Laparoscopic in situ ablation of liver cancer with cryotherapy and radiofrequency ablation

Thermal Ablation in the Liver: Heat versus Cold-What Is the Role of Cryoablation?

Cryoablation is commonly used in the kidney, lung, breast, and soft tissue, but is an uncommon choice in the liver where radiofrequency ablation (RFA) and microwave ablation (MWA) predominate. This is in part for historical reasons due to serious complications that occurred with open hepatic cryoablation using early technology. More current technology combined with image-guided percutaneous approaches has ameliorated these issues and allowed cryoablation to become a safe and effective thermal ablation modality for treating liver tumors. Cryoablation has several advantages over RFA and MWA including the ability to visualize the ice ball, minimal procedural pain, and strong immunomodulatory effects. This article will review the current literature on cryoablation of primary and secondary liver tumors, with a focus on efficacy, safety, and immunogenic potential. Clinical scenarios when it may be more beneficial to use cryoablation over heat-based ablation in the liver, as well as directions for future research, will also be discussed.

Comparison of combined transarterial chemoembolization and ablations in patients with hepatocellular carcinoma: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis compares the efficacy of three combination therapies, including transarterial chemoembolization (TACE) with radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CRA) for the treatment of patients with hepatocellular carcinoma (HCC).

METHODS

Online databases, including Scopus, Web of Science, PubMed, Embase, CNKI, Google Scholar, and Cochrane Library were searched.

RESULTS

Forty-two studies with 5468 pooled patients (TACE + RFA: 21 studies with 3398 patients, TACE + MWA:14 studies with 1477 patients, and TACE + CRA: 7 studies with 593 patients) reported combination therapy versus TACE alone. The TACE + MWA subcohort had the best odds of long-term overall survival (OR 4.81, 95% CI 1.44, 16.08, P = 0.011) and objective response rate (OR 3.93, 95% CI 2.34, 6.61, P < 0.001) compared with the other two combination subcohorts. The TACE + RFA and TACE + MWA subcohorts had approximately similar odds of 1-year recurrence-free survival (OR 5.21, 95% CI 2.13, 12.75, P < 0.001 and OR 4.61, 95% CI 1.70, 12.51, P = 0.003, respectively). The disease control rate was similar between the TACE + MWA and TACE + CRA subcohorts (OR 4.01, 95% CI 2.66, 6.04, P < 0.001 and OR 4.05, 95% CI 1.68, 9.74, P = 0.002) but greater than the TACE + RFA subcohort (OR 3.23, 95% CI 2.14, 4.86, P < 0.001).

CONCLUSION

Overall, the TACE + MWA subcohort had the best efficacy and outcomes, especially for younger patients (less than 60-year-old) with tumor size of ≤ 3 cm, compared with the TACE + RFA or TACE + CRA subcohorts.

Microwave ablation combined with hepatectomy for treatment of neuroendocrine tumor liver metastases

BACKGROUND

Hepatectomy is the first choice for treating neuroendocrine tumor liver metastases. However, most patients with neuroendocrine tumor liver metastases are not suitable for hepatectomy. Ablation combined with hepatectomy can be an alternative to liver resection.

AIM

To explore the clinical effect of microwave ablation combined with hepatectomy for the treatment of neuroendocrine tumor liver metastases.

METHODS

In this study, the data of patients who underwent microwave ablation combined with hepatectomy for the treatment of neuroendocrine tumor liver metastases from June 2015 to January 2018 were reviewed. Before the operation, the patients did not receive any treatment for liver neuroendocrine tumors. After a multidisciplinary expert group discussion, all patients were deemed unsuitable for liver resection. All patients were diagnosed with neuroendocrine tumors by pathology. The overall survival time and progression-free survival time were followed by telephone calls and outpatient visits after surgery.

RESULTS

Eleven patients with neuroendocrine tumor liver metastases were treated by microwave ablation combined with hepatectomy between June 2015 and January 2018. The median number of liver metastatic nodules was 4 (range, 2 to 43). The median number of lesions resected was 1 (range, 1 to 18), and the median number of lesions ablated was 3 (range, 1 to 38). The mean operation time was 405.6 (± 39.4) min. The median intraoperative blood loss was 600 mL (range, 50 to 3000). Ten patients had a fever after surgery. The median duration of fever was 3 d (range, 0 to 21). Elevated bilirubin levels occurred in all patients after surgery. The median bilirubin on the first day after surgery was 28.5 (range, 10.7 to 98.9) µmol/L. One patient developed respiratory failure, renal insufficiency, and pneumonia after the operation. No patient died postoperatively during hospitalization. The mean overall survival time after surgery was 34.1 (± 3.7) mo, and the median progression-free survival time was 8 (range, 2 to 51) mo. One year after surgery, ten patients survived and five patients survived without progression. Three year after surgery, eight patients survived and two patients survived without progression.

CONCLUSION

Microwave ablation combined with hepatectomy not only makes the patients obtain a survival rate similar to that of patients undergoing hepatectomy, but also has a low incidence of postoperative complications.

Overall survival and local recurrence following RFA, MWA, and cryoablation of very early and early HCC: a systematic review and Bayesian network meta-analysis

OBJECTIVE

To compare overall survival (OS) and local recurrence (LR) following radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation (CA) for very early and early hepatocellular carcinoma (HCC).

METHODS

This systematic review was performed according to the PRISMA guidelines. MEDLINE, Embase, and Cochrane databases were searched. Randomized controlled trials (RCTs) and observational studies were included. OS and LR at 1 year and 3 years were assessed. OS was reported as hazard ratio (HR) with 95% credible intervals (CrI) and LR as relative risk (RR) with 95% CrI, to summarize effect of each comparison.

