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.

Comparison of 24-Month Clinical Outcomes after Prostatic Artery Embolization in Prostate Glands Larger versus Smaller than 80 mL: A Systematic Review

PURPOSE

This review was undertaken to compare the clinical outcomes of prostatic artery embolization (PAE) in patients with >80 versus <80 mL prostatic volume (PV) at the 24-month follow-up to determine whether PV predicted the effectiveness or durability of PAE.

MATERIALS AND METHODS

The PubMed/MEDLINE database was searched for articles published between 2010 and 2022 using the search term "(prostat∗ artery embolization) AND (long term OR follow-up OR 24-month)." Articles were included if they discussed PAE for benign prostatic hyperplasia (BPH) and reported a minimum follow-up of 24 months. Articles with <10 patients were excluded. A subgroup analysis was performed to evaluate for any difference in clinical outcomes at the 24-month post-PAE follow-up between studies with a mean PV of >80 mL and those with a mean PV of <80 mL.

RESULTS

A total of 14 studies with 2,260 patients were included, all of which demonstrated significant reduction in symptoms at the 24-month follow-up after PAE. Four studies were included as part of the >80-mL PV subgroup (n = 467), and 10 studies were included as part of the <80-mL PV subgroup (n = 1,793). There was a statistically significant difference between the mean preprocedural PV (128.5 vs 64.0 mL; P = .015). At the 24-month follow-up, there were no significant differences between groups across any of the compared parameters. The collective incidence of major adverse events reported in the studies within this review was <1%.

CONCLUSIONS

PAE is both safe and durable for patients suffering from BPH and can be effective across a wide range of baseline PVs.

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 ​= ​11), microcoils (n ​= ​4), gelfoam (n ​= ​3), temporary balloon occlusion (n ​= ​2) and temporary deployment of a microvascular plug (n ​= ​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 ​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 ALBI Grade for Patients Treated with DEE-TACE 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 (TACE) and yttrium-90 radioembolization. We investigate the viability of ALBI grade in prognosticating HCC patients treated with drug-eluting embolic (DEE)-TACE.

MATERIALS AND METHODS

An IRB-approved, single-center retrospective review was performed to compare the efficacy of ALBI grade and Child-Pugh (CP) classification in predicting survival of HCC patients receiving DEE-TACE. 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 (KM) methods and censored for curative therapy. Survival curves were stratified based on ALBI grade, CP class, Barcelona Clinic Liver Cancer (BCLC) stage, Eastern Cooperative Oncology Group (ECOG) performance status and presence of ascites. Discriminatory ability of survival curves was calculated by C-Index.

RESULTS

Kaplan-Meier survival curves stratified by ALBI grade produced distinct, non-overlapping curves (p < 0.001), showing greater discriminatory ability compared to CP class (C index = 0.568, 0.545, respectively). Substratification of BCLC by ALBI grade yielded greater discriminatory ability compared to substratification by CP class (C index = 0.573, 0.565, respectively). For BCLC B patients, substratification by ALBI grade yielded distinct curves while substratification by CP class did not (p = 0.011, 0.379, respectively).

CONCLUSION

ALBI grade shows improved discriminatory ability versus CP class in differentiating overall survival among patients with HCC receiving DEE-TACE. Furthermore, ALBI grade was efficacious in substratifying survival among CP A patients, and substratified BCLC B patients whereas CP class did not.

Adjunctive Coil Embolization of the Prostatic Arteries After Particle Embolization for Prostatic Artery Embolization

PURPOSE

To describe the feasibility, safety and short-term results of prostatic artery embolization (PAE) performed with adjunctive coil embolization of the main prostatic arteries (PA) following particle embolization.

MATERIALS AND METHODS

A total of 95 patients who underwent PAE with adjunctive bilateral coil embolization of the PAs following particle embolization between September 2018 and May 2021 were included. The patients had a mean prostate size of 115 ± 64 ml, 18/95 with hematuria symptoms, and 16/95 with indwelling urinary catheters. Coil embolization was performed in the main PAs prior to the bifurcation into the anteromedial and posterolateral branches using detachable microcoils. International Prostate Symptoms Score (IPSS), quality of life (QOL), maximum flow rate (Qmax) and adverse events were recorded.

RESULTS

IPSS were improved by - 11.2 ± 7.9 (n = 49, P < 0.001) and QOL by - 2.4 ± 1.8 (n = 49, P < 0.001) over a mean follow-up of 10.7 ± 7.9 weeks. Qmax did not demonstrate statistical significance. Twelve patients with hematuria (67%) showed improvement or resolution and twelve patients with indwelling or intermittent catheters (75%) were no longer catheter dependent. Two patients underwent a repeat PAE. There were no adverse events which were attributable to coil embolization.

CONCLUSION

Adjunctive coil embolization of the main PAs following particle embolization is a technically feasible technique with similar short-term clinical outcomes compared to prior studies. This novel technique warrants further prospective investigation with controls.

