GLASS Classification Correlates with Primary Patency in Chronic Limb-Threatening Ischemia Patients Treated Endovascularly

Primary Limb-Based Patency for Chronic Limb-Threatening Ischemia Treated with Endovascular Therapy Based on the Global Limb Anatomic Staging System

Clinical question

In a large population and with long follow-ups, does the GLASS classification correlate with primary patency in patients with chronic limb-threatening ischemia who underwent endovascular therapy? And what were the risk factors for primary patency loss?

Take away point

GLASS classification may be an indicator of prognosis after intervention in patients with chronic limb-threatening ischemia.

Reference

Peng M, Li C, Nie C, Chen J, Tan J. Primary Limb-Based Patency for Chronic Limb-Threatening Ischemia Treated with Endovascular Therapy Based on the Global Limb Anatomic Staging System. J Vasc Interv Radiol. 2024 Jul 24:S1051-0443(24)00472-X. doi: 10.1016/j.jvir.2024.07.015. Epub ahead of print. PMID: 39059464.

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Study design

Retrospective, observational, descriptive study

Funding Source

N/A

Setting

Chongqing University Three Gorges Hospital, Wanzhou, Chongqing, China (academic institution)

Figure

Kaplan-Meier curves for primary limb-based patency stratified by Global Limb Anatomic Staging System (GLASS) stage for limbs with chronic limb-threatening ischemia undergoing endovascular therapy. (a) At 1 year after intervention: GLASS Stage I versus II, 78.8% versus 69.5%; P = .232; GLASS Stage I versus III, 78.8% versus 41.6%; P < .001; GLASS Stage II versus III, 69.5% versus 41.6%; P = .001. (b) At the end of follow-up: GLASS Stage I versus II, 54.2% versus 38.6%; P = .042; GLASS Stage I versus III, 54.2% versus 10.5%; P < .001; GLASS Stage II versus III, 38.6% versus 10.5%; P < .001. G = grade; HR = hazard ratio.

Summary

The Global Limb Anatomic Staging System (GLASS) classification system, proposed in 2019, aims to standardize the assessment of limb anatomy in patients with critical limb threatening ischemia (CLTI) in order to guide treatment decisions. It consists of three stages, with Stage III representing the highest severity of disease. Prior studies were inconclusive regarding the ability of GLASS to predict limb-based patency. This study was conducted in order to assess the potential of the GLASS classification system to predict prognostic outcomes of patients with CLTI who underwent endovascular therapy with a larger patient population and longer follow-up.

Using a retrospective analysis, the investigators reviewed data from a total of 1,029 patients who underwent revascularization therapy for CLTI between January 1, 2018 and May 31, 2022 at the Chongqing University Three Gorges Hospital. After excluding patients with confounding variables, 231 patients (236 limbs) were included in the final analysis. The GLASS classification of the ischemic limbs was assessed using CTA or digital subtraction angiography prior to intervention. Of these patients, 52 (22%) were classified as GLASS Stage I, 59 (25%) were classified as GLASS Stage II, and 125 (53%) were classified as GLASS Stage III. Patients were followed up at 1-, 3-, 6-, and 12-months post-intervention and annually thereafter. Patient interviews, physical examinations, and vascular ultrasonography were used to assess patency at follow up.

The mean patient age was 74.45 years, with a predominance of male patients (76.7%). Notably, 36.9% of limbs were classified as clinical Stage IV according to the WIfI system, and common comorbidities included hypertension (64.8%) and diabetes (41.1%). For procedural details, 23.3% of limbs received no stents, while 58.1% were treated with bare nitinol stents. There were significant differences in the number of stents used across GLASS stages (P < .001) and in postoperative antithrombotic regimens (P = .004), but not in the type of stents used (P = 0.101). The median follow-up time was 1,279 days, with primary limb-based patency rates declining significantly with higher GLASS stages; for example, 1-year limb-based patency rates were 78.8% for Stage I and 41.6% for Stage III (P < .001). Univariate analysis identified GLASS stage III, diabetes, and smoking as independent risk factors for long-term patency loss, while male sex was associated with a lower risk. Multivariate analysis confirmed all these to be independent factors associated with limb-based patency.

The authors cited multiple prior studies that found evidence that the use of GLASS staging can predict limb-based patency rates in CLTI patients undergoing endovascular treatment. This study, which had a larger sample size and longer follow-up times than those cited, supports these findings and provides additional insight.

Commentary

The results from this study, along with those referenced within it, provide a strong argument for using the GLASS staging criteria as a prognostic tool for patients with CLTI undergoing endovascular treatment. Systems like GLASS are important for personalized procedural strategy, post-procedural medical management, and follow-up schedule, and the questions addressed in this study contribute to holistic approaches around patients with CLTI.

While the study's methodology was robust with a large patient population and long follow-up, further evaluation of endovascular strategies (specific types of stents and balloons, as well as potential changes of certain strategies during the study period, i.e. paclitaxel-coated devices), antiplatelet/antithrombotic strategies (especially given statistically significant differences in antithrombotic medications post-procedural), and patient-relevant quality-of-life outcome measures will provide further insights to the endovascular community. Additionally, some patient groups were excluded from the analysis; one in particular was the group with hepatocyte growth factor therapy involved. Offering clear explanations for each exclusion would strengthen the validity of the findings by demonstrating how these decisions improved the overall rigor of the study.

The discussion of confounding variables raises an important consideration: should GLASS staging criteria incorporate some of these factors? Perhaps a scoring system, rather than a purely staging-based approach, would offer physicians a more comprehensive tool for making informed treatment decisions. At the minimal, the study can benefit from a discussion on the impact of the study’s results in daily clinical practice. Should patients with higher GLASS staging criteria receive more aggressive antithrombotic regimen or more frequent clinical follow-up for potential repeat revascularization? Or was there a cost-effective time point at which procedural intervention should be discouraged? Ultimately, this paper addresses a scientific question methodically but leaves room for future research regarding the practical aspects.

Post Author
Isabel Okinedo, BA
UMass Chan Medical School
@isabelokinedo

Eye90 Beads Provide Safe and Effective Direct Visualization in Radioembolization

Imageable Radioembolization Microspheres for Treatment of Unresectable Hepatocellular Carcinoma: Interim Results from a First-in-Human Trial

Clinical question 

Can radiopaque yttrium-90 microspheres safely and effectively treat unresectable hepatocellular carcinoma while providing real-time visibility of treatment?

Take away point 

Eye90, a radiopaque Y90 microsphere, enables real-time evaluation and treatment adjustment during radioembolization, potentially improving tumor targeting and serving as a tumor response biomarker. Initial study showed 50% complete response at 3 months with no severe adverse events.

Reference 

Abraham, R.J., Arepally, A., Liu, D., Lewandowski, R., Kappadath, S.C., Verma, A., Dobrowski, D. and Holden, A., 2024. Imageable Radioembolization Microspheres for Treatment of Unresectable Hepatocellular Carcinoma: Interim Results from a First-in-Human Trial. Journal of Vascular and Interventional Radiology, 35(10), pp.1464-1473.

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Study design 

Prospective, observational, descriptive study

Funding Source 

ABK Biomedical

Setting 

Auckland City Hospital, Auckland, New Zealand

Figure

A 53-year-old man with chronic hepatitis B. Axial contrast-enhanced computed tomography (CT) (arterial phase) demonstrated a 4.3-cm Segment 8 hepatocellular carcinoma (white arrow) adjacent to previous transarterial chemo- embolization scar (white arrowhead). CT image demonstrating radiopaque Eye90 microsphere distribution in hepatocellular carcinoma (arrow) and surrounding treated liver volume.

Summary

Current 90Y microspheres have limitations. Glass microspheres lack flexibility in quantity and activity customization, often necessitating multiple vials and kits for larger volumes. Resin 90Y provides quantity and activity customization, but at the cost of increased burden on nuclear medicine labs and operator risk. Both microspheres also have limitations in visibility, requiring post-treatment SPECT/ PET for assessing 90Y distribution, tumor targeting, and dosimetry.

Addressing these challenges, Eye90 Microspheres introduces radiopaque properties for direct CT visualization with a customizable dose with radioactivity between 0.4-9.6 GBq at 3 preset mass ranges: (a) small (100–200 mg), (b)medium (201–400 mg), and (c) large (401–600 mg). Personalized dose vial quantity and activity is determined using a 3-compartment partition model that considers various patient-specific factors based on the technetium-99m macro- aggregated albumin SPECT/CT. This personalized approach reportedly eliminates the need for dose-draw or multiple vials.

