Unintended thermal injuries from radiofrequency ablation: organ protection with an angioplasty balloon catheter in an animal model

Safety and effectiveness of balloon catheter-assisted ultrasound-guided percutaneous microwave ablation in difficult-site liver cancer

BACKGROUND

Balloon catheter isolation is a promising auxiliary method for thermal ablation treatment of liver cancer. We aimed to explore the safety and effectiveness of balloon catheter isolation-assisted ultrasound-guided percutaneous microwave ablation (MWA) in treating liver cancer in difficult anatomical locations.

METHODS

Data of 132 patients with 145 difficult-site liver cancer treated with ultrasound-guided percutaneous MWA were retrospectively analyzed. Participants were classified into the isolation (n = 40) and non-isolation (n = 92) groups based on whether the patients were treated using a balloon catheter prior to ablation. The major complication rates, local tumor residuals (LTR), and tumor follow-up for local tumor progression (LTP) at 6 and 12 months post-ablation were compared between the two groups.

RESULTS

The rates of major postoperative complications did not significantly differ between the isolation and non-isolation groups (2.5% vs. 4.3%, P = 0.609). The postoperative LTR rates were significantly different between the isolation and non-isolation groups (4.8% vs. 17.5%, P = 0.032). Balloon catheter isolation [odds ratio (OR) = 0.225, 95% confidence interval (CI): 0.085-0.595, P = 0.009] and tumor diameter (OR = 2.808, 95% CI: 1.186-6.647, P = 0.019) were identified as independent factors influencing LTR rate. The cumulative LTP rates at 6 and 12 months after ablation showed no significant differences between the isolation and non-isolation groups (2.6% vs. 7.9%, P = 0.661; 4.9% vs. 9.8%, P = 0.676, respectively). Cox proportional hazards regression analysis showed that tumor diameter was an independent risk factor for cumulative LTP rate (OR = 3.445, 95% CI: 1.406-8.437, P = 0.017).

CONCLUSIONS

Balloon catheter isolation-assisted MWA was safe and effective in the treatment of difficult-site liver cancer. Additionally, tumor diameter significantly influenced LTR and LTP rates after ablation.

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.

Ultrasound for suspected Baker's cyst: A test of limited clinical value?

Introduction

Patients with posterior knee swellings are commonly encountered in clinical practice with the vast majority referred for an ultrasound scan to assess for a clinically suspected Baker's cyst.

Aims

Our aim was to determine the incidence of different pathologies in patients investigated for a posterior knee swelling of a clinically suspected Baker's cyst using ultrasound. We also wanted to investigate the incidence of significant pathologies in the popliteal fossa to assess whether the ultrasound scan findings influenced patient management.

Methodology

Retrospective analysis was performed on all patients who underwent an ultrasound scan for a suspected Baker's cyst or posterior knee swelling at our institution, between January 2017 and December 2018. Patient demographics, ultrasound findings, further imaging investigations and histopathology were recorded. Patient records were followed up for a minimum period of 3 years after ultrasound.

Results

A total of 680 patients had a posterior knee ultrasound scan. Of that, 51% (347/680) had a Baker's cyst and 40% (273/680) had a normal ultrasound scan. Sixty (9%) patients had other abnormalities identified within the popliteal fossa. Four patients had significant findings on ultrasound that required a change of management. No malignancies identified.

Conclusion

This study confirms the high incidence of Baker's cysts in patients presenting with a posterior knee swelling. In the absence of red flag symptoms, ultrasound of the posterior knee for a clinically suspected Baker's cyst is of limited clinical value.

Thermoprotection of Neural Structures During Musculoskeletal Ablation

Percutaneous thermal ablation is widely used for local control and palliation of a variety of lesions throughout the musculoskeletal system. In this setting, safe ablation is predicated on the avoidance of unintentional injury to vulnerable neural structures that are often in proximity to ablation targets. This article highlights key periprocedural considerations in musculoskeletal ablation and reviews the array of active and passive thermoprotective measures that are critical to safe and successful treatment.

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.

Efficacy and Safety of Angioplasty Balloon Interposition in CT-Guided Percutaneous Thermal Ablation of Hepatic Malignancies to Protect Adjacent Organs

PURPOSE

To evaluate the feasibility and safety of placing angioplasty balloons between the liver surface and adjacent organs in CT-guided thermal ablation of subcapsular liver malignancies in case of inadequate success of conventional dissection techniques.

MATERIALS AND METHODS

A retrospective, single-centre database query identified 327 hepatic malignancies in 153 patients treated in 215 sessions from 2016 to 2018 by thermal ablation. Demographic data, tumour size, distance to adjacent structures, complications and long-term outcomes were assessed when ancillary procedures were performed to protect adjacent organs.

