasty, additional ureteroneocystostomy was required in 2. Additional pyeloplasty was required in 2 of the 5 patients who initially underwent ureteroneocystostomy. It is often difficult to correctly diagnose coexisting UPJO and UVJO. In patients with UPJO, it is highly recommended that retrograde ureteropyelography be performed before pyeloplasty to evaluate the distal uretereureterovesical junction. Initial pyeloplasty is not always recommended as a first-line therapy. UROLOGY 83: 443e450, 2014. 2014 Elsevier Inc.
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reteropelvic junction (UPJ) obstruction (UPJO) and ureterovesical junction (UVJ) obstruction (UVJO) are 2 main causes of pediatric hydronephrosis.1,2 Pyeloplasty and ureteroneocystostomy (UNC) are well-established as effective treatments of UPJO and UVJO, respectively.3,4 However, UPJO and UVJO that coexist in the same ureter is a rare condition, and it is often difficult to diagnose both disorders correctly and manage them properly.5 Only a few reports have been previously published of this combined condition.6-8 Most of these reports have described difficulties in establishing the correct diagnosis; however, once both disorders were diagnosed, pyeloplasty was usually recommended as the initial surgical approach. We report our experience with the diagnosis and Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea; the Department of Radiology, Yonsei University College of Medicine, Seoul, Korea; and the Department of Urology, Catholic University of Daegu School of Medicine, Daegu, Korea Reprint requests: Sang Won Han, M.D., Department of Urology and Urological Science Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea. E-mail: [email protected] Submitted: May 25, 2013, accepted (with revisions): August 20, 2013
ª 2014 Elsevier Inc. All Rights Reserved
management of coexisting UPJO and UVJO in pediatric patients.
MATERIAL AND METHODS With approval of the institutional review board of Severance Hospital (4-2013-0178), we performed a retrospective cohort analysis.
Patients From 2003-2012, pediatric pyeloplasty for UPJO and UNC for UVJO were performed in 389 patients and 58 patients, respectively, at our institution. Of these patients, 15 were diagnosed with coexisting UPJO and UVJO. We retrospectively analyzed their medical records.
Data Collection All patients underwent ultrasonography, radioisotope imaging, and voiding cystourethrography before surgery. In most patients, antegrade urinary tract evaluation was performed at least once with a technetium-99m mercaptoacetyl-triglycine (MAG-3) scan. In the case of referral from another institution after percutaneous nephrostomy, antegrade pyeloureterography was 0090-4295/14/$36.00 http://dx.doi.org/10.1016/j.urology.2013.08.087
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performed to evaluate the flow of contrast, and the differential renal function (DRF) was assessed using a dimercaptosuccinic acid (DMSA) scan instead of a MAG-3 scan. In the operating room, retrograde ureteropyelography (RGP) was attempted in all patients before pyeloplasty or UNC. Ultrasonography was performed approximately 6 weeks after surgery and repeated 1-6 months later, depending on the results of the previous study. Radioisotope imaging was performed at 612 months postoperatively and repeated subsequently if needed. We collected the following data to evaluate which factors correlated with a decrease in DRF: sex; age at the initial operation; type of initial operation; preoperative ultrasound, radioisotope imaging, and voiding cystourethrography results; and postoperative ultrasound and radioisotope imaging results. The ultrasound evaluation was performed when the patients had a full bladder after oral hydration. The patients were given extra water to drink in addition to their normal diet; neither intravenous hydration nor diuretics were used. The bladder filling status was assessed before the evaluation, and the evaluation was delayed for approximately 1 hour if filling was insufficient. Hydronephrosis was graded according to the Society for Fetal Urology guidelines.9 All ultrasound evaluations were performed by 2 pediatric radiologists (M.K. and M.L.). DRF was assessed using a DMSA scan or MAG-3 scan. If repeated radioisotope imaging evaluations were performed before surgery, only the 1 closest to the operation was used for data analysis. When radioisotope scans were repeated postoperatively, the last 1 was considered the postoperative study for the purposes of data analysis.
Statistical Analysis Univariate analyses were performed using Fisher’s exact test and Student’s t test. The Statistical Package for Social Sciences, version 18.0, software (SPSS, Chicago, IL) was used. P < .05 was considered statistically significant.
RESULTS Initial Diagnosis Of the 15 patients with coexisting UPJO and UVJO, the correct diagnosis was made preoperatively in 10 patients (66.7%; Table 1). In 4 patients (26.7%), only UPJO was diagnosed preoperatively, and in 1 patient (6.7%), only UVJO was diagnosed preoperatively. The 10 patients with a correct diagnosis preoperatively all had diffuse ureteral dilation with hydronephrosis on ultrasonography and stasis of radionuclide or contrast material at the renal pelvis during the antegrade imaging studies (eg, MAG-3 scans, antegrade pyeloureterography). The half-life of tracer washout from the pelvis was uncountable in all patients who underwent MAG-3 scanning because of severely impaired drainage. The existence of UVJO was not diagnosed preoperatively in 4 patients, because they did not have ureteral dilation on the preoperative ultrasound scan. In these patients, UVJO was found during RGP in the operating room. One of these patients had hydronephrosis with perirenal urinoma, but no dilation of the ureter, on the ultrasound examination performed before surgery (Fig. 1). The size of the urinoma had increased, and pyeloplasty was planned. During RGP, this patient was noted to have 444
ureteral narrowing at the UVJ and diffuse ureteral dilation. In the other 3 patients, ureteral dilation was either never or only occasionally found on their preoperative ultrasound evaluations. These patients displayed no evidence of vesicoureteral reflux (VUR) during voiding cystourethrography. The existence of UPJO was not diagnosed preoperatively in 1 patient, because a preoperative antegrade urinary tract evaluation was not performed. Preoperative ultrasonography revealed hydronephrosis grade III with diffuse ureter dilation. The DMSA scan revealed decreased DRF (35.3%) in the ipsilateral kidney; thus, UNC was planned, because it was assumed that this patient had only UVJO. After general anesthesia was induced, RGP was attempted but failed; the ureteral catheter could not pass through the ureteral orifice owing to severe angulation of the distal ureter at the UVJ. Plication UNC was performed, and temporary ureteral catheter placement was attempted during surgery; however, this also failed, because the ureteral catheter could not pass into the renal pelvis. RGP was attempted again, which was then successful. The results showed narrowing of the ureter at the UPJ, and pyeloplasty was immediately performed. Surgical Management and Outcomes The median age of the 15 patients who underwent pyeloplasty or UNC as their first operation was 5.0 months (interquartile range [IQR] 3.2-12.8). Pyeloplasty was the initial surgical approach in 9 patients, and UNC using the Starr technique for ureter plication10 was the initial surgery in 5 patients (Table 1). In the patient in whom UPJO was not diagnosed preoperatively, both pyeloplasty and plication UNC were performed simultaneously. During a median follow-up period of 39.3 months (IQR 15.3-60.2), an additional UNC or pyeloplasty was required in 4 patients (28.6%) of the 14 patients who had undergone initial pyeloplasty or UNC. Of the 5 patients with initial plication UNC, additional pyeloplasty was required in 2 patients. In another patient who had undergone initial plication UNC, pyeloplasty was planned because of residual postoperative hydronephrosis with decreased renal function. However, RGP revealed no obstruction at either the UPJ or previously operated UVJ; thus, pyeloplasty was not performed. Preoperative DRF was assessed at a median of 0.6 months (IQR 0.4-1.1) before the initial operation. Postoperative DRF was assessed in 13 patients at a median of 11.8 months (IQR 9.5-33.5) after the initial operation. The median preoperative and postoperative DRF value was 43.0 (IQR 37.0-47.0) and 39.0 (IQR 31.0-45.5), respectively. Of the 13 patients with both preoperative and postoperative DRF assessments, the DRF decreased by >5% in 7 patients (53.8%). A decreased DRF by >5% was observed in all 4 patients (100.0%) who had undergone initial UNC but in only 3 of the 9 patients (37.5%) who had undergone initial pyeloplasty. This difference did not reach statistical significance (P ¼ .081). Sex, kidney side (left or right), age at the initial operation, and preoperative UROLOGY 83 (2), 2014
