Created by Dr. Sharad Maheshwari • imagingsimplified@gmail.com • 22.12.2025

Radiology Education Series

Hepatic Artery Spasm
After Liver Transplant

Post–liver transplant imaging is a high-stakes game. A single wrong word can cost a graft. Confusing spasm with thrombosis is the most dangerous pitfall.

Thrombosis (HAT)

Surgical Emergency

• Flow-ending event
• Requires immediate intervention
• Irreversible graft damage if missed

Artery Spasm

Often Reversible

• Flow-limiting problem
• Resolves with conservative management
• Misdiagnosis leads to unnecessary risks

Physiology Before Pathology

Always ask: Is this a flow-ending problem or a flow-limiting problem?

Thrombosis Flow-Ending. The pipe is capped.

Spasm Flow-Limiting. The pipe is squeezed.

Lab Correlation: Biochemistry Clues

Spasm Profile

AST / ALT (LFTs) Mild Elevation

Bilirubin Normal / Stable

Synthetic Function Preserved

Thrombosis Profile

AST / ALT (LFTs) Massive Spike (>1000s)

Bilirubin Rising Early

Clinical Status Rapid Deterioration

*Normal bilirubin with mild LFT elevation suggests a perfusion issue (like spasm) rather than a complete cutoff.*

Doppler Ultrasound Findings

Resident Pitfall: Reduced diastolic flow ≠ Thrombosis. It usually means high resistance (spasm).

Feature	Spasm	Thrombosis
Systolic Flow	Present	Absent
Diastolic Flow	Reduced / Absent	Absent
Resistive Index	High (0.8–1.0)	1.0 (No flow)
Change over time	Dynamic	Fixed

CTA: The Golden Rule

The Golden Rule

If the hepatic artery fills only on a late arterial phase, it is NOT thrombosed.

Why Late Phase Matters

• Confirms arterial continuity
• Detects slow inflow states characteristic of spasm

Typical Spasm CTA Appearance

Smooth, tapered narrowing

Faint or delayed opacification

NO abrupt cut-off

Management Strategy

Treating Spasm

Medical (First Line)

Calcium channel blockers (e.g., Verapamil, Amlodipine), Nitrates, or Prostaglandins to relax arterial smooth muscle.

Interventional Radiology

Intra-arterial vasodilator infusion (e.g., Papaverine) directly into the hepatic artery for refractory cases.

Conservative

Watchful waiting with serial Dopplers if graft function is stable.

Treating Thrombosis

Surgery (Gold Standard)

Urgent thrombectomy and revision of the anastomosis. Essential for early HAT to save the graft.

Interventional Radiology

Catheter-directed thrombolysis or mechanical thrombectomy. RISK: High bleeding risk in early post-op period.

Re-Transplantation

Required if revascularization fails or if irreversible liver necrosis/biliary ischemia occurs.

Causes & Future Complications

Causes of Thrombosis

Surgical / Technical

Poor technique, size mismatch, kinking, intimal flap.

Hypercoagulability

Prolonged cold ischemia, small caliber arteries (pediatric).

Causes of Spasm

Mechanical Irritation

Clamp manipulation, suture handling, stretching.

Vasopressors & Stress

Noradrenaline, Vasopressin, Pain.
"BP is fine, Doppler looks bad."

HAT Complications

Biliary Ischemia (Critical)

Bile ducts depend 100% on arterial supply. Leads to ischemic cholangiopathy, strictures, bile leaks.

Graft Failure

Often requires urgent re-transplant.

Spasm Complications

Usually None

Most resolve with no long-term impact.

The Dangerous Sequence

Spasm → Stenosis → Thrombosis

Reporting: Save the Graft

AVOID

"Reduced arterial flow. Correlate clinically."

Vague and dangerous.

PREFER

"Delayed hepatic arterial opacification with preserved continuity and distal filling on late arterial phase, consistent with a low-flow state such as arterial spasm. No imaging evidence of complete arterial thrombosis at present."

Copied!

Knowledge Check

Q: A post-transplant patient has a Resistive Index (RI) of 0.95, reduced diastolic flow, and normal bilirubin. Diagnosis?

References

• Bhangoo A, Cheng S, Botchu R, et al. Imaging of Vascular Complications of Liver Transplantation. American Journal of Roentgenology (AJR). 2021. PMID: Available via PubMed
• Garcia-Criado A, Gilabert R, Salmeron JM, 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 Am J Roentgenol. 2003;181(3):831–838.
• Vit A, De Candia A, Bazzocchi M. Hemodynamic changes in the hepatic artery after liver transplantation: findings on color Doppler US. Abdominal Imaging. 2010.
• Propeck PA, Scanlan KA. Illustrative review of hepatic artery thrombosis in liver transplantation. RadioGraphics. 1998 (Updated online).

Radiology Education Series • Always correlate with clinical findings.