Authors: Manal Mirreh, MD AND Lea Matthews, MD - Children’s Hospital of Philadelphia
An 8-year-old girl with past medical history of HLHS previously palliated to extracardiac non-fenestrated Fontan presents for dynamic contrast MR lymphangiography with three-point lymphatic access (intranodal, intrahepatic, and intramesenteric). Which of the patient’s home medications should be held prior to the procedure?
EXPLANATION
Dynamic contrast magnetic resonance lymphangiography (DCMRL) is the gold standard for diagnosis of lymphatic insufficiency. DCMRL with multi-access lymphatic cannulation (intranodal, intrahepatic, and intramesenteric) involves percutaneous needle access to lymphatic vessels and, in some cases, transhepatic or transabdominal puncture. These routes carry a risk of bleeding, particularly through hepatic and mesenteric entry sites.1,2
Pediatric peri-procedural timing for low-molecular weight heparin (enoxaparin) is based on the pharmacokinetics (t½ approximately 4–6 hours) described in the American Society of Hematology 2018 guidelines for management of venous thromboembolism3 and the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines for Antithrombotic therapy in neonates and children4; in practice, pediatric congenital catheterization programs hold therapeutic enoxaparin for approximately 24 hours (equivalent to withholding 2 BID doses), with extended abstinence interval in patients with renal impairment. Potent antiplatelets such as clopidogrel should be held 5-7 days.5
Aspirin, when used as monotherapy, is typically continued because it presents minimal bleeding risk compared to the potentially serious thrombotic risk of stopping it—especially in patients with single-ventricle or shunt physiology. However, all medications should be managed on a case-by-case basis. Sildenafil should be administered as usual given the risk of rebound pulmonary hypertension when held.
REFERENCES
1. Dori Y, et al. Intrahepatic Dynamic Contrast MR Lymphangiography: Technique and Clinical Applications in Children With Lymphatic Flow Disorders. Radiology. 2016;281(3):816–825.
2. Itkin M, et al. Lymphatic Imaging and Interventions in Congenital Heart Disease. Circ Cardiovasc Imaging. 2021;14(5):e012348.
3. Witt DM, Nieuwlaat R, Clark NP, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: optimal management of anticoagulation therapy. Blood Adv. 2018;2(22):3257-3291. doi:10.1182/bloodadvances.2018024893
4. Monagle P, Chan AKC, Goldenberg NA, et al. Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e737S-e801S. doi:10.1378/chest.11-2308
5. Lau KK, Chan NK, Brophy JM, et al. Anticoagulation therapy in children: a practical guide. Paediatr Child Health. 2020;25(7):447-454.
