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.
Ascites ; Bile Duct Diseases/etiology ; Carcinoma, Hepatocellular/*surgery/ultrasonography ; Catheter Ablation/adverse effects ; Humans ; Liver Neoplasms/*surgery/ultrasonography ; Neoplasm, Residual/etiology

Local ablation therapy is considered as a conventional treatment option for patients with early stage hepatocellular carcinoma (HCC). Although radiofrequency (RF) ablation is widely used for HCC, the use of cryoablation has been increasing as newer and safer cryoablation systems have developed. The thermodynamic mechanism of freezing and thawing used in cryoablation is the Joule-Thomson effect. Cryoablation destroys tissue via direct tissue destruction and vascular-related injury. A few recent comparative studies have shown that percutaneous cryoablation for HCCs is comparable to percutaneous RF ablation in terms of long term therapeutic outcomes and complications. Cryoablation has several advantages over RF ablation such as well visualization of iceball, no causation of severe pain, and lack of severe damage to great vessels and gallbladder. It is important to know the advantages and disadvantages of cryoablation compared with RF ablation for improvement of therapeutic efficacy and safety.
Carcinoma, Hepatocellular/diagnostic imaging/*surgery ; Catheter Ablation ; *Cryosurgery ; Humans ; Liver Neoplasms/diagnostic imaging/*surgery ; Magnetic Resonance Imaging ; Tomography, X-Ray Computed ; Ultrasonography

OBJECTIVETo investigate the therapeutic efficacy and its influencing factors of ultrasound-guided percutaneous radiofrequency ablation (PRFA) in the treatment of liver carcinoma.

METHODSWith a temperature-controlled multi-electrode needle, ultrasound-guided PRFA was employed to treat forty-seven patients with 67 tumor nodules, with a diameter of 2.6 +/- 1.1 cm (1.0 - 5.5 cm).

RESULTSA complete ablation (CA) rate of 80.6% was achieved in the present series, with a CA rate of 91.7% in the tumors < or = 3 cm in diameter, 75.0% in tumors from 3.1 to 4.0 cm, and 14.3% in tumors > 4 cm. The CA rate was significantly greater in tumors with a temperature rising up to 70 degrees C within the initial 2 minutes at ablation as compared with that longer than 2 minutes (P < 0.05). A markedly higher CA rate was obtained in tumors with an ablation-maintaining temperature of over 80 degrees C than that between 70 degrees C and 80 degrees C (P < 0.01). All patients were followed up with a mean time of 11.3 months. The local recurrence rate was 9.3% (5/54), and 1-year survival rate was 82.1%. Eighteen patients (38.3%) had a distant recurrence.

CONCLUSIONSThe tumor size, temperature-rising time and ablation-maintaining temperature represented the important factors affecting the therapeutic efficacy of PRFA.

Adult ; Aged ; Carcinoma, Hepatocellular ; diagnostic imaging ; surgery ; Catheter Ablation ; methods ; Female ; Humans ; Liver Neoplasms ; diagnostic imaging ; surgery ; Male ; Middle Aged ; Temperature ; Ultrasonography, Interventional

OBJECTIVETo assess the value of an infusion-based separation technique to assist in ultrasound (US)-guided percutaneous radiofrequency ablation (RFA) of liver cancers abutting the liver edge.

METHODSTwenty-four cases of malignant liver tumors abutting the hepatic edge were treated with US-guided puncture accompanied by the assistant infusion technique. The US-guided puncture was made with a 22-G needle through the hepatic tissue and into the abdominal cavity near the target tumor. Infusion of a saline solution was used to separate the liver from any surrounding structures so that percutaneous RFA could be safely performed. Complications, including gastrointestinal injury, hemorrhage and death, were recorded. Technical efficacy and safety were evaluated.

RESULTSAmong the 24 patients, the target tumors were adjacent to the right kidney (n=6), colon (n=6), stomach (n=5), pericardium (n=4), and gall bladder (n=3). Twenty-three patients received a successful radical percutaneous RFA with assistant infusion. The assistant infusion volumes ranged from 80-390 ml and created spaces ranging from 0.8-2.5 cm between the liver and surrounding structures. Five of the cases with tumors adjacent to the stomach or colon received the largest volume infusions. The infusion failed to create a separation space in only one case, due to the presence of an adhesion; as a result, this patient was treated with palliative RFA. The mean hospital stay for all 24 patients was four days after surgery. No severe complications or deaths occurred. At 1-month follow-up, computed tomography images showed that 22 cases had complete ablation, yielding a technical success rate of 95.7% (22/23). No needle track implantation was observed.

