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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

Friday, April 5, 2019

Use of Drug-Coated Balloons in Dysfunctional Arteriovenous Dialysis Access Treatment: The Effect of Consecutive Treatments on Lesion Patency


Clinical question
What is the outcome in arteriovenous (AV) access circuits that undergo repeat drug-coated balloon (DCB) angioplasty?

Take-away point
In this retrospective study of AV circuits undergoing consecutive DCB, there was no significant difference in the postintervention primary patency (PIPP).

Reference
Park, Joong-Won, et al. Sorafenib with or without concurrent transarterial chemoembolization in patients with advanced hepatocellular carcinoma: The phase III STAH trial. Journal of Hepatology. December, 2018. In Press.

Click here for abstract

Study design: Retrospective Longitudinal Analysis

Funding source: None identified.

Setting: University hospital setting - Greece.

Summary 


This is a retrospective longitudinal study evaluating the recurrent use of DCB in dysfunctional AV circuits. The authors evaluated 165 patients undergoing 257 procedures. From this cohort, the authors then selected the 38 patients who had a single lesion treated at minimum 2 times with a DCB. They then evaluated from this study population the postintervention primary patency (PIPP), with the goal to evaluate noninferiority of the second (repeat) intervention. 22/38 patients underwent two treatments with DCB, the remaining ranging from 3-6 treatments. The most common treatment site was cephalic vein. The authors concluded the use of repetitive DCB was safe from an AV access circuit standpoint and that recurrent use was noninferior to the first use with regard to PIPP. The authors did note that there was a significant increase in PIPP in patients undergoing a total of two interventions, favoring the second intervention (N= 22 for this population).


Commentary


This is a retrospective study with a relatively small number of patients that evaluates the use of repeat DCB in dysfunctional AV circuits. The authors noted that repeat use of DCB on the same lesion did not result in inferior primary patency rates. They did note a significant trend towards increased postintervention primary patency in patients who required a total of two interventions over the study period. This study suggests that consecutive DCB is safe with regard to the patency of the access circuit. However, given the recent literature surrounding overall risk regarding the use of DCB, it is unclear to me the impact on clinical practice change this article will have.

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

Friday, March 15, 2019

Safety and durability of infrarenal aorta as distal landing zone in fenestrated or branched endograft repair for thoracoabdominal aneurysm 


Clinical Question:
Does using the infrarenal aorta as a distal landing zone, instead of iliac arteries, for fenestrated or branched endovascular aortic repair (FB-EVAR) decrease the rate of spinal cord and mesenteric ischemia?

Take-away Point:
Termination of an aortic endograft in the infrarenal aorta for fenestrated and branched EVAR is technically feasible with similar rates of paraplegia and mesenteric ischemia however more data is needed to evaluate for future type 1B endoleaks due to aortic degeneration.

Reference:
Law Y, K├Âlbel T, Rohlffs F, Behrendt C, Heidemann F, Debus ES, Tsilmparis N. (2018). A Safety and durability of infrarenal aorta as distal landing zone in fenestrated or branched endograft repair for thracoabdominal aneurysm. J Vasc Surg, 69(2), 334-341. doi:10.1016/j.jvs.2018.04.052

Click here for abstract

Study Design: Retrospective single-center cohort study

Funding Source: Self-funded

Setting: Department of Vascular Medicine, German Aortic Center Hamburg, University Heart Center of Hamburg, Germany

Summary


Conventional knowledge and manufacturer recommendation supports use of the iliac arteries as the distal landing zone for fenestrated and branched endovascular aneurysm repair (FB-EVAR) however there is no data in the literature to support iliac over distal aorta landing zone. This study retrospectively evaluated 40 patients who received FB-EVAR with the native infrarenal aorta as the distal landing zone. Grafts included the Zenith custom-made, Zenith T-branch and surgeon-modified endografts. Criteria for use of the infrarenal aorta included ≥2 cm of healthy infrarenal aorta, preferably free of thrombus, dissection and calcification. The distal stent graft was oversized by 15-30% diameter; in the event of a severe size mismatch of the distal stent graft modules a Giant Palmaz stent was placed to correct infolding and strengthen the connection.

No immediate or delayed type 1B endoleaks (range 0-72 months) were identified on surveillance CTA. Spinal cord ischemia occurred in 15% of patients (5 temporary and 1 permanent) and zero incidence of mesenteric ischemia, both of which are comparable to literature with iliac distal landing zones. 30-day mortality was 7.5% (sepsis, pneumonia, and multiorgan failure following laparotomy for GDA bleed). Post-operative CTA showed that 92.5% had at least 1 lumbar artery preserved and 74.2% had the IMA preserved. Of note, there was gradual degeneration of the infrarenal aorta at the stent graft landing zone, likely attributable to the aorta expanding to the size of the stent graft from the outward radial force. 


Figure 4. Denervation of infrarenal aorta and iliac arteries over time. The averaged nominal diameter of stent grafts was indicated. The error bars indicate the 95% confidence interval (CI).

