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Monday, February 17, 2020

Radiofrequency Ablation Duration per Tumor Volume May Correlate with Overall Survival in Solitary Hepatocellular Carcinoma Patients Treated with Radiofrequency Ablation Plus Lyso-Thermosensitive Liposomal Doxorubicin


Clinical question
Does burn time per tumor volume (BPV) in radiofrequency (RF) ablation and lyso-thermosensitive liposomal doxorubicin (LTLD) combination therapy for solitary hepatocellular carcinoma (HCC) correlate with treatment outcomes?

Takeaway point
Overall survival (OS) benefits were correlated with higher BPV in the RF ablation + LTLD combination compared to RF ablation alone in this retrospective post hoc analysis.

Reference
Radiofrequency Ablation Duration per Tumor Volume May Correlate with Overall Survival in Solitary Hepatocellular Carcinoma Patients Treated with Radiofrequency Ablation Plus Lyso-Thermosensitive Liposomal Doxorubicin, Volume 30, Issue 12, 1908-1914.

Click here for abstract

Study design
Post hoc analysis of the double-blind, randomized controlled phase III HEAT study of RF ablation only versus RF ablation + LTLD in patients with HCCs 3-7 cm in diameter.

Funding Source
Intramural Research Program of the National Institutes of Health and the National Institutes of Health Center for Interventional Oncology (grants ZID# BC011242-9 and CL040015-9). The National Institutes of Health has a Cooperative Research and Development Agreement with Celsion Corporation (Lawrenceville, New Jersey).

Setting
NIH, United States of America.






Figure 2. Hazard ratio versus BPV cutoff. As patients with smaller values of BPV were excluded, the hazard ratio decreased, representing improved benefit for patients receiving RF ablation + LTLD compared with patients receiving RF ablation only. When patients with < 2 min/mL BPV were excluded, the hazard ratio was 0.7, which meant survival of patients receiving RF ablation + LTLD improved 42.8% compared with patients receiving RF ablation only. With exclusion of patients with < 3.4 min/mL BPV, the hazard ratio and survival improvement for patients receiving RF ablation + LTLD became 0.5 and 100%, respectively, compared with patients receiving RF ablation only.

Summary


Radiofrequency (RF) ablation, despite its widely adopted and successful treatment of hepatocellular carcinoma (HCC), has limited results for tumors > 3 cm. Alternative treatment methods, such as the synergistic combination of RF ablation and lyso-thermosensitive liposoam ldoxorubicin (LTLD), are in development. Although the phase III HEAT study did not demonstrate significant difference in progression-free survival (PFS) and overall survival (OS) between RF ablation only and RF ablation + LTLD, initial post hoc subgroup analysis in patients with > 45 minutes dwell time demonstrated improved OS of patients receiving RF ablation + LTLD compared to RF ablation only. Based on the LTLD formulation and pharmacokinetic modeling, it was hypothesized that RF ablation duration with respect to tumor volume would contribute significantly to treatment outcomes of RF ablation + LTLD in HCC.

HEAT study data was analyzed retrospectively. Original data was a double-blind, randomized controlled study with 701 patients of HCC between 3 cm and 7 cm distributed between RF ablation only and RF ablation + LTLD. Only patients with solitary tumors were further analyzed (n = 210 patients who received RF ablation only; n=227 patients who received RF ablation + LTLD). Hazard ratios were calculated with incremental threshold values of BPV. A univariate and multivariate Cox proportional hazard model was used for analysis.

No significant difference was found in terms of tumor volume, average burn times, or BPVs between the two treatment arms. Multiple covariate Cox survival analysis demonstrated BPV as a significant effect modifier, with each 1 min/mL increase in BPV contributing to an increase of 17.6% in overall survival in the RF ablation + LTLD arm compared to RF ablation alone. Univariate Cox survival analysis with incremental BPV cutoff values demonstrated gradually decreasing hazard ratios, signifying more pronounced effects of BPV on OS with higher threshold of BPV. Independently performed univariate Cox analysis within each treatment arm confirmed significant effects of BPV on OS in the RF ablation + LTLD arm; but not on PFS, nor in the RF ablation only arm. Feasibility analysis demonstrated that almost 80% of all examined solitary tumors could have been treated with a BPV of 2 min/mL if available burn time was 100 minutes.

