Quality initiatives: strategies for anticipating and reducing complications and treatment failures in hepatic radiofrequency ablation

Radiofrequency ablation for peribiliary hepatocellular carcinoma: propensity score matching analysis

OBJECTIVES

At present, there are no established clinical guidelines for radiofrequency ablation (RFA) of peribiliary hepatocellular carcinoma (HCC). Therefore, the aim of this study was to compare the long-term outcomes of RFA for peribiliary vs. non-peribiliary HCC.

METHODS

This retrospective study included 282 patients with peribiliary HCC (n = 109) or non-peribiliary HCC (n = 173) who received RFA between February 2013 and May 2021. Local tumor progression (LTP), overall survival (OS), disease-free survival (DFS), and complications were compared before and after propensity score matching (PSM).

RESULTS

Before PSM, there were no significant differences in 5-year LTP rates (26.3% vs. 23.6%, p = 0.602), OS rates (56.6% vs. 68.0%, p = 0.586), or DFS rates (22.9% vs. 25.7%, p = 0.239) between the peribiliary and non-peribiliary groups. After PSM, there were no significant differences in the 1-, 3-, and 5-year LTP rates (13.0%, 23.1%, and 26.3% vs. 12.1%, 25.1%, and 28.2%, respectively, p = 0.857), OS rates (97.2%, 73.5%, and 56.6% vs. 95.3%, 79.5%, and 70.6%, p = 0.727), or DFS rates (59.4%, 29.4%, and 22.9% vs. 64.2%, 33.1%, and 23.8%, p = 0.568) between the peribiliary non-peribiliary groups. Peribiliary location was not a significant prognostic factor for LTP (p = 0.622) or OS (p = 0.587). In addition, mild intrahepatic bile duct dilatation was more frequent in the peribiliary group (9.2% vs. 2.8%, p = 0.045).

CONCLUSION

Long-term outcomes of RFA were similar for peribiliary and non-peribiliary HCC. RFA is a viable alternative for treatment of peribiliary HCC.

CRITICAL RELEVANCE STATEMENT

The local tumor progression (LTP), overall survival (OS), and disease-free survival (DFS) rates after radiofrequency ablation (RFA) were similar for peribiliary and non-peribiliary hepatocellular carcinoma (HCC).

KEY POINTS

There are currently no clinical guidelines for radiofrequency ablation (RFA) of peribiliary hepatocellular carcinoma (HCC). Local tumor progression, overall survival, and disease-free survival after RFA were similar for peribiliary and non-peribiliary HCC. RFA is a viable alternative for the treatment of peribiliary HCC.

Complications of Percutaneous Radiofrequency Ablation for Hepatocellular Carcinoma

Radiofrequency ablation (RFA) is a potentially curative treatment option for early Hepatocellular carcinoma. The RFA is considered safe with a relatively low incidence of complications ranging from 2%-7.9%. Though most of the complications are self-limiting, sometimes they can be life-threatening. The occurrence of the particular complication depends on various factors like tumour location and morphology, underlying disease and ablation technique. A detailed understanding of potential complications along with the associated risk factors will help to employ strategies to prevent them, identify them early and manage them when they occur. This article demonstrates various radiofrequency ablation-related complications and discusses the risk factors and technical strategies to minimise them and achieve complete ablation of the tumour.

Design of Path-Planning System for Interventional Thermal Ablation of Liver Tumors Based on CT Images

OBJECTIVE

Aiming at the shortcomings of artificial surgical path planning for the thermal ablation of liver tumors, such as the time-consuming and labor-consuming process, and relying heavily on doctors' puncture experience, an automatic path-planning system for thermal ablation of liver tumors based on CT images is designed and implemented.

METHODS

The system mainly includes three modules: image segmentation and three-dimensional reconstruction, automatic surgical path planning, and image information management. Through organ segmentation and three- dimensional reconstruction based on CT images, the personalized abdominal spatial anatomical structure of patients is obtained, which is convenient for surgical path planning. The weighted summation method based on clinical constraints and the concept of Pareto optimality are used to solve the multi-objective optimization problem, screen the optimal needle entry path, and realize the automatic planning of the thermal ablation path. The image information database was established to store the information related to the surgical path.

RESULTS

In the discussion with clinicians, more than 78% of the paths generated by the planning system were considered to be effective, and the efficiency of system path planning is higher than doctors' planning efficiency.

CONCLUSION

After improvement, the system can be used for the planning of the thermal ablation path of a liver tumor and has certain clinical application value.

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'.

Efficacy and safety of computed tomography-guided microwave ablation with fine needle-assisted puncture positioning technique for hepatocellular carcinoma

BACKGROUND

In microwave ablation (MWA), although computed tomography (CT) scanning can overcome gas interference, it cannot achieve real-time localization. Therefore, the puncture technique is more important in CT-guided ablation.

