# Vesicoureteral Reflux and Duplex Systems

Authors: John C. Thomas
Journal: Advances in Urology
 (2008)

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## Abstract

Vesicoureteral reflux (VUR) is the most common anomaly associated with duplex systems.  In addition to an uncomplicated duplex system, reflux can also be secondary in the presence of an ectopic ureterocele with duplex systems.  Controversy exists in regard to the initial and most definitive management of these anomalies when they coexist.  This paper will highlight what is currently known about duplex systems and VUR, and will attempt to provide evidence supporting the various surgical approaches to an ectopic ureterocele and duplex system and the implications of concomitant VUR.


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## Body

## 1. Introduction

Less than 1% of the
general population has a duplex kidney [1]. Females are affected more commonly than males and this anomaly is bilateral
in 17–33% of cases [2]. VUR is the most common associated anomaly
found in duplex kidneys and is present in 70% of these patients who present
with a urinary tract infection [3, 4]. VUR almost always occurs into the lower-pole moiety due to its lateral
displacement within the bladder. If VUR
is seen in the upper-pole moiety, one must suspect a laterally displaced
incomplete duplication or an ectopic orifice located within the bladder neck or
urethra. This paper will review the
natural history of VUR associated with uncomplicated duplex systems as well as
the controversies that arise in managing reflux found in conjunction with ectopic
ureteroceles.


## 2. Discussion

### 2.1. VUR and Duplex Systems

There are certain
factors that contribute to reflux resolution in single-system (SS) ureters,
including patient age, grade of reflux, postnatal presentation, and the
presence or absence of associated voiding dysfunction [4]. The natural history of VUR in association
with duplex systems (DSs) is not completely clear. Despite several studies addressing this
issue, all were limited in some way by their noncontrolled retrospective
nature, patient selection or surgeon bias, and limited long-term follow-up [4]. Lee et al. followed 1/3 of their patients
with VUR and DS nonoperatively, and concluded that resolution rates of low-grade
(I-II/V) reflux were comparable to those seen in SS [5]. Patients with high-grade reflux were excluded
from this study. A similar conclusion
was noted in another study in which all grades of reflux were included. Spontaneous resolution occurred in over half
of patients with grades I–III/V VUR and support
consideration for initial conservative management with prophylactic antibiotics
[6]. Over a two-year period of
observation, Husmann et al. found that reflux resolved in 10% of patients with
DS and grade II/V VUR as compared to 35% of a matched group of patients with SS;
however, there were no differences in the incidence of breakthrough infections,
additional renal scarring, or worsening reflux [7]. It seems clear that most patients with DS and
low grades (<III/V) can be initially managed conservatively; however, VUR
will likely take longer to resolve as compared to SS VUR. Clinical information concerning high-grade
VUR (IV-V) and DS is lacking, although one study documented no resolution at
mean follow-up of 42 months as well as an increased incidence of infectious
complications, especially in young females [4].Data from the available
literature suggests that the majority of patients with DS and low-grade VUR can
be initially managed with antibiotics and careful observation. Parents  should be counseled that it may take
longer for the reflux to resolve and young females with high-grade VUR may be
at increased risk for infections. Despite these findings, the absolute indication for surgery in
individuals with low-grade VUR is not different from those with SS and similar VUR,
and surgical correction is successful in the majority of cases [4]. In fact, one series reported a 98% success
rate for common sheath reimplantation of uncomplicated duplex systems, and
concluded that the presence of a duplication anomaly does not adversely affect
surgical outcome. Adequate tunnel width
and long intravesical tunnels were noted to be the most important technical
aspects [8]. It is important to
remember, however, that complicated duplex systems associated with the need for
ureteroureterostomy, ureteral tapering or tailoring, or ureteropyelostomy may
carry higher complication rates than uncomplicated common sheath
reimplantation.


