Faculty Bibliography

While pulmonary embolism (PE) causes approximately 100 000-180 000 deaths per year in the United States, mortality is restricted to patients who have massive or submassive PEs. This state of the art review familiarizes the reader with these categories of PE. The review discusses the following topics: pathophysiology, clinical presentation, rationale for stratification, imaging, massive PE management and outcomes, submassive PE management and outcomes, and future directions. It summarizes the most up-to-date literature on imaging, systemic thrombolysis, surgical embolectomy, and catheter-directed therapy for submassive and massive PE and gives representative examples that reflect modern practice. (c) RSNA, 2017.

There has been a resurgence of interest in defining the optimal treatment for severe pulmonary embolism (PE), fueled by pivotal and provocative trials, new catheter-based medical devices, and growing evidence of deleterious short- and long-term outcomes. In this environment, and especially given the multidisciplinary nature of PE care, the interventional radiologist (IR) needs to become an astute, disease-specific expert. This review article describes the following "steps" an IR can take to reach this level: (1) understand PE stratification and epidemiology; (2) recognize the treatment goals for massive PE; (3) recognize the wide range of attitudes toward therapeutic escalation for submassive PE; (4) recognize what we do not know about the treatment of submassive PE and the limitations of current studies; (5) know the literature surrounding inferior vena cava filter insertion for severe PE; (6) integrate into the longitudinal care of the patient; and (7) be at the leading edge of new trials and technologies.

Long-term right ventricular (RV) function, functional capacity, exercise capacity, and quality of life following pulmonary embolism (PE), and the impact of thrombolysis, are unclear. A systematic review of studies that evaluated these outcomes with 3-month mean follow-up after PE diagnosis was performed. For each outcome, random effects meta-analyses were performed. Twenty-six studies (3671 patients) with 18-month median follow-up were included. The pooled prevalence of RV dysfunction was 18.1%. Patients treated with thrombolysis had a lower, but not statistically significant, risk of RV dysfunction versus those treated with anticoagulation (odds ratio: 0.51, 95% CI: 0.24 to 1.13, p=0.10). Pooled prevalence of at least mild functional impairment (NYHA II-IV) was 33.2%, and at least moderate functional impairment (NYHA III-IV) was 11.3%. Patients treated with thrombolysis had a lower, but not statistically significant, risk of at least moderate functional impairment versus those treated with anticoagulation (odds ratio: 0.48, 95% CI: 0.15 to 1.49, p=0.20). Pooled 6-minute walk distance was 415 m (95% CI: 372 to 458 m), SF-36 Physical Component Score was 44.8 (95% CI: 43 to 46), and Pulmonary Embolism Quality of Life (QoL) Questionnaire total score was 9.1. Main limitations included heterogeneity among studies for many outcomes, variation in the completeness of data reported, and inclusion of data from non-randomized, non-controlled, and retrospective studies. Persistent RV dysfunction, impaired functional status, diminished exercise capacity, and reduced QoL are common in PE survivors. The effect of thrombolysis on RV function and functional status remains unclear.

BACKGROUND: The AngioVac (AngioDynamics, Latham, NY) device utilizes a venovenous bypass circuit for percutaneous venous thrombectomy and has been applied in the setting of iliocaval thrombosis as well as right heart thrombus and pulmonary emboli. We describe our experience with the AngioVac device in 12 patients with a variety of indications with the goal of identifying factors correlating with successful thrombectomy. METHODS: From August 2013 to June 2015, 12 patients underwent AngioVac percutaneous thrombectomy at our institution. Preoperative, intraoperative, and postoperative data were retrospectively analyzed. RESULTS: Indications for thrombectomy included iliocaval thrombosis in 33% (4), right heart thrombus in 42% (5), and pulmonary embolus in 25% (3). We experienced a 58% complete success rate. Partial success was achieved in 17%, and no thrombus was extracted in 25%. Iliocaval and right heart thrombi were the most amenable to AngioVac thrombectomy with 100% (4/4) and 60% (3/5) complete success rates, respectively. Pulmonary embolus was the least amenable to thrombectomy with a 33% partial success rate (1/3) and 67% failure rate (2/3). CONCLUSION: The AngioVac devices allow for percutaneous thrombectomy in the setting of iliocaval and right heart thrombus in patients for whom medical therapy fails or for those in whom surgical intervention is considered high risk. Pulmonary emboli are less amenable, likely due to limited steeribility of the device. Larger studies are needed to make more definitive conclusions, and newer iterations of the device will likely allow for improved outcomes.

This single-center, retrospective study describes using the VASCADE Vascular Closure System (Cardiva Medical, Inc, Santa Clara, California) to close 32 venous access sites in 21 consecutive patients (11 females; 10 males; age 45 y +/- 19) after catheter-directed interventions. Sheath sizes were 5-10 F (8.7 F +/- 1.7). Hemostasis was achieved in 30 of 32 deployments (93.8%). Complications were observed after 6 of 32 procedures, including 5 minor events in 4 patients and 1 major event in 1 patient which was likely unrelated to device deployment. The VASCADE device efficaciously closes venotomies after deep venous procedures, but further studies comparing it with manual compression are required to define its optimal use.

Patients with advanced post-thrombotic syndrome (PTS) and chronic iliac vein obstruction suffer major physical limitations and impairment of health-related quality of life. Currently there is a lack of evidence-based treatment options for these patients. Early studies suggest that imaging-guided, catheter-based endovascular therapy can eliminate iliac vein obstruction and saphenous venous valvular reflux, resulting in reduced PTS severity; however, these observations have not been rigorously validated. A multidisciplinary expert panel meeting was convened to plan a multicenter randomized controlled clinical trial to evaluate endovascular therapy for the treatment of advanced PTS. This article summarizes the findings of the panel, and is expected to assist in developing a National Institutes of Health-sponsored clinical trial and other studies to improve the care of patients with advanced PTS.