A ureterocele is a cystic out-pouching of the distal ureter into the urinary bladder.[1] It is one of the more challenging urologic anomalies facing pediatric and adult urologists. Ureteroceles may pose a diagnostic and therapeutic dilemma, with perplexing clinical symptoms resulting from a spectrum of abnormal embryogenesis associated with anomalous development of the intravesical ureter, the kidney, or the collecting system.
Ureteroceles may be categorized on the basis of their relationship with the renal unit or on distal ureteral configuration and location. The following are the different types of ureteroceles classified by their association with the renal unit:
Single-system ureteroceles are those associated with a single kidney, collecting system, and ureter.
Duplex-system ureteroceles are associated with kidneys that have completely duplicated ureters.
Orthotopic (intravesical) ureterocele is a term used for a ureterocele contained within the bladder. An orthotopic ureterocele may prolapse into and beyond the bladder neck, but the origin of the walls of an orthotopic ureterocele are contained within the bladder. The orthotopic ureterocele usually arises from a single renal unit with one collecting system and is more commonly diagnosed in adults.
Ectopic (extravesical) ureterocele refers to ureteroceles with tissue that originates at the bladder neck or beyond, into the urethra. They typically arise from the upper pole moiety of a duplicated collecting system and are more common in the pediatric population.
Keep in mind that not all single-system ureteroceles assume an orthotopic position and that not all duplex collecting system ureteroceles are positioned in an ectopic location.
Another method of classifying ureterocele is based on location and configuration. Stephens proposed a classification system based on the features of the affected ureteral orifice, as follows[2] :
Stenotic ureteroceles are located inside the bladder with an obstructing orifice.
Sphincteric ureteroceles lie distal to the internal sphincter. The ureterocele orifice may be normal or patulous, but the distal ureter leading to it becomes obstructed by the activity of the internal sphincter.
Sphincterostenotic ureteroceles have characteristics of both stenotic and sphincteric ureteroceles.
Cecoureteroceles are elongated beyond the ureterocele orifice by tunneling under the trigone and the urethra.
At present, this classification is used infrequently. The characterization based on the location of the orifice (intravesical vs ectopic) is more commonly used because it has therapeutic implications, especially with respect to the likelihood of the presence of vesicoureteral reflux following transurethral puncture of the ureterocele.
Ureteroceles may be asymptomatic or may produce a wide range of clinical signs and symptoms, from recurrent cystitis to bladder outlet obstruction to kidney failure. Because of the obstructive nature of ureteroceles, the activity of the affected renal unit varies from a normal, well-functioning kidney to a nonfunctioning, dysplastic renal segment or kidney. However, with proper diagnosis and treatment, the outcome remains excellent.
Management of ureterocele remains both challenging and controversial, with its wide clinical spectrum making development of a standardized approach difficult. Robotic-assisted ureteral reimplantation and heminephrectomy are gaining popularity and will continue to evolve.[3] Open ureteral reimplantation, ureteropyelostomy and heminephrectomy currently remain the criterion standard for surgical management of symptomatic ureteroceles that are not successfully managed endoscopically.
Although different surgical philosophies exist in managing adult and pediatric ureteroceles, the following principles may apply:
Endoscopic puncture of ureteroceles should be used as a primary treatment modality in any patient with urosepsis or concurrent medical conditions that pose significant anesthesia-related risk.
Upper pole heminephrectomy with partial ureterectomy is reasonable in the setting of a nonfunctioning upper pole renal moiety without associated vesicoureteral reflux.
Ureterocelectomy and bladder reconstruction are acceptable in the setting of a ureterocele associated with significant vesicoureteral reflux in either kidney.
For information on pediatric ureterocele, see Ureteral Duplication, Ureteral Ectopia, and Ureterocele.
Ureters are paired muscular tubes running from the renal pelvis to the bladder. They travel through retroperitoneal connective tissue in a serpentine fashion. In the adult, the ureter is approximately 30 cm long but varies with body habitus. The ureter is a urinary conduit composed of inner longitudinal smooth muscle fibers and an outer layer of circular and oblique smooth muscle cells. The inner and longitudinal muscle layers are enveloped by a thin layer of adventitia that contains an extensive plexus of blood vessels and lymphatics that course parallel to the ureter. In a normal state, urine is actively propelled from the renal pelvis down to the bladder via contractions of the ureter.
