Chemoembolization Beyond Hepatocellular Carcinoma: What Tumors Can We Treat and When?

Liver metastases are the most common malignancy found in the liver and are 20 to 40 times more common than primary hepatic tumors, including hepatocellular carcinoma. Patients with liver metastases often present with advanced disease and are not eligible for curative-intent surgery or ablative techniques. The unique hepatic arterial blood supply of liver metastases allows interventional radiologists to target these tumors with transarterial therapies. Transarterial chemoembolization (TACE) has been studied in the treatment of liver metastases originating from a variety of primary malignancies and has demonstrated benefits in terms of hepatic progression-free survival, overall survival, and symptomatic relief, among other benefits. Depending on the primary tumor from which they originate, liver metastases may have different indications for TACE, may utilize different TACE regimens and techniques, and may result in different post-procedural outcomes. This review offers an overview of TACE techniques and specific considerations in the treatment of liver metastases, provides an in-depth review of TACE in the treatment of liver metastases originating from colorectal cancer, neuroendocrine tumor, and uveal melanoma, which represent some of the many tumors beyond hepatocellular carcinoma that can be treated by TACE, and summarizes data regarding when one should consider TACE in their treatment algorithms.

A 5-Year Update on the IR Residency Match: 2022 National Survey Results of Program Directors and Matched Applicants Compared with 2017.

PURPOSE: To characterize the experiences of matched applicants (MAs) and program directors (PDs) in the 2022 interventional radiology (IR) residency Match and compare with 2017 data. METHODS: Surveys were distributed to IR PDs and MAs from the 2022 Match. Findings were compared with those of 2017 using the 2-sample t test and Fisher exact test. RESULTS: In total, 68 MAs (40%) and 47 PDs (52%) responded. Collected demographic traits were similar, including ongoing male predominance (77% of MAs, 83% of PDs). Moreover, 86% of MAs and 87% of PDs were "satisfied" with Match outcomes. Compared with those in 2017, MAs applied to more IR programs (P < .001). MAs reported more research (P = .003) and abstracts/publications (P < .001) and ranked these as more important than PDs did (P < .001 for both). Approximately 82% of PDs gave special attention to candidates who completed a visiting rotation at their institution; 60% of MAs and 95% of PDs believed virtual interviews resulted in overinterviewing (P < .001); both agreed they provided convenience and accessibility. Furthermore, 63% of MAs believed a Step 1 pass/fail system will be less equitable for applicants. Additional data on demographics, medical school experiences, applications, interviews, intern year, and rank process were reported. CONCLUSIONS: Satisfaction with Match results remained high from 2017 to 2022, although efforts are needed to improve applicants' ability to navigate the application process, address overapplying, and evaluate concerns regarding the Step 1 pass/fail system. These survey findings will help inform applicants and PDs for future match cycles.

Comparison of Transthoracic Contrast Echocardiography with High-Resolution Chest CT after Embolization of Pulmonary Arteriovenous Malformation.

PURPOSE: To compare postembolotherapy follow-up graded transthoracic contrast echocardiography (TTCE) and high-resolution computed tomography (CT) of the chest and to evaluate the use of graded TTCE in the early postembolic period. MATERIALS AND METHODS: Thirty-five patients (6 men and 29 women; mean age, 56 years; range, 27-78 years) presenting for postembolotherapy follow-up between 2017 and 2021 with concurrent high-resolution CT and graded TTCE were analyzed retrospectively. Untreated pulmonary arteriovenous malformations (PAVMs) with a feeding artery of ≥2 mm were considered treatable. RESULTS: Ninety-four percent of patients (33 of 35) did not have treatable PAVMs on high-resolution CT. TTCE was negative for shunts (Grade 0) in 34% of patients (n = 12). Of patients with a TTCE positive for shunts (23 of 35, 66%), 83% had a Grade 1 shunt, 13% had a Grade 2 shunt, and 4% had a Grade 3 shunt. No patient with a Grade 0 or 1 shunt had a treatable PAVM on high-resolution CT. Of the 2 patients with PAVMs requiring treatment, one had a Grade 2 shunt and one had a Grade 3 shunt. TTCE grade was significantly associated with the presence of a treatable PAVM on high-resolution CT (P < .01). CONCLUSIONS: Graded TTCE predicts the need for repeat embolotherapy and does so reliably in the early postembolotherapy period. This suggests that graded TTCE can be utilized in the postembolotherapy period for surveillance, which has the potential to lead to a decrease in cumulative radiation in this patient population.

