Complications of radiofrequency coagulation of liver tumours

Various complications of percutaneous radiofrequency ablation for hepatic tumors: radiologic findings and technical tips

Radiofrequency ablation is a safe and effective treatment for primary and secondary liver malignancies and has a low complication rate; however, there are various radiofrequency ablation-related complications which can occur from the thorax to the pelvis. Although most of these complications are usually minor and self-limited, they may become fatal if diagnosis and treatment are delayed. It is important for radiologists performing radiofrequency ablation to have a perspective regarding the possible radiofrequency ablation-related complications and their risk factors as well as the radiologic findings for their timely detection and increase of the treatment efficacy, and thereby encouraging the use of the radiofrequency ablation technique. This article illustrates the various imaging features of common and rare radiofrequency ablation-related complications as well as offers technical tips in order to avoid these complications.

Patterns of complications following intraoperative radiofrequency ablation for liver metastases

BACKGROUND

Intraoperative radiofrequency ablation (IRFA) is added to surgery to obtain hepatic clearance of liver metastases. Complications occurring in IRFA should differ from those associated with wedge or anatomic liver resection.

METHODS

Patients with liver metastases treated with IRFA from 2000 to 2010 were retrospectively analysed. Postoperative outcomes are reported according to the Clavien-Dindo system of classification.

RESULTS

A total of 151 patients underwent 173 procedures for 430 metastases. Of these, 97 procedures involved IRFA plus liver resection and 76 involved IRFA only. The median number of lesions treated by IRFA was two (range: 1-11). A total of 123 (71.1%) procedures were carried out in patients who had received preoperative chemotherapy. The mortality rate was 1.2%. Thirty (39.5%) IRFA-only patients and 45 (46.4%) IRFA-plus-resection patients presented complications. Immediate complications (n = 4) were associated with IRFA plus resection. American Society of Anesthesiologists (ASA) class, previous abdominal surgery or hepatic resection, body mass index, number of IRFA procedures, portal pedicle clamping, total vascular exclusion and preoperative chemotherapy were not associated with a greater number of complications of Grade III or higher severity. Length of surgery >4 h [odds ratio (OR) 2.67, 95% confidence interval (CI) 1.1-6.3; P < 0.05] and an associated contaminating procedure (OR 3.72, 95% CI 1.53-9.06; P < 0.005) led to a greater frequency of complications of Grade III or higher.

CONCLUSIONS

Mortality and morbidity after IRFA, with or without resection, are low. Nevertheless, long interventions and concurrent bowel operations increase the risk for septic complications.

The pilot experience upon surgical ablation of large liver tumor by microwave system with tissue permittivity feedback control mechanism

BACKGROUND

Microwave ablation (MWA) is used to treat patients with unresectable liver cancer. Our institution applied a novel microwave generator capable of automatically adjusting energy levels based on feedback related to tissue permittivity. This approach is meant to facilitate ablations over larger areas and provide results of greater predictablility. This paper reports on the safety, efficacy, and feasibility of this new system in the treatment of patients with large liver tumors.

METHODS

Between July 2012 and December 2012, a total of 23 patients with malignant liver tumors exceeding 4 cm in diameter underwent surgical MWA using a 902-928 MHz generator. The proposed system used a 14-gauge antenna without internal-cooling. Follow up on tumor recurrence was performed using contrast-enhanced computed tomography or magnetic resonance imaging at 1 month and then at 3 month intervals for a period of at least 12 months following ablation.

RESULTS

Among the cancers treated, 10 were primary hepatocellular carcinomas (HCCs) and 13 were metastatic lesions from primary colorectal cancer (CRLM). The mean tumor size was 5.40 cm (range of 4.0-7.0 cm). A total of 18 patients underwent MWA via open surgery, and 5 received laparoscopic MWA. The mean ablation time was 1982 seconds, with a range of 900-3600 seconds, and the median number of ablation sessions was 2.0 (range of 1-4 sessions). The rate of complete ablation, as defined by a total loss of contrast-enhancement one month post-treatment, was 82.6% (19 of 23 patients), and the rate of local recurrence was 26.3% (5 of 19 patients). For tumors with a diameter of 4.0-7.0 cm, the technical success rate of MWA was higher for HCC patients (70%) than for metastatic liver cancer (53.8%) patients; however, the difference was not statistically significant. All patients survived throughout the observation period, and the morbidity rate was 8.6%.

CONCLUSIONS

MWA treatment using the proposed system with tissue permittivity feedback control resulted in a high rate of complete ablation and reduced morbidity. This approach proved to be a fast, easy, and effective option for the ablation of large liver cancers, particularly HCCs.

Safety and Efficacy of Ultrasound-Guided Radiofrequency Ablation of Recurrent Colorectal Cancer Liver Metastases after Hepatectomy

INTRODUCTION

To assess the results and outcome of radiofrequency ablation in the treatment of recurrent colorectal liver metastases.

PATIENTS AND METHODS

Between January 2005 and September 2012, we treated 59 patients with recurrent colorectal metastases not amenable to surgery with 77 radiofrequency ablation procedures. Radiofrequency was indicated if oncologic resection was technically not possible or the patient was not fit for major surgery. A total of 91 lesions were treated. The mean number of liver tumors per patient was 1.5, and the mean tumor diameter was 2.3 cm. In 37.5% of the cases, lesions had a subcapsular location, and 34% were close to a vascular structure.

RESULTS

The morbidity rate was 18.7%, and there were no post-procedural deaths. Distant extrahepatic recurrence appeared in 50% of the patients. Local recurrence at the site of ablation appeared in 18% of the lesions. Local recurrence rate was 6% in lesions less than 3 cm and 52% in lesions larger than 3 cm. The size of the lesions (more than 3 cm) was an independent risk factor for local recurrence (p < 0.05). Survival rates at 1, 3, and 5 years were 94.5%, 65.3%, and 21.7%, respectively.

DISCUSSION

Radiofrequency ablation is a safe procedure and allows local tumor control in lesions less than 30 mm (local recurrence of 6%) and provides survival benefits in patients with recurrent colorectal liver metastases.

Vessel patency post irreversible electroporation

PURPOSE

The purpose of the study was to evaluate the effect of Irreversible Electroporation (IRE) on vessel patency in close proximity to the ablation zone.