Commentary


Termination of the stent graft in the infrarenal aorta for FB-EVAR is technically feasible with similar paraplegia and mesenteric ischemia rates to current reported literature on iliac landing zones. While the rates of paraplegia and mesenteric ischemia reported by the authors are comparable, they question whether their rates may be higher due to a high proportion of emergent cases. Preserving the IMA and lumbar arteries intuitively would minimize this risk. Degeneration of the infrarenal aorta at the site of the stent graft however appears problematic for younger patients as they will likely need distal extension for future type 1B endoleaks. Infrarenal aortic landing zone seems best suited for those patients at highest risk for paraplegia (long total coverage area, prior repair, etc) and mesenteric ischemia. Further work is needed however with comparison studies and longer term follow-up to determine the viability of this treatment option.

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

Thursday, March 14, 2019

Clinical and Economic Benefits of Stent Grafts in Dysfunctional and Thrombosed Hemodialysis Access Graft Circuits in the REVISE Randomized Trial 


Clinical question
Is it more efficient and cost effective to maintain arteriovenous graft hemodialysis access circuits after rescue with percutaneous transluminal angioplasty with or without concurrent Viabahn stent grafts over 24 months?

Take-away point
Over 24 months, the use of stent grafts significantly reduced the number of reinterventions for all patients and reduced overall treatment costs for patients presenting with thrombosis.

Study design:
Prospective Randomized Control Study

Funding source:
W. L. Gore & Associates Inc. (Flagstaff, Arizona).

Setting:
Multicenter trial

Citation: 
Mohr, Belinda A. et al. Clinical and Economic Benefits of Stent Grafts in Dysfunctional and Thrombosed Hemodialysis Access Graft Circuits in the REVISE Randomized Trial. Journal of Vascular and Interventional Radiology , Volume 30 , Issue 2 , 203 - 211.e4


Summary


Arteriovenous grafts (AVGs) are an important option for patients on hemodialysis. Unfortunately, AVGs are susceptible to complications that can lead to reinterventions, increased costs and ultimately graft failure/abandonment. The conventional approach for failing grafts related to venous anastomotic stenoses has been percutaneous transluminal angioplasty (PTA). Recently stent grafts (SGs) have emerged as a promising supplemental approach to revising dysfunctional or thrombosed AVGs. In this study, inclusion criteria were patients with an AVG > 30 days old that was dysfunctional or thrombosed with a primary lesion having >50% stenosis and < 30 mm from the venous anastomosis. Patients were split into four groups with either dysfunctional/stenotic or thrombosed grafts and were treated with PTA alone or PTA with SG.

Overall, patients in the SG arm required significantly fewer total reinterventions compared to the patients in the PTA arm and the mean time to reintervention with SG vs PTA was 203 to 108 days. Specifically, patients with thrombosed AVGs treated with SG required 40% less reinterventions of any kind compared to those treated with PTA alone. Patients with graft dysfunction/stenosis initially treated with SG resulted in 16% less reinterventions compared to PTA, which was not statistically significant. Reintervention with PTA was reduced by 44% in patients presenting with thrombosed circuits who were treated with SG (statistically significant). Dysfunctional grafts had reduced PTA reintervention by 17% when the index procedure was augmented with SG (not statistically significant). Thrombosed grafts at presentation resulted in significantly more interventions overall, particularly more thrombectomy/thrombolysis procedures. SG placement in thrombosed grafts reduced future thrombectomy/thrombolysis by 36%.

When randomized by treatment, SG costs were 4% lower than initial PTA alone at 24 months although this was not statistically significant. However, when randomized by presentation, treatment of thrombosed grafts with SG reduced costs by 18% compared to PTA at 24 months. There was no significant cost difference between the two treatment groups with purely stenotic AVGs.



Figure 1
Stent graft placement significantly reduced total reinterventions over 24 months. Subgroup presentation show that reinterventions were significantly reduced at 24 months when thrombosed grafts were treated with stent grafts. Stent graft also decreased reinterventions in dysfunctional grafts, though not significantly. Cost was only statistically significantly reduced when stent grafts were used to treat thrombosed grafts.

Commentary


Maintaining patent vascular access in ESRD patients is an obstacle that has proven to be fraught with difficulties and frustration for both patients and providers. These challenges inevitably translate into multiple vascular interventions and increased healthcare costs. The REVISE trial has demonstrated that AVGs treated with angioplasty and SG placement can reduce subsequent reinterventions and cost over 24 months, most significant in thrombosed circuits. Given that there are an estimated 457,957 ESRD patients on hemodialysis, consistently reducing reintervention would dramatically decrease the overall healthcare cost. The trial calculated that SG placement could reduce cost by $6,877 for each patient with a thrombosed AVG over two years. This would result in millions of dollars saved if even a small portion of the total ESRD population were treated with SG. Cost savings were contingent upon AVG survival to 2 years as initial upfront costs were expectedly higher with SG placement. This trial specifically looked at AVGs, and there is a larger prevalence of patients who receive dialysis via arteriovenous fistulas (AVFs). A similarly structured trial focused on AVFs and central stenoses could further evaluate initial intervention options and the subsequent effect on reinterventions and cost with AVFs. This could potentially lead to findings that would have larger cost savings to the system.

Post Author:
Bradley Unruh, MD PGY-3
Department of Radiology
Wake Forest Baptist Medical Center
@WakeForest_IR