RESULTS

Nineteen studies (3043 patients), including six RCTs and 13 observational studies, met inclusion criteria. For OS at 1 year, as compared to RFA, CA had HR of 0.81 (95% CrI: 0.43-1.51), and MWA had HR of 1.01 (95% CrI: 0.71-1.43). For OS at 3 years, as compared to RFA, CA had HR of 0.90 (95% CrI: 0.48-1.64) and MWA had HR of 1.07 (95% CrI: 0.73-1.50). For LR at 1 year, CA and MWA had RR of 0.75 (95% CrI: 0.45-1.24) and 0.93 (95% CrI: 0.78-1.14), respectively, as compared to RFA. For LR at 3 years, CA and MWA had RR of 0.96 (0.74-1.23) and 0.98 (0.87-1.09), respectively, as compared to RFA. Overall, none of the comparisons was statistically significant. Age of patients and tumor size did not influence treatment effect.

CONCLUSIONS

RFA, MWA, and CA are equally effective for locoregional treatment of very early and early HCC.

KEY POINTS

• There is no significant difference in the OS and LR (at 1 year and 3 years) following ablation of very early and early HCC with RFA, MWA, and CA. • There was no effect of tumor size on the treatment efficacy. • More RCTs comparing CA with RFA and MWA should be performed.

Percutaneous Cryoablation of Liver Tumors: Initial Experience from a Tertiary Care Center in India

BACKGROUND

Percutaneous ablation is an important part of management strategy for liver tumors. While radiofrequency ablation and microwave ablation are the most widely used ablative techniques, cryoablation (CA) has several technical advantages but has been underused till recently. In this study, we report the initial experience with percutaneous CA of liver tumors.

METHODS

This was a retrospective evaluation of consecutive patients with liver tumors who underwent percutaneous CA between October 2018 and August 2019. The ablation procedures were performed under combined ultrasound and computed tomography guidance using argon-helium-based CA systems. The baseline tumor characteristics (including size and location), Barcelona Clinic Liver Cancer stage, and Child-Pugh score were recorded. Each patient underwent a follow-up after 1 month and at 3 months subsequently. Technical success, complete response, local tumor progression, and overall survival were evaluated.

RESULTS

Nine patients (mean age, 62.4 years, median age, 66 years, five men and four women) with 10 liver tumors (mean size, 2.22 cm) underwent CA. Seven (77.8%) patients had hepatocellular carcinoma (HCC), and 2 patients had solitary liver metastasis. One patient with HCC had two lesions, while the rest had only one lesion. Of the two metastatic lesions, one was from carcinoma of the cervix and the other was from jejunal neuroendocrine tumor. Five tumors were located adjacent to the gallbladder, two lesions were adjacent to the right portal vein, two lesions were subcapsular, and one lesion was adjacent to the stomach. Technical success was achieved in all the patients. Complete response was achieved in 7 (77.8%) patients. The median follow-up period was 7 months (range, 3-12 months). There was no local tumor progression and no death during the follow-up period. No procedure-related complication was seen.

CONCLUSION

Percutaneous CA of hepatic tumors is technically feasible and is a safe and effective ablative technique.

Comparison of Clinical Efficacy and Complications Between Laparoscopic Partial and Open Partial Hepatectomy for Liver Carcinoma: A Meta-Analysis

OBJECTIVE

To contrast the clinical effects and complications for the treatment of liver carcinoma in laparoscopic partial hepatectomy (LPH) and open partial hepatectomy (OPH).

METHODS

The multiple databases were adopted to search relevant studies, and the articles eventually satisfying the inclusion criteria were included. All the meta-analyses were conducted with the Review Manager 5.3, and to estimate the quality of each article risk of bias table was performed.

RESULTS

In the end, 17 studies including 3897 patients were involved, which eventually satisfied the eligibility criteria. The number of samples in LPH group and OPH group were 1723 and 2174, respectively. The results of heterogeneity test suggested that recurrence rate (odds ratio [OR] = -20.11, 95% confidence interval, CI [-35.93 to -4.29], P = .01; P for heterogeneity <.00001, I² = 100%), hospital days (mean difference (MD) = -2.21, 95% CI [-2.53 to -1.88], P < .000001; P for heterogeneity = .41, I² = 58%), and blood loss (MD = -68.09, 95% CI [-85.07 to -51.11], P < .00001; P for heterogeneity = .13, I² = 37%) were significantly different, whereas operating time (MD = 4.00, 95% CI [-17.50 to 25.49], P = .72; P for heterogeneity <.00001, I² = 99%) and complication events (OR = 0.68, 95% CI [0.46 to 1.01], P = .05; P for heterogeneity = .34, I² = 11%) between LPH and OPH were insignificantly different.

CONCLUSION

This study demonstrated that clinical efficacy of OPH was better than that of LPH to some extent, but LPH was a quicker recovery and less harmful therapy.

Percutaneous treatment of hepatocellular carcinoma: State of the art and innovations

Percutaneous treatment of hepatocellular carcinoma (HCC) encompasses a vast range of techniques, including monopolar radiofrequency ablation (RFA), multibipolar RFA, microwave ablation, cryoablation and irreversible electroporation. RFA is considered one of the main curative treatments for HCC of less than 5 cm developing on cirrhotic liver, together with surgical resection and liver transplantation. However, controversies exist concerning the respective roles of ablation and liver resection for HCC of less than 3 to 5 cm on cirrhotic liver. In line with the therapeutic algorithm of early HCC, percutaneous ablation could also be used as a bridge to liver transplantation or in a sequence of upfront percutaneous treatment, followed by transplantation if the patient relapses. Moreover, several innovations in ablation methods may help to efficiently treat early HCC, initially considered as "non-ablatable", and might, in some cases, extend ablation criteria beyond early HCC, enabling treatment of more patients with a curative approach.

Percutaneous cryoablation for hepatocellular carcinoma

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.