MATERIALS AND METHODS

Between January 2010 and November 2013, 101 patients underwent percutaneous IRE procedures using the NanoKnife for primary and metastatic tumors in different organs. Age ranged from 24 to 83 years. A total of 129 lesions were treated. [liver (100), pancreas (18), kidney (3), pelvis (1), aorto-caval lymph nodes (2), adrenal (2), lung (1), retroperitoneal (1), surgical bed of a prior Whipple procedure (1)]. Post treatment contrast-enhanced CT and MRI scans were reviewed to evaluate caliber, patency, and flow defects of vessels in close proximity to the ablation zone (defined as vessels within 0-1 cm from the treatment zone).

RESULTS

A total of 158 vessels were examined for patency on follow-up. The mean distance of the vessel from the treatment zone was 2.3 ± 2.5 mm. Ten vessels within the treatment zone were encased by tumor. Mean tumor size was 2.7 + 1.5 cm. Overall mean follow-up was 10.3 months. Abnormal vascular changes were noted in 7 of 158 (4.4%) vessels. No significant association was found between distances from the treatment zone and presence of narrowing/thrombosis at the follow-up imaging. (Mann-Whitney U, p = 0.772; logistic regression: p = 0.593; odds ratio: 0.908; CI 0.637-1.294).

CONCLUSION

This study demonstrates safety of IRE for the treatment of tumors near the large blood vessels and tumors already encasing the vessels. Further studies to substantiate these findings are essential to validate this crucial advantage of IRE.

Hospital-based, acute care encounters after radiofrequency ablation of hepatic tumours

BACKGROUND

The use of radiofrequency ablation (RFA) for cancer is increasing; however, post-discharge outcomes have not been well described. The aim of the present study was to determine rates of hospital-based, acute care utilization within 30 days of discharge after RFA.

METHODS

Using state-level data from California, patients were identified who were at least 40 years of age who underwent RFA of hepatic tumours without a concurrent liver resection from 2007-2011. Our primary outcome was hospital readmissions or emergency department visits within 30 days of discharge. A multivariable regression model was constructed to identify patient factors associated with these events.

RESULTS

The final sample included 1764 patients treated at 100 centres. Hospital readmissions (11.3/100 discharges), emergency department visits (6.0/100 discharges) and overall acute care utilization (17.3/100 discharges) were common. Most encounters occurred within 10 days of discharge for diagnoses related to the procedure. Patients with renal failure [adjusted odds ratio (AOR) = 1.98 (1.11-3.53)], obesity [AOR = 1.69 (1.03-2.77)], drug abuse [AOR = 2.95 (1.40-6.21)] or those experiencing a complication [AOR = 1.52 (1.07-2.15)] were more likely to have a hospital-based acute care encounter within 30 days of discharge.

CONCLUSIONS

Hospital-based acute care after RFA is common. Patients should be counselled regarding the potential for acute care utilization and interventions targeted to high-risk populations.

Colorectal hepatic metastasis: Evolving therapies

The approach for colorectal hepatic metastasis has advanced tremendously over the past decade. Multidrug chemotherapy regimens have been successfully introduced with improved outcomes. Concurrently, adjunct multimodal therapies have improved survival rates, and increased the number of patients eligible for curative liver resection. Herein, we described major advancements of surgical and oncologic management of such lesions, thereby discussing modern chemotherapeutic regimens, adjunct therapies and surgical aspects of liver resection.

Vasoconstriction by electrical stimulation: new approach to control of non-compressible hemorrhage

Non-compressible hemorrhage is the most common preventable cause of death on battlefield and in civilian traumatic injuries. We report the use of microsecond pulses of electric current to induce rapid constriction in femoral and mesenteric arteries and veins in rats. Electrically-induced vasoconstriction could be induced in seconds while blood vessels dilated back to their original size within minutes after stimulation. At higher settings, a blood clotting formed, leading to complete and permanent occlusion of the vessels. The latter regime dramatically decreased the bleeding rate in the injured femoral and mesenteric arteries, with a complete hemorrhage arrest achieved within seconds. The average blood loss from the treated femoral artery during the first minute after injury was about 7 times less than that of a non-treated control. This new treatment modality offers a promising approach to non-damaging control of bleeding during surgery, and to efficient hemorrhage arrest in trauma patients.

Vascular and interventional radiology radiofrequency ablation of benign thyroid nodules and recurrent thyroid cancers: literature review

Thermal radiofrequency ablation is a relatively new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. Different recommendations are necessary for the optimal use of radiofrequency ablation for thyroid nodules. These recommendations are based on a comprehensive analysis of the current literature, the results of multicenter studies, and expert consensus.

Prediction of aggressiveness in early-stage hepatocellular carcinoma for selection of surgical resection

BACKGROUND & AIMS

In early-stage hepatocellular carcinoma (eHCC), radiofrequency ablation (RFA) has comparable outcomes to surgical resection (SR); however, micrometastases may be present, resulting in tumor recurrence after local ablation. Therefore, we investigated predictors of aggressiveness in eHCC to select patients at high risk of recurrence after RFA who would benefit from SR.

METHODS

First, we analyzed 128 patients with newly diagnosed eHCC (single tumor with a diameter <3 cm) who underwent SR between January 2006 and December 2011. Risk factors for micrometastasis (representative of tumor aggressiveness) such as microvascular invasion or poor histologic grade were investigated. We then analyzed 201 eHCC patients who underwent RFA between July 2007 and December 2011. Identified risk factors were validated to determine their influence on tumor recurrence.

RESULTS

The only significant risk factor for tumor aggressiveness in the SR group was the product of serum levels of α-fetoprotein (AFP) and prothrombin induced by vitamin K absence-II (PIVKA-II) (A∗P ≥1600; hazard ratio [HR] 4.764; 95% confidence interval [CI], 1.867-12.161; p=0.001). This product also showed statistical significance for predicting recurrence in the RFA group (HR 2.296; 95% CI, 1.237-4.262; p=0.008). Patients with RFA and A∗P ≥1600 had significant early tumor recurrence (p=0.008) and poor late survival outcomes (p=0.001) compared with other patients.

CONCLUSIONS

The product of AFP and PIVKA-II levels is a useful predictor of aggressiveness in eHCC, which predicts tumor recurrence after RFA. Therefore, it should be considered when selecting SR as first-line treatment.

Successful percutaneous radiologic management of renal cell carcinoma tumor seeding caused by percutaneous biopsy performed before ablation

A case is reported of the successful image-based detection, diagnosis, and percutaneous ablation of tumor seeding in a 61-year-old man that was caused by percutaneous biopsy of a renal cell carcinoma performed before cryoablation and was not detected until 4 years after the biopsy procedure. Although tumor seeding is a rare complication after percutaneous biopsy or ablation, this case emphasizes the importance of imaging surveillance of the needle tract used during both biopsy and ablation procedures, provides guidance on measures that can be used to minimize the occurrence of tumor seeding, and demonstrates that entirely radiologic management can be successful.

