Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st Year, 2nd Year, 3rd Year and Final year Surgery 31 Kidney And Ureters PPT-Powerpoint Presentations and lecture notes
Kidney and Ureters :
Agenesis, Horseshoe kidneys,
congenital cysts, Megaureter,
Ectopic ureter, Ureterocele
Dept Of Surgery
Bilateral Renal Agenesis
? Bilateral Renal Agenesis was first recognized in 1671 by
Wolfstrigel
? Can occur secondary to a defect of the wolffian duct, ureteric
bud, or metanephric blastema
? Bilateral agenesis occurs in 1 of every 4000 births
? Male predominance
? 40% of the affected infants are stillborn
? Children who are born alive do not survive beyond 48 hours
because of respiratory distress associated with pulmonary
hypoplasia
? The adrenal glands are usually normally positioned
? Characteristic Potter facies and presence of oligohydramnios are
pathognomonic
? Complete ureteral atresia is observed in slightly more than 50%
of affected individuals
Potter's facial appearance
Diagnosis
? The characteristic Potter facies and the presence of
oligohydramnios are pathognomonic and should alert for
this severe urinary malformation.
? Amnion nodosum--smal white, keratinized nodules found
on the surface of the amniotic sac--may also suggest this
anomaly
? Anuria after the first 24 hours without distention of the
bladder should suggest renal agenesis
Diagnosis
? BRA has been detected in higher proportion in cryptophthalmos
or Frazer's syndrome, Klinefelter's syndrome , Kallmann's
syndrome, esophageal atresia.
? Renal ultrasonography confirm the presence or absence of
urine within these structures.
? Absence of uptake of the radionuclide in the renal fossa above
background activity confirms the diagnosis of BRA.
? Umbilical artery catheterization and an aortogram defines the
absence of renal arteries and kidneys.
Unilateral Renal Agenesis
? There are no tell tale signs (as with BRA) that suggest an
absent kidney .
? Diagnosis not suspected unless careful examination of the
external and internal genitalia uncovers an abnormality
that is associated with renal agenesis or an imaging study is
done.
? Unilateral agenesis occurs once in 1100 births
? Males predominate in a ratio of 1.8:1
? More frequent on the left side
? Ipsilateral ureter is completely absent in about half
of the patients
? Structures derived from the m?llerian or wolffian
duct are most often anomalous
? Anomalies of other organ systems involve the
cardiovascular (30%), gastrointestinal (25%), and
musculoskeletal (14%) systems
Unilateral renal agenesis to be associated with other
urologic abnormalities in 48% of patients
? Primary vesicoureteral reflux (28%)
? Obstructive megaureter (11%)
? Ureteropelvic junction obstruction (3%)
Diagnosis
? No specific symptoms heralding an absent kidney
? The diagnosis should be suspected during a physical
examination when the vas deferens or body and tail of the
epididymis is missing or hypoplastic vagina is associated with a
unicornuate or bicornuate uterus
? Radionuclide imaging
? No clear-cut evidence that patients with a solitary kidney
have an increased susceptibility to other diseases
Horseshoe kidneys
? Most common of all renal fusion anomalies
? Occurs in 0.25% of the population
? fusion occurs before the kidneys have rotated on
their long axis
The lower poles of the two kidneys touch and fuse as they cross the iliac arteries
? In 95% of patients, the kidneys join at the lower pole; in a
small number, an isthmus connects both upper poles instead
? Calyces normal in number, are atypical in orientation
? Ureter may insert high on the renal pelvis and lie laterally
? Blood supply to the horseshoe kidney can be quite variable
Arteriogram showing a multiplicity of arteries supplying kidney arising from
aorta and common iliac arteries
? UPJ obstruction, causing hydronephrosis, occurs in
one third of individuals
? 60% patients remain asymptomatic for aprox. 10
years
Associated Anomalies
Diagnosis
? Excretory urogram
Prognosis
? 13% have persistent urinary infection or pain
? 17% develop recurrent calculi
