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.