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Principles of Minimally Invasive Treatment of Pyeloureteral Duplication in Children

Sebastian Ionescu, Bogdan Andrei, Mihai Mocanu, Elena Licsandru, Daniela Pavel

Department of Pediatric Surgery, Emergency Clinical Hospital for Children “Marie S. Curie”, Bucharest, Romania



Sebastian Ionescu

Department of Pediatric Surgery

Emergency Clinical Hospital for Children “Marie S. Curie”

20 Bd. Constantin Brancoveanu, Sector 4, 041451 Bucharest, Romania

Tel/fax: 021/4601040

E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.



Aims: The most common complication in complete or partial pyeloureteral duplication is damage of the upper renal pole due to vesicoureteral reflux or ureterocele, condition that requires partial nephrectomy or ureteronephrectomy. The purpose of this study is to present and analyze the treatment results using the minimal invasive approach in complications of pyeloureteral duplication in children.

Materials and methods: We present 28 cases of upper pole nephrectomy in children with complete or partial pyeloureteral duplication. In all cases there was a non-functional renal upper pole due to the presence of vesicoureteral reflux in 20 cases and ureterocele in 8 cases. The laparoscopic approach was transperitoneal (in 26 cases) or retroperitoneal (in 2 cases). The mean age of the children was 6 (range 2-12). Preoperative evaluation included renal ultrasound, voiding cystourethrogram, intravenous urography, renal scintigraphy and blood analysis. We analyzed data concerning the operative time, the use of analgesics and antibiotics, the time to resume oral feeding, hospital stay and postoperative renal function.

Results: The mean operative time was 120 minutes but longer for the retroperitoneal approach. There were 2 types of complications: one intraoperative hemorrhage which required conversion and one postoperative urinoma treated with local drainage. Pain medication was required only in the first 2 days after surgery. The mean postoperative hospital stay was 4 days. The postoperative renal function of the lower pole, evaluated by blood samples (blood urea nitrogen, plasma creatinine) and scintigraphy was normal in all cases during 1 year postoperative follow-up.

Conclusion: Laparoscopic transperitoneal or retroperitoneal partial ureteronephrectomy is a safe and feasible procedure in children. We consider that laparoscopy offers a better visualization of the vessels to be ligated and the dissection plans. Using minimal access surgery, we had shorter postoperative recovery, good aesthetic postoperative scars and shorter hospital stay. For the reasons mentioned above, this technique is first choice over open partial nephrectomy.

Keywords: pyeloureteral duplication, minimally invasive, children, nephrectomy



Nephrectomy, one of the first laparoscopic interventions performed the children, was reported for the first time in 1991 by Clayman [1] using a transperitoneal approach. Later on, in 1993 Jordan and Winslow [2] reported the first laparoscopic upper pole partial nephrectomy with ureterectomy. Soon after, laparoscopy became the first choice in the treatment of many renal duplex system complications in children [3].

The most common complication in complete or partial pyeloureteral duplication is damage of the upper renal pole due to vesicoureteral reflux or ureterocele, condition that requires partial nephrectomy / ureteronephrectomy [4].

The aim of this study is to analyze and report the results of minimal invasive treatment in 28 cases with non-functional renal upper pole, complications of complete pyeloureteral duplication, focusing on surgical indication, technical variants and functional postoperative results.

Materials and Methods

This retrospective, analytic study was performed in the Department of Pediatric Surgery of the Emergency Clinical Hospital for Children “Marie. S. Curie” between 2008-2014.

Preoperative evaluation was done using laboratory analysis (urea, creatinine, complete blood count, urinalysis and urine culture), renal ultrasound, voiding cystography and renal scintigraphy with DTPA (Fig. 1, 2, 3). Intravenous urography, computed tomography urography or magnetic resonance urography was performed in 7 patients for more accurate anatomical details. Indication for surgery was the presence of a nonfunctional upper pole, often with complete duplication of the ureter, dilated renal moiety and thinned renal parenchyma (1 mm-2 mm).