RESULTS

In 21 of 327 (6.4%) ablations, thermal protection was necessary. Balloon interposition was successfully performed in 9 cases in 8 patients after hydrodissection or gas insufflation failed to separate adherent organs. Median pre- and post-balloon insertion distance was 0 mm [0-2 mm] and 17 mm [8-20 mm]. No balloons were damaged, ruptured or slid away from their initial position. Technical success of MWA and protection of adherent structures were achieved in all procedures. In a median follow-up of 11.5 months [0-49 months], the local control rate was 88.9% as 1 patient was treated twice with an interval of 3 months for local recurrence. Three non-process-related major complications and 1 minor complication occurred.

CONCLUSION

Balloon interposition is a safe and feasible method to enable thermal ablation to a greater number of patients, even after established thermo-protective techniques fail to separate the colon or stomach from the liver surface.

Guidewire-catheter induced hydrodissection to assist radiofrequency ablation for subcapsular hepatocellular carcinoma with iodized oil retention in patients with failed artificial ascites due to perihepatic adhesion

PURPOSE

We aimed to evaluate the usefulness of guidewire-catheter induced hydrodissection (GIH) to assist radiofrequency ablation (RFA) for subcapsular hepatocellular carcinoma (HCC) with iodized oil retention in patients with failed artificial ascites due to perihepatic adhesion.

METHODS

This retrospective study included 17 patients with small subcapsular HCC ineligible for ultrasonography-guided RFA who received RFA under guidance of fluoroscopy and cone-beam computed tomography immediately after iodized oil transarterial chemoembolization (TACE) between April 2011 and January 2016. In the study patients, creation of artificial ascites to protect the perihepatic structures failed due to perihepatic adhesion and GIH was attempted to separate the perihepatic structures from the ablation zone. The technical success rate of GIH, technique efficacy of RFA with GIH, local tumor progression (LTP), peritoneal seeding, and complications were evaluated.

RESULTS

The technical success rate of GIH was 88.24% (15 of 17 patients). Technique efficacy was achieved in all 15 patients receiving RFA with GIH. During an average follow-up period of 48.1 months, LTP developed in three patients. Cumulative LTP rates at 1, 2, 3, and 5 years were 13.3%, 20.6%, 20.6%, and 20.6%, respectively. No patient had peritoneal seeding. Two of the 15 patients receiving RFA with GIH had a CIRSE grade 3 liver abscess, but none had complications associated with thermal injury to the diaphragm or abdominal wall near the ablation zone.

CONCLUSION

GIH can be a useful method to assist RFA for subcapsular HCC with iodized oil retention in patients with failed artificial ascites due to perihepatic adhesion.

Adjunctive hydrodissection of the bare area of liver during percutaneous thermal ablation of sub-cardiac hepatic tumours

OBJECTIVE

To report the technique of hydrodissection of the sub-diaphragmatic bare area of the liver, in order to protect the diaphragm/heart during percutaneous thermal ablation (PTA) of sub-cardiac hepatic tumours.

MATERIALS AND METHODS

Between January 2016 and December 2018, five patients (four female, one male; mean age 56.2 years) with five sub-cardiac liver tumours (two hepatocellular carcinoma, three metastases; mean size 39 mm) abutting the bare area (segments II/IVA) with expected ablation zones ≤ 5 mm from the myocardium were treated with PTA and adjunctive hydrodissection. Time to perform hydrodissection, distance between superior hepatic and diaphragmatic/pericardial surfaces before and after hydrodissection, ablation efficacy, complications, and local tumour progression (LTP) at last imaging follow-up were recorded.

RESULTS

Technical feasibility was 100%, with mean hydrodissection-volume of 126 ml (range 80-200 ml) and median hydrodissection-time of 9 min (range 8-45 min). Liver-diaphragmatic and liver-pericardial distance increased, respectively, from 2.4 mm (range 0-8 mm) to 10.8 mm (range 6-19 mm) and from 4 mm (range 1-10 mm) to 12.6 mm (range 8-20 mm) post-hydrodissection. All procedures were performed at full-power with complete tumour ablation and without complications (including peri-procedural haemodynamic/electrocardiographic disturbances, pericardial effusion and diaphragmatic hernia) or evidence of LTP at mean 12.2-month (range 1-26 month) follow-up.

CONCLUSION

Hydrodissection of the sub-diaphragmatic bare area of the liver is technically feasible and may potentially optimize safety PTA of sub-cardiac hepatic tumours.

Value of artificial ascites to assist thermal ablation of liver cancer adjacent to the gastrointestinal tract in patients with previous abdominal surgery

Background

To evaluate the feasibility and effectiveness of artificial ascites to assist thermal ablation of liver cancer adjacent to the gastrointestinal tract in patients with previous abdominal surgery.