The ureter receives its blood supply from numerous sources. In the segment of the ureter from the renal pelvis to the common iliac artery, which is referred to as the abdominal ureter, the blood supply includes the renal artery, the aorta, the gonadal artery, and the common iliac artery. The blood supply of the abdominal ureter enters medial to the ureter. In the segment of the ureter from the common iliac artery to the urinary bladder, which is termed the pelvic ureter, the blood supply includes the internal iliac, vesical, uterine, middle rectal, and vaginal arteries. The blood supply of the pelvic ureter enters laterally. The gonadal vessels run parallel to the ureter in the retroperitoneum until it courses obliquely from medial to lateral as it enters the pelvis.
The ureter is most narrow at the ureterovesical junction, followed by the ureteropelvic junction, and then at the crossing of the iliac vessels.
The ureterovesical junction may be divided into 3 sections, as follows:
Terminal portion (juxtavesical ureter)
Intramural portion
Submucosal portion (lying under the mucosa of the bladder)
It is important to make a distinction between orthotopic and ectopic ureteroceles, since therapeutic options and outcomes differ between these two clinical entities. The development of an ectopic ureterocele is best explained by reviewing the embryogenesis of the kidney and ureter.
Embryogenesis of the kidney and ureter
The ureter forms from the ureteric bud, which branches off the caudal portion of the Wolffian (mesonephric) duct during the first 4-6 weeks of gestation. The cranial portion of the ureteral bud joins with the metanephric blastema, a primitive analog of the kidney, and begins to induce nephron formation. The ureteral bud subsequently branches into the renal pelvis and the calyces and induces nephron formation.
Caudally, the mesonephric duct and the ureteral bud are incorporated into the anterior portion of the cloaca (urogenital sinus) as it forms the bladder trigone. At this point, perforation of the Chwalla membrane occurs, allowing the formation of a normal ureteral orifice. If the membrane does not completely perforate, a ureterocele results.
Importantly, alterations in the number of ureteral buds also result in ureteral anomalies. Before the mesonephric duct is absorbed into the urogenital sinus, it usually produces a single ureteral bud. Complete ureteral duplication occurs when the mesonephric duct produces a second ureteral bud that interacts with the metanephric blastema.
The lower ureteral bud, which is therefore closest to the urogenital sinus, becomes the lower pole ureter, and the bud farther away becomes the upper pole ureter. As the common excretory duct is absorbed into the expanding urogenital sinus, the lower pole ureteral orifice becomes located more cephalad and lateral; the upper pole orifice, which is incorporated later, if at all, will therefore be located more caudal and medial. This is known as the Meyer-Weigert law.
Because the lower pole ureteral bud is located more cephalad and lateral, its detrusor submucosal tunnel is shortened, which predisposes the lower pole ureter to reflux. In contrast, the upper pole ureteral bud is absorbed slowly, which results in a longer submucosal tunnel. The timing of incorporation of the ureter into the urogenital sinus as well as the perforation of the Chwalla membrane likely determine whether a ureterocele will be orthotopic or ectopic in location.
The precise embryologic etiology of the ureterocele remains unknown. Theorized causes include the following:
Obstruction of the ureteral orifice
Incomplete muscular development of the intramural ureter
Excessive dilatation of the intramural ureter during the development of the bladder and trigone
The most commonly accepted theory behind ureterocele formation is obstruction of the ureteral orifice during embryogenesis, with incomplete dissolution of the Chwalla membrane. This is a primitive, thin membrane that separates the ureteral bud from the developing urogenital sinus. Failure of this membrane to completely perforate during development of the ureteral orifice is thought to explain the occurrence of a ureterocele.
Ureteroceles occur in approximately 1 in every 4000 children and occur most commonly in whites.[4] Females are affected 4-7 times more often than males. A slight left-sided preponderance appears to exist, and approximately 10% of ureteroceles are bilateral. In the adult population, ureteroceles also occur more frequently in females. Orthotopic ureteroceles occur in 17-35% of cases, with an incidence of ectopic ureteroceles of approximately 80% in most pediatric series. Similarly, approximately 80% of ureteroceles are associated with the upper pole moiety of a duplex system. When ectopic ureteroceles are associated with duplicated collecting systems, the upper pole moiety may be dysplastic or poorly functioning. Single-system ectopic ureteroceles are uncommon and are most often found in males.
