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Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases
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Journal of Pediatric Urology (2015) xx, 1.e1e1.e5
Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases Department of Pediatric Surgery, The 2nd Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China Correspondence to: C.-D. Chen, Department of Pediatric Surgery, The 2nd Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China, Tel.: þ86 577 88002827; fax: þ86 577 88338873 [email protected] (L.N. Dai) [email protected] (C.D. Chen) [email protected] (X.K. Lin) [email protected] (Y.B. Wang) [email protected] (L.G. Xia) [email protected] (P. Liu) [email protected] (X.M. Chen) [email protected] (Z.R. Li) Keywords Hydronephrosis; Ureteral fibroepithelial polyp; Retroperitoneoscopy; Pediatric Received 22 November 2014 Accepted 15 February 2015 Available online xxx
L.N. Dai, C.D. Chen, X.K. Lin, Y.B. Wang, L.G. Xia, P. Liu, X.M. Chen, Z.R. Li Summary Introduction Hydronephrosis is a common disease in children and may be caused by ureteral fibroepithelial polyps (UFP). Ureteral fibroepithelial polyps are rare in children and are difficult to precisely diagnose before surgery. Surgical treatment for symptomatic UFP is recommended. At the present institution, retroperitoneal laparoscopy has been used to treat five boys with UFP since 2006. Objective To highlight the significance of UFP as an etiological factor of hydronephrosis in children and evaluate the applicative value of retroperitoneal laparoscopy in the treatment of children with UFP. Methods Between 2006 and 2013 five boys underwent retroperitoneal laparoscopy at the present institution. They were identified with UFP by review of the clinical database. Detailed data were collected, including: radiographic studies, gross anatomical pathology, and pathology and radiology reports. All boys had been followed up at least every 6 months. Results All of the boys were aged between 7 and 16 years (mean 9.8 years). The main symptoms were flank
Figure
pain (all five) and hematuria (three). Radiographic examination showed that all of the boys presented with incomplete ureteral obstruction and hydronephrosis. The ureteral fibroepithelial polyps were located near the left UPJ or the left proximal ureter. All of the boys had the UFP removed: three underwent retroperitoneal laparoscopic dismembered AndersoneHynes pyeloplasty and polypectomy, and two had retroperitoneal laparoscopic ureteral anastomosis. These polyps were all on the left side and between 15 and 35 mm in length (mean 22 mm) (Figure). All of the boys recovered well and were discharged from hospital. The postoperative histological report confirmed that the specimens were UFP. Hydronephrosis was periodically assessed by ultrasonography (using the same method as pre-surgical ultrasonography) after surgery. Mean follow-up was 33 months (range 6e58 months) and no complications were found afterwards. Conclusions Ureteral fibroepithelial polyps are rare but rather important as they can cause UPJ obstruction, which often manifests as hydronephrosis. It is most important to confirm the site of ureteral obstruction before surgery as this may have an effect on the surgical management. It is recommended that UFP be successfully managed in children with retroperitoneal laparoscopy.
Intraoperative findings of ureteral fibroepithelial polyps and the gross samples.
http://dx.doi.org/10.1016/j.jpurol.2015.02.019 1477-5131/ª 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Dai LN, et al., Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.02.019
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L.N. Dai et al.
Introduction Hydronephrosis is a common disease in children and is usually caused by congenital factors such as UPJ stenosis and blood vessel aberration [1,2]. Ureteral fibroepithelial polyps (UFP), which may contribute to hydronephrosis, are a rare cause of UPJ obstruction (UPJO) in children. The symptoms are mainly hematuria and flank pain, which are secondary to obstruction [3,4]. Ureteral fibroepithelial polyps are difficult to precisely diagnose before surgery; this has been reported to be as low as 22% [5]. Therefore, UFP should be regarded as the etiological factor of hydronephrosis in children. To better understand UFP in children, five pathologically proven cases were reviewed. All cases in the series had undergone retroperitoneoscopy. Their clinical features were summarized and analyzed to help improve the diagnosis and evaluate the value of retroperitoneoscopy, these included: symptoms, imaging examinations, intraoperative findings, histopathological examinations and follow-ups.