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Table 1. Demographics and characteristics of 15 patients
Pt. Initial Preoperative No. Sex Side Presentation Diagnosis
Preoperative Ultrasound Findings
Distal Age at Ureter Preoperative First Diameter Antegrade Operation (mm) Study (mo)
VUR on VCUG
First Operation
Age at Second Operation (mo)
Second Operation
Stasis at pelvis (MAG-3) Stasis at pelvis (MAG-3)
23.0
No
Pyeloplasty
—
—
2.1
No
Pyeloplasty
—
—
10.8
Stasis at pelvis (AGP)
109.1
No
Pyeloplasty
—
—
HN 3 without ureter dilation, urinoma HN 4 with occasional ureter dilation HN 4 with occasional ureter dilation HN 3 without ureter dilation
No dilation
Stasis at pelvis (MAG-3)
1.3
No
Pyeloplasty
—
—
7.2
Stasis at pelvis (MAG-3)
5.0
No
Pyeloplasty
—
—
7.1
Stasis at pelvis (MAG-3)
1.2
No
Pyeloplasty
—
No dilation
12.0
No
Pyeloplasty
—
HN 4 with diffuse ureter dilation HN 4 with diffuse ureter dilation
24.4
10.2
No
Pyeloplasty
16.7
UNC
14.1
No
Pyeloplasty
20.4
UNC
UPJO þ UVJO
HN 4 with diffuse ureter dilation
11.3
UPJO þ UVJO
HN 3 with diffuse ureter dilation
8.1
Stasis at pelvis, ureter (MAG-3) Stasis at pelvis (AGP) Stasis at pelvis, ureter (MAG-3) Stasis at pelvis, ureter (MAG-3) Stasis at pelvis, ureter (MAG-3)
1
M
R
Prenatal HN
UPJO þ UVJO
2
M
R
Prenatal HN
UPJO þ UVJO
3
F
R Re-current UTI
UPJO þ UVJO
HN 3 with diffuse ureter dilation
4
M
L
Prenatal HN, UTI
UPJO
5
M
L
Prenatal HN
UPJO
6
F
R Prenatal HN
UPJO
7
F
L
Prenatal HN
UPJO
8
M
L
Prenatal HN, UTI
UPJO þ UVJO
9
F
L
Prenatal HN
UPJO þ UVJO
10
F
R Prenatal HN, UTI
11
M
R Prenatal HN, UTI
HN 4 with diffuse ureter dilation HN 4 with diffuse ureter dilation
7.0 8.1
8.0
Preoperative DRF (%)
Postoperative Ultrasound Postoperative Findings DRF (%)
48 (MAG-3) HN 1 without ureter dilation 37 (MAG-3) HN 2 with ureter dilation (5.0 mm) 39 (DMSA) No HN with ureter dilation (7.0 mm) 47 (MAG-3) HN 2 without ureter dilation
N/A 36 (DMSA)
40 (DMSA)
48 (DMSA)
47 (MAG-3) HN 2 without ureter dilation
51 (MAG-3)
Ureteroscopic 43 (MAG-3) HN 2 with ureter stone dilation removal (4.7 mm) — 45 (MAG-3) HN 1 without ureter dilation
20 (DMSA)
45 (DMSA) HN 2 without ureter dilation 46 (MAG-3) HN 2 without ureter dilation
48 (DMSA)
31 (DMSA) 33 (DMSA)
4.5
Contralateral VUR
UNC
—
—
38 (MAG-3) HN 1 without ureter dilation
N/A
12.6
No
UNC
—
—
50 (MAG-3) HN 1 without ureter dilation
43 (MAG-3)
Continued
445
— — UNC þ pyeloplasty No NA 9.2
3.1
RGP 8.5 UNC No 4.6 Stasis at pelvis (MAG-3) 10.0
Pyeloplasty 18.2 UNC No 11.2 Stasis at pelvis (MAG-3) 7.3
UVJO Prenatal HN M 15
L
UPJO þ UVJO Prenatal HN M 14
L
UPJO þ UVJO Prenatal HN L M 13
AGP, antegrade pyeloureterography; DMSA, dimercaptosuccinic acid; DRF, differential renal function; F, female; HN, hydronephrosis; L, left; M, male; MAG-3, technetium-99m mercaptoacetyltriglycine; NA, not applicable; Pt. No., patient number; R, right; RGP, retrograde pyeloureterography; UNC, ureteroneocystostomy; UPJO, ureteropelvic junction obstruction; UTI, urinary tract infection; UVJO, ureterovesical junction obstruction; VCUG, voiding cystourethrography; VUR, voiding cystourethrography.
39 (DMSA)
20 (MAG-3)
31 (DMSA)
42 (DMSA)
HN 4 with ureter dilation (5.2 mm) 42 (MAG-3) HN 4 with ureter dilation (5.0 mm) 31 (MAG-3) HN 2 with ureter dilation (7.0 mm) 35 (MAG-3) HN 2 without ureter dilation 49 (MAG-3) Pyeloplasty 11.8 UNC No 5.0 Stasis at pelvis (MAG-3) 11.5
HN 4 with diffuse ureter dilation HN 3 with diffuse ureter dilation HN 4 with diffuse ureter dilation HN 3 with diffuse ureter dilation UPJO þ UVJO Prenatal HN L F
Pt. Initial Preoperative No. Sex Side Presentation Diagnosis
12
Postoperative Ultrasound Postoperative Findings DRF (%) Preoperative DRF (%) Second Operation VUR on VCUG
First Operation
Age at Second Operation (mo) Distal Age at Ureter Preoperative First Diameter Antegrade Operation (mm) Study (mo) Preoperative Ultrasound Findings Table 1. Continued
446
DRF did not significantly differ between the patients with and without a >5% decrease in DRF postoperatively.
COMMENT UPJO and UVJO are common causes of pediatric hydronephrosis. However, it is difficult to define ureteral “obstruction,” because ureteral obstruction and nonobstruction cannot be clearly differentiated.11 The most popular current definition of ureteral obstruction is that suggested by Koff12: “any restriction to urinary outflow that, if left untreated, will cause progressive renal deterioration.” Using this definition, DRF deterioration and progressive renal parenchymal thinning are considered important signs of UPJO and UVJO and provide an indication for surgery. Nevertheless, when UPJO and UVJO coexist, this definition leads to confusion in both diagnosis and management. When deteriorating renal function is encountered in this situation, it is difficult to know whether the deterioration has resulted from the UPJ or UVJ narrowing and which surgery would be most appropriate. A few reports have described the coexistence of UPJO and UVJO, and most of these studies have had difficulties in establishing the correct diagnosis. McGrath et al6 reported that the diagnosis of coexisting UPJO and UVJO was possible preoperatively in 3 (21.4%), intraoperatively in 3 (21.4%), and postoperatively in 8 (57.1%) of the 14 patients they described. The correct diagnosis was made preoperatively in 5 of 11 patients (45.4%) in the study by Pesce et al7 and in 5 of 14 patients (35.7%) in the report by Cay et al.8 In the present study, coexisting UPJO and UVJO was diagnosed preoperatively in 10 of 15 patients (66.7%). The correct preoperative diagnosis was possible when stasis of radionuclide or contrast material was present in the renal pelvis during an antegrade study (eg, MAG-3, antegrade pyeloureterography) combined with diffuse ureteral dilation on ultrasonography. Of the 5 patients without a correct preoperative diagnosis, ultrasonography revealed either no or only occasional ureter dilation in 4 patients, and an antegrade study was not performed in 1 patient. If one encounters occasional ureteral dilation on ultrasonography, along with an UPJO pattern on an antegrade study, the possibility of coexisting UVJO or VUR should be considered. Whether to perform a whole ureter evaluation with RGP before pyeloplasty has been a matter of debate. Cockrell and Hendren13 found unpredicted findings during RGP in 36 of 100 patients diagnosed with UPJO and evaluated with RGP before pyeloplasty. Tortuosity of the upper ureter and >1 area of narrowing were included in their unpredicted findings. In contrast, Rushton et al14 suggested not performing RGP before pyeloplasty because the possibility of a distal ureteral obstruction could be excluded by preoperative ultrasonography and diuretic renography. However, Moodley et al5 reported 2 cases of coexisting UPJO and UVJO that were diagnosed only after RGP evaluation. We noted the same phenomenon UROLOGY 83 (2), 2014
Figure 1. Preoperative ultrasound scan of a male patient performed 20 days after birth revealing left hydronephrosis with (A) perirenal urinoma but (B) no ureter dilation. (C) Retrograde pyeloureterography revealed narrowing at the ureterovesical junction and ureteropelvic junction with diffuse ureteral dilation. Although a 3F ureteral catheter could pass through the narrowed portion at the ureterovesical junction, it could not pass through the ureteropelvic junction. The patient underwent pyeloplasty as initial surgical treatment; (D) intravenous pyelography performed 22 months after surgery showed improved hydronephrosis and distal ureter dilatation. The pathologic features of ureterovesical junction could have been either ureterovesical junction obstruction or nonobstructed, nonrefluxing megaureter, which could not be differentiated in this patient.
