Deborah J. Rubens, MD 7/8/2015 Ultrasound of Liver … report • Vascular Anastamoses –HA –IVC...

Deborah J. Rubens, MDUltrasound of Liver Transplants

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Ultrasound of Liver Transplants

Deborah J. Rubens, M.D.Professor of Imaging Sciences, Oncology and Biomedical

Engineering University of Rochester Medical Center

Associate Director, Center for Biomedical UltrasoundUniversity of Rochester School of Medicine and Dentistry

DISCLOSURES

None

OBJECTIVES

• Understand normal transplant vasculature

• Distinguish abnormal Doppler parameters as predictors of transplant complications.

• Identify situations in which further imaging (ie. CT, MR, Angiography) may be useful to assess complications.

USA – Liver Transplantation 2009

• Total OLT: >6.5K • Pts on transplant waiting list: >16K• Newly registered pts: >11K www.seer.gov

Indications

• OLT – only treatment for irreversible acute liver failure and chronic end-stage liver disease (ESLD)

• Guideline for liver transplant candidacy - based on improved life expectancy with transplantation

• Priority - based on MELD score (bilirubin, creatinine, INR)

• OUTCOMES (Expected per SRTR)• Graft survival rates: 85%, 75% (1,3yr)

• Pt survival rates: 90%, 80% (1,3yr)

www.srtr.orgSRTR data 2010-2012.


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LI 4.1 Total adult liver transplants

OPTN/SRTR 2011 annual report

• Vascular Anastamoses– HA

– IVC

– PV

• Direct biliary anastomosis vs choledocho-jejunostomy

Liver Transplants: What are the key vascular connections?

NORMAL PIGGYBACK

ANASTOMOSISLIMITS IVC TO ONE

CONNECTION

Imaging Protocol

• Grayscale liver and spleen, biliary tree, perihepatic spaces

• Color and spectral Doppler– Hepatic arteries: main, right and left

– Portal vein: main, right and left

– Hepatic veins: right and middle and left

– Splenic vein

– IVC

Post- operative Liver Transplant

• Major complication Hepatic artery thrombosis or stenosis

• Less common portal vein, hepatic vein or IVC stenosis or thrombosis

HEPATIC ARTERYIMPORTANCE IN LIVER TXP

• Thrombosis or stenosis: 13%

• Leading cause of graft failure, from bile duct necrosis, infarction, abscess formation.*

• Dx in 10% of asx pts with aggressive screening early p/op **

• Rx: a. revision or re-txp References: *DeGaetano AM, Cotroneo AR, Maresca G, DiStasi C, Evangelisti R, Gui B, Agnes S. Journal of

Clinical Ultrasound, 28(8):373-80, 2000 October.**Sakamoto Y, Harihara Y, Nakatsuka T, Kawarasaki H, Takayama T, Kubota K, Kimura W, et al. The British Journal of Surgery, Volume 86(7), July 1999, pp. 886-889.


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HAS/HAT Disastrous Complication

DX OF HA THROMBOSIS/STENOSIS• Resistive index (RI) <.5

and/or acc time > .08sec inany of vessels (M, R or L)– 73-81% sensitivity for HA

T/HAS*, **

• False Positives: – Small non-vis HA’s p/op – Reperfusion injury with

shunting (high velocitiy/ normal acc time).

• False negatives: – Rapid collateral formation.***

*Dodd GD, Memel DS, Zajko AB, Baron RL, Santaguida LA. Radiology 1994 192: 657-661.**Platt JF, Yutzy GG, Bude RO, Ellis JH, Rubin JM. AJR 1997;168:473-476.

***Wolf R, Porte RJ, van der Vliet TM, Kok T. Journal of Clinical Ultrasound, 29(7):406-10, 2001 Sept.

Rising LFT’s Post–op Txp

Day 1-Normal HA

Day 3-Wall thump in HA

Abnormal LFT’s –HAS?

HAT with collateral flow seen on US Corresponding PTC shows

biliary necrosis

False Positive: Intraparenchymal Shunting

Post Operative Day 0 Post Operative Day 1

Low RI’s- HAS? Adult LRD Right Lobe AllograftHAT with Normal RIs

Saad WEA, Lin E, Ormanoski M, Darcy MD, Rubens DJ. Noninvasive Imaging of Liver Transplant Complications .Tech Vasc Interventional Rad 10:191-206, 2007.

