UPJ OBSTRUCTION

PREPARED BY :DR.TALAL BALLOUTSUPERVISED BY:DR.WALED ZALLOUM

URETER ANATOMY

The ureters are bilateral tubular structures responsible for transporting urine from the renal pelvis to the bladder .

They are generally 22 to 30 cm in length with a wall composed of multiple layers:

-transitional epithelium -lamina propria-smooth muscle(inner longitudinal and outer

circular) Adventitia.-

URETER ANATOMY

Sites of ureteral narrowing:-Ureteropelvic junction. -Junction as the ureter crosses the iliac

vessels.

-Ureterovesical junction.:

URETER ANATOMYAnatomic Relationships:-Anteriorly, the right ureter is related to the ascending colon,cecum, colonic mesentery, and appendix. -The left ureter is closely related to the descending and sigmoid colon and their mesenteries. -Approximately a third of the way to the bladderthe ureter is crossed anteriorly by the gonadal vessels.-UPJ lies posterior to the renal artery and vein, It then lies anterior to the psoas muscle .-As it enters the pelvis the ureter crosses anterior to the

iliac vessel.-In the female pelvis, the ureters are crossed anteriorlyby the uterine arteries and are closely related to the

uterine.

URETER ANATOMY

:BLOOD SUPPLYTo upper ureter branches originate from therenal artery, gonadal artery, abdominal aorta, and

common iliac artery. After entering the pelvis, additional small arterial branches to the distal ureter may arise from the internal iliac artery or its branches, especially the vesical and uterine arteries, but also fromthe middle rectal and vaginal arteries.

URETER ANATOMY

-The venous and lymphatic drainage of theureter parallels the arterial supply. -ureteral lymphatic drainage varies by ureteral level: -In the pelvis, ureteral lymphatics drain to internal,

external, and common iliac nodes. -In the abdomen the left para-aortic lymph nodes are the primary drainage site for the left ureter,

whereas the abdominal portion of the right ureter is drained primarily to right paracaval and interaortocaval lymph nodes.

URETER ANATOMY

NERVE SUPPLY Sympathetic- T10-L1 Parasympathetic- S2-S4

EPIDEMIOLOGY-Most common site of urinary tract

obstruction in children . -Majority are discovered antenatally:-It is the most common anatomical

cause of antenatal hydronephrosis – Boys > girls – Most cases on the left – 10-40% bilateral

PATHOPHYSIOLOGY

-It is caused by anatomic lesions or functional disturbances that restrict urinary flow resulting in hydronephrosis.

- Most cases are thought to be due to partial obstruction, because complete obstruction results in rapid destruction of the kidney.

- In some cases, partial obstruction may also lead to progressive deterioration of renal function.

ETIOLOGY

-It is both congenital and acquired conditions.Usually caused by intrinsic stenosis of

the proximal ureter, and less commonly by extrinsic compression of the UPJ.

ETIOLOGY congenital :Intrinsic narrowing:• In most cases of UPJ obstruction, the upper

segment of the ureter is narrowed or kinked, resulting in obstruction of urinary flow.

• Although the underlying mechanism is not proven, it is thought that there is an embryologic disruption of the proximal ureter that alters circular musculature development and/or collagen fibers, and composition between and around the muscular cells.

ETIOLOGY

Extrinsic narrowing:In about 10 % of pediatric UPJ

obstruction, an aberrant or accessory renal artery or arterial branch may cross the lower pole of the kidney, resulting in compression of the UPJ and blockage of urinary flow.

ETIOLOGY

:acquired-vesicoureteral reflux- Benign lesions such as fibroepithelial

polyps.- stone disease.- Postinflammatory or postoperative

scarring or ischemia.-

CLINICAL PRESENTATION• Historically presented as a palpable

mass.– Newborn:• Antenatal hydronephrosis 80% • UTI, hematuria, failure to thrive, feeding

difficulties, sepsis,azotemia.– Later in life:• 30% diagnosed after UTI • 25% diagnosed after hematuria • Episodic abdominal pain and vomiting

due to intermittent obstruction

DIAGNOSIS• It is generally suspected when imaging

studies, usually ultrasonography, demonstrate hydronephrosis.

• The diagnosis is confirmed by diuretic renography.

DIURETIC RENOGRAPHY• It (renal scan and the administration of a

diuretic) is used to diagnose urinary tract obstruction.

• It measures the drainage time from the renal pelvis (referred to as washout) and assesses total and each individual kidney's renal function.

•The washout measurement correlates with the degree of obstruction.

In general, a half-life greater than 20 minutes to clear the isotope from the kidney is considered indicative of obstruction.

