Percutaneous Mechanical Thrombectomy With the Inari ClotTriever Device in a Pediatric Population

Purpose: Pediatric deep vein thrombosis (DVT) is rare, resulting in significant morbidity caused by postthrombotic syndrome (PTS). Catheter-directed therapy (CDT) and percutaneous mechanical thrombectomy (PMT) can decrease PTS severity in iliofemoral DVT and have been described in the pediatric population, usually reserved for limb-threatening cases. Inari ClotTriever (Inari Medical) is a large-bore PMT device described for DVT removal in adults. We describe its use in a pediatric population.

Materials and Methods: We reviewed the cases of three patients who underwent ClotTriever PMT at our pediatric hospital in 2020 and 2021. Iliofemoral DVT was diagnosed using ultrasonography and magnetic resonance venography or computed tomography venography, which showed no extrinsic compression.

Results: Case 1: A 17-year-old female patient on oral contraceptive pills (OCPs) with left leg pain was found to have left iliofemoral DVT. The patient failed to improve after 5 days of systemic anticoagulation. After unsuccessful overnight CDT and rheolytic PMT, the patient was treated with ClotTriever device and overnight CDT, with clot resolution on final venographym. No acute bleeding complications occurred. The patient was discharged on apixaban (Eliquis). On 3-month follow-up, the patient had improved symptoms and imaging demonstrating patent left lower extremity veins. Case 2: An 11-year-old female patient on OCPs with right leg pain was found to have right iliofemoral DVT. The patient failed to improve after 4 days of systemic anticoagulation and thrombolysis. After unsuccessful rheolytic PMT, the patient was treated with ClotTriever device, with clot resolution on final venogram. No acute bleeding complications occurred. The patient was discharged on apixaban (Eliquis). The patient had symptom resolution on 6-month follow-up. Case 3: A 15-year-old female patient with polycystic ovary syndrome on OCPs with right leg pain and dyspnea was found to have right iliofemoral DVT and segmental pulmonary embolism. The patient was started on systemic anticoagulation overnight and treated with single-session ClotTriever PMT with an embolic protection device, with resolution of clot burden on final venography. No acute bleeding complications occurred. The patient was discharged on subcutaneous enoxaparin (Lovenox) after improvement in symptoms, with plans for follow-up.

Conclusions: We describe the safety and feasibility for large-bore PMT with Inari ClotTriever in the pediatric population for acute iliofemoral DVT. Further investigation into its safety and efficacy should be explored in the pediatric population.