Materials and methods Materials The present study was based on data from five pathologically proven cases between 2006 and 2013 from the archives of the present institution. The data included radiologic images, intraoperative and gross photographs, and pathologic reports. All of the boys underwent ultrasonography (US) and intravenous urography (IVU), in which computed tomographic (CT) imaging was performed in three cases, and one underwent magnetic resonance urethrography (MRU) with three-dimensional (3D) reconstruction. Every case was categorized by: age, sex, clinical presentation and location, gross findings, polyp size, margins and comorbid diseases (Table 1). Five boys, as reported, were highly suspected as having UFP preoperatively and intraoperative findings confirmed the diagnosis.
Surgical procedure After general anesthesia and intubation, five boys underwent retroperitoneoscopy and had the UFP removed. The boys were placed in the lateral decubitus position, tilting
Table 1
forward 45 degrees. A 2-cm incision was first made at the midpoint between the 12th rib and the iliac crest on the posterior axillary line. After a working space was created in the retroperitoneum by balloon dissector, a 5-mm blunt-tip trocar (camera port) was placed. The pneumoretroperitoneum was established at a pressure of 12 mmHg. A second 5-mm trocar was placed on the anterior axillary line. A third 5-mm trocar was placed on the middle axillary line at the level of the iliac crest. The lateroconal fascia was incised along the quadratus lumborum muscle, which allowed for exposure of the psoas muscle and the posterior lamina of Gerota’s fascia. For each case, the initial finding was a dilated renal pelvis; the UPJ was then found and explored downwards along the ureter. Polyps were lobulated, aquatic-plant-like masses, growing upwards along the ureter, where their pedicles were located. If the roots of the polyps were adjacent to the UPJ (often within 2 cm) a retroperitoneal laparoscopic dismembered AndersoneHynes pyeloplasty was performed. Otherwise, a segment of the UFP roots was slantingly resected and anastomosed under retroperitoneoscopy. The renal pelvis was anastomosed and the ureter was spatulated using 5-0 VICRYL Plus interrupted sutures. At completion of the procedure a proper double-J stent was left in place for 6 weeks.
Follow-up All boys had an uneventful recovery and were discharged from hospital 5 days after the procedure. The double-J stent was removed by cystoscopy. The boys had follow-ups for at least 6 months. Urinalysis and US were tested monthly during the follow-up period, and emission CT was performed 6 months after the operations.
Results The boys’ ages ranged from 7 to 16 years, with a mean age of 9.8 years; all were male. The main symptoms were flank pain (all five) and hematuria (three). All boys had hydronephrosis prior to surgery. Pre-operative evaluation of all boys included: US and IVU (Fig. 1); three also had CT scans and one had an MRU (with 3D reconstruction) (Fig. 2). All five boys in the series were highly suspected as having UFP preoperatively and underwent retroperitoneoscopy. This
Clinical characteristics of five boys with ureteral fibroepithelial polyps.
Patient Age Sex Presentation no. (years) 1
16
M
2 3 4
7 7 10
M M M
5
9
M
Location
Flank pain, hematuria Left proximal ureter Flank pain, hematuria Left UPJ Recurrent flank pain Left UPJ Flank pain. hematuria Left proximal ureter Recurrent flank pain Left proximal ureter
Gross findings
Size (mm)
Margin
Comorbid condition
Multiple polyps
30
Smooth
Hydronephrosis
2 filiform polyps 35 2/20 2 Smooth Filiform 10 2 Smooth Fine columer polyp 15 Mildly irregular 3 filiform polyps 22 Smooth
Renal cyst Hydronephrosis Hydronephrosis Hydronephrosis
UPJ, ureteropelvic junction.
Please cite this article in press as: Dai LN, et al., Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.02.019
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Retroperitoneal laparoscopy management for ureteral fibroepithelial
Figure 3 Figure 1 Intravenous urography showing left-sided hydronephrosis and a filling defect at the proximal ureter (arrow).
diagnosis was confirmed by intraoperative findings (Fig. 3). Fibroepithelial polyps and inflammatory cell infiltration were confirmed by postoperative histopathological findings and were in accordance with intraoperative findings (Fig. 4). The mean follow-up period was 33 months (range 6e58 months). No UTIs were observed, and US (using the same method as the pre-surgical US) revealed decreased renal pelvis dilation in all cases. After 6 months, the emission CT showed no obstructive pattern, and split renal function was improved.
