Urology Flashcards
Where are the kidneys located anatomically? What are the kidneys surrounded by?
The kidneys lie in the retroperineum on the psoas and quadratus lumborus muscles; they are encased by Gerota fascia (so are the adrenals)
What are the embryologic components of the kidney? What structures do these components form?
Pronephros (4th week): primitive kidney
Mesonephros (4-5th weeks): ureters, pelvis, calyces, and collecting system
Metanephros (5th week): glomeruli and PCT thru DCT
What is different about the course of the left and right renal ARTERIES?
The right renal artery passes behind the IVC whereas the left renal artery enters directly from the aorta
What is the branching pattern of the renal arteries?
Renal artery, 5 segmental branches, interlobar, arcuate, interlobular, afferent, glomerular capillaries, efferent, vasa recta capillary system
What is the difference between the left and right renal veins?
The right renal vein drains straight into the IV; the left renal vein courses anterior to the aorta and then drains into the IVC
Which veins drain into the left renal vein during its longer course?
The left gonadal, the left adrenal, and the lumbar veins
What are three embryologic abnormalities that can occur with the kidneys?
Pelvic kidney: cannot pass the umbilical arteries
Horseshoe kidney: catch the IMA
Renal agenesis: bilateral is incompatible with life (potter syndrome)
How much of the cardiac output goes to the kidneys? How much of the renal plasma flow is filtered? What is the equation for eRPF? GFR?
EASY 20% and 20%
Remember: eRPF = UxV/Px ((urine concentration x urine flow rate)/plasma concentration) with PAH as the substrate; GFR is the same equation but with Cr instead
Which 4 organs play a role in the RAA system?
Liver: produces angiotensinogen
Kidneys (JGA): produces Renin
Lungs: produces ACE
Adrenal gland: synthesizes Aldosterone
What are the five most common causes of hematuria in pediatric patients? Adult patients?
Pediatrics: UTI, Glomerulonephritis, Congenital urinary tract abnormality, urolithiasis, or trauma
Adults: UTI, Glomerulonephritis, bladder cancer, urolithiasis, or BPH
What can help distinguish between a renal cause of hematuria and a post-renal cause?
RED BLOOD CELL CASTS
What the S/Sx’s of ADPKD? What are 2 complications that can occur with ADPKD?
S/Sx’s include: HTN, flank pain, hematuria, or proteinuria
Complications: chronic renal failure, berry aneurysms
What percentage of patients with ADPKD develop berry aneurysms? What percentage of CRF patients have ADPKD?
10-30%
10%
Which disease should come to mind when presented with enlarged kidneys on exam or imaging studies?
ADPKD or ARPKD
Which organs are affected in a child with ARPKD? What are the likely causes of death in these patients?
Kidneys and liver both have multiple cysts
COD: renal failure or liver fibrosis
Which etiologies should be considered with a false positive urine dipstick for blood? Which substrates can appear to cause gross hematuria but yield a false urine dipstick for blood?
Myoglobinuria
Anthocyanin from beers and berries, rifampin, porphyria, pyridine
What is the classic triad of symptoms for RCC? What percentage of patients will present with this triad? What other symptoms may be present?
Triad: flank pain, palpable mass, hematuria seen in 10-15% of patients
Other symptoms: fatigue, weight loss, cachexia, or signs of a paraneoplastic syndrome
What types of paraneoplastic syndromes can be seen in RCC?
Cushings (ACTH), polycythemia Vera (EPO), hypercalcemia (PTHrp), galatorrhea (prolactin)
How is RCC diagnosed? How is the definitive diagnosis made?
CT or MRI; do not use a percutaneous biopsy (too many false negatives + chance of seeding the tract); confirmation is made after surgical excision
What role does ultrasound play in the diagnosis of RCC?
It can help distinguish between a solid and cystic lesion
What is the standard of treatment for a kidney tumor? When is this not the case?
Radical nephrectomy (standard): Remember definitive diagnosis is only made after removal
Partial nephrectomy if solitary kidney, bilateral tumors, or VHL disease
What are 3 complications of a partial nephrectomy for the treatment of RCC?
Urinary fistula (requires stent and/or catheter), IVC invasion by tumor cells, 10% chance of recurrence
How does RCC spread?
Lympatically and hematogenously (renal vein and IVC classically invaded)
What is the follow up for a patient with surgical removal of RCC?
CT scan (abdomen/pelvis), CXR, urinalysis, and LFTs every 6 months
What is the 5 year survival for patients with different stages if RCC?
Stage 1: >97% (confined to local parenchyma)
Stage 2: 74-96% (confined within Gerota fascia)
Stage 3: 40-70% (lymph node or vein involved)
Stage 4: <36% (distant metastasis)
What percentage of kidney tumors are RCC? What percentage of visceral cancers are RCC? Why is this important clinically?
85%
3%
This is the rationale for radical nephrectomy!
Who is at risk for RCC? Urolithiasis? Incidence and recurrence rate of urolithiasis?
RCC: males (2:1) in their 50s and 60s
Urolithiasis: males (3:1); 1 in 100-500 (average risk of approximately 1%); recurrence is 36% within 1 year and 50% within their lifetime
What are the different types of stones and their relative probability? Which stones are radiolucent?
Calcium oxalate/phosphate: 75
Struvite: 10-15
Uric acid: 10-15
Cystine: <1
Uric acid and Indinivir stones