Figure 1. Renal scintigraphy with DTPA – non-functional left renal upper pole in complete pyeloureteral duplication with stenosis of the ureter

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Out of the 28 operated cases using the minimal invasive aproach, 26 were approached transperitoneal and 2 retroperitoneal. The upper moiety dilatation was caused by the presence of ureterocele in 8 cases and vesicoureteral reflux in 20 cases. Patient’s age ranged from 2-12 years, with an average of 6 years.

Figure 2. Voiding cystourethrography in a case with left pyeloureteral complete duplication with ureterocele of the upper moiety (A) and grade III vesicoureteral reflux in the lower moiety (B)

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Figure 3. Voiding cystourethrography – bilateral completepyeloureteral duplication with bilateral vesicoureteral reflux

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The operative technique for transperitoneal approach

The patient is positioned in lateral decubitus, with a side raised at about 45°. Pneumoperitoneum (10-12 mmHg) is obtained at a flow rate of 1- 2L/min through the umbilical trocar inserted by open access. The other three 5 mm trocars are placed in the epigastrium, right inferior abdominal flank or left inferior abdominal flank - on the lesion side and in the hypochondrium [5]. After incision of the peritoneum along the Toldt line, the colon is mobilized medially and Gerota fascia is opened. Dissection of the upper moiety together with the ureter is performed so as to avoid damage of the lower moiety and the ureter, followed by uncrossing the lower moiety vessels [6]. Next, we identify the upper moiety pedicle and transect it after clipping (in 6 cases) or using Ligasure (in 22 cases). The upper pole renal parenchyma is transected with electrocautery (6 cases) or with Ligasure (22 cases). We don’t perform the suture of the renal capsule above the sectioned upper kidney pole. The ureter of the upper moiety is sectioned close to the bladder in cases of vesicoureteral reflux, being ligated in advance or unligated in cases of ureteroceles. A drainage tube, in the renal fossa, was placed in all cases and was maintained between 1 and 3 days, depending on the drainage flow (Fig. 4).

In this study, we analyzed the operative time, intraoperative hemostasis problems, the need for analgesics and antibiotics, time to resume enteral nutrition, length of hospital stay and longterm functional evaluation of the remaining kidney.

Figure 4. Intraoperative aspects in complete pyeloureteral duplication with vesicoureteral reflux in the upper moiety during upper pole ureteronephrectomy by transperitoneal approach. (A) Upper ureter dissection from the vessels of the lower moiety. (B) Uncrossing the ureter from the lower moiety vessels. (C) The renal

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From the total of 28 cases, the procedure was completed laparoscopically in 27 cases because one patient required conversion due to bleeding from the upper moiety hilum which could not be controlled with minimally invasive access. In the rest of the cases, the intraoperative blood loss was minimal.

Operating time ranged from 90-150 minutes with an average time of 120 minutes. One patient presented fever (38 °C) in the 5th postoperatively day, and ultrasonography revealed an urinoma with 7 cm diameter which required percutaneous drainage guided by ultrasound with a complete resolution after 4 days. All children received fluids orally in the night after surgery and were fed per mouth in the first postoperative day. Normal gastro-intestinal transit resumed 1-2 days after surgery.

The patients received intravenous antibiotics for 48 hours after surgery. In some cases, analgesics were administered orally 48 hours after surgery. The length of hospital stay was between 2 and 9 days, with an average of 4 days. Mean follow-up was 2 years, between 1 and 5 years. Urea and creatinine serum were in a normal range during follow up (1 month, 6 months, 12 months postoperatively), and the blood pressure was in normal range in all cases. In the cases associated with ureterocele, at the follow-up ultrasound, it was shown to be collapsed 1-6 months after surgery.

An ultrasound examination was performed after one month, 6 months, 12 months postoperatively, and then annually. Renal scintigraphy was performed after 6 months and it showed in all cases the maintenance or improvement of renal function, without damage of the remaining kidney. Aesthetic results were satisfactory for patients and family with no cases of abdominal wall complications or bowel obstruction.


