Hepatic Artery Thrombosis: Conservative Management or Retransplantation?

Professor Nigel HeatonProfessor Nigel Heaton

Kings Health PartnersKings Health PartnersInstitute of Liver StudiesInstitute of Liver Studies

Kings College HospitalKings College Hospital

LondonLondon

Hepatic Artery Thrombosis: Conservative vs RetransplantionTopics 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

Schematic of 3 & 9 o’clock arteries

Northover and Terblanche, BJS 1979

38%

60%

2%

Arterial contributions to the bile duct

axial

distal supply dominant

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 1982-1996 6.9%

1993 – 2006 3.8%

Higher incidence in lower volume centers (< 30 LTx) 5.8% vs 3.2%)

Bekker et al, AJT 2009; 9: 757

Late Hepatic Artery Thrombosis

One month to more than 3 months

Bekker et al, AJT 2009; 9: 757

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

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

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

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

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

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

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

Early Hepatic Artery Thrombosis Presentation

Early asymptomatic

Presentation – unexplained fever

- bacteremia, septicemia

- liver dysfunction – transaminitis, cholestasis

- biliary leak/stricture

- Pseudo-aneurysm

Personal data

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

Early Hepatic Artery Thrombosis Interventions

Revacularisation

Thrombectomy

Revision of vascular anastomosis

Thrombolytic drug therapy

Retransplantation

Conservative management

Combination of above

Early Hepatic Artery Thrombosis Intervention: Surgical Revascularisation

Revascularisation in 257 out of 510 cases from 47 studies

163 out of 315 - 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

Early Hepatic Artery ThrombosisIntervention: 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

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)

Hepatic Artery StenosisDoppler 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

Endovascular treatment of recurring hepatic artery stenosis

941 LTx 1998-2010 48 (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: 608-615

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

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

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