in our 4 patients, who were diagnosed only with UPJO preoperatively. A preoperative RGP evaluation could be helpful to not only determine the exact location of the UPJ, but also assess the status of the distal ureter and the possibility of concurrent UVJO. Although retrograde UPJ evaluation using RGP is not always possible owing to either the difficulty of contrast passing through the UVJ or severe kinking of the distal ureter, it could reduce the possibility of a misdiagnosis of coexisting UPJO and UVJO when combined with a preoperative antegrade evaluation. Even after the diagnosis of coexisting UPJO and UVJO has been established, determining the first site for surgery is a remaining question. We performed simultaneous plication UNC and pyeloplasty in 1 patient. Although UROLOGY 83 (2), 2014
postoperative DRF recovery occurred in this patient, simultaneous procedures on the UPJ and UVJ are not generally recommended because of the potential negative effect on ureteral vascularity. Previous reports have recommended pyeloplasty as the initial surgical management for this group of patients. In the study by McGrath et al,6 all 6 patients with initial UNC required additional pyeloplasty, but only 2 of 5 patients with initial pyeloplasty required subsequent UNC. Pesce et al7 and Cay et al8 performed initial pyeloplasty, because the natural resolution rate of UVJO has been greater than that of UPJO. The possible existence of a nonobstructed, nonrefluxing megaureter requiring no operation could be another reason for initial pyeloplasty before UNC. Differentiating UVJO from a nonobstructed, nonrefluxing megaureter is 447
difficult. Although all dilated ureters do not always indicate the existence of ureteral obstruction, no reference standard method is available with which to differentiate one from the other.15 Only repeated investigations and comparing the changes in the variables have been recommended. Moreover, when coexisting with UPJO, antegrade studies often will not reveal the stasis at the ureter, and exact differentiation can be nearly impossible. Initial pyeloplasty and serial follow-up of the distal ureter might prevent unnecessary UNCs. The success rate of each operation could also be considered. The success rate of plication UNC using the Starr method is known to be around 93%-95%,16,17 and that of pyeloplasty is reported to be 95%-99%.14,18 Although a direct comparison between the different operations is difficult, the success rate of pyeloplasty seems to be greater. Nevertheless, we chose the operation according to the combined results of the antegrade and retrograde evaluations, except for the 1 patient without a preoperative antegrade study. We had 2 reasons for our decision to perform initial UNC in 5 patients. Although the natural resolution rate of UVJO has been greater than that of UPJO, resolution depends on the diameter of the ureter.19,20 For patients with severe ureteral dilation, we have considered performing UNC rather than pyeloplasty as the initial surgical management. The other reason was the possibility of spontaneous resolution of secondary UPJO after treatment of UVJO. Distal ureter pathologic entities, such as VUR and UVJO, is known to cause secondary UPJO.21 Although the pathophysiology has not been fully proven, ureter kinking, stretching of the renal pelvis causing atonicity, inflammation, and ureteritis have been suspected as causes of secondary UPJO from VUR.21,22 This might be similar in cases of secondary UPJO caused by UVJO, because UVJO could also be a cause of these conditions. However, whether resolution of the primary pathologic entity could resolve the secondary UPJO has not been firmly established. In cases of secondary UPJO caused by VUR, initial pyeloplasty has been suggested to be a better initial management modality than the correction of VUR.23 However, a recent report by Ebadi et al24 demonstrated resolution of UPJO after endoureterotomy for distal UVJO. In our study, only 2 of 5 patients with initial UNC required additional pyeloplasty. These cases have thus illustrated that initial pyeloplasty is not always the most appropriate first-line therapy. Nevertheless, whatever the initial surgery might be for patients with coexisting UPJO and UVJO, the possibility of requiring additional operations should be remembered. In our study, 28.6% of patients who had undergone initial pyeloplasty or initial UNC required an additional operation. In previous reports concerning coexisting UPJO and UVJO, the additional operation rate varied. In the report by Pesce et al,8 they performed initial pyeloplasty followed by UNC in all patients with coexisting UPJO and UVJO. In contrast, McGrath et al6 performed additional UNC in 40% of patients with initial pyeloplasty. A 448
report by Ebadi et al24 stated that only 6.4% of patients required additional pyeloplasty after initial endoureterotomy for UVJO. The wide range of additional operation rates has revealed the difficulty of treating coexisting UPJO and UVJO, even after the initial operation. It is often difficult to decide whether and where to operate when persistent hydronephrosis with decreased DRF after initial pyeloplasty or UNC has been encountered. DRF has been criticized for its poor correlation with renal histologic changes and low predictive potential for future renal function.25 Moreover, even if the DRF is correct, it is still challenging to differentiate delayed recovery or failure of the previous operation from aggravation of the obstruction that has not been treated. The present study had certain limitations. For example, the retrospective design of the study led to the potential for selection bias. Moreover, we diagnosed coexisting UPJO and UVJO and then decided where to operate using the combined results of the antegrade and retrograde evaluations. This decision could have had an element of subjectivity. In particular, although megaureter is considered present when the diameter of a ureter is >7-8 mm, it was not considered present in 4 patients whose UVJO was diagnosed during the RGP evaluation. Although we found prominent ureteral dilation in RGP, we did not measure the exact diameter during the procedure. In 2 patients with a percutaneous nephrostomy tube, a pressure flow study such as the Whitaker test would have been more helpful in making the diagnosis, if performed. In addition, postoperative radioisotope imaging in the present study was mostly DMSA scanning, and MAG-3 scans were taken preoperatively. We preferred a postoperative evaluation with DMSA scan and intravenous pyeloureterography, rather than the MAG-3 scan, for patients with coexisting UPJO and UVJO. It was helpful to visualize the whole ureter at a glance and to get information on the DRF. The evaluation of transit time with the MAG-3 scan is widely known to be inaccurate.26 Nevertheless, if we could compare the half-life of the tracer postoperatively with that from a preoperative study, it would have been helpful. Finally, the number of patients was small, and the type of initial operation was not controlled. Additional larger, controlled studies should provide more definitive information for determining whether pyeloplasty or UNC is the most appropriate initial surgery.
CONCLUSION It is difficult to correctly diagnose coexisting UPJO and UVJO. Before pyeloplasty in patients with UPJO, RGP is strongly recommended to assess both the distal ureter and the UVJ. Initial pyeloplasty should not always be recommended as the first-line therapy, because of the possibility of secondary UPJO caused by UVJO. References 1. Lebowitz RL, Griscom NT. Neonatal hydronephrosis: 146 cases. Radiol Clin North Am. 1977;15:49-59.
