Radiofrequency Ablation For Hepatocellular Carcinoma Research Articles

Lusutrombopag Reduces the Risk of Hemoperitoneum Caused by Percutaneous Radiofrequency Ablation for Hepatocellular Carcinoma Compared with Platelet Transfusion.

Patients with liver cirrhosis develop thrombocytopenia and an increased risk of bleeding events after invasive procedures. Lusutrombopag, a thrombopoietin receptor agonist, can increase the platelet count. This study assessed whether lusutrombopag reduces the risk of hemoperitoneum following percutaneous radiofrequency ablation for hepatocellular carcinoma, compared with platelet transfusion. Participants in the present study comprised patients with severe thrombocytopenia (platelet count < 50,000/μL) enrolled between November 2012 and March 2020, excluding patients with idiopathic thrombocytopenia or anticoagulant use. Hemoperitoneum rate, hemostasis rate, hemoglobin reduction rate, rate of achieving a platelet count  50,000/μL, and increases in platelet count and factors contributing to hemoperitoneum were retrospectively analyzed. This study enrolled 41 patients, comprising 18 patients administered lusutrombopag and 23 patients who received platelet transfusion. The major hemoperitoneum rate after RFA was tend to lower in the lusutrombopag group (0%) than in the platelet transfusion group (21.7%). All of the major hemoperitoneum was observed in the platelet transfusion group. Hemoglobin reduction rate was lower in the lusutrombopag group (-0.17%) than in the platelet transfusion group (6.79%, P = 0.013). Hemostasis rate was lower in the lusutrombopag group (0%) than in the platelet transfusion group (21.7%, P = 0.045). The rate of achievement of a platelet counts  50,000/μL the day after RFA was higher in the lusutrombopag group (100%) than in the platelet transfusion group (60.9%, P = 0.005). Lusutrombopag may be able to perform RFA more safely with respect to the hemoperitoneum caused by percutaneous radiofrequency ablation compared with platelet transfusion.

Radiofrequency ablation of hepatocellular carcinoma guided by real-time physics-based ablation simulation: a prospective study

Objectives To assess the safety and efficacy of radiofrequency ablation (RFA) guidance software that incorporated patient-specific physics-based simulation of each ablation volume. Materials and methods Patients referred for curative ablation of hepatocellular carcinoma (HCC) of 2–5 cm diameter were prospectively enrolled. RFA was performed under general anesthesia. Procedure planning and intraprocedural modifications were guided by computer simulation of each ablation. The segmented target (tumor with 5 mm margin) was registered to and superimposed on subsequent 3D multiplanar images. The applied RF energy was used to calculate a simulated ablation volume which was displayed relative to the electrode and segmented target, to depict any untreated target tissue. After each additional ablation, the software updated the accumulated simulated ablation volume in relation to the target. The primary endpoints were technical efficacy and rate of local tumor progression (LTP). Results Sixty-eight tumors were ablated during 57 procedures in 52 patients (68.3 ± 9.2 years old, 78.8% male); 15 (26.3%) had multiple lesions and 23 (39.1%) had prior HCC treatment. The mean tumor diameter was 2.73 (±0.64) cm. The intraprocedural simulation directed additional overlapping ablations in 75.9% of tumors. Technical success and efficacy were 100% at 3-month contrast enhanced CT or MRI follow-up after the single treatment session. Cumulative incidence function estimates for 1- and 2-year LTP were 3.9% and 20.2%, respectively. Conclusion This prospective study found computer-assisted guidance that simulated each ablation was both safe and efficacious. The low rate of LTP was similar to studies that employed stereotactic guidance and ablation confirmation, without requiring a second contrast enhanced study.

