Imaging guided percutaneous interventions in hepatic dome lesions: Tips and tricks

Percutaneous Robotics in Interventional Radiology

The accuracy of the robotic device not only relies on a reproducible needle advancement, but also on the possibility to correct target movement at chosen checkpoints and to deviate from a linear to a nonlinear trajectory. We report our experience in using the robotic device for the insertion of trocar needles in CT guided procedures. The majority of procedures were targeted organ biopsies in the chest abdomen or pelvis. The accuracy of needle placement after target adjustments did not significantly differ from those patients where a linear trajectory could be used. The steering capabilities of the robot allow correction of target movement of the fly.

Diaphragmatic Injury with Empyema Development after Microwave Ablation of a Liver Dome Lesion

Percutaneous microwave ablation (MWA) of the liver is a minimally invasive procedure that utilizes high frequency electromagnetic waves to generate heat and induce tumor necrosis. MWA has been proven to be a safe and effective treatment option for primary and metastatic liver tumors. The treatment of liver dome lesions can present a technical challenge due to the proximity of the hepatic dome to the diaphragm and lung parenchyma. In this report, we present a case of diaphragmatic injury and subsequent empyema following MWA of a liver dome lesion.

CT-guided microwave ablation of hepatic malignancies via transpulmonary approach without ancillary techniques

Objectives:

The objectives of the study were to determine the safety and efficacy of computed tomography (CT)-guided transpulmonary percutaneous microwave ablation (MWA) for hepatic malignancies without the use of ancillary techniques.

Material and Methods:

A retrospective review was performed on patients who underwent MWA for hepatic malignancy between January 2014 and February 2020 at a single tertiary center. Imaging was reviewed for each procedure to identify MWA showing transpleural transgression on CT scans. For these patients, demographics, ablation data, pulmonary complication rate, and predictors of pneumothorax were analyzed.

Results:

A total of 71 consecutive sessions (62.1 ± 11.3 years, 79% of males) of MWA were performed to treat 71 tumors (1.90 ± 0.96 cm) via transpulmonary approach under CT guidance. Technical success was achieved in all cases immediately after the procedure. At 1-month follow-up, 65/69 (94.2%) patients had no residual disease (two patients were lost to follow-up). Pulmonary complications occurred in 26/71 (36.6%) sessions, and 15/26 (57.7%) were minor requiring no intervention. Pneumothorax occurred in 14/71 (19.7%) sessions, and the rate of major pneumothorax requiring chest tube was 8/71 (11.3%). Lesions on the left side of the liver (segments I–IV) and intraprocedural probe adjustment were found to be independent predictors of developing major pneumothorax (P = 0.007 and 0.028, respectively). There were no reported pulmonary complications at the 1-month follow-up.

Conclusion:

CT-guided transpulmonary MWA is safe and effective in treating hepatic malignancies. Although it is associated with the risk of developing pulmonary complications, patients underwent successful ablation of their hepatic malignancies without life-threatening complications and mortality.

Percutaneous Radiofrequency Ablation (RFA) in renal cancer. How to manage challenging masses. A narrative review

In the last decades, the refinements in the imaging techniques led to an increased number of detected renal tumors. If radical and partial nephrectomy remain the gold standard for the treatment of renal cancer, Radio-Frequency Ablation (RFA) has emerged as a therapeutic option for renal masses. Even if this technique is minimally-invasive, it requires a proper preoperative anatomic study and in some cases RFA treatment is technically challenging. To date, there is no standardization for studying challenging cases before treatment and to plan a safe and effective procedure when intervening organs are in the trajectory of the needle. In this study we searched the literature focusing on the challenging cases and strategy applied to manage the treatment safely and effectively.