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2. Brown T, Mandell J, Lebowitz RL. Neonatal hydronephrosis in the era of sonography. AJR Am J Roentgenol. 1987;148:959-963. 3. O’Reilly PH, Brooman PJ, Mak S, et al. The long-term results of Anderson-Hynes pyeloplasty. BJU Int. 2001;87:287-289. 4. DeFoor W, Minevich E, Reddy P, et al. Results of tapered ureteral reimplantation for primary megaureter: extravesical versus intravesical approach. J Urol. 2004;172:1640-1643; discussion 1643. 5. Moodley P, Demaria J, Lorenzo AJ, et al. Concurrent ureteropelvic and ureterovesical junction obstruction in children: the value of retrograde pyelography. J Pediatr Urol. 2010;6:117-121. 6. McGrath MA, Estroff J, Lebowitz RL. The coexistence of obstruction at the ureteropelvic and ureterovesical junctions. AJR Am J Roentgenol. 1987;149:403-406. 7. Pesce C, Musi L, Campobasso P, et al. Coexisting pelviureteral and vesicoureteral junction obstruction in children. Eur J Pediatr Surg. 2003;13:367-371. 8. Cay A, Imamoglu M, Bahat E, et al. Diagnostic difficulties in children with coexisting pelvi-ureteric and vesico-ureteric junction obstruction. BJU Int. 2006;98:177-182. 9. Fernbach SK, Maizels M, Conway JJ. Ultrasound grading of hydronephrosis: introduction to the system used by the Society for Fetal Urology. Pediatr Radiol. 1993;23:478-480. 10. Starr A. Ureteral plication: a new concept in ureteral tailoring for megaureter. Invest Urol. 1979;17:153-158. 11. Tekgül S, Riedmiller H, Dogan H, et al. Dilation of the upper urinary tract (ureteropelvic junction and ureterovesical junction obstruction). In: Guidelines on Paediatric Urology. European Association of Urology; European Society for Paediatric Urology; Arnheim, The Netherlands: European Association of Urology; 2013;13:61-64. 12. Koff SA. Problematic ureteropelvic junction obstruction. J Urol. 1987;138:390. 13. Cockrell SN, Hendren WH. The importance of visualizing the ureter before performing a pyeloplasty. J Urol. 1990;144:588-592; discussion 584-593. 14. Rushton HG, Salem Y, Belman AB, et al. Pediatric pyeloplasty: is routine retrograde pyelography necessary? J Urol. 1994;152:604-606. 15. Shokeir AA, Nijman RJ. Primary megaureter: current trends in diagnosis and treatment. BJU Int. 2000;86:861-868. 16. Perdzynski W, Kalicinski ZH. Long-term results after megaureter folding in children. J Pediatr Surg. 1996;31:1211-1217. 17. Parrott TS, Woodard JR, Wolpert JJ. Ureteral tailoring: a comparison of wedge resection with infolding. J Urol. 1990;144:328-329. 18. Woo HH, Farnsworth RH. Dismembered pyeloplasty in infants under the age of 12 months. Br J Urol. 1996;77:449-451. 19. Ranawaka R, Hennayake S. Resolution of primary non-refluxing megaureter: an observational study. J Pediatr Surg. 2013;48:380-383. 20. McLellan DL, Retik AB, Bauer SB, et al. Rate and predictors of spontaneous resolution of prenatally diagnosed primary nonrefluxing megaureter. J Urol. 2002;168:2177-2180; discussion 2180. 21. Wein AJ, Kavoussi LR, Campbell MF, eds. Campbell-Walsh Urology, 10th ed. Philadelphia: Elsevier Saunders; 2012. 22. Whitaker RH. Methods of assessing obstruction in dilated ureters. Br J Urol. 1973;45:15-22. 23. Lebowitz RL, Blickman JG. The coexistence of ureteropelvic junction obstruction and reflux. AJR Am J Roentgenol. 1983;140:231-238. 24. Ebadi M, Kajbafzadeh AM, Tourchi A, et al. Endoureterotomy as the initial management of concurrent ureteropelvic and ureterovesical junction obstruction after failed conservative therapy. Urology. 2013;82:214-219. 25. Elder JS, Stansbrey R, Dahms BB, et al. Renal histological changes secondary to ureteropelvic junction obstruction. J Urol. 1995;154: 719-722. 26. Gearhart JP, Rink RC, Mouriquand PDE. Pediatric Urology, 2nd ed. Philadelphia: Elsevier; 2010.
hydronephrosis still is a puzzling situation, because we lack reliable standards for evaluation and indications for surgery. Rarely, do UVJO and UPJO coexist, although radiologic evaluation findings might suggest otherwise. The authors, using Society for Pediatric Urology criteria, categorized all patients in this series as having grade 3 or 4 hydronephrosis, groups more likely to undergo surgery. All were investigated because of the finding of antenatal hydronephrosis, except for 1 older, symptomatic child. Experience has shown that many cases of hydronephrosis diagnosed in asymptomatic neonates improve or resolve during observation. In patients with presumed megaureter, in particular, we have learned that with watchful waiting, especially when the ureteral diameters are 1.2 cm. Of these 5, 80% were 1.2 cm in diameter; hence, the issue of a “surgical megaureter” must be questioned. Additionally, 3 patients underwent lower ureteral surgery, despite minimal or no dilation, but because of difficulty inserting ureteral catheter and/or some dilation found on the retrograde pyelogram. As objective as we try to be, the subjective bias of a surgeon can be great, not to mention parental angst and cultural influence, and all these come into play in decision making. The dilemma becomes even more substantial, when additional tests, especially when they are primarily anatomic, suggest >1 potential “surgically correctable” entity might be present. In our practice of 5 experienced surgeons, we have routine disagreements regarding when retrograde pyelography is indicated in patients undergoing pyeloplasty for UPJO or lower ureteral surgery for megaureter. Some of our group believe that retrograde pyelography is indicated for all such patients. Others of us believe instrumentation in straightforward cases can be meddlesome because it can potentially traumatize the ureteral orifice and could open a Pandora’s box by uncovering a minor issue that might be construed as significant. Many of us still fall into the trap of equating bad appearance with bad function. This speaks to the point that judgment is required in each individual case to identify those anatomic curiosities that have a potential physiologic effect. We lack a single reference standard study that can define when intervention is necessary, especially when so many cases of hydronephrosis and/or hydorureteronephrosis are transient rather than pathologic in nature. Martin A. Koyle, M.D., Section of Pediatric Urology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada http://dx.doi.org/10.1016/j.urology.2013.08.089 UROLOGY 83: 449, 2014. 2014 Elsevier Inc.
REPLY EDITORIAL COMMENT Although this report asks a perplexing question, I am still uncertain that a definitive answer is forthcoming. Significant UROLOGY 83 (2), 2014
Because the rate of spontaneous remission is high, most primary megaureters require no surgical intervention. Surgical management has been indicated only for patients with recurrent urinary 449
tract infection, a decrease in the DRF, and significant obstruction.1 The degree of hydronephrosis and the diameter of ureter have been known to affect the natural resolution rate. McLellan et al2 reported that a megaureter with diameter >10 mm might require surgical management. Recently, Ranawaka and Hennayake3 reported the natural resolution rate of patients with megaureter by classifying them into groups according to the ureter diameter. In their study, 1 group with a ureter diameter of 10 mm, had a resolution rate of only 17%. The indications for operation and the natural resolution rate relating to the ureter diameter were similar in our institution. In this study, however, the preoperative ureter diameter measured on ultrasonography was not its real diameter owing to the coexisting UPJO. Preoperative ultrasonography revealed no or occasional ureter dilation in 4 patients and RGP showed prominent ureter dilation. Even in the other 11 patients, preoperative ultrasonography might have underestimated the ureter diameter owing to the obstruction effect at the UPJ. It is also the reason for plication during megaureter correction. We usually perform plication ureteroneocystostomy when the ureter diameter is >10 mm. Although the preoperative ureter diameter measured on ultrasonography was not >10 mm in most patients, RGP revealed severe dilation, and plication was performed during the surgery. RGP before pyeloplasty has been recommended generally, because it can evaluate the entire ureter.4,5 Confirming the diagnosis, demonstrating the exact site and shape of the obstruction, and showing unpredicted abnormal anatomic findings before repair can be helpful. We agree, however, with the editorial comment that the potential for trauma to the ureteral
450
orifice during the procedure exists. It should be performed with care, especially in neonates and infants. Although many reports have been published concerning pediatric ureteral obstruction, most of them focused on the technical aspects of the operation. This particular field still has questions that need to be answered. The development of new biomarkers to exactly assess the kidney injury and advanced functional imaging studies would be helpful. Yong Seung Lee, M.D., Rosito T. Bascuna, Jr, M.D., Hyeyoung Lee, M.D., Young Jae Im, M.D., and Sang Won Han, M.D., Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea
References 1. Tekgül S, Riedmiller H, Dogan H, et al. Dilation of the upper urinary tract (ureteropelvic junction and ureterovesical junction obstruction). In: Guidelines on Paediatric Urology. European Association of Urology; European Society for Paediatric Urology; Arnheim, The Netherlands: European Association of Urology; 2013;13:61-64. 2. McLellan DL, Retik AB, Bauer SB, et al. Rate and predictors of spontaneous resolution of prenatally diagnosed primary nonrefluxing megaureter. J Urol. 2002;168:2177-2180; discussion 2180. 3. Ranawaka R, Hennayake S. Resolution of primary non-refluxing megaureter: an observational study. J Pediatr Surg. 2013;48:380-383. 4. Wein AJ, Kavoussi LR, Campbell MF, eds. Campbell-Walsh Urology, 10th ed. Philadelphia: Elsevier Saunders; 2012. 5. Gearhart JP, Rink RC, Mouriquand PDE. Pediatric Urology, 2nd ed. Philadelphia: Elsevier; 2010.
http://dx.doi.org/10.1016/j.urology.2013.08.090 UROLOGY 83: 449e450, 2014. 2014 Elsevier Inc.