Commentary


The authors in this study have demonstrated a potentially significant effect of BPV on the treatment outcomes of RF ablation + LTLD in solitary HCC between 3 cm and 7 cm through a post hoc analysis of the phase III HEAT study data. Results suggested a critical role of adequate burn time in RF ablation + LTLD treatment and BPV as a normalization/stratification metric. This study has its limitations given its retrospective post hoc nature as ablation time and other important variables were not included in the original analysis plan. HCCs with significant tumor volumes (7 cm tumor would equate to an ablation time of 360 minutes with a BPV of 2 min/mL) were likely receiving disproportionately lower BPVs. Therefore, the effects of higher BPVs on overall survival could not be safely separated from the inherent survival benefit of having a smaller HCC. However, the call for a more standardized determination of RF ablation time, especially in the RF ablation + LTLD combination regimen given its preclinical mechanistic data, should not be understated. Future prospective studies should be conducted to further evaluate the effects of ablation time in RF ablation + LTLD treatment for HCC and the potential of using BPV as a standardization metric.


Post author
Ningcheng (Peter) Li, MD, MS
Integrated Interventional Radiology Resident, PGY-3
Department of Interventional Radiology
Oregon Health and Science University, Dotter Interventional Institute
@NingchengLi

Monday, February 10, 2020

A Descriptive Revenue Analysis of a Wound-center IR Collaboration To Treat Lower Extremity Venous Ulcers


Clinical question
How much revenue will be created by treating patients with venous leg ulcers in a joint collaboration between a wound care center and IR?

Take-away point
This joint venture between IR and wound care clinic generated revenue not only through procedures but also E&M, and imaging.

Reference
Ruohoniemi, David M. et al. A Descriptive Revenue Analysis of a Wound-Center IR Collaboration to Treat Lower Extremity Venous Ulcers. Journal of Vascular and Interventional Radiology, Volume 30, Issue 12, 1988 - 1993.

Click here for abstract

Study design
Retrospective review of 36 venous ulcer patients

Funding source
None

Setting
Academic center, New York University School of Medicine





Figure 3. Relative wRVU contribution to total wRVU by category. (b) Relative revenue contribution by category. wRVU=workrelative value units.

Summary


Treatment of venous leg ulcers (VLU) requires a collaborative effort with a wound care center. The authors studied the revenue generated by developing a collaborative effort with the wound care center. Patients referred to IR were patients with previous stents, filters or what was considered “more difficult venous disease”. Patients were initially evaluated in a dedicated outpatient facility. Follow up was usually at 3 and 6 months, at which time further intervention or imaging was considered.

36 patients were included in the study, 15 patients underwent (16 procedures), 21 were evaluated but did not undergo an intervention. Sources of revenue included E&M visits (initial evaluation and follow up, diagnostic imaging (before and after procedure) and procedures. CPT codes were used to account for E&M visits, diagnostic studies and procedures. The professional component (wRVUs) was calculated based on the E&M visits, diagnostic imaging and procerus.

The authors report 70 total clinic visits (36 initial, 34 follow up) and 3.6 new consultations per month. 31 pre-procedural imaging studies were ordered and procedural patients required 11 post-procedure studies. The total wRVU generated from this venture was 518.15, 24% wRVUS were due to E&M, 10% from diagnostic studies and 66% from procedures. 86% of wRVUs were due to procedure patients. This translated to a total revenue of $37,522 over 10 months, 58% was due to procedures, 23% to E&M and 28% to diagnostic imaging. Intervention patents accounted for 80% of the revenue, and on average the individual patient revenue was $624 (range $110-$3,077).

The findings of the study support the concept that clinical involvement is not only good for patient care, but can also result in revenue for an IR practice. The authors use several examples to show how E&M codes provide significant revenue to other specialties (20% of revenue for vascular surgery and 40% for cardiology). The authors highlight that the revenue was derived from CMS rates and therefore it underestimates revenue by not taking into account private payers. The study also references data from an IVC filter clinic that generated $712 per patient, which was more than the average revenue per patient in the joint wound care clinic collaboration ($624), but less than the median intervention patient revenue ($1,931) and less than the pathway per patient revenue ($1,042). Overall an IVC filter clinic will lead to $22,775 over 10 months (compared to the $35,000 in the joint venture).

