Editing Congenital urinary tract abnormalities (section)

== Kidneys ==

* Unilateral renal agenesis
** 1 in 500-1,000 births
** Results from failure of connection between the metanephric blastema and the ipsilateral ureteric bud
** Autosomal dominant trait with incomplete penetrance
** Typically, absent ipsilateral ureter
** Remaining kidney usually hypertrophic
** Ipsilateral testis and vas deferens/ovary and fallopian tube are usually absent, and sometimes adrenal gland
* Bilateral renal agenesis
** Incomplatible with life
* Multicystic disease
** Results from congenital severe renal dysplasia
** If bilateral, incompatible with life
** Mostly diagnosed on prenatal USS
** Previously excised, but nowadays treated conservatively - cystic kidney tends to regress
* Ectopic kidney
** Failure of kidney to ascend from the pelvis to its normal position
** Commonly, the renal pelvis also faces more anteriorly, as it starts off this way embryologically - the more ectopic the kidney, the more severe the rotational abnormality
** In most cases of ectopia, the kidneys are fused together
** In 'crossed renal ectopia', the kidneys are fused and are on the same side - one of the ureters crosses the midline to enter the bladder on the correct side
**
* Horseshoe kidney
** The two renal units are low-lying and the lower poles fuse to form an isthmus. Further ascent of the fused kidneys is prevented by the IMA.
** 1 in 1,000, with a 2:1 male predominance
** Unpredictable vascular supply
** Prone to reflux, obstruction and stone formation
**
* Duplex renal pelvis and ureter
** 1 in 150
** Mostly unilateral
** Left side more common
** Genetic basis
** Children with it often have VUR
** Generally asymptomatic when detected in adults
** Incomplete duplex - Y ureter
** Complete - a normal bud, which ends in the usual place, and a lower bud, which drains the lower pole of the kidney, and the lower bud often gets VUR
* Autosomal dominant polycystic kidney disease
** Multisystem disorder - liver, pancreas, arachnoid membrances
** Mutation in one of two different genes - PKD1 and PKD2, coding for proteins polycystin-1 and polycystin-2
** Does not usually manifest before 30yo
** Criteria:
*** At least 3 (unilateral or bilateral) renal cysts and 2 cysts in each kidney
** Differential
*** Autosomal recessive PKD
*** Tuberous sclerosis
*** Von Hippel Lindau
*** Renal cysts and diabetes syndrome
*** Orofaciodigital syndrome type 1
*** Medullary sponge kidney
*** Simple renal cysts
** Renal manifestations
*** Renal size - increases with age
*** Pain - dull loin ache - can get severe pain with haemorrhage into a cyst
*** Haematuria - 40% of patients with ADPKD get visible haematuria
*** UTI/cyst infection
*** Nephrolithiasis - 20% get it -  uric acid/calcium oxalate or both
*** HTN - most get it
*** ESKD - most patients maintain renal function within normal limits until 4th to 6th decade
** Extrarenal manifestations
*** Polycystic liver disease - usually asymptomatic, but can cause problems due to mass effect or cyst complications
*** Intra-cranial aneurysms - 10%
*** Valvular heart disease - mitral valve prolapse in 25%