UROLOGY 83 (2), 2014
CONCLUSION
To report our experience with the diagnosis and management of coexisting ureteropelvic junction obstruction (UPJO) and ureterovesical junction obstruction (UVJO). Among the pediatric patients who underwent pyeloplasty or ureteroneocystostomy from 20032012, 15 patients were diagnosed with coexisting UPJO and UVJO. We retrospectively analyzed their medical records. Of the 15 patients with coexisting UPJO and UVJO, the correct diagnosis was made preoperatively in 10 patients (66.7%). In 4 other patients, only UPJO was diagnosed, and in 1 patient, only UVJO was diagnosed. The decision of where to initially operate was determined from the combined results of the preoperative antegrade evaluation and retrograde ureteropyelography. Pyeloplasty was the initial surgical management choice for 9 patients, and ureteroneocystostomy was the initial surgical approach in 5 patients. In 1 patient, both pyeloplasty and ureteroneocystostomy were performed simultaneously. Of the 9 patients who underwent initial pyeloplasty, additional ureteroneocystostomy was required in 2. Additional pyeloplasty was required in 2 of the 5 patients who initially underwent ureteroneocystostomy. It is often difficult to correctly diagnose coexisting UPJO and UVJO. In patients with UPJO, it is highly recommended that retrograde ureteropyelography be performed before pyeloplasty to evaluate the distal uretereureterovesical junction. Initial pyeloplasty is not always recommended as a first-line therapy. UROLOGY 83: 443e450, 2014. 2014 Elsevier Inc.
U
reteropelvic junction (UPJ) obstruction (UPJO) and ureterovesical junction (UVJ) obstruction (UVJO) are 2 main causes of pediatric hydronephrosis.1,2 Pyeloplasty and ureteroneocystostomy (UNC) are well-established as effective treatments of UPJO and UVJO, respectively.3,4 However, UPJO and UVJO that coexist in the same ureter is a rare condition, and it is often difficult to diagnose both disorders correctly and manage them properly.5 Only a few reports have been previously published of this combined condition.6-8 Most of these reports have described difficulties in establishing the correct diagnosis; however, once both disorders were diagnosed, pyeloplasty was usually recommended as the initial surgical approach. We report our experience with the diagnosis and Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea; the Department of Radiology, Yonsei University College of Medicine, Seoul, Korea; and the Department of Urology, Catholic University of Daegu School of Medicine, Daegu, Korea Reprint requests: Sang Won Han, M.D., Department of Urology and Urological Science Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752, Korea. E-mail: [email protected] Submitted: May 25, 2013, accepted (with revisions): August 20, 2013
ª 2014 Elsevier Inc. All Rights Reserved
management of coexisting UPJO and UVJO in pediatric patients.
MATERIAL AND METHODS With approval of the institutional review board of Severance Hospital (4-2013-0178), we performed a retrospective cohort analysis.
Patients From 2003-2012, pediatric pyeloplasty for UPJO and UNC for UVJO were performed in 389 patients and 58 patients, respectively, at our institution. Of these patients, 15 were diagnosed with coexisting UPJO and UVJO. We retrospectively analyzed their medical records.
Data Collection All patients underwent ultrasonography, radioisotope imaging, and voiding cystourethrography before surgery. In most patients, antegrade urinary tract evaluation was performed at least once with a technetium-99m mercaptoacetyl-triglycine (MAG-3) scan. In the case of referral from another institution after percutaneous nephrostomy, antegrade pyeloureterography was 0090-4295/14/$36.00 http://dx.doi.org/10.1016/j.urology.2013.08.087
443
performed to evaluate the flow of contrast, and the differential renal function (DRF) was assessed using a dimercaptosuccinic acid (DMSA) scan instead of a MAG-3 scan. In the operating room, retrograde ureteropyelography (RGP) was attempted in all patients before pyeloplasty or UNC. Ultrasonography was performed approximately 6 weeks after surgery and repeated 1-6 months later, depending on the results of the previous study. Radioisotope imaging was performed at 612 months postoperatively and repeated subsequently if needed. We collected the following data to evaluate which factors correlated with a decrease in DRF: sex; age at the initial operation; type of initial operation; preoperative ultrasound, radioisotope imaging, and voiding cystourethrography results; and postoperative ultrasound and radioisotope imaging results. The ultrasound evaluation was performed when the patients had a full bladder after oral hydration. The patients were given extra water to drink in addition to their normal diet; neither intravenous hydration nor diuretics were used. The bladder filling status was assessed before the evaluation, and the evaluation was delayed for approximately 1 hour if filling was insufficient. Hydronephrosis was graded according to the Society for Fetal Urology guidelines.9 All ultrasound evaluations were performed by 2 pediatric radiologists (M.K. and M.L.). DRF was assessed using a DMSA scan or MAG-3 scan. If repeated radioisotope imaging evaluations were performed before surgery, only the 1 closest to the operation was used for data analysis. When radioisotope scans were repeated postoperatively, the last 1 was considered the postoperative study for the purposes of data analysis.
Statistical Analysis Univariate analyses were performed using Fisher’s exact test and Student’s t test. The Statistical Package for Social Sciences, version 18.0, software (SPSS, Chicago, IL) was used. P < .05 was considered statistically significant.
RESULTS Initial Diagnosis Of the 15 patients with coexisting UPJO and UVJO, the correct diagnosis was made preoperatively in 10 patients (66.7%; Table 1). In 4 patients (26.7%), only UPJO was diagnosed preoperatively, and in 1 patient (6.7%), only UVJO was diagnosed preoperatively. The 10 patients with a correct diagnosis preoperatively all had diffuse ureteral dilation with hydronephrosis on ultrasonography and stasis of radionuclide or contrast material at the renal pelvis during the antegrade imaging studies (eg, MAG-3 scans, antegrade pyeloureterography). The half-life of tracer washout from the pelvis was uncountable in all patients who underwent MAG-3 scanning because of severely impaired drainage. The existence of UVJO was not diagnosed preoperatively in 4 patients, because they did not have ureteral dilation on the preoperative ultrasound scan. In these patients, UVJO was found during RGP in the operating room. One of these patients had hydronephrosis with perirenal urinoma, but no dilation of the ureter, on the ultrasound examination performed before surgery (Fig. 1). The size of the urinoma had increased, and pyeloplasty was planned. During RGP, this patient was noted to have 444
ureteral narrowing at the UVJ and diffuse ureteral dilation. In the other 3 patients, ureteral dilation was either never or only occasionally found on their preoperative ultrasound evaluations. These patients displayed no evidence of vesicoureteral reflux (VUR) during voiding cystourethrography. The existence of UPJO was not diagnosed preoperatively in 1 patient, because a preoperative antegrade urinary tract evaluation was not performed. Preoperative ultrasonography revealed hydronephrosis grade III with diffuse ureter dilation. The DMSA scan revealed decreased DRF (35.3%) in the ipsilateral kidney; thus, UNC was planned, because it was assumed that this patient had only UVJO. After general anesthesia was induced, RGP was attempted but failed; the ureteral catheter could not pass through the ureteral orifice owing to severe angulation of the distal ureter at the UVJ. Plication UNC was performed, and temporary ureteral catheter placement was attempted during surgery; however, this also failed, because the ureteral catheter could not pass into the renal pelvis. RGP was attempted again, which was then successful. The results showed narrowing of the ureter at the UPJ, and pyeloplasty was immediately performed. Surgical Management and Outcomes The median age of the 15 patients who underwent pyeloplasty or UNC as their first operation was 5.0 months (interquartile range [IQR] 3.2-12.8). Pyeloplasty was the initial surgical approach in 9 patients, and UNC using the Starr technique for ureter plication10 was the initial surgery in 5 patients (Table 1). In the patient in whom UPJO was not diagnosed preoperatively, both pyeloplasty and plication UNC were performed simultaneously. During a median follow-up period of 39.3 months (IQR 15.3-60.2), an additional UNC or pyeloplasty was required in 4 patients (28.6%) of the 14 patients who had undergone initial pyeloplasty or UNC. Of the 5 patients with initial plication UNC, additional pyeloplasty was required in 2 patients. In another patient who had undergone initial plication UNC, pyeloplasty was planned because of residual postoperative hydronephrosis with decreased renal function. However, RGP revealed no obstruction at either the UPJ or previously operated UVJ; thus, pyeloplasty was not performed. Preoperative DRF was assessed at a median of 0.6 months (IQR 0.4-1.1) before the initial operation. Postoperative DRF was assessed in 13 patients at a median of 11.8 months (IQR 9.5-33.5) after the initial operation. The median preoperative and postoperative DRF value was 43.0 (IQR 37.0-47.0) and 39.0 (IQR 31.0-45.5), respectively. Of the 13 patients with both preoperative and postoperative DRF assessments, the DRF decreased by >5% in 7 patients (53.8%). A decreased DRF by >5% was observed in all 4 patients (100.0%) who had undergone initial UNC but in only 3 of the 9 patients (37.5%) who had undergone initial pyeloplasty. This difference did not reach statistical significance (P ¼ .081). Sex, kidney side (left or right), age at the initial operation, and preoperative UROLOGY 83 (2), 2014