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.

Irreversible electroporation for nonthermal tumor ablation in the clinical setting: a systematic review of safety and efficacy

PURPOSE

To provide an overview of current clinical results of irreversible electroporation (IRE), a novel, nonthermal tumor ablation technique that uses electric pulses to induce cell death, while preserving structural integrity of bile ducts and vessels.

METHODS

All in-human literature on IRE reporting safety or efficacy or both was included. All adverse events were recorded. Tumor response on follow-up imaging from 3 months onward was evaluated.

RESULTS

In 16 studies, 221 patients had 325 tumors treated in liver (n = 129), pancreas (n = 69), kidney (n = 14), lung (n = 6), lesser pelvis (n = 1), and lymph node (n = 2). No major adverse events during IRE were reported. IRE caused only minor complications in the liver; however, three major complications were reported in the pancreas (bile leak [n = 2], portal vein thrombosis [n = 1]). Complete response at 3 months was 67%-100% for hepatic tumors (93%-100% for tumors o 3 cm). Pancreatic IRE combined with surgery led to prolonged survival compared with control patients (20 mo vs 13 mo) and significant pain reduction.

CONCLUSIONS

In cases where other techniques are unsuitable, IRE is a promising modality for the ablation of tumors near bile ducts and blood vessels. This articles gives an extensive overview of the available evidence, which is limited in terms of quality and quantity. With the limitations of the evidence in mind, IRE of central liver tumors seems relatively safe without major complications, whereas complications after pancreatic IRE appear more severe. The available limited results for tumor control are generally good. Overall, the future of IRE for difficult-to-reach tumors appears promising.

Radiofrequency ablation for colorectal liver metastases

The management of hepatic metastases from colorectal cancer (HMCRC) is multimodal including chemotherapy, surgical resection, radiation therapy, and focused destruction technologies. Radiofrequency ablation (RFA) is the most commonly used focused destruction technology. It represents a therapeutic option that may be potentially curative in cases where surgical excision is contra-indicated. It also increases the number of candidates for surgical resection among patients whose liver metastases were initially deemed unresectable. This article explains the techniques, indications, and results of radiofrequency ablation in the treatment of hepatic colorectal metastases.

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

OBJECTIVES

The aim of this study was to investigate a novel approach of using a balloon catheter as a protective device to separate liver from the diaphragm or nearby bowel during radiofrequency ablation (RFA) of hepatic dome tumors in an animal model.

MATERIALS AND METHODS

All experimental procedures were approved by animal Institutional Review Board. Using a 3 cm RF needle electrode, 70 hepatic ablation zones were created using ultrasound in 7 pigs. 50 lesions were created using balloon interposition between liver and diaphragm; 20 lesions were created using the balloon device interposed posteriorly between liver and bowel. Additional 21 control lesions were performed. Animals were sacrificed immediately; diaphragm and bowel were then visually inspected and sectioned. Diaphragmatic and bowel injury was then classified according to the depth of thickness.

RESULTS

Control lesions caused full thickness injury, either to diaphragm or bowel. During ablation of lesions with balloon interposition, there was significantly less diaphragmatic injury, P < 0.001 and less bowel injury, P < 0.01.

CONCLUSION

Using balloon interposition as a protective device has advantages over previous saline infusion or CO2 insufflation, providing a safe way to expand percutaneous RFA of liver tumors located on the undersurface of the diaphragm. In addition, this method may be used in protection of other organs adjacent to areas being ablated.

Multidisciplinary treatment of patients with hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common malignancies in the world. When it is diagnosed, patients can choose from among several potentially curative treatments, such as surgical resection, transplantation, ablation therapy and transcatheter arterial chemoembolization. This review will give an overview of the present management of hepatocellular carcinoma. Liver transplantation is considered the best curative option, achieving a high rate of complete response, especially in patients with small hepatocellular carcinoma and good residual liver function. However, a shortage of donor livers restricts the availability of transplantation. In addition, only a minority of patients with hepatocellular carcinoma can be treated surgically, owing to impaired hepatic reserve, multiple intrahepatic lesions, extrahepatic lesions and the inability to obtain an optimal tumor-free margin. Therefore, for most patients, other types of interventions (transcatheter arterial chemoembolization, percutaneous ethanol injection and radiofrequency ablation) have been developed. Among them, two local ablative modalities, percutaneous ethanol injection and percutaneous radiofrequency ablation, have been accepted as the only potentially curative nonsurgical treatments for hepatocellular carcinoma. Radiofrequency ablation may become a standard nonsurgical treatment option for patients with early hepatocellular carcinoma.

Percutaneous radiofrequency ablation of hepatocellular lesions in segment II of the liver: a risk factor for cardiac tamponade

Percutaneous radiofrequency ablation (PRFA) is a minimally invasive procedure used for the treatment of small hepatocellular carcinomas. PRFA is regarded as a much safer alternative to surgical resection or orthotopic liver transplantation. However, serious complications, including cardiac tamponade, have been reported. Two cases of severe cardiac tamponade during PRFA were successfully treated.

First-line radiofrequency ablation with or without artificial ascites for hepatocellular carcinomas in a subcapsular location: local control rate and risk of peritoneal seeding at long-term follow-up

AIM

To compare the long-term local control of hepatocellular carcinoma (HCC) and risk of peritoneal seeding via percutaneous radiofrequency ablation (RFA) using artificial ascites with those of RFA without artificial ascites.

MATERIALS AND METHODS

The Institutional Review Board approved this retrospective study. From April 2005 to February 2008, 160 patients (121 men, 39 women; age range 36-79 years) with a single subcapsular HCC (mean size 2.19 cm) were treated with ultrasonography-guided percutaneous RFA as a first-line therapy. Forty-four patients were treated with RFA using artificial ascites, whereas the other 116 patients were treated without artificial ascites. The cumulative local tumour progression (LTP) and peritoneal seeding were compared in both groups using follow-up computed tomography (CT). Cumulative LTP rates were analysed using the Kaplan-Meier method and the log-rank test. Risk of peritoneal seeding was investigated by means of multivariate analysis.