? Renal carcinoma has been reported within a horseshoe
kidney in 123 patients
? Incidence of Wilms' tumor in horseshoe kidneys is more
than twice
Congenital cysts
? Kidney is one of the MC
sites in body for cysts
? Arise from the nephrons
and collecting ducts after
they have formed
Cystic Diseases of the Kidney
? Multicystic refers to a dysplastic entity
? Polycystic most inherited, all without dysplasia and all
with nephrons throughout the kidney
? Many of the polycystic kidney disease entities progress
to renal failure
`Snowstorm' appearance of infantile polycystic
disease
Ectopic Kidney
? Kidney not located in usual position
? 1 in 1,000 births, but only about one in 10 of these
are ever diagnosed; up to 10% bilateral
Most common:
? Horseshoe Kidney
? Unilateral renal agenesis
? Pelvic kidney
(Left kidney more likely to be abnormal)
Ectopic Kidney
? Function is general y normal initial y
? Abnormal position leads to obstruction in 50% of
ectopic kidneys
? Increased risk UTI, kidney stones, VUR
? Frequently associated with abnormalities of other
organ systems (uterine, cardiac, skeletal)
Ectopic Kidney Locations
Ectopic Kidney
(simple renal ectopia)
Mega ureter
? Ureters wider than 7 to 8 mm
? Normal ureteral diameter is rarely greater than 5 mm
? Primary MGU is 2-4 times more common in boys than girls
? Slight predilection (1.6 to 4.5 times) for the left side
? Bilateral in approximately 25% of patients
? In 10% to 15% of children contralateral kidney may be absent or
dysplastic
Three major classifications of megaureter based on primary and secondary causes
Pathophysiology
? Distal end of the ureter, as it becomes intramural and
subsequently submucosal, rearranges the muscular layers in its
wall.
? All layers become longitudinally oriented
? Ureteral adventitia fuses to the bladder trigone by attachment to
Waldeyer's sheath
? Sympathetic and parasympathetic innervation to the distal ureter
and UVJ area is believed to modulate primarily ureteral peristalsis
Diagnosis
Ultrasound
? Distinguishes MGU from UPJ obstruction based on the
presence or absence of a dilated ureter
VCUG
? to rule out reflux
Renal scintigraphy
? Provides objective, reproducible parameters of function
and obstruction
Whitaker's perfusion test & ureteral opening pressure
? To evaluate obstruction, but their invasiveness and
requirement for anaesthesia are drawbacks in children
Magnetic resonance urography
Magnetic resonance urogram showing obstruction at the right ureterovesical
junction
Management
Primary Refluxing Megaureter
? Medical management is often the initial approach
? Surgery
? Endoscopic subureteric injection, is recommended for
persistent high-grade reflux in older children
? Reconstructive surgery of a dilated ureter
? distal ureterostomy for unilateral reflux
? vesicostomy for bilateral disease
? Secondary Refluxing or Obstructive Megaureter
? Management of secondary MGUs is initially directed at their
root cause
? Primary "Dilated" Nonrefluxing Megaureter:
Nonobstructive versus Obstructive
? Expectant management is preferred
? Antibiotic suppression & radiologic surveillance is appropriate
in most cases
? Surgical correction
? Surgical Options
? Plication or infolding for moderately dilated ureter
Complications
Persistent reflux and obstruction
Postoperative VUR
Ectopic ureter
? Ureter whose orifice terminates anywhere other
than the normal trigonal position
? Lateral ectopia : an orifice more cranial and lateral
than normal
? Caudal ectopia : orifice is more medial and distal
than the normal position
? 80% are associated with a duplicated collecting system
? Females :
? More than 80% are duplicated
? Urethra and vestibule are the most common sites
? Males:
? most ectopic ureters drain single systems
? posterior urethra is the most common site
? Drainage into the genital tract involves the seminal vesicle
three times more often than the ejaculatory duct and vas
deferens combined
Ureterocele
(outpouching of ureter as it enters bladder)
This post was last modified on 08 April 2022