Deborah J. Rubens, MD Ultrasound of Liver Transplants 7/8/2015. Indications DISCLOSURES. Ultrasound of Liver Transplants OBJECTIVES

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1 Ultrasound of Liver Transplants None DISCLOSURES Deborah J. Rubens, M.D. Professor of Imaging Sciences, Oncology and Biomedical Engineering University of Rochester Medical Center Associate Director, Center for Biomedical Ultrasound University of Rochester School of Medicine and Dentistry 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 Indications Total OLT: >6.5K Pts on transplant waiting list: >16K Newly registered pts: >11K 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) SRTR data

2 LI 4.1 Total adult liver transplants OPTN/SRTR 2011 annual report Liver Transplants: What are the key vascular connections? Vascular Anastamoses HA IVC PV Direct biliary anastomosis vs choledochojejunostomy NORMAL PIGGYBACK ANASTOMOSIS LIMITS 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 ARTERY IMPORTANCE 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

3 HAS/HAT Disastrous Complication DX OF HA THROMBOSIS/STENOSIS Resistive index (RI) <.5 and/or acc time >.08sec in any 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 : **Platt JF, Yutzy GG, Bude RO, Ellis JH, Rubin JM. AJR 1997;168: ***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 Abnormal LFT s HAS? Day 1- Normal HA Day 3-Wall thump in HA HAT with collateral flow seen on US Corresponding PTC shows biliary necrosis Low RI s- HAS? False Positive: Intraparenchymal Shunting Adult LRD Right Lobe Allograft HAT with Normal RIs Post Operative Day 0 Post Operative Day 1 Saad WEA, Lin E, Ormanoski M, Darcy MD, Rubens DJ. Noninvasive Imaging of Liver Transplant Complications.Tech Vasc Interventional Rad 10: , HA (arrowheads) reconstituted from phrenic artery collaterals (arrows) 3

4 Spectral Doppler and RI s First Ten Days Post Op Normal 37.8% (244/645) RI = % (210/645) RI < % (108/645) Absent HA 12.8% (83/645) Initial study on 10/1 with high RI and normal liver. Do High RI s predict HAT? Study 11/25 with no hepatic artery and abnormal liver. Hedegard, Bhatt, Saad, Rubens, Dogra Hepatic arterial waveforms on early posttransplant Doppler ultrasound. Ultrasound Q Mar;27(1):49-54 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 Spectral Waveforms of 56 Patients with HAT Days 0-10 Nonvisualization of HA 26/83 (31.3%) ABSENT DIASTOLIC FLOW- USUALLY RETURNS TO NORMAL NO INCREASED INCIDENCE OF HAT Day 1 Day 1 Low RI < 0.5 9/108 (8.3%) RI = 1 10/210 (4.8%) Normal hepatic waveforms 11/244 (4.5%) Day 3 Day 14 Hedegard, Bhatt, Saad, Rubens, Dogra Hepatic arterial waveforms on early posttransplant Doppler ultrasound. Ultrasound Q Mar;27(1):49-54 Hedegard, Bhatt, Saad, Rubens, Dogra Nonvisualization of Hepatic Arteries on Post-transplant Doppler Ultrasound: Technical Limitation or Real?-RSNA 2008 Management of Non-vis HA: Rescan, CEUS, Angiography or OR? Transient Nonvisualization Rescan <24 hours All HA s present Persistant Nonvisualization One or more HA 4/52 (7.6%) HAT 22/31 (71.0%) HAT Odds Ratio (95% CI 8.15 to ) Hedegard, Bhatt, Saad, Rubens, Dogra Hepatic arterial waveforms on early posttransplant Doppler ultrasound. Ultrasound Q Mar;27(1):49-54 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:

5 HAS? 6 WEEKS POST ANGIOPLASTY Mha anastomotic stenosis balloon angioplasty SELECTIVE HA ARTERIOGRAM STENT PLACED ONE MONTH LATER ONE MONTH LATER SIX MONTHS LATER 5

6 IVC AND HEPATIC VENOUS OUTFLOW OBSTRUCTION Rare in cadaveric transplants (1.3%) due to direct IVC-IVC anastomosis (1) Increased ( %) 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) IVC Thrombosis and Stenosis (1) Rossi et al. Upper IVC Anastomotic Stenosis in Liver Transplant Recipients: Doppler US Diganosis: Radiology 1993;187: (2) Ko et al. Hepatic Vein Stenosis after Living Donor Liver Transplantation: Evaluation with Doppler US Radiology 2003; 229: (3) Ko et al. Endovascular Treatment of Hepatic Venous Outflow Obstruction after Living-donor Liver Transplantation JVIR 2002; 13: 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 Stenosis Elevated Hepatic Wedge Pressures Required IVC Revision IVC STENOSIS RELATED DONOR Note 4:1 ratio of HV velocity at narrowed area vs proximal intrahepatic velocity. Leg and abdomen swelling 3 years post txp. Treated over 15 months with multiple trials of angioplasty, eventually successfully stented. 6

7 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. Portal Vein Stenosis Day1 Day 2 Day 3 post thrombectomy 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? PV Stenosis? Patient asymptomatic and ratio normal, so no rx. 3 months later 7

8 PORTAL VEIN STENOSIS Post Transplant Hepatic CT Peak PV Vel >155 and ratio of 5:1 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 8

9 RHA TO PORTAL VEIN FISTULA RIGHT HA-PV FISTULA RPV 54 yr old man, 2 yrs post liver transplant with abnormal liver function. 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% Saad WEA, Lin E, Ormanoski M, Darcy MD, Rubens DJ. Noninvasive Imaging of Liver Transplant Complications.Tech Vasc Interventional Rad 10: , Saad WEA, Lin E, Ormanoski M, Darcy MD, Rubens DJ. Noninvasive Imaging of Liver Transplant Complications.Tech Vasc Interventional Rad 10: , 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): Sanyal and Shah JUM 2009:28:

10 Post Coiling PV Steal Residual varices divert inflow from PV Cases C/O Mindy Horrow Immediate 24 hours later Poor portal vein flow post-operatively Patient returned to OR Day 1 Despite revising anastomosis, intraoperative flow is very poor Large splenorenal varices shunted flow from PV Ligation of varix improved PV flow Day 2 Horrow, etal. JUM 2010;29:125 Pre-operative imaging 5 months post transplant- Portal Vein Thrombosis large coronary varices Embolization of varices and thrombectomy of portal vein re-establishes flow Acute thrombus 10

11 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 11