Choosing the right treatment for the right lesion, part I: a narrative review of the role of plain balloon angioplasty in dialysis access maintenance.

Background and Objective: The majority of patients with end-stage renal disease (ESRD) requiring hemodialysis (HD) do so via an arteriovenous fistula (AVF) or graft. Both of these accesses are complicated by dysfunction related to neointimal hyperplasia (NIH) and subsequent stenosis. Percutaneous balloon angioplasty using plain balloons is the first line treatment for clinically-significant stenosis, with excellent initial response rates, however, with poor long-term patency and need for frequent reintervention. Recent research has sought to improve patency rates utilizing antiproliferative drug-coated balloons (DCBs), however, their role in treatment has not yet been fully determined. In part one of this two-part review, we aim to provide a comprehensive overview of the mechanisms of arteriovenous (AV) access stenosis, the evidence behind their treatment with high-quality plain balloon angioplasty techniques, and treatment considerations for specific stenotic lesions. Methods: An electronic search was performed on PubMed and EMBASE to identify relevant articles from 1980 to 2022. The highest available level of evidence regarding stenosis pathophysiology, angioplasty techniques, and approaches to treating different types of lesions within fistulas and grafts were included as part of this narrative review. Key Content and Findings: NIH, and subsequent stenoses, develop via a combination of upstream events, causing vascular damage, and downstream events, representing the subsequent biologic response. The large majority of stenotic lesions can be treated utilizing high-pressure balloon angioplasty, with the addition of ultra-high pressure balloon (UHPB) angioplasty for resistant lesions and prolonged angioplasty with progressive balloon upsizing for elastic lesions. Additional treatment considerations must be taken into account when treating specific lesions, including cephalic arch and swing point stenoses in fistulas and graft-vein anastomotic stenoses in grafts, amongst others. Conclusions: High-quality plain balloon angioplasty, performed utilizing the available evidence-basis regarding technique and considerations for specific lesion locations, is successful in treating the large majority of AV access stenoses. While initially successful, patency rates remain non-durable. Part two of this review will discuss the evolving role of DCBs, which seek to improve angioplasty outcomes.

Choosing the right treatment for the right lesion, Part II: a narrative review of drug-coated balloon angioplasty and its evolving role in dialysis access maintenance.

Background and Objective: Drug-coated balloons (DCBs) seek to inhibit restenosis in treated hemodialysis access lesions by delivering an anti-proliferative agent (paclitaxel) into the vessel wall. While DCBs have proven effective in the coronary and peripheral arterial vasculature, the evidence for their use in arteriovenous (AV) access has been less robust. In part two of this review, a comprehensive overview of DCB mechanisms, implementation, and design is provided, followed by an examination of the evidence basis for their use in AV access stenosis. Methods: An electronic search was performed on PubMed and EMBASE to identify relevant randomized controlled trials (RCTs) comparing DCBs and plain balloon angioplasty from January 1, 2010 to June 30, 2022 published in English. As part of this narrative review, a review of DCB mechanisms of action, implementation, and design is provided, followed by a review of available RCTs and other studies. Key Content and Findings: Numerous DCBs have been developed, each with unique properties, although the degree to which these differences impact clinical outcomes is unclear. Target lesion preparation, achieved by pre-dilation, and balloon inflation time have proven important factors in achieving optimal DCB treatment. Numerous RCTs have been performed, but have suffered from significant heterogeneity, and have often reported contrasting clinical results, making it difficult to draw conclusions on how to implement DCBs in daily practice. On the whole, it is likely there is a population of patients who benefit from DCB use, but it is unclear which patients benefit most and what device, technical, and procedural factors lead to optimal outcomes. Importantly, DCBs use appears safe in the end-stage renal disease (ESRD) population. Conclusions: DCB implementation has been tempered by the lack of clear signal regarding the benefits of DCB use. As further evidence is obtained, it is possible that a precision-based approach to DCBs may shed light onto which patients will truly benefit from DCBs. Until that time, the evidence reviewed herein may serve to guide interventionalists in their decision making, knowing that DCBs appear safe when used in AV access and may provide some benefit in certain patients.