RESULTS

The overall median follow-up period was 52.5 months (range 13-76 months). The 1, 2, 4, and 6 year cumulative LTP rates were 17.1, 27.6, 35.2, and 35.2%, respectively, in the group with artificial ascites, and 8, 15.2, 26.6, and 34.4% in the group without artificial ascites, without significant difference (p = 0.332). The rates of peritoneal seeding were 6.8% (3/44) in the group with artificial ascites and 2.6% (3/116) in the group without artificial ascites, a non-significant difference (p = 0.347). The biopsy prior to RFA was the independent risk factor of peritoneal seeding regardless of the use of artificial ascites.

CONCLUSION

Long-term local tumour control and risk of peritoneal seeding were comparable for RFA with or without artificial ascites when used as a first-line therapy for subcapsular HCC.

Percutaneous radiofrequency ablation versus partial hepatectomy for small centrally located hepatocellular carcinoma

BACKGROUND

It is not known whether percutaneous radiofrequency ablation (PRFA) could get the same treatment efficacy and fewer complications as partial hepatectomy (PH) in patients with small centrally located hepatocellular carcinoma (HCC). The present study was designed to evaluate the efficacy of PH and PRFA in the treatment of small centrally located HCC.

METHODS

From January 2002 until December 2007, 196 patients with small centrally located HCC (≤5 cm) were included. Of these 196 patients, 94 received PRFA and 102 patients were treated with PH. Treatment outcomes, including major complications and survival data, were studied.

RESULTS

No treatment-related death occurred in either group. There were no significant differences in survival rates between the two groups. The 1-, 3-, and 5-year disease-free survival rates for the PRFA and PH groups were 57.9%, 36.4%, 34.0%, and 59.8%, 42.4%, 40.8%, respectively (P = 0.50). The 1-, 3-, and 5-year overall survival rates for the two groups were 94.3%, 74.7%, and 49.8%, and 89.2%, 74.1%, and 63.1%, respectively (P = 0.96). PRFA had a lower rate of major complications than PH (8.5 vs. 19.6%), and the hospital stay was also shorter in the PRFA group than in the PH subgroup (4 vs. 13 days).

CONCLUSIONS

Based on the data obtained, we concluded that PRFA might be equal to PH for the treatment of small centrally located HCC. However, PRFA has the benefits of shorter hospital stay as well as a lower rate of complications.

Radiofrequency ablation for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common causes of cancer-related mortality worldwide. Unfortunately, only 20% of HCC patients are amenable to curative therapy (liver transplantation or surgical resection). Locoregional therapies such as radiofrequency ablation (RFA), percutaneous ethanol injection, microwave coagulation therapy, and transcatheter arterial chemoembolisation play a key role in the management of HCC. The choice of the treatment modality depends on the size of the tumour, tumour location, anatomic considerations and the number of tumours present and liver function. RFA therapy for HCC can be performed safely using a percutaneous, laparoscopic, or an open approach, even in patients with poor functional reserve. Since the introduction of RFA, several randomised controlled trials and non-randomised studies comparing RFA and other therapies for HCC have been conducted. In addition, in the last decade there have been technical advances in RFA therapy for HCC, resulting in significant improvement in the prognosis of HCC patients treated with this modality. In this review, we primarily focus on percutaneous RFA therapy for HCC and refer to current knowledge and future perspectives for this therapy. We also discuss new emerging ablation techniques.

Percutaneous radiofrequency ablation versus surgical radiofrequency ablation for malignant liver tumours: the long-term results

BACKGROUND

Radiofrequency ablation (RFA) has been used to treat hepatocellular carcinoma (HCC) and liver metastases for more than 10 years with promising early outcomes. Preliminary results comparing percutaneous and surgical approaches have shown no difference in short-term outcomes. In this study, the longer-term outcomes were presented.

METHODS

Patients with liver malignancies treated by RFA were prospectively studied from 2003 to 2011. Post-ablation assessment by computed tomography (CT) scan and serum biochemistry was performed at regular intervals. Recurrence rates and long-term survival were analysed.

RESULTS

A total of 233 patients with liver malignancies (75.5% HCC and 24.5% liver metastases) were analysed. Three RFA approaches were used (percutaneous 58.4%, laparoscopic 9.4% and open 32.2%). The median follow-up time was 29 months. Complete ablation was achieved in 83.7%, with no difference between the two approaches. More wound and chest complications were observed in the surgical group. Intra-hepatic recurrences were observed in 69.5%; extra-hepatic recurrences were detected in 22.3%, with no difference between the two groups. There was no statistical difference between the two approaches in overall 1-, 3- and 5-year survival.

CONCLUSION

An extended period of follow-up in patients with liver malignancies showed that RFA is an effective treatment. No difference was demonstrated between the percutaneous and surgical approach, in terms of recurrence and survival.

Survival analysis of high-intensity focused ultrasound ablation in patients with small hepatocellular carcinoma

BACKGROUND

High-intensity focused ultrasound (HIFU) ablation is a non-invasive treatment for hepatocellular carcinoma (HCC). At present, data on the treatment's long-term outcome are limited. This study analysed the survival outcome of HIFU ablation for HCCs smaller than 3 cm.

PATIENTS AND METHODS

Forty-seven patients with HCCs smaller than 3 cm received HIFU treatment between October 2006 and September 2010. Fifty-nine patients who received percutaneous radiofrequency ablation (RFA) were selected for comparison. The two groups of patients were compared in terms of pre-operative variables and survival.

RESULTS

More patients in the HIFU group patients had Child-Pugh B cirrhosis (34% versus 8.5%; P = 0.001). The 1- and 3-year overall survival rates of patients whose tumours were completely ablated in the HIFU group compared with the RFA group were 97.4% versus 94.6% and 81.2% versus 79.8%, respectively (P = 0.530). The corresponding 1- and 3-year disease-free survival rates were 63.6% versus 62.4% and 25.9% versus 34.1% (P = 0.683).

CONCLUSIONS

HIFU ablation is a safe and effective method for small HCCs. It can achieve survival outcomes comparable to those of percutaneous RFA and thus serves as a good alternative ablation treatment for patients with cirrhosis.

Microwave ablation of liver metastases to overcome the limitations of radiofrequency ablation

PURPOSE

The purpose of our study was to evaluate technical success, effectiveness and safety of microwave ablation (MWA) in patients with unresectable liver metastases, where radiofrequency ablation (RFA) presents some limits.