The authors identify that this study is limited by data from a single tertiary center, as well as lack of data for actual collections and charges, technical procedural revenue and hospital procedural revenue.

In conclusion, the authors find that a joint wound care-IR collaboration in the care of VLU patients may lead to substantial revenue from not only procedures but also E&M and diagnostic imaging.

Commentary


The authors provide more evidence that IR clinic and IR clinical involvement, is not only good medical practice, but may also become an important source of revenue. The authors provide examples on how similar specialties (Vascular surgery and Cardiology) derive significant revenue from E&M codes. It is clear that patients that undergo procedures, lead to a higher revenue, but the revenue generated from non-procedure patients is not negligible (20% of total revenue). Joint ventures with practices that have patients in common (wound clinic, podiatry) will lead not only to better clinical care and better outcomes, but potentially more referrals as well as creating other collaborative efforts (diabetic foot wounds, critical limb ischemia, etc).

Post author
Carlos J. Guevara, MD, FSIR
Assistant Professor of Radiology and Surgery
Division of Interventional Radiology
Mallinckrodt Institute of Radiology, St Louis, MO
@CarlosGuevaraIR

Monday, February 3, 2020

Endovascular Treatment of Complex Aneurysms with the Use of Covera Stent Grafts 


Clinical Question

To characterize the short-term results of the Covera stent for the reconstruction of target vessels in complex aneurysms and assess the safety and efficacy of this stent.

Take-away Point
The Covera self-expanding stent offers good short term patency in chimney, branched, and fenestrated EVAR procedures.

Reference
Caradu C, Dubourg A, Colacchip E, Midy D, Bérard X, Ducasse E. (2019). Endovascular Treatment of Complex Aneurysms with the Use of Covera Stent Grafts. J Vasc Interv Rad, 30:1942-1948. doi:10.1016/j.jvir.2019.05.004

Click here for abstract

Study Design
Nonrandomized, monocentric single-arm evaluation study

Funding Source
None

Setting
Dept of Vascular Surgery, Université de Bordeaux, France; Dept of Vascular Surgery, University Hospital of Poitiers, France; University Hospital of Padova, Italy




Figure 3. (a) Preoperative CT angiogram of an 84-year-old male patient showing a 60-mm type 3 thoracoabdominal aneurysm treated by using (b) a sandwich technique, with covered chimneys constructed using a self-expanding covered stent for the celiac trunk, the superior mesenteric artery, and both renal arteries. (c) The contrast-enhanced CT scan shows the positioning of the 4 self-expanding covered stents positioned between the 2 thoracic devices. (d) 3D reconstruction confirms the positioning of the devices and the preserved patency of the target arteries.

Summary


This single-center study assesses the safety and efficacy of the new Covera self-expanding stent for the use of chimey EVAR, branched EVAR (B-EVAR) and fenestrated EVAR (F-EVAR). It is a retrospective review of 17 patients treating 51 arteries (2.8 ± 1 per patient); 25 arteries were preserved using the Covera stent. Breakdown includes EVAR with hypogastric preservation (11.8%), B-EVAR (29.4%), F-EVAR (17.6%), chimney plus F-EVAR (11.8%) and chimney EVAR (29.4 %). This stentgraft employs a new delivery system minimizing foreshortening which may potentially lead to improved device placement accuracy. The stent has a nitinol structure lending itself to high flexibility and kink resistance, ideal for sharp angulations.

Intraoperative aneurysm occlusion was successful in 82.4% of patients; 2 gutter leaks, 1 type I endoleak, 6 type 2 endoleaks and 1 type 3 endoleak. Over the 10 ± 5-month observation period in this study, there was no evidence of target vessel occlusion. Two secondary procedures were required to address endoleak: a gutter endoleak and a type 3 endoleak in a fenestrated device.


Commentary 


The Covera stent is a new device on the market which offers alternative stent options to the Viabahn or VBX for chimney, fenestrated or branched EVARs. This retrospective study demonstrates similar success rates comparable to those in the reported literature. The flexible and kink-resistant delivery system makes this stent ideal for the extremely tortuous aorta or iliac system. While the study is limited in nature give the small sample size, retrospective nature, and short term follow-up, it does present promising results on the use of the Covera stent.