Discussion Tumors of the ureter are extremely rare in children. Ureteral fibroepithelial polyps are a type of tumor of mesodermal origin and comprise 20% of all ureteric tumors. Approximately 50e60% of UFP are located in the upper ureter or UPJ. Most of UFP that often occur on the left side are found more frequently in males than in females. In a study of 1710 cases of pyeloplasty for UPJO in children, fibroepithelial polyps were found in only nine cases.
Figure 2 Magnetic resonance urethrography revealing soft tissue filling in the UPJ and hydronephrosis; the renal cyst is clearly displayed.
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Intraoperative findings of FEPs (arrows).
UPJ obstruction is a very common cause of pediatric hydronephrosis and UFP can be an extremely rare etiology of that [5,6]. However, UFP must be recognized as an important etiology for hydronephrosis in children. The clinical presentation of UPJO caused by UFP is the same as those by other causes of UPJO, with intermittent lumbar pain or flank pain and hematuria being the most common [7e11]. Symptoms can be present for several years before the diagnosis, while other patients with UFP may be asymptomatic and may not be diagnosed throughout of their lives [12]. Ureteral fibroepithelial polyps can occur at any age e from newborns to adults older than 70 years of age [13,14]. The most common age is 6e12 years, and the majority of the children reported in the literature were school age, which is similar to the present series with male predominance [8e11]. Ureteral fibroepithelial polyps occur more frequently on the left side and are often located in the UPJ and upper ureter, which is consistent with the present series. Pre-operative diagnosis of UFP can be difficult to make. The most effective way of currently diagnosing it is by imaging examination. Ultrasound always shows dilatation of the renal pelvis and part of the ureter, but is considered to be not that accurate. In the present series, US confirmed only one boy. Wang et al. reported their experience of utilizing US for the diagnosis of 35 pediatric UFP. They
Figure 4 Histological examination shows that the polyp is composed of a fibrous core covered by normal urothelium with inflammatory cell infiltration.
Please cite this article in press as: Dai LN, et al., Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.02.019
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1.e4 thought that UFP could be visualized with US, and their US accuracy rate reached 62.2%, which was higher than IVU (24.3%) [11]. However, some studies have found that IVU is a more sensitive means of diagnosing UFP over US or a nuclear medicine renal excretory study [5]. Radojicic et al. advised that retrograde pyelography or ureteroscopy might be required to differentiate UFP from other causes of UPJ or ureteric obstruction [16]. All boys in the present series underwent IVU and showed typical filling defects after IVU confirmed fibroepithelial polyps. But in some special cases that are associated with other diseases of the relevant systems, CT and MRU might be supplemental tests. Surgical treatment for symptomatic UFP is recommended. Laparoscopic surgery is initially considered because laparoscopic pyeloplasty has been performed for UPJO in children. The UFP have been found to have an aquatic-plant-like appearance, growing upwards along the ureter, but the pedicles were actually located in the upper ureter. UPJ obstruction, displayed by radiographic examinations, has been due to the floating ends of polyps e the longest of which was almost 35 mm in length. Pre-operative diagnosis of UFP is difficult to make, and the aquatic-plantlike polyps make it even harder to decide where to cut. In the present series, when UPJ was opened, the end of polyps could be seen, the pedicles of which were located in the distal ureter. Therefore, it was thought that if UFP were considered before surgery, the UPJ should not be transversely cut; otherwise, the ureter might be too short to anastomose after the segment of ureteral area containing the pedicles has been excised. If the ureter is opened longitudinally, and the distance from the pedicles to the UPJ is shorter than 2 cm, pyeloplasty might be feasible. If the distance exceeds 2 cm, it is difficult to perform anastomosis after removal of too much ureter. Therefore, the UPJ site containing the polyp must be removed and the edge of the renal pelvis and the spatulate ureter anastomosed. In these five cases, the roots of the polyps were observed by retroperitoneal laparoscopy and they were completely removed during a laparoscopic procedure. Laparoscopic surgery could be one of the options for minimally invasive treatment for children and to achieve complete resection of the polyp at the UPJ. Endoscopic management has been reported in previous literature. If the polyps are ureterscopically removed, a close follow-up is important to avoid possible recurrence. In 1998, there was a 16-year-old boy diagnosed with UFP recurrence who had ever been treated with endoscopy and holmium laser ablation. This case confirmed that endoscopic management might cause some possible recurrence. When retroperitoneoscopy was not carried out in the present institution (before 2003), the recurrence of a single polyp at the same location was found at 6-month follow-up and was ultimately resolved by open surgery rather than by endoscopy and holmium laser ablation. The etiology of UFP remains unknown and much speculation has suggested that it may be a congenital developmental defect or as a result of chronic irritation, calculi, infectious inflammation, allergic factors, obstruction, trauma and hormonal disturbances [4,12,15,16]. Ureteral fibroepithelial polyps often have a fibrovascular core covered with normal transitional epithelial cells or present only with polyps or inflammatory cell infiltration. The UFP in the present series were
L.N. Dai et al. composed of a fibrous core covered by normal urothelium with inflammatory cell infiltration. Macroscopically, they resembled an aquatic plant.
