Liver Transplants (Ch. 20)

OPTN (Organ Procurement and Transplantation Network) states that 1 donor can save up to __ lives

8

indications for liver transplant (MC and 2nd MC?)

• severe liver disease

• drugs

• hepatitis C, B, and autoimmune hepatitis

• cirrhosis (MC reason)

• ETOH (2nd MC reason)

• hepatocellular carcinoma

• sclerosing cholangitis

• hemochromatosis

• Wilson’s disease

• nonalcoholic steatohepatitis

• Budd Chiari syndrome

• biliary syndrome

• biliary disease

  • biliary atresia

  • alagille syndrome

  • primary sclerosing cholangitis

liver disease symptoms

• jaundice

• fatigue

• weight loss

• ascites

• black stool

• itching

• bleeding in stomach

• confusion

• nausea

• loss of appetite

?? delete hepatic encephalopathy causes…

• confusion from liver disease

• disorientation

• altered mental status

• minimally responsive

contraindications

• severe irreversible illness

• widespread cancer

• HIV/AIDS

• active/uncontrolled infection

• severe pulmonary HTN

• active ETOH/substance abuse

• poor social support

MELD and PELD

• MELD (Model for End-Stage Liver Disease) and PELD (Pediatric End-Stage Liver Disease) are scoring systems

  • prioritize patients on liver transplant waiting list

• predicts likelihood of waitlist mortality (death without a transplant within the next 3 months)

who performed the very first liver transplant? and when?

Dr. Thomas Starzl on March 1, 1963

• first 5 transplant recipients died within 23 days

• 1967: first successful liver transplant performed by Dr. Starzl

  • pt. survived 1 year due to recurrent HCC

• 1989: first living donor liver transplant performed

cadaveric liver transplant procedure (pt. 1)

• liver can be preserved between 8-12 hours on ice

• donors and recipients are rechecked to verify a match

  • tissue and blood match

• “mercedes sign” (across chest)

  • diseased liver is detached from its surrounding structures, and the major blood vessels are clamped and ligated

• vessel alterations

  • anastomosed or trimmed down to size

  • if donor vessel is too short, an iliac artery or iliac vein graft may be used to extend it

    • iliac vein graft: conduit b/w recipient SMV and donor PV

    • iliac artery graft: conduit b/w recipient infrarenal AO and donor HA

anastomosis increases risk of what?

stenosis

why is a conduit used in B and C?

the donors’ vessel was too short to anastomosis to the receipts’

cadaveric liver transplant procedure (pt. 2)

• donor IVC and recipient IVC are connected using a “piggyback” technique

  • donor IVC sewn end to side or within the recipient IVC)

  • (ANNOTATE: “IVC/IVC anast”)

• end to end portal anastomosis

• end to end common hepatic artery anastomosis

• CBD is anastomosed

• cholecystectomy is done on donor liver

  • sonographer should image the fossa (follow main lobar fissure—from MPV to the GB neck)

• surgical drains may be placed in right and left subhepatic spaces and secured to the skin with sutures

a living donor liver regenerates to more than ___% of its original volume

85

living donor liver transplant procedures

• RLL donated to a recipient; will vary (surgical report)

• “mercedes sign,” vessels clamped and ligated

• vessel alterations

  • anastomosed or trimmed down to size

  • iliac vein graft: conduit b/w recipient SMV and donor PV

  • iliac artery graft: conduit b/w recipient infrarenal AO and donor HA

living donor liver transplant procedure

• end to end HV and IVC anastomosis

• end to end PV anastomosis

• end to end HA anastomosis

• end to end duct anastomosis

• drains placed posterior to liver and inferior to incision

US evaluation of liver transplant

• smooth, homogeneous, and moderately echogenic

• usually performed immediately post-operatively, day 1, 3, and 5, 7

  • document date of transplant (body can reject transplant in 10 days)

• know the type of liver transplanted!!

  • refer to surgical report and/or previous images

• assess size, echogenicity, contour, biliary tree, and vasculature

  • biliary stents may be present

• any masses, fluid collections, or ascites present?

PW Doppler evaluation of liver transplant

• evaluate for thrombus or stenosis

• waveforms should fill the spectral window

• PVs

• HAs

• HVs

• IVC/IVC anastomosis (deceased donor)

• HV/IVC anastomosis (living donor)

• velocity should never double.trimple at various locations

• if stenosis detected, PW Doppler at and after narrowing (highest velocity)

transplant portal veins

• hepatopedal (red)

• continuous flow with minimal respiratory changes

• <125 cm/s for PV transplant

  • normal PV velocity is 20-30 cm/s in native liver

• above the baseline flow

• Doppler at, above, and below the anastomosis

what does the red star represent? blue circle? yellow star?