Techniques in adrenal vein sampling: Multipurpose catheter shape facilitates sampling of cranially oriented right adrenal veins.

Adrenal vein sampling (AVS) failure is often attributed to difficulty sampling the right adrenal vein (RAV). Normally, the RAV is caudally oriented, however, cranial orientation of the RAV is not uncommon. In such cases, use of a multipurpose (MPA) catheter shape may facilitate sampling. Between 2014 and 2019, 351 patients underwent AVS and RAV sampling with an MPA catheter occurred in 23 patients (7%, 10M:13F). Data regarding pre-AVS imaging, procedural details, and AVS results were collected, the RAV vertical angle was measured on venography using the IVC right lateral wall as the craniocaudal axis (0° defined as caudal, 180° cranial), and correlation of the number of catheters used until successful sampling with the MPA catheter and various procedural measures was assessed. Twenty-four technically successfully AVS were performed in 23 patients, all of whom had cranially oriented RAVs on intra-procedural venography. An MPA catheter was the first choice in 2 patients with previously known cranially oriented RAVs. In the remaining patients, the MPA catheter was 2nd choice in 21% (n = 5), 3rd choice in 50% (n = 12), and up to 8th choice (n=1). Early utilization of the MPA catheter correlated with lower fluoroscopic time (R = 0.71, P = 0.0001) and lower contrast volume (R = 0.77, P < 0.0001). These results support the use of the MPA catheter when sampling cranially oriented RAVs. MPA catheters should be readily considered when cranially oriented RAVs are present and when caudally-oriented catheters fail to identify the RAV.

"Double-Down" Adrenal Vein Sampling Results in Patients with Apparent Bilateral Aldosterone Suppression: Utility of Repeat Sampling including Super-Selective Sampling.

PURPOSE: To report outcomes of patients undergoing adrenal vein sampling (AVS) for primary aldosteronism with results indicating apparent bilateral adrenal suppression (ABAS), in which the adrenal aldosterone-to-cortisol ratios are decreased bilaterally ("double-down") compared to the non-adrenal sample, and evaluate repeat AVS results. MATERIALS AND METHODS: Between 2003 and 2020, 762 patients underwent AVS. Twenty patients (2.6%; male, 12; female, 8; age 50.3 ± 9.7 years) with ABAS on initial AVS were identified. Ten underwent repeat AVS. Super-selective AVS (SS-AVS) was employed in 6 of 10 repeat AVS (60%). Outcomes after AVS were analyzed. A lateralization index (LI) >4 was considered an indication for adrenalectomy. RESULTS: Repeat AVS was diagnostic in 70% of patients (n = 7), with 6 of 7 lateralizing with LI >4 (median LI = 32.3; range 4.6-54.8) and 1 of 7 nearly lateralizing (LI = 3.5). All 7 patients underwent adrenalectomy. ABAS was redemonstrated in 3 patients (30%): 2 with unilateral adenomas on cross-sectional imaging underwent adrenalectomy despite ABAS results and 1 was lost to follow-up. Four of 6 patients (66%) who underwent SS-AVS were diagnosed with unilateral disease (median LI = 43.3; range 23.9-54.8), with one patient's diagnosis reliant upon a single super-selective sample. In total, 9 patients underwent adrenalectomy after repeat AVS, all of whom had improved blood pressure control postoperatively. Ten patients did not undergo repeat AVS: 6 were lost to follow-up, 3 underwent medical management, and 1 underwent adrenalectomy. CONCLUSIONS: AVS should be repeated when "double-down" ABAS results are encountered. Super-selective sampling may provide worthwhile diagnostic data when employed during repeat AVS.