Conclusion The results of this single-center retrospective series suggest that UFP should be recognized as an important etiology of hydronephrosis in children. Although it is difficult to make the diagnosis before surgery, US and radiological examination, especially IVU, may assist. Therefore, schoolaged children with a history of flank pain, hematuria, or both, hydronephrosis with soft-tissue in the UPJ or proximal ureter, must be highly suspected as having UFP preoperatively. Appropriate consideration of UFP in the differential diagnosis of a urothelial mass is important in surgical management. Retroperitoneoscopy can be one of the options of minimally invasive treatment for children and can achieve complete resection of the UFP. The two key points that must be remembered are: confirm the location of UFP by investigation and do not resect the ureter too short.
Conflict of interest None declared.
Funding None declared.
Ethical statement Informed consent was obtained from all subjects and a license from the ethical committee was also issued.
Acknowledgement We would like to thank our colleagues from the Department of Pediatric Surgery, the 2nd Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, for their assistance with data collection.
References [1] Boylu U, Oommen M, Lee BR, Thomas R. Ureteropelvic junction obstruction secondary to crossing vessels-to transpose or not? The robotic experience. J Urol 2009;181:1751e5. [2] Richstone L, Seideman CA, Reggio E, Bluebond-Langner R, Pinto PA, Trock B, et al. Pathologic findings in patients with ureteropelvic junction obstruction and crossing vessels. Urology 2009;73:716e9. [3] Zeman L, Dusek M, Lisy J, Moravek J, Rygl M, Stejskal J, et al. Multiple fibroepithelial polyps of the upper ureter in a 17year-old-boy e case report and review of the literature. Eur J Pediatr Surg 2003;14:358e61. [4] Menon P, Kakkar N, Rao KL. Antenatal hydronephrosis: ureteral polyp causing ureteropelvic junction obstruction. Eur J Pediatr Surg 2004;14:345e7.
Please cite this article in press as: Dai LN, et al., Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.02.019
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Retroperitoneal laparoscopy management for ureteral fibroepithelial [5] Adey GS, Vargas SO, Retik AB, Borer JG, Mandell J, Hendren WH, et al. Fibroepithelial polyps causing ureteropelvic junction obstruction in children. J Urol 2003;169:1834e6. [6] Kumar A, Das SK, Trivedi S, Dwivedi US, Singh PB. Genitourinary polyps: summary of the 10 year experiences of a single institute. Int Urol Nephrol 2008;40:901e7. [7] Cassar DE, Joseph VT, Scherwood W. Fibroepithelial polyps causing ureteropelvic junction obstruction in childrenda case report and review article. Eur J Pediatr Surg 2007;17: 142e6. [8] Iwatsuki S, Kojima Y, Mizuno K, Tozawa K, Kohri K, Hayashi Y. Laparoscopic management of fibroepithelial polyp causing ureteropelvic junction obstruction in a child. J Urol 2010;76: 146e8. [9] Romesburg JW, Stein RJ, Desai MM, Lagwinski N, Ross JH. Treatment of a child with bilateral ureteropelvic junction obstruction due to fibroepithelial polyps and review of the literature. J Urol 2009;73(4):929.e9e11. [10] Kojima Y, Lambert SM, Steixner BL, Laryngakis N, Casale P. Multiple metachronous fibroepithelial polyps in children. J Urol 2011;185:1053e7.
