1. Hepatic Artery Thrombosis: Conservative Management or Retransplantation?
Professor Nigel Heaton
Kings Health Partners
Institute of Liver Studies
Kings College Hospital
London

2. Hepatic Artery Thrombosis: Conservative vs Retransplantion Topics to be covered
Arterial anatomy of the liver and biliary tree
Definition of early and late hepatic artery thrombosis
Incidence
Pathophysiology
Decision making and outcomes
:conservative management or retransplantation
Prevention? Personal data

3. Schematic of 3 & 9 o’clock arteries
38%
Arterial contributions to the bile duct
axial
distal supply dominant 2%
60%
Northover and Terblanche, BJS 1979

4. Early Hepatic Artery Thrombosis: Incidence
Definition not agreed – varying from 2 weeks to 3 months
Early HAT – within one month of transplant
Incidence: mean 3.9%, median 4.4%
Adults 2.9%, Children 8.3%
Era effect %
1993 – %
Higher incidence in lower volume centers (< 30 LTx) 5.8% vs 3.2%)
Bekker et al, AJT 2009; 9: 757

5. Late Hepatic Artery Thrombosis
One month to more than 3 months
Bekker et al, AJT 2009; 9: 757

6. Hepatic Artery Thrombosis: Pattern of injury - Early
Depends on the speed and efficiency of collateralisation
Bile duct ischemia
Infection
Cholangiolitic abscesses
Parenchymal necrosis
Liver failure and death
Personal data

7. Hepatic Artery Thrombosis: Pattern of injury - late
Non-anastomotic/complex biliary stricture
Cast formation on damaged biliary epithelium
Recurrent infection – cholangitis
Biliary abscesses and infarction
Malnourishment and ill health
Personal data

8. Hepatic Artery Thrombosis: Factors influencing collateralisation
Site of arterial thrombosis
Graft type? split / reduced grafts
Roux loop
Children vs adults
Multiple arteries
Timing after transplantation

9. Early Hepatic Artery Thrombosis: Mortality
Overall mortality 33% (0-80%)
Important cause of graft loss 53%
Mortality 33%
Clinical burden of retransplantation
Financial burden and escalating cost
Bekker et al, AJT 2009; 9: 757

10. Early Hepatic Artery Thrombosis Surgical Causes
Retrieval injury – tear, dissection, hematoma
Anastomotic stenosis
Kinking – short length of artery
Multiple arteries/arterial reconstruction
Use of arterial conduits
Pseudo-aneursym
Retransplantation

11. Early Hepatic Artery Thrombosis Non-Surgical Causes
Pro-coagulant states
JAK-2, Anticardiolipin antibody, Factor V Lieden
High hematocrit
Liver disease – PSC, HIV, FAP
Massive ascites
Drugs eg aprotinin, sirolimus?
Smoking

12. Early Hepatic Artery Thrombosis Non-Surgical Causes
Pediatric recipients - Small artery – neonatal liver graft
CMV negative recipient
Long cold ischemic time
Large graft
Small for size syndrome
ABO incompatibility

13. Early Hepatic Artery Thrombosis Presentation
Early asymptomatic
Presentation – unexplained fever
- bacteremia, septicemia
- liver dysfunction – transaminitis, cholestasis
- biliary leak/stricture
- Pseudo-aneurysm
Personal data

14. Early Hepatic Artery Thrombosis Evolution of ischemia
Asymptomatic – no ischemia on CT (collateralisation)
Patchy parenchymal ischemia
Extensive parenchymal necrosis
Cholangiolytic abscesses
Biliary leak
Personal data

15. Early Hepatic Artery Thrombosis Interventions
Revacularisation
Thrombectomy
Revision of vascular anastomosis
Thrombolytic drug therapy
Retransplantation
Conservative management
Combination of above

16. Early Hepatic Artery Thrombosis Intervention: Surgical Revascularisation
Revascularisation in 257 out of 510 cases from 47 studies
163 out of clear reporting of intervention and outcome
Revascularisation attempted in 75% adults and 54% of children
Overall success 56%
Correlation between early occurrence and successful revascularisation
Frequent (daily USS) associated with successful outcome - 66% vs 45%
Adults 61% vs 45% and children 92% vs 58%.
Retransplantation in 30% of attempted revascularisations
Bekker et al, AJT 2009; 9: 757

17. Early Hepatic Artery Thrombosis Intervention: Retransplantation
Revascularisation in 260 cases in 43 studies
Treatment of choice in 53%
Retransplantation in 50% of adults and 62% of children
Limited reporting of data
Mortality 50% (30-70%)
Outcome same for adults and children?
Bekker et al, AJT 2009; 9: 757

18. Hepatic Artery Thrombosis: Conservative Management or Retransplantation
Varying results of revascularization
Type of revascularization
Varying threshold for retransplantation between centers
Recipient and graft status at the time of revascularization
Time post hepatic artery thrombosis (extent of ischemia)

19. Hepatic Artery Stenosis Doppler Ultrasound Recognition
Tardus parvus waveform on Doppler ultrasound to identify stenosis
Low positive predictive value and high false positive rate
Tardus parvus defined as a waveform with a resistive index of < 0.5
and a systolic acceleration time of < 0.08 sec
Combined with optimal peak systolic velocity < / = 48cm/sec
Improved specificity to 99% and positive predictive rate of 88%
and false positive rate to 1% but decreasing sensitivity
Park et al, Radiology 2011; 260: 884

20. Endovascular treatment of recurring hepatic artery stenosis
941 LTx (5.1%) with HAS
6 patients underwent arterial and biliary surgical repair
5 retransplants for biliary stricture
37 treated with transluminal intervention
3 complications – dissection, haematoma
Outcome – HAS recurrence 9 (24%), HAT 4 (11%)
Repeat interventions -10 in 8 patients
Median follow up 66m with HA patency of 94.6%
5 year graft and patient survival of 82% and 87%
Sommacale et al. Transplant Int 2013; 26:

21. Proposed management – LFTs and CT angiography
Hepatic Artery Thrombosis: Conservative Management or Retransplantation
Proposed management – LFTs and CT angiography
Early recognition, normal transaminases, no graft ischemia on CT
urgent revascularization
Late recognition, transaminitis, parenchymal or biliary ischemia
Conservative management or retransplanatation
Significant or progressive ischemia
Liver retransplantation

22. Hepatic Artery Thrombosis: Prevention?
Microvascular techniques?
Immediate postoperative Doppler ultrasound
Daily ultrasound for first week (or ultrasound probe)
Management of hematocrit
Replacement of coagulation factors for ascitic loss
Use of heparin/aspirin prophylaxis
Parvus tardus – investigate with early intervention

23. Hepatic Artery Thrombosis: Conservative Management or Retransplantation: Summary
Early and late HAT: continue to be a challenge
Role for daily ultrasound for early recognition
CT angiography – key to management decisions
Role for early revascularisation
Morbidity and mortality associated with early retransplantation
Conservative management for late recognition with collateralisation