Infectious Recidivism in Tunneled Dialysis Catheters Removed for Bloodstream Infection in the Intensive Care Unit.

PURPOSE: To determine the rate of recurrent infection of ICU patients who underwent tunneled dialysis catheter (TDC) exchange or removal for bloodstream infection. MATERIALS AND METHODS: Forty seven patients, with a total of 61 TDCs removed for bloodstream infection while admitted in an ICU from 2017-2020, were identified. TDCs were exchanged over a wire or removed and replaced. Thirteen patients (21%) were managed with non-tunneled dialysis catheters (NTDCs) until delayed TDC replacement at ICU departure. Forty seven TDCs were removed for bacteremia (77%), 13 for fungemia (21%), and 1 for both (2%). Thirty TDCs (49%) were exchanged over-the-wire (ICU-exchanged TDCs), and 31 (51%) were removed. Of the patients who underwent TDC removal, 9 had a new TDC placed while still admitted in the ICU (ICU-replaced TDCs), and 7 underwent delayed TDC replacement at ICU departure. Data regarding infection, removal technique, catheter replacement, and patient outcomes were analyzed. RESULTS: There were 10 instances of recurrent bloodstream infection (infectious recidivism), occurring in 7 ICU-exchanged TDCs (7/30, 23%) and 3 ICU-replaced TDCs (3/9, 33%). Bloodstream infection complicated 22% of NTDCs used in patients undergoing delayed TDC replacement. No cases of TDC infectious recidivism were observed in patients who underwent delayed TDC replacement (0/7, 0%) after ICU departure. CONCLUSIONS: High rates of infectious recidivism exist in the ICU, meriting further investigation into how to optimally manage these patients. In those in whom TDCs are removed, withholding TDC replacement until ICU departure may help to minimize the rate of recurrent infection.

Medical Student Education During the COVID-19 Pandemic: Initial Experiences Implementing a Virtual Interventional Radiology Elective Course.

RATIONALE AND OBJECTIVES: In response to the COVID-19 pandemic reducing medical student presence on clinical services and in classrooms, academic institutions are utilizing a virtual format to continue medical student education. We describe a successful initial experience implementing a virtual elective in interventional radiology (IR) and provide the course framework, student feedback, and potential improvements. MATERIALS AND METHODS: A 2-week virtual IR elective curriculum was created utilizing a combination of synchronous and asynchronous learning and the "flipped" classroom educational model. Students virtually participated in daily IR resident education conferences, resident-led case review sessions, and dedicated lectures. Asynchronous prelearning material consisted of text and video correlating to lecture topics. Anonymous precourse and postcourse surveys were sent to all participating students (n = 10). RESULTS: Ten students (100%) completed precourse and seven (70%) completed postcourse surveys. Enrolled students were considering residencies in surgery (50%), internal medicine (40%), interventional radiology (30%), and/or diagnostic radiology (30%). Students' understanding of what IRs do and the procedures they perform (p < 0.001), when to consult IR for assistance in patient management (p = 0.005), and the number of IR procedures students could recall (p = 0.015) improved after the course. Case-review sessions and virtual lectures ranked as having the highest education value. Students recommended additional small-group case workshops. CONCLUSION: This successful virtual IR elective provides a framework for others to continue IR medical student education during the pandemic and grow the specialty's presence within an increasingly virtual medical school curriculum. The described model may be modified to improve IR education beyond the COVID-19 era.