Accompanying the Eye90 Microspheres is the Eye90 delivery device, which utilizes a dual-syringe system to achieve a controlled uniform delivery concentration of 60 mg/mL. The delivery device also allows the users to pause, assess microcatheter location with contrast media, examine microsphere distribution using CT modalities, and resume administration as needed.

This study reports 6-month safety, effectiveness, and imageability results for Eye90 in 6 subjects with unresectable HCC (median size of 3.1 cm, range: 1.2 – 4.3 cm). Subjects underwent planning procedure (90Y mapping) followed by selective treatment (≤2 segments) using partition dosimetry by SurePlan LiverY90 aiming to deliver at least 205 Gy and preferably > 250 Gy to the tumor. Post-therapy SPECT/CT, unenhanced lung CT, and 4-phase liver CT within 24 hours of treatment were obtained to correlate microsphere radiopacity with radioactivity. Follow-up were scheduled on days 21, 42, 90, and 180 after treatment.

Post-treatment SPECT/CT demonstrated mean and median dose of 283 Gy and 132 Gy to the tumor, respectively. Microsphere density within the tumor was calculated at 26,988 per mL. All subjects reported adverse events, but no treatment-related Grade ≥3 AEs occurred. At 90 days, 50% achieved complete response (CR) and 33.3% partial response (PR). At 180 days, 50% maintained CR and 16.7% PR. The other patient with PR, and the patient with stable disease at 90 days, underwent TACE and could not be evaluated. Qualitative analysis showed agreement between microsphere radiopacity on CT and radioactivity on SPECT/CT, with CT revealing heterogeneous dose distribution, and absence of radiopacity in the region of a particular tumor despite SPECT/CT activity noted throughout this region. This particular tumor did not respond to treatment.

Commentary 

Eye90 Microspheres represent another advancement in transarterial radioembolization, offering direct visualization of microsphere and tumor targeting on CT modalities. This capability could lead to more precise treatment execution, real-time therapy adjustments, and potentially serve as a biomarker for predicting tumor response and a foundation for more accurate dose-response relationships. The dual-syringe administration system allows for customized quantity and activity of microspheres, enhancing treatment personalization.

While the initial results are promising, the small sample size, short follow-up period, lower-than-planned tumor doses, and mediocre treatment response necessitate further research. The ongoing U.S. Pivotal IDE Route90 trial will provide more comprehensive data on a larger cohort. If these results hold up in larger studies, Eye90 Microspheres could redefine the standard of care in HCC treatment. The potential for improved precision, personalization, and real-time assessment makes this a technology to watch closely in the coming years.

Post author
Leila Haghani, MD 

Research Fellow 

University of Massachusetts Chan Medical School
@dr_Leila_IRad

Paclitaxel Containing Devices in Femoropopliteal Arterial Disease: The Trees and the Forest

An Up To Date Meta-Analysis on Paclitaxel Containing Devices in Femoropopliteal Arterial Disease, And A Commentary On The Entirety of the Data to Date.

Clinical question

Is paclitaxel safe when used in drug eluting stents and drug coated balloons for revascularization of the femoropopliteal artery?

Take away point

Paclitaxel containing devices are safe and effective devices, especially in their current usage and at their current generation. Previous versions of the devices may have conveyed some mortality risk, but it’s important to understand both the meta-analyses and the individual studies that comprise the data reporting, and how clinical practice is nuanced and so does the literature..

Reference

Katsanos, K. (2024). Paclitaxel meta-analyses in the lower limbs: Missing the trees for the forest. Journal of Vascular and Interventional Radiology.
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Briody, H., Kearns, C. A., & Lee, M. J. (2024). Mortality, safety and efficacy of paclitaxel-containing balloons and stents in the femoropopliteal artery: systematic review and meta-analysis of randomized controlled trials since 2018. Journal of Vascular and Interventional Radiology. 

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Study design

Meta-analysis, commentary/perspective

Setting

Meta-analysis was performed at Beaumont Hospital, Dublin Ireland and the Royal College of Surgeons in Ireland.
Commentary is from University Hospital Patras, School of Medicine, Rio, Greece.

Figure

Summary

In revascularization efforts for peripheral arterial disease, paclitaxel has proven to be an excellent anti-restenotic agent in the femoropopliteal artery when used in drug coated balloons and drug eluting stents in multiple randomized controlled trials. While effective, its safety profile was called into question in a 2018 meta-analysis. The meta-analysis, published by Katsanos et al, found statistically significant increases in all-cause death in patients with paclitaxel coated devices, and urged further investigations. In 2023, a patient level, industry funded meta-analysis concluded there was no excess mortality. Based on this study, the FDA published their official statement that there is no discernible excess of mortality.

The current meta-analysis was performed to provide an independent analysis of safety and effectiveness outcomes, including but not limited to mortality. The literature search was performed from 2018 (a choice made so this study would act as an update of the aforementioned Katsanos study) and included 19 randomized controlled trials for a total of 4,284 participants. When selecting studies, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was utilized (see figure). Effectiveness outcomes were primary patency which was analyzed using risk ratios via inverse variance, random-effects model. Safety outcomes were all cause mortality, target limb amputation, target lesion revascularization, clinically driven target lesion revascularization, and thrombosis. These were also analyzed using risk ratios via inverse variance, random effects model, as well as heterogeneity assessment via visual inspection of forest plots, chi squared test and I^2 statistic.

The results found no evidence for all-cause mortality in paclitaxel containing devices in the femoropopliteal region from 12 to 60 months, nor did they find any other safety concerns. The study redemonstrated the effectiveness of paclitaxel devices in maintaining primary patency with a pooled risk ratio of 1.55. Taken together, this meta-analysis concluded that paclitaxel containing devices work, and are safe to use. They compare this study directly to the Katsanos study due to its similar methodology and design, however they offer no suggestions as to the source of the different findings.

In response to the multiple meta-analyses looking at the use of paclitaxel containing devices in the femoropopliteal arteries with no evidence of increased all-cause mortality, Dr. Konstantinos Katsonas provided a companion commentary. In the piece, he presents 27 studies from 2008-2021 which show an increase in all-cause mortality in the paclitaxel containing device arm, arguing that the recent studies demonstrate dilution of the mortality signal, but do not eradicate it completely. He presents a meta-regression of long-term risk ratio of all cause death against publication year and shows that the observed mortality risk decreases with publication year, which would seem to suggest earlier generation devices or clinical practices may be the cause for the mortality signal. He further subgroups the studies by paclitaxel dosage and shows that the relative mortality risks may be different among the different devices with variable paclitaxel dosing. He concludes that the reader must not miss the trees for the forest, meaning that the individual studies may have points of interest that become diluted in meta-analysis.

Commentary

The academic discussion around paclitaxel can make it difficult for providers to know if these devices are safe or not. This most recent meta-analysis is an excellent consolidation of the most recent literature on paclitaxel containing devices in femoropopliteal artery treatment. The results add to the body of evidence that these paclitaxel devices are safe and effective tools in peripheral arterial disease, especially at their current generations. Providers can use these devices and expect good outcomes for their patients without an increased mortality risk.

That being said, Dr. Katsonas does raise interesting questions. The 2018 Katsonas et al meta-analysis did show a significant increase in all-cause mortality. In his commentary, this effect appeared again when looking at all studies from 2008-2021. While there were shortcomings in the Katsonas paper, the fact remains that a mortality signal was present and hasn’t been fully accounted for. The fact that it seems to disappear when looking at studies from only 2018 onward could be indicative of the root cause. Moreover, the more recent studies did not subgroup based on device or paclitaxel dosing. The data he presents on the decrease of all-cause mortality risk over the years, as well as the trend of lower risk ratios with lower paclitaxel dosing, are suggestive that the mortality signal may be device-, device-generation, and/or paclitaxel dosage-dependent. Of course, this is only speculation based on available data, but could make excellent areas of inquiry should the question of safety in paclitaxel containing devices remain.

Dr. Katsonas’ final point is to not miss the “trees” (individual studies) for the “forest” (meta-analysis), as individual studies can yield insights that may be diluted in meta-analyses. However, he doesn’t really support this in his commentary, as most of his points are made by using grouping statistics based on multiple studies. Regardless, it is an important point to keep in mind when reading meta-analyses. Procedural practice and published literature are nuanced, and evidence-based medicine should be supported by both high-level meta-analyses as well as individual studies that befit the patient population and institutional experience.