No single approach is appropriate for all patients with ureteroceles; therefore, each case must be tailored to the individual. An experienced surgeon must be armed with various surgical techniques that can be tailored to effectively treat different types of ureterocele malformations. When an appropriate operation is used to correct a specific abnormality, the outcomes remain excellent in both pediatric and adult patients.
A retrospective comparison of ureterocele treatment with laser puncture in 12 neonates and electrosurgery incision in 20 neonates found that both techniques were highly effective in relieving the obstruction. There were no significant differences regarding hospitalization, need for retreatment, and the occurrence of complications.[5]
A meta-analysis of outcomes of endoscopic treatment of ureteroceles found that rates of secondary operations were higher with ectopic and duplex-system ureteroceles than with intravesical and single-system ureteroceles. Postoperative vesicoureteral reflux (VUR) rates were also significantly higher in patients with ectopic or duplex-system ureteroceles.[6]
Currently, most pediatric ureteroceles are found during routine prenatal screening. Adult ureteroceles may also be found incidentally during imaging studies, often obtained for complaints of unrelated symptomatology. Ureteroceles frequently do not have clinical sequelae in the adult population. However, when problems arise, presenting clinical features of ureteroceles may include the following:
Urinary tract infection (UTI)
Urosepsis
Obstructive voiding symptoms
Urinary retention
Failure to thrive
Hematuria
Cyclic abdominal pain
Ureteral calculus
Pathologic ureteroceles most often affect the pediatric population. In young infants, failure to thrive or urinary tract infection may be the first sign of a symptomatic ureterocele.
Complications of ureteroceles in both pediatric and adult populations occur because of the obstructive nature of the ureterocele and its anatomic location. Because of the distal ureteral obstruction, the ipsilateral renal moiety is often hydronephrotic or dysplastic. The degree of hydronephrosis may wax and wane depending on the amount of urine produced by the renal moiety. Cyclical expansion and decompression of the renal pelvis manifests as intermittent abdominal pain in older children and adults.
In the setting of untreated UTIs and hydronephrosis, affected older children and adults may reveal signs and symptoms of pyonephrosis or frank urosepsis. The dilated ureterocele may cause urinary stasis and is a risk factor for ureteral stone formation within the saccular cavity. When distal ureteral stones develop, they cannot pass spontaneously because of the obstructing ureterocele orifice. Presence of stones within a ureterocele is exclusive to the adult population. A prolapsing ureterocele in a female patient may cause physical obstruction of the bladder neck. Anatomic obstruction of the bladder neck by the cystic ureterocele may incite obstructive voiding symptoms or may precipitate acute urinary retention in both pediatric and adult populations. Intravesical ureterocele has also been reported to cause bladder outlet obstruction in an adult male.[7]
During the physical examination, particular attention should be paid to the abdomen and the genitalia. This is true for both pediatric and adult populations. Symptomatic ureteroceles with hydronephrosis may manifest as abdominal tenderness to palpation. An abdominal mass due to a large hydronephrotic kidney may be appreciated in the upper abdominal quadrant in thin adults and young children. Flank tenderness often accompanies the abdominal findings. In infants, an abdominal mass due to hydronephrosis may be noted by transillumination in a dark room.
Rarely, on genital examination in a female with ureterocele, a prolapsing cystic mass may be seen emerging from the external meatus. This is a sign of a prolapsing ureterocele and occurs in less than 5% of symptomatic ureteroceles.[8] The differential diagnosis of a prolapsing mass in children should also include urethral prolapse, sarcoma botryoides, and urethral caruncle.
Prolapsing ureteroceles can also occur in boys, but they are much less common. Duplex systems are more likely to cause urethral obstruction in males, although they occasionally can occur with just a single system. A minority of ureteroceles are discovered incidentally during ureteral reimplantation for vesicoureteral reflux.
Urinalysis should be obtained in any child with an unexplained fever or suspicion of a urinary tract infection (UTI); the presence of pyuria, leukocyte esterase, and nitrites suggests a UTI. Urine culture is obtained to identify the offending pathogen and to assess for appropriate antibiotic susceptibility.