MATERIALS AND METHODS

Twenty-five patients (17 men, 8 women) with 31 liver metastases >3 cm or located near vessels (>3 mm) were treated in a total of 29 sessions. Tumours were subdivided as follows: colorectal metastases (n=21) and no colorectal metastases (n=10). All procedures were performed percutaneously under ultrasound (US) guidance. Follow-up was performed with computed tomography (CT) scan at 1, 3, 6 and 12 months after treatment; mean follow-up period was 12.04 (range, 3-36) months. Technical success, mean disease-free survival, effectiveness and safety were evaluated.

RESULTS

Technical success was obtained in all cases. Mean disease-free survival was of 20.5 months. Local recurrence was recorded in 12.9% of metastases treated (4/31). No major complications were recorded. The rate of minor complications was 44.8% (13/29 sessions). Mortality at 30 days was 0%.

CONCLUSIONS

Percutaneous MWA of liver metastases >3 cm or located near vessels (>3 mm) can be considered a valid and safe option, probably preferable to RFA. Further studies are required to confirm these encouraging initial results.

Liver radiofrequency ablation compromises the biological gut barrier

AIM

Liver radiofrequency ablation (RFA) has been shown to disrupt the mechanical component of the gut barrier. The aim of the present study was to investigate the consequences of liver RFA on the biological gut barrier in terms of the effects of bile production rate and bowel inflammatory state on intestinal microflora balance.

METHOD

A total of 25 New Zealand rabbits were assigned to five groups (n = 5 per group): group CBD: subjected to common bile duct (CBD) extracorporeal bypass; group CBD-RFA: subjected to CBD bypass plus one session of open liver RFA; group RFA: subjected to liver RFA; group sham: subjected to sham operation; and group TBD: subjected to total bile deviation (TBD). In groups CBD and CBD-RFA, bile production rate was assessed for 48 h. In groups sham and RFA, measurement of biliary glycine conjugates of cholic and deoxycholic acid levels, histopathologic examination of the non-ablated liver tissue, morphometric analysis, and histopathologic examination of the terminal ileum and microbiological analysis of fecal and tissue samples collected from the jejunum and the cecum (and in group TBD) were performed at 48 h post-operation.

RESULTS

One session of liver RFA resulted in ablation of 18.7 ± 2.7% of liver weight. Following liver RFA, bile production rate was reduced, while the levels of biliary bile salts were not affected. There was mild injury of the non-ablated liver parenchyma, mild intestinal wall inflammation, intestinal mucosa atrophy, and intestinal microbial population overgrowth.

CONCLUSION

Reduced in bile production and mild bowel inflammation secondary to liver RFA impaired the biological gut barrier as manifested by intestinal microflora imbalance.

Hepatitis B virus reactivation after radiofrequency ablation or hepatic resection for HBV-related small hepatocellular carcinoma: a retrospective study

BACKGROUND AND PURPOSE

Reactivation of hepatitis B virus (HBV) happens after systemic chemotherapy, transarterial chemoembolization (TACE) or hepatic resection for HBV-related hepatocellular carcinoma (HCC) patients. The incidence and risk factors of HBV reactivation after radiofrequency ablation (RFA) are unclear.

PATIENTS AND METHODS

From August 2006 to August 2011, 218 consecutive patients with HBV-related small HCC treated with RFA (n = 125) or hepatic resection (n = 93) were retrospectively studied. The incidence of HBV reactivation and risk factors were analyzed.

RESULTS

HBV reactivation developed in 20 (9.2%) patients after treatment. The incidence of HBV reactivation was significantly lower in the RFA group (5.6%, 7/125) than the hepatic resection group (14.0%, 13/93, P = 0.034). On univariate and multivariate analyses, no antiviral therapy (OR 11.7; 95% CI 1.52-90.8, P = 0.018) and treatment with RFA/hepatic resection (OR3.36; 95% CI 1.26-8.97, P = 0.016) were significant risk factors of HBV reactivation. On subgroup analysis, the incidence of HBV reactivation was lower in patients who received antiviral therapy than those who did not receive antiviral therapy in both the hepatic resection group (2.9% vs. 20.7%, P = 0.027) and the RFA group (0% vs. 7.6%, P = 0.188), although the difference was not significant in the latter group.

CONCLUSION

The incidence of HBV reactivation after RFA was relatively low when compared with hepatic resection. Prophylactic antiviral therapy is recommended, especially for patients who are going to receive hepatic resection for HBV-related HCC to decrease the incidence of post-treatment HBV reactivation.

Diaphragmatic necrosis after radiofrequency ablation of hepatocellular carcinoma: a successful surgical repair

We report a case of complete hemidiaphragmatic necrosis with liver abscess complicating radiofrequency ablation of a large subdiaphragmatic hepatocellular carcinoma in a patient with unrecognized history of endoscopic oddi sphincterotomy. At 2-year follow-up after surgical repair using a pedicled latissimus dorsi flap, clinical examination and imaging did not show complication or cancer recurrence. The risk of complete hemidiaphragmatic necrosis resulting from both thermal and septic injuries should be considered when radiofrequency ablation is performed for liver dome tumors, particularly in patients with impaired oddi sphincter. In this septic situation, a latissimus dorsi flap appears as the unique opportunity to repair the injured hemidiaphragm.

[Radiofrequency ablation of hepatocellular carcinoma]

Percutaneous radiofrequency ablation (RFA) is well established in the treatment of hepatocellular carcinoma (HCC). Due to its curative potential, it is the method of choice for non resectable BCLC (Barcelona Liver Clinic) 0 and A. RFA challenges surgical resection for small HCC and is the method of choice in bridging for transplantation and recurrence after resection or transplantation. The technical feasibility of RFA depends on the size and location of the HCC and the availability of ablation techniques (one needle techniques, multi-needle techniques). More recently, stereotactic multi-needle techniques with 3D trajectory planning and guided needle placement substantially improve the spectrum of treatable lesions including large volume tumors. Treatment success depends on the realization of ablations with large intentional margins of tumor free tissue (A0 ablation in analogy to R0 resection), which has to be documented by fusion of post- with pre-ablation images, and confirmed during follow-up imaging.

Radiofrequency ablation for postoperative recurrences of intrahepatic cholangiocarcinoma

OBJECTIVE

Most recurrent intrahepatic cholangiocarcinoma (RICC) lost the opportunity of radical resection while most nonsurgical management failed to prolong patients' survival. The efficacy and safety of radiofrequency ablation (RFA) as a local treatment for recurrent hepatocellular carcinoma have been confirmed by many clinical studies. The purpose of this study was to evaluate the efficacy, long-term survival and complications of RFA for RICC.