Post Author
Sean Rogers, MD
Interventional Radiology Fellow, PGY-6
University of Massachusetts Chan Medical School

Radiofrequency Lung Ablation in ILD

Radiofrequency Ablation in Patients with Interstitial Lung Disease and Lung Neoplasm: A Retrospective Multicenter Study

Clinical Question

Is percutaneous radiofrequency ablation safe and effective against lung neoplasms in patients with interstitial lung diseases?

Take Away Point

Radiofrequency ablation is a feasible technique in combating lung neoplasms in patients with interstitial lung diseases but there are risks of post-procedural acute exacerbations which has a relatively high mortality rate of 45%.

Reference

Yamamoto A, Hiraki T, Ikeda O, et al. Radiofrequency ablation in patients with interstitial lung disease and lung neoplasm: A retrospective multicenter study. Journal of Vascular and Interventional Radiology. 2024;35(9):1305-1312. doi:10.1016/j.jvir.2024.06.010

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Study Design

Retrospective, observation, cohort study

Funding Source

No reported funding

Setting

Academic, Osaka Metropolitan University, et al, Japan

Figure

Summary

Interstitial lung diseases are generally irreversible with poor prognosis. There is no optimal therapeutic approach for concomitant lung neoplasms, which has a frequency of 10-20%. Radiofrequency ablation is a safe and effective treatment strategy for inoperable primary and metastatic lung lesions. The authors of this paper decided to investigate the safety and efficacy of radiofrequency ablation in combating lung tumors in patients with interstitial lung diseases due to lack of pertinent data.

The authors performed a multi-institutional retrospective observational study acquiring data of all the patients diagnosed with lung neoplasm and interstitial lung disease from April 2002 and October 2017 who underwent radiofrequency ablation, with their respective images reassessed by radiologic review. After central radiologic review excluded patients who did not have interstitial lung disease, 49 patients remained in the sample, 43 men and 6 women. Within the 49 patients, there were 64 tumors—34 of which were primary neoplasms and 30 of which were metastatic—with 66 treatment sessions.

Technical success was defined as completion of the radiofrequency procedure. Adverse events were based on the parameters set by the modified definitions of Society of Interventional Radiology, including unexpected increase in the level of care, prolonged hospital stay, or death. The following variables were also included in the study: local tumor progression, overall survival, and acute exacerbation of interstitial lung disease after ablation. Acute exacerbation diagnosis was based on radiologic or clinical diagnosis.

Technical success rate was 100%. While no adverse events occurred during the procedure, multiple events occurred after the procedure, the most frequent being pneumothorax in 53% (35/66 treatment sessions). The rest of the listed adverse events are summarized in Table 3 provided in this article. Acute exacerbations occurred in 8% of the study (5 patients). Among these 5 patients, 3 passed away despite initiation of steroid treatment (60%). The events of acute exacerbations did not differ significantly between patients with UIP (8%) and those without UIP (7%). Additionally, onset of acute exacerbation always occurred at least 8 days after radiofrequency ablation. Univariate analysis determined that pleural effusion and fever were statistically significant risk factors for development of acute exacerbations. Local tumor progression rate was 43% at one year. The overall survival rate at one, three, and five-years were 83%, 62%, and 36%, respectively.

While the results have demonstrated that radiofrequency ablation can be feasible for treating lung neoplasm in patients with interstitial lung disease, the results do not provide consensus recommendations. With regards to procedural safety, prior literature has demonstrated that ablation for lung neoplasms is safe, with mortality rate <1%, which is significantly lower than the mortality rate in patients with interstitial lung disease reported in this series, at 5% per session. The rate of 8% for acute exacerbation and an associated mortality rate of 45% may seem alarming at first. However, the rate of acute exacerbation after surgery was similar to that of ablation at 9.3%, with a similar mortality rate at 43.9%. Similarly, acute exacerbation can occur after thoracic radiotherapy and pharmacotherapy. After all, patients with idiopathic pulmonary fibrosis and non-idiopathic pulmonary fibrosis interstitial lung diseases develop acute exacerbations at a rate of 10-20%, and 3-5%, respectively annually during the natural course. The safety profile of radiofrequency ablation for lung neoplasm should be considered within this specific patient population and not taken out-of-context.

With regards to the local tumor progression rates, various factors may have contributed, both from the operator and from the lesion pathology. The operator may not have had sufficient margin, partly due to the intention to minimize adverse events. Additionally, patients with severe emphysema or UIP may present challenges to the accurate identification of the overall tumor burden, complicating the assessment of local tumor progression. Furthermore, fibrotic changes such as those seen in usual interstitial pneumonia may reduce the ablation’s electrical and thermal conductivity, limiting the tumoricidal effect of radiofrequency ablation.

This study had several limitations apart from its retrospective design. Firstly, interstitial lung disease diagnosis was not based on pathological findings. Secondly, central reading to evaluate interstitial lung disease was only applied to those that were already diagnosed as such, making the study prone to additional selection bias. Multivariate analysis to identify independent risk factors for acute exacerbations could improve the quality of the study. Sub-analyses, which may require a larger study, focusing on patients with primary neoplasms, and patients with metastatic lesions, separately, will provide further clinically relevant information and guidance.

Commentary

Despite several limitations, this article assessing radiofrequency ablation for the treatment of lung neoplasms in patients with concomitant pulmonary pathologies like interstitial lung disease is of significant clinical relevance. Risk factors that predispose patients to interstitial lung disease such as smoking are very prevalent, especially in certain countries like Japan. Referring and treatment physicians of patients with interstitial lung disease need information specific to the patient population. Clinical guidelines and treatment algorithms also require such information for development and refinement. In conclusion, radiofrequency ablation appears feasible in patients with interstitial lung disease with a risk of post-procedural acute exacerbation grossly similar to other treatment modalities.

Post author
Naeem Patel, DO
Radiology Resident, PGY4
Department of Radiology, Interventional Radiology Division
Hartford Hospital, Hartford, CT
@Naeemp7Patel

Systemic Review of Persistent Sciatic Artery Management

Safety and Effectiveness of Endovascular Treatment of Complications Associated with Persistent Sciatic Artery: A Qualitative Systematic Review

Clinical question

Is endovascular therapy with stent grafts (SGs) a safe and effective approach to treat complications associated with persistent sciatic artery (PSA)?

Take away point

The current review demonstrated good technical and clinical success rates and a low risk of adverse events with endovascular stent graft management of persistent sciatic artery.

Reference

Koike, Y., Motohashi, K., & Kato, S. (2024). Safety and Effectiveness of Endovascular Treatment of Complications Associated with Persistent Sciatic Artery: A Qualitative Systematic Review. Journal of Vascular and Interventional Radiology.

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Study design

Systemic review, qualitative

Funding Source

None

Setting

Academic

Figure

Summary

Persistent sciatic artery (PSA) is a rare vascular anomaly occurring in 0.025%–0.040% of the population, where the sciatic artery fails to regress during fetal development and continues to supply the lower limb. This anomaly often results in symptoms, with 80% of patients being symptomatic and 48% developing buttock aneurysms due to repetitive trauma and compression from its anatomical position. These aneurysms can lead to complications such as thrombotic occlusion, distal embolization, and even amputation. The primary treatment goals for symptomatic PSA are to prevent distal embolization and aneurysm rupture, typically through bypass surgery combined with embolization. Recently, stent graft (SG) placement has gained attention as an alternative treatment, although concerns about SG durability, potential fracture, and occlusion remain due to the repetitive trauma in the PSA's location. This systematic review aims to assess the safety and effectiveness of endovascular SG placement for treating PSA complications.

This systematic review, registered with the University Medical Information Network, analyzed existing literature on endovascular treatment of persistent sciatic artery (PSA) complications using stent graft (SG) placement. Following PRISMA guidelines, the study included patients with PSA complications such as aneurysms, rupture, or thrombosis, and excluded those without SG placement or without complications at risk of rupture. The literature search, conducted across multiple databases, identified eligible studies based on a predefined PICOS framework. Two authors independently screened and extracted data, resolving discrepancies by consensus. Outcomes assessed included technical and clinical success, patency, SG-related adverse events, reinterventions, amputations, and mortality. Statistical analyses, including Kaplan-Meier curves and Cox regression, were performed to evaluate the associations between SG characteristics and outcomes, with significance set at a p-value of ≤0.05.