Post Author
Nicole A. Keefe, MD
Fellow, Interventional Radiology
Department of Radiology and Medical Imaging
University of Virginia
@NikkiKeefe

Monday, January 27, 2020

Radioembolization-Induced Chronic Hepatotoxicity: A Single-Center Cohort Analysis

Clinical question
What are the delayed effects of transarterial radioembolization on the liver?

Take-away point
13% of patients were noted to have delayed radiation-induced hepatotoxicity with tumor involving more than 50% of the liver and cirrhosis as notable predisposing factors.

Reference
Brian M. Currie, et al. Radioembolization-Induced Chronic Hepatotoxicity: A Single-Center Cohort Analysis. Journal of Vascular and Interventional Radiology. Dec, 2019: 30; 12, 1915-1923.

Click here for abstract

Study design
Retrospective

Funding source
Self-funded or unfunded

Setting
Single-center





Table 6. Demographics and Treatment Details: Subset Analysis

Summary


Radioembolization-induced liver disease (REILD) is defined as jaundice and/or ascites occurring within the first one or two months and resolving by 6 months following radioembolization in the absence of tumoral progression or biliary obstruction. This study attempted to define criteria that develop outside of this window. The study included all patients status post radioembolization between 2005 and 2014 and survived a year. All malignancies were included with 54% neuroendocrine tumor, 16% hepatocellular carcinoma, and 14% colorectal cancer. Radioembolization procedures were performed with both Sirspheres and Theraspheres.

The authors defined a classification system called radioembolization-induced chronic hepatotoxicity (RECHT) to be clinically distinct from radioembolization induced liver disease (REILD) and radiation induced liver disease (RILD). In RECHT, toxicity occurs 6 months or greater from treatment and must be permanent. Lab criteria included INR, bilirubin, ALT, AST, alkaline phosphatase, albumin, and platelets and were classified from grade 1-4 based on CTCAE classification. Clinical toxicity criteria included hepatic necrosis, hepatic failure (encephalopathy), portal hypertension (varices), ascites, and portal vein thrombosis and were classified grade 3 or 4. The authors defined RECHT as any new and permanent Grade 3 or 4 clinical and laboratory hepatotoxicity that could not be attributed to disease progression or other factors.

While 50% of patients had chronic hepatotoxicity, only 13% were classified as RECHT. The remaining were excluded due to disease progression, additional therapies complicating the clinical picture, or REILD. 92% of patients with RECHT had clinical complications. 5% of all patients and 36% of patients with RECHT died.

Using univariate and subgroup analysis, tumoral burden (greater than 50%) and cirrhosis were found to be predisposing factors for developing RECHT. Notably, patients who developed RECHT received on average a lower radiation dose. 

Commentary


A major difficulty with many radioembolization papers is heterogeneity and incomplete dosing information. This paper is no exception with their 98 patients including both glass and resin microspheres, 13 different primary malignancies represented, and a spectrum of laboratory and clinical toxicities were noted to quality for RECHT. That being said, the goal was to create an all encompassing definition for a toxicity that many IRs have experienced but did not fit into the standard definition of REILD, and the authors succeeded. Unsurprisingly, high tumoral burden and background baseline liver disease were noted to be risk factors for RECHT. This also speaks to the view that radioembolization may be better served earlier in a disease process than as salvage therapy.

Post Author:
David M Mauro, MD
Assistant Professor
Department of Radiology, Vascular and Interventional Radiology
University of North Carolina
@DavidMauroMD

Friday, January 24, 2020

Neutrophil/Lymphocyte Ratio Predicts Increased Risk of Immediate Progressive Disease following Chemoembolization of Hepatocellular Carcinoma


Clinical question

Do patients with hepatocellular carcinoma (HCC) and elevated neutrophil/lymphocyte ratio (NLR) have a greater risk of progressive disease following initial transarterial chemoembolization (TACE)?

Take-away point
Elevated baseline NLR is associated with higher rates of HCC tumor progression at 2-month follow-up imaging after TACE.

Reference
Cruz, J et al. Neutrophil/Lymphocyte Ratio Predicts Increased Risk of Immediate Progressive Disease following Chemoembolization of Hepatocellular Carcinoma. Journal of Vascular and Interventional Radiology, Volume 30, Issue 12, 1887 – 1892.

