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Developmental and positional anomalies of the kidneys - Coggle Diagram
Developmental and positional anomalies of the kidneys
RENAL EMBRYOLOGY
Pronephros
No adult funcion
Induces mesonephros
Differentiate into
MESONEPHRIC DUCT
Wolffian system
:male_sign:
Seminal vesicles
Vas deferens
Epididymis
Efferent ductules
:female_sign:
Remnants in girls
Ureteric bud
Metanephric blastema bud
Collecting system of ureter
Renal Pelvis
Calyx
Collecting tubules
Bowman's Capsule
Convoluted tubules
Loop of Henle
RENAL DISPLASIAS AND HYPOPLASIAS
Ureter implantation
Normal trigonal implantation
A, E, F
Normal renal parenchyma
Cranial location
B C D
Caudal location
G H
Dysplastic kidneys
Increased risk VUR
Hypoplastic kidney
Normal
Decreased number of nephrons
Oligomeganephronic type
Decreased number of nephrons
Hypertrophy of the ones present
Ask-Upmark kidney
Reflux nephropathy
Small kidney c segmental hypoplasia
Secondary to ascending pyelonephritis
VUR
Hypertension
Epidemiology
:female_sign: 2:1 :male_sign:
Unilateral dz--> Nephrectomy
Bilateral dz --> Medically
Polyuria
Failure to concentrate urine
No hypertension
RENAL AGENESIS
Abnormal induction of metaneprhic blastema
Involution of multicystic dysplastic kidney
Epidemiology
1:1000
:female_sign: 2:1 :male_sign:
Unilateral renal agenesis --
Hypertrophy of the contralateral kidney
L Kidney affected unilateral renal agenesis.
Renal function is normal
Bilateral renal agenesis
1:4800
:male_sign: 3:1 :female_sign:
Presentation
Oligohydramnios
Pulmonary hypoplasia
Potter's facies (Low set ears, broad flat nose, a prominent skin fold beginning over the eye and running to the check)
Renal arteries and ureters absent
Underdeveloped bladder
Presence of absence of ureter is helpful suggesting the cause of renal agenesis
Absence of hemitrigone
Failure of ureteral bud to form properly
Normal trigone
Evidence of a ureter leading to a nubbin
Involution of Multicystic dysplastic kidney
Diagnostic studies
VCUG
Clinical presentation
:female_sign:
30% abnormality of the Müllerian duct to the Mayer-Rokitansky Sx.
(Müllerian, uterine, or upper vaginal duplications or without obstruction
Vaginal Agenesis
Older presentation
Hydrocolpos
Lower abdominal pain after menarche
:male_sign:
Abnormal vas during hernia repair
SUPERNUMERARY KIDNEY
Additional kidney
Own blood supply and parenchyma
Caudal to the normal kidney
Usually smaller
Cranial location
Ureter separate & enters bladder ectopically
Separate ureteral bud inducing metanephric blastema and migrating very low on mesonephric duct
Diagnosis
Stones 50%
Hydronephrosis
Abnormal induction of metanephric blastema by an abnormally directed ureteric bud.
Separate ureteral bud from mesonephric duct
Part of a Y duplication
RENAL ECTOPIA
Failure of rotation-- Kidney with renal pelvis anteriorly directed
Hyper-rotation Renal pelvis can point posteriorly
Renal vessels normal
Renal pelvis and calyces appear abnormal on IV urogram due to unusual orientation
Contralateral kidney rotational abnormality or ectopia
Renal scan
Radionucleotide in bladder can overlay a pelvic kidney-- Foley during the study
Pelvic kidney is located more anteriorly than orthotopic kidneys
Function may be artifically lowered by the distance of the kidney from the camera.
Epidemiology
1:1000
:male_sign: 3:2 :female_sign:
Thoracic Kidney
Ectopic abdominal kidney
Above iliac crest
Lumbar kidney
Anterior to the iliac vessels at sacral promontory
Pelvic kidney
Below aortic bifurcation & opposite the sacrum
Subdiaphragmatic
Not associated c true congenital hernia
Diagnosis
Asymptomatic
Prenatal US
Risks
UPJ
VUR
Stone formation
Anatomy
Can include extrarenal pelvis and infundibulum
High insertion of ureter into pelvis
MIMICS UPJ obstruction
Repair
Side to side ureteropyelostomy or
ureterocalycostomy to a dilated lower pole calyx
HORSESHOE KIDNEY
Anatomy
Lower than normal
Lower poles fuse in the midline and drape anteriorly over the spine.
Kidneys "hurdle" the iliac vessels during ascent, they come into contact at the lower pole and fuse.
