Renal/Liver transplants (test 3) Flashcards
What are the most commonly transplanted organs?
1=Kidney
2=Liver
What are common reasons for kidney transplants?
Treatment for patients with ESRD.
Improves longevity quality of life compared to dialysis.
What is the most common cause of ESRD?
Diabetes
What is the reason for liver transplants?
Treatment of acute or chronic liver failure.
6000 per year.
What are allograft renal transplants?
Living donors
Cadaver donors
Allograft=human tissue transplanted from one person to another
Where are renal transplants typically placed?
Right (preferred) or left iliac fossa.
Extraperitoneally.
What is a Carrel patch for cadaver transplants?
Main renal artery and surrounding patch of aortic wall are harvested.
Allows for larger anastomosis, may reduce RAS compared to living donor.
Cadaver transplants are anastomosed where?
end-to-side to external iliac artery.
What happens during a living donor transplant?
Main renal artery harvested.
End-to-side anastomosis to EIA or end-to -end anastomosis to IIA.
Harvested renal vein anastomosed to EIV with end-to end.
Renal transplant exam indications
Post-op
Suspected transplant dysfunction or complications.
RAS- htn, graft bruit, decreased renal function
Renal transplant risk factors?
Trauma from surgery. Renal vein thrombosis. Atherosclerosis in donor or recipient renal or iliac arteries. Acute tubular necrosis. Renal biopsy. Tortuous renal arteries
Renal transplant B-mode protocol
Done 24-48 hours post-op. Supine. Kidney length- long axis. Upper, mid, lower poles- trans Assess for fluid around kidney
Color and Doppler duplex protocol
Main renal artery: anastomosis, prox, mid, distal Main renal vein. Ipsilateral EIA and EIV (prox, mid, dist to anast). Intrarenal flow-upper, mid, lower poles
Renal transplant duplex protocol measurements
Measure: PSV EDV Acceleration time Acceleration index Resistive index. Transplant renal artery to iliac artery PSV ratio.
What is duplex used for in regards to renal transplants?
Evaluate possible causes of graft dysfunction.
Differentiate medically treated causes of graft failure, acute tubular necrosis, graft failure requiring intervention.
Normal duplex findings with renal transplants
Kidney appears similar to native.
Intrarenal and renal artery= low-resistance.
RI<0.70
Renal vein and iliac vein=phasic, continuous flow.
Iliac artery=monophasic or biphasic prox to anastomosis. triphasic distal to it.
What happens during renal allograft rejection?
Immune system attacks new kidney. No urine, decreased urine, swelling at site, increased blood urea nitrogen, hypertension. 3 types: hyperacute, acute, chronic. PSV may increase, EDV decrease. RI>0.8 Causes tubular and interstitial edema
What is the most common cause of graft loss?
Renal allograft rejection
What is hyperacute renal allograft rejection?
immediately post-op
What is acute renal allograft rejection?
About 2 weeks post-op, usually withing first 3 months.
What is acute tubular necrosis?
In surgery, a period of time with kidney has no perfusion and results in ATN.
Caused by ischemia.
More common in cadaver transplants.
Occurs early post-op~ day 2 or 3.
Other renal transplant complications
Perinephric fluid collection:
Hematomas, Urinomas, Lymphoceles
What are urinomas?
Collection of urine leaking from the ureteral anastomosis or focal area of ureteral necrosis.
Decreased urine output.
Located between kidney and bladder.
First few weeks post-op
What is suspected with acute pain in transplant area or anuria?
Arterial or venous thrombosis.
Considered medical emergency.
<1% occurrence.
Renal artery stenosis
Most common complication, 10% patients.
Severe uncontrolled HTN.
PSV>200-250, renal/EIA ratio >2.0-3.0, post-stenotic turbulence >50-60% RAS
Renal vein thrombosis
<4% patients.
Enalarged RV, no color or Doppler signal
Post-biopsy complications
Arteriovenous fistula-abnormal connection between artery and vein.
Pseudoaneurysm
Liver transplants overview
Acute or chronic live failure.
Unresponsive to medical treatment.
Indications for liver failure: Hep C, alcohol liver disease, Budd-Chiari syndrome, primary biliary cirrhosis.
What happens during a liver transplant?
Whole cadaver liver transplanted.
Placed in same place as original liver.
Possible to have partial living donor, often the right lobe is donated
Whole liver transplants
Variations in anatomy.
Donor bile duct to recipient common hepatic duct.
donor common hepatic artery to recipient hepatic artery.
IVC interposition or piggy-backed
Partial liver transplant
Right lobe common.
Include rt HV, rt PV, rt HA, rt Hep bile duct.
Oppositee included with left lobe transplanted.
Liver transplant complications
Graft falure/rejection. Bilary complications. Abnormal liver function tests. Ascites. Varices Sepsis.
Role of duplex for liver transplants?
Cannot diagnose rejection.
Can asses for fluid collections, vascular complications, bilary tree abnormalities
B-mode of liver transplant
Appearance.
Fluid may be present few days post-op.
Intraheptaic arteries (main, Rt, Lt)
PV (main, rt, lt)
Color and Doppler for liver transplants
Intrahepatic arteries.
PV.
IVC
Liver transplant duplex assessment
IVC patency.
HV patency.
PV for venous stenosis and flow direction.
Hepatic artery for stenosis.
Liver transplant complications
Hepatic artery thrombosis: most common, 2-12%
Hepatic artery stenosis: up to 11% patients. typically at anastomosis site, rare.
Portal vein thrombosis: signs of portal hypertension.
Portal vein stenosis: anastomosis site, PSV>125, velocity ratio 3:1
IVC stenosis/thrombosis.