### 2.2. Ectopic Ureteroceles and Vesicoureteral Reflux

Duplex systems are an
uncommon diagnosis causing prenatal hydronephrosis; however, when confirmed,
ureteroceles are one of the most common associated findings [9, 10]. Ectopic ureteroceles can cause upper-pole
hydronephrosis and obstruction, which leads to ipsilateral lower-pole reflux in
50% of cases [11]. Contralateral reflux
is seen in 25% of cases and reflux into the ureterocele occurs 10% of the time [12].The initial and subsequent management of ureteroceles has been
controversial and depends on several factors, including presenting symptoms, ectopic
versus orthotopic position, presence or absence of reflux, and function of the
associated upper-pole moiety [11]. As
the focus of this article is reflux and duplex systems, the discussion below
will be limited to the management of ectopic ureteroceles in patients who
present with concomitant reflux and a nonfunctioning or functioning upper-pole
moiety.  Management options include
endoscopic puncture and decompression, a simplified upper-tract approach, namely,
heminephrectomy, or complete repair including upper-pole surgery, ureterocele
excision, and lower-tract reconstruction in a single setting.In the above proposed setting, the clear indication for endoscopic
decompression of an ectopic ureterocele is in a child who presents with sepsis or
bladder outlet obstruction. However, in the
setting of sepsis, one must open the ureterocele completely, as puncturing may
not result in adequate drainage. This
procedure almost invariably results in prompt improvement in patient symptoms,
but the parents should be counseled that their child will require definitive reconstruction
at a later date, as reflux into the upper-pole moiety is the rule, not the
exception. In contrast, endoscopic
puncture of an ectopic ureterocele in the nonemergent setting may also commit
the patient to future reconstruction. In
one series describing endoscopic puncture for ectopic ureteroceles, Jayanthi et
al. reported postoperative reflux into the upper-pole moiety in 50% of cases [13]. Overall, 70% of their patients underwent open
surgery with the vast majority at the level of the bladder [13]. Some have argued that initial endoscopic
decompression may facilitate subsequent lower-tract surgery by reducing the
size of the upper-pole ureter [14].Upper-pole heminephrectomy can result in excellent decompression of the
ureterocele and should be the procedure of choice if there is no ipsilateral
lower pole or contralateral reflux [15]. Removing a functional upper pole has been advocated by some as this
moiety only provides approximately 15% of total renal function at best [16]. Alternatively, one can salvage the upper pole
with a ureteroureterostomy or ureteropyelostomy and subtotal ureterectomy. Success of the upper-tract approach alone
without the need for subsequent bladder surgery is directly related to the
presence or absence of ipsilateral lower pole or contralateral reflux. Husmann et al. reported a definitive cure in
only 16% of patients in this setting if endoscopic decompression or an upper-tract
approach was used alone. In fact, the
need for additional surgery was related to the number of renal moieties with
reflux at presentation, reporting a 96% reoperative rate with unilateral high-grade
reflux or reflux seen in more than one renal moiety [16].In conclusion, ectopic ureteroceles that reflux or are associated with
reflux into other moieties are likely best served with ureterocele excision or
marsupialization, bladder floor reconstruction, and ureteral reimplant. Another option would be a ureteroureterostomy
with a lower-pole extravesical reimplant. In those patients who present with sepsis or bladder outlet obstruction,
endoscopic decompression is highly successful but will likely commit the
patient to further surgery. Upper-pole
heminephrectomy is best applied to those patients with nonfunctioning upper
poles and no associated reflux. In this
setting, this approach is highly successful and has the advantage of avoiding
bladder surgery, limiting risks to the lower pole, and eliminating the
potential unknown risks of preserving a dysplastic upper pole [15]. Arguably, upper-pole heminephrectomy can be
performed open or laparoscopically.


## 2.1. VUR and Duplex Systems

There are certain
factors that contribute to reflux resolution in single-system (SS) ureters,
including patient age, grade of reflux, postnatal presentation, and the
presence or absence of associated voiding dysfunction [4]. The natural history of VUR in association
with duplex systems (DSs) is not completely clear. Despite several studies addressing this
issue, all were limited in some way by their noncontrolled retrospective
nature, patient selection or surgeon bias, and limited long-term follow-up [4]. Lee et al. followed 1/3 of their patients
with VUR and DS nonoperatively, and concluded that resolution rates of low-grade
(I-II/V) reflux were comparable to those seen in SS [5]. Patients with high-grade reflux were excluded
from this study. A similar conclusion
was noted in another study in which all grades of reflux were included. Spontaneous resolution occurred in over half
of patients with grades I–III/V VUR and support
consideration for initial conservative management with prophylactic antibiotics
[6]. Over a two-year period of
observation, Husmann et al. found that reflux resolved in 10% of patients with
DS and grade II/V VUR as compared to 35% of a matched group of patients with SS;
however, there were no differences in the incidence of breakthrough infections,
additional renal scarring, or worsening reflux [7]. It seems clear that most patients with DS and
low grades (<III/V) can be initially managed conservatively; however, VUR
will likely take longer to resolve as compared to SS VUR. Clinical information concerning high-grade
VUR (IV-V) and DS is lacking, although one study documented no resolution at
mean follow-up of 42 months as well as an increased incidence of infectious
complications, especially in young females [4].Data from the available
literature suggests that the majority of patients with DS and low-grade VUR can
be initially managed with antibiotics and careful observation. Parents  should be counseled that it may take
longer for the reflux to resolve and young females with high-grade VUR may be
at increased risk for infections. Despite these findings, the absolute indication for surgery in
individuals with low-grade VUR is not different from those with SS and similar VUR,
and surgical correction is successful in the majority of cases [4]. In fact, one series reported a 98% success
rate for common sheath reimplantation of uncomplicated duplex systems, and
concluded that the presence of a duplication anomaly does not adversely affect
surgical outcome. Adequate tunnel width
and long intravesical tunnels were noted to be the most important technical
aspects [8]. It is important to
remember, however, that complicated duplex systems associated with the need for
ureteroureterostomy, ureteral tapering or tailoring, or ureteropyelostomy may
carry higher complication rates than uncomplicated common sheath
reimplantation.


