Chapter 129 - Renovascular disease acute occlusive and ischemic events Flashcards
Renal ischemic injury mechanism
Glomerular collapse + tubular necrosis –> reduced glomerular filtration –> loss of tubular function
Reperfusion renal injury
Endothelial dysfunction –> excess cytokine secretion –> leukocyte influx
Excessive NO and ROS –> parenchymal damage
1 hour warm ischemia associated with this much renal function loss
how much recovery is expected?
70-80%
Complete recovery within weeks
2 hours warm ischemia time how much recovery is expected
30-50%
Collaterals of the renal artery
1) inferior adrenal
2) gonadal
3) ureteral
4) internal iliac
5) lumbar
6) intercostal
7) capsular arteries
8) IMA
Prevalence of assessory/aberrant or duplicate renal arteries
24-42%
Symptoms of acute renal ischemia
1) abdominal/back pain
2) dyspnea
3) nausea vomiting
4) hematuria
5) anuria
6) acute HTN
Differential diagnosis to acute renal ischemia
1) pyelonephritis
2) renal carcinoma
3) mesenteric ischemia
4) cholecystitis
5) biliary colic
6) gastritis
7) splenic infarction
8) myocardial infarction
9) pulmonary embolism
Classic triad of renal vein thrombosis
1) flank mass
2) gross hematuria
3) thrombocytopenia
only in 13% of neonates with renal vein thrombosis
Lab findings of acute renal ischemia
1) leukocytosis
2) elevated LDH
3) microscopic/gross hematuria
4) proteinuria
5) elevated D-dimer
6) eosinophilia (atheroembolism)
does normal Cr rule out renal ischemia
no, contralateral kidney may still function well
CTA sensitivity for renal ischemia
80%
CTA sen and spe for renal vein thrombosis
100%; 100%
CTA finding on renal infarct
1) hypoattenuation with associated mass effect
2) cortical rim sign - rim of functioning nephrons from capsular collaterals
US in renal artery ischemia
Only useful in detecting total occlusions
Otherwise poor sensitivity
Nuclear scan in renal ischemia
97% sensitivity
Sign: Marked reduction of renal blood flow with preserved kidney size
Renal artery embolism incidence in hospital
0.007%
Risk factors of cholesterol crystal embolization
1) male
2) HTN
3) atherosclerosis
4) following arterial cath
Cholesterol crystal embolization to kidney and association with dialysis in 2 years
30%
Percentage of patients with renal artery embolism with previous thromboembolism
20%
Outcome of renal artery embolization
11% death 1 month
61% return to normal
8% dialysis
Mortality following surgical renal artery thrombectomy
25%
Causes of renal artery thrombosis
1) atherosclerosis
2) aortic occlusion
3) aortic/renal dissection
4) renal aneurysm
5) FMD
6) Takayasu
7) stent thrombosis
8) hypercoagulable state
9) trauma
10) antiphospholipid antibody
11) factor V Leiden
12) HITT
13) Bechet
Prevalence of renal artery atherosclerotic stenosis
7%
5 year rate of thrombosis in pre-existing renal artery stenosis
5%
Risk factors for progression to renal artery thrombosis
1) SBP > 160
2) DM
3) > 60% stenosis
Factors associated with risks of spontaneous renal artery dissection
1) FMD
2) Ehlers-Danlos
3) cocaine use
4) strenuous exercise
Success of endovascular treatment of renal artery thrombosis
70% technically successful
25% recover renal function
Mortality after open surgical revasc for renal thrombosis
salveage of renal function
15-25% mortality
65% salvage
Mortality after renal artery trauma
21%
usually due to associated injuries
10.3% mortality without other major organ injuries
Kidney salvage rate in unilateral traumatic renal artery injury
25%
Grade IV/V kidney injury predictors of poor outcome
1) blunt trauma
2) dialysis or Cr > 200
3) <25% remaining renal function of affected kidney
4) postinjury HTN
Causes of renal vein thrombosis
1) malignancy (RCC, lymphoma, retroperitoneal tumor) 66%
2) nephrotic syndrome 20%
3) inherited thrombophilia
4) local surgery/inflammation
5) oral contraceptive use
6) pregnancy
7) infection
8) iatrogenic (IVC filter)
Risk factors that precipitate renal vein thrombosis
1) CVC
2) dehydration
3) prolonged hypotension
Risk of recurrent renal vein thrombosis
1%/year
Mortality 6 months after acute renal vein thrombosis
40%
largely due to malignancy and infection
Survival advantage treatment for renal vein thrombosis
Warfarin therapy
Indication for thrombectomy/thrombolysis in renal vein thrombosis
1) failure of oral anticoagulation (propagation, PE)
2) bilateral thrombosis
3) thrombosis of solitary kidney
4) caval thrombosis
5) acute renal failure
6) persistence of symptoms (flank pain)