METHODS

A total of 12 patients with 19 RICCs after radical resection were included in this study. The tumors were 1.9-6.8 cm at the maximum diameter (median, 3.2±1.6 cm). All patients were treated with ultrasound guided RFA. There were two RFA approaches including percutaneous and open.

RESULTS

A total of 18 RFA treatment sessions were performed. Ablation was successful (evaluated by 1-month CT after the initial RFA procedure) in 18 (94.7%) of 19 tumors. By a median follow-up period of 29.9 months after RFA, 5 patients received repeated RFA because of intrahepatic lesion recurrence. The median local recurrence-free survival period and median event-free survival period after RFA were 21.0 months and 13.0 months, respectively. The median overall survival was 30 months, and the 1- and 3-year survival rates were 87.5% and 37.5%, respectively. The complication rate was 5.6% (1/18 sessions). The only one major complication was pleural effusion requiring thoracentesis.

CONCLUSION

This study showed RFA may effectively and safely manage RICC with 3-year survival of 37.5%. It provides a treatment option for these RICC patients who lost chance for surgery.

Postoperative neutrophil-to-lymphocyte ratio change predicts survival of patients with small hepatocellular carcinoma undergoing radiofrequency ablation

BACKGROUND

An elevated preoperative neutrophil-to-lymphocyte ratio (NLR) has been reported to be a prognostic factor for hepatocellular carcinoma (HCC) patients after treatment. However, the clinical implication of postoperative NLR change remains unclear.

MATERIALS AND METHODS

From May 2005 to Aug 2008, a cohort of consecutive 178 small HCC patients treated with radiofrequency ablation (RFA) was retrospectively reviewed. The NLR was recorded within 3 days before and 1 month after RFA. Baseline characteristics, overall survival (OS) and recurrence free survival (RFS) were compared according to preoperative NLR and/or postoperative NLR change. Prognostic factors were assessed by multivariate analysis.

RESULTS

Compared with preoperative NLR level, postoperative NLR decreased in 87 patients and increased in 91 patients after RFA. No significant differences were identified between two groups in commonly used clinic-pathologic features. The 1, 3, 5 years OS was 98.8%, 78.6%, 67.1% for NLR decreased group, and 92.2%, 55.5%, 35.4% for NLR increased group respectively (P<0.001); the corresponding RFS was 94.2%, 65.2%, 33.8% and 81.7%, 46.1%, 12.4% respectively (P<0.001). In subgroup analysis, the survival of patients with lower or higher preoperative NLR can be distinguished more accurate by postoperative NLR change. Multivariate analysis showed that postoperative NLR change, but not preoperative NLR, was an independent prognostic factor for both OS (P<0.001, HR = 2.39, 95%CI 1.53-3.72) and RFS (P = 0.003, HR = 1.69, 95%CI 1.87-8.24).

CONCLUSION

The postoperative NLR change was an independent prognostic factor for small HCC patient undergoing RFA, and patients with decreased NLR indicated better survival than those with increased NLR.

Postoperative neutrophil-to-lymphocyte ratio change predicts survival of patients with small hepatocellular carcinoma undergoing radiofrequency ablation

BACKGROUND

An elevated preoperative neutrophil-to-lymphocyte ratio (NLR) has been reported to be a prognostic factor for hepatocellular carcinoma (HCC) patients after treatment. However, the clinical implication of postoperative NLR change remains unclear.

MATERIALS AND METHODS

From May 2005 to Aug 2008, a cohort of consecutive 178 small HCC patients treated with radiofrequency ablation (RFA) was retrospectively reviewed. The NLR was recorded within 3 days before and 1 month after RFA. Baseline characteristics, overall survival (OS) and recurrence free survival (RFS) were compared according to preoperative NLR and/or postoperative NLR change. Prognostic factors were assessed by multivariate analysis.

RESULTS

Compared with preoperative NLR level, postoperative NLR decreased in 87 patients and increased in 91 patients after RFA. No significant differences were identified between two groups in commonly used clinic-pathologic features. The 1, 3, 5 years OS was 98.8%, 78.6%, 67.1% for NLR decreased group, and 92.2%, 55.5%, 35.4% for NLR increased group respectively (P<0.001); the corresponding RFS was 94.2%, 65.2%, 33.8% and 81.7%, 46.1%, 12.4% respectively (P<0.001). In subgroup analysis, the survival of patients with lower or higher preoperative NLR can be distinguished more accurate by postoperative NLR change. Multivariate analysis showed that postoperative NLR change, but not preoperative NLR, was an independent prognostic factor for both OS (P<0.001, HR = 2.39, 95%CI 1.53-3.72) and RFS (P = 0.003, HR = 1.69, 95%CI 1.87-8.24).

CONCLUSION

The postoperative NLR change was an independent prognostic factor for small HCC patient undergoing RFA, and patients with decreased NLR indicated better survival than those with increased NLR.

Effectiveness, safety, and local progression after percutaneous laser ablation for hepatocellular carcinoma nodules up to 4 cm are not affected by tumor location

OBJECTIVE

A high-risk location--defined as the tumor margin being less than 5 mm from large vessels or vital structures--represents a well-known limitation and contraindication for radiofrequency ablation of hepatocellular carcinoma (HCC) nodules. The aim of this study was to verify whether HCC nodule location negatively affected the outcome of percutaneous laser ablation in terms of its primary effectiveness, safety, and ability to prevent local tumor progression.

MATERIALS AND METHODS

The medical records and radiologic examinations of 164 cirrhotic patients (90 men, 74 women; mean age ± SD, 68.6 ± 8.3 years) with 182 HCC nodules 4 cm or smaller (mean diameter ± SD, 2.7 ± 0.78 cm) that had been treated by laser ablation between 1996 and 2008 were retrospectively analyzed. One hundred six patients had 116 nodules in high-risk sites (high-risk group), whereas 58 patients had 66 tumors located elsewhere (standard-risk group).

RESULTS

The overall median follow-up was 81 months (range, 6-144 months). The initial complete ablation rate per nodule did not significantly differ between the high-risk group and the standard-risk group (92.2% vs 95.5%, respectively; p = 0.2711). Rates of major complications (high-risk group vs standard-risk group, 1.9% [including one death] vs 0%) and minor complications (5.6% vs 1.0%) were not statistically different between the two groups. Only side effects were recorded significantly more often in high-risk patients than in standard-risk patients (31.5% vs 19.8%; p = 0.049). There was no significant difference in either cumulative incidence of local tumor progression (p = 0.499) or local tumor progression-free survival (p = 0.499, log rank test) between the high-risk group and the standard-risk group.