Relationship of hospital volume on outcomes in patients with acute pulmonary embolism: Analysis of a 70,000 patient database

Positive relationships between volume and outcome have been seen in several surgical and medical conditions, resulting in more centralized and specialized care structures. Currently, there is a scarcity of literature involving the volume–outcome relationship in pulmonary embolism (PE). Using a state-wide dataset that encapsulates all non-federal admissions in New York State, we performed a retrospective cohort study on admitted patients with a diagnosis of PE. A total of 70,443 cases were separated into volume groups stratified by hospital quartile. Continuous and categorical variables were compared between cohorts. Multivariable regression analysis was conducted to assess predictors of 1-year mortality, 30-day all-cause readmission, 30-day PE-related readmission, length of stay, and total charges. Of the 205 facilities that were included, 128 (62%) were labeled low volume, 39 (19%) medium volume, 23 (11%) high volume, and 15 (7%) very high volume. Multivariable analysis showed that very high volume was associated with decreased 30-day PE-related readmission (OR 0.64; 95% CI, 0.55 to 0.73), decreased 30-day all-cause readmission (OR 0.84; 95% CI, 0.79 to 0.89), decreased 1-year mortality (OR 0.85; 95% CI, 0.80 to 0.91), decreased total charges (OR 0.96; 95% CI, 0.94 to 0.98), and decreased length of stay (OR 0.94; 95% CI, 0.92 to 0.96). In summary, facilities with higher volumes of acute PE were found to have less 30-day PE-related readmissions, less all-cause readmissions, shorter length of stay, decreased 1-year mortality, and decreased total charges.

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.

Use of 70- to 150-μm Radiopaque Spherical Embolics for Prostatic Artery Embolization

This retrospective report describes treatment of 21 patients who underwent prostatic artery embolization using 70- to 150-μm radiopaque microspheres for lower urinary tract symptoms secondary to benign prostatic hyperplasia. Seventeen patients (81%) received successful bilateral prostatic artery embolization. At a mean follow-up of 42 days (range, 25-59 days), patients showed improvement in International Prostate Symptom Score (n = 11; mean = 10.6; P = .001), quality of life score (n = 17; mean = 2.0; P = .02), and International Index of Erectile Function (n = 17; mean = 9.3; P = .01). The mean prostate volume reduction was 28 mL (16.2%; P = .003). Nontarget embolization occurred twice, resulting in 1 minor adverse event of hematospermia.

Inline Balloon Occlusion-Assisted Delivery of Ethylene Vinyl Alcohol Copolymer for Peripheral Arterial Applications: A Multicenter Case Series

PURPOSE

To assess the feasibility, safety, and efficacy of balloon-assisted delivery of ethylene vinyl alcohol copolymer (EVOH) for a range of peripheral arterial applications.

MATERIALS AND METHODS

Six academic medical centers entered retrospective data on 46 consecutive patients (27 men, 19 women; ages, 11-94 y; mean age, 50.3 y) who underwent 60 balloon-assisted EVOH procedures. The cohort was restricted to procedures involving peripheral, nonneural arteries 1-5.5 mm in diameter. Clinical indications included a wide range of vascular pathologic conditions (most commonly arteriovenous malformations [n = 20], renal angiomyolipomas [n = 8], and acute hemorrhage [n = 9]) and targeted visceral and musculoskeletal peripheral arteries. Data collected included sex, age, clinical indication, arterial pathology, arteries embolized, type of occlusion balloon microcatheter, type and concentration of EVOH agent, effectiveness as an embolic backstop, vessels protected, adequacy of EVOH cast penetration, catheter extraction, nontarget embolization, and complications.

RESULTS

Balloon occlusion prevented EVOH reflux in 59 of 60 procedures (98.3%). Nontarget EVOH embolization occurred in 2 procedures (3.3%). Adequate EVOH cast penetration and complete filling of the target pathologic structure were seen in 57 of 60 procedures (95%). Balloon deflation and uneventful extraction occurred in all procedures; small EVOH fragments detached into target arteries in 2 cases. One major (1.7%) and 2 minor (3.3%) complications occurred.

CONCLUSIONS

Balloon-assisted EVOH embolization of peripheral arteries is feasible, safe, effective, and versatile. The primary advantage of balloon-assisted EVOH embolization is the ability to apply more injection pressure to advance the EVOH cast assertively into the pathologic structure(s).

Patient Experience and Preference in Transradial versus Transfemoral Access during Transarterial Radioembolization: A Randomized Single-Center Trial

PURPOSE

To determine patient preference for transradial access (TRA) or transfemoral access (TFA) after experiencing both.

MATERIALS AND METHODS

A randomized controlled crossover trial was conducted at a single institution. Thirty patients with hepatocellular carcinoma undergoing mapping and transarterial radioembolization (TARE) were enrolled to experience 1 TRA and 1 TFA procedure each, with randomization of which access approach was experienced first. Surveys assessing pain and quality of life (QOL) were administered after each procedure. Access site preference was collected after completion of both procedures.