A complete blood cell count (CBC) is obtained to determine the degree of systemic infection that may be present, as well as to ascertain responsiveness to antibiotic therapy. Serum chemistries, especially blood urea nitrogen (BUN) and serum creatinine levels, are obtained to determine baseline information and to assess kidney function. Blood cultures are obtained in the setting of fever or urosepsis.
Fungal cultures are obtained in infants who have been on long-term antibiotic therapy or in immunocompromised patients with clinical evidence of UTI
Kidney and bladder ultrasonography is the first-line imaging study for evaluating the upper and lower urinary tract in children. Ultrasound findings dictate subsequent evaluations.[11]
Note the following:
A ureterocele is seen as a fluid-filled cystic intravesical mass.
Hydroureteronephrosis is noted as a dilatation of renal pelvis and the ureter.
Many ureteroceles are compressible with bladder filling and may be missed if the bladder is very full during imaging.
Ureteroceles associated with duplicated collecting systems typically will manifest upper pole hydroureteronephrosis on ultrasound.
Kidney ultrasonography also provides information on the thickness of renal cortex and echogenicity of renal parenchyma. The degree of echogenicity is indirectly proportional to the degree of renal dysplasia that is present.
Bladder ultrasonography documents the efficiency of bladder emptying by showing the amount of postvoid residual urine that is present.
Voiding cystourethrography
Voiding cystourethrography (VCUG) is essential to evaluate the lower urinary tract for a ureterocele, urethral diverticulum, posterior urethral valve (PUV), ectopic ureter, and vesicoureteral reflux. VCUG is obtained in children to confirm the diagnosis of ureterocele and assess for concomitant vesicoureteral reflux.
Ureterocele appears as a smooth, round filling defect along the base of the bladder. As the bladder fills, some ureteroceles will evert and appear as a bladder diverticulum.
Urethral diverticulum appears as an outpouching of the urethra. A urethral diverticulum may also represent an everting ureterocele.
VCUG can be used to document the efficiency of bladder emptying with assessment of the amount of postvoid residual urine that is present.
Posterior urethral valves (PUV) are included in the differential diagnoses of antenatal hydronephrosis. On VCUG, PUV are characterized by visualization of the valve leaflets, dilatation and elongation of the posterior urethra, and bladder neck hypertrophy.
Vesicoureteral reflux of the ipsilateral lower pole ureter approaches 50%, and 25% of the kidneys contralateral to the ureterocele will also have vesicoureteral reflux. In about 10% of cases, there will be reflux into the ureter drained by the ureterocele itself.
Diuretic nuclear renography (nuclear renal scan)
Nuclear renography may be performed to assess the relative function of the kidneys and upper renal pole when a duplicated system is suspected.
Nuclear renal scan using technetium 99m diethylenetriaminepentaacetic acid (DTPA) is an excellent study for establishing the differential renal function objectively and the efficiency of drainage of the dilated collecting system (washout times). DTPA is cleared almost exclusively by glomerular filtration. Its rate of clearance provides an excellent estimate of glomerular filtration rate (GFR).
Alternatively, technetium 99m mercaptoacetyltriglycine (MAG3) may be used. This radioisotope is rapidly cleared by tubular secretion and is not retained by the kidneys. MAG3 is an excellent replacement for DTPA (eg, diuretic renography) in the pediatric population.
Intravenous pyelography (IVP)
Historically, IVP has been the most useful study in diagnosis of ureterocele, although presently most ureteroceles are diagnosed by ultrasound. See the image below.
View Image
Intravenous urogram demonstrating left hydroureteronephrosis due to a ureterocele represented by the round filling defect located at the left base of ....
Intravenous pyelography is useful for delineating renal anatomy and providing a subjective estimation of relative kidney function. The following may be seen on IVP:
Hydronephrosis, revealing dilatation of collecting system
Hydronephrotic upper pole displacing the lower pole moiety laterally and inferiorly (ie, the "drooping lily")
Ureteral displacement by the hydroureter or hydronephrotic upper pole moiety
The cobra head sign
On IVP or computed tomography (CT) urogram, the presence of an intravesical ureterocele is indicated by the cobra head sign. In this sign, the dilated intravesical portion of the ureter forms the cobra's head, while the extravesical ureter forms the body of the cobra.[12]
Magnetic resonance imaging and computed tomography
MRI is an excellent anatomical study for evaluating rare cases with suspected dysplastic, nonfunctioning, ectopic renal moieties and ectopic ureteral insertion.