CONCLUSION

When laser ablation is used to treat small HCC nodules, tumor location does not have a significant negative impact on the technique's primary effectiveness or safety or on its ability to achieve local control of disease.

Locoregional surgical and interventional therapies for advanced colorectal cancer liver metastases: expert consensus statements

Selection of the optimal surgical and interventional therapies for advanced colorectal cancer liver metastases (CRLM) requires multidisciplinary discussion of treatment strategies early in the trajectory of the individual patient's care. This paper reports on expert consensus on locoregional and interventional therapies for the treatment of advanced CRLM. Resection remains the reference treatment for patients with bilateral CRLM and synchronous presentation of primary and metastatic cancer. Patients with oligonodular bilateral CRLM may be candidates for one-stage multiple segmentectomies; two-stage resection with or without portal vein embolization may allow complete resection in patients with more advanced disease. After downsizing with preoperative systemic and/or regional therapy, curative-intent hepatectomy requires resection of all initial and currently known sites of disease; debulking procedures are not recommended. Many patients with synchronous primary disease and CRLM can safely undergo simultaneous resection of all disease. Staged resections should be considered for patients in whom the volume of the future liver remnant is anticipated to be marginal or inadequate, who have significant medical comorbid condition(s), or in whom extensive resections are required for the primary cancer and/or CRLM. Priority for liver-first or primary-first resection should depend on primary tumour-related symptoms or concern for the progression of marginally resectable CRLM during treatment of the primary disease. Chemotherapy delivered by hepatic arterial infusion represents a valid option in patients with liver-only disease, although it is best delivered in experienced centres. Ablation strategies are not recommended as first-line treatments for resectable CRLM alone or in combination with resection because of high local failure rates and limitations related to tumour size, multiplicity and intrahepatic location.

Use of radiofrequency ablation in benign thyroid nodules: a literature review and updates

Successful thermal ablation using radiofrequency has been reported in various tumors including liver or kidney tumors. Nonsurgical minimally invasive ablative therapy such as radiofrequency ablation (RFA) has been reported to be a safe and efficient treatment option in managing symptomatic cold thyroid nodules or hyperfunctioning thyroid nodules. Pressure and cosmetic symptoms have been shown to be significantly improved both in the short and long terms after RFA. For hyperfunctioning thyroid nodules, RFA is indicated for whom surgery or radioiodine are not indicated or ineffective or for those who refuse surgery or radio-iodine. Improvement of thyroid function with decreased need for antithyroid medications has been reported. Complication rate is relatively low. By reviewing the current literature, we reported its efficacy and complications and compared the efficacy of RFA relative to other ablative options such as ethanol ablation and laser ablation.

Case-control study of the RFA therapeutic effect of newly developed 4D US and conventional 2D US

PURPOSE

For radiofrequency ablation (RFA) therapy of hepatocellular carcinoma (HCC), accurate positioning of the inserted needle in the index tumor seems to be an important factor affecting therapeutic effect. In a case-control study, we compared the therapeutic effect of RFA using 4D and 2D ultrasonography (US) to evaluate whether 4D US is more effective.

METHODS

Twenty subjects treated with percutaneous RFA using 4D US (4D group) and 20 subjects using conventional 2D US (2D group), who were matched for age, sex, and HCC diameter, were enrolled in this study. Aplio XG was used as the US system and PVT-375MV as the newly developed 4D US probe. The therapeutic effect of RFA was classified into four grades (A-D: "Grade A" is "absolutely curative").

RESULTS

In the 2D group, Grade A was achieved in 12 subjects (60 %). In contrast, Grade A was achieved in 19 subjects (95 %) in the 4D group. The proportion of cases in which Grade A was achieved was significantly higher in the 4D group (P < 0.01).

CONCLUSIONS

By using a 4D US device for RFA, more accurate insertion could be achieved and more effective therapy could be performed.

Radiofrequency ablation of liver metastases from colorectal cancer: a literature review

Liver metastases occur in up to 60% of patients with colorectal cancer, and the control of liver metastases is considered to be of primary importance because it is a critical factor in determining prognosis. Radiofrequency ablation (RFA) therapy is one of the least invasive techniques for unresectable hepatic malignancies and can be performed safely using percutaneous, laparoscopic, or open surgical techniques. The local tumor progression rates after RFA for colorectal liver metastases range from 8.8% to 40.0%, and 5-year survival rates range from 20.0% to 48.5%. No prospective, randomized trials comparing the efficacy of RFA with that of surgical resection for colorectal liver metastases are currently available. However, some retrospective studies have reported that patients who received RFA had a survival rate similar to that observed in surgically treated groups, while other studies have reported better survival among patients who underwent surgical resection. The use of a laparoscopic or open surgical approach allows the repeated placement of RFA electrodes at multiple sites to ablate larger tumors. An accurate evaluation of treatment response is very important for the success of RFA therapy because a sufficient safety margin (at least 0.5 cm) can prevent local tumor progression. This review critically summarizes the current status of RFA for liver metastases from colorectal cancer.

Clinical evaluation of a new technique to monitor return electrode skin temperature during radiofrequency ablation

PURPOSE

Return electrode burns occur occasionally in cardiac radiofrequency ablation and more frequently in tumor radiofrequency ablation. A return electrode incorporating a thermochromic liquid crystal (TLC) layer, which changes color with temperature, has been shown in sheep studies to accurately indicate underlying skin temperature. We aimed to validate the accuracy of TLC-coated return electrodes in indicating skin temperature in the clinical setting of cardiac radiofrequency ablation.

METHODS AND RESULTS

The top layer of a standard return electrode was replaced with TLC. Fluoro-optic thermometer (FOT) probes were laid on the skin side of the return electrode, which was then placed on the left lateral mid-thigh of 18 patients (mean age = 61 ± 12 years, 12 men) undergoing cardiac radiofrequency ablation. Return electrode photographs were taken when FOT temperature exceeded 35 °C. TLC color changes, observed in 11 patients, were converted to temperature and compared with FOT temperature. TLC temperature correlated well with FOT temperature (Pearson's coefficient = 0.97 ± 0.03). Bland-Altman analysis showed good agreement (mean temperature difference = -0.04 ± 0.08 °C, upper limit of agreement = 0.11 ± 0.005 °C, lower limit of agreement = -0.19 ± 0.005 °C). The maximum FOT temperature recorded was 39.6 °C. There was no thermal injury at the return electrode site on any patients, when assessed immediately after and the day following the procedure.