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[11] Wang XM, Jia LQ, Wang Y, Wang N. Utilizing ultrasonography in the diagnosis of pediatric fibroepithelial polyps causing ureteropelvic junction obstruction. Pediatr Radiol 2012;42: 1107e11. [12] Kara C, Res‚orlu B, Oguz U, Unsal A. Incidentally detected ureteral fibroepithelial polyps in children: is endoscopic treatment of them really necessary? Int Urol Nephrol 2010;42: 1e5. [13] Williams TR, Wagner BJ, Corse WR, Vestevich JC. Fibroepithelial polyps of the urinary tract. Abdom Imaging 2002;27: 217e21. [14] Childs MA, Umbreit EC, Krambeck AE, Sebo TJ, Patterson DE, Gettman MT. Fibroepithelial polyps of the ureter: a singleinstitutional experience. J Endourol 2009;23:1415e9. [15] Niu ZB, Yang Y, Hou Y, Chen H, Wang CL. Ureteral polyps: an etiological factor of hydronephrosis in children that should not be ignored. Pediatr Surg Int 2007;23:323e6. [16] Radojicic Z, Basta-Jovanovic G, Dimitrijevic I, RadojevicSkodric S, Arsic D, Kalezic N, et al. Fibroepithelial polyp of the upper third of ureter. ANZ J Surg 2008;78:718.
Please cite this article in press as: Dai LN, et al., Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.02.019
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Journal of Pediatric Urology (2015) xx, 1.e1e1.e5
Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases Department of Pediatric Surgery, The 2nd Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China Correspondence to: C.-D. Chen, Department of Pediatric Surgery, The 2nd Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, Wenzhou, China, Tel.: þ86 577 88002827; fax: þ86 577 88338873 [email protected] (L.N. Dai) [email protected] (C.D. Chen) [email protected] (X.K. Lin) [email protected] (Y.B. Wang) [email protected] (L.G. Xia) [email protected] (P. Liu) [email protected] (X.M. Chen) [email protected] (Z.R. Li) Keywords Hydronephrosis; Ureteral fibroepithelial polyp; Retroperitoneoscopy; Pediatric Received 22 November 2014 Accepted 15 February 2015 Available online xxx
L.N. Dai, C.D. Chen, X.K. Lin, Y.B. Wang, L.G. Xia, P. Liu, X.M. Chen, Z.R. Li Summary Introduction Hydronephrosis is a common disease in children and may be caused by ureteral fibroepithelial polyps (UFP). Ureteral fibroepithelial polyps are rare in children and are difficult to precisely diagnose before surgery. Surgical treatment for symptomatic UFP is recommended. At the present institution, retroperitoneal laparoscopy has been used to treat five boys with UFP since 2006. Objective To highlight the significance of UFP as an etiological factor of hydronephrosis in children and evaluate the applicative value of retroperitoneal laparoscopy in the treatment of children with UFP. Methods Between 2006 and 2013 five boys underwent retroperitoneal laparoscopy at the present institution. They were identified with UFP by review of the clinical database. Detailed data were collected, including: radiographic studies, gross anatomical pathology, and pathology and radiology reports. All boys had been followed up at least every 6 months. Results All of the boys were aged between 7 and 16 years (mean 9.8 years). The main symptoms were flank
Figure
pain (all five) and hematuria (three). Radiographic examination showed that all of the boys presented with incomplete ureteral obstruction and hydronephrosis. The ureteral fibroepithelial polyps were located near the left UPJ or the left proximal ureter. All of the boys had the UFP removed: three underwent retroperitoneal laparoscopic dismembered AndersoneHynes pyeloplasty and polypectomy, and two had retroperitoneal laparoscopic ureteral anastomosis. These polyps were all on the left side and between 15 and 35 mm in length (mean 22 mm) (Figure). All of the boys recovered well and were discharged from hospital. The postoperative histological report confirmed that the specimens were UFP. Hydronephrosis was periodically assessed by ultrasonography (using the same method as pre-surgical ultrasonography) after surgery. Mean follow-up was 33 months (range 6e58 months) and no complications were found afterwards. Conclusions Ureteral fibroepithelial polyps are rare but rather important as they can cause UPJ obstruction, which often manifests as hydronephrosis. It is most important to confirm the site of ureteral obstruction before surgery as this may have an effect on the surgical management. It is recommended that UFP be successfully managed in children with retroperitoneal laparoscopy.