CT scanning of the abdomen and pelvis provides additional clues for diagnosing simple or ectopic ureterocele in adults when kidney ultrasonography findings are equivocal. CT can reveal the presence of a duplicated collecting system, hydronephrotic upper pole segment, and dysplastic upper pole moiety. It is an excellent tool to detect ureteral calculi; however, abnormal ureteral anatomy and ureteral dilatation are better imaged with MRI.
Cystoscopy, vaginoscopy, or retrograde pyelography are endoscopic procedures that allow direct inspection and examination of the lower urinary tract, as well as the female genitalia. Considerations are as follows:
For optimal demonstration of a ureterocele, one must examine the bladder when it is both full and empty
When radiologic study results in an adult arouse suspicion of a ureterocele, cystoscopy often confirms the imaging findings
If clinically indicated, the ureterocele may be treated with endoscopic incision or unroofing in the same setting
Typically, the walls of the ureterocele demonstrate loss of muscle and collagen. Incomplete muscular development of the distal ureter may be responsible for expansion of the ureterocele out of proportion to the normal ureter. However, the walls of stenotic ureteroceles appear to have greater muscle composition than other types of ureteroceles.
Observation alone is rarely a good option in symptomatic ureteroceles. Antibiotic prophylaxis is started in newborns with prenatally diagnosed ureterocele, which decreases the overall incidence of urinary tract infection (UTI). In the setting of urosepsis with ureterocele, the physician must rapidly initiate aggressive antibiotic therapy. Antibiotics should be instituted during the initial diagnostic evaluation and during surgical intervention for both pediatric and adult ureteroceles.
Indications for surgical treatment for both pediatric and adult ureteroceles depend on the site of the ureterocele, the clinical situation, associated renal anomalies, and the size of the ureterocele. Treatment of the ureterocele is indicated to relieve obstruction and to preserve kidney function. Indications for surgical intervention include the following:
Recurrent UTI
Urosepsis
Ureteral calculi
Intractable pain
Compromised kidney function
Urgent decompression with endoscopic incision, followed by a definitive bladder reconstruction, is often required in cases of urosepsis or severe azotemia. Indications for intervention in the pediatric and adult population are identical. A contraindication for correction of a ureterocele is a small, asymptomatic ureterocele not causing any dilatation of the collecting system.
Goals of treatment include the following:
Control of infection
Preservation of kidney function
Protection of ipsilateral and contralateral renal units
Maintenance of urinary continence
Elimination of obstruction and reflux
The surgical approach is selected based on the following:
Treatment of the ureterocele is individualized based on the following:
Patient age
Clinical situation
Type of ureterocele
Presence of vesicoureteral reflux
Kidney function
Surgeon preference
In the neonate or infant, transurethral puncture of the ureterocele or an upper tract approach (eg, heminephrectomy) are often the most feasible options, while excision of the ureterocele with bladder reconstruction or total reconstruction, including heminephrectomy, may be added to the therapeutic armamentarium in the older child (> 2 y). In the adult, transurethral unroofing of the ureterocele is a reasonable first-line approach, because the development of postoperative vesicoureteral reflux is less problematic than in the child.
For infants and children with an intravesical nonrefluxing ureterocele, endoscopic puncture is usually the first-line therapy because it is minimally invasive and has a high chance of providing definitive treatment.[13] For those with a nonrefluxing, poorly functioning upper pole associated with an ectopic ureterocele, an upper pole heminephrectomy is a reasonable first-line therapy. Opinions and approaches vary the most in those children with ectopic ureteroceles associated with vesicoureteral reflux.
In the adult, transurethral unroofing of the ureterocele is a reasonable first-line approach, because the development of postoperative vesicoureteral reflux is less problematic than in the pediatric population.