Cryoablation Versus Radiofrequency Ablation for Hepatic Malignancies: A Systematic Review and Literature-Based Analysis

The aim of this study is to summarize and quantify the current evidence on the therapeutic efficacy of cryoablation compared with radiofrequency ablation (RFA) in patients with hepatic malignancies in a meta-analysis.Data were collected by searching PubMed, Scopus, and Cochrane databases for reports published up to May 26, 2015. Studies that reported data on comparisons of therapeutic efficacy of cryoablation and RFA were included. The random effects model was used to estimate the pooled relative risks of events comparing cryoablation to RFA for therapy of hepatic malignancies.Seven articles met the inclusion criteria and were included in the meta-analysis. The meta-analysis showed that there was no statistically significant difference in mortality of at least 6 months (odds ratio [OR] = 1.00, 95% confidence interval [CI]: 0.68-1.49) and local tumor progression according to both patients (OR = 1.64, 95% CI: 0.57-4.74) and tumors (OR = 1.81, 95% CI: 0.74-4.38) between cryoablation group and RFA group. However, the risk of complications was significantly higher in the cryoablation group than that in the RFA group (OR = 2.93, 95% CI: 1.15-7.46). When considering the specific complications, only thrombocytopenia (OR = 51.13, 95% CI: 2.92-894.21) and renal impairment (OR = 4.19, 95% CI: 1.34-13.11) but not other complications were significantly higher in the cryoablation group.In conclusion, the 2 methods had almost equal mortality and nonsignificant difference in local tumor progression, with higher risk of complications in cryoablation. Further large-scale, well-designed randomized controlled trials are needed to identify the current findings and investigate the long-term effects of cryoablation compared with RFA for therapy of hepatic malignancies.

Multicenter randomized controlled trial of percutaneous cryoablation versus radiofrequency ablation in hepatocellular carcinoma

Radiofrequency ablation (RFA) is considered a curative treatment option for hepatocellular carcinoma (HCC). Growing data have demonstrated that cryoablation represents a safe and effective alternative therapy for HCC, but no randomized controlled trial (RCT) has been reported to compare cryoablation with RFA in HCC treatment. The present study was a multicenter RCT aimed to compare the outcomes of percutaneous cryoablation with RFA for the treatment of HCC. In all, 360 patients with Child-Pugh class A or B cirrhosis and one or two HCC lesions ≤ 4 cm, treatment-naïve, without metastasis were randomly assigned to cryoablation (n = 180) or RFA (n = 180). The primary endpoints were local tumor progression at 3 years after treatment and safety. Local tumor progression rates at 1, 2, and 3 years were 3%, 7%, and 7% for cryoablation and 9%, 11%, and 11% for RFA, respectively (P = 0.043). For lesions >3 cm in diameter, the local tumor progression rate was significantly lower in the cryoablation group versus the RFA group (7.7% versus 18.2%, P = 0.041). The 1-, 3-, and 5-year overall survival rates were 97%, 67%, and 40% for cryoablation and 97%, 66%, and 38% for RFA, respectively (P = 0.747). The 1-, 3-, and 5-year tumor-free survival rates were 89%, 54%, and 35% in the cryoablation group and 84%, 50%, and 34% in the RFA group, respectively (P = 0.628). Multivariate analyses demonstrated that Child-Pugh class B and distant intrahepatic recurrence were significant negative predictors for overall survival. Major complications occurred in seven patients (3.9%) following cryoablation and in six patients (3.3%) following RFA (P = 0.776).

CONCLUSION

Cryoablation resulted in a significantly lower local tumor progression than RFA, although both cryoablation and RFA were equally safe and effective, with similar 5-year survival rates.

Ablative technologies for hepatocellular, cholangiocarcinoma, and metastatic colorectal cancer of the liver

A wide array of ablation technologies, in addition to the progressive sophistication of imaging technologies and percutaneous, laparoscopic, and open surgical techniques, have allowed us to expand treatment options for patients with liver tumors. In this article, technical considerations of chemical and thermal ablations and their application in hepatic oncology are reviewed.

Advances in clinical application of cryoablation therapy for hepatocellular carcinoma and metastatic liver tumor

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. Although surgical resection and liver transplantation are the curative treatments, many of HCC patients do not qualify for these curative therapies at the presentation. Thus, ablation therapies are currently important modalities in HCC treatment. Among currently available ablation therapies, cryoablation (ie, cryotherapy) is a novel local therapeutic modality. However, cryoablation has not been widely used as one of ablation therapies for HCC, because of historical concerns about risk of bleeding when cryotherapy is delivered by early generation of the argon-helium device. Nevertheless, with technological advances and increased clinical experience in the past decade, clinical application of cryoablation for HCC management has significantly increased. Accumulating data have demonstrated that cryoablation is highly effective in local tumor control with well-acceptable safety profile, and the overall survival is comparable with that of radiofrequency ablation in patients with tumors <5 cm. Compared with radiofrequency ablation and other thermal-based modalities, cryoablation has several advantages, such as the ability to produce larger and precise zones of ablation. This article systemically reviews the advances in clinical application of cryoablation therapy for HCC, including the related mechanisms and technology, clinical indications, efficacy and safety profiles, and future research directions.

Role of surgery and transplantation in the treatment of hepatic metastases from neuroendocrine tumor

Neuroendocrine tumors (NET) are a heterogeneous group of cancers, with indolent behavior. The most common primary origin is the gastro-intestinal tract but can also appear in the lungs, kidneys, adrenals, ovaries and other organs. In general, NET is usually discovered in the metastatic phase (40%-80%). The liver is the most common organ involved when metastases occur (40%-93%), followed by bone (12%-20%) and lung (8%-10%).A number of different therapeutic options are available for the treatment of hepatic metastases including surgical resection, transplantation, ablation, trans-arterial chemoembolization, chemotherapy and somatostatin analogues. Recently, molecular targeted therapies have been used, usually in combination with other treatment options, to improve outcomes in patients with metastases. This article emphasizes on the role of surgery in the treatment of liver metastases from NET.