## 2.2. Ectopic Ureteroceles and Vesicoureteral Reflux

Duplex systems are an
uncommon diagnosis causing prenatal hydronephrosis; however, when confirmed,
ureteroceles are one of the most common associated findings [9, 10]. Ectopic ureteroceles can cause upper-pole
hydronephrosis and obstruction, which leads to ipsilateral lower-pole reflux in
50% of cases [11]. Contralateral reflux
is seen in 25% of cases and reflux into the ureterocele occurs 10% of the time [12].The initial and subsequent management of ureteroceles has been
controversial and depends on several factors, including presenting symptoms, ectopic
versus orthotopic position, presence or absence of reflux, and function of the
associated upper-pole moiety [11]. As
the focus of this article is reflux and duplex systems, the discussion below
will be limited to the management of ectopic ureteroceles in patients who
present with concomitant reflux and a nonfunctioning or functioning upper-pole
moiety.  Management options include
endoscopic puncture and decompression, a simplified upper-tract approach, namely,
heminephrectomy, or complete repair including upper-pole surgery, ureterocele
excision, and lower-tract reconstruction in a single setting.In the above proposed setting, the clear indication for endoscopic
decompression of an ectopic ureterocele is in a child who presents with sepsis or
bladder outlet obstruction. However, in the
setting of sepsis, one must open the ureterocele completely, as puncturing may
not result in adequate drainage. This
procedure almost invariably results in prompt improvement in patient symptoms,
but the parents should be counseled that their child will require definitive reconstruction
at a later date, as reflux into the upper-pole moiety is the rule, not the
exception. In contrast, endoscopic
puncture of an ectopic ureterocele in the nonemergent setting may also commit
the patient to future reconstruction. In
one series describing endoscopic puncture for ectopic ureteroceles, Jayanthi et
al. reported postoperative reflux into the upper-pole moiety in 50% of cases [13]. Overall, 70% of their patients underwent open
surgery with the vast majority at the level of the bladder [13]. Some have argued that initial endoscopic
decompression may facilitate subsequent lower-tract surgery by reducing the
size of the upper-pole ureter [14].Upper-pole heminephrectomy can result in excellent decompression of the
ureterocele and should be the procedure of choice if there is no ipsilateral
lower pole or contralateral reflux [15]. Removing a functional upper pole has been advocated by some as this
moiety only provides approximately 15% of total renal function at best [16]. Alternatively, one can salvage the upper pole
with a ureteroureterostomy or ureteropyelostomy and subtotal ureterectomy. Success of the upper-tract approach alone
without the need for subsequent bladder surgery is directly related to the
presence or absence of ipsilateral lower pole or contralateral reflux. Husmann et al. reported a definitive cure in
only 16% of patients in this setting if endoscopic decompression or an upper-tract
approach was used alone. In fact, the
need for additional surgery was related to the number of renal moieties with
reflux at presentation, reporting a 96% reoperative rate with unilateral high-grade
reflux or reflux seen in more than one renal moiety [16].In conclusion, ectopic ureteroceles that reflux or are associated with
reflux into other moieties are likely best served with ureterocele excision or
marsupialization, bladder floor reconstruction, and ureteral reimplant. Another option would be a ureteroureterostomy
with a lower-pole extravesical reimplant. In those patients who present with sepsis or bladder outlet obstruction,
endoscopic decompression is highly successful but will likely commit the
patient to further surgery. Upper-pole
heminephrectomy is best applied to those patients with nonfunctioning upper
poles and no associated reflux. In this
setting, this approach is highly successful and has the advantage of avoiding
bladder surgery, limiting risks to the lower pole, and eliminating the
potential unknown risks of preserving a dysplastic upper pole [15]. Arguably, upper-pole heminephrectomy can be
performed open or laparoscopically.


## 3. Conclusions

Reflux found in
association with a duplex system may take longer to resolve than single-system
reflux. Parents should be counseled
accordingly. Surgery to correct VUR in
duplex systems is highly successful. Ectopic
ureteroceles can present an interesting and difficult surgical challenge and
can be ultimately managed with multiple surgical approaches following initial
conservative therapy. Endoscopic
decompression seems best reserved for the septic patient or one who presents
with bladder outlet obstruction. It
provides excellent relief of obstruction and can preserve upper-pole renal
function. Ultimately, these patients are
currently managed by either an upper- or lower-tract approach. The most important factor in deciding which
approach to take is the presence or absence of VUR.



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*Source: 651891-2008-07-17.xml*