Surgical therapy for both pediatric and adult ureteroceles may include any of the following:
Endoscopic puncture
Incision or transurethral unroofing of the ureterocele
Upper pole heminephrectomy
Excision of ureterocele and ureteral reimplantation
Nephroureterectomy
Endoscopic puncture
Endoscopic puncture is the least invasive method for ureterocele decompression. This is an ideal method for dealing with a neonate with ureterocele-induced obstructive uropathy and sepsis. It may also be performed safely in adults with a symptomatic ureterocele. Other indications include a single-system intravesical ureterocele with obstruction or a duplex-system ureterocele with indeterminate function of the affected renal moiety. Performed via the cystoscope, a small puncture is created at the base of the ureterocele. This technique is often done using a 3F Bugbee electrode. The thermal damage to the surrounding tissue subsequently results in an opening larger than 3F. Creation of multiple punctures using a holmium YAG laser with 0.5–0.8 joule energy has also been reported.[14]
With a thick-walled ureterocele, either a larger puncture or incision, or multiple punctures may be required to establish drainage. Multiple endoscopic procedures may be required to successfully decompress an ectopic ureterocele.[15]
This procedure also allows palliative decompression in children at high risk (secondary to concurrent medical illness), so that definitive reconstruction can be delayed until an adequate healing period has occurred. Antibiotic prophylaxis should be administered postoperatively in pediatric patients until voiding cystourethrography (VCUG) can be performed to assess for vesicoureteral reflux. Patients with ectopic ureterocele and duplicated system are significantly more likely to require a secondary procedure, most often because of reflux. Endoscopic treatment provides definitive therapy in only 10-40% of patients with ectopic ureteroceles, compared with 80-90% of patients with a single-system intravesical ureterocele.
Transurethral unroofing
Transurethral unroofing of a ureterocele in adults reliably achieves decompression and allows effective treatment of infection and calculi in symptomatic ureteroceles. Low transverse incision of the ureterocele, as described by Monfort and colleagues,[15] creates a "flap-valve" effect and minimizes the chance of subsequent vesicoureteral reflux compared with transurethral resection of the ureterocele roof. The actual incidence of reflux after endoscopic unroofing in ureteroceles in adults is unknown because a large prospective adult series is lacking. However, several case reports have alluded to the fact that the incidence of reflux appears to be proportional to the type of incision made.
Vesicoureteral reflux in adults is not routinely treated with ureteral reimplantation. Rather, these patients are monitored expectantly, and the need for reimplantation is tailored to the individual. Data on the use of bulking agents for treatment of adult vesicoureteral reflux in these situations are lacking. The potential for vesicoureteral reflux limits the use of endoscopic unroofing in children.
Upper pole heminephrectomy and partial ureterectomy
Upper pole heminephrectomy and partial ureterectomy with ureterocele decompression involves removal of the upper pole of the kidney, as well as the affected proximal ureter to the level of iliac vessels. The remaining distal ureterocele is not excised but rather is decompressed. This is the definitive treatment in patients with an obstructed ectopic ureterocele and a dysplastic upper pole, but without associated vesicoureteral reflux. If reflux is present preoperatively, the distal ureter should be ligated. Upper pole heminephrectomy and partial ureterectomy with ureterocele decompression is a reasonable alternative for adults in whom transurethral ureterocele unroofing has failed due to technical or anatomical difficulties.
Upper pole heminephrectomy and partial ureterectomy with ureterocele decompression has been reported to cause spontaneous resolution of grade I and II vesicoureteral reflux in 60% of cases, while higher grades of reflux necessitated bladder reconstruction in 96% of cases. While upper pole heminephrectomy provides effective decompression, the risk for subsequent bladder surgery may be significant, especially if reflux is present.
Factors that may predict the likelihood of future surgical intervention include the following:
High-grade reflux (grades III, IV, V)
Complications resulting from remaining stump of upper ureter (ie, UTI, calculus)
Poor detrusor backing behind the remaining ureterocele
Upper pole heminephrectomy is an excellent first-line procedure for the relatively rare child with minimally functioning upper pole and no reflux. However, the patient and family should be counseled regarding the potential need for further surgical procedures.
Ureteropyelostomy
Ureteropyelostomy is an operation that joins the upper pole ureter to the lower pole renal pelvis. This is preferred in both children and adults if the affected renal unit demonstrates significant function on nuclear renography and there is no associated vesicoureteral reflux. Alternatively, a high ureteroureterostomy may also be performed.