HA (arrowheads) reconstituted from phrenic artery collaterals (arrows)


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Spectral Doppler and RI’s First Ten Days Post Op

Normal 37.8% (244/645)

RI = 1 32.6% (210/645)

RI < 0.5 16.7% (108/645)

Absent HA 12.8% (83/645)

Hedegard , Bhatt, Saad, Rubens, Dogra Hepatic arterial waveforms on early posttransplant Doppler ultrasound. Ultrasound Q. 2011 Mar;27(1):49-54

Do High RI’s predict HAT?

Initial study on 10/1 with high RI and normal liver.

Study 11/25 with no hepatic artery and abnormal liver.

Garcia-Criado, et al: Significance of and contributing factors for a high resistive index on Doppler sonography of the hepatic artery immediately after surgery: prognostic implications for liver transplant recipients; AJR: 181(3): 831-8, Sept. 2003.

Spectral Waveforms of 56 Patients with HAT Days 0-10

Nonvisualization of HA26/83 (31.3%)

Low RI < 0.5 9/108 (8.3%)

RI = 1 10/210 (4.8%)

Normal hepatic waveforms 11/244 (4.5%)


ABSENT DIASTOLIC FLOW-USUALLY RETURNS TO NORMAL

NO INCREASED INCIDENCE OF HAT

Day 1

Day 3

Hedegard , Bhatt, Saad, Rubens, Dogra Nonvisualization of Hepatic Arteries on Post-transplant Doppler Ultrasound: Technical Limitation or Real?-RSNA 2008

Day 1

Day 14

Management of Non-vis HA:Rescan, CEUS, Angiography or OR?

Transient NonvisualizationRescan <24 hours All HA’s present

4/52 (7.6%) HAT

Persistant NonvisualizationOne or more HA

22/31 (71.0%) HAT

Odds Ratio 30.00 (95% CI 8.15 to 105.65)


IMPROVED HA VISUALIZATION WITH US CONTRAST

• 8/72 no flow on CDUS • 6 flow on CEUS

(Optison .5ml)– confirmed with angio or

nl f/u US.• 2 no flow, angiography

confirmed• US sensitivity rose from

.91 to 1.0 (p<.014)Benjamin K. Hom, BS, Ruchi Shrestha, MD, Suzanne L. Palmer, MD, Michael D. Katz, MD, R. Rick Selby, MD, Zhanna Asatryan, BA, Jabali K. Wells, BS and Edward G. Grant, MD Prospective Evaluation of Vascular Complications after Liver Transplantation: Comparison of Conventional and Microbubble Contrast-enhanced US Radiology 2006;241:267-274


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HAS?

Mha anastomotic stenosis balloon angioplasty

6 WEEKS POST ANGIOPLASTY

SELECTIVE HA ARTERIOGRAM STENT PLACED

ONE MONTH LATER

ONE MONTH LATER

SIX MONTHS LATER


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IVC AND HEPATIC VENOUS OUTFLOW OBSTRUCTION

• Rare in cadaveric transplants (1.3%) due to direct IVC-IVC anastomosis (1)

• Increased (6.7-16.6%) in live donors; small hepatic veins anastomoses (2)

• Presentation: abd pain, ascites, poor liver fx • Doppler dx: monophasic waveform (1,2)

• 10mm pressure gradient across stenosis considered clinically significant (2,3)

(1) Rossi et al. Upper IVC Anastomotic Stenosis in Liver Transplant Recipients: Doppler US Diganosis: Radiology 1993;187:387-389.

(2) Ko et al. Hepatic Vein Stenosis after Living Donor Liver Transplantation: Evaluation with Doppler US Radiology 2003; 229: 806-810

(3) Ko et al. Endovascular Treatment of Hepatic Venous Outflow Obstruction after Living-donor Liver Transplantation JVIR 2002; 13: 591-599

IVC Thrombosis and Stenosis

POST TRANSPLANT COMPLICATIONS IVC POST TRANSPLANT COMPLICATIONS: HEPATIC VEINS

RHV dampened waveform on 2 separate scans, however no relevant clinical symptoms so no revision needed.