MATERIALS AND METHODS

MedLine and Embase via Ovid database were searched, using the following key words: Percutaneous RFA, radiofrequency, renal ablation, kidney ablation, renal thermoablation, kidney thermoablation, hydrodissection, heat sink. The difficulties found in the literature while performing the ablation procedure were grouped and a categorization of the strategies applied to perform a safe and effective procedure was proposed, in the aim to standardize the approach for treatment of challenging cases. Literature was analyzed according with selection criteria agreed by the Authors.

RESULTS

The literature review showed four groups of lesions requiring an experienced approach. Group 1: Lesions close to the bowel. Group 2: Lesions close to the urinary tract. Group 3: Lesions close to intervening organs. Group 4: Lesions close to large vessels (heat-sink phenomenon).

CONCLUSION

When planning a RFA treatment, a standardized approach to challenging masses is possible. This review make the treatment of these masses more systematic and safe.

Percutaneous microwave ablation of hepatic lesions near the heart

BACKGROUND

Early stage liver cancer is often treated with hepatic resection or transplantation for curative intent. Microwave ablation (MWA) is often performed in patients who are poor surgical candidates, patients with limited multifocal disease, disease close to hepatic vasculature, but can also be performed with curative intent in case of small lesions. The purpose of this study is to evaluate safety and efficacy of MWA of liver tumors with final ablation zone ≤5 mm from the heart.

METHODS

A retrospective review was conducted on patients with hepatic cancer who underwent MWA between 1/2015 and 6/2019. Patients with a final ablation zone ≤5 mm to the heart were included. For these patients, imaging obtained prior, during and after procedure along with procedure reports were used to identify tumor and ablation characteristics, and electronic medical records were used to identify patient demographics and disease status.

RESULTS

A total of 17 patients had liver tumors with ablation zone ≤5 mm to the heart. Mean lesion size was 18.2 mm (range, 10-33 mm) and mean follow-up period was 10.4 months. Of note 82% of patients had multifocal disease at time of MWA of lesion close to the heart. Two patients had pneumothorax, one of which required chest tube placement. None of the patients had cardiac arrhythmias or other complications. Overall 12/17 of the patients had disease progression within the liver at different sites from ablated lesions. One patient had residual disease and one had local recurrence. In addition, 4/17 patients, had no disease progression or recurrence and one underwent liver transplantation prior to follow-up imaging.

CONCLUSIONS

MWA of liver lesions with ablation zone ≤5 mm to the heart is safe and effective, however, it can be technically challenging.

Stereotactic and Robotic Minimally Invasive Thermal Ablation of Malignant Liver Tumors: A Systematic Review and Meta-Analysis

Background

Stereotactic navigation techniques aim to enhance treatment precision and safety in minimally invasive thermal ablation of liver tumors. We qualitatively reviewed and quantitatively summarized the available literature on procedural and clinical outcomes after stereotactic navigated ablation of malignant liver tumors.

Methods

A systematic literature search was performed on procedural and clinical outcomes when using stereotactic or robotic navigation for laparoscopic or percutaneous thermal ablation. The online databases Medline, Embase, and Cochrane Library were searched. Endpoints included targeting accuracy, procedural efficiency, and treatment efficacy outcomes. Meta-analysis including subgroup analyses was performed.

Results

Thirty-four studies (two randomized controlled trials, three prospective cohort studies, 29 case series) were qualitatively analyzed, and 22 studies were included for meta-analysis. Weighted average lateral targeting error was 3.7 mm (CI 3.2, 4.2), with all four comparative studies showing enhanced targeting accuracy compared to free-hand targeting. Weighted average overall complications, major complications, and mortality were 11.4% (6.7, 16.1), 3.4% (2.1, 5.1), and 0.8% (0.5, 1.3). Pooled estimates of primary technique efficacy were 94% (89, 97) if assessed at 1–6 weeks and 90% (87, 93) if assessed at 6–12 weeks post ablation, with remaining between-study heterogeneity. Primary technique efficacy was significantly enhanced in stereotactic vs. free-hand targeting, with odds ratio (OR) of 1.9 (1.2, 3.2) (n = 6 studies).