Intraoperative findings of ureteral fibroepithelial polyps and the gross samples.
http://dx.doi.org/10.1016/j.jpurol.2015.02.019 1477-5131/ª 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Dai LN, et al., Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.02.019
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L.N. Dai et al.
Introduction Hydronephrosis is a common disease in children and is usually caused by congenital factors such as UPJ stenosis and blood vessel aberration [1,2]. Ureteral fibroepithelial polyps (UFP), which may contribute to hydronephrosis, are a rare cause of UPJ obstruction (UPJO) in children. The symptoms are mainly hematuria and flank pain, which are secondary to obstruction [3,4]. Ureteral fibroepithelial polyps are difficult to precisely diagnose before surgery; this has been reported to be as low as 22% [5]. Therefore, UFP should be regarded as the etiological factor of hydronephrosis in children. To better understand UFP in children, five pathologically proven cases were reviewed. All cases in the series had undergone retroperitoneoscopy. Their clinical features were summarized and analyzed to help improve the diagnosis and evaluate the value of retroperitoneoscopy, these included: symptoms, imaging examinations, intraoperative findings, histopathological examinations and follow-ups.
Materials and methods Materials The present study was based on data from five pathologically proven cases between 2006 and 2013 from the archives of the present institution. The data included radiologic images, intraoperative and gross photographs, and pathologic reports. All of the boys underwent ultrasonography (US) and intravenous urography (IVU), in which computed tomographic (CT) imaging was performed in three cases, and one underwent magnetic resonance urethrography (MRU) with three-dimensional (3D) reconstruction. Every case was categorized by: age, sex, clinical presentation and location, gross findings, polyp size, margins and comorbid diseases (Table 1). Five boys, as reported, were highly suspected as having UFP preoperatively and intraoperative findings confirmed the diagnosis.
Surgical procedure After general anesthesia and intubation, five boys underwent retroperitoneoscopy and had the UFP removed. The boys were placed in the lateral decubitus position, tilting
Table 1
forward 45 degrees. A 2-cm incision was first made at the midpoint between the 12th rib and the iliac crest on the posterior axillary line. After a working space was created in the retroperitoneum by balloon dissector, a 5-mm blunt-tip trocar (camera port) was placed. The pneumoretroperitoneum was established at a pressure of 12 mmHg. A second 5-mm trocar was placed on the anterior axillary line. A third 5-mm trocar was placed on the middle axillary line at the level of the iliac crest. The lateroconal fascia was incised along the quadratus lumborum muscle, which allowed for exposure of the psoas muscle and the posterior lamina of Gerota’s fascia. For each case, the initial finding was a dilated renal pelvis; the UPJ was then found and explored downwards along the ureter. Polyps were lobulated, aquatic-plant-like masses, growing upwards along the ureter, where their pedicles were located. If the roots of the polyps were adjacent to the UPJ (often within 2 cm) a retroperitoneal laparoscopic dismembered AndersoneHynes pyeloplasty was performed. Otherwise, a segment of the UFP roots was slantingly resected and anastomosed under retroperitoneoscopy. The renal pelvis was anastomosed and the ureter was spatulated using 5-0 VICRYL Plus interrupted sutures. At completion of the procedure a proper double-J stent was left in place for 6 weeks.
Follow-up All boys had an uneventful recovery and were discharged from hospital 5 days after the procedure. The double-J stent was removed by cystoscopy. The boys had follow-ups for at least 6 months. Urinalysis and US were tested monthly during the follow-up period, and emission CT was performed 6 months after the operations.