RESULTS

Twenty-two subjects (73.3%) preferred TRA, 4 (13.3%) preferred TFA, and 4 (13.3%) had no preference; 14 (46.7%) reported bruising after TRA, and 17 (53.3%) reported bruising after TFA. TRA was associated with significantly lower pain scores overall during the procedure, at the access site during the procedure, and in the recovery room compared with TFA (2.0 vs 2.9, P = .0046; 2.0 vs 3.0, P = .0004; 2.1 vs 2.9, P = .0357). Pain score after discharge was not significantly different (1.4 vs 1.5, P = .4235). QOL scores were not significantly different between TRA and TFA. No significant differences were found for fluoroscopy time, air kerma, dose-area product, or procedure time between TRA and TFA for either mapping (P = .1442, P = .5871, P = .6667, P = .6131) or radioembolization (P = .8574, P = .2344, P = .1119, P =.8474). For radioembolizations, TRA had significantly shorter recovery times compared with TFA (108 min vs 153 min, P = .0193).

CONCLUSIONS

Patients exhibited a strong preference for TRA. With TRA, patients experienced less periprocedural pain and shorter recovery times without significant differences in radiation exposure or procedure length.

Balloon-Occluded Transarterial Chemoembolization for the Treatment of Hepatocellular Carcinoma: A Single-Center US Preliminary Experience

This report describes a single-center experience with balloon-occluded transarterial chemoembolization for liver-directed therapy. A total of 26 patients (11 male, 4 female; mean age, 65 y ± 7) with 28 tumors (mean diameter, 2.7 cm; range, 1.1-5.9 cm) were treated. Technical success rate was 100% (28 of 28 cases), with 1 minor complication of left portal vein thrombosis and small liver infarct. Of the 15 tumors analyzed for response, 60% (9 of 15) exhibited complete response, 33.3% (5 of 15) exhibited partial response, and 6.6% (1 of 15) had stable disease on follow-up. Eight patients exhibited overall progression with a new hepatic lesion and a median time to progression of 7.9 months (range, 5-11 mo).

Retrieval of Inferior Vena Cava Filters Temporarily Placed in a Suprarenal Position: A Review of 13 Patients

Purpose:

To evaluate the safety and efficacy of retrieval of inferior vena cava filters (IVCF) temporarily placed in a suprarenal position.

Methods:

Retrieval of IVCF placed in a suprarenal position was performed in 13 patients (5 men and 8 women; mean age: 45.1 ± 13.8 years) between July 2006 and May 2018 using either a loop snare technique or endobronchial forceps. Electronic medical records were reviewed for patient demographics and procedural information.

Results:

Inferior vena cava filters retrieved included Option Elite (n = 9, 69%) and Günther Tulip (n = 4, 31%). Caval thrombosis was not detected in any patients on pre- or postretrieval cavogram. Eleven suprarenal IVCF (84%) were retrieved during the first retrieval attempt after a median indwelling time of 1.8 months (range, 0.03-12.10 months). Retrieval was initially unsuccessful in 2 (16%) patients with Option Elite filters, but both were successfully removed on second attempt using endobronchial forceps. Thirteen suprarenal IVCF (100%) were ultimately retrieved.

Conclusion:

Endovascular retrieval of IVCF temporarily placed in a suprarenal position is safe and efficacious.

Bariatric Embolization of Arteries for the Treatment of Obesity (BEAT Obesity) Trial: Results at 1 Year

Background Bariatric embolization is a new endovascular procedure to treat patients with obesity. However, the safety and efficacy of bariatric embolization are unknown. Purpose To evaluate the safety and efficacy of bariatric embolization in severely obese adults at up to 12 months after the procedure. Materials and Methods For this prospective study (NCT0216512 on ClinicalTrials.gov ), 20 participants (16 women) aged 27-68 years (mean ± standard deviation, 44 years ± 11) with mean body mass index of 45 ± 4.1 were enrolled at two institutions from June 2014 to February 2018. Transarterial embolization of the gastric fundus was performed using 300- to 500-µm embolic microspheres. Primary end points were 30-day adverse events and weight loss at up to 12 months. Secondary end points at up to 12 months included technical feasibility, health-related quality of life (Short Form-36 Health Survey ([SF-36]), impact of weight on quality of life (IWQOL-Lite), and hunger or appetite using a visual assessment scale. Analysis of outcomes was performed by using one-sample t tests and other exploratory statistics. Results Bariatric embolization was performed successfully for all participants with no major adverse events. Eight participants had a total of 11 minor adverse events. Mean excess weight loss was 8.2% (95% confidence interval [CI]: 6.3%, 10%; P < .001) at 1 month, 11.5% (95% CI: 8.7%, 14%; P < .001) at 3 months, 12.8% (95% CI: 8.3%, 17%; P < .001) at 6 months, and 11.5% (95% CI: 6.8%, 16%; P < .001) at 12 months. From baseline to 12 months, mean SF-36 scores increased (mental component summary, from 46 ± 11 to 50 ± 10, P = .44; physical component summary, from 46 ± 8.0 to 50 ± 9.3, P = .15) and mean IWQOL-Lite scores increased from 57 ± 18 to 77 ± 18 (P < .001). Hunger or appetite decreased for 4 weeks after embolization and increased thereafter, without reaching pre-embolization levels. Conclusion Bariatric embolization is well tolerated in severely obese adults, inducing appetite suppression and weight loss for up to 12 months. Published under a CC BY-NC-ND 4.0 license. Online supplemental material is available for this article.