The systematic review included 40 records of patients who underwent endovascular treatment with stent grafts (SGs) for persistent sciatic artery (PSA) complications. The study analyzed 31 case reports, 2 case series, and 7 conference proceedings, with a total of 40 patients (median age 67) treated across 41 limbs. Most patients presented with lower limb ischemia or aneurysm. The technical success rate was 100%, but 9.8% of limbs experienced intervention-specific adverse events, including intraprocedural dissection and thrombotic complications. The study found primary and secondary patency rates of 81.5% and 94.5% at 1 year, respectively, with SG occlusions mainly occurring within 2 years. The clinical success rate remained high at 95.7% over two years. SG fracture was rare, and no endoleaks or infections were reported. Univariate analysis showed no significant association between SG characteristics and primary patency rates.

The discussion highlights that endovascular treatment using stent grafts (SGs) for persistent sciatic artery (PSA) complications is effective, showing high technical and clinical success rates with a low risk of adverse events (AEs). The midterm patency and durability of SGs were found to be acceptable, although factors influencing patency remain unclear. The review supports SG placement as a preferable first-line therapy, especially for PSA aneurysms without occlusion, and suggests that endovascular approaches are increasingly favored due to their minimally invasive nature. The discussion also compares the findings with previous reviews and studies, noting similar success rates but emphasizing the need for more consistent follow-up and reporting to better understand long-term outcomes and the potential impact of anatomical factors on patency. The authors recommend SGs as a first-line treatment while acknowledging the limitations of the current data, including potential selection bias and inconsistencies in study methodologies.

Systemic Review of Renal Artery Aneurysm Management

A Qualitative Systematic Review of Endovascular Management of Renal Artery Aneurysms

Clinical question

How does endovascular management of renal artery aneurysms fare in a qualitative systemic review of the literature?

Take away point

Systematic review of 454 renal artery aneurysms management demonstrated that endovascular approaches were associated with high technical success (96%), a low rate of moderate-to-severe adverse events (6.7%; the most common being renal infarction, but only 16% were clinically evident), and no periprocedural mortality (0%).

Reference

Sheahan, K.P., Alam, I., Pehlivan, T., Pasqui, E., Briody, H., Kok, H.K., Asadi, H. and Lee, M.J., 2024. A systematic review of endovascular management of renal artery aneurysms. Journal of Vascular and Interventional Radiology.

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Study design

Systemic review

Funding Source

None

Setting

Academic

Figure

Figure. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flowchart showing the search, review, and selection process. RAA = renal artery aneurysm.

Summary

Renal artery aneurysms (RAAs) are increasingly detected incidentally, with rupture rates of 3%–5% and associated mortality, especially in nonpregnant patients. Key risk factors include aneurysm size over 20 mm, progressive enlargement, and hypertension, with treatment recommended for aneurysms larger than 2-3 cm, progressive growth, or in pregnant women due to the high mortality risk during peripartum rupture (peripartum rupture is associated with mortality rates of up to 100% for the baby and 80% for the mother). Although there is limited prospective data comparing operative or endovascular repair with surveillance, endovascular techniques have emerged as the preferred treatment for most RAAs due to advancements in technology, quicker recovery times, and high success rates. This study reviews the evidence on endovascular treatment of RAAs, focusing on technical success, adverse events, treatment options, and intermediate to long-term outcomes to guide optimal management strategies.

This systematic review, registered with the PROSPERO database and conducted following Cochrane and PRISMA guidelines, aimed to evaluate the safety and effectiveness of endovascular treatment for renal artery aneurysms (RAAs). A comprehensive search of multiple databases identified studies published between 2000 and 2022, focusing on those with at least five patients undergoing endovascular treatment. Two authors independently selected and reviewed studies, with disagreements resolved through consensus. The review assessed RAA-related mortality, rupture rates, and secondary outcomes such as renal infarction and reintervention. Data analysis included descriptive statistics on outcomes, and a quality and risk-of-bias assessment was performed using the Risk of Bias in Nonrandomized Studies of Interventions tool. The study sought to provide clarity on optimal RAA management by reviewing technical success, adverse events, and long-term outcomes of endovascular techniques.

The systematic review included 26 single-center, retrospective observational studies published between 2007 and 2022, encompassing 13 cross-sectional studies, 6 cohort studies, and 7 case series. A total of 371 patients were reviewed, with a mean age of 53.8 years and a female predominance of 62%. Fibromuscular dysplasia was noted in 26% of cases, though its type was not specified. The majority (53%) of renal artery aneurysms (RAAs) were asymptomatic and most commonly located at the hilar bifurcation.

Endovascular management of renal artery aneurysms (RAAs) employed various techniques, each contributing to the high technical success rate of 96.69% observed across studies. The primary technique used was coil embolization, which accounted for 42% (n=191) of the procedures. This method involves the insertion of coils into the aneurysm to promote clot formation and vessel occlusion. Stent-assisted coiling was the next most common approach, used in 21.5% (n=98) of cases, where a stent is placed to maintain vessel patency while coils are deployed to occlude the aneurysm. Other techniques included the use of flow-diverting stents, liquid embolics, and covered stents, each chosen based on the aneurysm's characteristics and location. Despite the variety of methods, the overall complication rate was 22.9%, with severe adverse events occurring in 6.7% of cases. Mild complications, such as minor renal infarctions and postembolization syndrome (PES), were relatively common, while severe complications, including significant renal impairment, were rare. The need for reintervention was low, at 3%, typically due to issues like incomplete occlusion or reperfusion of the aneurysm sac.

Endovascular treatment of renal artery aneurysms (RAAs) is favored due to its reduced invasiveness, offering better outcomes compared to open surgery, especially for elderly patients and those with comorbidities. Techniques like coil embolization, stent grafts, and flow-diverting stents are employed based on aneurysm characteristics, with coil embolization being the most common but also associated with the highest number of mild adverse events. The study highlights the need for careful patient selection, particularly when dealing with complex aneurysms or when considering younger patients for stent grafts. Despite the technical success and low severe adverse event rate (6.7%), the risk of delayed aneurysm reperfusion necessitates ongoing surveillance. The discussion underscores the challenges of comparing different endovascular techniques and the need for standardization in adverse event reporting, antiplatelet therapy, and follow-up protocols to further refine treatment approaches.

Safety and efficacy of Computer Assisted Vacuum Thrombectomy

Clinical, Functional, and Quality of Life Outcomes after Computer Assisted Vacuum Thrombectomy for Pulmonary Embolism Interim Analysis of the STRIKE-PE Study

Clinical question

How safe and effective is Computer Assisted Vacuum Thrombectomy for treating Pulmonary Embolism?

Take away point

There is a significant reduction in pulmonary artery pressure and right ventricle to left ventricle ratios as well as improvement in 90-day functional and quality of life outcomes associated with the use of Computer Assisted Vacuum Thrombectomy.

Reference

Moriarty JM, Dohad SY, Schiro BJ, et al. Clinical, Functional, and Quality of Life Outcomes after Computer Assisted Vacuum Thrombectomy for Pulmonary Embolism: Interim Analysis of the STRIKE-PE Study. Journal of vascular and interventional radiology. Published online May 1, 2024. doi: https://doi.org/10.1016/j.jvir.2024.04.028

‌Study design

Prospective observational cohort study.

Funding Source

Industry sponsored; Penumbra.

Setting

International multi-institutional study across the USA and Europe.

Figure

Summary

The annual incidence of pulmonary embolism (PE) is increasing and there is significant associated morbidity for surviving patients in terms of decreased overall quality of life. Endovascular treatment strategies have promising clinical outcomes. But longer-term patient-reported outcomes and PE associated morbidity are lacking. The STRIKE-PE study is a muti-institutional prospective study evaluating the long-term safety and treatment outcomes after computer aided vacuum thrombectomy of PE. This article is the first interim analysis of the STRIKE-PE study and evaluates the safety and effectiveness of computer assisted vacuum thrombectomy (CAVT) for the first 150 patients through 90-day follow-up.

All 150 patients were treated with the Indigo Aspiration Mechanical thrombectomy system in combination with the automated computer assisted algorithm. The right ventricle to left ventricle (RV to LV) ratio and incidence of major adverse events within 48 hours were the primary endpoints of the study.
· The RV to LV ratio was assessed on computed tomography pulmonary angiograms.
· Major adverse events included device-related death, major bleeding, device associated pulmonary vascular or cardiac injury and clinical deterioration including prolonged end-organ hypoperfusion or cardiopulmonary resuscitation.

Quality of life and functional improvements were utilized as secondary endpoints.
· Functional outcomes were assessed using the Borg scale of dyspnea at rest and the New York Heart Association classification of heart failure.
· Quality of Life was assessed using the EQ-5D-5L questionnaire, the EQ visual analog scale and the Pulmonary Embolism Quality of Life questionnaire.