Results The boys’ ages ranged from 7 to 16 years, with a mean age of 9.8 years; all were male. The main symptoms were flank pain (all five) and hematuria (three). All boys had hydronephrosis prior to surgery. Pre-operative evaluation of all boys included: US and IVU (Fig. 1); three also had CT scans and one had an MRU (with 3D reconstruction) (Fig. 2). All five boys in the series were highly suspected as having UFP preoperatively and underwent retroperitoneoscopy. This
Clinical characteristics of five boys with ureteral fibroepithelial polyps.
Patient Age Sex Presentation no. (years) 1
16
M
2 3 4
7 7 10
M M M
5
9
M
Location
Flank pain, hematuria Left proximal ureter Flank pain, hematuria Left UPJ Recurrent flank pain Left UPJ Flank pain. hematuria Left proximal ureter Recurrent flank pain Left proximal ureter
Gross findings
Size (mm)
Margin
Comorbid condition
Multiple polyps
30
Smooth
Hydronephrosis
2 filiform polyps 35 2/20 2 Smooth Filiform 10 2 Smooth Fine columer polyp 15 Mildly irregular 3 filiform polyps 22 Smooth
Renal cyst Hydronephrosis Hydronephrosis Hydronephrosis
UPJ, ureteropelvic junction.
Please cite this article in press as: Dai LN, et al., Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.02.019
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Retroperitoneal laparoscopy management for ureteral fibroepithelial
Figure 3 Figure 1 Intravenous urography showing left-sided hydronephrosis and a filling defect at the proximal ureter (arrow).
diagnosis was confirmed by intraoperative findings (Fig. 3). Fibroepithelial polyps and inflammatory cell infiltration were confirmed by postoperative histopathological findings and were in accordance with intraoperative findings (Fig. 4). The mean follow-up period was 33 months (range 6e58 months). No UTIs were observed, and US (using the same method as the pre-surgical US) revealed decreased renal pelvis dilation in all cases. After 6 months, the emission CT showed no obstructive pattern, and split renal function was improved.
Discussion Tumors of the ureter are extremely rare in children. Ureteral fibroepithelial polyps are a type of tumor of mesodermal origin and comprise 20% of all ureteric tumors. Approximately 50e60% of UFP are located in the upper ureter or UPJ. Most of UFP that often occur on the left side are found more frequently in males than in females. In a study of 1710 cases of pyeloplasty for UPJO in children, fibroepithelial polyps were found in only nine cases.
Figure 2 Magnetic resonance urethrography revealing soft tissue filling in the UPJ and hydronephrosis; the renal cyst is clearly displayed.
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Intraoperative findings of FEPs (arrows).
UPJ obstruction is a very common cause of pediatric hydronephrosis and UFP can be an extremely rare etiology of that [5,6]. However, UFP must be recognized as an important etiology for hydronephrosis in children. The clinical presentation of UPJO caused by UFP is the same as those by other causes of UPJO, with intermittent lumbar pain or flank pain and hematuria being the most common [7e11]. Symptoms can be present for several years before the diagnosis, while other patients with UFP may be asymptomatic and may not be diagnosed throughout of their lives [12]. Ureteral fibroepithelial polyps can occur at any age e from newborns to adults older than 70 years of age [13,14]. The most common age is 6e12 years, and the majority of the children reported in the literature were school age, which is similar to the present series with male predominance [8e11]. Ureteral fibroepithelial polyps occur more frequently on the left side and are often located in the UPJ and upper ureter, which is consistent with the present series. Pre-operative diagnosis of UFP can be difficult to make. The most effective way of currently diagnosing it is by imaging examination. Ultrasound always shows dilatation of the renal pelvis and part of the ureter, but is considered to be not that accurate. In the present series, US confirmed only one boy. Wang et al. reported their experience of utilizing US for the diagnosis of 35 pediatric UFP. They
Figure 4 Histological examination shows that the polyp is composed of a fibrous core covered by normal urothelium with inflammatory cell infiltration.