Radial Access for Lower Extremity Peripheral Arterial Interventions: Do We Have the Tools?

The benefits of transradial arterial access (TRA) versus transfemoral arterial access (TFA) have been extensively described in the literature; however, TFA remains the predominant access site choice in the management of peripheral arterial disease (PAD). There are still significant unmet needs for operators wishing to provide the same effective interventions for lower extremity PAD via TRA as with TFA. This article provides an up-to-date review of the literature and devices currently available for operators wishing to treat lower extremity PAD via TRA and the limitations they may face.

End-hole Versus Microvalve Infusion Catheters in Patients Undergoing Drug-Eluting Microspheres-TACE for Solitary Hepatocellular Carcinoma Tumors: A Retrospective Analysis

INTRODUCTION

Pre-transplant locoregional therapy for hepatocellular carcinoma (HCC) during bridge-to-transplant impacts recurrence and survival rates following liver transplantation. Optimizing the effectiveness of transarterial chemoembolization (TACE) in this population is imperative, and microvalve infusion catheters offer a means of such improvement.

METHODS

All treatment-naive patients with solitary HCC tumors < 6.5 cm who underwent drug-eluting microspheres (DEM) TACE between 04/2015 and 08/2017 were retrospectively reviewed. Eighty-eight included patients underwent DEM-TACE with either standard end-hole catheters (EH) or microvalve infusion catheters (MVI). The EH (n = 70) and MVI (n = 18) cohorts had similar baseline tumor size, laboratory values, and tumor etiologies.

RESULTS

Initial objective response rates were significantly higher in MVI vs. EH (100% vs. 76.5%, p = 0.019). There was no difference in adverse events between groups (p = 0.265). MVI patients exhibited lower AST (p = 0.003) and ALT (p = 0.044) at 6 months. Blinded pathological analysis of explanted livers showed greater concentrations of microspheres within the tumor relative to the surrounding tissue in MVI explants (88.7 ± 10.6%) versus the EH explants (55.3 ± 32.7%) (p = 0.002). There was significantly higher percentage tumor necrosis in the MVI group (89.0 ± 2.2%) compared with the EH group (56.1 ± 44.5%) (p = 0.006).

CONCLUSION

In this retrospective study of a single-center cohort, DEM-TACE procedures with MVI were associated with improved tumor response, increased deposition of microspheres within tumor tissue, and higher percentage tumor necrosis at explant relative to those performed using EH catheters.

The State of Medical Student Teaching of Interventional Radiology: Implications for the Future

INTRODUCTION

The formation of integrated interventional radiology (IR) residency programs has changed the training paradigm. This change mandates the need to provide adequate exposure to allow students to explore IR as a career option and to allow programs to sufficiently evaluate students. This study aims to highlight the availability of medical student education in IR and proposes a basic framework for clinical rotations.

MATERIALS AND METHODS

The Liaison Committee on Medical Education (LCME) website was utilized to generate a list of accredited medical schools in the United States. School websites and course listings were searched for availability of IR and diagnostic radiology rotations. The curricula of several well-established IR rotations were examined to identify and categorize course content.

RESULTS

In all, 140 LCME-accredited medical schools had course information available. Of those schools, 70.5% offered an IR rotation; 84.6% were only available to senior medical students and only 2% were offered for preclinical students; and 8.1% of courses were listed as subinternships. Well-established IR clerkships included a variety of clinical settings, including preprocedure evaluation, experience performing procedures, postprocedure management, and discharge planning.

CONCLUSION

Medical student exposure to IR is crucial to the success of integrated IR residency programs. Current research shows few institutions with formal IR subinternship rotations. Although 70.5% of institutions have some form of nonstandardized IR course, 84.6% are available only to fourth-year students, and 2% are offered to preclinical students. This suggests there is a significant opportunity for additional formal exposure to IR through increasing availability of IR rotations and exposure during the clinical and preclinical years.

Patient Radiation Exposure in Transradial versus Transfemoral Yttrium-90 Radioembolization: A Retrospective Propensity Score-Matched Analysis

PURPOSE

To compare differences in patient radiation exposure (PRE) during transarterial yttrium-90 (⁹⁰Y) radioembolization (TARE) between transradial access (TRA) and transfemoral access (TFA).

MATERIALS AND METHODS

A total of 810 consecutive first-time TARE procedures in patients from 2013 to 2017 were retrospectively reviewed. A propensity score-matching (PSM) analysis matched TRA and TFA groups on the basis of patient age, sex, weight, height, cancer type, ⁹⁰Y microsphere type, and number of previous procedures from the same and opposite approaches. Matched groups were then compared by PRE measures fluoroscopy time (FT), dose-area product (DAP), and cumulative air kerma (AK). Effect size for each PRE measure was calculated.

RESULTS

Before PSM, TRA and TFA groups differed significantly in mean age, weight, and number of previous procedures from the same and opposite approach (all P < .05). After PSM, each group consisted of 302 procedures (overall, n = 604) and no longer differed in any procedure performed before surgery measure. TRA did not differ from the matched TFA group regarding median FT (9.50 vs 9.40 minutes, P = .095), median DAP (67,066 vs 67,219 mGy·cm²; P = .19), or median AK (323.63 vs 248.46 mGy; P = .16). Effect sizes were 0.068, 0.054, and 0.110 for FT, DAP, and AK, respectively.

