Ectopic Ureter & Ureterocele: Comprehensive Overview & Management

Ectopic Ureter & Ureterocele 

• These are distinct entities but share some common features, as pointed out below.
• Same underlying developmental mechanism
• A continuum of embryological development.
• They have similar clinical presentations.
• Approached in a similar manner.
• Management has slight variation for these two conditions.

What is Ectopic Ureter?

Ectopic Ureter: Any ureter, single or duplex, that does not enter into the trigonal area of the bladder. In a duplex system, inevitably the upper pole ureter, because of its budding from the mesonephric duct later than the lower pole with incorporation into the developing urogenital sinus.

What is Duplication of Renal Ureter?

• If the upper pole and the lower pole of the same kidney are getting drained by two separate ureters. This situation is known as duplication of the renal ureter.
• The incidence of the duplication of the ureter is 1 in 150 births.
• This is more common in the left kidney, and females are more affected than males.
• Incomplete duplex ureter: When two separate ureters originate from the upper and lower pole of the kidney but then join and open as a single ureter in the bladder
• Complete duplex ureter: Here the two ureters separately open into the bladder. One ureter opens into the bladder, whereas the other one opens ectopically. This is known as complete duplex ureter
• A complete duplex ureter is usually associated with ureterocele.

Also read: Megaureter in Children: Causes, Diagnosis & Treatment Options

Weigert Meyer Rule

• As discussed already, in a duplex kidney there are two poles, upper and lower.
• The ureter draining the upper pole of the kidney opens caudally and medially at an ectopic location.
• This ureter, which is opening ectopically, is generally stenotic.
• As they are stenotic, they are associated with obstruction.
• On the other hand, the ureter that is coming from the lower pole is opening cranially and laterally.
• The ureters that are opening laterally are associated with reflux. So, the ureter opening from the upper pole is stenotic, and the one from the lower part is associated with reflux.
• As the ureter from the upper pole is stenotic and obstructive, it will cause hydronephrosis.
• This will cause a change in the back pressure at the upper pole of the kidney, leading to a non-functional upper pole.

Opening of Ectopic Ureter

In Males

• In males, it can open many sites, like the prostatic urethra, seminal vesicle, neck of the bladder, and epididymis.
• But the most common site is prostatic urethra.
• It is important to remember that the ectopic ureter will always open proximal to the external urethral sphincter. So the men will never experience incontinence. Male patients will show the presentation of urinary tract infection (UTI).

In Females

• It opens at the distal part of the urethra or in the vagina.
• In females there is only the internal sphincter, and the urethral opening is distant from it, so the presenting feature in females is always incontinence.
• Females will describe the situation as continuous dribbling while the bladder filling is normal.
• As the normal kidney is working properly, that's why the patient has a normal sense of bladder. In females, it can open anywhere from the bladder neck to the perineum and into the vagina, uterus, and even the rectum.
• Ureter may also open into the Gartner duct cyst. It is the remainder of the Wolffian duct from which the ureter buds.
• If the Gartner duct cyst ruptures, vaginal communication can happen, and this causes incontinence. Though it is a rare situation.

Single System Ectopic Ureters & Ureteroceles

• Ectopic ureters are not always associated with duplex systems; they may also be present in single systems.
• In this situation, the USG shows apparently the absence of a kidney. This may be because the ureter is stenotic or obstructive. OR may be having a small, poorly functioning renal unit on CT urogram.
• Rarely, bilateral single system ectopic ureters may be associated with hypoplastic bladder & bilateral renal abnormalities or dysplasia (apparent bladder agenesis).

Also read: Male Infertility: Causes, Diagnosis, Treatment & Semen Analysis Guidelines

What is Ureterocele?

• It is a condition where cystic dilatation of the terminal intravesical ureter occurs.
• Intravesical Ureterocele: It is contained entirely within the bladder. It may prolapse into the urethra during voiding; that's why it may cause bladder outlet obstruction.
• Ectopic Ureterocele: If any portion is permanently situated at the bladder neck or urethra regardless of the position of the orifice (bladder, bladder neck, or urethra), it is called ectopic ureterocele.
• They do not form entirely within the urethra, nor do they attach to wolffian duct structures.
• It may happen in single or duplex systems. If it occurs in the duplex system, it will invariably affect the upper pole of the kidney.

