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Monday, August 19, 2019


Safety and Efficacy of Radiofrequency Ablation for Nonfunctioning Benign Thyroid Nodules in Children and Adolescents in 14 patients over a 10-Year Period


Clinical question
Is it safe and effective to perform radiofrequency ablation for nonfunctioning benign thyroid nodules in children and adolescents?

Take-away point
RFA is likely safe and effective for the treatment of nonfunctioning benign thyroid nodules in children and adolescents

Reference
Min Ji Hong, et al. Safety and Efficacy of Radiofrequency Ablation for Nonfunctioning Benign Thyroid Nodules in Children and Adolescents in 14 patients over a 10-Year Period. Journal of Vascular and Interventional Radiology. Jun3, 2019: 30; 6.

Click here for abstract

Study design
Retrospective

Funding source
Self-funded or unfunded

Setting
Single-center








Figure 1A 17-year-old female patient with a palpable nonfunctioning thyroid mass.

Summary

Currently, surgery is the preferred treatment method for pediatric thyroid nodules. Radiofrequency ablation (RFA) is rising in popularity for treatment of adult benign thyroid nodules. Ablation may be able to avoid risks associated with thyroid surgery, including hypothyroidism and vocal cord palsy, while still being able to reduce compressive and cosmetic problems caused by a benign nodule. This study evaluated a single center’s experience with using RFA in 14 pediatric patients.

All patients underwent biopsy to confirm benign pathology and had pressure symptoms or cosmetic problems secondary to the thyroid nodule. Ablation was performed with local anesthesia with ultrasound guidance using an 18-gauge 7 cm probe with a 0.5, 1, or 1.5 cm tip (Well-Point RF Electrodes). A moving shot technique was utilized, by placing the tip at the deepest portion of the nodule and withdrawn to the superficial aspect. A mean number of 2.1 treatment sessions were performed and no major complications were encountered. Over the mean follow up period of 36.9 months, the average nodule size was reduced from 3.7 cm pre-procedure to 1.7 cm on final follow up. Symptom and cosmetic scores were also significantly reduced from baseline. There was no significant change in serum thyroid levels.

Commentary

This is the first study evaluating ablation of benign nonfunctioning thyroid nodules in the pediatric population. While small in size, the study did demonstrate efficacy and safety. RFA may prove to be a preferred treatment for many benign nodules over surgery as it avoids hypothyroidism and minimizes the risk of recurrent laryngeal nerve damage. Additional benefits include avoidance of general anesthesia and absence of an incisional scar. A larger cohort would be needed to determine true complication rate, especially if performed by less experienced physicians. Thyroid ablation continues to be a growing field with numerous possible applications in the future.

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

Monday, August 12, 2019

Muscle Gain after Transjugular Intrahepatic Portosystemic Shunt Creation: Time Course and Prognostic Implications for Survival in Cirrhosis


Clinical question
Is transjugular intrahepatic portosystemic shunt (TIPS) placement associated with truncal muscle gain and potentially improved mortality?

Take-away point
TIPS resulted in truncal muscle gains, seen maximally at 6 months after shunt placement. At one year, muscle gain was independently associated with decreased mortality.

Reference
Jahangiri Y, et al. Muscle gain after transjugular intrahepatic portosystemic shunt creation: time course and prognostic implications for survival in cirrhosis. J Vasc Interv Radiol. 2019 Jun; 30(6): 866-872.

Click here for abstract

Study design
Retrospective review

Funding source
None identified

Setting
University hospital setting – Oregon, United States.






Table 2
Comparison of Cross-Sectional Truncal Muscle Area and Attenuation by CT before and after TIPS at a Median 13.5 Months after TIPS


Summary

This is a retrospective review of a cohort of patients who underwent TIPS at a single institution over a 12 year period. Only patients with native livers who had pre and post CT imaging were included (N=76). The authors then evaluated core abdominal muscles in three regions: psoas, paraspinal, and abdominal wall musculature. Volumes as well as attenuation of these muscle groups were then calculated before and after TIPS. The authors found statistically significant gains in both volume and attenuation of the truncal musculature after TIPS, with maximal increase at approximately 6 months. These volume gains were also found on multivariate analysis to be associated with lower mortality.