COMPUTED TOMOGRAPHIC SCAN (CT)

- It is an alternative to ultrasonography in the symptomatic child.

-It is not the preferred modality due to its radiation exposure.

- In UPJ obstruction, the CT scan typically shows hydronephrosis without a dilated ureter.

TC99M-DIETHYLENETRIAMENEPENTACETIC ACID (99MTC-DTPA) SCAN

-help differentiate UPJ obstruction from multicystic kidney and determine the level of obstruction.

- Multicystic kidneys rarely reveal concentration of this isotope. When uptake is seen, the areas of functioning tissue are initially discrete and are usually medial to the bulk of the mass, which

itself remains a “cold” area.In contrast, neonatal kidneys with UPJ obstruction generallyexhibit good concentration of the isotope. Furthermore, even with severe obstruction in which only a cortical rim

remains, uptake of the isotope will be seen peripherally in the cortex.

99MTC-MAG3

-It provides quantitative data regarding differential renal function and obstruction, even in hydronephrotic renal units.

-There is evidence that the diuretic renography using MAG-3 is a most accurate study for patients with UPJ obstruction following therapeutic intervention

VOIDING CYSTOURETHROGRAM (VCUG)-It is performed in patients with hydronephrosis to

confirm the presence or absence of VUR of both the affected and contralateral kidneys.

-10% of patients with UPJ obstruction have contralateral low-grade vesicoureteral reflux.

-Identification of VUR is important because children with concurrent VUR and UPJ obstruction may be at higher risk for severe infection.

FOLLOW-UP• U/S on day 2 - 3 of life Persistent

hydronephrosis. • VCUG to evaluate PUV or VUR.• Prophylactic antibiotics if VUR present.• No PUV or VUR - repeat U/S and diuretic renal

scan at 1 month .• Continued hydro - surgery vs. observation .• observation - U/S and/or renal scan every 3-4

months for 1 year and then every 4-6 months.

DIFFERENTIAL DIAGNOSIS• It includes other causes of

hydronephrosis. • Imaging studies differentiate UPJ

obstruction from the following conditions:

-Vesicoureteral reflux (VUR) - Other urological anomalies including

posterior urethral valves, congenital megaureter, ureterocele,,,,.

MANAGEMENT

Conservative:

• Principles:– 50% of antenatal hydro resolved postpartum .– observations that asymptomatic hydronephrosis can resolve

spontaneously.

• Studies with infants with renal function >35-40% in the affected kidney and variable washout patterns:

– “Rule of 1/3” - 1/3 stay the same, 1/3 improve, 1/3 worsen.

SURGICALIndications for Surgical Intervention:• Presence of symptoms associated with

the obstruction.• Impairment of overall renal function.• Progressive impairment of ipsilateral

function.• Development of stones or infection .• Hypertension.

OPEN PYELOPLASTY– Gold Standard.

– Dismembered pyeloplasty is the most common

(Anderson Hynes ).Advantages:-This approach can be used regardless of whether the ureteral insertion is

high onthe pelvis or already dependent. -It also permits reduction of a redundant pelvis or straightening of a

tortuous proximal ureter.-anterior or posterior transposition of the UPJ can be achieved when the

obstruction is due to accessory or aberrant lower pole vessels.-only a dismembered pyeloplasty allows complete excision of the anatomically or functionally abnormal UPJ itself.

Disadvantages: Dismembered pyeloplasty is not well suited to UPJ obstruction associated

with lengthy or multiple proximal ureteral strictures or to patients in whom the UPJ obstruction is associated with a small intrarenal

pelvis.

• FOLEY V-Y-PLASTY

Best for high inserting ureter-Best with relatively small pelvis---contraindicated : a-when transposition of lower pole

vessels is necessary. b-redundant renal pelvis

• SPIRAL FLAP

-Best for large, readily accessible extrarenal pelves in which the ureteral insertion is

already in a dependent position.Best for long segment of ureteral

narrowing or stricture.

URETEROCALYCOSTOMY

-Used when small intrarenal pelvis-When the UPJ is associated with

rotational anomalies such as horseshoe kidney .

-ureterocalycostomy is a well-accepted salvage technique for the failed pyeloplasty.

• ENDOPYELOTOMY

– Antegrade or retrograde endopyelotomy-Direct vision antegrade approach is most

common-dilation balloon with hot wire– 86% success in adults– Slightly less effective in childrenContraindications include relatively long

areas ofobstruction

• LAPAROSCOPIC PYELOPLASTY

– Same indications as open or endourologic procedures

– Dismembered pyeloplasty is most common procedure performed :

• Without crossing vessels, may do any number of flap procedures

• Up to 94% success rate, similar to open pyeloplasty

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