AIM

To compare the fine needle-assisted puncture (FNP) positioning technique and the conventional puncture (CP) technique for the safety and efficacy of CT-guided MWA in treating hepatocellular carcinoma (HCC).

METHODS

This retrospective study included 124 patients with 166 tumor nodules from February 2018 and June 2021. Seventy patients received CT-guided MWA under the FNP technique (FNP group), and 54 patients received MWA under the CP technique (CP group). Intergroup comparisons were made regarding local tumor progression (LTP), recurrence-free survival (RFS), overall survival (OS), and complications. The influencing variables of LTP and RFS were analyzed through univariate and multivariate regressions.

RESULTS

The 1-, 2-, and 3-year cumulative incidences of LTP in the FNP group were significantly lower than those in the CP group (7.4%, 12.7%, 21.3% vs 13.7%, 32.9%, 36.4%; P = 0.038). The 1-, 2-, and 3-year RFS rates in the FNP group were significantly higher than those in the CP group (80.6%, 73.3%, 64.0% vs 83.3%, 39.4%, and 32.5%, respectively; P = 0.008). The FNP technique independently predicted LTP and RFS. Minor complications in the FNP group were lower than those in the CP group (P < 0.001). The difference in median OS was insignificant between the FNP and CP groups (P = 0.229).

CONCLUSION

The FNP technique used in CT-guided MWA may improve outcomes in terms of LTP, RFS, and procedure-related complications for HCC.

Evaluation of Hepatocellular Carcinoma Treatment Response After Locoregional Therapy

Locoregional therapy (LRT) for hepatocellular carcinoma can be used alone or with other treatment modalities to reduce rates of progression, improve survival, or act as a bridge to cure. As the use of LRT expands, so too has the need for systems to evaluate treatment response, such as the World Health Organization and modified Response Evaluation Criteria In Solid Tumors systems and more recently, the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA). Early validation results for LI-RADS TRA have been promising, and as research accrues, the TRA is expected to evolve in the near future.

Laparoscopic repair of diaphragmatic hernia after radiofrequency ablation for hepatocellular carcinoma: Case report

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Diaphragmatic hernia is a rare late-onset complication associated with RFA for HCC.

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The tumor location is closely related to the risk of diaphragmatic hernia caused by RFA.

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Patients with HCC often have severe liver dysfunction and cirrhosis.

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Laparoscopic approach is safe and minimally invasive for severe cirrhosis patient.

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The hernia gate was closed by suture, and vulnerable area was reinforced using mesh.

Introduction and importance

We describe the case of a patients with a diaphragmatic hernia associated with radiofrequency ablation for hepatocellular carcinoma who was treated by laparoscopic repair.

Case presentation

An 82-years-old man with history of HCC with hepatitis C virus-related liver cirrhosis (Child-Pugh B). The patient was treated RFA to HCC for segment 4, 5, 6, 8.

After 16 months from latest RFA for segment 8, the patient was admitted to our hospital because of mild dyspnea. Computed tomography revealed a diaphragmatic herniation of bowel loops into the right thoracic cavity. The patients electively underwent laparoscopic repair of the diaphragmatic hernia. The patient was discharged from hospital without any post-operative complications.

Clinical discussion

The only treatment to diaphragmatic hernia is surgery, but liver cirrhosis patients limits this possibility. For the surgical treatment of patients with severe cirrhosis, the operation should be carefully assessed. We believe that a laparoscopic approach should be used for repairing diaphragmatic hernia. In the present case, we considered that a laparoscopic approach was safer and more feasible than open laparotomy.

Conclusion

Diaphragmatic hernia is a rare late-onset complication associated with RFA for HCC. And patients with HCC often have severe liver dysfunction and cirrhosis. A laparoscopic approach is safe and minimally invasive for sever cirrhosis patients.

Directional ablation in radiofrequency ablation using a multi-tine electrode functioning in multipolar mode: An in-silico study using a finite set of states

PURPOSE

To analyse the feasibility of directional ablation using a multi-tine electrode.

METHODS

A multi-tine electrode capable of operating in multipolar mode has been used to study the directional ablation. In addition to the basic design, similar to commercially available FDA approved multi-tine electrode, tines have been insulated from each other inside the probe base and tip using a thin insulating material of thickness 0.25 mm. A cylindrical single-compartment model of size 6 cm × 6 cm has been used to model normal liver tissue. The temperature-controlled radiofrequency ablation has been employed to maintain the tine-tips at different temperatures. Electro-thermal simulations have been performed by using a commercial multi-physics software package based on finite element methods. To make this study feasible a new approach to predict the ablations have been proposed and used in this study.

RESULTS

Asymmetric ablation zone with up to 5 mm difference in ablation boundary between the intended and non-intended direction has been observed along the transverse direction. Reduction in ablation up to 5 mm along the axial direction in comparison to the monopolar mode has also been observed.