Commentary

This retrospective study increases the body of literature regarding the association of core muscle mass with overall survival in cirrhotic patients. In addition, it also supports that TIPS creation may help, either directly or indirectly, allow patients to improve their muscle mass. The limitations of this article are its study design and relatively small number of patients. That said, statistical significant was achieved on multivariate analysis. The study also improves the knowledge regarding the time frame of the muscle gains in patients undergoing TIPS.

Post Author
Daniel P. Sheeran, MD
Assistant Professor
Department of Radiology and Medical Imaging
Division of Vascular and Interventional Radiology
University of Virginia

Monday, August 5, 2019

iCAST Balloon-Expandable Covered Stent for Iliac Artery Lesions: 3-Year Results from the iCARUS Multicenter Study



Clinical Question
To evaluate the safety and efficacy of the iCAST Covered Stent for the treatment of iliac artery atherosclerotic lesions



Take-away Point
The iCAST balloon-expandable stent was found to be a safe and effective treatment for iliac atherosclerotic lesions with PPR of 96% at 9 months, and clinical improvement in 72.4% at three years. 



Reference
Laird J, Loga M, Zeller T, Naizi K, Foster M, Ansel G, Stone D, Dave R, Popma J, Jaff M, Massaro J. (2019). iCAST Balloon-Expandable Covered Stent for Iliac Artery Lesions: 3-Year Results from the iCARUS Multicenter Study. J Vasc Interv Rad. 30, 822-829. Doi:10.1016/j.jvir.2018.12.707




Study Design 
Single-arm, prospective, multicenter study



Funding Source
Sponsor Atrium Medical Corporation



Setting
24 US cities and 1 German center





Table 4

Subject-Based Secondary Outcomes in Per Protocol Population.


Summary

The iCARUS trial enrolled 165 subjects at 25 different sites, ultimately having 152 subjects with 223 lesions meet inclusion criteria. This included Rutherford class 2-4, stenotic lesions in the common or external iliac arteries <110 mm in length and 5-12 mm in diameter with ≥50 stenosis with concurrent patent profunda or SFA. Baseline ABI of 0.73 ± 0.23 was noted with a total occlusion rate of 17.1%. Primary endpoint was a compositive of the occurrence of death within 30 days, target lesion revascularization (TLR) within 9 months or restenosis of the iliac on US or angio at 9 months. 

264 iCAST stents were implanted with mean percent reduction in stenosis from 69.3 ± 16.7% to 2.5 ± 5.7%. Device success was 98.7% with a 9-month, 2-year and 3-year clinical success rate of 76.6%, 70.8% and 72.4% respectively. There was a 9-month primary patency rate of 96.4%. Two patients had device nonsuccess; one was due to delivery balloon rupture and the other the stent dislodged from the balloon, was removed, and replaced with another stent. 

The iCAST balloon-expandable stent was found to be a safe and effective treatment for iliac atherosclerotic lesions with satisfactory 9-month primary patency and sustained clinical improvement with low TLR up to three years. 


Commentary

While studies funded by device companies must be taken with a grain of salt, the iCARUS data shows promising clinical performance up to three years post intervention. It does not have ultrasound or angiographic imaging past 9 months which somewhat confounds the information as patients could have developed in stent stenosis or occlusion while developing collateral vessels. Of note, the baseline ABI of 0.73 seemed relatively high, perhaps indicating that the patients within the study already had a fair degree of collateralization, which may mask late stenosis of the stent.

Other studies such as the COBEST trial compared the iCAST stent (marketed as Advanta V12 outside of the US) to bare metal stents for TASC C and D lesions and demonstrated superiority in patency and clinical outcomes. The forthcoming DISCOVER trial which randomizes covered and uncovered balloon-expandable stent use in the CIA will should allow direct comparison of the iCAST to uncovered stents, further clarifying its use in clinical management of CIA and EIA stenosis. 


Post Author

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

Friday, July 19, 2019

Downstaging Prior to Liver Transplantation for Hepatocellular Carcinoma: Advisable but at the Price of an Increased Risk of Cancer Recurrence – A Retrospective Study


Clinical question Does the original HCC stage have an impact on post-transplant outcome after successful downstaging?

Take-away point 
Despite an increase in post-transplant HCC recurrence in downstaged patients, similar survivals can be achieved to patients who do not require downstaging. Therefore, downstaging should be continued to be performed.