CONCLUSIONS

No statistical differences were found for PRE measures between the matched TRA and TFA approach groups. Furthermore, practical effect sizes were considered to be small for AK and less than small for FT and DAP, and therefore, any differences in PRE between the radial and femoral approaches for TARE are minor and unlikely to be noticeable in everyday clinical practice.

Outcomes of radioembolization for unresectable hepatocellular carcinoma in patients with marginal functional hepatic reserve

PURPOSE

To evaluate the outcomes of radioembolization (RE) as a therapy for unresectable hepatocellular carcinoma (HCC) in patients with marginal functional hepatic reserve.

METHODS

A retrospective review of 471 patients (1/2010-7/2015) treated with RE (Therasphere, BTG, UK) was performed. A total of 36 patients (mean age: 66.1±9.3, male: 86.1%) underwent therapy for HCC with a MELD≥15 (median: 16, range: 15-22). Baseline demographics of the study cohort were as follows: etiology (HCV: 26, 72.2%), cirrhosis (n=32, 88.9%), ECOG 0 (n=16, 44.4%), Child-Pugh class (A=15, B=19, C=2), unilobar distribution (n=27, 75%), AFP>200 (n=11, 30.6%), portal vein thrombosis (PVT, n=7, 19.4%), metastasis (n=3, 8.3%). Outcomes analyzed included CTCAEv4.03 laboratory toxicities (120-day), imaging response (mRECIST), progression-free survival (PFS), and overall survival (OS).

RESULTS

A total of 42 treatments were performed with mean dose of 2.02±1.23GBq. The cumulative grade 3/4 toxicity was 28% overall and 21% for bilirubin at 120-days. The objective response and disease control rates were 48.3% (14/29) and 69% (20/29) respectively. The median (95% CI) PFS was 5.9 (4.4-7.7) months. Ten (27.8%) patients received additional locoregional therapy at a median (IQR) of 138 (102-243) days post RE. The mean (95% CI) OS was 21.9 (14.8-29.0) months. The absence of PVT was associated with improved OS (p=0.005) Disease control at 90-days was also associated with an OS benefit (p=0.037).

CONCLUSIONS

Patients with unresectable HCC and marginal functional hepatic reserve treated with RE had favorable objective response and disease control rates, both predictive of overall survival.

Transradial Access for Interventional Radiology: Single-Centre Procedural and Clinical Outcome Analysis

PURPOSE

The study sought to describe a single centre's technical approach to transradial intervention and report on clinical outcomes and safety.

METHODS

A total of 749 transradial access (TRA) procedures were performed at a single hospital in 562 patients (174 women and 388 men). Procedures included 445 bland embolizations or chemoembolizations of the liver, 88 uterine artery embolizations, and 148 procedures for Selective Internal Radiation Therapy (Y90), which included mapping and administration. The mean age of the patients was 62 years (range 27-96 years).

RESULTS

Four cases (0.5%) required crossover to transfemoral (tortuous anatomy, inability to secure a stable position for embolization, vessel spasm and base catheter not being of a sufficient length). A single asymptomatic, short-segment radial artery occlusion occurred (0.3%), 3 patients (0.4%) developed small hematomas postprocedurally, and 2 patients (0.7%) had transient neurological pain, which was resolved within a week without treatment. It was found that 98% of patients who had a previous femoral access procedure would choose radial access for subsequent procedures.

CONCLUSIONS

Transradial access is a safe, effective technique, with a learning curve; however, this procedure has the potential to significantly improve departmental workflow and cost savings for the department and patient experience.

Clinical Safety of Bariatric Arterial Embolization: Preliminary Results of the BEAT Obesity Trial

Purpose To conduct a pilot prospective clinical trial to evaluate the feasibility, safety, and short-term efficacy of bariatric embolization, a recently developed endovascular procedure for the treatment of obesity, in patients with severe obesity. Materials and Methods This is an institutional review board- and U.S. Food and Drug Administration-approved prospective physician-initiated investigational device exemption study. This phase of the study ran from June 2, 2014, to August 4, 2015. Five severely obese patients (four women, one man) who were 31-49 years of age and who had a mean body mass index of 43.8 kg/m² ± 2.9 with no clinically important comorbidities were enrolled in this study. Transarterial embolization of the gastric fundus with fluoroscopic guidance was performed with 300-500-μm Embosphere microspheres. The primary end point was 30-day adverse events (AEs). The secondary end points included short-term weight loss, serum obesity-related hormone levels, hunger and satiety assessments, and quality of life (QOL) surveys, reported up to 3 months. Simple statistics of central tendencies and variability were calculated. No hypothesis testing was performed. Results The left gastric artery, with or without the gastroepiploic artery, was embolized in five patients, with a technical success rate of 100%. There were no major AEs. There were two minor AEs-subclinical pancreatitis and a mucosal ulcer that had healed by the time of 3-month endoscopy. A hospital stay of less than 48 hours for routine supportive care was provided for three patients. Mean excess weight loss of 5.9% ± 2.4 and 9.0% ± 4.1 was noted at 1 month and at 3 months, respectively. Mean change in serum ghrelin was 8.7% ± 34.7 and -17.5% ± 29 at 1 month and 3 months, respectively. Mean changes in serum glucagon-like peptide 1 and peptide YY were 106.6% ± 208.5 and 17.8% ± 54.8 at 1 month. There was a trend toward improvement in QOL parameters. Hunger/appetite scores decreased in the first 2 weeks after the procedure and then rose without reaching preprocedure levels. Conclusion Bariatric embolization is feasible and appears to be well tolerated in severely obese patients. In this small patient cohort, it appears to induce appetite suppression and may induce weight loss. Further expansion of this study will provide more insight into the long-term safety and efficacy of bariatric embolization. ^© RSNA, 2017 Online supplemental material is available for this article.

