Leveraging the virtual learning environment to enhance medical student engagement with interventional radiology.

PURPOSE: To evaluate medical student engagement with Interventional Radiology (IR) before and after a virtual elective course. METHODS: The elective was nine, one-hour lectures over ten weeks. An anonymous pre and post-course survey was administered to students. The hypothesis was that this course would increase student engagement with IR. Respondents answered nine questions to score their interest in, exposure to, familiarity with, and understanding of IR using a five-point Likert scale. Demographics were reported for the pre-course group only. A Wilcoxon signed-ranked test was performed to assess for significant mean change in pre and post-course responses. Among the 276 registered students, there were 144 individual, complete responses for the pre-course survey, and 60 paired responses for both surveys. RESULTS: Thirty-seven percent of respondents were first or second year medical students. Thirty percent of participants were enrolled at an institution outside of the United States, 26% are the first in their family to attend college, and 41% identified as female. Thirty-six percent reported this virtual course was one of their earliest experiences with IR. There was a significant increase in student exposure to IR generally, familiarity with IR compared to other specialties, familiarity with the IR training pathway(s), understanding of what an Interventional Radiologist does, understanding of the difference between IR and Diagnostic Radiology, and understanding of when to consult IR for patient care after completion of the course. CONCLUSION: A virtual IR elective is an effective means to increase exposure to, familiarity with, and understanding of IR.

Double-barrel iliocaval reconstruction using closed-cell dedicated venous stents.

OBJECTIVE: Double-barrel iliocaval reconstruction is performed by deploying two stents simultaneously in a side-by-side, or "double-barrel," configuration in the inferior vena cava (IVC) with extension into the bilateral common iliac veins. The aim of this study was to examine the outcomes of double-barrel reconstruction using closed-cell dedicated venous stents for the treatment of iliocaval deep venous thrombosis and iliac vein compression syndrome. METHODS: All endovascular procedural reports comprising vascular surgery and interventional radiology operators from a single urban academic hospital between May 1, 2019, and April 30, 2021, were retrospectively searched. A cohort of 22 consecutive patients who underwent double-barrel iliocaval stenting with closed-cell dedicated venous stents for chronic or acute-on-chronic iliocaval venous disease without prior endovascular iliocaval repair was identified. Baseline characteristics, procedural data, and patient outcomes were determined via a manual review of preprocedure clinical notes, diagnostic imaging studies, procedure notes and images, and follow-up clinical notes. RESULTS: The median (range) age was 59 (27-81) years, and the cohort consisted of 59.1% female. The most common presenting symptoms of venous disease were lower extremity swelling (90.9%) and pain (50.0%). CEAP clinical classification was C3 in 86.4% of patients, whereas the remainder had C4 disease. Most patients (72.7%) had post-thrombotic syndrome, 22.7% had a nonthrombotic iliac vein lesion, and one patient (4.5%) had the congenital absence of the infrarenal IVC. A total of 40.9% of patients had a pre-existing IVC filter at the time of treatment. Six of the 22 patients underwent concurrent pharmacomechanical thrombectomy during the index iliocaval reconstruction and stenting procedure. The number of stents placed ranged from 2 to 5. With a mean follow-up period of 7.1 months, ranging from 12 days to 16.7 months, the freedom from reintervention rate was 90.9%. Twenty of 22 patients achieved subjective improvement or resolution of symptoms. The major adverse event rate was 9.1%, as two patients had access site complications requiring intervention. CONCLUSIONS: Double-barrel iliocaval reconstruction with closed-cell dedicated venous stents for the treatment of post-thrombotic syndrome or iliac vein compression syndrome is technically feasible and clinically effective with a low reintervention rate.

Contemporary Management of Acute Pulmonary Embolism: Evolution of Catheter-based Therapy.

Acute pulmonary embolism (PE) affects more than 100 000 people in the United States annually and is the third leading cardiovascular cause of death. The standard management for PE is systemic anticoagulation therapy. However, a subset of patients experience hemodynamic decompensation, despite conservative measures. Traditionally, these patients have been treated with systemic administration of thrombolytic agents or open cardiac surgery, although attempts at endovascular treatment have a long history that dates back to the 1960s. The technology for catheter-based therapy for acute PE is rapidly evolving, with multiple devices approved over the past decade. Currently available devices fall into two broad categories of treatment methods: catheter-directed thrombolysis and percutaneous suction thrombectomy. Catheter-directed thrombolysis is the infusion of thrombolytic agents directly into the occluded pulmonary arteries to increase local delivery and decrease the total dose. Suction thrombectomy involves the use of small- or large-bore catheters to mechanically aspirate a clot from the pulmonary arteries without the need for a thrombolytic agent. A thorough understanding of the various risk stratification schemes and the available evidence for each device is critical for optimal treatment of this complex entity. Multiple ongoing studies will improve our understanding of the role of catheter-based therapy for acute PE in the next 5-10 years. A multidisciplinary approach through PE response teams has become the management standard at most institutions. An invited commentary by Bulman and Weinstein is available online. Online supplemental material is available for this article. ©RSNA, 2022.