Reference
Toso, Christian et al. “Downstaging Prior to Liver Transplantation for Hepatocellular Carcinoma: Advisable but at the Price of an Increased Risk of Cancer Recurrence - a Retrospective study.(Report).” Transplant International 32.2 (2019): 163–172.

Click here for abstract

Study design: Retrospective review

Funding source: Self-funded or unfunded

Setting: Multi-institution 

















Figure 1. Disease-free survival according to downstaging based on TTV115/AFP400 (47% versus 80% at 5 years, =0.95).

Summary

Studies have shown that patients with advanced HCC can benefit from transplantation after downstaging, however, most of these studies used Milan criteria as the downstaging goal and most of the patients were marginally outside of Milan criteria. The authors of this retrospective review of a prospectively maintained database of patients from 2 institutions included patients within the total tumor volume (TTV)/alpha fetoprotein (AFP) criteria (TTV <115 cm3 and AFP < 400 ng/mL; included approximately 20% more patients compared to Milan criteria) and those with advanced HCC but who were successfully downstaged to and stable within this criteria for 3 months. 455 patients were listed for transplantation, 286 of whom were transplanted according to the TTV115/AFP400 criteria. 257 of the transplanted patients underwent a locoregional HCC treatment prior to transplantation which included TACE, RFA, alcohol ablation, SIRT, and resection. TACE, RFA, and alcohol ablation were the most commonly performed procedures. 29 patients were successfully downstaged. Downstaged patients demonstrated similar disease-free survivals (DFS, 74% vs. 80% at 5 years, P = 0.949), but a trend to more recurrences (14% vs. 5.8%, P = 0.10) than those always within TTV115/AFP400 criteria. Similarly, patients downstaged to Milan criteria (n = 80) demonstrated similar DFS (76% vs. 86% at 5 years, P = 0.258), but more recurrences (11% vs. 1.7%, P = 0.001) than those always within Milan (n = 177). Of note, patients treated by RFA or microwave ablation versus TACE prior to transplantation showed showed similar DFS (78.9% vs. 77.2% at 5 years, P = 0.74), and similar rates of post-transplant HCC recurrence (4/73, 5.5% vs. 13/164, 7.9%, P = 0.50).

Commentary

This paper suggests that patients with advanced HCC outside of expanded transplant criteria should have hope of achieving similar survival after transplantation compared to patients with lower AFP. The higher risk of recurrence is modest (~11%) and it does not appear that this should impact the decision to offer transplant versus palliation only for advanced HCC patients. Further study will need to be performed to determine which patients would benefit most from downstaging, especially considering the relatively small number of patients who were ultimately downstaged, but these results are promising for those patients for whom downstaging is successful.

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

Friday, July 12, 2019

The Role of Simulation in Boosting the Learning Curve in EVAR Procedures 


Clinical Question
Does the use of simulator training for endovascular procedures, specifically EVAR, improve trainees quantitative and qualitative performance?

Take-away Point
Simulation training has the potential to alter the paradigm with which we teach IR trainees from one of apprenticeship to one that is a hybrid of simulator training and mentor training.

Reference
Vento V, Cercenelli L, Mascoli C, Gallitto E, Ancetti S, Faggioli G, Freyrie A, Marcelli E, Gargiulo M, Stella A. (2018). The Role of Simulation in Boosting the Learning Curve in EVAR Procedures. J of Surg Edu, 75(2), 534-540. Doi:10.1016/j.jsurg.2017.08.013 

Click here for abstract

Study Design: Cohort Blinded Study

Funding Source: Self-funded

Setting: Vascular Surgery, Department of Experiment Diagnostic and Specialty Medicine, University of Bologna; Bologna, Italy. 


Figure 4. Overall mean qualitative performance: comparison of total performance score (TPS) between the trainee group (blackline) and the control group (gray line) at t0 and t1.

Summary

Conventional teaching in medicine is through an apprenticeship model however this is outdated and inadequate for training endovascular specialists of the new generation. Simulator training provides an opportunity to teach trainees prior to performing the procedure on a real patient. This study took 10 vascular surgery residents of varying levels and randomized them into two groups: control and trainee. Each group performed 2 simulated EVAR procedures (basic and complex) at time point 0 and again 2 weeks later. The trainee group additionally performed 6 simulated EVAR procedures over the two weeks, all with the Gore Excluder stent graft. Trainees were evaluated on total procedure time (T­P), total fluoroscopy time (TF), total contralateral gate cannulation time (TG), and contrast medium volume (CM). The qualitative evaluation was based on seven performance criteria including: respect for tissue, handling of endovascular material, knowledge of the tools and procedure, planning, performance, and quality of the final product.

