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.

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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

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 

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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

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