Conclusions

Advances in stereotactic navigation technologies allow highly precise and safe tumor targeting, leading to enhanced primary treatment efficacy. The use of varying definitions and terminology of safety and efficacy limits comparability among studies, highlighting the crucial need for further standardization of follow-up definitions.

Clinical evaluation of a robotic system for precise CT-guided percutaneous procedures

PURPOSE

To assess accuracy and compare protocols for CT-guided needle insertion for clinical biopsies using a hands-free robotic system, balancing system accuracy with duration of procedure and radiation dose.

METHODS

Thirty-two percutaneous abdominal and pelvic biopsies were performed and analyzed at two centers (Center 1 n = 11; Center 2 n = 21) as part of an ongoing prospective, multi-center study. CT datasets were obtained for planning and controlled placement of 17 g needles using a patient-mounted, CT-guided robotic system. Planning included target selection, skin entry point, and predetermined checkpoints. Additional CT imaging was performed at checkpoints to confirm needle location and permit stepwise correction of the trajectory. Center 1 used a more conservative approach with multiple checkpoints, whereas Center 2 used fewer checkpoints. Scanning and needle advancement were performed under respiratory gating. Accuracy, radiation dose, and steering duration were compared.

RESULTS

Overall accuracy was 1.6 ± 1.5 mm (1.9 ± 1.2 mm Center 1; 1.5 ± 1.6 mm Center 2; p = 0.55). Mean distance to target was 86.2 ± 27.1 mm (p = 0.18 between centers). Center 1 used 4.6 ± 0.8 checkpoints, whereas Center 2 used 1.8 ± 0.6 checkpoints (p < 0.001). Effective radiation doses were lower for Center 1 than for Center 2 (22.2 ± 12.6 mSv vs. 11.7 ± 4.3 mSv; p = 0.002). Likewise, steering duration (from planning to target) was significantly reduced in relation to the number of checkpoints from 43.8 ± 15.9 min for Center 1 to 30.5 ± 10.2 min for Center 2 (p = 0.008).

CONCLUSIONS

Accurate needle targeting with < 2 mm error can be achieved in patients when using a CT-guided robotic system. Judicious selection of the number of checkpoints may substantially reduce procedure time and radiation dose without sacrificing accuracy.

Percutaneous microwave ablation versus radiofrequency ablation of hepatocellular carcinoma: a meta-analysis of randomized controlled trials

PURPOSE

Percutaneous radiofrequency ablation (RFA) and microwave ablation (MWA) are well-validated interventions for hepatocellular carcinoma (HCC). The purpose of this study was to compare their safety and efficacy through a meta-analysis of randomized controlled trials (RCT).

METHODS

MEDLINE, Pubmed, and the Cochrane Library were queried up to September 2020 using the terms "microwave", "radiofrequency", "hepatocellular", and "randomized". Only RCTs investigating MWA versus RFA for HCC were included. Baseline study characteristics, complete ablation rate, ablation time, overall survival, local recurrence, and complication rates were investigated.

RESULTS

Among the five original studies included, a total of 413 and 431 patients were treated with RFA and MWA, respectively. All studies focused on very early and early-stage HCC only (Barcelona Clinic Liver Cancer Stage 0 and A). No statistical significance was observed in terms of complete ablation rate (96.7 vs 96.9%, p = 0.882), overall survival (6 month: 95.7 vs 100%, p = 0.492; 1 year: 91.9 vs 94.1%, p = 0.264; 3 year: 77.5 vs 78.4%, p = 0.905), recurrence-free survival (6 month: 99.1 vs 99.7%, p = 0.717; 1 year: 94.6 vs 93.9%, p = 0.675; 3 year: 76.8 vs 77.1%, p = 0.935), and complication rates (p > 0.05 in all types). The mean ablation time of MWA was significantly shorter than RFA (26.9 vs 14.1 min, p < 0.001).