Click here for abstract

Study design
Retrospective review

Funding source
Self-funded or unfunded

Setting
Single institution





Summary


As an indicator of inflammation, serum neutrophil to lymphocyte ratio (NLR) is being increasingly utilized as a prognostic marker for a variety of disease states. As the survival for locoregional therapies for HCC varies widely, the authors of this study looked at NLR to determine a potential association with disease progression after TACE.

The authors reviewed 190 patients who underwent 254 TACE procedures. TACE was performed with both lipiodol-based conventional technique and drug-eluting embolics (DEB) and followed with CT or MRI 2 months following treatment to assess response using mRECIST. Treatment outcomes did not differ between conventional TACE and DEB-TACE. Thirty-nine patients developed progressive disease at the 2 month follow up imaging study. Mean NLR for this group was 4.1, compared to 2.76 or less for patients with complete response, partial response, or stable disease. Regression analysis showed that NLR and the presence of more than 1 tumor were predictive of mRECIST progression whereas age, liver function, tumor size, and cause of cirrhosis did not predict response (or progression). If one were to use NLR of 3.5 as a cutoff, objective response was achieved in 74% of treatments with NLR <3.5, compared with 52% with a higher NLR. Disease control was also significantly higher in patients with an NLR <3.5 (87% vs 76%; P = .002 by chi-squared analysis).

Commentary


In the era of personalized medicine, this study provides prognostic information for our oncology patients and allows us to better determine which patients might respond best to our therapies. NLR is being actively investigated for its prognostic impact and role in a variety of conditions, including colorectal and prostate cancer, patients undergoing transcatheter aortic valve replacement, atrial fibrillation, and even psychosis (1-5). As such, it is no surprise that an inflammatory environment has implications for our treatments. This study showed that elevated baseline NLR is associated with higher rates of HCC progression at 2 month follow-up after TACE. The authors acknowledge that the relationship between NLR and tumor multiplicity, tumor markers, and Child-Pugh score still needs to be further elucidated. However, this work is a good early step in understanding the role NLR plays in HCC patients.

Post-Author:
Zagum Bhatti, MD
Assistant Professor
Department of Radiology, Interventional Radiology Division
University of Texas Health Science Center at Houston, Houston, TX
@ZagumBhatti

Monday, December 16, 2019

Safety and Efficacy of Sacroplasty for Sacral Fractures: A Systematic Review and Meta-Analysis


Clinical Question
What is the safety and efficacy of sacroplasty for the treatment of osteoporotic and malignant sacral fractures?

Take-Away Point
Sarcoplasty is a safe procedure for treating painful sacral insufficiency fractures resulting from osteoporosis or metastasis and reduces patient pain scores up to a year post-procedure.

Reference
Chandra, Vishnu et al. Safety and Efficacy of Sacroplasty for Sacral Fractures: A Systematic Review and Meta-Analysis. Journal of Vascular and Interventional Radiology, Volume 30, Issue 11, 1845 - 1854.

Click here for abstract

Study Design
Systematic review and meta-analysis

Funding Source
Self-funded or unfunded

Setting
Multi-center







Summary

Sacral insufficiency fractures (SIFs) are a common and growing cause of lower back pain in the elderly population and are often a result of osteoporosis or metastatic spread to the sacrum. Standard therapies consist of conservative management with rest, analgesia, and physical therapy. They are associated with deconditioning, deep venous thrombosis/pulmonary embolism, and psychiatric disease. Sarcoplasty is an evolving minimally-invasive therapy aimed at reducing patient pain due to SIF and allowing improved quality of life and function.

In this meta-analysis and systematic review, 19 retrospective and prospective case series were analyzed for a pooled cohort of 861 patients undergoing 867 procedures. Patients all had sacral insufficiency fractures, with 664 secondary to osteoporosis, 67 to malignancy, and 30 non-specified. Included studies measured pre- and post-procedural pain via the visual analog scale (VAS) as reported by the patient prior to and up to 18 months after sarcoplasty. Complications of the procedure and follow-up treatment were also measured.