Endovascular Treatment of an Anatomically Complex Iliac Lesion and a Review of Variant Iliac Venous Anatomy.

The diagnosis and treatment of pelvic venous disease is complicated by a number of potential venous anatomic variants. Stent-assisted recanalization of a chronically occluded left external iliac vein draining directly into the inferior vena cava, with absence of the left common iliac vein, is described here. Variant iliac venous anatomy is reviewed in 3 categories: additional iliac vessels, absence/shortening of iliac vessels, and deviations in the drainage pattern of iliac vessels. Additionally, variations of the ascending lumbar and iliolumbar veins, the identification of which can aid in the treatment of pelvic venous disease, are described.

Postembolotherapy Pulmonary Arteriovenous Malformation Follow-Up: A Role for Graded Transthoracic Contrast Echocardiography Prior to High-Resolution Chest CT Scan.

BACKGROUND: High-resolution chest CT (HRCT) scan is recommended after pulmonary arteriovenous malformation (PAVM) embolotherapy to assess for PAVM persistence and untreated PAVM growth. Graded transthoracic contrast echocardiography (TTCE) predicts the need for embolotherapy in PAVM screening. This study sought to determine whether postembolotherapy graded TTCE can similarly predict the need for repeat embolotherapy. METHODS: Thirty-two patients (8 men and 24 women; mean age, 51.1 ± 12.6 years) with prior PAVM embolotherapy and follow-up HRCT scan were prospectively enrolled. Patients underwent graded TTCE using a validated three-point quantitative grading scale. TTCE grade and HRCT findings were compared. RESULTS: Median time between most recent HRCT scan and TTCE was 7 days (interquartile range, 0-272 days). Thirty patients (94%) had no PAVMs requiring repeat embolotherapy on HRCT scan. Two patients (6%) had PAVMs requiring repeat embolotherapy (feeding artery [FA] ≥ 3 mm), one with untreated PAVM growth and one with treated PAVM persistence. TTCE was positive in 88% of patients (n = 28). All patients (n = 4, 12%) with negative TTCE had no visible PAVMs on HRCT scan. Nine patients (32%) had grade 1 shunt, 10 (35%) had grade 2 shunt, and nine (32%) had grade 3 shunt. No patients with grade 1 shunt had PAVMs amenable to repeat embolotherapy on HRCT scan. All patients (n = 2) with PAVMs requiring repeat embolotherapy (FA ≥ 3 mm) had grade 3 shunt. TTCE grade was significantly associated with PAVM FA diameter (P < .001). CONCLUSIONS: Postembolotherapy graded TTCE can predict the need for repeat embolotherapy on HRCT scan. Patients with negative TTCE and grade 1 shunt may not require HRCT follow-up and can potentially be followed with serial graded TTCE. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT02936349; URL: www.clinicaltrials.gov.

The 2017 Integrated IR Residency Match: Results of a National Survey of Applicants and Program Directors.

PURPOSE: To characterize and compare the experiences of matched applicants and program directors (PDs) participating in the first large-scale integrated interventional radiology (IR) residency match. MATERIALS AND METHODS: Survey questionnaires were distributed nationally to integrated IR applicants who matched in the 2017 Match cycle and PDs. Both groups were questioned regarding their experiences with the application, interview, rank, and match processes as well as applicant-specific and PD-specific information. Summary and descriptive statistics were applied to responses, and comparison of Likert scale responses was performed by two-sample t test. RESULTS: Sixty-one matched applicants (51.3%) and 34 PDs (55.7%) responded to the survey. Regarding the match process, applicants believed United States Medical Licensing Examination (USMLE) Step 1 score (P = .002) and connection to a program's geographic location (P = .006) were significantly more important than PDs did, whereas PDs ranked grades (P = .049), class rank (P = .011), academic awards (P = .003), additional degrees (P < .001), and USMLE Step 2 Clinical Skills score (P < .001) as significantly more important factors than applicants did. Additional information regarding demographic data, medical school experiences in IR, application strategies, interview experiences, rank lists, the intern year, and match results are reported. CONCLUSIONS: The completion of the first large-scale integrated IR match represents a paradigm shift in the way in which IR practitioners are recruited and trained. This study provides valuable benchmark data and analysis that can be used to improve efforts to match the best-fitting applicants into the integrated IR residency and improve future match cycles for applicants and PDs alike.