Overall, the authors found that the use of computer assisted vacuum thrombectomy was associated with a 16.3% reduction in pulmonary artery pressures, a 25.7% reduction in the RV to LV ratio. Four (2.7%) of the patients experienced major adverse events within 48 hours. Patients exhibited statistically significant improvements in their quality of life at 90 days after the procedure.

The authors discussed that their observed 25.7% reduction in RV to LV ratio was similar to other prospective single-arm clinical studies assessing endovascular approaches for the treatment of PE. The total device time in this study, 33.5 minutes, was lower, although the total procedure time was comparable to other aspiration thrombectomy studies. The reported major adverse events seen during the current study included major bleeding and device related clinical deterioration, which were similar to prior studies. Due to a relative paucity of data in literature, the authors were unable to compare the observed functional and quality of life improvements. However, the authors did emphasize that the FDA and the European Agency for the Evaluation of Medicinal Products both recommend monitoring patient-reported outcomes as effective endpoints in similar clinical trials. The limitations of the study included a lack of comparison with other procedural interventions and medical management with anticoagulation. In addition, as the functional and quality of life questionnaires are not specific to pulmonary embolism, concurrent treatment of other comorbid conditions may have confounded the data. Finally, there was potential bias as the RV to LV ratio was reported by the treating physicians and not through standardized core laboratory examination.

In conclusion, the authors reported that treating PE with computer assisted vacuum thrombectomy resulted in improved RV to LV ratios and pulmonary arterial pressures with an acceptable safety profile as well as improved functional and quality of life outcomes at 90-day follow-up.

Commentary

The authors reported the interim results from ongoing STRIKE-PE trial. The study was tailored to prospectively evaluate the safety and long-term outcomes of computer assisted vacuum thrombectomy with a large patient population from multiple institutions. The reported initial results demonstrated decreased right heart strain and improved 90-day functional and quality of life outcomes. There remained a paucity of data in literature examining the long-term patient outcomes after treatment of PE, which is of paramount importance for informing morbidity of surviving patients after PE treatment. The recognition of this importance by the FDA, and the inclusion of functional outcome assessment in this and other similar clinical trials represented progress in the field where long-term morbidity is regarded as important as the immediate clinical success. A potential area of improvement involves the development of PE-focused functional and quality of life measures, which can allow PE-specific assessment rather than a generalized morbidity questionnaire.

Approximately 3% of patients in this study experienced major adverse events associated with computer assisted vacuum thrombectomy, suggesting a strong safety profile. Also, the mitigation of blood loss can decrease the need for blood transfusion. Furthermore, the median ICU stay was 1 day and 38% of the patients did not require postprocedural ICU level of care. Finally, the total device time associated with computer assisted vacuum thrombectomy was less than similar mechanical thrombectomy devices though the total procedure time was comparable. This data can be leveraged by Interventional Radiology departments to acquire the necessary PE treatment equipment.

The STRIKE-PE trial is still ongoing, and it will be interesting to see the safety and immediate clinical outcomes of the entire patient population of 600 patients, as well as longer-term morbidity and functional outcomes. Future trials can also focus on comparing the efficacy of computer assisted vacuum thrombectomy with other methods of treatment. Overall, the initial interim results from the STRIKE-PE trial bolsters the use of computer assisted vacuum thrombectomy for PE with promising safety and effectiveness profile.

Post Author
Aniket Pandya, MD
ESIR Resident, PGY-4
University of Massachusetts Chan Medical School

Thermal Ablation for Hepatic Epithelioid Hemangioendothelioma

Image-Guided Thermal Ablation for Hepatic Epithelioid Hemangioendothelioma: A Multicenter Experience

Clinical question

Is image-guided thermal ablation safe and effective in patients with hepatic epithelioid hemangioendothelioma?

Take away point

Based on this retrospective multicenter review of 18 patients with 31 ablations, image-guided thermal ablation is a feasible and safe treatment option for patients with HEHE that resulted in local tumor control and a favorable long-term prognosis

Reference

Zeng, Q., Luo, Y., Yu, J., Li, X., Jiang, T.A., Xie, X., Dong, G. and Liang, P., 2024. Image-Guided Thermal Ablation for Hepatic Epithelioid Hemangioendothelioma: A Multicenter Experience. Journal of Vascular and Interventional Radiology.

Click here for abstract

Study design

Retrospective, observational, descriptive study

Funding Source

None

Setting

Academic

Figure

Summary

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare vascular neoplasm with an incidence of less than 1 per million people and constitutes under 1% of hepatic malignancies. Despite its low-to-intermediate malignant potential, HEHE often necessitates treatment due to its multifocal presentation, potential for aggressive progression, and tendency for recurrence and metastasis. The European Society for Medical Oncology recommended surgical resection for stable unifocal or locoregional disease and liver transplantation for unresectable HEHE without extrahepatic disease. For patients ineligible for surgery, alternative treatments such as chemotherapy, radiation, immunotherapy, and antiangiogenic therapy are considered, albeit with varying outcomes. Image-guided thermal ablation has emerged as a potential treatment, particularly for those not suitable for surgery or as a bridge to transplantation. This retrospective study aims to evaluate the feasibility, safety, and effectiveness of thermal ablation for HEHE based on a multicenter experience.

The study involved a retrospective investigation across four hospitals. Informed consent was obtained from 18 patients with pathologically proven HEHE who underwent microwave or radiofrequency ablation between January 2013 and February 2023. Surgical treatment was initially recommended, but ablation was performed on patients ineligible for surgery due to contraindications such as low platelet counts, high international normalized ratios, severe organ dysfunction, or refusal of surgery. Procedures were performed under general anesthesia. Technical success and adverse events were evaluated with contrast-enhanced imaging three days post-ablation, with longer-term follow-ups approximately every three months to monitor intrahepatic distant metastasis, extrahepatic metastasis, local tumor progression, and progression-free survival. Post-ablation adverse events were categorized using the Clavien-Dindo classification within one month of the procedure.

22.2% of the included patients had extrahepatic involvement at diagnosis. Prior treatments included hepatic resection, transcatheter arterial chemoembolization, and systemic therapy. A total of 51 tumors, with a median size of 23.2 mm, were treated with image-guided thermal ablation in 31 sessions, resulting in a 93.5% technical success rate. The median hospitalization was 7 days, with no major adverse events reported. Over a median follow-up of 37.2 months, the median overall survival (OS) was 90.5 months, with OS rates at 1, 3, and 5 years estimated at 87.6%, 75.5%, and 75.5%, respectively. Recurrence occurred in 10 patients, with a median progression-free survival (PFS) of 23.8 months. Larger tumor size was significantly associated with decreased PFS. Patients without extrahepatic involvement had better PFS rates, and early-stage patients had higher PFS rates compared to intermediate-to-advanced-stage patients, although this was not statistically significant.

This multicenter investigation demonstrated that image-guided thermal ablation is a safe and effective treatment for patients with HEHE, achieving a 93.5% technical success rate and manageable minor adverse events. The 1-, 3-, and 5-year OS rates for ablation patients were comparable to those for hepatic resection or liver transplantation, although PFS rates were shorter, likely due to the higher tumor burden and aggressive disease progression in the ablation cohort. Extrahepatic involvement was associated with poorer outcomes, and larger tumor size was a predictor of decreased PFS. Despite these challenges, the repeatability of ablation sessions contributed to favorable OS rates, underscoring its potential as a treatment option. The study's limitations include its retrospective design, potential selection bias, and small sample size due to the rarity of HEHE. Further research is needed to evaluate the benefits of combining ablation with neoadjuvant therapies for larger or multifocal tumors and to determine its role on the HEHE treatment management pathway. In summary, thermal ablation offers favorable local tumor control and long-term effectiveness for HEHE patients ineligible for surgery or transplantation.

Commentary

The use of image-guided thermal ablation for patients with unresectable hepatic epithelioid hemangioendothelioma represents a promising and viable treatment option, as evidenced by the findings of this multicenter, albeit small, investigation. This study highlights the procedure’s safety and effectiveness, showcasing a high technical success rate of 93.5% and favorable overall survival rates comparable to those achieved through more invasive treatments like hepatic resection and liver transplantation.

One significant advantage of thermal ablation is its minimally invasive nature, which makes it suitable for patients who are not candidates for surgical management due to various contraindications. The repeatability of ablation also stands out, allowing for multiple sessions to manage recurrences effectively, potentially contributing to sustained overall survival rates.