Radiation dose reduction utilizing noise reduction technology during uterine artery embolization: a pilot study

OBJECTIVE

To assess the radiation dose reduction during uterine artery embolization utilizing dose reduction technology.

METHODS

A total of 58 women underwent uterine artery embolization. A total of 26 procedures were performed in a standard fluoroscopy suite; 32 procedures were performed utilizing a novel imaging platform. Radiation dose data and acquisition parameters were compared.

RESULTS

The new platform provided significant reduction in the median radiation dose (P<.001): from 389Gy cm(2) to 145Gy cm(2). There were no differences between the groups with regard to acquisition parameters.

CONCLUSION

The new imaging platform provided a 61% dose reduction during uterine artery embolization without a significant change in acquisition parameters.

Yttrium-90 Glass-Based Microsphere Radioembolization in the Treatment of Hepatocellular Carcinoma Secondary to the Hepatitis B Virus: Safety, Efficacy, and Survival

PURPOSE

To evaluate outcomes of yttrium-90 radioembolization performed with glass-based microspheres in the treatment of hepatocellular carcinoma (HCC) secondary to the hepatitis B virus (HBV).

MATERIALS AND METHODS

A total of 675 patients treated between January 2006 and July 2014 were reviewed, of which 45 (age 62 y ± 10; 91% male) received glass-based radioembolization for HCC secondary to HBV. All patients were stratified according to previous therapy (naive, n = 14; 31.1%), Child-Pugh class (class A, n = 41; 91%), Eastern Cooperative Oncology Group (ECOG) performance status (PS; < 1, n = 21; 47%), solitary (n = 26; 58%) and unilobar (n = 37; 82%) tumor distribution, tumor size < 5 cm (n = 29; 64%), portal vein thrombosis (n = 14; 31%), α-fetoprotein level > 400 ng/mL (n = 17; 38%), and Barcelona Clinic Liver Cancer stage (A, n = 8; B, n = 9; C, n = 28).

RESULTS

A total of 50 radioembolization treatments were performed, with a 100% technical success rate (median target dose, 120 Gy). Clinical toxicities included pain (16%), fatigue (12%), and nausea (4%). Grade 3/4 laboratory toxicities included bilirubin (8%) and aspartate aminotransferase (4%) toxicities. Observed toxicities were independent of treatment dose. The objective response rates were 55% per modified Response Evaluation Criteria In Solid Tumors and 21% per World Health Organization criteria, and the disease control rate was 63%. Disease progression was secondary to new, nontarget HCC in 45% of cases. Median time to progression and overall survival were 6.0 mo (95% confidence interval [CI], 4.4-8.0 mo) and 19.3 mo (95% CI, 11.2-22.7 mo), respectively. Multivariate analysis demonstrated ECOG PS ≥ 1 and AFP level > 400 ng/mL to be independent predictors of inferior overall survival.

CONCLUSIONS

Glass-based radioembolization for HCC secondary to HBV can be safely performed, with favorable target lesion response and overall survival.

A Technical Guide Describing the Use of Transradial Access Technique for Endovascular Interventions

Transradial arterial access (TRA) has been employed for transcatheter coronary procedures for more than 25 years, with numerous studies demonstrating improved patient safety as compared with transfemoral arterial access. However, TRA remains underused by the interventional radiology and vascular surgery communities. Advantages of TRA over transfemoral arterial access include easier accomplishment of postprocedure hemostasis, decreased risk of hemorrhagic complications, shorter patient recovery leading to immediate ambulation and decreased procedure-related costs, and increased patient satisfaction. In particular, TRA may be advantageous in the population of patients with obesity. The primary patient selection factor to consider before attempting TRA is whether the patient has adequate collateral perfusion to the hand; this is assessed using the Barbeau test. Limitations of TRA may include operator unfamiliarity or learning curve and unavailability of adequate length catheters. The most common complication, although still rare, is localized access site hematoma, which is often asymptomatic. Radial artery occlusion is rare and rarely symptomatic owing to collateral perfusion to the hand. Theoretical increased risk of cerebral embolism during TRA may be minimized by preferentially accessing the left wrist during below-diaphragm procedures, which limits transcatheter manipulation of the aortic arch. Transulnar artery access is under investigation for use in patients who cannot undergo TRA. Providing patients the option of TRA can lead to improved outcomes, potentially increasing safety and patient satisfaction while decreasing procedure costs.

