Our evolution in the treatment of hepatic artery and portal vein thrombosis in pediatric liver transplantation: Success with catheter-directed therapies.

BACKGROUND: In pediatric liver transplant recipients, hepatic artery thrombosis and portal vein thrombosis are major causes of acute graft failure and mortality within 30 days of transplantation. There is, however, a strong possibility of graft salvage if flow can be re-established to reduce ischemic injury. The current standard treatment is surgical revascularization, and if unsuccessful, retransplantation. Due to our success in treating these complications with catheter-directed therapies, we sought to summarize and publish the outcomes of all patients who experienced hepatic artery thrombosis or portal vein thrombosis within 30 days of liver transplantation. METHODS: We conducted a retrospective cohort analysis of 27 pediatric liver transplant recipients who experienced hepatic artery thrombosis (n = 13), portal vein thrombosis (n = 9), or both (n = 5) between September 2012 and March 2021. We collected and tabulated data on the patients and therapies performed to treat them, including success rates, primary and secondary patency, and clinical outcomes. RESULTS: Among these patients, 6 were managed with anticoagulation and relisting for transplant and 21 had a primary revascularization attempt. Surgical recanalization was attempted in 7 patients of which 3 had successful recanalization (43%) and catheter-directed recanalization was attempted in 14 patients with 100% success in re-establishing blood flow to the graft. Additionally, patency was increased, and mortality was decreased in patients treated with catheter-directed recanalization compared to surgical revascularization or anticoagulation alone. CONCLUSION: This data illustrates the need to further investigate catheter-directed thrombolysis as a potential first-line treatment for postoperative HAT and PVT in pediatric liver transplant recipients.

Doppler ultrasound for post-angioplasty follow-up in pediatric segmental branch renal artery stenosis: A case report.

INTRODUCTION: Segmental branch renal artery stenosis is an important cause of renovascular hypertension in the pediatric population that is often managed with angioplasty and may require imaging multiple times pre- and post-procedure. Gold standard imaging is angiography, which exposes children to radiation and intravenous contrast. There is not a clear guideline for imaging during follow-up, but patients are monitored for symptom recurrence, which could then trigger repeat imaging. The following case highlights a method of follow-up that has not been broadly studied that may offer benefits over clinical monitoring alone, and how interprofessional cooperation could offer effective surveillance and reassurance for families through a cost-effective method that minimizes potential for harm. CASE AND OUTCOMES: This report describes the clinical course of a child with hypertension secondary to segmental branch renal artery stenosis who was treated with angioplasty and who received follow-up imaging with renal Doppler ultrasound. This method allows the care team to ensure stability of the caliber of the repaired vessel and non-recurrence of stenosis at follow-ups through monitoring for intra-arterial velocity and waveform changes. DISCUSSION: Close follow-up of children with renal artery stenosis is vital following intervention due to high risk of recurrence. Clinical follow-up alone could be sufficient for some patients, however many still require CTA, sometimes even more than once, when symptoms worsen or there is evidence of end-organ damage. During follow-up, collaboration with skilled sonographers to monitor post-repair velocities and waveforms using Doppler ultrasound presents several possible advantages. This includes providing reassurance to patient families, minimizing harmful radiation and contrast exposure, and the potential for early detection of recurrence of stenosis. Especially in cooperative, older pediatric patients with a normal BMI who have a main renal artery stenosis or even in those with a segmental branch stenosis identified through CTA such as in this case. CONCLUSION: This case demonstrates how coordination with sonographers and the use of ultrasound with Doppler could improve the follow-up of pediatric patients with segmental branch renal artery stenosis post-angioplasty to provide further reassurance to families, minimize harm to patients, and ensure post-procedure stability beyond just clinical parameters.

Management of Acute Portal Vein Thrombosis With Serial Mechanical Thrombectomy and tPA in a Pediatric Liver Transplant Recipient: A Case Report.

BACKGROUND: Acute portal vein thrombosis is a major cause of fulminant allograft failure in pediatric liver transplantation. Timely intervention is critical to save the graft and patient. Serial interventional radiologic management of this condition is scarcely reported in the literature. CASE SUMMARY: A recently transplanted 17-year-old male presented to the emergency department with abdominal pain. Rising liver enzymes prompted discovery of a diffuse portal thrombus, which precipitated fulminant liver failure. The adolescent developed respiratory failure, vasodilatory shock, acute kidney injury, and hepatic encephalopathy, complicating treatment. Multiple interventions attempted to clear the thrombus, including interventional radiologic and medical therapies. Uniquely, a continuous infusion catheter was placed at the thrombosis, delivering local tissue plasminogen activator during a 5-day period. Upon thrombus clearance, the patient made a full recovery with no complications during 12 months of follow-up. CONCLUSIONS: When used as a component of multidisciplinary management, continuous locally directed tissue plasminogen activator may be a useful tool for clearance of persistent portal vein thrombosis.