Classification of Ureteroceles

• Ureteroceles can be classified according to their position, location of the ureteric orifice, and renal collecting system.
• Based on position, they can be intravesical or prolapsing.
• Intravesical means it is still in the bladder. In prolapse, it may be prolapsed into the urethra.
• Based on the location of the orifice, it can be simple or ectopic.
• Even when the ureter opens normally into the bladder it can still be associated with ureteroceles. Mostly it is associated with ectopic but may also be with normal ureter system bladder.
• On the basis of the renal collecting system, it can be classified into a single or duplex system.

Classification Based on the Features of the Affected Ureteral Orifice

A: Sphincter Stenosis ectopic ureterocele.

B: Cecoureterocele lumen extends distal to the orifice as a long tongue beneath the ureteral submucosa. The orifice communicates with the lumen of the bladder and is large and incompetent.

• Stenotic Ureteroceles: Located within the bladder with an obstructing orifice.
• Sphincteric Ureterocele: It refers to those that 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: These have the characteristics of both stenotic and sphincteric ureteroceles.
• Cecoureterocele: There is elongation beyond the ureterocele orifice by tunneling under the trigone and the urethra.

Churchill's Functional Classification System

This classification is based on the impact of ureterocele on the upper urinary tract, including all renal units. There are three types in this classification:

• Only the upper pole is affected.
• Entire ipsilateral kidney involved.
• The contralateral system is also at risk due to bladder outlet obstruction or reflux.

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Non-Obstructive Ureterocele with Duplication or Ureterocele Disproportion

• It is associated with duplex kidney but affected upper pole & ureter non-dilated and dysplastic. It is not readily detected on most imaging.
• Here the stenotic component is not present, and for this reason the hydronephrosis does not happen, so it cannot be detected early.
• Typical ureterocele is seen in bladder but ipsilateral kidney is completely normal.

Pathophysiology and Embryology

Ureteral bud branch from mesonephric /Wooffian duct

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Extends into nephrogenic blastema (undifferentiated mesenchymal)

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Formation of the entire renal collecting system

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Distal to ureteric bud, mesonephric duct incorporates into UGS

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U.O superolaterally moves to its normal position on trigone

• The time point in which the ureteric bud is getting incorporated into the urogenital sinus is associated with these anomalies.
• The distal segment of the mesonephric duct is carried inferomedially and incorporated in the bladder neck.
• In the male fetus, it also develops into seminal vesicles, vas deferens, and epididymis.
• In females, it becomes the Gartner duct located between the vagina and urethra.
• In ureteral duct duplication, two ureteric buds arise from mesonephric duct.
• Lower—earlier insertion into UGS and superolateral location of orifice. It has poor trigonal support and a short intramural tunnel and is predisposed to VUR. As it is entering early into the UGS, it will have a more superolateral position of the opening.
• Upper: In this case the ureter inserts later and low on trigone inferomedially. It inserts ectopically in the bladder neck or ejaculatory duct, seminal vesicle or vas deferens in males, and in Gartner duct in females.
• Ureteral ectopia without the duplication results from delayed incorporation of the distal ureter into the developing bladder.

Also read: Peyronie's Disease and It’s Management

Diagnosis 

• The majority of ectopic ureters and ureteroceles are detected on prenatal USG, even if there is no specific diagnosis.
• Duplex system prenatal diagnosis is difficult, except in dilated upper moiety. So if the hydronephrosis is present in the upper pole, it may help in the detection.

Physical Examination

• It may help in the diagnosis. Patients may have prolapsed ureterocele with characteristic interperennial mass. Ectopic perineal urethral orifice in a child with history of continuous dampness. Both of these features are more common in females.
• Presence of a dilated Gartner duct cyst, though it is rare in nature. (shown in the above diagram)
• Palpable dilated upper pole of ectopic ureter or ureterocoele in a relaxed infant may be seen.