CONCLUSION

Multi-tine electrode modified to operate in multipolar mode can create directional ablations of different shapes and can be used to target position and shape specific tumours.

Automatic Radiofrequency Ablation Planning for Liver Tumors With Multiple Constraints Based on Set Covering

Radiofrequency ablation (RFA) is now a widely used minimally invasive treatment method for hepatic tumors. Preoperative planning plays a vital role in RFA therapy. With increasing tumor size, multiple overlapping ablations are needed, which are challenging to optimize while considering clinical constraints. In this paper, we present a new automatic RFA planning method. First, a 2-steps set cover-based model is formulated, which can integrate multiple clinical constraints for optimization of overlapping ablations. To ensure that the planning model can be solved in a reasonable time, a search space reducing strategy is then proposed. We also developed an algorithm for automatic RFA electrode selection, which provides a proper electrode ablation zone for the planning model. The proposed method was evaluated with 20 tumors of varying sizes (0.92 cm³ to 28.4 cm³). Results showed that the proposed method can generate clinical feasible RFA plans with a minimum number of RFA electrodes and ablations, complete tumor coverage and minimized ablation of normal tissue.

Novel Simulation Device for Targeting Tumors in Laparoscopic Ablation: A Learning Curve Study

Introduction. A novel 3-dimensional (3D) guidance system was developed to aid accurate needle placement during ablation. Methods. Five novices and 5 experienced hepatobiliary surgeons were recruited. Using an agar block with analog tumor, participants targeted under 4 conditions: in-line with the ultrasound plane using ultrasound, in-line using 3D guidance, 45° off-axis using ultrasound, and off-axis using 3D guidance. Time to target the tumor, number of withdrawals, and the National Aeronautics and Space Administration Task Load Index were collected. Initial and final parameters for each of the conditions were compared using a within-subjects paired t test. Results. A significant reduction was seen in the number of required withdrawals in all situations when using the 3D guidance (0.75 vs 3.65 in-line and 0.25 vs 3.6 for off-axis). Mental workload was significantly lower when using 3D guidance compared with ultrasound both for novices (29.85 vs 41.03) and experts (31.98 vs 44.57), P < .001 for both. The only difference in targeting time between first and last attempt was in the novice group during off-axis targeting using 3D guidance (115 vs 32.6 seconds, P = .03). Conclusion. Though 3D guidance appeared to decrease time to target, this was not statistically significant likely as a result of lack of power in our trial. Three-dimensional guidance did reduce the number of required withdrawals, potentially decreasing complications, as well as mental workload after proficiency was achieved. Furthermore, novices without experience in ultrasound were able to learn targeting with the 3D guidance system at a faster pace than targeting with ultrasound alone.

Ultrasound-Guided Percutaneous Radiofrequency Ablation of Liver Tumors: How We Do It Safely and Completely

Ultrasound-guided percutaneous radiofrequency (RF) ablation has become one of the most promising local cancer therapies for both resectable and nonresectable hepatic tumors. Although RF ablation is a safe and effective technique for the treatment of liver tumors, the outcome of treatment can be closely related to the location and shape of the tumors. There may be difficulties with RF ablation of tumors that are adjacent to large vessels or extrahepatic heat-vulnerable organs and tumors in the caudate lobe, possibly resulting in major complications or treatment failure. Thus, a number of strategies have been developed to overcome these challenges, which include artificial ascites, needle track ablation, fusion imaging guidance, parallel targeting, bypass targeting, etc. Operators need to use the right strategy in the right situation to avoid the possibility of complications and incomplete thermal tissue destruction; with the right strategy, RF ablation can be performed successfully, even for hepatic tumors in high-risk locations. This article offers technical strategies that can be used to effectively perform RF ablation as well as to minimize possible complications related to the procedure with representative cases and schematic illustrations.

Laparoscopic repair of a diaphragmatic hernia associated with radiofrequency ablation for hepatocellular carcinoma: lessons from a case and the review of the literature

We describe the case of a patient with a diaphragmatic hernia associated with radiofrequency ablation for hepatocellular carcinoma who was successfully treated by laparoscopic surgery. A 62-year-old man with a long history of hepatitis C-induced liver cirrhosis was admitted to our institution because of recurrent postprandial periumbilical pain. Eight years earlier, he had undergone radiofrequency ablation for hepatocellular carcinoma at hepatic segment VIII. Computed tomography, gastrografin enema examination revealed transverse colon obstruction because of a diaphragmatic hernia. We diagnosed diaphragmatic hernia associated with the prior radiofrequency ablation treatment. The patient underwent laparoscopic repair of the diaphragmatic hernia. Though the patient experienced the recurrence once, relaparoscopic treatment has improved the patient's conditions. Thus, diaphragmatic hernia can develop as a complication of radiofrequency ablation treatment. A laparoscopic approach is safe, feasible, and minimally invasive, even in patients with cirrhosis who develop iatrogenic diaphragmatic hernia as a complication of radiofrequency ablation treatment.