Increasing Medical Student Exposure to IR through Integration of IR into the Gross Anatomy Course.

PURPOSE: To compare medical student knowledge of and interest in interventional radiology (IR) before and after the integration of an IR lecture series within the gross anatomy course. MATERIALS AND METHODS: Four elective IR lectures were scheduled to coincide with the relevant anatomy dissection curriculum. Anonymous surveys were distributed to 146 students before and after the lectures regarding students' knowledge of and interest in IR, responsibilities of an IR physician, and IR training pathways. Those who did not attend served as controls. RESULTS: Response rates were 67% (n = 98) in the prelecture group, 55% (n = 22) in the group who attended the lecture, and 28% (n = 30) in the control group. A total of 73% of the prelecture group reported little knowledge of IR compared with other specialties. This decreased to 27% in those who attended the lecture (P < .001). A total of 32% of those who attended believed they had more knowledge of IR than any other specialty, compared with 7% of controls (P value not significant) and 2% of the prelecture group (P < .001). Those in attendance could name a significantly greater number of IR procedures (mean, 1.82) than the prelecture group (mean, 0.57; P < .001). A total of 64% of those who attended would consider a career in IR, compared with 24% in the prelecture group and 33% in the control group (P < .05). A total of 68% of those who attended had knowledge of the IR residency, compared with 5% in the prelecture group and 33% in the control group (P < .05). CONCLUSIONS: Integration of IR education into the gross anatomy course proved to be a highly effective way of teaching preclinical students about IR and generating interest in the field.

Long-term outcomes of a benign biliary stricture protocol.

PURPOSE: To evaluate long-term outcomes of a structured protocol for percutaneous treatment of benign biliary stricture. MATERIALS AND METHODS: Seventy-one patients (37 men, 34 women; mean age, 54 y; age range, 23-84 y) entered the protocol, which consisted of staged upsizing of internal/external biliary catheters, balloon dilation (nominally 8 mm), and prolonged stent treatment (6 mo) at maximal catheter size (nominally 18 F). It concluded with a capping trial and catheter removal if the stricture remained patent. Fifty-three patients completed the protocol and 18 did not (6 died, 6 underwent alternative treatment, 4 were lost to follow-up, and 2 underwent repeat transplantation). Stricture features, treatment parameters, complications, and outcomes were reviewed, and Kaplan-Meier analysis was conducted. RESULTS: Strictures were anastomotic in 45 patients (64%), intrahepatic in 14 (20%), extrahepatic in 7 (10%), and multiple (intra- and extrahepatic) in 5 (7%). A right-sided approach was used in 47 patients (66%) patients, a left-sided approach in 18 (25%), and a bilateral approach in 6 (9%). Forty-six patients who entered the protocol (65%) and 46 patients who completed the protocol (87%) showed stricture patency. Four of 7 patients in whom a capping trial failed underwent surgical revision, 2 required chronic biliary drainage, and 1 received a metal stent. Follow-up (range, 0-12 y; mean, 4.7 y) was obtained for 42 of 53 patients who completed the protocol (79%). Kaplan-Meier analysis showed stricture patency probabilities of 84% at 1 year after treatment, 78% at 2 years, 74% at 5 years, and 67% at 10 years. CONCLUSIONS: Use of a structured protocol for the percutaneous treatment of benign biliary strictures yields durable long-term results, suggesting that percutaneous treatment is an effective therapy.