However, the shorter progression-free survival rates observed in this study, compared to more invasive treatments, underscore the need for careful patient selection, intra-procedural ablation confirmation software, and potentially the integration of ablation with other therapies. The study's identification of larger tumor size as a predictor of worsened progression-free survival suggests that combining ablation with therapies such as chemoembolization could enhance outcomes for patients with larger or multifocal tumors.

In conclusion, this study provides preliminary evidence that image-guided thermal ablation is a valuable treatment for patients with unresectable hepatic epithelioid hemangioendothelioma, offering a balance of efficacy and safety. Further research will optimize its clinical utility and potentially expand its role in the management of hepatic epithelioid hemangioendothelioma.

DCB versus PTA in AVF

Comparison of Clinical Effectiveness and Safety of Drug-Coated Balloons versus Percutaneous Transluminal Angioplasty in Arteriovenous Fistulae: A Review of Systematic Reviews and Updated Meta-Analysis

Clinical question

What does the most updated meta-analysis say about the safety and clinical effectiveness of drug-coated balloons versus percutaneous transluminal angioplasty for arteriovenous fistula stenosis?

Take away point

Drug eluting ballons have been shown to have consistent benefits in treating arteriovenous fistulae compared to percutaneous transluminal angioplasty in both primary patency and target lesion revascularization at 6 and 12 months, without increased mortality.

Reference

Lee, H., Choi, H., Han, E. and Kim, Y.J., 2024. Comparison of Clinical Efficacy and Safety of Drug-Coated Balloons versus Percutaneous Transluminal Angioplasty in Arteriovenous Fistulas: A Review of Systematic Reviews and Updated Meta-Analysis. Journal of Vascular and Interventional Radiology.

Click here for abstract

Study design

Systematic review and meta-analysis

Funding Source

None reported

Setting

Academic

Figure

Figure 3. Forest plot of primary patency at 12 months. Pooled effect with 95% CI were estimated using a Mantel–Haenszel (M-H) random-effects model. DCB = drug-coated balloon; df = degree of freedom; PTA = percutaneous transluminal angioplasty.

Summary

Arteriovenous fistulae are primarily created for hemodialysis in patients with end-stage renal disease due to their lower infection risk and better maintenance compared to other types of access. However, they are usually plagued by stenosis and an eventual loss of patency. Percutaneous transluminal angioplasty is the conventional treatment, with drug-coated balloon emerging as a promising treatment option recently. Despite several systematic reviews and meta-analyses assessing the clinical effectiveness and safety of drug-coated balloons for arteriovenous fistulas and arteriovenous grafts, the results remain controversial. A comprehensive review of existing evidence and an updated meta-analysis were conducted to evaluate the clinical effectiveness and safety of drug-coated balloons compared to percutaneous transluminal angioplasty for arteriovenous fistula stenosis.

This study conducted a systematic review and meta-analysis following PRISMA guidelines, with a protocol registered in PROSPERO. An extensive search of MEDLINE, Embase, and Cochrane Library databases up to April 2023 used keywords related to "arteriovenous fistula," "drug-coated balloon," "angioplasty," and "hemodialysis." Studies were included if they involved patients with arteriovenous fistula stenosis, compared drug-coated balloon to standard or high-pressure percutaneous transluminal angioplasty, and reported primary patency, target lesion revascularization, or mortality. Only systemic reviews of randomized controlled trials, nonrandomized studies, or cohort studies were considered, excluding low-quality studies. Quality was evaluated using AMSTAR and appropriate bias assessment tools for original studies. Data synthesis involved narrative and quantitative analyses, with subgroup and sensitivity analyses to address heterogeneity and potential biases, using Revman 5.4 for meta-analysis and funnel plots for publication bias.

The results of this systematic review and meta-analysis are based on an extensive literature search that identified 257 systematic reviews, of which 11 were included. These reviews, published between 2019 and 2022, focused on patients with arteriovenous fistula stenosis undergoing angioplasty, comparing drug-coated balloon to standard or high-pressure balloon treatments. The primary outcome, primary patency, was assessed in 9 reviews, showing a general trend favoring drug-coated balloon at 6 and 12 months, with significant results in 7 outcomes and nonsignificant differences in 3 outcomes. Target lesion revascularization was reported in 3 reviews, indicating significantly lower target lesion revascularization rates for drug-coated balloon at 6 months and mixed results at 12 months. Mortality was reported in 4 reviews, showing no significant difference between drug and percutaneous transluminal angioplasty at 6 and 12 months. A meta-analysis update included 23 studies, revealing significantly more favorable primary patency for drug-coated balloon at 6 and 12 months but not at 24 months, and a lower risk of target lesion revascularization at 6 and 12 months. Mortality rates showed no significant difference at any time point. Subgroup analyses confirmed favorable primary patency for drug-coated balloon at 12 months across various device brands, study funding sources, and designs, with no evident publication bias.

The study highlighted the variability in outcomes due to heterogeneity among included studies, differences in study design, and various methodological factors. Despite these inconsistencies, the overall findings suggest that drug-coated balloon is more effective than percutaneous transluminal angioplasty in maintaining arteriovenous fistula patency without increasing mortality risk, although further well-designed studies are needed to confirm these results and address long-term outcomes and cost-effectiveness.

Commentary

This article provides a comprehensive and meticulous synthesis of current evidence on the use of drug-coated balloons compared to percutaneous transluminal angioplasty for treating arteriovenous fistula stenosis. By analyzing multiple systematic reviews and updating previous meta-analyses, the authors highlight the clinical benefits of drug-coated balloons, particularly in improving primary patency and reducing target lesion revascularization rates at 6 and 12 months. However, the study also underscores the variability and heterogeneity among the included studies, which pose challenges in drawing definitive conclusions. Notably, the review confirms that drug-coated balloons do not increase mortality risk, aligning with previous findings. Despite some limitations, including the need for more long-term data and consideration of cost-effectiveness, this article provides updated level 1 (SIR-A) evidence for drug-coated balloon’s efficacy and safety in the context of arteriovenous fistula stenosis. Further well-designed research may resolve existing discrepancies and provide better insights regarding longer-term clinical outcomes.

Predictive factors of Splenic Artery Aneurysm Growth

The Natural History of Splenic Artery Aneurysms: Factors That Predict Aneurysm Growth

Clinical question

What factors predict splenic artery aneurysmal growth?

Take away point

A larger baseline splenic artery aneurysm, the presence of a mural thrombus and low amounts of rim calcification translated to increased overall growth rate

Reference

An, T. J., Chen, X., Omar, O. M., Sutphin, P. D., Irani, Z., Wehrenberg-Klee, E., Iqbal, S., & Kalva, S. P. (2024). The natural history of splenic artery aneurysms: Factors that predict aneurysm growth. Journal of Vascular and Interventional Radiology, 35(7), 972–978. https://doi.org/10.1016/j.jvir.2024.04.007

Click here for abstract

Study design

Retrospective

Funding Source

None

Setting

Single academic institution-Mass General Hospital

Figure

Plots of the mean growth rate of splenic artery aneurysms (SAAs) based on different aneurysm characteristics. (a) SAAs with greater than 50% mural thrombus were associated with an increased rate of growth (0.65 mm/y). (b) SAAs with greater than 50% rim calcification were associated with a decreased rate of growth (0.14 mm/y). (c) SAAs greater than 2 cm in diameter cm were associated with an increased rate of growth (0.41 mm/y). (d) There was no significant difference in SAA growth rate based on aneurysm location. Error bars on the graphs denote the standard error of the mean. Double asterisks (∗∗) denote statistical significance (P < .05).

Summary

Splenic artery aneurysms (SAAs) are the third most common type of abdominal aneurysm, and represent up to 60% of visceral artery aneurysms. Despite their low incidence (0.8% at arteriography and 0.04%-0.1% at autopsy), increased use of cross-sectional imaging has led to more frequent incidental detections of splenic artery aneurysms. Higher incidences are noted in women and patients with conditions such as atherosclerosis, vasculitis, vasculopathy, and portal hypertension. Although typically asymptomatic, splenic artery aneurysms can rupture and cause life-threatening hemorrhages, with increased rupture risks associated with pregnancy, portal hypertension, pseudoaneurysm, and concurrent vasculitis. Both endovascular and surgical treatments for SAAs show high success and low mortality rates, particularly for asymptomatic aneurysms larger than 2 cm.