Excision of the ureterocele and ureteral reimplantation
Ureterocele excision with ureteroneocystostomy is indicated as a primary procedure if the patient has significant vesicoureteral reflux in the lower pole moiety and/or significant contralateral vesicoureteral reflux. Both ipsilateral ureters may be reimplanted within a common sheath or via ureteroureterostomy. Note that common sheath reimplantation has the distinct disadvantage of reimplanting a very dilated distal ureter into the small bladder of an infant. The decision whether to taper the ureters must be made on an individual basis. This operation is commonly delayed until the child is older (aged approximately 2 y) following endoscopic puncture as an infant. Ureteral reimplantation is not commonly performed in adults as most patients respond favorably to endoscopic unroofing of the ureterocele.
In the pediatric population, ureterocele excision and ureteral reimplantation is commonly a secondary procedure (after previous heminephrectomy or endoscopic incision of a ureterocele) because of recurrent urinary tract infections, voiding disturbance, persistent vesicoureteral reflux, or obstruction. Significant vesicoureteral reflux on initial VCUG usually indicates that lower-tract reconstruction will be necessary. Of note, if ureteral reimplant is performed as first-line treatment in the appropriately selected patient, the rate of secondary surgery is low.
Nephroureterectomy
Nephroureterectomy is performed in patients with single-system ureterocele and a poorly functioning kidney. A retrospective review reported a 4% incidence of nephroureterectomy in children with single-system ureterocele and nonfunctioning renal unit.[16] The traditional method of correcting an ectopic ureterocele in a duplex system has been to perform a total reconstruction. This involved a bladder-level operation with ureterocele excision and reimplantation of the lower pole ureter, followed by a flank incision and upper pole heminephrectomy. Since most ureteroceles typically present in young children, total reconstruction was technically challenging, and complications were common.
The goals of the preoperative evaluation of the ureterocele include the following:
Detailed delineation of upper and lower urinary tract anatomy
Estimation of differential function of all renal moieties
Determination of the presence of obstruction (anatomic or functional) and/or vesicoureteric reflux
After a preoperative evaluation has been completed, one must obtain a properly informed consent and preoperative laboratory studies. Patients and parents should be counseled regarding the possibility that additional procedures will be required.
When an upper tract approach is planned, preoperative function of the involved moiety and appearance of the renal parenchyma intraoperatively contribute to the decision whether to perform heminephrectomy or renal-sparing surgery (ie, ureteroureterostomy or ureteropyelostomy).
The principles of successful ureteral reimplantation, with or without ureteral remodeling and bladder reconstruction, are as follows:
Protection of contralateral ureteral orifice
Adequate ureteral exposure and mobilization
Gentle handling of the tissue and meticulous preservation of blood supply
Creation of a valvular mechanism with a submucosal tunnel with a ureteral length-to-diameter ratio of 5:1
Endoscopic incision of ureterocele
This is the least invasive technique. The patient is placed in dorsolithotomy position; infants can be placed in the supine position with the lower extremities frog-legged to facilitate urethral exposure. Incision of the ureterocele is performed via the cystoscope. Using a small Bugbee electrode (3F) on cutting current, a small puncture is created at a low point just above the base of the ureterocele.
Upper pole heminephrectomy and partial ureterectomy with ureterocele decompression
The patient should be placed in the flank or lateral decubitus position. A Foley catheter is placed to straight drainage. A flank incision is made off the 12th rib. The kidney and proximal ureter are mobilized. The non-functioning upper pole moiety is excised. There is no need to dissect out the renal hilum. Manual compression of the kidney provides adequate vascular control. Next, excise the upper pole ureter to the level of the iliac vessels. Dissect on the upper pole ureter to avoid injury to the lower pole ureter. Use a catheter to decompress the distal ureterocele. If there is no reflux into the ureterocele, the stump is left open. If reflux is present, the ureter should be ligated. Irrigate the wound and leave a small drain in the pelvis.
Ureteropyelostomy
The patient is positioned supine and a Foley catheter inserted. An anterior subcostal incision is created. Staying extraperitoneal, both ureters are dissected. Incise the upper pole ureter laterally and incise the lower pole renal pelvis medially. Anastomose the upper pole ureter to lower pole renal pelvis. Insertion of a double J stent or a feeding tube is optional.