Please cite this article in press as: Dai LN, et al., Retroperitoneal laparoscopy management for ureteral fibroepithelial polyps causing hydronephrosis in children: A report of five cases, Journal of Pediatric Urology (2015), http://dx.doi.org/10.1016/j.jpurol.2015.02.019
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1.e4 thought that UFP could be visualized with US, and their US accuracy rate reached 62.2%, which was higher than IVU (24.3%) [11]. However, some studies have found that IVU is a more sensitive means of diagnosing UFP over US or a nuclear medicine renal excretory study [5]. Radojicic et al. advised that retrograde pyelography or ureteroscopy might be required to differentiate UFP from other causes of UPJ or ureteric obstruction [16]. All boys in the present series underwent IVU and showed typical filling defects after IVU confirmed fibroepithelial polyps. But in some special cases that are associated with other diseases of the relevant systems, CT and MRU might be supplemental tests. Surgical treatment for symptomatic UFP is recommended. Laparoscopic surgery is initially considered because laparoscopic pyeloplasty has been performed for UPJO in children. The UFP have been found to have an aquatic-plant-like appearance, growing upwards along the ureter, but the pedicles were actually located in the upper ureter. UPJ obstruction, displayed by radiographic examinations, has been due to the floating ends of polyps e the longest of which was almost 35 mm in length. Pre-operative diagnosis of UFP is difficult to make, and the aquatic-plantlike polyps make it even harder to decide where to cut. In the present series, when UPJ was opened, the end of polyps could be seen, the pedicles of which were located in the distal ureter. Therefore, it was thought that if UFP were considered before surgery, the UPJ should not be transversely cut; otherwise, the ureter might be too short to anastomose after the segment of ureteral area containing the pedicles has been excised. If the ureter is opened longitudinally, and the distance from the pedicles to the UPJ is shorter than 2 cm, pyeloplasty might be feasible. If the distance exceeds 2 cm, it is difficult to perform anastomosis after removal of too much ureter. Therefore, the UPJ site containing the polyp must be removed and the edge of the renal pelvis and the spatulate ureter anastomosed. In these five cases, the roots of the polyps were observed by retroperitoneal laparoscopy and they were completely removed during a laparoscopic procedure. Laparoscopic surgery could be one of the options for minimally invasive treatment for children and to achieve complete resection of the polyp at the UPJ. Endoscopic management has been reported in previous literature. If the polyps are ureterscopically removed, a close follow-up is important to avoid possible recurrence. In 1998, there was a 16-year-old boy diagnosed with UFP recurrence who had ever been treated with endoscopy and holmium laser ablation. This case confirmed that endoscopic management might cause some possible recurrence. When retroperitoneoscopy was not carried out in the present institution (before 2003), the recurrence of a single polyp at the same location was found at 6-month follow-up and was ultimately resolved by open surgery rather than by endoscopy and holmium laser ablation. The etiology of UFP remains unknown and much speculation has suggested that it may be a congenital developmental defect or as a result of chronic irritation, calculi, infectious inflammation, allergic factors, obstruction, trauma and hormonal disturbances [4,12,15,16]. Ureteral fibroepithelial polyps often have a fibrovascular core covered with normal transitional epithelial cells or present only with polyps or inflammatory cell infiltration. The UFP in the present series were
L.N. Dai et al. composed of a fibrous core covered by normal urothelium with inflammatory cell infiltration. Macroscopically, they resembled an aquatic plant.
Conclusion The results of this single-center retrospective series suggest that UFP should be recognized as an important etiology of hydronephrosis in children. Although it is difficult to make the diagnosis before surgery, US and radiological examination, especially IVU, may assist. Therefore, schoolaged children with a history of flank pain, hematuria, or both, hydronephrosis with soft-tissue in the UPJ or proximal ureter, must be highly suspected as having UFP preoperatively. Appropriate consideration of UFP in the differential diagnosis of a urothelial mass is important in surgical management. Retroperitoneoscopy can be one of the options of minimally invasive treatment for children and can achieve complete resection of the UFP. The two key points that must be remembered are: confirm the location of UFP by investigation and do not resect the ureter too short.
Conflict of interest None declared.
Funding None declared.
Ethical statement Informed consent was obtained from all subjects and a license from the ethical committee was also issued.
Acknowledgement We would like to thank our colleagues from the Department of Pediatric Surgery, the 2nd Affiliated Hospital & Yuying Children’s Hospital of Wenzhou Medical University, for their assistance with data collection.
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