Symptomatic HV StenosisElevated Hepatic Wedge Pressures

Required IVC Revision

Note 4:1 ratio of HV velocity at narrowed area vs proximal intrahepatic velocity.

IVC STENOSIS RELATED DONOR

Leg and abdomen swelling 3 years post txp . Treated over 15 months with multiple trials of angioplasty, eventually successfully stented.


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PORTAL VEIN COMPLICATIONS

• Stenosis-common- usually asymptomatic. • Thrombosis, relatively rare. • HA-PV fistulae-common

– post traumatic, (liver biopsy) – Doppler : low RI in feeding h a, arterialized

shunt flow in enlarged pv– require embolization for sx (cardiac failure)

PORTAL VEIN THROMBOSIS POST LIVER TRANSPLANT INITIAL EXAMS NORMAL

3 mo later

Rapidly deteriorating liver fx, required retransplantation

Redundant portal vein predisposed to PV thrombosis.

Day1

Day 2Day 3 post thrombectomy

Portal Vein Stenosis

• Usually at anastomosis

• Angiographically stenosis = 8mm gradient

• Stenotic velocity155 cm/sec (nl= 58cm/sec)*

• 3:1 ratio yields 73% sensitivity for stenosis*

• Many resolve spontaneously over time

– (Grant et al 2009 RSNA)

*Chong, WK, Beland, JC, Weeks SM: Sonographic Evaluation of Venous Obstruction in Liver Transplants AJR, June 1, 2007; 188(6): W515 - W521

PORTAL VEIN STENOSIS?

Patient asymptomatic and ratio normal, so no rx.

PV Stenosis?

3 months later


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PORTAL VEIN STENOSIS

Peak PV Vel >155 and ratio of 5:1

Post Transplant Hepatic CT

Post Stent PORTAL VEIN THROMBOSIS?

No detectable flow in the MPV with reversed flow in R and LPVs? Doesn’t make sense. What to do? Get a CT.

HEMATOMA COMPRESSES MPV

FOLLOWING DECOMPRESSION


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RHA TO PORTAL VEIN FISTULA

54 yr old man, 2 yrs post liver transplant with abnormal liver function.

RPV

RIGHT HA-PV FISTULA

HA- PV Fistula

• Common Complication

• Most Asymptomatic

• Seen in up to 50% of patients within 1 week post biopsy

• Less than 10% persist beyond a week

• Most close spontaneously


HA Pseudoaneurysms

• Extrahepatic

• Occur at anastomosis

• Often missed at US

• US 13% sensitivity

• CTA 78%


Arterial Steal Syndromes

• ?Consequence of excess PV flow

• Dx by arteriography-low flow into allograft

• US shows elevated RI’s with low velocity or loss of HA flow signal, loss of diastolic flow most specific

• Angiography demonstrates increased flow to the splenic a. or gastroduodenal a.

• Rx includes splenic artery embolization

Garcia-Criado AJR 2009;193(1):128–135Sanyal and Shah JUM 2009:28:471-477


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Post Coiling

24 hours later

Immediate

PV Steal

• Residual varices divert inflow from PV

• Cases C/O Mindy Horrow

Poor portal vein flow post-operativelyPatient returned to OR

Day 1

Day 2

Despite revising anastomosis, intraoperative flow is very poor

Large splenorenal varices shunted flow from PVLigation of varix improved PV flow

Pre-operative imagingHorrow, etal. JUM 2010;29:125

5 months post transplant-

Portal Vein Thrombosis

Acute thrombus

large coronary varices

Embolization of varices and thrombectomy of portal vein re-establishes flow


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Conclusions

• Doppler US central to management of hepatic transplants

• Critical for diagnosis of arterial and venous thromboses and stenoses as well as abnormal flow patterns

• Identifies post interventional sequelae including arteriovenous fistulae and pseudoaneurysms.

THANK YOU

Deborah J. Rubens, MD 7/8/2015 Ultrasound of Liver … report • Vascular Anastamoses –HA –IVC...

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