Intrahepatic flow diversion prior to segmental Yttrium-90 radioembolization for challenging tumor vasculature.

Background: Hepatic tumors with complex vascular supply or poor relative perfusion are prone to decreased rates of objective response. This is compounded in the setting of Yttrium-90 (Y90) transarterial radioembolization (TARE), which is minimally embolic and flow-dependent, relying on high threshold dose for complete response. Objective: We describe our experience with intrahepatic flow diversion (FD) prior to TARE of hepatocellular carcinoma (HCC) with challenging vascular supply. Materials and methods: Between April 2014 and January 2020, 886 cases of coinciding MAA or TARE and bland embolization or temporary occlusion were identified. Intraprocedural embolizations performed for more routine purposes were excluded. FD was performed by bland embolization or temporary occlusion of vessels supplying non-malignant parenchyma in cases where flow was not preferential to target tumor. Lesion characteristics, vascular supply, treatment approach, angiography, and adverse events (AEs) were reviewed. Radiographic response was assessed using mRECIST criteria. Results: 22 cases of FD of focal HCC were identified. Embolics included calibrated microspheres (n â€‹= â€‹11), microcoils (n â€‹= â€‹4), gelfoam (n â€‹= â€‹3), temporary balloon occlusion (n â€‹= â€‹2) and temporary deployment of a microvascular plug (n â€‹= â€‹1). Post-treatment SPECT-CT dosimetry coverage was concordant with target lesions in all cases. Mean follow-up was 16.7 months (1.4-45 â€‹mos). Tumor-specific response per mRECIST was 41% complete response, 50% objective response, and 59% disease control rate. No major adverse events or grade 3/4 hepatotoxicity were reported. Conclusion: Our findings suggest that FD prior to TARE is safe and potentially effective in treating HCC with complex vascular supply or poor tumor perfusion.

Survival Analysis Using Albumin-Bilirubin (ALBI) Grade for Patients Treated with Drug-Eluting Embolic Transarterial Chemoembolization for Hepatocellular Carcinoma.

PURPOSE: The albumin-bilirubin (ALBI) grade has been established as an improved predictor of survival in patients with hepatocellular carcinoma (HCC) treated with conventional transarterial chemoembolization and yttrium-90 radioembolization. The purpose of the study was to investigate the utility of ALBI grade in prognosticating outcomes in patients with HCC treated with drug-eluting embolic (DEE) transarterial chemoembolization (TACE). MATERIALS AND METHODS: A single-center retrospective review was performed to compare the efficacy of ALBI grade and Child-Pugh (CP) classification in predicting the survival of patients with HCC receiving DEE-TACE. A total of 303 patients with HCC were identified who had received DEE-TACE without concomitant locoregional therapy within 30 days. Survival analysis was performed using Kaplan-Meier methods and censored for curative therapy. Survival curves were stratified based on the ALBI grade, CP class, Barcelona Clinic Liver Cancer (BCLC) stage, Eastern Cooperative Oncology Group performance status, and presence of ascites. The discriminatory ability of survival curves was calculated by C-Index. RESULTS: Kaplan-Meier survival curves stratified by the ALBI grade produced distinct, nonoverlapping curves (P < .001), showing greater discriminatory ability than the CP classification (C-index = 0.568 and 0.545, respectively). The substratification of the BCLC stage by the ALBI grade yielded greater discriminatory ability than the substratification by the CP classification (C-index = 0.573 and 0.565, respectively). For patients with BCLC stage B, the substratification by the ALBI grade yielded distinct curves, whereas the substratification by the CP classification did not (P = .011 and P = .379, respectively). CONCLUSIONS: ALBI grade showed improved discriminatory ability compared with CP classification in differentiating overall survival among patients with HCC receiving DEE-TACE. Furthermore, ALBI grade was effective in substratifying survival among patients categorized as CP class A and patients with BCLC stage B, whereas CP classification was not effective.

FlowTriever Retrieval System for the treatment of pulmonary embolism: overview of its safety and efficacy.