Radiofrequency hyperthermia enhances the effect of OK-432 for Hepatocellular carcinoma by activating of TLR4-cGAS-STING pathway

Radiofrequency ablation (RFA) has been used as an alternative to surgical management of early-stage hepatocellular carcinoma (HCC). However, when large and irregular HCCs are subjected to RFA, a safety margin is usually difficult to obtain, thus causing a sublethal radiofrequency hyperthermia (RFH) at the ablated tumor margin. This study investigated the feasibility of using RFH to enhance the effect of OK-432 on HCC, with the aim to generate a tumor-free margin during RFA of HCC. Our results showed OK-432 could activate the cGAS-STING pathway, and RFH could further enhance the activation. Meanwhile, RFH could induce a high expression of TLR4, and TLR4 might be an upstream molecular of the cGAS-STING pathway. The combined therapy of RFH with OK-432 resulted in a better tumor response, and a prolonged survival compared to the other three treatments. In conclusion, RFH in combination with OK-432 might reduce the residual and recurrent tumor after RFA of large and irregular HCCs, and serve as a new option for other solid malignancies treated by RFA.

Can Machine Learning Predict Favorable Outcome After Radiofrequency Ablation of Hepatocellular Carcinoma?

The standard practice for limited-stage hepatocellular carcinoma (HCC) is the resection or the use of local ablative techniques, such as radiofrequency ablation (RFA). The outcome after RFA depends on a complex interaction between the patient's general condition, hepatic function, and disease stage. In this study, we aimed to explore using a machine learning model to predict the response. A retrospective study was conducted for patients with RFA for a localized HCC between 2018 and 2022. The collected clinical, radiologic, and laboratory data were explored using Python and XGBoost. They were split into a training set (70%) and a validation set (30%). The primary end point of this study was to predict the probability of achieving favorable outcomes 12 months after RFA. Favorable outcomes were defined as the patient was alive and HCC was controlled. One hundred and eleven patients were eligible for the study. Males were 78 (70.3%) with a median age of 57 (range of 43-81) years. Favorable outcome was seen in 62 (55.9%) of the patients. The 1-year survival rate and control rate were 94.6%, and 61.3%, respectively. The final model harbored an accuracy and an AUC of 90.6% and 0.95, respectively, for the training set, while they were 78.9% and 0.80, respectively, for the validation set. Machine learning can be a predictive tool for the outcome after RFA in patients with HCC. Further validation by a larger study is necessary.

Incidence and clinical impact of bile ducts changes after multibipolar radiofrequency ablation for hepatocellular carcinoma

Incidence and clinical impact of bile ducts changes after multibipolar radiofrequency ablation for hepatocellular carcinoma

Combined Ultrasound and Computed Tomography Guidance in Radiofrequency Ablation for Hepatocellular Carcinoma Reduces Local Recurrence Rate

Background/Aim: In radiofrequency ablation (RFA) treatment of hepatocellular carcinoma (HCC), the therapeutic effect depends on the appropriate position of the electrode. To improve the accuracy of the electrode needle position, we currently perform RFA with combined ultrasound sonography (US) and computed tomography (CT) guidance. The purpose of this study was to evaluate the effectiveness of this US/CT-guided RFA method. Patients and Methods: This retrospective study recruited 97 patients with single tumors treated with transcatheter arterial chemoembolization and monopolar RFA between January 2013 and December 2017. Among these, 50 patients were treated with RFA under US/CT guidance (US/CT-guided group) and 47 were treated with RFA under US guidance alone (US-guided group). We analyzed the efficacy of US/CT guidance compared with US guidance alone. Results: The 1-, 2-, and 3-year local recurrence rates for the US/CT-guided and US-guided groups were 4.1%, 6.3%, and 8.6%, and 19.6%, 31.6%, and 41.9%, respectively. The local recurrence rate was lower in the US/CT-guided group (p=0.0030). Cox proportional hazards model for multivariate analysis demonstrated that the independent risk factors associated with local recurrence were tumor size (p=0.0028) and US/CT guidance (p=0.0037). Conclusion: US/CT-guided RFA for HCC reduced the local recurrence rate compared with US-guided RFA alone.