CONCLUSIONAssistant infusion for percutaneous radiofrequency ablation creates a protective space between the liver and surrounding structures in patients with liver tumors abutting the liver edge. This safe and effective assistant technique broadens the range of patients available for percutaneous RFA treatment.

Adult ; Aged ; Carcinoma, Hepatocellular ; surgery ; Catheter Ablation ; methods ; Female ; Humans ; Isotonic Solutions ; administration & dosage ; Liver Neoplasms ; surgery ; Male ; Middle Aged ; Treatment Outcome ; Ultrasonography, Interventional

OBJECTIVETo retrospectively investigate the feasibility of radiofrequency ablation (RFA) in treating advanced hepatocellular carcinoma (HCC) using standard ultrasound-guided percutaneous RFA.

METHODSA total of 655 patients with unresectable advanced HCC underwent ultrasound-guided percutaneous RFA therapy at our institution between July 2000 to September 2001. Ninety-two of those patients, representing 136 tumors, were selected for analysis based on the following criteria: presence of UICC/AJCC-TNM (6th edition) stage III and IV advanced HCC, (III: n=82 patients, with 126 tumors; IV: n=10 patients, with 10 tumors); extensive portal vein or inferior vena cava tumor thrombus; extrahepatic metastasis after surgical resection; and complete follow-up data. Follow-up consisted of enhanced computed tomography (CT) performed at one month post-RFA treatment, then every three months. Contrast-enhanced ultrasound (CEUS) was performed in 51 (55.4%) patients before RFA. The standard treatment using optimal strategies were applied in (72.8%) 67 patients. The established strategies included: (1) select RFA indications based on CEUS results; (2) design radical protocols based on invasive range showed by CEUS; (3) multiple overlapping ablations based on mathematical protocols; (4) two or three bipolar RFA electrodes with three-dimensional localization; (5) color ultrasound-guided percutaneous ablation of tumor feeding artery (PAA)/transcatheter arterial chemoembolization (TACE) + RFA for HCC with rich supply. The other 25 patients (27.2 %) were treated with conventional RFA protocols. The ablation procedure was considered a success if no abnormal enhancement or wash-out was detected in the treated area on the CT scan at one month. All patients had received liver protection treatments following RFA. Chi-squared test or Fisher's exact test were used to compare the early complete tumor necrosis rates and the local recurrence rates. Survival was estimated by Kaplan-Meier analysis and log-rank test. P less than 0.05 was considered statistically significant.

RESULTSThe RFA-treated tumors ranged in size from 1.5 to 7.0 cm (average: 4.5 cm). Fifty-nine patients had solitary tumor, and the remaining 33 had multiple tumors (2 to 4 tumors). Patients were classified by Child-Pugh score as A (n=58), B (n=32) and C (n=2). Early complete tumor necrosis rate after initial RFA was 90.4% (123/136 tumors). Serious complications developed in two patients (2.2%). No treatment-related death occurred. Follow-up ranged from 3-134 months. Local recurrence rate was 16.9% (23/136 tumors). The 1-, 3- and 5-year overall survival rates were 83.3%, 48.3% and 21.9%, respectively, and the median survival time was 35 months. Stratification analysis indicated the early complete tumor necrosis rate was higher in groups of patients with Child-Pugh A score (98.3%) , CEUS administration (98.0%), and standard treatment (97.0%). The local recurrence rate was lower in groups of patients with tumors less than or equal to 3.0 cm (5.9%), CEUS administration (11.8%), and standard treatment (16.4%). The 5-year survival was significantly higher in patients with Child-Pugh A, tumors less than or equal to 3.0 cm, CEUS administration, and standard treatment (all, P less than 0.05).

CONCLUSIONRFA treatment of patients with advanced HCC, tumors less than 7.0 cm, and without thrombosis in the main vessels was efficacious. The RFA treatment strategy and subsequent liver protection therapy in RFA may improve survival.