CONCLUSION

For very early and early-stage HCC, RFA and MWA are equally safe and effective, though the former is associated with a longer ablation time.

High-intensity focused ultrasound ablation of liver tumors in difficult locations

High-intensity focused ultrasound (HIFU) has been shown to be a valuable tool in the management of small liver tumors such as hepatocellular carcinoma (HCC). It has been shown to be a safe and effective means to ablate small HCC even in the presence of advanced cirrhosis. This review examines the challenges faced during HIFU ablation when the target tumors are located in difficult locations such as the liver dome, close to the rib cage, near large blood vessels or the heart, or adjacent to hollow viscera; and the special maneuvers employed to tackle such lesions.

Advanced Techniques in the Percutaneous Ablation of Liver Tumours

Percutaneous ablation is an accepted treatment modality for primary hepatocellular carcinoma (HCC) and liver metastases. The goal of curative ablation is to cause the necrosis of all tumour cells with an adequate margin, akin to surgical resection, while minimising local damage to non-target tissue. Aside from the ablative modality, the proceduralist must decide the most appropriate imaging modality for visualising the tumour and monitoring the ablation zone. The proceduralist may also employ protective measures to minimise injury to non-target organs. This review article discusses the important considerations an interventionalist needs to consider when performing the percutaneous ablation of liver tumours. It covers the different ablative modalities, image guidance, and protective techniques, with an emphasis on new and advanced ablative modalities and adjunctive techniques to optimise results and achieve satisfactory ablation margins.

Right inferior phrenic artery; Don't miss on MDCT before chemoembolization of hepatic dome HCC

Background

Transarterial chemoembolization (TACE) is considered a standard local-regional treatment for intermediate-stage hepatocellular carcinoma (HCC) and the most common bridging therapy. HCC typically receives its blood supply from the hepatic artery; however, it can recruit a parasitic supply from extrahepatic collateral arteries. The right inferior phrenic artery (RIPA) is considered the most common extrahepatic collateral pathway supplying HCC and so interfere with the therapeutic efficacy of TACE resulting in treatment failure and poor outcome. Imaging by MDCT with angiography has an essential role in depicting the presence or absence of an EHC arterial supply during the pre-TACE evaluation. We analyzed MDCT studies with CT angiography of patients with hepatic dome HCC retrospectively to confirm the diagnosis of HCC and to assess its blood supply. All patients were subjected to a proper assessment by history, clinical examination, as well as routine laboratory investigations

Results

Our study includes 58 cases with hepatic dome HCC. On CT angiography, the extrahepatic collateral from the RIPA supplying hepatic dome HCC was detected in about 33 out of 58 cases (56.9%). The RIPA arose directly from the aorta in 30 cases (90.9%) with only three cases (9.1%) from the celiac trunk. All cases were managed with TACE with about 25 out of 33 cases (75.8%) with extrahepatic RIPA were undergone concomitant embolisation of both RIPA and hepatic artery during TACE procedure.

Conclusion

MDCT assesses well the HCC arterial supply which is fundamental for planning subsequent cannulation and embolization of extrahepatic RIPA supply to hepatic dome HCC.

Impact of anthropometric data on technical difficulty of laparoscopic liver of resections of segments 7 and 8: the CHALLENGE index

BACKGROUND

The high technical difficulty of using a laparoscopic approach to reach the posterosuperior liver segments is mainly associated with their poor accessibility. This study was performed to analyze correlations between anthropometric data and intraoperative outcomes.

STUDY DESIGN

All patients who underwent segmentectomy or wedge laparoscopic liver resection (LLR) of segments seven and/or eight from June 2012 to November 2019 were retrospectively analyzed. The exclusion criteria were intrahepatic cholangiocarcinoma, associated resection, multiple concomitant LLR, redo resection, and lack of preoperative imaging. Anthropometric data were correlated with intraoperative outcomes.