From early 90s, starting with the development and miniaturization of the laparoscopic instruments but also due to better understanding of the hemodynamic changes produced by pneumoperitoneum in children, indications for minimally invasive pediatric surgery have expanded continuously. Among these, the polar nephrectomy for renal congenital pathology emerged as a standard technique [7].

Heminephrectomy practiced using the open approach requires a large incision and mobilization of the entire kidney which can lead to damage of the remaining kidney [8].

During the minimal invasive technique, the kidney is approached "in situ" with a minimum mobilization, with better further results on the remaining kidney and obviously is virtually free of parietal complications. Good visualization of the vascular pedicle of the upper moiety allows sectioning of the demarcation between the two moieties with resection of the dysplastic upper renal pole and no damage of the residual kidney. Some authors recommend the use of ultrasonic dissector for parenchymal resection, but electrocautery may be used if vascular demarcation is clear. Ligasure is also a good option for vessels and parenchyma [9].

There is controversy over the transperitoneal or retroperitoneal approach. Proponents for the retroperitoneal approach believe that this provides good exposure of the posterior part of the kidney, avoiding the pedicle of the lower renal pole which can be left in place [10]. Retroperitoneal approach can be posterior or lateral. Posterior approach is preferred when ureterectomy is not necessary, the lateral approach providing better access for complete resection of the ureter [11]. The main disadvantages of the retroperitoneal approach are smaller workspace and a higher incidence of peritoneum perforation which prevents creation of an adequate retropneumoperitoneum and represents a cause of conversion [12].

On the other hand, the transperitoneal approach avoids these difficulties, providing a large working space, especially in young children (under 5 years), improving the surgeon’s comfort. We have obtained greater freedom of movement of the laparoscopic instruments, positioning the child on the edge of the operating table, on the surgeon and the cameraman side [13]. We prefer the transperitoneal approach, especially in young children, because the risk of intraoperative bowel injury is minimal and postoperative bowel obstruction is rare. In our series there were no complications related to the type of approach used. The patient who required conversion due to bleeding of the upper moiety vessels represented 5% of the total cases which is similar to results found in the literature. We also had a postoperative complication in a patient who underwent percutaneous drainage for urinoma in the upper renal pole; its frequency was also similar to data reported by other similar series [12].

The evaluation of postoperative pain in children is subjective, being hard to quantify, but the reduced need for analgesics was obvious. Antibiotic therapy was also administered only for 48 hours.

Most studies don’t show a statistically significant difference in the operative time, and when it is reported, depends on the learning curve [8]. We recorded an average duration of 2 hours in our patients and it is comparable with the average duration in the classic interventions. Postoperative follow-up (blood analysis, blood pressure, ultrasound and renal scintigraphy), showed no deterioration in any of these parameters, and about half of the patients showed an improvement in the remaining parenchyma at the renal scintigraphy at 6 months after surgery. This evolution is more probably due to reexpansion of the renal parenchyma, previously compressed by the dilated upper renal pole, than due to improving tubular function [14, 15].


Laparoscopic hemi-nephrectomy performed either trans or retroperitoneal is the first choice of treatment in children. Magnification provided by the telescope allows good highlighting of the upper renal pole structures, making the dissection safe and efficient. This approach allows distal section of the ureter without additional incisions and minimizes trauma to the vessels and the remaining lower renal parenchyma, reducing the possibility of long-term deterioration of the renal function. We prefer the transperitoneal approach, especially in young children because it offers a better working space, without complications such as intestinal lesions or postoperative bowel obstruction.

With this approach, postoperative recovery was shorter, there were no abdominal wall complications and the cosmetic results were satisfactory. For these reasons, we consider the laparoscopic approach as the first choice of treatment in children with indication for upper pole nephrectomy, because they can benefit from all the advantages of the minimal invasive technique.




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