Adult ; Aged ; Aged, 80 and over ; Carcinoma, Hepatocellular ; pathology ; surgery ; Catheter Ablation ; methods ; Female ; Humans ; Liver Neoplasms ; pathology ; surgery ; Male ; Middle Aged ; Neoplasm Staging ; Retrospective Studies ; Ultrasonography, Interventional

We report in a 65-year-old man hepatocellular carcinoma adjacent to a transjugular intrahepatic portosystemic shunt stent-graft which was successfully treated with irreversible electroporation (IRE). IRE is a new non-thermal tissue ablation technique which uses electrical pulses to induce cell necrosis by irreversible membrane poration. IRE proved to be more advantageous in the ablation of perivascular tumor with little injury to the surrounding structures.
Aged ; Carcinoma, Hepatocellular/diagnosis/*surgery ; Electroporation/*methods ; Humans ; Liver Neoplasms/diagnosis/*surgery ; Magnetic Resonance Imaging ; Male ; *Portasystemic Shunt, Transjugular Intrahepatic ; *Stents ; Tomography, X-Ray Computed ; Ultrasonography, Doppler

OBJECTIVETo investigate the clinical value of enhanced ultrasonography before and after ultrasound guided radiofrequency ablation (RFA) of hepatomas.

METHODSEighteen patients with 17 primary hepatocellular carcinoma and 1 hepatic metastasis were studied. Sixteen were confirmed by operation or needle puncture biopsy, 2 by clinical examinations including CT scanning, MRI etc. New contrast agent, SonoVue, Technos DU6 and Contrast Tuned Imaging (CnTI) technique were adopted. Enhanced ultrasonography was performed before or after the RFA procedure.

RESULTSTwenty-six lesions were observed with enhanced ultrasonography before RFA, 24 of which showed ball-carrying sign or diffuse enhancement at the early artery phase favoring the fast diagnosis; 9 lesions showed feeding vessels; twelve of the 26 lesions (46.2%) tended to be larger, especially those with unclear margins (78.6%, 11/14) and those without halo sign (68.8%, 11/16). Enhanced ultrasonography revealed 13 satellite foci in four cases which had been undetectable with routine ultrasound, CT scanning or MRI. The final diagnosis of either inactivation or residual disease would rely upon more than two kinds of images, levels of tumor marks, biopsy pathology and more than 7 months of follow-up. Twenty-two lesions were observed with enhanced ultrasonography after RFA, with an accuracy of 95.5% (21/22), being similar to the enhanced CT and was significantly superior to the routine color ultrasonography whose accuracy was only 63.6% (14/22).

CONCLUSIONEnhanced ultrasonography may provide more information on the characters, size, number and feeding vessels of the tumor before radiofrequency ablation, thus helping choose the indicator, establish and carry out the treatment protocol. This technique may also help to assess the therapeutic response to RFA.

Adult ; Aged ; Carcinoma, Hepatocellular ; diagnostic imaging ; pathology ; surgery ; Catheter Ablation ; Female ; Humans ; Liver Neoplasms ; diagnostic imaging ; pathology ; surgery ; Male ; Middle Aged ; Ultrasonography

OBJECTIVETo assess the value of application of percutaneous radiofrequency ablation (RFA) with artificial hydrothorax for liver cancer in the hepatic dome.

METHODSThirty-two patients with 43 lesions of hepatic malignant tumors in the hepatic dome underwent ultrasound-guided percutaneous radiofrequency ablation (RFA) with artificial hydrothorax. Artificial hydrothorax was created by infusion of saline via an intrathoracically placed 14-G central venous catheter, which was ultrasound-guided percutaneously inserted before RFA, separating the right lung from the hepatic dome. The adverse reaction and therapeutic efficacy were also analyzed.

RESULTSIn the 32 patients with 43 lesions in the hepatic dome (4 tumors in segment IV 21 tumors in segment VII and 18 tumors in segment VIII), 18 lesions of 14 patients were not observed by ultrasound before the operation. Thirty-two patients received the ultrasound-guided placement of intrathoracical catheter, and (1606.3 ± 485.9) ml (1000 - 2500 ml) saline solution was infused successfully. After obtaining an image of the whole tumor, 31 patients received percutaneous RFA therapy on schedule, and 22 patients received percutaneous transdiaphragmatic RFA therapy. One patient with 2 lesions gave up the treatment, because one of his tumors was not detectable by ultrasound. Diaphragmatic muscle hemorrhage was seen in two patients, subcutaneous edema in two patients, and pneumothorax in one patient. All the complications were cured, and no serious complications or related death occurred. 1-month follow-up with contrast-enhanced CT/MRI images showed that 29 patients had complete ablation, and the effective rate of this technique was 93.5% (29/31).