Role of electrochemotherapy in the treatment of metastatic melanoma and other metastatic and primary skin tumors

Electroporation is a novel therapeutic modality that uses pulsed electrical currents to enhance the uptake of drugs, vaccines and genes into cells, and has been used for over 20 years. Electroporation therapy using cytotoxic drugs is called electrochemotherapy. Electrochemotherapy has been studied in vitro, in vivo and in clinical trials. It is potentially useful for treating patients with metastatic tumors, such as melanoma, and even select primary tumors, such as head and neck squamous cell carcinomas and basal cell carcinoma. Various chemotherapeutic agents have been tested with electroporation therapy, but bleomycin and cisplatin are the two most widely used. The biological basis of electroporation therapy is outlined in this review and basic science studies and the limited clinical studies that have involved electrochemotherapy are reviewed. Particular focus is placed on trials involving melanoma, head and neck cancers and other primary and metastatic skin cancers.

Laparoscopic radiofrequency ablation for the management of colorectal liver metastases: 10-year experience

BACKGROUND

Published results addressing the treatment of colorectal liver metastases (CRLM) with radiofrequency ablation (RFA) vary widely with local recurrence rates of 2-40% and 5-year survival of 14-55%. The goal of this study was to analyze our 10-year experience with laparoscopic RFA.

METHODS

From January 2000 to July 2010, 130 patients underwent laparoscopic RFA for CRLM. Kaplan-Meier analysis was used to assess survival. Univariate and multivariate analysis were performed to identify factors associated with survival and recurrence.

RESULTS

In this cohort, median survival was 40.4 months with 5-year survival of 28.8%. Overall, 9.2% of patients had a local recurrence (3.6% for tumors 3 cm or less). On univariate analysis, factors associated with decreased survival were BMI (P = 0.045), rectal primary (P = 0.005), and increased tumor size (P = 0.002). On multivariate analysis, increased tumor size (HR 1.29 [95% CI: 1.04-1.59]; P = 0.020) and bilobar disease (HR 2.06 [95% CI: 1.02-4.15]; P = 0.044) were associated with decreased survival. On univariate analysis, only BMI was found to be associated with disease recurrence (P = 0.025).

CONCLUSIONS

Our data demonstrate that laparoscopic RFA can achieve a median survival of 40.4 months with a low local recurrence rate. Patients with tumors 3 cm or less have a decreased risk of local recurrence.

Multi-modality treatment of colorectal liver metastases

Liver metastases synchronously or metachronously occur in approximately 50% of colorectal cancer patients. Multimodality comprehensive treatment is the best therapeutic strategy for these patients. However, the optimal pattern of multimodality therapy is still controversial, and it raises several significant concerns. Liver resection is the most important treatment for colorectal liver metastases. The definition of resectability has shifted to focus on the completion of R0 resection and normal liver function maintenance. The role of neoadjuvant and adjuvant chemotherapy still needs to be clarified. The management of either progression or complete remission during neoadjuvant chemotherapy is challenging. The optimal sequencing of surgery and chemotherapy in synchronous colorectal liver metastases patients is still unclear. Conversional chemotherapy, portal vein embolization, two-stage resection, and tumor ablation are effective approaches to improve resectability for initially unresectable patients. Several technical issues and concerns related to these methods need to be further explored. For patients with definitely unresectable liver disease, the necessity of resecting the primary tumor is still debatable, and evaluating and predicting the efficacy of targeted therapy deserve further investigation. This review discusses different patterns and important concerns of multidisciplinary treatment of colorectal liver metastases.

A multimodal approach to the management of neuroendocrine tumour liver metastases

Neuroendocrine tumours (NETs) are often indolent malignancies that commonly present with metastatic disease in the liver. Surgical, locoregional, and systemic treatment modalities are reviewed. A multidisciplinary approach to patient care is suggested to ensure all therapeutic options explored.

American Society of Clinical Oncology 2009 clinical evidence review on radiofrequency ablation of hepatic metastases from colorectal cancer

PURPOSE

To review the evidence about the efficacy and utility of radiofrequency ablation (RFA) for hepatic metastases from colorectal cancer (CRHM).

METHODS

The American Society of Clinical Oncology (ASCO) convened a panel to conduct and analyze a comprehensive systematic review of the RFA literature from Medline and the Cochrane Collaboration Library.

RESULTS

Because data were considered insufficient to form the basis of a practice guideline, ASCO has instead published a clinical evidence review. The evidence is from single-arm, retrospective, and prospective trials. No randomized controlled trials have been included. The following three clinical issues were considered by the panel: the efficacy of surgical hepatic resection versus RFA for resectable tumors; the utility of RFA for unresectable tumors; and RFA approaches (open, laparoscopic, or percutaneous). Evidence suggests that hepatic resection improves overall survival (OS), particularly for patients with resectable tumors without extrahepatic disease. Careful patient and tumor selection is discussed at length in the literature. RFA investigators report a wide variability in the 5-year survival rate (14% to 55%) and local tumor recurrence rate (3.6% to 60%). The reported mortality rate was low (0% to 2%), and the major complications rate was commonly reported to be between 6% and 9%. RFA is currently performed with all three approaches.

CONCLUSION

There is a compelling need for more research to determine the efficacy and utility of RFA to increase local recurrence-free, progression-free, and disease-free survival as well as OS for patients with CRHM. Clinical trials have established that hepatic resection can improve OS for patients with resectable CRHM.

Open surgical is superior to percutaneous access for radiofrequency ablation of hepatic metastases

PURPOSE

This study was designed to determine the best approach to radiofrequency ablation (RFA) in the liver.

METHODS

From a total of 41 procedures, 37 patients with 47 tumors were treated with RFA for metastatic disease. Indications included colorectal cancer (n=28, 68%), neuroendocrine tumors (n=2, 5%), gynecological primaries (n=4, 10%), pancreatic/duodenal cancer (n=2, 5%), and miscellaneous entities (n=5, 12%). Mean follow-up period was 18 (median, 18) months. All ways of approach to RFA were applied: percutaneous was chosen in 17 (41.5%), laparoscopic and hand-assisted laparoscopic in 5 (12.2%), and open surgical in 19 cases (46.3%), and in 10 cases, RFA was combined with hepatic resection. The average maximum tumor size was 2.3 (range, 0.8-6) cm, and the mean number of nodules treated per patient in a single session was 1.3 (range, 1-3).