Ultrasound

• Typical findings include a dilated upper pole with ureteral dilation or a dilated single system.
• Bladder images differentiate ureterocele from ectopic ureter. Sometimes the ectopic ureter (pseudo ureterocele) impinges on the bladder and appears like a ureterocele. This could be differentiated well in ultrasound.
• There is a thin-walled cystic dilation within the bladder not extending beyond its walls. As shown in the above diagram, the cyst is very thin-walled and within the bladder. Whereas in pseudo-ureterocele it will go beyond the wall of the bladder and the lining will be thicker.

MRI

• It provides the most definitive imaging.
• Currently, it is recommended to patients with distorted or complex anatomy.

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Renal Function – Nuclear Imaging

• The gold  standard for renal function assessment is a DMSA scan.
• The primary role of this is to detect the functional role of the upper pole, the status of other renal moieties, and if lower pole reflux or hydronephrosis (HN) is present in any unit.
• To assess the drainage function in ureteroceles in which the observation is planned, a diuretic renal scan replaces DMSA and provides both functional and drainage information.

IVU

• This is a less useful baseline study.
• Here the functional analysis is only qualitative in nature.
• The 'cobra-head' 'or' 'spring-onion' configuration of ureterocele at the bladder level could be detected by this process.

VCUG of Ureterocele

• Voiding cystourethrography (VCUG): If this is done, it will show   filling defect.
• When there is a duplex kidney with a non-functional upper pole, it will appear as drooping lily.

Endoscopic Evaluation

• It may be used to assess the character of the urethra, bladder neck, and trigone relative to ureterocele or ectopic ureter.
• The location of the other ureteral orifices should be documented.
• Orifice of affected ureter should be sought but may not be identified.
• The urethra should be examined carefully for orifice if not seen in the bladder.
• The appearance of the ureterocele will vary with bladder filling. It will start with a little filling and slowly increase the bladder volume.
• The lowest portion is the best site for incision. While it is fully distended, the lowest portion is the most optimum position for incision.
• Retrograde contrast can confirm the ureterocele disproportion and unusual connection with the genital ducts.

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Management 

• The aim of the management is to preserve renal function.
• Elimination of infection, obstruction, and reflux.
• Maintenance of urinary continence.
• Minimizing surgical mortality.

Acute Decompression 

Indications

• Ureterocele producing bladder outlet obstruction or severe bilateral upper tract obstructions.
• Severe urosepsis.
• When sepsis is not responding to appropriate therapy. 

Methods

• For ureterocele, transurethral incision.
• For ectopic ureters, end ureterostomy near the bladder. For this, the end of the ureter needs to be brought outside like a stoma.

Definitive Surgical Options 

• For ectopic ureter common sheath reimplementation or ureteroureterostomy (attach two ureters) in either the low, distal, or high proximal near the renal pelvis.
• For ureterocele, incision (TUI) can be done. If that does not help, then ureterocele excision can be done. And when the patient has an ectopic ureter in association with ureterocele, then common sheath reimplementation or ureteroureterostomy can be done.

Transurethral Incision (TUI)

• Transverse incision through full thickness of ureterocele wall using cutting current as distally and close to the bladder floor as possible.
• The other things that could be used are Bugbee electrodes, angled tip wires, cold knives, resectoscopes with Collins hot knives, or laser incisions.
• A deep incision in the thick wall should be done, and it needs to look for a urine jet or inner urothelium.
• Ectopic Ureterocele: Longitudinal incision from the intravesical into urethral portion or maybe two incisions should be done.

Follow Up

• After the management of the disease the patients are asked to follow up USG after 4-6 weeks to assess the degree of decompression.
• VCUG at 2-3 months to determine status of lower pole reflux.
• The risk of reoperation is high with extravesical ureteroceles and lower pole reflux (persisting or new).

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Temporary End Ureterostomy for Ectopic Ureter

• When there is ectopic ureter in infants with sepsis and massive dilation, there would be a temporary end ureterostomy.
• The advantage is that it causes acute decompression to manage sepsis and permits later assessment (in 4 months or 6 months of age) of any function in the affected renal unit before definitive management.

Hope you found this blog helpful for your NEET SS Surgery Urology Preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.