Combined Transarterial Chemoembolization and Radiofrequency Ablation for Hepatocellular Carcinoma Infeasible for Ultrasound-Guided Percutaneous Radiofrequency Ablation: A Comparative Study with General Ultrasound-Guided Radiofrequency Ablation Outcomes.

This study aimed to evaluate the therapeutic outcomes of transarterial chemoembolization combined with radiofrequency ablation (TACE + RFA) for hepatocellular carcinomas (HCC) measuring ≤3 cm infeasible for ultrasound (US)-guided percutaneous RFA. Twenty-four patients who underwent fluoroscopy-guided TACE + RFA for single HCC between January 2012 and December 2016 were screened. To evaluate the TACE + RFA outcomes compared with those of US-guided RFA, 371 patients who underwent US-guided RFA during the same period were screened. We compared local tumor progression (LTP) and intrahepatic distant recurrence (IDR) between the two groups before and after propensity score (PS) matching, and performed univariable and multivariable Cox proportional hazard regression analyses for all patients. PS matching yielded 21 and 42 patients in the TACE + RFA and US-guided RFA groups, respectively. Cumulative LTP rates after PS matching were not significantly different between the two groups at 1 (0.0% vs. 7.4%, p = 0.072), 2 (10.5% vs. 7.4%, p = 0.701), and 5 years (16.9% vs. 10.5%, p = 0.531). IDR rates did not differ significantly between the two groups at 1 (20.6% vs. 10%, p = 0.307), 2 (25.9% vs. 25.9%, p = 0.999), or 5 years (49.9% vs. 53%, p = 0.838). Multivariable analysis showed that treatment type was not a significant factor for LTP or IDR. The outcomes of TACE + RFA for HCC were similar to those of general US-guided RFA. Fluoroscopy-guided TACE + RFA may be an effective treatment when US-guided RFA is not feasible.

Thermal Injury to the Subhepatic Appendix Following Percutaneous Ultrasound-Guided Radiofrequency Ablation for Hepatocellular Carcinoma: A Case Report.

We present the first documented case of a fistula between the treated zone and the appendix after RFA in a patient with HCC. Contrast-enhanced CT and MRI revealed a subcapsular hepatic nodule with image findings of HCC located adjacent to the ascending colon and cecum. An ultrasound-guided core needle biopsy was subsequently performed to distinguish between hepatic metastasis and HCC. Post-RFA imaging identified a low-attenuating ablated area adjacent to an air-filled appendix. The patient later experienced complications, including increased liver enzymes and an abscess at the ablation site. Imaging revealed a fistulous tract between the RFA zone and the appendix. Over the following months, the patient underwent conservative treatment involving intravenous antibiotics and repeated percutaneous drainage, exhibiting eventual symptom relief and an absence of the fistulous tract upon subsequent imaging. This case highlights the rare complications that can arise during RFA due to peculiar anatomical variations, such as a subhepatic appendix, resulting from midgut malrotation and previous surgery. It is imperative for operators to be cognizant of potential anatomical variations when considering RFA treatment, ensuring comprehensive pre-procedural imaging and post-procedure monitoring. This case also emphasizes the potential viability of nonoperative management in complex scenarios in which surgical interventions pose significant risks.

Primary versus Salvage Liver Transplantation after Curative-Intent Resection or Radiofrequency Ablation for Hepatocellular Carcinoma: Long-Term Oncological Outcomes.