CONCLUSIONSArtificial hydrothorax helps us not only to visualize the whole tumor in the hepatic dome, but also offers a transdiaphragmatic route for therapy. Ultrasound-guided percutaneous RFA with artificial hydrothorax is a feasible, safe, and effective technique for treating liver cancer in the hepatic dome and worthy of being promoted.

Adult ; Aged ; Carcinoma, Hepatocellular ; diagnostic imaging ; surgery ; Catheter Ablation ; methods ; Female ; Follow-Up Studies ; Humans ; Hydrothorax ; Liver Neoplasms ; diagnostic imaging ; surgery ; Male ; Middle Aged ; Sodium Chloride ; Ultrasonography, Interventional

The early assessment of the therapeutic response after percutaneous radiofrequency (RF) ablation is important, in order to correctly decide whether further treatment is necessary. The residual unablated tumor is usually depicted on contrast-enhanced multiphase helical computed tomography (CT) as a focal enhancing structure during the arterial and portal venous phases. Contrast-enhanced color Doppler and power Doppler ultrasonography (US) have also been used to detect residual tumors. Contrast-enhanced gray-scale US, using a harmonic technology which has recently been introduced, allows for the detection of residual tumors after ablation, without any of the blooming or motion artifacts usually seen on contrast-enhanced color or power Doppler US. Based on our experience and reports in the literature, we consider that contrast-enhanced gray-scale harmonic US constitutes a reliable alternative to contrast-enhanced multiphase CT for the early evaluation of the therapeutic response to RF ablation for liver cancer. This technique was also useful in targeting any residual unablated tumors encountered during additional ablation.
Adult ; Aged ; Carcinoma, Hepatocellular/radiography/*surgery/*ultrasonography ; *Catheter Ablation ; Contrast Media ; Female ; Humans ; Liver Neoplasms/radiography/*surgery/*ultrasonography ; Male ; Middle Aged ; Polysaccharides/diagnostic use ; Suspensions/diagnostic use ; Tomography, Spiral Computed ; Ultrasonography, Doppler/methods

OBJECTIVE: The aim of this study is to investigate the effects of cooperative training on the pretreatment assessment of the feasibility to perform Ultrasonography (US) guided percutaneous radiofrequency ablation for patients afflicted with hepatocellular carcinoma. MATERIALS AND METHODS: In our prospective study, 146 patients with 200 hepatocellular carcinomas were referred for radiofrequency ablation after triage by hepatologists. Three radiologists with different levels of experience performed the planning US before (group I) and after (group II) cooperative training, to evaluate whether radiofrequency ablation was feasible. The feasibility rates considered eligible according to our criteria were evaluated. In addition, we analyzed the reasons for the lack of feasibility were analyzed. The interobserver agreement for the assessment of feasibility before and after training was also calculated. RESULTS: The overall feasibility rates for both groups was 73%. No significant difference in the feasibility rates was observed. The feasibility rates of each observer for group I were 71% (observer 1), 77% (observer 2) and 70% (observer 3) and those for group II were 73%, 76% and 69%, respectively. In the tumors (n = 164) considered ineligible, the two most common causes for refraining from performing radiofrequency ablation included non-visualization of the tumor (62%) and the absence of a safe route for the percutaneous approach (38%). We found moderate interobserver agreement for all observers before cooperative training and a good agreement after training. CONCLUSION: Although the cooperative training did not affect the feasibility rate of each observer, it improved the interobserver agreement for assessing the feasibility of performing US guided radiofrequency ablation, which may reduce unnecessary admission or delayed treatment.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Hepatocellular/*surgery/ultrasonography ; *Catheter Ablation ; Clinical Competence ; Feasibility Studies ; Humans ; Inservice Training ; Liver Neoplasms/*surgery/ultrasonography ; Male ; Middle Aged ; Prospective Studies ; Reproducibility of Results ; *Ultrasonography, Interventional