UROLOGY 83 (2), 2014
Table 1. Demographics and characteristics of 15 patients
Pt. Initial Preoperative No. Sex Side Presentation Diagnosis
Preoperative Ultrasound Findings
Distal Age at Ureter Preoperative First Diameter Antegrade Operation (mm) Study (mo)
VUR on VCUG
First Operation
Age at Second Operation (mo)
Second Operation
Stasis at pelvis (MAG-3) Stasis at pelvis (MAG-3)
23.0
No
Pyeloplasty
—
—
2.1
No
Pyeloplasty
—
—
10.8
Stasis at pelvis (AGP)
109.1
No
Pyeloplasty
—
—
HN 3 without ureter dilation, urinoma HN 4 with occasional ureter dilation HN 4 with occasional ureter dilation HN 3 without ureter dilation
No dilation
Stasis at pelvis (MAG-3)
1.3
No
Pyeloplasty
—
—
7.2
Stasis at pelvis (MAG-3)
5.0
No
Pyeloplasty
—
—
7.1
Stasis at pelvis (MAG-3)
1.2
No
Pyeloplasty
—
No dilation
12.0
No
Pyeloplasty
—
HN 4 with diffuse ureter dilation HN 4 with diffuse ureter dilation
24.4
10.2
No
Pyeloplasty
16.7
UNC
14.1
No
Pyeloplasty
20.4
UNC
UPJO þ UVJO
HN 4 with diffuse ureter dilation
11.3
UPJO þ UVJO
HN 3 with diffuse ureter dilation
8.1
Stasis at pelvis, ureter (MAG-3) Stasis at pelvis (AGP) Stasis at pelvis, ureter (MAG-3) Stasis at pelvis, ureter (MAG-3) Stasis at pelvis, ureter (MAG-3)
1
M
R
Prenatal HN
UPJO þ UVJO
2
M
R
Prenatal HN
UPJO þ UVJO
3
F
R Re-current UTI
UPJO þ UVJO
HN 3 with diffuse ureter dilation
4
M
L
Prenatal HN, UTI
UPJO
5
M
L
Prenatal HN
UPJO
6
F
R Prenatal HN
UPJO
7
F
L
Prenatal HN
UPJO
8
M
L
Prenatal HN, UTI
UPJO þ UVJO
9
F
L
Prenatal HN
UPJO þ UVJO
10
F
R Prenatal HN, UTI
11
M
R Prenatal HN, UTI
HN 4 with diffuse ureter dilation HN 4 with diffuse ureter dilation
7.0 8.1
8.0
Preoperative DRF (%)
Postoperative Ultrasound Postoperative Findings DRF (%)
48 (MAG-3) HN 1 without ureter dilation 37 (MAG-3) HN 2 with ureter dilation (5.0 mm) 39 (DMSA) No HN with ureter dilation (7.0 mm) 47 (MAG-3) HN 2 without ureter dilation
N/A 36 (DMSA)
40 (DMSA)
48 (DMSA)
47 (MAG-3) HN 2 without ureter dilation
51 (MAG-3)
Ureteroscopic 43 (MAG-3) HN 2 with ureter stone dilation removal (4.7 mm) — 45 (MAG-3) HN 1 without ureter dilation
20 (DMSA)
45 (DMSA) HN 2 without ureter dilation 46 (MAG-3) HN 2 without ureter dilation
48 (DMSA)
31 (DMSA) 33 (DMSA)
4.5
Contralateral VUR
UNC
—
—
38 (MAG-3) HN 1 without ureter dilation
N/A
12.6
No
UNC
—
—
50 (MAG-3) HN 1 without ureter dilation
43 (MAG-3)
Continued
445
— — UNC þ pyeloplasty No NA 9.2
3.1
RGP 8.5 UNC No 4.6 Stasis at pelvis (MAG-3) 10.0
Pyeloplasty 18.2 UNC No 11.2 Stasis at pelvis (MAG-3) 7.3
UVJO Prenatal HN M 15
L
UPJO þ UVJO Prenatal HN M 14
L
UPJO þ UVJO Prenatal HN L M 13
AGP, antegrade pyeloureterography; DMSA, dimercaptosuccinic acid; DRF, differential renal function; F, female; HN, hydronephrosis; L, left; M, male; MAG-3, technetium-99m mercaptoacetyltriglycine; NA, not applicable; Pt. No., patient number; R, right; RGP, retrograde pyeloureterography; UNC, ureteroneocystostomy; UPJO, ureteropelvic junction obstruction; UTI, urinary tract infection; UVJO, ureterovesical junction obstruction; VCUG, voiding cystourethrography; VUR, voiding cystourethrography.
39 (DMSA)
20 (MAG-3)
31 (DMSA)
42 (DMSA)
HN 4 with ureter dilation (5.2 mm) 42 (MAG-3) HN 4 with ureter dilation (5.0 mm) 31 (MAG-3) HN 2 with ureter dilation (7.0 mm) 35 (MAG-3) HN 2 without ureter dilation 49 (MAG-3) Pyeloplasty 11.8 UNC No 5.0 Stasis at pelvis (MAG-3) 11.5
HN 4 with diffuse ureter dilation HN 3 with diffuse ureter dilation HN 4 with diffuse ureter dilation HN 3 with diffuse ureter dilation UPJO þ UVJO Prenatal HN L F
Pt. Initial Preoperative No. Sex Side Presentation Diagnosis
12
Postoperative Ultrasound Postoperative Findings DRF (%) Preoperative DRF (%) Second Operation VUR on VCUG
First Operation
Age at Second Operation (mo) Distal Age at Ureter Preoperative First Diameter Antegrade Operation (mm) Study (mo) Preoperative Ultrasound Findings Table 1. Continued
446
DRF did not significantly differ between the patients with and without a >5% decrease in DRF postoperatively.
COMMENT UPJO and UVJO are common causes of pediatric hydronephrosis. However, it is difficult to define ureteral “obstruction,” because ureteral obstruction and nonobstruction cannot be clearly differentiated.11 The most popular current definition of ureteral obstruction is that suggested by Koff12: “any restriction to urinary outflow that, if left untreated, will cause progressive renal deterioration.” Using this definition, DRF deterioration and progressive renal parenchymal thinning are considered important signs of UPJO and UVJO and provide an indication for surgery. Nevertheless, when UPJO and UVJO coexist, this definition leads to confusion in both diagnosis and management. When deteriorating renal function is encountered in this situation, it is difficult to know whether the deterioration has resulted from the UPJ or UVJ narrowing and which surgery would be most appropriate. A few reports have described the coexistence of UPJO and UVJO, and most of these studies have had difficulties in establishing the correct diagnosis. McGrath et al6 reported that the diagnosis of coexisting UPJO and UVJO was possible preoperatively in 3 (21.4%), intraoperatively in 3 (21.4%), and postoperatively in 8 (57.1%) of the 14 patients they described. The correct diagnosis was made preoperatively in 5 of 11 patients (45.4%) in the study by Pesce et al7 and in 5 of 14 patients (35.7%) in the report by Cay et al.8 In the present study, coexisting UPJO and UVJO was diagnosed preoperatively in 10 of 15 patients (66.7%). The correct preoperative diagnosis was possible when stasis of radionuclide or contrast material was present in the renal pelvis during an antegrade study (eg, MAG-3, antegrade pyeloureterography) combined with diffuse ureteral dilation on ultrasonography. Of the 5 patients without a correct preoperative diagnosis, ultrasonography revealed either no or only occasional ureter dilation in 4 patients, and an antegrade study was not performed in 1 patient. If one encounters occasional ureteral dilation on ultrasonography, along with an UPJO pattern on an antegrade study, the possibility of coexisting UVJO or VUR should be considered. Whether to perform a whole ureter evaluation with RGP before pyeloplasty has been a matter of debate. Cockrell and Hendren13 found unpredicted findings during RGP in 36 of 100 patients diagnosed with UPJO and evaluated with RGP before pyeloplasty. Tortuosity of the upper ureter and >1 area of narrowing were included in their unpredicted findings. In contrast, Rushton et al14 suggested not performing RGP before pyeloplasty because the possibility of a distal ureteral obstruction could be excluded by preoperative ultrasonography and diuretic renography. However, Moodley et al5 reported 2 cases of coexisting UPJO and UVJO that were diagnosed only after RGP evaluation. We noted the same phenomenon UROLOGY 83 (2), 2014
Figure 1. Preoperative ultrasound scan of a male patient performed 20 days after birth revealing left hydronephrosis with (A) perirenal urinoma but (B) no ureter dilation. (C) Retrograde pyeloureterography revealed narrowing at the ureterovesical junction and ureteropelvic junction with diffuse ureteral dilation. Although a 3F ureteral catheter could pass through the narrowed portion at the ureterovesical junction, it could not pass through the ureteropelvic junction. The patient underwent pyeloplasty as initial surgical treatment; (D) intravenous pyelography performed 22 months after surgery showed improved hydronephrosis and distal ureter dilatation. The pathologic features of ureterovesical junction could have been either ureterovesical junction obstruction or nonobstructed, nonrefluxing megaureter, which could not be differentiated in this patient.