Liver transplantation for hepatocellular carcinoma (HCC) may be performed ab initio, primary liver transplantation (PLT), or for HCC recurrence after previous treatments such as liver resection (LR) or radiofrequency ablation (RFA), salvage liver transplantation (SLT). The aim of this study was to evaluate the oncological outcomes of SLT vs. PLT. For this, a retrospective study was carried out on patients undergoing liver transplantation for HCC. The outcomes of PLT were compared with those of SLT. The primary outcome was disease-free survival (DFS). The secondary outcomes included overall survival (OS), cancer-specific survival (CSS), and major postoperative complications. A sub-analysis of SLT-LR and SLT-RFA was also performed. In total, 141 patients were included: 96 underwent PLT and 45 SLT. Among the SLT group, 25 patients had undergone previous LR while 20 had had RFA. There were no differences in the major postoperative complications. Unadjusted DFS was significantly longer in the PLT group (p = 0.02), as were OS (p = 0.025) and CSS (p = 0.001). There was no difference in DFS between PLT and SLT-LR groups, while a significant difference was found between the PLT and SLT-RFA groups (p = 0.035). Nonetheless, DFS was no different between the SLT-LR and SLT-RFA groups. PLT appears to offer superior long-term oncological outcomes to SLT. Both SLT-LR and SLT-RFA offer acceptable OS and CSS. Further prospective studies are needed to confirm these results, but the re-direction of grafts and transplant philosophy towards PLT rather than SLT may need to be considered.

Long-term outcome and eligibility of radiofrequency ablation for hepatocellular carcinoma over 3.0 cm in diameter

Percutaneous radiofrequency ablation (RFA) is effective for the treatment of small hepatocellular carcinoma (HCC) with a diameter ≤ 3.0 cm. The present study aimed to elucidate the prognostic factors and clarify the indication of treatment for RFA outcomes in patients with HCC with a diameter > 3.0 cm. Among 2188 patients with HCC who underwent RFA, 100 patients with HCC with a diameter > 3.0 cm were enrolled in this study between August, 2000 and August, 2021. We analyzed local therapeutic efficacy, long-term outcomes, and prognostic factors in patients with HCC with a diameter > 3.0 cm. Among all patients, 77 patients achieved complete ablation in one session. There were no treatment-related deaths or major complications. Local tumor recurrence occurred in 48% (n = 48) of the patients, and distant tumor recurrence occurred in 82% (n = 82) of the patients during the study period. The survival rates at 1-, 3-, 5-, 10-, and 15- years were 93.0%, 66.0%, 40.0%, 15.5%, and 10.2%, respectively. Cox proportional hazards regression analysis confirmed that distant tumor recurrence, Child–Pugh class B, and pre-ablation des-γ-carboxy prothrombin (DCP) levels ≥ 200 mAU/mL were independent unfavorable prognostic factors with a hazard ratio of 3.34 (95% CI, 1.57–7.11; P = 0.002), 2.43 (95% CI, 1.35–4.37; P = 0.003), and 1.83 (95% CI, 1.14–2.93; P = 0.012), respectively. In conclusion, patients with HCC with a diameter > 3.0 cm with Child–Pugh class A and DCP levels < 200 mAU/mL might be eligible for RFA treatment.

An evaluation of 20-year survival of radiofrequency ablation for hepatocellular carcinoma as first-line treatment

ObjectivesTo evaluate the changes in clinical characteristics, overall survival (OS), and progression-free survival (PFS) by investigating a 20-year cohort of patients with HCC who underwent RFA treatment. MethodsFrom 2000 to 2020, 505 consecutive patients with HCC underwent ultrasound-guided percutaneous RFA as first-line therapy at a tertiary cancer hospital. We divided the cohort according to the time when hepatitis-B antiviral therapy was covered by national medical insurance coverage (early 2011), including the first decade (2000–2010) and second decade (2011–2020). The prognostic factors for OS were analyzed by the Cox proportional hazard model. OS and PFS in different groups were compared using the Kaplan-Meier method. To reduce selection bias, matched groups of patients were selected using the propensity score matching (PSM) method. ResultsIn total, 726 RFA sessions were performed to treat 867 HCC lesions. Patients treated in the second decade were younger (p =.047), had smaller tumors (p <.001), had lower Child-Pugh scores (p <.001), and had a higher proportion of antiviral treatment (p <.001). A total of 96.0% of patients achieved technical efficacy from the initial RFA. After PSM analysis, improved PFS was found for the second decade (median, 68 vs. 49 months, p =.003), but no significant difference in OS was observed between the two groups (median, 71 vs. 65 months, p =.20). ConclusionsThis study demonstrated that improved PFS was achieved in patients with HCC receiving RFA as first-line treatment in the second decade. However, long-term OS was not significantly increased compared to the first decade suggesting that while RFA treatment has improved, it still might not substantially affect OS results.

