Early Hepatic Arterial Thrombosis After Pediatric Living Donor Liver Transplantation: A Single-Center Experience

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Early Hepatic Arterial Thrombosis After Pediatric Living Donor Liver Transplantation: A Single-Center Experience

Pediatric living donor liver transplantation (pLDLT) is a critical intervention for children with end-stage liver disease, but it carries significant risks, including early hepatic arterial thrombosis (eHAT), a life-threatening complication. This article synthesizes a single-center study of 278 pLDLT cases performed between January 2015 and January 2019, focusing on the incidence, management, and outcomes of eHAT, alongside strategies to mitigate its occurrence.

Incidence and Clinical Characteristics

Among 278 pLDLT recipients, three cases (1.08%) developed eHAT, diagnosed on postoperative days 2, 4, and 9. The primary indication for transplantation in 67.6% of cases was decompensated cirrhosis due to biliary atresia, followed by congenital metabolic diseases (29.1%) and acute liver failure (3.2%). The three patients with eHAT included two females and one male, aged 6–8 months, weighing 6–7 kg. Graft weight-to-recipient weight ratios (GWRW) were 4.0%, 2.8%, and 4.2%. Two patients had undergone prior diagnostic bile duct exploration. All grafts were left lateral lobes, and biliary reconstruction involved Roux-en-Y hepaticojejunostomy.

Diagnosis and Immediate Management

eHAT was detected via Doppler ultrasonography (DUS) in all cases, with confirmation by contrast-enhanced ultrasonography in one patient. The median time to diagnosis was postoperative day 5. Two patients underwent immediate thrombectomy and arterial reanastomosis, resulting in restored hepatic arterial flow. Postoperative surveillance revealed transient hepatic hypoechoic foci and elevated transaminases in one patient, resolving spontaneously. Both survivors remained complication-free during follow-up periods of 2 and 4 years. The third patient, diagnosed on day 9, succumbed to cardiac insufficiency on day 16 despite normal liver function preceding death.

Risk Factor Analysis

Although no statistically significant risk factors were identified, the study highlighted several considerations:

  1. Graft Size Matching: A GWRW threshold of 5% was emphasized, with monosegment grafts preferred when GWRW exceeds 5% or the anteroposterior graft-to-abdominal cavity ratio exceeds 1.5. Oversized grafts risk abdominal compartment syndrome, vascular compression, and thrombosis.
  2. Microsurgical Techniques: Arterial anastomosis was performed by experienced surgeons using a 120° three-point interrupted suture technique to ensure intimal integrity. Loupes (2.5–5× magnification) were deemed sufficient for vessels 1–3 mm in diameter, avoiding microscopes to reduce operative time.
  3. Complex Arterial Anatomy: In cases of multibranched hepatic arteries (e.g., middle hepatic artery origin from the right hepatic artery or separate origins of S2–S4 arteries), multiple anastomoses were prioritized to enhance biliary perfusion, despite technical challenges. Interposition grafts, such as the right gastroepiploic artery (REGA) or great saphenous vein, were utilized for size-mismatched vessels.
  4. ABO Incompatibility: Eight patients underwent ABO-incompatible transplantation without vascular complications, attributed to meticulous perioperative management and immunosuppression.

Immunosuppression and Anticoagulation Protocols

The standard regimen combined steroids with calcineurin inhibitors (tacrolimus or cyclosporine), initiated 36 hours postoperatively. Mycophenolate mofetil was added for children under 3 years or ABO-incompatible recipients. Basiliximab, an interleukin-2 receptor antagonist, was administered intraoperatively and on day 4 for patients >25 kg.
Anticoagulation included intravenous heparin (10 IU/kg/h) transitioning to oral warfarin, tailored to individual risk profiles. Early warfarin discontinuation (before 3 months) was considered for stable patients to minimize bleeding risks.

Surgical and Postoperative Surveillance Strategies

  1. Intraoperative Measures: Routine Doppler ultrasonography ensured anastomotic patency before abdominal closure.
  2. Postoperative Monitoring: DUS was performed twice daily during the first week and once daily in the second week. This protocol enabled early detection of eHAT, which typically occurs within the first 7–10 days.
  3. Revascularization Over Retransplantation: Immediate thrombectomy and reanastomosis were prioritized, achieving success in 67% of cases. Retransplantation, while life-saving, was avoided due to graft shortages. Endovascular thrombolysis was contraindicated due to bleeding risks.

Long-Term Outcomes and Comparative Data

The 1.08% eHAT incidence in this cohort reflects advancements in microsurgical techniques and graft selection, contrasting with historical rates of 3.8% reported between 1993–2006. A 2017 study of 440 pLDLT cases reported no HAT, underscoring the impact of evolving practices. Key institutional strategies included strict GWRW limits, preferential monosegment grafts, and standardized anticoagulation.

Conclusion

Early diagnosis via vigilant DUS surveillance, prompt surgical intervention, and optimized graft-recipient matching are pivotal in reducing eHAT-related morbidity and mortality. The study advocates for surgeon-led arterial anastomosis, judicious anticoagulation, and tailored immunosuppression to mitigate risks. While retransplantation remains a last resort, refining preventive measures and thrombectomy techniques can substantially improve outcomes in pediatric LDLT.

Available at: http://doi.org/10.1097/CM9.0000000000001250

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