INTRODUCTION: Pulmonary embolism (PE) is the third leading cause of cardiovascular mortality. There has been little change in PE mortality rates over the past two decades making this an appealing area for innovation and development. AREAS COVERED: While anticoagulation (AC) and systemic thrombolysis (ST) are the mainstay treatments for high-risk PE and intermediate-high-risk PE with decompensation, advancements in catheter- based therapies offer potential alternatives. Areas covered here will include present guidelines for PE treatment and the landscape of catheter-directed therapies with a focus on the FlowTriever (FT) Retrieval System. Available safety and efficacy data will be reviewed. An online search via Google Scholar and PubMed with the keywords INARI Flowtriever, venous thromboembolism, and pulmonary embolism, alongside bibliographies of published articles, was undertaken as a review of the literature on the FlowTriever system for this device overview. EXPERT OPINION: The five-year outlook on the role of catheter-directed therapies in the management of PE includes continued innovation in catheter-directed therapies and a number of high-quality trials on the horizon.

Pre-operative endovascular occlusion for unresectable metastatic carcinoid tumor: technique and initial results.

PURPOSE: Surgery is the only curative therapy for carcinoid patients; however, many are unresectable due to direct involvement of the superior mesenteric artery (SMA) branches. In these patients, we sought to improve surgical outcomes via arterial skeletonization of the SMA prior to surgical resection. MATERIALS AND METHODS: After left radial access, the SMA was catheterized, angiography was performed, and balloon occlusion was achieved in the tumor vessel. Following balloon occlusion of the affected artery, patients were assessed for symptoms of ischemia and angiographic evidence of distal perfusion via collaterals. If patients tolerated occlusion, an endovascular plug was deployed in the affected artery; if not, the procedure was terminated. The next day, all patients underwent exploratory laparotomy and surgical resection of tumor and bowel. RESULTS: The procedure was performed 15 times on 14 patients. 13 out of 15 procedures went to embolization, while the other 2 proceeded to surgery without plug deployment. One of the embolized patients had serious post-surgical complications, while both non-embolized patients developed complications including short bowel syndrome and ischemic colitis. Length of stay between embolized and non-embolized patients was equal, but re-admittance within 30 days was 7.7% in the embolized group and 100% in the non-embolized group. DISCUSSION: Our initial experience demonstrates feasibility and safety of deploying plugs within branches of the SMA prior to surgical resection and improved surgical outcomes. Palpation of the plug assisted in surgical resection. We have demonstrated that pre-operative endovascular occlusion is a safe, practical procedure, which aids surgical resection of mesenteric carcinoid disease.

Transfemoral Filter Eversion Technique following Unsuccessful Retrieval of Option Inferior Vena Cava Filters: A Single Center Experience.

This report describes the technical feasibility of using the filter eversion technique after unsuccessful retrieval attempts of Option and Option ELITE (Argon Medical Devices, Inc, Athens, Texas) inferior vena cava (IVC) filters. This technique entails the use of endoscopic forceps to evert this specific brand of IVC filter into a sheath inserted into the common femoral vein, in the opposite direction in which the filter is designed to be removed. Filter eversion was attempted in 25 cases with a median dwell time of 134 days (range, 44-2,124 d). Retrieval success was 100% (25/25 cases), with an overall complication rate of 8%. This technique warrants further study.

Radiation Segmentectomy versus TACE Combined with Microwave Ablation for Unresectable Solitary Hepatocellular Carcinoma Up to 3 cm: A Propensity Score Matching Study.

Purpose To compare the outcomes of radiation segmentectomy (RS) and transarterial chemoembolization (TACE) combined with microwave ablation (MWA) in the treatment of unresectable solitary hepatocellular carcinoma (HCC) up to 3 cm. Materials and Methods This retrospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. From January 2010 to June 2015, a total of 417 and 235 consecutive patients with HCC underwent RS and TACE MWA, respectively. A cohort of 121 patients who had not previously undergone local-regional therapy (RS, 41; TACE MWA, 80; mean age, 65.4 years; 84 men [69.4%]) and who had solitary HCC up to 3 cm without vascular invasion or metastasis was retrospectively identified. Outcomes analyzed included procedure-related complications, laboratory toxicity levels, imaging response, time to progression (TTP), 90-day mortality, and survival. Propensity score matching was conducted by using a nearest-neighbor algorithm (1:1) to account for pretreatment clinical, laboratory, and imaging covariates. Postmatching statistical analysis was performed with conditional logistic regression for binary outcomes and the stratified log-rank test for time-dependent outcomes. Results Before matching, the complication rate was 8.9% and 4.9% in the TACE MWA and RS groups, respectively (P = .46). The overall complete response (CR) rate was 82.9% for RS and 82.5% for TACE MWA (odds ratio, 1.0; 95% confidence interval [CI]: 0.4, 2.8; P = .95). There were 41 (RS, 11; TACE MWA, 30) instances of progression occurring after an initial CR, of which 10 (24%) were classified as target progression (RS, one; TACE MWA, nine). Median overall TTP was 11.1 months (95% CI: 8.8 months, 25.6 months) in the RS group and 12.1 months (95% CI: 7.7 months, 19.1 months) in the TACE MWA group (P > .99). After matching, the overall CR rate (P = .94), TTP (P = .83), and overall survival (P > .99) were not significantly different between the two groups. The 90-day postoperative mortality rate was 0% in both groups. Conclusion Imaging response and progression outcomes of patients with solitary HCC up to 3 cm treated with RS were not significantly different when compared with those of patients treated with TACE MWA. © RSNA, 2016 Online supplemental material is available for this article.