Contrast-enhanced harmonic EUS-guided radiofrequency ablation of hepatocellular carcinoma: a new horizon in endohepatology.

Video 1Contrast-enhanced harmonic EUS-guided radiofrequency ablation of hepatocellular carcinoma.

Synergistic effect of OK-432 in combination with an anti-PD-1 antibody for residual tumors after radiofrequency ablation of hepatocellular carcinoma

Background and aimsRadiofrequency ablation (RFA) often results in incomplete ablation for medium-to-large and irregular tumors. To solve this clinical problem, we proposed a new treatment strategy of OK-432 in combination with an anti-programmed cell death protein 1 (αPD-1) antibody for residual tumors after incomplete RFA (iRFA) of hepatocellular carcinoma (HCC). Approach and resultsThe effect of OK-432 on immature dendritic cells (iDCs) was evaluated in vitro. A CCK-8 kit and ELISPOT were used to assess the killing effect of OK-432-induced CD8+ T cells in combination with an αPD-1 antibody on Hepa1–6 cells. We found that OK-432 significantly increased the maturation level of DCs, and OK-432-induced CD8+ T cells in combination with αPD-1 antibody significantly enhanced the function of CD8+ T cells. In the in vivo experiment, HCC model mice were treated with (1) pseudo iRFA + phosphate-buffered saline (PBS); (2) iRFA + PBS; (3) iRFA + OK-432; (4) iRFA + αPD-1; or (5) iRFA + OK-432 + αPD-1. We found that the combined therapy of OK-432 with αPD-1 antibody significantly increased the infiltration and function of CD8+ T cells and significantly decreased the number of FoxP3+ regulatory T cells in residual tumors after iRFA of HCC. Moreover, the smallest tumor volumes and the longest survival were observed in the triple combination treatment (iRFA+OK-432 +αPD-1 antibody) group compared with the other four groups. ConclusionsThe combined therapy of OK-432 with αPD-1 antibody induced a strong antitumor immune response, which significantly inhibited the residual tumors after iRFA of HCC. This concept may provide a new treatment strategy to increase the curative efficacy of RFA for medium-to-large and irregular HCCs. Availability of data and materialThe data of this study are available from the corresponding author on reasonable request.

3D fusion is superior to 2D point-to-point contrast-enhanced US to evaluate the ablative margin after RFA for hepatocellular carcinoma.