• red star: post PV anastomosis

• blue circle: at PV anastomosis

  • site of anastomosis (hues of color)

• yellow star: pre PV anastomosis

**velocity should not be double or triple anywhere

transplant hepatic arteries

• resistive index of transplant HA:

  • normal RI (documented for each HA): between 0.50-0.70

  • abnormal RI: 0.80—could indicate rejection, but 0.80 is normal immediately post-op b/c of edema

  • low RI indicative of proximal stenosis

  • high RI indicative of rejection or hepatic venous congestion

• rapid upstroke with continuous diastolic flow above the baseline

• velocity less than 200 cm/sec

• low resistive waveform—with high diastolic component

is this normal or abnormal RI for transplant HA?

normal

transplant hepatic veins

• hepatofugal (blue)

• phasic bidirectional flow—indicated by “to-fro” sign

  • LHV more pulsatile due to proximity to heart (common)

transplant IVC/IVC anastomosis

• identified by aliasing

• phasic and bidirectional flow

• donor/txp IVC is always closer to the liver

what is this showing?

infrahepatic anastomosis (below HV)

what is this showing?

postoperative imaging

• flow is IMPORTANT!!

• edema

  • can cause little to no diastolic flow and inc. RIs

• fluid collections and hematomas are common

  • sequential evaluations to document dec. in size

  • within the first 2 weeks

what does increase of fluid collection post-op indicate?

active bleeding; therefore, look at previous images to ensure measurement is accurate

what is this showing? (3 options)

1. fluid collection

2. hematoma (if solid components within)

3. abscess (gas/dirty shadowing; reverberation artifact)

• with abscess, pay attention to HAs—check if its patient because they’re correlated

liver transplant pathology: rejection

• acute, within first 10 days of transplantation

• chronic, develops over time and causes fibrosis

• S/S:

  • RUQ pain

  • fever

  • tachycardia

  • hepatomegaly

  • ascites

  • elevated LFTs

  • encephalopathy

liver transplant pathology: infection and abscesses

• thick walls

• poorly defined borders

• complex

• gas bubbles

liver transplant pathology: HV and IVC thrombosis and stenosis

• no Doppler flow

• stent placement

what is this showing?

what is this showing?

liver transplant pathology: PV thrombus and stenosis

• fresh/new thrombus appear echogenic; old thrombus appears anechoic

• if thrombus has no Doppler flow, it is occlusive

  • occluded PV → cavernous transformation

• stent placement

liver transplant pathology: hepatic artery stenosis

• aliasing and turbulent flow

• RI less than 0.50

• velocity >200 cm/s

• tardus parvus waveform

  • present distally to stenosis (very slow upstroke to peak)

what is this CT showing?

HA stenosis—stenotic region is very thin

what do you see?

other liver transplant pathology (pt. 1)

• HA thrombosis

  • MC vascular complication of liver transplant

  • leads to biliary ischemia

  • absence of color and no flow on spectral Doppler

• HA pseudoaneurysm

• biliary complications

  • obstruction from stricture at the anastomosis or from ductal stone

• fluid collections

  • seromas (near perihepatic space and near vascular and biliary anastomoses sites)

  • lymphoceles, bile leaks, and bilomas

  • ascites (resolved within 7-10 days)

what is this showing?

HA thrombosis..

what should sonographer do to prove HA thrombosis

• turn up PW gain to see noise

• should confirm no flow to prove HA thrombosis

what is this showing? (in HA)

HA pseudoaneurysm

what is this showing?

biloma

• bile leak

• round

• complex

• in GB fossa

other liver transplant pathology (pt. 2)

• hepatocellular carcinoma metastatic disease

  • recurrence of HCC seen in 40% of cases

• hepatitis C recurrence

  • reinfection occurs in nearly all patients

  • 20% develop cirrhosis within 5 years of transplantation

  • controversial

• PV gas and bowel ischemia

  • if PV gas seen beyond post-op state=poor prognosis

  • high mortality rate of 75-90%

  • SONO:

    • echogenic foci flowing through the vein (gas within vascular system) on grayscale or entire liver parenchyma (severe cases)
      

what is this showing?

portal venous gas

**emergency is air bubbles are mobile

liver transplant pathology: posttransplant lymphoproliferative disorder (PTLD)

• most severe complications found in solid organ and stem cell transplantation

• caused by chronic use of immunosuppressant medication

• masses caused from Epstein-Barr virus (EBV)

liver transplant pathology: benign findings

• cysts

• hemangiomas

• pneumobilia

• fatty liver and focal sparing

what is this showing?

posttransplant lymphoproliferative disorder (PTLD)

• hypoechoic area on CT

what do you see?

AV fistula

• may be from biopsy

• aliasing—arterial and venous waveform shown

  • difficult to distinguish

• mosaic waveform

• velocity >200 cm/s

what do you see?

• tardus parvus arterial and venous waveform

  • Doppler all around

  • cine

• AV fistula

normal vs abnormal HA RI waveform?

• normal: 0.5-0.70

  • brisk upstroke

  • slow end diastolic component

• abnormal: >0.80

PV RI waveform

• continuous forward flow

• minimal respiratory alterations

HV RI waveform

• to-fro flow

would this be from a living or deceased donor?

deceased donor

**write “IVC to IVC anast”

liver can be preserved for how many hours on ice?

8-12 hours

what is the “mercedes” sign?

• scar left from liver transplant

  • from bilateral subcostal skin incisions that extend to the midline up to xiphoid process