RESULTS

Overall survival was 59.5% at 2 years, recurrence-free 2-year survival was 12.6%, local tumor recurrence rate was 34%, and overall recurrence was 75.6%. Local tumor recurrence and disease-free survival were significantly improved in the open surgically treated patients compared with the percutaneous treatment group (15.8% [n=3] vs. 58.8% [n=10] and 11.5 vs. 7.9 months, p<0.01 [chi2 test] and p<0.05 [log-rank test], respectively).

CONCLUSIONS

Open surgical approach is superior to percutaneous access for RFA in metastatic hepatic disease.

A family of new instruments for laparoscopic radiofrequency ablation of malignant liver lesions

Primary and secondary liver tumors may be treated with radiofrequency ablation (RFA) to improve tumor control and to increase patient survival. Lesions are punctured percutaneously or during open surgery. However, not all of the lesions are accessible percutaneously due to their localization: Adjacent structures could be endangered and/or the treatment would cause severe pain. Open surgery is an option in these cases but significantly more invasive. Laparoscopic RFA (LRFA) is an additional possibility in those cases: It offers a better access to difficult lesions than via the percutaneous route and is also less invasive than open surgery. The precision of targeting, however, in LRFA still has to be improved. In an in-vivo feasibility study we used a tumor mimic model in pigs to examine the applicability of laparoscopic RFA in combination with laparoscopic ultrasound using a set of dedicated new instruments to handle the RFA probe. To increase the ablation volume, the liver blood flow was reduced performing a Pringle maneuver. It is demonstrated that this set of specially designed instruments is indeed applicable and facilitates the targeting of liver lesions of any localization. Accordingly, it could significantly enlarge the applicability of LRFA.

Laser ablation of hepatocellular carcinoma-A review

A wide range of local thermal ablative therapies have been developed in the treatment of non resectable hepatocellular carcinoma (HCC) in the last decade. Laser ablation (LA) and radiofrequency ablation (RFA) are the two most widely used of these. This article provides an up to date overview of the role of laser ablation in the local treatment of HCC. General principles, technique, image guidance and patient selection are discussed. A review of published data on treatment efficacy, long term outcome and complication rates of laser ablation is included and comparison with RFA made. The role of laser ablation in combination with transcatheter arterial chemoembolization is also discussed.

Neuroendocrine tumors: role of interventional radiology in therapy

The management of neuroendocrine tumors (NETs) is complex. Although NETs can affect a variety of organ systems, hepatic metastatic disease in particular lends itself to a wide range of interventional treatment options. Prior detailed radiologic assessment and careful patient selection are required. Curative surgery should always be considered but is rarely possible. Embolization, radionuclide therapy, or ablative techniques may then be undertaken. Transcatheter arterial embolization (TAE) may be used alone or in combination with transcatheter arterial chemoembolization (TACE). NET type and extent of hepatic involvement are factors that can help predict the success of either TAE or TACE. Embolization techniques can also be useful in patients with nonhepatic NETs. Radionuclide therapy is emerging as a valuable adjunct and is dependent on positive somatostatin receptor status. Therapeutic radiopeptides may be delivered arterially. Ablative techniques have been shown to play a role in the palliation of symptoms and principally involve radiofrequency ablation. Hepatic cryotherapy and percutaneous ethanol injection have also been used. A multidisciplinary approach to treatment and follow-up is important. Imaging should involve dual-phase multidetector computed tomography and contrast material-enhanced magnetic resonance imaging. The role of the interventional radiologist will continue to expand as imaging techniques become more refined.

Image-guided radiofrequency ablation (RFA) of spinal tumors

PURPOSE

To evaluate retrospectively the efficacy and safety of radiofrequency ablation (RFA) in patients with spinal tumors.

MATERIALS AND METHODS

Forty-one patients (25 men, 16 women; age range, 46-82 years) with nonresectable primary or secondary tumor involvement of the spine unresponsive to chemo- and radiotherapy received RFA treatment. Two radiofrequency ablation systems, one with a cool-tip electrode and one with an expandable electrode catheter, were used. Both systems work impedance controlled with a power output of 150- 200 W. Each coagulation cycle lasted 12-15 min depending on tumor impedance. Several single RFA cycles of 15 min each were used for overlapping RFAs in tumors with diameters of more than 3 cm. Temperature was kept between 50 degrees C and 120 degrees C and was chosen according to spinal cord distance and patient heat tolerance during the ablation. Multi-slice computed tomography (CT) combined with C-arm fluoroscopy guided the intervention. Efficacy outcomes were assessed after about 6 weeks, 6 months, and more than 6 months using standardized questionnaires and indices regarding tumor pain, pain disability, functional activities, quality of life, neurological status, and tumor progression.

RESULTS

RFA significantly reduced tumor-induced pain within 6 weeks, improved daily activities, and maintained quality of life. Mean time to tumor progression was 730+/-54 days (Kaplan-Meier estimate). No RFA-associated complications were reported.

CONCLUSION

RFA of primary and secondary spinal tumors, which were unresponsive to chemo- and radiotherapy and prone to progression, is a safe, resource-saving, and highly effective percutaneous technique in patients with nonresectable spinal tumors.

Cryosurgery for hepatocellular carcinoma

Cryosurgery is an important treatment modality for unresectable hepatocellular carcinoma (HCC). There are different forms of cryosurgery for HCC including intraoperative cryoablation with or without excision, laparoscopic liver cryosurgery, percutaneous liver cryoablation under the guidance of ultrasonography, CT or MRI. Cryoablation, as a local therapy for HCC, has certain advantages over other forms of treatment. It is able to destroy only tumor tissue in the liver while sparing more noninvolved tissues. Tumors close to the vessel systems can safely undergo cryoablation due to the warming effect of circulating blood in large blood vessels. Liver cryoablation is more effective than surgical resection for multiple liver tumors. Cryosurgery in combination with transarterial chemoembolization (TACE), alcohol injection or ¹²⁵iodine seed implantation has a complementary efficacy. Clinically, cryosurgery for HCC is performed according to the following principles. Intraoperative or percutaneous cryosurgery may be performed for liver tumors < 5 cm or ≤3 cm, TACE for liver tumors > 5 cm followed by percutaneous cryosurgery. Liver tumors > 5 cm with an irregular margin, may also undergo intraoperative or percutaneous cryosurgery followed by alcohol injection or ¹²⁵iodine seed implantation in the margins of tumors.