Methods

Thirty-nine patients with a total of 40 liver malignant tumors were enrolled between January 2016 and June 2019. All had histories of hepatectomy, splenectomy, cholecystectomy, and intestinal surgery. The distance between the tumor and the gastrointestinal tract was < 5 mm. Normal saline was used as artificial ascites to protect the gastrointestinal tract during thermal ablation. The success rate of the procedure, incidence of major complications, and the technical efficacy of ablation were recorded. Patients were followed for local tumor progression (LTP), and overall survival (OS).

Results

The use of artificial ascites was successful in 38 of the 40 procedures (95%). Major complications occurred in two of the 39 patients (5.1%) following the procedure. One was an intestinal fistula that occurred in a failed case and was associated with an infection. The other was a liver abscess that occurred in a successful case. The technical efficacy of ablation was 100% (40/40 procedures). The median follow-up was 16 months. The 1-, 2-, and 3-year LTP rates were 2.9, 5.7 and 5.7%. The 1-, 2-, and 3-year OS rates were 97.1, 86.8 and 69.5%.

Conclusion

In patients with previous abdominal surgery, artificial ascites is feasible and effective for assisting thermal ablation of liver cancer adjacent to the gastrointestinal tract.

Radiofrequency ablation following artificial ascites and pleural effusion creation may improve outcomes for hepatocellular carcinoma in high-risk locations

PURPOSE

To investigate the outcomes of radiofrequency ablation (RFA) following artificial ascites (AA) and artificial pleural effusion (AP) creation for hepatocellular carcinoma (HCC) in high-risk locations.

MATERIALS AND METHODS

Eligible patients were divided into 2 study periods (non-AAAP and AAAP groups) with AAAP performed in the latter period. Local tumor progression, primary technique effectiveness and complications were compared between patients with and without AAAP. Cumulative probability of local tumor progression and overall survival were estimated with Kaplan-Meier curves.

RESULTS

One hundred thirty-eight patients with 195 tumors were evaluated. AAAP was performed in 48 patients with 76 tumors. Local tumor progression rates at 12 and 24 months were 9.3% and 22.2% in the non-AAAP group versus 5.5% and 9% in the AAAP group (p < 0.0001). Primary technique effectiveness was achieved in 76.5% of the non-AAAP group versus 89.5% of the AAAP group (p = 0.046). Night (7.6%) major complications occurred in the non-AAAP group and 2 (2.6%) cases occurred in the AAAP group. Therapy-oriented severity grading system after RFA was lower in the AAAP group (p = 0.02). Overall survival rates at 12 and 24 months were 85.6% and 77.7% in the non-AAAP group versus 97.2% and 89.7% in the AAAP group (p = 0.033).

CONCLUSION

RFA following AA and AP for high-risk located HCC may improve outcomes.

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

Percutaneous hepatic interventions are generally safe given the fact that liver closely abuts the abdominal wall and hence it is easily accessible. However, the superior portion of liver, adjacent to the diaphragm, commonly referred as the “hepatic dome”, presents unique challenges for interventionists. Percutaneous access to the hepatic dome may be restricted by anatomical factors and special considerations may be required to avoid injury to the surrounding organs. The purpose of this review article is to discuss certain specific maneuvers and techniques that can enhance the success and safety of interventions in the hepatic dome.

Artificial ascites and pneumoperitoneum to facilitate thermal ablation of liver tumors: a pictorial essay

Image-guided percutaneous thermal ablation is increasingly utilized in the treatment of hepatic malignancies. Peripherally located hepatic tumors can be difficult to access or located adjacent to critical structures that can be injured. As a result, ablation of peripheral tumors may be avoided or may be performed too cautiously, leading to inadequate ablation coverage. In these cases, separating the tumor from adjacent critical structures can increase the efficacy and safety of procedures. Artificial ascites and artificial pneumoperitoneum are techniques that utilize fluid and gas, respectively, to insulate critical structures from the thermal ablation zone. Induction of artificial ascites and artificial pneumoperitoneum can enable complete ablation of otherwise inaccessible hepatic tumors, improve tumor visualization, minimize unintended thermal injury to surrounding organs, and reduce post-procedural pain. This pictorial essay illustrates and discusses the proper technique and clinical considerations for successful artificial ascites and pneumoperitoneum creation to facilitate safe peripheral hepatic tumor ablation.

Understanding patient options, utilization patterns, and burdens associated with breast cancer screening

Despite ongoing awareness, educational campaigns, and advances in technology, breast cancer screening remains a complex topic for women and for the health care system. Lack of consensus among organizations developing screening guidelines has caused confusion for patients and providers. The psychosocial factors related to breast cancer screening are not well understood. The prevailing algorithm for screening results in significant rates of patient recall for further diagnostic imaging or procedures, the majority of which rule out breast cancer rather than confirming it. For women, the consequences of the status quo range from unnecessary stress to additional out-of-pocket expenses to indirect costs that are more difficult to quantify. A more thoughtful approach to breast cancer screening, coupled with a research agenda that recognizes the indirect and intangible costs that women bear, is needed to improve cost and quality outcomes in this area.