Tailoring the endovascular management of transplant renal artery stenosis

In this study we analyze the different types of endovascular interventions (EVIs) in de novo transplant renal artery stenosis (TRAS) and its anatomical subtypes to examine any variation in recovery of allograft function, blood pressure control, EVI patency and allograft survival with respect to EVI type (DES: drug-eluting stent, BMS: bare-metal stent, PTA: percutaneous transluminal angioplasty). Forty-five patients underwent a total of 50 primary EVIs (DES: 18, BMS: 26, PTA: 6). Patients were stratified according to medical co-morbidities, graft characteristics, biopsy results, clinical presentation and TRAS anatomic subtypes (anastomotic: 26, postanastomotic: 17, bend-kink: 2). There was significant improvement in allograft function and mean arterial blood pressure (MAP) control across all interventions (pre-EVI-creatinine [CR]: 2.8 ± 1.4, post-EVI-Cr: 2.1 ± 0.7, p < 0.001; pre-EVI-MAP: 117 ± 16, post-EVI-MAP: 112 ± 17, p = 0.03) with no significant difference among EVI types. There was no significant difference in allograft survival with respect to EVI type. Patency was significantly higher in EVIs performed with DES and BMS compared to PTA (p = 0.001). In the postanastomotic TRAS subtype, patency rates were significantly higher in DES compared to BMS (p = 0.012) in vessels of comparable reference diameter (≤5 mm).

Chemoembolization with drug-eluting microspheres (DEM-TACE) for hepatocellular carcinoma: single-center review of safety and efficacy

Purpose

This study examines the safety and efficacy of transarterial chemoembolization using doxorubicin-loaded 30–60 µm QuadraSphere microspheres (DEM-TACE) for the treatment of hepatocellular carcinoma.

Materials and methods

Over 10 weeks, patients with hepatocellular carcinoma. (Child–Pugh A/B: 65%/35%) were embolized with 30–60 µm QuadraSphere microspheres. Excluded patients had previous locoregional therapy, macrovascular invasion, extrahepatic disease, Child–Pugh score >B7, ECOG performance status >0, and total bilirubin >3 mg/dL. Technical success, minor and major complications, 30-day hospital readmission rate, and 30-day mortality were assessed. α-Fetoprotein levels before and after treatment were compared. Local response was evaluated by radiologic tumor response per modified Response Evaluation Criteria in Solid Tumors 1 month after treatment.

Results

Thirty tumors (mean size, 2.3 cm; range, 1.0–4.9 cm) were treated in 20 patients (16 male and 4 female; mean age, 64.7 years). There were no major complications. Thirty-day mortality was 0%. Minor complications included postembolization syndrome in 16.7% of cases and transient rise in liver enzymes requiring no therapy. Mean α-fetoprotein levels trended down following treatment (71.8±201.9 ng/mL vs 53.4±116.7 ng/mL), but were not statistically significant. Complete response was achieved in 30% of patients, partial response in 35%, stable disease in 30%, and progression of disease in 5%. Overall objective response was 65%. Mean follow-up was 10.4 months (range, 2–16.4 months).

Conclusion

DEM-TACE with doxorubicin-loaded 30–60 µm QuadraSpheres is feasible, well tolerated, and associated with promising tumor response in early and intermediate stage disease.

Percutaneous microwave ablation of renal tumors using a gas-cooled 2.4-GHz probe: technique and initial results

The feasibility, safety, and preliminary effectiveness of microwave ablation (MWA) in the treatment of renal tumors using a high-powered, carbon dioxide-cooled probe were evaluated. There were 15 tumors treated in 14 patients. Computed tomography was performed immediately after MWA, and follow-up imaging was performed to evaluate for recurrence. Immediate technical effectiveness was 100%. One complication involved the formation of a renal artery pseudoaneurysm. At follow-up (mean interval, 12.5 wk) evaluation, 14 of 15 (93.3%) tumors demonstrated complete necrosis. MWA is a safe, effective treatment modality; larger studies are warranted to demonstrate long-term oncologic outcomes.

Outcomes of transjugular intrahepatic portosystemic shunts for ascites

Refractory ascites represents a devastating complication of portal hypertension. Transjugular intrahepatic portosystemic shunt (TIPS) is an efficacious option for patients for whom transplant is not an immediate option. Techniques to optimize the hepatic venous pressure gradient and the use of covered stents have reduced rates of hepatic encephalopathy and stent occlusion, respectively. Patients with a Model for End-Stage Liver Disease score less than 15, serum creatinine less than 2 mg/dL, and serum bilirubin less than 2 mg/dL are particularly suited for TIPS placement. TIPS is also effective for hepatic hydrothorax and for massive ascites in the posttransplant setting, although future investigations are necessary to elucidate risk factors and establish the effect on transplant-free survival.

Portal vein embolization before right hepatectomy or extended right hepatectomy using sodium tetradecyl sulfate foam: technique and initial results

PURPOSE

To evaluate the safety and efficacy of portal vein embolization (PVE) with sodium tetradecyl sulfate (STS) foam.