This study was done to look at progression of splenic artery aneurysms to ascertain any predictive factors for increased growth which may ultimately lead to life-threatening rupture. This retrospective study used 30 years of patient imaging from 1990-2020 encompassing 132 patients with median age of 66.6 years who had multiple cross-sectional CT and/or MR studies. Patients were excluded if they were under 18, those who had previous correction by endovascular or surgical intervention, and those with splenic pseudoaneurysms or false aneurysms. Multivariable linear regression was performed using aneurysm growth rate as a continuous dependent variable.

In the study, 89% of the patients had a history of hypertension, 64% history of smoking, 31 % with a history of diabetes and 11% with a history of portal hypertension. Most splenic artery aneurysms (61%) remained stable, with a low median growth rate of 0.60 mm/year. Splenic artery aneurysms with >50% of mural thrombus, and a baseline size greater than 2 cm, had increased rates of splenic artery aneurysmal growth. Splenic artery aneurysms with greater than 50% rim calcifications were negatively correlated with aneurysm growth rates. 88% of patients were managed conservatively.

Overall, the authors conclude that there is a trend toward nonoperative surveillance and increased endovascular intervention in the management of splenic artery aneurysms. Formal published guidelines were based on retrospective data, recommending treatment for nonruptured splenic artery aneurysms greater than 3 cm, those increasing in size, or in high-risk patients. Based on the data presented in the current series, for patients with positive predictive factors including baseline size > 2 cm and > 50% mural thrombus, preventive interventions may be warranted. Limitations include the retrospective design, non-standardized protocols, low incidence of adverse events, and potential imaging modality discrepancies.

Commentary

The authors initially found large proportion of the cohort to have existing comorbid conditions of smoking, diabetes, and hypertension with known involvement in aneurysmal formation and growth. Nevertheless, statistical analyses revealed that the factors associated with aneurysmal growth, specifically in the context of splenic artery aneurysm, were mural thrombus, baseline size, and rim calcifications. These new predictors can guide procedural timing in those with increased risks of life-threatening rupture.

It is often informative to utilize large amounts of data obtained over time to uncover obscure trends; but this approach can also carry significant bias and blind us from evolving environmental factors that could have influenced these patients’ disease course. In addition, it may overlook technological advances in diagnostic imaging in the long timespan, which could have implications in aneurysmal diameter measurements and growth rate calculations. To expand on the current study design would entail prospective data and diverse patient populations. Optimal timing for referral to endovascular or surgical intervention, and follow-up interval estimation, will be the next steps.

Post Author
Christopher Loiselle, DO, MS
PGY-1 General Surgery
Rutgers-Robert Wood Johnson Medical School
@Caloiselle

Claim-Based Method for IR Identification

A Claims-Based Method for Identification and Characterization of Practicing Interventional Radiologists

Clinical question

How to identify practicing interventional radiologists when most of them are listed as diagnostic radiologists on national claims data sets?

Take away point

A claims-based method, using percent IR-related work effort, may provide generalizability and comparability for identifying practicing interventional radiologists.

Reference

Waid, M.D., Rula, E.Y., Hawkins, C.M., Findeiss, L. and Liu, R., 2024. A Claims-Based Method for Identification and Characterization of Practicing Interventional Radiologists. Journal of Vascular and Interventional Radiology, 35(6), pp.909-917.

Click here for abstract

Study design

Healthcare policy and economics study

Funding Source

Society of Interventional Radiology (SIR), Workforce Research Division

Figure

Summary

The article discusses the challenges and proposed solutions for accurately identifying practicing interventional radiologists (IRs) using claims data. Despite many diagnostic radiologists (DRs) performing IR work, self-designated specialties often underrepresent the IR field, necessitating a reliable method to define and identify IRs for research purposes. The study found that a significant majority (around 80%) of IRs were listed as self-designated diagnostic radiologists in both Medicare and private insurance data. As the proportion of work devoted to IR-related services increased, more effort was allocated to surgical, invasive, and evaluation and management services, with less focus on noninvasive imaging.

The research aimed to develop and test an operational definition for identifying IRs based on claims data, using data from Medicare and commercial insurance claims. A major finding was that self-designated interventional radiologists comprised only a minority of those identified as practicing IRs at various work effort thresholds. The study demonstrated that as the percentage of IR-related work increased, the proportion of procedural and evaluation/management services rose, while noninvasive imaging efforts declined. This pattern was consistent across both Medicare and private insurance data.

Demographically, practicing IRs were more likely to be male, work in metropolitan areas, have fewer years since graduation, and be in smaller practice groups. The study proposed a methodology to improve the identification of IRs in claims data, which is important for advancing IR-related health services research. The authors emphasize that their approach aims to create consistent and replicable samples of IRs for research, rather than making judgments on specialty designations. This methodology is expected to facilitate better comparisons and conclusions in future IR-related studies.

Commentary

The demographic insights provided by the study, such as the higher likelihood of IRs being male, working in metropolitan areas, and being relatively early in their careers, offer valuable context for workforce planning and policy development. Additionally, the finding that IRs tend to work in smaller practice groups could inform strategic decisions in practice management and resource allocation.

But the most interesting finding in the article is the discrepancy between self-designated IRs and those identified through claims data, highlighting an underrepresentation of IR in national claims data. This underscores the potential significance of claims-based identification to capture the full IR workforce. The methodology's ability to discern IRs by analyzing the proportion of work devoted to IR-related services versus noninvasive imaging is a good framework that can enhance the accuracy of IR specialty identification.

Disc versus Bone? Osteomyelitis Discitis Biopsy

Percutaneous Disc Biopsy versus Bone Biopsy for the Identification of Infectious Agents in Osteomyelitis/Discitis

Clinical question

Which diagnostic approach is more effective for vertebral discitis and osteomyelitis: intervertebral disc biopsy or vertebral body biopsy?

Take away point

Disc biopsies may provide superior diagnostic accuracy for vertebral discitis and osteomyelitis when compared to bone biopsy.

Reference

Zamarud A, Kesten J, Park DJ, et al. Percutaneous Disc Biopsy versus Bone Biopsy for the Identification of Infectious Agents in Osteomyelitis/Discitis. J Vasc Interv Radiol. 2024;35(6):852-857.e1. doi:10.1016/j.jvir.2024.02.016

Click here for abstract

Study design

Retrospective, observational, cohort study

Setting

Academic setting

Figure

Figure 1. Representative images from a disc biopsy procedure. A 75-year-old man with back pain underwent (a–c) magnetic resonance (MR) imaging and (d–f) fluoroscopy-guided bone biopsy. Sagittal (a) T2, (b) T1, and (c) contrast-enhanced MR images showed findings suspicious for L4/L5 discitis (arrow) and osteomyelitis of L4 and L5 (arrowheads). Percutaneous biopsy of the L4/L5 was performed in an oblique (d, e) anteroposterior and (f) lateral view. (d) A safe trajectory was noted on the oblique anteroposterior view (hemostat marker), and (e) an introducer needle was advanced in plane on this view into the disc space (arrow). (f) The introducer stylet was then removed, and a biopsy needle was used to sample the disc space (arrow).

Summary

Vertebral discitis and osteomyelitis (VDO) are severe spinal infections, potentially leading to significant neurological deficits and structural spinal damage. In addition to non-invasive imaging (MRI) to localize and characterize the extent of the infection, biopsy of the affected disc and/or vertebral body is obtained via a percutaneous image-guided approach (fluoroscopy or CT) for identification of the causative organism to tailor antibiotic treatment. The decision to perform a biopsy of the affected disc or vertebral body is typically left to the discretion of the proceduralist. This retrospective cohort study aimed to compare the diagnostic yield of disc biopsies versus vertebral body biopsies in patients with suspected VDO. It was hypothesized that percutaneous sampling of the disc rather than the affected vertebra would be more likely to yield a positive tissue culture as infection of the disc is believed to be the inciting event in most patients.

Patients included in the study underwent biopsy procedures between 2019 and 2023 due to suspected VDO. Inclusion criteria required patients to be >= 18 years of age with presumed VDO based on MR imaging who undergone percutaneous biopsy. Data were extracted from EMR, focusing on biopsy procedure details, culture results, patient demographics, imaging findings, and treatment outcomes. 66 patients were included in the study–36 had disc biopsies, 30 had vertebral body biopsies, and 6 (3 in each group) underwent repeated procedures given initial negative tissue sampling result. Biopsies were performed by 5 different neurointerventional radiologists and 1 neurosurgeon. The decision to biopsy the disc or bone was at the discretion of the physician with varying techniques. The primary outcome measure was the culture yield (positive or negative) after percutaneous sampling. Statistical analyses included chi-square tests and Fisher’s exact tests to compare positivity rates between the biopsy methods.

