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CONGENITAL ANOMALIES OF UPPER URINARY TRACT

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CONGENITAL ANOMALIES OF UPPER URINARY TRACT Powered By Docstoc
					 CONGENITAL
ANOMALIES OF
UPPER URINARY
    TRACT
             INTRODUCTION
   Abnormalities of kidneys & ureters occur in 3 – 4 % of
    the new born infants
   Anomalies occur in number, shape & position
   Abnormalities can be detected by foetal ultrasound
   Congenital anomalies occur more frequently in kidney
    than in any other organ
   Significant incidence of renal anomalies are associated
    with congenital anomalies of other organs
      DEVELOPMENT OF KIDNEYS

   The urogenital system develops
    from intermediate mesoderm
    (extending along the dorsal body
    wall of the embryo.
   Urogenital ridge forms on each
    side of the dorsal Aorta.
   Nephrogenic cord is the part of
    urogenital ridge that gives rise to
    the urinary system.
   Genital/Gonadal ridge is the part
    of the urogenital ridge that give
    rise to genital system.
                          Contd.
   Urinary system begins to develop before genital system
   Urinary system consists of:
       Kidneys
       Ureters
       Urinary bladder
       Urethra
   Three slightly overlapping kidney systems are formed
    during intra uterine life, these are :
       Pronephros
       Mesonephros
       metanephros
                         METANEPHROS

   Permanent kidney develops
    from 2 sources
       Metanephric diverticulum or
        Ureteric bud
       Metanephric mass of
        intermediate mesoderm (
        metanephrogenic blastema)
   Ureteric bud is an outgrowth
    from the mesonephric duct
    near its entrance into the
    cloaca
                 METANEPHROS contd.

   Collecting ducts develop from the
    ureteric bud
   Bud penetrates metanephric tissue
    which is moulded over its distal
    end as a cup
   Bud dilates forming primitive
    renal pelvis
   Renal pelvis splits into cranial &
    caudal portions (future major
    calyces)
   Each major calyx forms 2 new
    buds
   These buds subdivide until 12 or
    more generations of tubules have
    formed
                       METANEPHROS contd.

   At the periphery more tubules
    form.
   Tubules of 2nd order enlarge &
    absorbs the 3rd & 4th generation
    forming minor calyces
   Collecting tubules of 5th &
    successive generations elongate &
    converge on minor calyx forming
    renal pyramid
   In short, ureteric bud forms:
        Ureter
        Renal pelvis
        Major & minor calyces
        Collecting tubules (1 – 3 million)
              ASCENT OF KIDNEY

   Originally a pelvic organ, kidneys later shift to higher
    position in the abdomen
   Caused by diminution of body curvature & by growth
    in lumbar & sacral regions
   In the pelvis, metanephros receives blood supply from
    pelvic branch of Aorta
   At abdominal level it is vascularised by arteries
    originating from Aorta at higher levels
   Lower vessels usually degenerate but some may remain.
RENAL ANOMALIES
   Anomalies of Number
   Anomalies of Ascent
   Anomalies of Form and Fusion
   Anomalies of Rotation
   Anomalies of Renal Vasculature
   Anomalies of Collecting System
   Anomalies of structure
     ANOMALIES OF NUMBER
   Bilateral renal agenesis

   Unilateral renal agenesis

   Supernumerary kidney
    ANOMALIES OF ASCENT
   Simple renal ectopia

   Cephalad renal ectopia

   Thoracic kidney
     ANOMALIES OF FORM AND
            FUSION
   Crossed renal ectopia with or without fusion

       Types
         Crossed renal ectopia with fusion
         Crossed renal ectopia without fusion

         Solitary crossed renal ectopia

         Bilaterally crossed renal ectopia
                      Contd.
   Forms of Crossed Renal Ectopia
     Inferior ectopic kidney
     Sigmoid or S-shaped kidney

     Lump kidney (Cake kidney)

     L – shaped kidney

     Disc kidney

     Superior ectopic kidney

     Horseshoe kidney
    ANOMALIES OF ROTATION
   Malrotated kidney
       Ventral position
       Ventromedial position
       Dorsal position
       Lateral position
        ANOMALIES OF RENAL
           VASCULATURE

   Aberrant, accessory or multiple vessels
   Renal artery aneurysm
   Renal arteriovenous fistula
    ANOMALIES OF COLLECTING
            SYSTEM
   CALYX & INFUNDIBULUM
       Calyceal diverticulum
       Hydrocalycosis
       Megacalycosis
       Extrarenal calyces
       Anomalous calyx
       Infundibulopelvic dysgenesis
   PELVIS
       Pelviureteric junction (PUJ) obstruction
       Extrarenal pelvis
       Bifid pelvis
ANOMALIES OF STRUCTURE
   Polycystic kidneys
     Autosomal recessive (infantile type)
     Autosomal dominant (adult type)

   Multicystic dysplastic kidney
   Simple renal cysts
   Medullary sponge kidney
URETERAL ANOMALIES
 Anomalies of termination
 Anomalies of structure