Radiofrequency ablation for hepatocellular carcinoma and metastatic liver tumors: a comparative study

BACKGROUND

This study compared the effectiveness of radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) and liver metastases.

METHODS

We compared the outcomes of 240 patients with HCC and 44 patients with liver metastases treated with RFA. Data were prospectively collected and retrospectively analyzed. Effects of different variables on recurrences were studied.

RESULTS

A total of 406 tumor nodules were treated. The median size of the largest ablated tumor was 2.5 cm, and the median tumor number was 1. Complete tumor ablation was achieved in 91.2%. Local recurrence rate was 15.4% after a median follow-up of 24.5 months. There was no significant impact of tumor pathology on local recurrence. However, patients with liver metastasis had higher extrahepatic recurrence rate (P = 0.019) and shorter disease-free survival (P = 0.007). Patients with multiple tumors had higher local (P = 0.047) and extrahepatic (P = 0.019) recurrence rates than those with a solitary tumor. Tumor size had an impact on local recurrence rate only in patients with liver metastasis with a higher rate in those with tumor > 2.5 cm in diameter (P = 0.028).

CONCLUSIONS

Tumor pathology does not appear to have a significant impact on local recurrence rates. RFA is effective in local tumor control for both HCC and liver metastasis.

Update on the management of neuroendocrine hepatic metastases

Neuroendocrine tumors (NETs) are rare and represent a diverse collection of malignancies that occur in many organ systems throughout the body, including the gastrointestinal and respiratory tracts. Unfortunately, the majority of patients with NETs have hepatic metastases at the time of diagnosis. Although some patients may be asymptomatic, others have unusual clinical presentations and variable tumor growth patterns. Although many patients have long indolent courses, without treatment, most patients die within 5 years of diagnosis. This article reviews the care of patients with NETs and hepatic metastases, with emphasis on the increasingly important role of oncologic image-guided interventions.

Cryoablation of liver tumours -- a review of mechanisms, techniques and clinical outcome

Several techniques exist for in situ destruction or ablation of liver tumours not eligible for resection. Cryoablation, i.e. the use of low temperatures to induce local tissue necrosis, was among the first of the thermal ablative techniques widely used. The procedures have typically been performed by surgeons during laparotomy, but recently minimally invasive cryoablation has been reported feasible. The present review focuses on mechanisms of tissue destruction, techniques of ablation including procedural monitoring, and clinical outcome following cryoablation of liver tumours. Plausible causes of tumour persistence at the site of ablation, i.e. local treatment failure, are discussed. Shortcomings exist in monitoring of the freezing process and may be a main cause. The evidence for the long-term outcome following liver tumour cryoablation needs to be improved. Cryoablation has been challenged by other techniques of tumour ablation such as radiofrequency ablation. Randomised trials against these modern techniques may define the role of cryoablation in the treatment of liver tumours. With improved imaging technology and patient selection, cryoablation of liver tumours may hold promise for selected patients.

Transpleurodiaphragmatic cryosurgical ablation for recurrent unresectable colorectal liver metastases

BACKGROUND AND OBJECTIVES

Cryosurgical ablation (CSA) allows the focal destruction of unresectable liver metastases after previous liver resection. The abdominal approach may be difficult for recurrent colorectal cancer metastases located in the upper part of the remaining liver, close to the inferior vena cava (IVC), the hepatic veins, and the diaphragm. A transpleurodiaphragmatic access was assessed for safety and efficacy.

METHODS

Between September 1999 and July 2004, 13 patients with recurrent unresectable colorectal liver metastases underwent transpleurodiaphragmatic CSA via limited right thoracotomy. Seventeen lesions were treated; median diameter was 31 mm (range 13-40 mm). One to three cryoprobes were used, depending on the size and location of metastases.

RESULTS

There was no operative death; three patients developed minor complications (23%). Median hospital stay was 10 days (8-14 days). After a median follow-up of 26 months (range 8-69 months), 9 patients were alive, and 5 were disease-free. Six patients had liver recurrences outside the cryolesion. Median disease free survival was 12 months with 60% 3-year survival after CSA and 58% 5-year survival after first liver surgery.

CONCLUSIONS

Transpleurodiaphragmatic CSA is safe and effective in selected patients with unresectable recurrent liver metastases from colorectal cancer.

Bipolar radiofrequency ablation of liver metastases during laparotomy. First clinical experiences with a new multipolar ablation concept

BACKGROUND AND OBJECTIVE

Radiofrequency ablation (RFA) is a promising method for local treatment of liver malignancies. Currently available systems for radiofrequency ablation use monopolar current, which carries the risk of uncontrolled electrical current paths, collateral damages and limited effectiveness. To overcome this problem, we used a newly developed internally cooled bipolar application system in patients with irresectable liver metastases undergoing laparotomy. The aim of this study was to clinically evaluate the safety, feasibility and effectiveness of this new system with a novel multipolar application concept.

PATIENTS AND METHODS

Patients with a maximum of five liver metastases having a maximum diameter of 5 cm underwent laparotomy and abdominal exploration to control resectability. In cases of irresectability, RFA with the newly developed bipolar application system was performed. Treatment was carried out under ultrasound guidance. Depending on tumour size, shape and location, up to three applicators were simultaneously inserted in or closely around the tumour, never exceeding a maximum probe distance of 3 cm. In the multipolar ablation concept, the current runs alternating between all possible pairs of consecutively activated electrodes with up to 15 possible electrode combinations. Post-operative follow-up was evaluated by CT or MRI controls 24-48 h after RFA and every 3 months.

