Intravascular Ultrasound-Guided Catheter-Based Aspiration Thrombectomy in Patients With Acute Submassive Pulmonary Embolism: A Case Series.

Contrast pulmonary angiography by hand injection or power injection is widely used during catheter-based therapies for acute submassive and massive pulmonary embolism (PE). Particularly, in patients with pre-existing chronic kidney disease, this approach may present a prognostic challenge owing to a double-contrast load, initially during computed tomographic pulmonary angiography (CTPA), and during percutaneous treatment. Intravascular ultrasound (IVUS) has been used as an adjunctive imaging modality in the percutaneous treatment of chronic thromboembolic pulmonary hypertension, and in coronary and peripheral vascular interventions. We report a series of cases illustrating the use of IVUS in the management of acute PE. All five patients presented with an acute submassive PE with evidence of right ventricular (RV) strain (RV/LV ratio ≥ 0.90). Body mass index and B-type natriuretic peptide ranged from 18 to 47 kgm/m and 56-932 pg/mL (ref. ≤ 78), respectively. Three of the five patients had renal impairment prior to the procedure (acute kidney injury, AKI, and chronic kidney injury, CKD). Post-catheter-directed pulmonary embolectomy there was a modest reduction in mean pulmonary artery pressure in all five patients (range: -4 mmHg to -9 mmHg). The first case serves as a proof of concept of IVUS use in acute PE. This case series demonstrates that an IVUS-only approach in the catheter-directed management of acute submassive PE is feasible and may be of particular importance in patients with pre-existing renal dysfunction.