MATERIALS AND METHODS

A single-center retrospective review of 35 patients (27 men and 8 women; mean age, 61 y) who underwent PVE with STS foam was performed. The technical success rate, rate of PVE at producing adequate future liver remnant (FLR) hypertrophy, and rate of disease progression precluding resection after PVE were analyzed. Complications of PVE and liver resection after PVE were recorded.

RESULTS

PVE was performed on 35 patients before right hepatic resection for both primary and secondary hepatic malignancies (22 hepatocellular carcinoma, 10 metastasis, 2 cholangiocarcinoma, 1 invasive gallbladder carcinoma). Technical success was achieved in 97.1% (34 of 35) of patients. Mean FLR of the total estimated liver volume increased from 24.5% (SD, 7.7%) to 36.5% (SD, 14.5%), a mean percentage increase of 48.8% (SD, 34.3%). PVE produced adequate FLR hypertrophy in 31 of 35 patients (88.6%). Proposed right hepatectomy was subsequently performed in 27 patients (77.1%). One patient remains scheduled for surgery, two had peritoneal spread at surgery and resection was aborted, two had disease progression on imaging after PVE, and three had inadequate FLR hypertrophy with no surgery. One major complication was observed related to PVE that involved nontarget embolization to segment III, which was managed conservatively.

CONCLUSIONS

Preoperative PVE with STS foam is a safe and effective method to induce hypertrophy of the FLR.

Preoperative inferior mesenteric artery embolization before endovascular aneurysm repair: decreased incidence of type II endoleak and aneurysm sac enlargement with 24-month follow-up

PURPOSE

To review the effect of preoperative embolization of the inferior mesenteric artery (IMA) before endovascular aneurysm repair (EVAR) on subsequent endoleaks and aneurysm growth.

MATERIALS AND METHODS

Between August 2002 and May 2010, 108 patients underwent IMA embolization before EVAR. Coil embolization was performed in all patients in whom the IMA was successfully visualized and accessed during preoperative conventional angiography. In this cohort, the incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and repeat intervention were compared with a group of 158 consecutive patients with a patent IMA on preoperative computed tomography angiography but not on conventional angiography, who therefore did not undergo preoperative embolization.

RESULTS

The incidence of type II endoleak was significantly higher in patients not treated with embolization (49.4% [78 of 158] vs 34.3% [37 of 108]; P = .015). The incidence of secondary intervention for type II endoleak embolization was also significantly higher in those who did not undergo embolization (7.6% [12 of 158] vs 0.9% [one of 108]; P = .013). At 24 months, an increase in aneurysm sac volume was observed in 47% of patients in the nonembolized cohort (21 of 45), compared with 26% of patients in the embolized cohort (13 of 51; P = .03). No aneurysm ruptures or aneurysm-related deaths were observed in either group. One patient in the embolization group developed mesenteric ischemia and ultimately died.

CONCLUSIONS

Preoperative embolization of the IMA was associated with reduced incidences of type II endoleak, aneurysm sac volume enlargement at 24 months, and secondary intervention.

Single-center experience with elective transcatheter coil embolization of splenic artery aneurysms: technique and midterm follow-up

PURPOSE

To review a single-center experience with elective coil embolization of splenic artery aneurysm (SAA) and analyze efficacy of the technique at midterm follow-up.

MATERIALS AND METHODS

From 2002 through 2011, 50 patients (28 women, 22 men; age range, 24-89 y; mean age, 53.5 y ± 13.6) underwent transcatheter coil embolization for treatment of SAAs. Pseudoaneurysms and ruptured aneurysms were excluded. A total of 63 SAAs were treated (size, 13-97 mm; mean, 29 mm). Ninety-eight percent of aneurysms were treated with coils alone. Regular follow-up consisted of an office visit and imaging. Patient medical records were reviewed for aneurysm location, procedural approach, and technical and clinical outcomes.

RESULTS

Ninety-eight percent of procedures were technically successful at thrombosing the aneurysm at the time of procedure. Repeat intervention was performed in four of 47 patients (9%) because of continued aneurysm perfusion at follow-up. Mean time to repeat intervention was 125 days (range, 42-245 d). All repeat interventions were technically successful. Neither aneurysm growth nor aneurysm rupture was observed in any patient during the follow-up period (mean, 78 weeks; range, 9 d to 7.1 y). There were no major adverse events. Major splenic infarction occurred in three of 33 patients (9%) with no underlying liver disease and normal splenic volume and in seven of 14 patients (50%) with portal hypertension.

CONCLUSIONS

Percutaneous transcatheter coil embolization is a safe, effective, and minimally invasive treatment for SAAs as evidenced by high rates of technical success and freedom from aneurysm rupture.

Emergent embolization of arterial bleeding after vacuum-assisted breast biopsy

Vacuum-assisted core breast biopsy has become important in evaluating patients with suspicious breast lesions. It has proven to be a relatively safe procedure that in rare cases can result in vascular complications. These are the first reported cases of transcatheter embolization of uncontrolled breast hemorrhage after vacuum-assisted breast biopsy. With increased use of biopsy and larger-gauge devices, breast imaging groups may consider embolotherapy as a safe alternative for treatment of hemorrhage in a select group of patients.