 Anomalies of number

 Anomalies of position
ANOMALIES OF TERMINATION
   Ectopic ureter
ANOAMLIES OF STRUCTURE
   Ureteral atresia
   Ureterocoele
   Ureteral stenosis and stricture
   Ureteral valves
   Ureteral diverticula
   Megaureter
    ANOMALIES OF NUMBER
   Duplication of ureter
     Incomplete
     complete
    ANOMALIES OF POSITION
   Retrocaval ureter
   Retroileal ureter
     SIMPLE RENAL ECTOPIA
   EMBRYOLOGY
       The ureter bud grows craniad towards the urogenital ridge
       The developing metanephric tissue & ureteral bud migrate
        caphalad, rotating medially on its long axis
   DESCRIPTION
       Pelvic kidney
       Lumbar kidney
       Abdominal kidney
   Ureteric orifice usually enters the bladder on the same
    side with normally situated orifice
    CROSSED RENAL ECTOPIA
    WITH OR WITHOUT FUSION
   Kidney is located on the side opposite from
    which its ureter inserts into a bladder
   Unilaterally fused kidney with inferior ectopia is
    the most common. It’s the superior pole of the
    ectopic kidney that usually joins with the inferior
    aspect of the normal kidney
    Types of Crossed Renal Ectopia
   Crossed renal ectopia with fusion
   Crossed renal ectopia without fusion
   Solitary crossed renal ectopia
   Bilaterally crossed renal ectopia
         HORSESHOE KIDNEY
   Most common of all renal fusion anomalies
   The joining occurs before the kidney have rotated on
    their long axis
   Mostly, the kidneys join at the lower pole by an isthmus
   The calyces are atypical, pointing posteriorly and axis of
    each pelvis remains in an oblique lateral plane
   The ureter inserts high on the renal pelvis and lie
    laterally
   60% of patients with horseshoe kidney remain
    asymptomatic for an average 10 yrs after discovery
    PELVIURETERIC JUNCTION
       (PUJ) OBSTRUCTION
   Most common cause of hydronephrosis in fetal kidney
   More common in boys with ratio of 5:2
   Typically due to intrinsic narrowing in which the
    ureteral segment has an interruption in the
    development of the circular musculature of the PUJ
   Or, an alteration in the collagen fibers in and around
    the muscular cells
   Or, an extrinsic narrowing seen in association with
    aberrant lower pole renal vessel passing anterior to the
    PUJ
           ECTOPIC URETER
   Any ureter whose orifice terminates anywhere
    other than the normal trigonal position
   Generally, ectopic ureteric orifice terminates
    either in urethra or outside the urinary tract
   TYPES
     Lateral ectopia
     Caudal ectopia
                          Contd.
   If the ureteric bud arises more proximally on the
    mesonephric duct than normally, the ureteric orifice has
    less time in the bladder to undergo its normal migration
    & results in a orifice more medial and caudal than is
    usual resulting in Caudal Ectopia
   If ureteric bud arises more distally, the orifice enters the
    bladder earlier than usual and migrate laterally and
    cranially resulting in Lateral Ectopia
   If ureteric bud arises still more proximally on the
    mesonephric duct, the ureteric orifice may remain on
    the mesonephric duct resulting in orifice termination
    outside the bladder
      MULTICYSTIC DYSPLASTIC
             KIDNEY
    Multicystic kidney of the newborn is usually unilateral,
    nonhereditary,and characterized by an irregularly
    lobulated mass of cysts
   The ureter is usually absent or atretic.
   It may develop because of faulty union of the nephron
    and the collecting system. At most, only a few
    embryonic glomeruli and tubules are observed.
   The only finding is the discovery of an irregular mass in
    the flank.
    DUPLICTION OF URETER
   Complete or incomplete duplication of the ureter is one
    of the most common congenital malformations of the
    urinary tract.

   Incomplete (Y) type of duplication is caused by
    branching of the ureteral bud before it reaches the
    metanephric blastema.

   In complete duplication of the ureter, the presence of 2
    ureteral buds leads to the formation of 2 totally separate
    ureters and 2 separate renal pelves.
                         Contd.
   Because the ureter to the upper segment arises from a
    cephalad position on the mesonephric duct, it remains
    attached to the mesonephric duct longer and
    consequently migrates farther, ending medial and
    inferior to the ureter draining the lower segment
    (Weigert-Meyer law).

   Thus, the ureter draining the upper segment may
    migrate too far caudally and become ectopic and
    obstructed, whereas the ureter draining the lower
    segment may end laterally and have a short intravesical
    tunnel that leads to vesicoureteral reflux
             URETEROCELE
   A ureterocele is a sacculation of the terminal
    portion of the ureter .
   It may be either intravesical or ectopic;
   Ectopic ureterocele is located at the bladder
    neck or in the urethra.
   Intravesical ureteroceles are associated most
    often with single ureters, whereas ectopic
    ureteroceles nearly always involve the upper pole
    of duplicated ureters.
                         Contd.
   Ureterocele has been attributed to delayed or
    incomplete canalization of the ureteral bud leading to
    an early prenatal obstruction and expansion of the
    ureteral bud prior to its absorption into the urogenital
    sinus
   The cystic dilation forms between the superficial and
    deep muscle layers of the trigone.
   There is nearly always significant
    hydroureteronephrosis, and a dysplastic segment of the
    upper pole of the kidney may be found in association
    with a ureterocele.

				
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