CONCLUSION

TLC-coated return electrodes accurately indicate underlying skin temperature in cardiac radiofrequency ablation and may help prevent burns. This technology might be essential in high energy radiofrequency ablation.

Effectiveness of impedance monitoring during radiofrequency ablation for predicting popping

AIM: To retrospectively evaluate the effectiveness of impedance monitoring for predicting popping during radiofrequency ablation (RFA) using internally cooled electrodes.

METHODS: We reviewed 140 patients (94 males, 46 females; age range 73.0 ± 11.1 year) who underwent RFA between February 2006 and November 2008 with a modified protocol using a limited power delivery rather than a conventional one to avoid popping. All the patients provided their written informed consent, and the study was approved by the institutional review board. Intraprocedural impedances were measured for the study subjects, and the tumors were classified into three types according to the characteristics of their impedance curves: increasing, flat, or decreasing. The tumors were further sorted into seven subtypes (A-G) depending on the curvature of the impedance curve’s increase or decrease. Relative popping rates were determined for the three types and seven subtypes. A chi-square test was performed to estimate statistical significance.

RESULTS: A total of 148 nodules treated by RFA were analyzed. The study samples included 132 nodules of hepatocellular carcinoma, 14 nodules of metastatic liver cancer, and two nodules of intrahepatic cholangiocarcinoma. The numbers of nodules with each impedance curve type were as follows: 37 increasing-type nodules, 43 flat-type nodules, and 68 decreasing-type nodules. Popping occurrence rates were 24.3%, 46.5% and 64.7%, respectively. Flat-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules (P = 0.039). Decreasing-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules (P < 0.0001). Notably, nodules that showed a sharp decrease in impedance in the latter ablation period (subtype E) exhibited a significantly higher rate of popping compared to other subtypes.

CONCLUSION: Intraprocedural impedance monitoring can be a useful tool to predict the occurrence of popping during liver tumor RFA performed with internally cooled electrodes.

Complications of radiofrequency ablation for hepatocellular carcinoma in a multicenter study: An analysis of 16 346 treated nodules in 13 283 patients

AIM

  We surveyed multiple centers to identify types and frequency of complications and mortality rate associated with radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC).

METHODS

  We distributed a questionnaire developed by members of the Chugoku-Shikoku Society for the Local Ablation Therapy of Hepatocellular Carcinoma to 20 centers and analyzed types and frequency of complications and mortality rate.

RESULTS

  In total, 16 346 nodules were treated in 13 283 patients between January 1999 and November 2010. Five patients (0.038%) died: two from intraperitoneal hemorrhage, and one each from hemothorax, severe acute pancreatitis and perforation of the colon. In 16 346 treated nodules, 579 complications (3.54%) were observed, including 78 hemorrhages (0.477%), 276 hepatic injuries (1.69%), 113 extrahepatic organ injuries (0.691%) and 27 tumor progressions (0.17%). The centers that treated a large number of nodules and performed RFA modifications, such as use of artificial ascites, artificial pleural effusion and bile duct cooling, had low complication rates.

CONCLUSION

  This study confirmed that RFA is a low-risk treatment for HCC and that sufficient experience and technical skill can reduce complications.

Tolerance of high-intensity focused ultrasound ablation in patients with hepatocellular carcinoma

BACKGROUND

High-intensity focused ultrasound (HIFU) ablation is a relatively new, noninvasive way of ablation for treating hepatocellular carcinoma (HCC). Emerging evidence has shown that it is effective for the treatment of HCC, even in patients with poor liver function. There is currently no data on the safety limit of HIFU ablation in patients with cirrhosis. However, this information is vital for the selection of appropriate patients for the procedure. We analyzed HCC patients who had undergone HIFU ablation and determined the lower limit of liver function and other patient factors with which HCC patients can tolerate this treatment modality.

METHODS

Preoperative variables of 100 patients who underwent HIFU ablation for HCC were analyzed to identify the risk factors in HIFU intolerance in terms of stress-induced complications. Factors that may contribute to postablation complications were compared.

RESULTS

Thirteen (13 %) patients developed a total of 18 complications. Morbidity was mainly due to skin and subcutaneous tissue injuries (n = 9). Five patients had first-degree skin burn, one had second-degree skin burn, and three had third-degree skin burn. Four complications were grade 3a in the Clavien classification and 14 were below this grade. Univariate analysis showed that age (p = 0.022) was the only independent factor in HIFU intolerance.

CONCLUSIONS

HIFU ablation is generally well tolerated in HCC patients with cirrhosis. It is safe for Child-Pugh A and B patients and selected Child-Pugh C patients. With this new modality, HCC patients who were deemed unsalvageable by other surgical means in the past because of simultaneous Child-Pugh B or C disease now have a new hope.

Tract seeding following radiofrequency ablation for hepatocellular carcinoma: prevention, detection, and management

Radiofrequency ablation (RFA) has become an important tool in the armamentarium of interventional oncology, particularly in the treatment of primary hepatocellular carcinoma and metastatic tumors. This procedure has proven to be an effective adjunct in treating hepatic tumors as a bridge to liver transplantation, and has a low complication profile. Although adverse events are rare and usually minor, a notable negative outcome is dissemination and implantation of viable tumor cells into the route of applicator entry, or tract seeding. Counter to the goal of treating a patient's cancer, this results in metastatic disease. In this report, the authors present 2 cases of tract seeding after RFA, methods of detection, and means of reducing the incidence of this relatively rare, but significant, complication.

Radiofrequency ablation complicated by skin burn

Radiofrequency (RF) ablation has been increasingly utilized as a minimally invasive treatment for primary and metastatic liver tumors, as well as tumors in the kidneys, bones, and adrenal glands. The development of high-current RF ablation has subsequently led to an increased risk of thermal skin injuries at the grounding pad site. The incidence of skin burns in recent studies ranges from 0.1-3.2% for severe skin burns (second-/third-degree), and from 5-33% for first-degree burns.(1-3).

Thermal tumor ablation therapy for colorectal cancer hepatic metastasis

Surgical resection for colorectal hepatic metastases (CRHM) is the preferred treatment for suitable candidates, and the only potentially curative modality. However, due to various limitations, the majority of patients with CRHM are not candidates for liver resection. In recent years, there has been an increasing interest in the role of thermal tumor ablation (TTA) as a component of combined resection-ablation strategies, staged hepatic resections, or as standalone adjunct treatment for patients with CRHM. Thus, ablative approaches have expanded the group of patients with CRHM that may benefit from liver-directed treatment strategies.