MAFR. Complications of radiofrequency ablation of hepatic tumors: Frequency and risk factors

Radiofrequency ablation (RFA) has become an important option in the therapy of primary and secondary hepatic tumors. Surgical resection is still the best treatment option, but only a few of these patients are candidates for surgery: multilobar disease, insufficient liver reserve that will lead to liver failure after resection, extra-hepatic disease, proximity to major bile ducts and vessels, and co-morbidities. RFA has a low mortality and morbidity rate and is considered to be safe. Thus, complications occur and vary widely in the literature. Complications are caused by thermal damage, direct needle injury, infection and the patient’s co-morbidities. Tumor type, type of approach, number of lesions, tumor localization, underlying hepatic disease, the physician’s experience, associated hepatic resection and lesion size have been described as factors significantly associated with complications. The physician in charge should promptly recognize high-risk patients more susceptible to complications, perform a close post procedure follow-up and manage them early and adequately if they occur. We aim to describe complications from RFA of hepatic tumors and their risk factors, as well as a few techniques to avoid them. This way, others can decrease their morbidity rates with better outcomes.

Bile aspiration and hydrodissection to prevent complications in hepatic RFA close to the gallbladder

BACKGROUND

Radiofrequency ablation (RFA) of liver tumors is a mainstay of interventional oncology. Its application, however, is limited by tumor size and location with lesions located within 1 cm to the gallbladder being at increased risk for complications.

PURPOSE

To evaluate the safety of hepatic RFA after bile aspiration with or without additional hydrodissection for lesions adjacent to the gallbladder.

MATERIAL AND METHODS

Six patients undergoing RFA of tumors with a distance of less than 1 cm to the gallbladder were retrospectively identified from a computer database. All patients underwent RFA combined with percutaneous bile aspiration from the gallbladder. In four patients additional hydrodissection was performed. Technical success and post-interventional complications were assessed by reviewing images and patient charts.

RESULTS

Ablations were successfully completed in 5/6 patients. In one patient with incomplete ablation re-ablation was performed 2 months after the initial procedure. Minor complications occurred in three patients, including right-sided pleural effusion, hematoma in the gallbladder fossa, and intralesional hemorrhage in one patient each. There were no cases with cholecystitis or damage to the gallbladder during follow-up.

CONCLUSION

Bile aspiration with or without additional hydrodissection permits safe RFA of tumors located close to the gallbladder.

Laparoscopic repair of iatrogenic diaphragmatic hernia following radiofrequency ablation for hepatocellular carcinoma

Radiofrequency ablation (RFA) is commonly used for treating unresectable hepatic malignancies. Some commonly associated complications of RFA include fever, symptomatic pleural effusion, abscess, hepatoma and hepatic insufficiency. Here, we report a case of diaphragmatic hernia in a patient following RFA for hepatic malignancy with cirrhosis.

Comparison between different thickness umbrella-shaped expandable radiofrequency electrodes (SuperSlim and CoAccess): Experimental and clinical study

The purpose of the present study was to compare the size and configuration of the ablation zones created by SuperSlim and CoAccess electrodes, using various ablation algorithms in ex vivo bovine liver and in clinical cases. In the experimental study, we ablated explanted bovine liver using 2 types of electrodes and 4 ablation algorithms (combinations of incremental power supply, stepwise expansion and additional low-power ablation) and evaluated the ablation area and time. In the clinical study, we compared the ablation volume and the shape of the ablation zone between both electrodes in 23 hepatocellular carcinoma (HCC) cases with the best algorithm (incremental power supply, stepwise expansion and additional low-power ablation) as derived from the experimental study. In the experimental study, the ablation area and time by the CoAccess electrode were significantly greater compared to those by the SuperSlim electrode for the single-step (algorithm 1, p=0.0209 and 0.0325, respectively) and stepwise expansion algorithms (algorithm 2, p=0.0002 and <0.0001, respectively; algorithm 3, p= 0.006 and 0.0407, respectively). However, differences were not significant for the additional low-power ablation algorithm. In the clinical study, the ablation volume and time in the CoAccess group were significantly larger and longer, respectively, compared to those in the SuperSlim group (p=0.0242 and 0.009, respectively). Round ablation zones were acquired in 91.7% of the CoAccess group, while irregular ablation zones were obtained in 45.5% of the SuperSlim group (p=0.0428). In conclusion, the CoAccess electrode achieves larger and more uniform ablation zones compared with the SuperSlim electrode, though it requires longer ablation times in experimental and clinical studies.