RESULTS

Forty-one patients (wedge resection, n = 32; segmentectomy, n = 9) were analyzed. A strong correlation was found between the craniocaudal liver diameter (CCliv) and liver volume (r = 0.655, p < 0.001). The anteroposterior liver diameter was moderately correlated with both the laterolateral abdominal diameter (LLabd) (r = 0.372, p = 0.008) and anteroposterior abdominal diameter (r = 0.371, p = 0.008). The body mass index (BMI) was not correlated with liver diameters. Women had a longer CCliv (p = 0.002) and shorter LLabd (p < 0.001) than men. The liver and abdominal measurements were combined to reduce this sex-related disparity. The CCliv/LLabd ratio (CHALLENGE index) was significantly correlated with the time of transection (r = 0.382, p = 0.037) and blood loss (r = 0.352, p = 0.029). The association between the CHALLENGE index and intraoperative blood loss was even stronger when considering only anatomical resection (r = 0.577, p = 0.048). A CHALLENGE index of > 0.4 (area under the curve, 0.757; p = 0.046) indicated a higher bleeding risk. The BMI predicted no intraoperative outcomes.

CONCLUSION

Anthropometric data rather than the BMI can help anticipate the difficulty of LLR of segments seven and eight.

Stereotactic Image-Guided Microwave Ablation for Malignant Liver Tumors-A Multivariable Accuracy and Efficacy Analysis

Background: Therapeutic success of thermal ablation for liver tumors depends on precise placement of ablation probes and complete tumor destruction with a safety margin. We investigated factors influencing targeting accuracy and treatment efficacy of percutaneous stereotactic image-guided microwave ablation (SMWA) for malignant liver neoplasms. Materials and methods: All consecutive patients treated with SMWA for malignant liver tumors over a 3-year period were analyzed. A computed tomography-based navigation system was used for ablation probe trajectory planning, stereotactic probe positioning, and validation of probe positions and ablation zones. Factors potentially influencing targeting accuracy [target positioning error (TPE)] and treatment efficacy within 6 months [ablation site recurrence (ASR)] were analyzed in a multivariable regression model, including challenging lesion locations (liver segments I, VII, and VIII; subphrenic location). Results: Three hundred one lesions (174 hepatocellular carcinomas, 87 colorectal liver metastases, 17 neuroendocrine tumors, and 23 others) were targeted in 191 interventions in 153 patients. The median TPE per ablation probe was 2.9 ± 2.3 mm (n = 384). Correction of ablation probe positions by repositioning was necessary in 4 out of 301 lesions (1%). Factors significantly influencing targeting accuracy were cirrhosis (R 0.67, CI 0.22-1.12) and targeting trajectory length (R 0.21, CI 0.12-0.29). Factors significantly influencing early ASR were lesion size >30 mm (OR 5.22, CI 2.44-11.19) and TPE >5 mm (OR 2.48, CI 1.06-5.78). Challenging lesion locations had no significant influence on targeting accuracy or early ASR. Conclusions: SMWA allows precise and effective treatment of malignant liver tumors even for lesions in challenging locations, with treatment efficacy depending on targeting accuracy in our model. Allowing for many tumors to be safely reached, SMWA has the potential to broaden treatment eligibility for patients with otherwise difficult to target tumors.

Targeted arsenite-loaded magnetic multifunctional nanoparticles for treatment of hepatocellular carcinoma