To compare the efficiency of three-dimensional (3D) and two-dimensional (2D) contrast-enhanced ultrasound (CEUS)-derived techniques in evaluating the ablative margin (AM) after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). In total, 98 patients with 98 HCCs were enrolled. The 2D CEUS point-to-point imaging (2D CEUS-PI) was conducted by comparing the pre- and post-RFA 2D CEUS images manually, and the 3D CEUS fusion imaging (3D CEUS-FI) was conducted by fusing the pre- and post-RFA 3D CEUS images automatically. These two techniques were compared in distinguishing an adequate AM ≥ 5mm. Risk factors for local tumor progression (LTP) after RFA were analyzed by the Kaplan-Meier method with log-rank test. The mean registration time of 3D CEUS-FI and 2D CEUS-PI was 5.0 and 9.3min, respectively (p < 0.0001). The kappa coefficient was 0.680 for agreement between 2D CEUS-PI and 3D CEUS-FI in the evaluation of AM (p < 0.0001). Tumors with AM < 5mm by 2D CEUS-PI were all identified as AM < 5mm by 3D CEUS-FI. Nonetheless, 16 (26%) tumors identified as AM ≥ 5mm by 2D CEUS-PI were re-classified as AM < 5mm by 3D CEUS-FI. During a median follow-up time of 31.2months (range, 3.2-66.0months), LTP was identified in 8 tumors. The estimated 1-/2-/3-year cumulative incidence of LTP was 4.4%, 8.1%, and 10.3%, respectively. Higher estimated cumulative incidence of LTP was identified in tumors with AM < 5mm by 2D CEUS-PI (at 3-year, 27.2% vs 0%; p < 0.001), and by 3D CEUS-FI (at 3-year, 20.7% vs 0%; p = 0.004). 3D CEUS-FI excelled in the evaluation of AM when compared with 2D CEUS-PI. With equivalent efficacy in the prediction of LTP, 3D CEUS-FI was superior to 2D CEUS-PI for its automatic and time-saving procedure. 3D CEUS fusion imaging may serve as an effective tool in evaluating ablative margin and predicting local tumor progression after RFA in HCC. • Both 2D and 3D CEUS-derived techniques could evaluate ablative margin (AM) after RFA for hepatocellular carcinoma. • 3D CEUS fusion imaging was more precise in the evaluation of AM compared to 2D CEUS point-to-point imaging, with advantages of its automatic and time-saving procedure. • An inadequate AM < 5mm evaluated by CEUS-derived techniques was the only risk factor of LTP after RFA for hepatocellular carcinoma (p < 0.001 for 2D CEUS point-to-point imaging, and p = 0.004 for 3D CEUS fusion imaging).

Retracted: Application and Evaluation of a 64-Slice CT Three-Dimensional Fusion Technique in the Determination of the Effective Ablation Margin after Radiofrequency Ablation of Hepatocellular Carcinoma.

[This retracts the article DOI: 10.1155/2022/6898233.].

Factors associated with increased risk of peritoneal seeding after radiofrequency ablation for hepatocellular carcinoma.

To evaluate the incidence, risk factors, and prognosis associated with peritoneal seeding after percutaneous radiofrequency ablation (RFA) for HCC, focusing on viable tumors after previous locoregional treatment, including TACE and RFA. Exactly 290 patients (mean age, 67.9years ± 9.74; 223 men) with 383 HCCs (mean size, 15.9mm ± 5.49) who underwent RFA between June 2012 and December 2019 were included in this retrospective study. Among them, 158 had history of previous treatment (mean number, 1.3 ± 1.8) with 109 viable HCCs. Cumulative seeding after RFA was estimated using the Kaplan-Meier method. Independent factors affecting seeding were investigated using multivariable Cox proportional hazards regression analysis. Median follow-up was 1175days (range: 28-4116). Seeding incidence was 4.1 (12/290) and 4.7% (17/383) per patient and tumor, respectively. The median time interval between RFA and detection of seeding was 785days (range: 81-1961). Independent risk factors for seeding included subcapsular tumor location (hazard ratio [HR] 4.2; 95% confidence interval [CI] 1.4, 13.0; p = 0.012) and RFA for viable HCC after previous locoregional treatment (HR 4.5; 95% CI 1.7, 12.3; p = 0.003). Subgroup analysis for viable tumors, revealed no significant difference in cumulative seeding rates between the TACE and RFA groups (p = 0.078). Cumulative overall survival rates differed significantly between patients with and without seeding metastases (p < 0.001). Peritoneal seeding after RFA is a rare, delayed complication. Subcapsular-located and viable HCC after previous locoregional treatment are potential risk factors for seeding. Seeding metastases could affect the prognosis of patients who cannot receive local therapy.