RESULTS

In a total of six patients (four male, two female; 61-68 years), ten metastases (1.0-5.5 cm) were treated with a total of 14 RF applications. In four metastases three probes were used, and in another four and two metastases, two and one probes were used, respectively. During a mean ablation time of 18.8 min (10-31), a mean energy of 48.8 kJ (12-116) for each metastases was applied. No procedure-related complications occurred. The patients were released from the hospital between 7 and 12 days post-intervention (median 9 days). The post-interventional control showed complete tumour ablation in all cases.

CONCLUSIONS

Bipolar radiofrequency using the novel multipolar ablation concept permits a safe and effective therapy for the induction of large volumes of coagulation in the local treatment of liver metastases.

Laparoscopic surgery: current status, issues and future developments

Laparoscopic surgery has come a long way since its introduction two decades ago. In essence it represents a new era of technology-dependent surgical interventions, and to some extent its future progress depends on the growth of interventional technologies and devices (facilitative, enabling and additive). Laparoscopic surgery has had a significant impact on all surgical disciplines and is now firmly embedded in routine surgical practice. There remain, however, several outstanding issues that need to be addressed. These concern mainly quality assurance, training, resource allocation, assessment of competence and tiers of laparoscopic surgical practice in line with the changing situation facing the next generation of surgeons.

Chemoembolization and other ablative therapies for liver metastases of gastrointestinal endocrine tumours

Hepatic metastases are frequent in patients with gastroentero-pancreatic (GEP) endocrine tumours; their presence significantly influences overall prognosis. Surgery, although the treatment of choice for hepatic metastases, is frequently impossible due to disease extent. Systemic chemotherapy in patients with diffuse and/or progressive liver metastases yields disappointing results especially in patients with metastases from midgut origin. In addition, in patients with carcinoid syndrome, the efficacy of somatostatin analogues wanes due to disease progression and development of tachyphylaxis. Locoregional strategies with vascular occlusion inducing ischemia in these highly vascular GEP tumours are indeed other options and may be performed using either surgical or radiological techniques (e.g. surgical ligation of the hepatic artery, transient hepatic ischemia, or sequential hepatic arterialization). Trans-catheter arterial chemoembolization is efficacious in both the control of hormonal symptoms and yields reliable objective tumour responses. Treatments aimed at regional destruction either alone or in combination with surgery include radiofrequency ablation and cryotherapy and may also be considered in certain circumstances.

Outcome of regional and local ablative therapies for hepatocellular carcinoma: a collective review

BACKGROUND

Transcatheter arterial (chemo) embolization (TACE), cryoablation (CA) and percutaneous ethanol injection (PEI) were the first regional and local ablative techniques that came into use for irresectable HCC. Radiofrequency ablation (RFA) and interstitial laser coagulation (ILC) followed and have now evolved rapidly. It would not be ethical to compare resection with ablation in patients well enough to undergo major surgery. Therefore, hepatic resection and hepatic transplantation remain the only curative treatment options for HCC.

METHODS

On the basis of a Medline literature search and the authors' experiences, the principles, current status and prospects of TACE and local ablative techniques in HCC are reviewed.

RESULTS

Complete tumour necrosis can be achieved in 60-100% of patients treated with PEI (70-100%), cryoablation (60-85%), RFA (80-90%) or ILC (70-97%). After TACE significant tumour response is achieved in 17-61.9% but complete tumour response is rare (0-4.8%) as viable tumour cells remain after TACE. Five-year survival rates are available for TACE (1-8%), PEI (0-70%) and cryoablation (40%). Only PEI and RFA were compared in one RCT. RFA was associated with fewer treatment sessions and a higher complete necrosis rate. Furthermore, all techniques are associated with low morbidity and mortality, but cryoablation seems to be associated with a higher morbidity rate.

CONCLUSION

TACE has shown to be a valuable therapy with survival benefits in strictly selected patients with unresectable HCC. RFA and PEI are now considered as the local ablative techniques of choice for the treatment of, preferably small, HCC. When tumours are located close to bile ducts or large vessels, PEI remains a valuable therapy. Completeness of ablation can be more easily monitored during cryoablation and another advantage of cryoablation is the possibility of edge freezing. The results of ILC are comparable to RFA with only few side effects and high tumour response rates.

Long-term Survival of Patients with Unresectable Colorectal Liver Metastases treated by Percutaneous Interstitial Laser Thermotherapy

In situ ablation of colorectal cancer (CRC) liver metastases is an accepted form of treatment for selected patients. It is associated with low morbidity and mortality and increases the number of patients who may benefit from therapy compared to resection alone. This study assesses the impact of interstitial laser thermotherapy (ILT) on local tumor control and long-term survival in patients with unresectable CRC liver metastases. Percutaneous ILT was performed in patients with unresectable CRC liver metastases between January 1992 and December 1999 using a bare-tip quartz fiber connected to an Nd:YAG laser source. This was prior to the routine use of a diffusing fiber for ablative therapy. Treatment was monitored with real-time ultrasonography. Tumors were considered unresectable based on their anatomic location or the extent of liver involvement. Patients with extrahepatic disease, more than five liver metastases, or tumors larger than 10 cm in diameter were excluded from this study. Local tumor control was assessed by dynamic computed tomography (CT) 6 months after therapy. Long-term follow-up was undertaken, and the impact of various factors on survival was analyzed. Eighty patients with a mean age of 63.8 years were suitable for ILT. In total, 168 liver tumors with a median diameter of 5 cm (range 1-10 cm) were so treated. There were no procedure-related deaths. The overall complication rate was 16%, with all cases managed conservatively. Bradycardia (n = 5), pneumothorax (n = 3), and persistent pyrexia (n = 3) were the most common complications. Complete tumor ablation was noted in 67% of patients assessed by CT 6 months following the initial therapy. Median follow-up was 35 months (range 4-96 months), with 10 patients alive at the end of this period. Altogether there were 67 deaths, which were related to hepatic disease in 55 cases and to extrahepatic disease in 9; they were unrelated to malignancy in 3 others. Three patients were excluded from follow-up after ILT down-staging of tumors that allowed complete surgical resection. The median disease-free survival of patients treated by ILT was 24.6 months, with a 5-year survival of 3.8%. Poor tumor differentiation and the presence of more than two hepatic metastases were associated with lower overall survival (p < 0.01). Fourteen patients treated by ILT for postoperative hepatic recurrences had the best outcome, with a median overall survival of 36.3 months and a 5-year survival of 17.2%. Percutaneous ILT is a minimally invasive, safe, effective technique that appears to improve overall survival in specific patients with unresectable CRC liver metastases, compared to the natural history of untreated disease reported in the literature.