in our 4 patients, who were diagnosed only with UPJO preoperatively. A preoperative RGP evaluation could be helpful to not only determine the exact location of the UPJ, but also assess the status of the distal ureter and the possibility of concurrent UVJO. Although retrograde UPJ evaluation using RGP is not always possible owing to either the difficulty of contrast passing through the UVJ or severe kinking of the distal ureter, it could reduce the possibility of a misdiagnosis of coexisting UPJO and UVJO when combined with a preoperative antegrade evaluation. Even after the diagnosis of coexisting UPJO and UVJO has been established, determining the first site for surgery is a remaining question. We performed simultaneous plication UNC and pyeloplasty in 1 patient. Although UROLOGY 83 (2), 2014
postoperative DRF recovery occurred in this patient, simultaneous procedures on the UPJ and UVJ are not generally recommended because of the potential negative effect on ureteral vascularity. Previous reports have recommended pyeloplasty as the initial surgical management for this group of patients. In the study by McGrath et al,6 all 6 patients with initial UNC required additional pyeloplasty, but only 2 of 5 patients with initial pyeloplasty required subsequent UNC. Pesce et al7 and Cay et al8 performed initial pyeloplasty, because the natural resolution rate of UVJO has been greater than that of UPJO. The possible existence of a nonobstructed, nonrefluxing megaureter requiring no operation could be another reason for initial pyeloplasty before UNC. Differentiating UVJO from a nonobstructed, nonrefluxing megaureter is 447
difficult. Although all dilated ureters do not always indicate the existence of ureteral obstruction, no reference standard method is available with which to differentiate one from the other.15 Only repeated investigations and comparing the changes in the variables have been recommended. Moreover, when coexisting with UPJO, antegrade studies often will not reveal the stasis at the ureter, and exact differentiation can be nearly impossible. Initial pyeloplasty and serial follow-up of the distal ureter might prevent unnecessary UNCs. The success rate of each operation could also be considered. The success rate of plication UNC using the Starr method is known to be around 93%-95%,16,17 and that of pyeloplasty is reported to be 95%-99%.14,18 Although a direct comparison between the different operations is difficult, the success rate of pyeloplasty seems to be greater. Nevertheless, we chose the operation according to the combined results of the antegrade and retrograde evaluations, except for the 1 patient without a preoperative antegrade study. We had 2 reasons for our decision to perform initial UNC in 5 patients. Although the natural resolution rate of UVJO has been greater than that of UPJO, resolution depends on the diameter of the ureter.19,20 For patients with severe ureteral dilation, we have considered performing UNC rather than pyeloplasty as the initial surgical management. The other reason was the possibility of spontaneous resolution of secondary UPJO after treatment of UVJO. Distal ureter pathologic entities, such as VUR and UVJO, is known to cause secondary UPJO.21 Although the pathophysiology has not been fully proven, ureter kinking, stretching of the renal pelvis causing atonicity, inflammation, and ureteritis have been suspected as causes of secondary UPJO from VUR.21,22 This might be similar in cases of secondary UPJO caused by UVJO, because UVJO could also be a cause of these conditions. However, whether resolution of the primary pathologic entity could resolve the secondary UPJO has not been firmly established. In cases of secondary UPJO caused by VUR, initial pyeloplasty has been suggested to be a better initial management modality than the correction of VUR.23 However, a recent report by Ebadi et al24 demonstrated resolution of UPJO after endoureterotomy for distal UVJO. In our study, only 2 of 5 patients with initial UNC required additional pyeloplasty. These cases have thus illustrated that initial pyeloplasty is not always the most appropriate first-line therapy. Nevertheless, whatever the initial surgery might be for patients with coexisting UPJO and UVJO, the possibility of requiring additional operations should be remembered. In our study, 28.6% of patients who had undergone initial pyeloplasty or initial UNC required an additional operation. In previous reports concerning coexisting UPJO and UVJO, the additional operation rate varied. In the report by Pesce et al,8 they performed initial pyeloplasty followed by UNC in all patients with coexisting UPJO and UVJO. In contrast, McGrath et al6 performed additional UNC in 40% of patients with initial pyeloplasty. A 448
report by Ebadi et al24 stated that only 6.4% of patients required additional pyeloplasty after initial endoureterotomy for UVJO. The wide range of additional operation rates has revealed the difficulty of treating coexisting UPJO and UVJO, even after the initial operation. It is often difficult to decide whether and where to operate when persistent hydronephrosis with decreased DRF after initial pyeloplasty or UNC has been encountered. DRF has been criticized for its poor correlation with renal histologic changes and low predictive potential for future renal function.25 Moreover, even if the DRF is correct, it is still challenging to differentiate delayed recovery or failure of the previous operation from aggravation of the obstruction that has not been treated. The present study had certain limitations. For example, the retrospective design of the study led to the potential for selection bias. Moreover, we diagnosed coexisting UPJO and UVJO and then decided where to operate using the combined results of the antegrade and retrograde evaluations. This decision could have had an element of subjectivity. In particular, although megaureter is considered present when the diameter of a ureter is >7-8 mm, it was not considered present in 4 patients whose UVJO was diagnosed during the RGP evaluation. Although we found prominent ureteral dilation in RGP, we did not measure the exact diameter during the procedure. In 2 patients with a percutaneous nephrostomy tube, a pressure flow study such as the Whitaker test would have been more helpful in making the diagnosis, if performed. In addition, postoperative radioisotope imaging in the present study was mostly DMSA scanning, and MAG-3 scans were taken preoperatively. We preferred a postoperative evaluation with DMSA scan and intravenous pyeloureterography, rather than the MAG-3 scan, for patients with coexisting UPJO and UVJO. It was helpful to visualize the whole ureter at a glance and to get information on the DRF. The evaluation of transit time with the MAG-3 scan is widely known to be inaccurate.26 Nevertheless, if we could compare the half-life of the tracer postoperatively with that from a preoperative study, it would have been helpful. Finally, the number of patients was small, and the type of initial operation was not controlled. Additional larger, controlled studies should provide more definitive information for determining whether pyeloplasty or UNC is the most appropriate initial surgery.
CONCLUSION It is difficult to correctly diagnose coexisting UPJO and UVJO. Before pyeloplasty in patients with UPJO, RGP is strongly recommended to assess both the distal ureter and the UVJ. Initial pyeloplasty should not always be recommended as the first-line therapy, because of the possibility of secondary UPJO caused by UVJO. References 1. Lebowitz RL, Griscom NT. Neonatal hydronephrosis: 146 cases. Radiol Clin North Am. 1977;15:49-59.