THU-118 - Application of deep learning auto-segmentation and unsupervised machine learning in developing a radiomic prognostic score to predict disease recurrence post radiofrequency ablation for hepatocellular carcinoma

THU-118 - Application of deep learning auto-segmentation and unsupervised machine learning in developing a radiomic prognostic score to predict disease recurrence post radiofrequency ablation for hepatocellular carcinoma

Predictive Factors of Treatment Outcomes After Percutaneous Radiofrequency Ablation of Hepatocellular Carcinoma in the Hepatocaval Confluence: A Propensity Score Matching Analysis

To compare the efficacy and complications ofultrasound-guided percutaneous radiofrequency ablation of hepatocellular carcinoma (HCC) in the hepatocaval confluence with those of HCC in the non-hepatocaval confluence and to explore the risk factors that lead to radiofrequency ablation failure and patient local tumor progression (LTP). From January 2017 to January 2022, 86 patients with HCC in the hepatocaval confluence who had radiofrequency ablation were included. A 1:1 propensity-matched group of patients with HCC in the non-hepatocaval confluence with comparable clinical baseline traits, such as tumor diameter and tumor number, served as the control group. The two groups' complications, primary efficacy rate (PER), technical success rate (TSR), and prognosis were estimated. After PSM, no significant difference of TSR (91.7% vs 95.8%, p=0.491) and PER (95.8% vs 97.2%, p=1.000) and 1-, 3-, and 5-year LTP rate (12.5% vs 9.9%, 28.2% vs 27.7%, 40.8% vs 43.8%, p=0.959) and 1-, 3-, and 5-year DFS rate (87.5% vs 87.5%, 62.3% vs 54.2%, 18.1% vs 22.6%, p=0.437) and 1-, 3-, and 5-year OS rate (94.3% vs 95.7%, 72.7% vs 69.6%, 20.9% vs 33.6%, p=0.904) was detected between the two groups. The tumor-to-IVC distance was an independent risk factor for radiofrequency ablation failure in HCC patients in the hepatocaval confluence (OR=0.611, p=0.022). Besides, tumor diameter was an independent risk factor for predicting LTP in patients with HCC in the hepatocaval confluence (HR=2.209, p=0.046). HCC in the hepatocaval confluence can be effectively treated with radiofrequency ablation. To maximize treatment efficacy, the tumor-to-IVC distance and tumor diameter should be assessed before the operation begins.

Unexpected Bronchomalacia Combined with Excessive Dynamic Airway Collapse was Diagnosed by Intraoperative Bronchoscopy: A Case Report

Expiratory central airway collapse (ECAC) comprises tracheobronchomalacia (TBM) and excessive dynamic airway collapse (EDAC). ECAC is a progressive disease that can be congenital or acquired, and it can be confirmed by inspiratory-dynamic expiratory chest CT or dynamic bronchoscopy. We present the case of a 65-year-old man who underwent radiofrequency ablation for hepatocellular carcinoma under general anesthesia. After tracheal intubation in the operating room, the respiratory sound in the left lung disappeared, and the respiratory sound in the right lung was clear during chest auscultation. Bronchoscopy revealed complete collapse of the left main bronchus. Intraoperative bronchoscopy confirmed that the patient had ECAC (both TBM and EDAC).

Simulating radiofrequency ablation of hepatocellular carcinomas proximal to bare area of liver

Purpose To numerically assess the significance of dextrose 5% in water (D5W) thermo-protection during radiofrequency ablation (RFA) of hepatocellular carcinomas (HCCs) located near the ‘bare area of liver’. Material and methods This study utilises quasi-anatomical structures extracted from CT images. A multi-tine electrode, deployed inside the extracted organs and operated under temperature-controlled mode was used as the source of ablation. Geometrically, D5W was modelled around the ‘bare area’ and sandwiched between the liver and diaphragm. RFA at different sites relative to the ‘bare area’ was simulated to answer when to consider modelling D5W. Results For targets near the edge of ‘bare area’ and at 0.5 mm gap (between the electrode and the ‘bare area’), ignoring D5W and using ground conditions could result in underestimation of ablation volume by almost 25%. The importance of D5W becomes negligible for ablations near the centre of the ‘bare area’. Conclusions Consideration of D5W during RFA of HCCs proximal to the ‘bare area’ can significantly influence the ablation outcome, especially when ablation is performed near the edge of the ‘bare area’.