The trainee group significant reduced their TP (48 min ± 12 vs 32 ±8), TF (18 min ± 7 vs 11 ± 6) and CM (121 cc ± 37 vs 85 ± 26); TG was not significantly changed. The control group did not significantly change between the pre- and post-sessions. The trainee group also significantly improved their qualitative score (13.3 ± 5.8 vs 25.4 ± 5.3) while the control group did not. This study demonstrates that both junior and senior residents in endovascular fields can benefit from simulator training for EVAR procedures.

Commentary

Simulator training has played a role in training throughout many different professions including pilots and astronauts; this method is translatable to interventional radiology as technology improves and the ability to make real-life simulators develops. Many different departments have simulators for vascular access, be it a chicken with an olive under the skin or an actual mannequin. Advances in technology have now allowed us to create more complex simulators including ones in which real patient information can be input. The use of the simulators has the potential to significantly alter the way IR residents are trained, shifting from an apprenticeship method to one that includes both simulator training and mentor training. Not only is this applicable to EVAR but it can be extrapolated to include ablations, TIPS, vessel selection, aneurysm coiling; the possibilities are endless. Simulator training also affords a better experience for trainee, attending and patient alike if the trainee has improved confidence and skill when performing the procedure. We must, however, also demonstrate that the skills learned in the sim lab translate to those performed in the IR suite.

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

Friday, June 21, 2019

Ultrasound-guided Microwave Ablation for the Management of Inguinal Neuralgia: A Preliminary Study with 1-Year Follow Up


Clinical question 
Is MWA effective in treating post-surgical inguinal neuralgia.

Take away point
MWA was able to treat chronic inguinal neuralgia in short and medium term without adverse outcomes.

Study design 
Retrospective review of 12 procedures (10 patients)

Funding Source 
No reported funding.

Setting
Academic hospital, University of Wisconsin School of Medicine and Public health.

Click here for abstract

Summary
Inguinal neuralgia affects 12% of inguinal herniorrhaphy patients. Patients present with burning or throbbing pain in the groin and proximal and medial thigh. Chronic inguinal neuralgia (> 6 weeks) has limited improvement with oral medication, surgery, nerve blocks etc. This study evaluated the safety and efficacy of microwave ablation (MWA) in the treatment of chronic inguinal neuralgia.

Ten patients (12 procedures) were evaluated retrospectively. Patients included in this study had a positive response to an ultrasound-guided nerve block (steroid and anesthetic) of the ilioinguinal, iliohypogastric or genitofemoral nerve. Patients were considered to have had a positive response if they had a pain reduction score of more than 2 points on the VAS scale for at least 2 hours, and were treated when their pain returned to baseline.

Successful placement of the MW antenna next to the culprit nerve was confirmed by using a short MW pulse that reproduced the patient’s pain. MWA was performed under sedation using 3 cycles of 30 watts for 30 seconds. Phone call follow up was performed at 1, 6 and 12 months using the VAS scores. Clinical success was considered as 2-point decrease in VAS score.

Mean baseline VAS score was 6.1 (SD 2.5), immediately post procedure 2.2 (SD 2.4), at 1, 6 and 12 months, 0.8 (SD 1.5), 1.5 (SD 2.0), and 2.0 (SD 2.7) respectively. Significant pain improvement was seen at all time points, and at 12 month follow up there was significant pain relief in 10/12 procedures, with an average pain relief reduction of 10.5 months. Mean procedure time was 43.3 minutes (range, 20-60 minutes), and no adverse events were observed.

The authors highlight the advantages of MWA over RF, which include faster tissue heating, reproducible treatment zones, less susceptibility to heat-sink, etc. The authors also mention that cryoablation has also been used in the treatment of inguinal neuralgia with 78% clinical success in 10 patients, which make it similar to the results presented in this study. Ultrasound targeting of the nerves allows direct visualization of the nerve when compared to CT that uses landmarks for nerve targeting. Reasons for clinical failure in 2 patients, the authors hypothesize, included the initial targeting of the ilioinguinal nerve, as well as normal anatomical variants that can cause overlap in symptoms between the 3 main nerves involved in inguinal neuralgia.