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2. Brown T, Mandell J, Lebowitz RL. Neonatal hydronephrosis in the era of sonography. AJR Am J Roentgenol. 1987;148:959-963. 3. O’Reilly PH, Brooman PJ, Mak S, et al. The long-term results of Anderson-Hynes pyeloplasty. BJU Int. 2001;87:287-289. 4. DeFoor W, Minevich E, Reddy P, et al. Results of tapered ureteral reimplantation for primary megaureter: extravesical versus intravesical approach. J Urol. 2004;172:1640-1643; discussion 1643. 5. Moodley P, Demaria J, Lorenzo AJ, et al. Concurrent ureteropelvic and ureterovesical junction obstruction in children: the value of retrograde pyelography. J Pediatr Urol. 2010;6:117-121. 6. McGrath MA, Estroff J, Lebowitz RL. The coexistence of obstruction at the ureteropelvic and ureterovesical junctions. AJR Am J Roentgenol. 1987;149:403-406. 7. Pesce C, Musi L, Campobasso P, et al. Coexisting pelviureteral and vesicoureteral junction obstruction in children. Eur J Pediatr Surg. 2003;13:367-371. 8. Cay A, Imamoglu M, Bahat E, et al. Diagnostic difficulties in children with coexisting pelvi-ureteric and vesico-ureteric junction obstruction. BJU Int. 2006;98:177-182. 9. Fernbach SK, Maizels M, Conway JJ. Ultrasound grading of hydronephrosis: introduction to the system used by the Society for Fetal Urology. Pediatr Radiol. 1993;23:478-480. 10. Starr A. Ureteral plication: a new concept in ureteral tailoring for megaureter. Invest Urol. 1979;17:153-158. 11. Tekgül S, Riedmiller H, Dogan H, et al. Dilation of the upper urinary tract (ureteropelvic junction and ureterovesical junction obstruction). In: Guidelines on Paediatric Urology. European Association of Urology; European Society for Paediatric Urology; Arnheim, The Netherlands: European Association of Urology; 2013;13:61-64. 12. Koff SA. Problematic ureteropelvic junction obstruction. J Urol. 1987;138:390. 13. Cockrell SN, Hendren WH. The importance of visualizing the ureter before performing a pyeloplasty. J Urol. 1990;144:588-592; discussion 584-593. 14. Rushton HG, Salem Y, Belman AB, et al. Pediatric pyeloplasty: is routine retrograde pyelography necessary? J Urol. 1994;152:604-606. 15. Shokeir AA, Nijman RJ. Primary megaureter: current trends in diagnosis and treatment. BJU Int. 2000;86:861-868. 16. Perdzynski W, Kalicinski ZH. Long-term results after megaureter folding in children. J Pediatr Surg. 1996;31:1211-1217. 17. Parrott TS, Woodard JR, Wolpert JJ. Ureteral tailoring: a comparison of wedge resection with infolding. J Urol. 1990;144:328-329. 18. Woo HH, Farnsworth RH. Dismembered pyeloplasty in infants under the age of 12 months. Br J Urol. 1996;77:449-451. 19. Ranawaka R, Hennayake S. Resolution of primary non-refluxing megaureter: an observational study. J Pediatr Surg. 2013;48:380-383. 20. McLellan DL, Retik AB, Bauer SB, et al. Rate and predictors of spontaneous resolution of prenatally diagnosed primary nonrefluxing megaureter. J Urol. 2002;168:2177-2180; discussion 2180. 21. Wein AJ, Kavoussi LR, Campbell MF, eds. Campbell-Walsh Urology, 10th ed. Philadelphia: Elsevier Saunders; 2012. 22. Whitaker RH. Methods of assessing obstruction in dilated ureters. Br J Urol. 1973;45:15-22. 23. Lebowitz RL, Blickman JG. The coexistence of ureteropelvic junction obstruction and reflux. AJR Am J Roentgenol. 1983;140:231-238. 24. Ebadi M, Kajbafzadeh AM, Tourchi A, et al. Endoureterotomy as the initial management of concurrent ureteropelvic and ureterovesical junction obstruction after failed conservative therapy. Urology. 2013;82:214-219. 25. Elder JS, Stansbrey R, Dahms BB, et al. Renal histological changes secondary to ureteropelvic junction obstruction. J Urol. 1995;154: 719-722. 26. Gearhart JP, Rink RC, Mouriquand PDE. Pediatric Urology, 2nd ed. Philadelphia: Elsevier; 2010.
hydronephrosis still is a puzzling situation, because we lack reliable standards for evaluation and indications for surgery. Rarely, do UVJO and UPJO coexist, although radiologic evaluation findings might suggest otherwise. The authors, using Society for Pediatric Urology criteria, categorized all patients in this series as having grade 3 or 4 hydronephrosis, groups more likely to undergo surgery. All were investigated because of the finding of antenatal hydronephrosis, except for 1 older, symptomatic child. Experience has shown that many cases of hydronephrosis diagnosed in asymptomatic neonates improve or resolve during observation. In patients with presumed megaureter, in particular, we have learned that with watchful waiting, especially when the ureteral diameters are 1.2 cm. Of these 5, 80% were 1.2 cm in diameter; hence, the issue of a “surgical megaureter” must be questioned. Additionally, 3 patients underwent lower ureteral surgery, despite minimal or no dilation, but because of difficulty inserting ureteral catheter and/or some dilation found on the retrograde pyelogram. As objective as we try to be, the subjective bias of a surgeon can be great, not to mention parental angst and cultural influence, and all these come into play in decision making. The dilemma becomes even more substantial, when additional tests, especially when they are primarily anatomic, suggest >1 potential “surgically correctable” entity might be present. In our practice of 5 experienced surgeons, we have routine disagreements regarding when retrograde pyelography is indicated in patients undergoing pyeloplasty for UPJO or lower ureteral surgery for megaureter. Some of our group believe that retrograde pyelography is indicated for all such patients. Others of us believe instrumentation in straightforward cases can be meddlesome because it can potentially traumatize the ureteral orifice and could open a Pandora’s box by uncovering a minor issue that might be construed as significant. Many of us still fall into the trap of equating bad appearance with bad function. This speaks to the point that judgment is required in each individual case to identify those anatomic curiosities that have a potential physiologic effect. We lack a single reference standard study that can define when intervention is necessary, especially when so many cases of hydronephrosis and/or hydorureteronephrosis are transient rather than pathologic in nature. Martin A. Koyle, M.D., Section of Pediatric Urology, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada http://dx.doi.org/10.1016/j.urology.2013.08.089 UROLOGY 83: 449, 2014. 2014 Elsevier Inc.
REPLY EDITORIAL COMMENT Although this report asks a perplexing question, I am still uncertain that a definitive answer is forthcoming. Significant UROLOGY 83 (2), 2014
Because the rate of spontaneous remission is high, most primary megaureters require no surgical intervention. Surgical management has been indicated only for patients with recurrent urinary 449
tract infection, a decrease in the DRF, and significant obstruction.1 The degree of hydronephrosis and the diameter of ureter have been known to affect the natural resolution rate. McLellan et al2 reported that a megaureter with diameter >10 mm might require surgical management. Recently, Ranawaka and Hennayake3 reported the natural resolution rate of patients with megaureter by classifying them into groups according to the ureter diameter. In their study, 1 group with a ureter diameter of 10 mm, had a resolution rate of only 17%. The indications for operation and the natural resolution rate relating to the ureter diameter were similar in our institution. In this study, however, the preoperative ureter diameter measured on ultrasonography was not its real diameter owing to the coexisting UPJO. Preoperative ultrasonography revealed no or occasional ureter dilation in 4 patients and RGP showed prominent ureter dilation. Even in the other 11 patients, preoperative ultrasonography might have underestimated the ureter diameter owing to the obstruction effect at the UPJ. It is also the reason for plication during megaureter correction. We usually perform plication ureteroneocystostomy when the ureter diameter is >10 mm. Although the preoperative ureter diameter measured on ultrasonography was not >10 mm in most patients, RGP revealed severe dilation, and plication was performed during the surgery. RGP before pyeloplasty has been recommended generally, because it can evaluate the entire ureter.4,5 Confirming the diagnosis, demonstrating the exact site and shape of the obstruction, and showing unpredicted abnormal anatomic findings before repair can be helpful. We agree, however, with the editorial comment that the potential for trauma to the ureteral
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orifice during the procedure exists. It should be performed with care, especially in neonates and infants. Although many reports have been published concerning pediatric ureteral obstruction, most of them focused on the technical aspects of the operation. This particular field still has questions that need to be answered. The development of new biomarkers to exactly assess the kidney injury and advanced functional imaging studies would be helpful. Yong Seung Lee, M.D., Rosito T. Bascuna, Jr, M.D., Hyeyoung Lee, M.D., Young Jae Im, M.D., and Sang Won Han, M.D., Department of Urology and Urological Science Institute, Yonsei University College of Medicine, Seoul, Korea
References 1. Tekgül S, Riedmiller H, Dogan H, et al. Dilation of the upper urinary tract (ureteropelvic junction and ureterovesical junction obstruction). In: Guidelines on Paediatric Urology. European Association of Urology; European Society for Paediatric Urology; Arnheim, The Netherlands: European Association of Urology; 2013;13:61-64. 2. McLellan DL, Retik AB, Bauer SB, et al. Rate and predictors of spontaneous resolution of prenatally diagnosed primary nonrefluxing megaureter. J Urol. 2002;168:2177-2180; discussion 2180. 3. Ranawaka R, Hennayake S. Resolution of primary non-refluxing megaureter: an observational study. J Pediatr Surg. 2013;48:380-383. 4. Wein AJ, Kavoussi LR, Campbell MF, eds. Campbell-Walsh Urology, 10th ed. Philadelphia: Elsevier Saunders; 2012. 5. Gearhart JP, Rink RC, Mouriquand PDE. Pediatric Urology, 2nd ed. Philadelphia: Elsevier; 2010.
http://dx.doi.org/10.1016/j.urology.2013.08.090 UROLOGY 83: 449e450, 2014. 2014 Elsevier Inc.
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