VAS scores at pre-procedure, 24–48 hours, 6 months, and 12 months yielded cumulative pain scores of 8.35 ± 0.14 (n=861), 2.70 ± 0.26 (n=749), 2.26 ± 0.24 (n=352), and 2.01 ± 0.34 (n=357), respectively. There was no significant difference in mean pain scores between patients with osteoporotic SIFs and patients with SIF secondary to metastatic disease at any time point. Clinical success (defined as patient-reported pain relief) occurred in 623 of 651 (95.7%) of cases where post-procedural clinical status was evaluated.

Cement leakage was reported in 19 of 867 cases (2.2%), which resulted in clinical symptoms in 5 patients. 3 of these required surgical decompression while 2 were treated successfully with conservative management. No other complications, including infection, bleeding, or pulmonary embolism were reported.

Commentary

In this meta-analysis and systematic review, sarcoplasty was shown to be safe and effective at relieving patient pain up to a year from the procedure. Other outcomes, such as patient functional status, mobility, satisfaction, or use of pain medications (such as opioids) were not measured. Future investigations should compare sarcoplasty versus sham and conservative therapies in the form of randomized controlled trials, while future retrospective studies should measure the long-term efficacy and safety of sarcoplasty as well as the use of opioids and patient functional status.
 
Post Author

Jared Edwards
4th Year Medical Student
Oregon Health & Science University School of Medicine, Portland, OR

Friday, December 13, 2019

Percutaneous Costoclavicular Bypass for Thoracic Outlet Syndrome and Cephalic Arch Occlusion in Hemodialysis Patients

 
Clinical Question
Report results of percutaneous costoclavicular bypass for symptomatic thoracic outlet or cephalic arch occlusion in patients with arteriovenous fistula.

Take-Away Point
Percutaneous costoclavicular bypass is a feasible option for thoracic outlet and cephalic arch occlusion in symptomatic dialysis patients.

Reference

Hull, J. and J. Snyder (2019). "Percutaneous Costoclavicular Bypass for Thoracic Outlet Syndrome and Cephalic Arch Occlusion in Hemodialysis Patients." J Vasc Interv Radiol 30(11): 1779-1784.

Click here for abstract

Study Design
Retrospective chart review of patients undergoing percutaneous costoclavicular bypass.

Funding Source

No reported funding

Setting
Richmond Vascular Center, North Chesterfield, VA






Figure 1. Key steps of costoclavicular bypass.

Summary


Intravascular treatment of venous outflow stenosis in patients with thoracic outlet syndrome and cephalic arch pathology has been limited by external compression at the costoclavicular junction. Subcutaneous costoclavicular bypass is a minimally invasive alternative to surgical decompressive options such as first rib resection and claviculectomy.

A retrospective chart review of 9 patients undergoing percutaneous costoclavicular bypass was performed. Inclusion criteria comprised patients with ESRD, AV fistula, and symptomatic occlusion of the cephalic arch or subclavian vein with previous failure of standard therapies. One patient received a Gore Hybrid vascular graft, all other cases were performed using Viabahn stent grafts.

The percutaneous costoclavicular bypass was technically successful in 100% of cases. All patients had symptomatic improvement at 1 week. There were no immediate complications. At 12 months and 24 months, primary patency was 67% and 67%. Secondary patency was 89% and 78%. The Viabahn stent graft achieved a hemostatic seal in all cases and the stent grafts remained intact at follow up.

One patient demonstrated stent migration at the fistula outflow, which was treated with overlapping stent graft extension. Loss of costoclavicular bypass occurred in 3 patients. One stent graft was secondarily infected 5 months after placement and was subsequently excised. The Gore hybrid graft kinked and required over-stenting with bare metal and covered stents, leading to graft thrombosis and edge stenosis, and was abandoned after 3 years.

 

Commentary


Percutaneous costoclavicular bypass demonstrates early clinical success in this retrospective study. While this study is limited by the inclusion criteria and small patient population, the patency rates, high technical success rates, and high clinical success rates are promising. Notably, the authors did not report any stent compression, buckling, or deformity. The durability of the Viabahn stent graft opens the door for other potential percutaneous, subcutaneous bypass procedures. While percutaneous costoclavicular bypass shows early clinical success, further research is required to determine success in larger patient populations.

Post Author

Maxwell R. Cretcher, DO
Resident Physician, Integrated Interventional Radiology
Dotter Department of Interventional Radiology
Oregon Health & Science University