Excision of ureterocele with ureteral reimplantation
The patient is placed in a supine position. A Pfannenstiel incision is made. The bladder is opened and the ureteral orifice and the ureterocele are identified. Both ureteral orifices are cannulated with infant feeding tubes. Circumscribe and remove the root of the distal ureterocele followed by the floor of the ureterocele. Close the defect in the detrusor. Ureters may be reimplanted within the common sheath or via ureteroureterostomy, with or without tapering of the ureter.
Nephroureterectomy
Nephroureterectomy involves the excision of the ureterocele, ureter, and the ipsilateral renal moiety. This is followed by reimplantation of the lower pole ureter. This approach requires two separate incisions (flank and lower abdominal) and is associated with fairly high morbidity. This type of total reconstruction is not commonly used at present; however, with the advent of laparoscopic techniques, the morbidity of this approach has been reduced.
Intravenous antibiotics are continued until the patient is discharged from the hospital. Pediatric patients should be placed on prophylactic antibiotics until VCUG demonstrates resolution of reflux. Urethral catheters are removed when the urine has cleared. Depending on the operation, hospital stay ranges from 1-4 days. Patients undergoing endoscopic procedures are often discharged on the same day. If an internal stent is placed, it is removed 3-6 weeks after surgery. Postoperative imaging studies such as renal ultrasonography and VCUG are usually obtained 6-8 weeks postoperatively, as dictated by individual clinical scenario or postoperative complications.
The complications of ureterocele therapy vary with the surgical procedure used.
Endoscopic incision of ureterocele
This is infrequently definitive therapy, except in cases of a single-system intravesical ureterocele.[17] Iatrogenic vesicoureteral reflux, especially in extravesical ureteroceles, can occur.
Upper pole heminephrectomy
This technique has the highest risk of -intraoperative blood loss. Vascular compromise of lower pole with potential loss of kidney function can occur. The need for further lower tract reconstruction due to persistent reflux, infection, or failure to decompress the ureterocele is a possible complication.
Excision of ureterocele and ureteral reimplantation
Postoperative complications include the following:
Problematic hematuria and/or bladder spasms
Damage to bladder neck or continence mechanism
Injury to the contralateral ureteral orifice
Compromise of blood supply to the lower pole ureter
Christopher S Cooper, MD, FACS, FAAP, Professor with Tenure and Vice Chair, Department of Urology, Tyrone D Artz Chair in Urology, Professor, Department of Pediatrics, Director of Pediatric Urology, Senior Associate Dean for Medical Education and Research Facility, Children's Hospital of Iowa, University of Iowa, Roy J and Lucille A Carver College of Medicine
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Chief Editor
Edward David Kim, MD, FACS, Professor of Urology, Department of Urology, University of Tennessee Graduate School of Medicine; Consulting Staff, University of Tennessee Medical Center
Disclosure: Nothing to disclose.
Additional Contributors
Michael Grasso, III, MD, Professor and Vice Chairman, Department of Urology, New York Medical College; Director, Living Related Kidney Transplantation, Westchester Medical Center; Director of Endourology, Lenox Hill Hospital
Disclosure: Received consulting fee from Karl Storz Endoscopy for consulting.
Shlomo Raz, MD, Professor, Department of Surgery, Division of Urology, University of California, Los Angeles, David Geffen School of Medicine
Disclosure: Nothing to disclose.
Acknowledgements
Angela M Arlen, MD Chief Resident, Department of Urology, University of Iowa, Roy J and Lucille A Carver College of Medicine
Angela M Arlen, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American Urological Association, and Society of Women in Urology
Disclosure: Nothing to disclose.
Leslie Tackett McQuiston, MD, FAAP Assistant Professor of Surgery (Urology) Dartmouth Medical School; Staff Pediatric Urologist, Dartmouth-Hitchcock Hospital
Disclosure: Nothing to disclose.
Eugene Minevich, MD Assistant Professor, Department of Surgery, Division of Pediatric Urology, University of Cincinnati College of Medicine
Intravenous urogram demonstrating left hydroureteronephrosis due to a ureterocele represented by the round filling defect located at the left base of the bladder (Courtesy of Steven Kraus, MD, Cincinnati, Ohio)
Intravenous urogram demonstrating left hydroureteronephrosis due to a ureterocele represented by the round filling defect located at the left base of the bladder (Courtesy of Steven Kraus, MD, Cincinnati, Ohio)
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