Transradial Approach for Hepatic Radioembolization: Initial Results and Technique.

OBJECTIVE: The transradial approach (TRA) has been shown to reduce the morbidity and mortality associated with arterial coronary interventions. Selective internal radiation therapy (SIRT) performed via the TRA can enhance patient comfort, compared with the traditional transfemoral approach (TFA), by allowing immediate ambulation and precluding potential complications associated with the TFA, such as closure device injury or retroperitoneal hematoma. We report our initial experience with and technique for using the TRA for SIRT. MATERIALS AND METHODS: Between May 1, 2012, and April 30, 2015, a total of 574 procedures, including planning angiograms (n = 329) and infusions of 90Y (n = 245), were performed for 318 patients (mean age, 64.5 years). Of the 245 patients who received 90Y infusions, 52 had SIRT performed with the use of a permanent single-use implant of 90Y resin microspheres and 193 had SIRT performed with the use of millions of small glass microspheres containing radioactive 90Y. Procedural details, technical success, the radial artery (RA) occlusion rate noted at 30 days (as assessed via pulse examination), and the major and minor adverse events noted at 30 days were evaluated. RESULTS: Technical success was achieved in 561 of 574 cases (97.7%). The reasons for crossover to use of the TFA included an RA loop (n = 2), RA occlusion (n = 9), and type D response as determined by use of a Barbeau test (n = 2). Patients had undergone between zero and six previous TRA procedures. The mortality rate at 30 days was 0%. Superficial bruising occurred in 13 of 574 cases (2.3%). A grade 2 hematoma that required a second nonocclusive hemostasis cuff occurred in one case. Transient forearm numbness or pain occurred in two of 574 cases. One patient had a transient convulsive event occur after receiving intraarterial infusion of verapamil. RA occlusion occurred in nine of 574 cases (1.6%). CONCLUSION: Use of the TRA for SIRT is safe, feasible, and well tolerated and is associated with high rates of technical success and rare complications.

Embolization of giant renal angiomyolipomas: technique and results.

PURPOSE: To evaluate the efficacy and safety of prophylactic embolization of angiomyolipomas (AMLs) larger than 10 cm. MATERIALS AND METHODS: Sixteen patients (mean age, 41.2 years; 14 women and two men) underwent embolization for 23 AMLs larger than 10 cm. All lesions were embolized by using microcatheters with ethanol and ethiodized oil mixed to a ratio of 7(ethanol) to 3(ethiodized oil). Data collected included pre- and posttreatment AML size, creatinine level, technical success, volume of embolic material used, clinical success, and complications. RESULTS: The mean AML size before treatment was 15 cm (range, 10-25 cm). Ten of the 16 patients (62%) had all their AMLs treated in one session, whereas six (38%) required multiple sessions. A mean volume of 8.6 mL of the ethanol-ethiodized oil mixture (range, 2-20 mL) was administered per lesion. Patients were followed up for a mean of 29 months (range, 1-80 months). No patient had an increase of 0.2 mg/dL (17.7 mumol/L) or greater in mean serum creatinine level during the follow-up period. Two of the 16 patients (12%) required repeat embolization due to AML regrowth (n = 1) or reperfusion (n = 1) seen at surveillance imaging. One of the 16 patients (6.2%) had an AML hemorrhage 59 months after AML embolization. CONCLUSIONS: Embolization of giant renal AMLs to decrease the risk of bleeding can be done safely without loss of renal function. Although recurrence was infrequent, additional treatment may be necessary and giant renal AMLs should be followed up with serial imaging studies.