Download Anomalies of the Upper Urinary Tract

‫‪Anomalies of the Upper‬‬
‫‪Urinary Tract‬‬
‫د‪ .‬جاسم الميالي‬
‫اختصاص الجراحة البولية‬
KIDNEY DEVELOPMENT
The embryonic kidneys are, in order of their
appearance, the pronephros, the
mesonephros , and the metanephros. The
first two kidneys regress in utero, and the
third becomes the permanent kidney.
The ureteric bud(UB) arising from the
mesonephic duct at the end of the fourth
week, grows cranially, acquiring a cap of
metanephric blastema by the fifth week.
The developing metanephric tissue and UB
migrate cephalad, rotating medially on its
long axis. The entire process is completed
by the eighth week of gestation.
The nephron, which consists of the
glomerulus, proximal tubule, loop of Henle,
and distal tubule, is thought to derive from
the metanephric blastema, while the
collecting system, consisting of collecting
ducts, calyces, pelvis and ureter, is formed
from the ureteric bud.
Anomalies of the kidney
• ANOMALIES OF NUMBER:
Bilateral Renal Agenesis.
Unilateral Renal Agenesis.
• ANOMALIES OF ASCENT:
Simple Renal Ectopia.
Horseshoe Kidney.
• CYSTIC DISEASES OF THE KIDNEY:
Bilateral Renal Agenesis
-The incidence of BRA is rare. More common in male.
-The characteristic Potter facies and the presence of
oligohydramnios are pathognomonic .
-Renal ultrasonography demenstrate absence the
kidneys .
-About 50% of the affected neonates are stillborn. Of
those neonates who are born alive most do not survive
beyond the first 48 hours due to respiratory distress
associated with pulmonary hypoplasia.
Potter facies
Unilateral Renal Agenesis
Unilateral renal agenesis occurs once in 1000 births .
More common in males. It more frequently on the left
side.
Abnormalities of the contralateral ureter including
ureteropelvic junction obstruction in 10% and
vesicoureteral reflux in 30%.
Anomalies of other organ systems are found frequently
in affected individuals. The more common sites involve
the cardiovascular (30%), gastrointestinal (25%).
There are no specific symptoms that suggest an absent
kidney.
- Abdominal ultrasonography show absent of one
kidney.
-The diagnosis of URA usually can be confirmed with a
DMSA scan showing absent uptake of the isotope on
one side.
Simple Renal Ectopia
When the mature kidney fails to reach its normal location in the
“renal” fossa, the condition is known as renal ectopia. An ectopic
kidney can be found in one of the following positions: pelvic, iliac,
abdominal and contralateral.
50% percent of ectopic kidneys have hydronephrotic collecting
system which result from obstruction at the ureteropelvic or the
ureterovesical junction or from reflux grade III or greater, or from
the malrotation alone.
The ectopic kidney is no more susceptible to disease than the
normally positioned kidney, except for the development of
hydronephrosis .
Horseshoe Kidney
Horseshoe kidney occurs in 1 of 400 of the population.
It is found more commonly in males.
In 95% of cases, the kidneys join at the lower pole, rarely isthmus
connects at upper poles.
Generally, the isthmus is bulky and consists of parenchymatous
tissue with its own blood supply . Occasionally it is composed of
fibrous tissue.
Migration is usually incomplete, with the kidneys lying lower in
the abdomen than normal. It is presumed that the inferior
mesenteric artery prevents full ascent by obstructing the
movement of the isthmus
Horseshow kidney
CYSTIC DISEASES OF THE KIDNEY
The kidney is one of the most common sites in
the body for cyst formation.
Cystic Diseases of the Kidney may be:
-inheritable : polycystic kidney disease.
-noninheritable :multicystic dysplastic kidney,
Simple cysts.
AUTOSOMAL RECESSIVE (INFANTILE)
POLYCYSTIC KIDNEY DISEASE
It is rare disease. Genetics:mutations of a single gene
located on chromosome 6.
Clinical Features:
Affected children typically present in utero with
enlarged, echogenic kidneys. Oligohydramnios is
common because of the lack of normal urine
production by the fetus. The infant often displays
Potter facies and deformities of the limbs and may
have respiratory distress as a consequence of
pulmonary hypoplasia
Treatment:
No cure has been found for ARPKD.
about 50% of the affected individuals die shortly after
birth as a result of uremia or respiratory failure. Patients
who survive may require treatment for hypertension,
renal and hepatic failure.
AUTOSOMAL DOMINANT(ADULT)POLYCYSTIC
KIDNEY DISEASE
Incidence of approximately 1 in 1000 live births.
Genetics: mutation in the genes PDK1 (chromosome
16) and PDK2(chromosome 4).
A number of associated anomalies are common,
including cysts of the liver, pancreas, spleen, and
lungs; aneurysms of the circle of Willis (berry
aneurysms); colonic diverticula; aortic aneurysms; and
mitral valve prolapsed.
Clinical Features:
Typically, signs or symptoms occur between the ages
of 30 and 50 years ,these include hematuria, flank pain
, gastrointestinal symptoms (perhaps secondary to
renomegaly or associated colonic diverticula), and
hypertension.
Evaluation:
-family history
-Abdominal ultrasonography may reveal renal cysts
as well as cysts in other organs.
-CT or MRI : helpful in some cases and often is
superior to ultrasonography for detecting cysts in
organs other than the kidney.
Treatment :
No known cure at this time. Current therapy is directed
toward control the complications of ADPKD and
delaying the onset of ESRD.
- controlling the blood pressure, Chronic pain treated
by medication ,if not respond treated by cyst deroofing.
- infection, stone treated accordingly.
- Renal failure treated by hemodialysis or renal
transplant.
MULTICYSTIC DYSPLASTIC KIDNEY
Multicystic dysplastic kidney is a developmental
anomaly resulting in multiple cysts of variable sizes,
occupi the kidney without normal renal parenchyma.
Etiology:
- obstruction theory: multicystic kidney is an extreme
form of obstructive hydronephrosis that occurs
secondary to atresia of the ureter or renal pelvis.
-ureteric bud theory: MCDK may result from abnormal
interaction between the ureteric bud and metanephric
mesenchyme.
The contralateral kidney frequently is abnormal. For
example, contralateral ureteropelvic junction
obstruction is found in 10% of infants with MCDK, and
contralateral vesicoureteral reflux is seen in 30% of
infants
- Abdominal ultrasonography.
-radioisotope studies: no uptake of isotope.
SIMPLE RENAL CYSTS
Simple renal cysts are the most common cystic lesions
found in the human kidney.
Clinical Features:
they are asymptomatic and discovered incidentally on
ultrasonography, CT. However, cysts can produce an
abdominal mass or pain, hematuria and hypertension
.
To diagnose a benign simple cyst on
ultrasonography, it should
(1) have no internal echoes,
(2) have a sharply defined, thin, smooth wall,
(3) spherical or oval.
When these criteria are not met, CT with
contrast enhancement must be performed
SIMPLE RENALCYSTS(U/S)
MEGAURETERS
It mean dilated ureter more than normal.
Two pathologic types:(1) Refluxing megaureter caused by high grade VUR
( primary or secondary VUR).
(2) Obstructive megaureter caused by obstruction of
the distal segmental of the ureter.
Evaluation:
- Ultrasound is the initial study.
- VCUG is subsequently obtained in most cases to rule
out reflux.
- diuretic nuclear renal scan.
Treatment:
according to the cause of megaureter. Obstructive
megaureter treated by excistion of obstructed segment
and reimplantation of the ureter.