The main limitations of the study include, retrospective design of the study, lack of control group, and lack of standardized follow up. Regardless of the limitations, this study provides encouraging data that supports the use of MWA for the treatment of inguinal neuralgia. Larger studies, with a control group and longer follow up are needed to validate these findings.


Figure 1- Intra-procedural MWA showing the inferior epigastric artery (red arrow), genitofemoral nerve (arrow head), MWA antenna (arrows), and hernia mesh (curved arrows). 


Commentary 

Currently, patients with post-surgical chronic inguinal neuralgia have limited options with the authors providing data supporting the use of MWA for pain control. Patients included in this study had successful nerve block, which confirmed the culprit nerve. It remains unclear why 1 patient had a positive response to the nerve block and no response to MWA. Ultrasound targeting of the nerve provides a more accurate modality to ensure successful needle placement adjacent to the nerve. Overall, 10/12 procedures showed clinical improvement at 12 months, which is very promising. As the authors mentioned a larger study (with longer follow up) including a control group, and possibly comparison to cryoablation, is necessary to validate MWA as the modality of choice in the treatment of inguinal neuralgia.

Post Author
Carlos J. Guevara, MD, FSIR
Assistant Professor
Department of Radiology, Interventional Radiology Division
University of Texas Health Sciences, Houston
@CarlosGuevaraIR

Monday, April 8, 2019

Proton Pump Inhibitor Use Is Associated with an Increased Frequency of New or Worsening Hepatic Encephalopathy after Transjugular Intrahepatic Portosystemic Shunt Creation


Clinical question
Does proton pump inhibitor (PPI) use increase the rate of new or worsening hepatic encephalopathy (HE) after transjugular intrahepatic portosystemic shunt (TIPS) creation?

Take-away point
PPI usage is associated with new or worsening HE after TIPS.

Reference
Lewis, Douglas S., et al. Proton Pump Inhibitor Use is Associated with an Increased Frequency of New or Worsening Hepatic Encephalopathy after Transjugular Intrahepatic Portosystemic Shunt Creation. Journal of Vascular and Interventional Radiology. February, 2019. Volume 30, Issue 2, 163-169.

Click here for abstract

Study design: Retrospective

Funding source: Self-funded or unfunded

Setting: Single institution

Summary


HE after TIPS remains a common and challenging problem and can result in significant quality of life issues for patients’ refractory to medical therapy.

This retrospective review identified 284 patients who had undergone TIPS over a 1 year period, with a median follow-up time of 479 days. PPI types and dosage, in addition to dates of use were noted through review of the electronic medical record. Dates of new or worsening HE after TIPS were also identified. Mixed-effects negative binomial regression was used to test for an association between PPI usage and HE. The authors reported that, among the 284 patients analyzed in this study, there were 375 episodes of new or worsening HE, for an average of 1.32 episodes per person. Among 168 patients on PPIs chronically, there were 235 episodes of new or worsening HE in 106,101 person-days (0.81 episodes per person-year), 55 patients who were never on PPIs had 37 episodes (0.43/person-year), 61 patients intermittently on PPIs had 78 episodes (0.75/person-year), and 16 patients who never took PPIs had 25 episodes (0.26/person-year). Uni- and multivariate regression were performed. PPI usage was associated with a 3.34-fold increase in the rate of new or worsening HE and increasing age, higher MELD score, and history of HE or HE-preventative medication therapy before TIPS were also associated with increased HE after TIPS.




Commentary


This study showed that PPI usage was associated with a statistically significant increase in the rate of new or worsening HE after TIPS. This is an extremely important finding given how common HE is after TIPS and how debilitating HE can be for patients and their families. Of note, the rate of TIPS coarctation or embolization was not significantly different between those patients who were on PPIs and those who were not. However, we know HE significantly affects quality of life and can be difficult to manage medically. The authors cited a number of reasons the patients they studied were prescribed PPIs, including varices, GE reflux, ulcer disease, etc. Surprisingly, almost 40% of patients had no documented indication for PPI use. Recognizing that PPIs can increase the risk of new or worsening HE in post-TIPS patients should prompt us to carefully consider what medications our patients are taking and to discontinue nonessential PPI therapy.

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