Patient characteristics did not different significant between the two groups, except for the history of intravenous drug use (26.7% compared with 5.5% in patients who underwent bone biopsy and disc biopsy, respectively). Disc biopsies had a significantly higher rate of positive cultures compared to bone biopsies; 41% compared to 15% There were no statistically significant association between the biopsy culture results and pre-biopsy antibiotic administration. Neither were there any significant association between pre-biopsy blood cultures and biopsy culture results; in fact, 90% of the cases had a negative blood culture prior to the biopsy. No adverse events were noted after the procedure in either procedure group.

The authors discussed the positive implications for clinical practice, including improved pathogen identification and thus more tailored antibiotic therapy for VDO. The authors’ findings corroborated with previous studies that have reported low diagnostic yields from bone biopsies. Limitations of the study included its small scale and retrospective nature. Overall, the authors concluded that percutaneous biopsy of VDO should prioritize sampling of the disc to increase the likelihood of a positive tissue culture and allow tailored narrowed antibiotic coverage.

Commentary

This retrospective study addresses the clinically relevant question of whether percutaneous biopsy for VDO should prioritize sampling the disc or bone to increase the probability of a positive tissue culture, enabling more targeted antibiotic therapy. 

However, the small sample size, the single-center nature of the study, and the potential bias introduced with each physician choosing a biopsy type at their own discretion may limit the strength of these results. Additionally, there was a minor discrepancy in culture results and results from histologic analysis. Two disc biopsy patients and 4 bone biopsy patients with negative culture results had an infectious etiology during histologic analysis. This suggests that histologic analysis may be complementary to tissue culture in detecting certain infections and should be explored in future studies. The significant difference in intravenous drug use history between the two groups could have also introduced a confounding variable and thus may have influenced the difference in outcomes slightly. This study could have benefitted from a multivariate analysis or propensity score matching to account for this difference. 

Despite all of these limitations, this study presents encouraging findings regarding the benefits of prioritizing percutaneous disc biopsy over bone biopsy for VDO. To integrate this approach into clinical practice, additional studies with larger sample sizes studied at multiple institutions and a more uniform cohort are necessary. Overall, these findings are the first step in shifting the clinical decision making of physicians in this setting and may prompt new guidelines in favoring percutaneous disc biopsy for VDO.

  

Post Author
Danielle Millner Balagtas, BA
MD Candidate, Class of 2027
University of Massachusetts Chan Medical School
@daniellelmb

VR for IR Sedation?

Digital Sedation in Interventional Radiology: Reducing Pain and Anxiety Through Virtual Reality During Peripherally Inserted Central Catheter Placement and Fine Needle Aspiration Thyroid Biopsy

Clinical question

Does the use of virtual reality (VR) as a non-pharmacologic adjunct have analgesic and anxiolytic effects during Peripherally Inserted Central Catheter (PICC) placement and Fine Needle Aspiration (FNA) thyroid biopsy?

Take away point

Implementation of VR as a non-pharmacologic adjunct can reduce pain during some interventional radiology procedures; therefore, showing promise as an alternative to pharmacological approaches.

Reference

Schaake, R., Leopold, I., Sandberg, A., Zenk, B., Shafer, L., Yu, D., Lu, X., Theingi, S., Udongwo, A., Cohen, G. S., & Maresky, H. S. (2024). Virtual reality for the management of pain and anxiety for IR procedures: A prospective, randomized, pilot study on Digital Sedation. Journal of Vascular and Interventional Radiology, 35(6), 825–833. https://doi.org/10.1016/j.jvir.2024.03.004

Click here for abstract

Study design

Prospective, single-center randomized controlled trial with 107 patients.

Funding Source

This study was supported by the Lewis Katz School of Medicine at Temple University.

Setting

Academic setting, Lewis Katz School of Medicine at Temple University.

Figure

Figure 1(a) Image of virtual reality tropical island environment used in trials. (b) Image of study participant viewing virtual reality during peripherally inserted central catheter placement.


Figure 4(a) Estimation plots for paired data of individual VAS pain scores before and after thyroid biopsy for individuals randomized to SOC (n = 22) vs SOC+VR (n = 25). (b) Estimation plots for individual VAS anxiety scores for before and after thyroid biopsy for individuals randomized to SOC (n = 22) vs SOC+VR (n = 25). Tufte slope graphs are presented for each patient, connecting pre- and postprocedural VAS scores. Mean difference and 95% confidence intervals bars are plotted below each panel. PICC = peripherally inserted central catheter; SOC = standard of care; VAS = visual analog scale; VR = virtual reality.

Summary

Schaake et al. examined the use of virtual reality (VR) as a form of “digital sedation” to reduce pain and anxiety during Interventional Radiology (IR) procedures that typically do not require pharmacologic sedation, such as peripherally inserted central catheter (PICC) placement and fine-needle aspiration (FNA) thyroid biopsies. A prospective, single center randomized controlled trial was conducted with a sample size of 107 patients assigned to either a Standard of Care or Standard of Care plus Virtual Reality. The PICC cohort consisted of 59 patients with a median age of 53.1, while the thyroid biopsy cohort consisted of 48 patients with a median age of 60.1. Of note, the following groups of patients were excluded from the study: declining to participate, inability to provide consent, emergency procedures, administration of general anesthesia/moderate sedation, visual/hearing deficits, pregnancy, current prisoner status, nerve/sensory deficits over the area of procedure, or coronavirus disease 2019–positive status.

The VR procedure utilized the “Emmarye” (VRAL, Philadelphia, Pennsylvania) environment where the patient viewed a tropical environment with a sunset sky and ambient audio of the ocean and seagulls. A fairy would also appear engaging users in breathing exercises and giving reminders to remain still. Participants in the study completed an assessment of anxiety and pain using visual analog scales both pre- and post-procedure. Heart rate and blood pressure were also obtained during the procedure. Statistical analysis included a one-way ANOVA comparing the two groups with respect to pain and anxiety scores, ultimately indicating that VR significantly reduced pain scores during fine needle aspiration of the thyroid. Additionally, a trend was observed without statistical significance showing reduced anxiety during thyroid biopsies, as well as reduced pain and anxiety during peripherally inserted central catheter placement. Schaake et al. concluded that VR could be implemented to alleviate patient pain and anxiety during minimally invasive IR procedures, without increased procedural duration or risks of adverse events. They also contextualized these findings with other studies demonstrating the efficacy of using VR during simple procedural interventions in medicine, such as reducing pediatric patient’s anxiety and pain during orthopedic cast removal.

Commentary

As healthcare continues to integrate technological advancements, the use of virtual reality to improve patient comfort is an intriguing area worthy of exploration. Patients often experience pain and anxiety around procedures. While pharmacologic anxiolytics and analgesics play an important role in procedural care, their adverse effects, especially in an epidemic of pain medication misuse and overuse, should not be overlooked. Therefore, this study’s investigation on non-pharmacologic methods to improve patient comfort during interventional radiology procedures is illuminating. The methodology incorporated a unique healthcare-oriented VR environment, established scales for pain and anxiety measurements, and appropriate analytic statistics. The results, though limited by small sample size, two procedures typically not requiring sedation, and missed opportunities of capturing granular procedural details, are promising for the use of VR for pain and anxiety control peri-procedurally.

Nevertheless, there are several important considerations or even obstacles to potential wider clinical application of VR. First, the initial cost of VR equipment and need for continual updates may be expensive. Second, the scope of VR is limited by procedure type. Certain procedures require patient feedback, or the patient may need to be physically adjusted into a position that could be obstructed by the VR headsets. Wearing VR headsets for lengthy procedures can also be uncomfortable for some patients and issues like battery life and technological difficulties may arise. Finally, patients might experience VR-related eye strain, headaches, or motion sickness. With motivated investments from the industry and continued technological advancements, however, these issues will be of ever decreasing concern.

This study offers an insightful view on the potential for advanced technology in patient care. Virtual Reality offers exciting possibilities in medicine, but more research is needed to ensure maximization of the benefits and minimization of adverse events. Ultimately, Schaake et al. demonstrate a promising outlook on how technology advances in the reality-virtuality continuum can improve the tolerability of health care interventions.

Post Author
Shabaz Khan, B.A
M.D. Candidate, Class of 2027
University of Massachusetts Chan Medical School
@shabaz_khan11