Arsenic trioxide (ATO), an FDA-approved drug for acute promyelocytic leukemia, also has great potential for treatment of solid tumors. Drug delivery powered by recent advances in nanotechnology has boosted the efficacy of many drugs, which is enlightening for applications of ATO in treating solid tumors. Herein, we reported arsenite-loaded multifunctional nanoparticles that are capable of pH-responsive ATO release for treating hepatocellular carcinoma (HCC) and real-time monitoring via magnetic resonance imaging. We fabricated these nanoparticles (designated as magnetic large-pore mesoporous silica nanoparticle (M-LPMSN)-NiAsO _x ) by loading nanoparticulate ATO prodrugs (NiAsO _x ) into the pores of large-pore mesoporous silica nanoparticles (LPMSNs) that contain magnetic iron oxide nanoparticles in the center. The surface of these nanodrugs was modified with a targeting ligand folic acid (FA) to further enhance the drug efficacy. Releasing profiles manifest the responsive discharging of arsenite in acidic environment. In vitro experiments with SMMC-7721 cells reveal that M-LPMSN-NiAsO _x -FA nanodrugs have significantly higher cytotoxicity than traditional free ATO and induce more cell apoptosis. In vivo experiments with mice bearing H22 tumors further confirm the superior antitumor efficacy of M-LPMSN-NiAsO _x -FA over traditional free ATO and demonstrate the outstanding imaging ability of M-LPMSN-NiAsO _x -FA for real-time tumor monitoring. These targeted arsenite-loaded magnetic mesoporous silica nanoparticles integrating imaging and therapy hold great promise for treatment of HCC, indicating the auspicious potential of LPMSN-based nanoplatforms.

One-lung ventilation to treat hepatic dome lesion - a further step towards minimally invasive surgery: a case report

Background

Although liver resection is still the best treatment for primary or metastatic hepatic lesions, a conventional surgical approach may be challenging in patients with a history of previous abdominal surgery. We present a case of a 58-year-old white man with paracaval, subdiaphragmatic, recurrent hepatocellular carcinoma; he had a history of multiple abdominal surgeries.

Methods

In select patients, percutaneous ultrasound-guided thermal ablation is a valid non-surgical alternative due to its safety, efficacy, and good tolerability. Hepatic lesions located in the posterosuperior segments, however, can be difficult to reach via a percutaneous approach.

Result

For these cases, one-lung left-sided ventilation may be particularly helpful in blocking the right hemidiaphragm and improving the acoustic window to the liver.

Conclusion

We present a case of paracaval, subdiaphragmatic, recurrent hepatocellular carcinoma in which the tumor was only reachable after one-lung left-sided ventilation that was successfully treated by percutaneous ultrasound-guided microwave ablation.

Percutaneous thermal ablation of hepatocellular carcinomas located in the hepatic dome using artificial carbon dioxide pneumothorax: retrospective evaluation of safety and efficacy

INTRODUCTION

The targeting of hepatocellular carcinomas (HCC) in the hepatic dome can be challenging during percutaneous thermal ablation (PTA). The aims of this study were (1) to evaluate the safety and efficacy of PTA of HCC in the hepatic dome that cannot be visualized under US, using artificial CO2 pneumothorax and CT-guidance and (2) to compare the results with US-visible HCC located in the liver dome treated under US-guidance.

MATERIALS

Over a 32-month period, 56 HCC located in the hepatic dome were extracted from a prospectively maintained database. Twenty-eight cases (US-guidance group) were treated under US-guidance, while the others (n = 28, CT-CO2 group) were treated under CT-guidance using artificial CO2 pneumothorax after lipiodol tagging of the tumor. The primary technical success and complications rates of this technique were retrospectively assessed. Local tumor progression (LTP), intrahepatic distant recurrence (IDR), local recurrence-free survival (LRFS) and overall survival (OS) were also compared between both groups.

RESULTS

Primary technical success was 100% in both groups. No major complications occurred. After a median follow-up of 13.8 months (range, 1-33.4 months), LTP occurred in 10.7% (3/28) in CT-CO2 vs. 25% (7/28) in the US-guidance group (p = NS). IDR occurred in 39.3% (11/28) in CT-CO2 vs. 28.6% (8/28) in the US-guidance group (p = NS). Death occurred in 17.9% (5/28) of patients in both groups. LRFS and OS did not significantly differ using Kaplan-Meier survival estimates.

CONCLUSION

CT-guided PTA after artificially induced CO2 pneumothorax is a safe and efficient technique to treat HCC located in the hepatic dome.