Radiofrequency ablation of cancer

Radiofrequency ablation (RFA) has been used for over 18 years for treatment of nerve-related chronic pain and cardiac arrhythmias. In the last 10 years, technical developments have increased ablation volumes in a controllable, versatile, and relatively inexpensive manner. The host of clinical applications for RFA have similarly expanded. Current RFA equipment, techniques, applications, results, complications, and research avenues for local tumor ablation are summarized.

Percutaneous ablation of liver tumours

The goal of local ablation treatment of hepatic disease is to prolong survival for patients with unresectable tumours. Presently, influence on survival is difficult to estimate because of the heterogeneity of indications and treatments and short follow-up. This chapter therefore focuses on potential benefits and limitations, complications and solutions for improvement. The main problems with in situ ablation are the lack of good imaging techniques to determine the extent of disease and the lack of a method for real-time monitoring of irreversible tissue effect. With one exception, there are no prospective, randomized studies comparing local destruction methods. It appears that percutaneous ethanol injection and cryotherapy should be replaced by radiofrequency ablation (RFA) or interstitial laser thermotherapy (ILT) and that there is little difference in outcome between RFA and ILT. Intraoperative RFA or ILT is valuable as an adjunct to hepatic resection in order to increase the rate of resectability. The percutaneous approach needs further development. It might be valuable in a few truly unresectable or inoperable patients or in selected patients with neuroendocrine liver metastases. In the large majority of unresectable patients it should, however, presently be used and evaluated only in prospective, randomized studies.

Ablative therapies for liver metastases of gastroenteropancreatic endocrine tumors

Hepatic metastases are frequent in patients with gastroenteropancreatic (GEP) endocrine tumors. The presence of hepatic metastases affects overall prognosis and quality of life especially in the presence of debilitating functional syndromes. Surgery, although the method of choice for hepatic metastases, is usually impossible due to disease extent. Results of systemic chemotherapy are also disappointing especially in patients with metastases from midgut GEP tumors. These latter patients usually have carcinoid syndrome which can be controlled by somatostatin analogues. Other therapeutic options in the treatment of highly vascular liver metastases from GEP tumors are locoregional strategies by inducing vascular occlusion resulting in ischemia and necrosis of tumoral tissue. Surgical ligation of the hepatic artery or transient hepatic ischemia has been replaced by transcatheter arterial chemoembolization (TACE). TACE has proven effective in controlling symptoms and gives objective tumor response in about half of patients. Other regional destructive methods, used either alone or in combination with surgery, include radiofrequency ablation and cryotherapy. The latter strategies are poorly evaluated to date and are usually adjuncts to surgery and reserved for limited disease.

Laparoscopic liver resections for hepatocellular carcinoma (HCC) in cirrhotic patients

BACKGROUND

The laparoscopic approach for liver resections is still limited and controversial. Nevertheless the advantages connected with a mini-invasive approach are significant, especially in cirrhotic patients. In recent years the progress of laparoscopic procedures and the development of new and dedicated technologies have made endoscopic hepatic surgery feasible and safe. The aim of this study was to report the results of our experience in laparoscopic liver surgery for hepatocellular carcinoma (HCC) in cirrhotic patients.

METHODS

From 2000 to 2003, 16 patients (10 male, 6 female; age 48-69 years; mean age 60.1 years) with HCC and associated severe but well compensated liver cirrhosis underwent laparoscopic hepatic resections at our department. Mean tumour size was 2.9 cm (range 1-3.9). Seven of these lesions were in the left liver and nine in the right lobe. Laparoscopy was performed under CO(2) pneumoperitoneum. The liver was always examined using laparoscopic ultrasound (US) to confirm the extension of the lesions and their relationships to the vasculature. The Pringle manoeuvre was not used. The transection of liver parenchyma was obtained by the use of a harmonic scalpel. The specimens were placed in a plastic bag and removed without contact to the abdominal wall.

RESULTS

There was one conversion to laparotomy for inadequate exposure. In the remaining 15 patients we performed 13 non-anatomical resections, I segmentectomy and I anatomical left lobectomy. The mean operative time was 152 min (range 80-180). Mean blood loss was 280 ml and none of the patients required blood transfusions. In two patients the resection margin was <1 cm but the capsule was not infiltrated at histology. One patient died on the third postoperative day from a severe respiratory distress syndrome. Major morbidities occurred in two patients who developed moderate postoperative ascites, which resolved successfully with conservative treatment. The mean postoperative hospital stay was 8.8 days. Mean follow-up time has been 18 months, and to date no recurrences at the site of resection or port-site metastases have been observed.

DISCUSSION

Limited laparoscopic liver resections in cirrhotic patients are technically feasible with a low complication rate when careful selection criteria are followed (hepatic involvement limited and located in the left or anterior right segments, tumour size smaller than 5 cm, Child-Pugh class A). This approach could be considered the best option for the treatment of small esophitic or subcapsular HCC on well compensated cirrhosis and a useful option when it is necessary to perform a left lateral anatomical resection or non-anatomical resection in well selected patients. In fact the mini-invasive approach can minimise the postoperative morbidity rate, which is still too high in this group of patients. It must be performed in highly specialised units by surgeons assisted by all requested technologies and with extensive experience in hepatobiliary and advanced laparoscopic surgery.