Kidney can't ascend past the IMA
Epidemiology
1:400
:female_sign: 2:1 :male_sign:
Associated with:
Sacral agenesis
HIgh cloacas
Turner syndrome (45, XO gonadal dysgenesis)
Vague abdominal pain
10% Ureteral duplication
50% VUR
33% UPJ
Repair of UPJ obstruction in a horseshoe kidney
Treatment
Kidney stones
Extracorporeal shock wave lithotripsy
Ureteroscopy
Percutaneous Nephrolithotomy
CROSS FUSED RENAL ECTOPIA
Lower pole of one kidney crossed the midline to fuse with orthotopically placed contralateral kidney.
Left crosses the midline
Ureters instert in the normal position in the bladder
Association:
Multicystic dysplasia
Obstruction
VUR
AR Polycystic Kidney disease
1:40:000 LIve births
Die soon after birth
Bilaterally enlarged -- small cysts radially oriented throughout parenchyma
Cysts are DILATED COLLECTING TUBULES
Portal hepatic fibrosis-- Portal hypertension
Hepatic involvement appears inversely proportional to renal involvement.
Severe prenatal form
(>90% renal involvement)
Death by 6 wks from pulmonary hypoplasia
Neonatal form
(60% renal involvement)
Lethal by 1 year
Infantile form
(25% renal involvement)
Hepatosplenomegaly
Survival up to 15 years
Juvenile form
<10% renal involvment
Severe periportal fibrosis
Survival up to 15 years
Portal hypertension usually lethal s liver txpx
PKDH1 gene
Prenatal US
Bilaterally enlarged echogenic kidneys
Sunburst pattern
US
Treatment
Dialysis
Nephrectomy to make space for PD
Renal transplant... usually don't require liver txpx
ARPKD
Parent will
NOT
have cysts
AD PKD
1:500 patients
3rd-5th decade of life
Cysts few and scattered
Diagnosis
US
15-39 y/o
Three or more unilateral or bilateral cysts
ADPKD
Parent will have cysts
ARPKD
Parent will
NOT
have cysts
Pregnancy
Higher risk of Preeclampsia
Hypertension
Renal insufficiency
UTI
Presentation
:
Pain
Hematuria
HYPERTENSION
Renal Failure (extensive bilateral cysts)
Neonates (Renal enlargement)
Associated findings
Hepatic involvement biliary cysts
Cysts in the spleen
Pancreas
Lungs
Mitral valve prolapse
Colon diverticuli
Berry aneurysms of the circle of Willis
PKD1
PKD 2
MULTICYSTIC DYSPLASTIC KIDNEY
Pathophysiology
Severe uretral obstruction
Failure in ureteric bud-metanephric blastema induction
RX
Peripheral cysts surround a dominant central cyst mimicking the renal pelvis "hydronephrotic form" of MCDK
Cysts randomly distributed throughout the kidney s dominant medial cyst or evidence of communication
DDx
Severe hydronephrosis bc UPJ obstruction
Most common renal cystic mass in the newborn
R/o
VCUG
Contralateral kidney 30% of time
only c association
Follow-up:
+Usually involute
US c 6mo for the 1st 2 yrs. life
US at 5 &10 yrs if non-operative approach
Closer follow up, pt c:
Hydronephrosis
UTI
Atrophic kidney
Treatment
OP
Medical
Classification
CYSTIC NEPHROMA
Tumor of cysts
Overall round configuration
Lined with epithelium and septae that contain tubules
Benign end of spectrum progessing from cystic Wilms tumor
Cystic partially differentiated nephroblastoma to cystic nephroma
Risk of sarcomatous degeneration
:male_sign: 2:1 :female_sign:
Women over 30
Rarely bilateral
Tx.
Partial nephrectomy
Shelling out tumor by following plane of pseudocapsule
CYSTIC PARTIALLY DIFFERENTIATED NEPHROBLASTOMA
:male_sign: younger than 2yo.
:female_sign: 3-4th decade
Herniation of parenchymal mass into renal pelvis
Well circumscribed
Rx identical to cystic nephroma only dx HISTOLOGICALLY
Blastema is found in the septations
Stage I
Limited to capsule
Fully resected tumors
Stage II
Outside renal capsule but fully resected
Tx Vincristine
Dactinomycin
Doxorubicin
Presentation:
Asymptomatic flank mass
Occasionally hematuria
Treatment
Partial nephrectomy
SIMPLE CYSTS AND CALYCEAL DIVERTICULI
Simple renal cyst:
US
Distinct wall
No internal echoes
Posterior enhancement
Bosniak classification
Treatment
Percutaneous
Laparoscopic
Ureteroscopic ablation
Perc puncture c (Alcohol, bismuth, povidone-iodine)
Lap decort may shift threshold for tx. of large asymptomatic simple cysts
Bx.
Only if cyst characteristics are other than for a simple cyst.
Symptomatic due to UPJ or
infundibulum obstruction
Bosniak Classification description
D. Dx
Benign condition causing a complex cyst
Calyceal diverticulum or hydrocalyx both communicate c colecting system.
Fluid enhances on IVP or CT
Treat when stones are found or infection.
