Hepatic cryosurgery for liver metastases. Long-term follow-up

Perioperative outcomes and long-term survival of cryosurgery on unresectable pancreatic cancer: a systematic review and meta-analysis

BACKGROUND

Pancreatic cancer (PC) continues to rank as one of the deadliest forms of cancer, with the majority of patients being diagnosed with unresectable disease. The implementation of cryoablation-based comprehensive treatment is expected to lead to a reduction in tumour size and potentially achieve complete resection. However, the availability of systematic and evidence-based treatment guidelines for cryoablation in pancreatic cancer is currently limited.

MATERIALS AND METHODS

A computerized search was conducted in the Medline, Embase, Cochrane Library databases, and Clinicaltrials to retrieve studies published from August 1987 to June 2023. The perioperative outcomes and long-term survival of patients with locally advanced pancreatic cancer (LAPC) or metastatic pancreatic cancer (mPC) who underwent cryosurgery were systematically collected. Heterogeneity was assessed using Cochran's Q test, and a funnel plot was implemented to evaluate publication bias. Data were pooled and analyzed using Stata 14.0 software. The Newcastle-Ottawa Quality Assessment Form tool was employed for quality evaluation.

RESULTS

Nine studies, including 368 patients, were identified. The pooled overall incidence rate was 4% (95% CI: 0-14%; I²=54.06%) for acute pancreatitis, 0% (95% CI: 0-0%; I²=0.0%) for delayed gastric emptying, 0% (95% CI: 0-1%; I²=0.0%) for postoperative pancreatic fistula (POPF) or bile leakage, 2% (95% CI: 0-5%; I²=0.0%) for bleeding, and 4% (95% CI: 0-12%; I²=70.46%) for fever. The subgroup analysis revealed that the percutaneous treatment group had a lower incidence of complications compared to laparotomy but had higher incidences of POPF, bleeding, and pancreatitis than the intraoperative group. Median overall survival (OS) varied from 5 to 16.2 months. The median survival rates at 6, 12, 24, and 36 months for patients who underwent cryosurgery were as follows: 94.9%, 64.8% (range: 4.8-63.1%), 22.80%, and 9.5%, respectively.

CONCLUSION

With the advancements in cryoablation and anti-tumour therapy, cryoablation has emerged as a promising treatment modality for patients with unresectable pancreatic cancer. According to existing literature, the combination of cryoablation with radioactive particle implantation or immunotherapy has demonstrated considerable efficacy and safety. However, while the majority of included data is derived from retrospective studies, it is imperative to conduct larger sample sizes or prospective trials for further validation.

Ablative Therapy in Non-HCC Liver Malignancy

Surgical extirpation of liver tumors remains a proven approach in the management of metastatic tumors to the liver, particularly those of colorectal origin. Ablative, non-resective therapies are an increasingly attractive primary therapy for liver tumors as they are generally better tolerated and result in far less morbidity and mortality. Ablative therapies preserve greater normal liver parenchyma allowing better post-treatment liver function and are particularly appropriate for treating subsequent liver-specific tumor recurrence. This article reviews the current status of ablative therapies for non-hepatocellular liver tumors with a discussion of many of the clinically available approaches.

Yttrium-90 Selective Internal Radiation Therapy Plus Cryoablation for Recurrent Adrenocortical Carcinoma With Liver Metastases

Advanced adrenocortical carcinoma (ACC) has a poor prognosis and is often resistant to the conventional regimens of mitotane administration and systemic chemotherapy. In addition to surgery, local therapeutic measures can be valuable. Here, we present the case of a 33-year-old woman who developed left retroperitoneal local recurrent ACC with hepatic and pulmonary metastases 1 year after radical adrenalectomy. The tumors progressed under chemotherapy and mitotane treatments. She was treated with yttrium-90 selective internal radiation therapy (⁹⁰Y SIRT) for hepatic metastases and cryoablation of the local recurrent tumor, after which significant tumor shrinkage was observed. She then received radiofrequency ablation for the residual hepatic metastases and radiotherapy to the residual local recurrent tumor. Complete remission was achieved and maintained at least until the data cutoff day (15.8 months after the last treatment). This is the first published report of cryoablation in a patient with ACC and the third report of ⁹⁰Y SIRT use for hepatic metastasis of ACC. Cryoablation and ⁹⁰Y SIRT are local treatment choices for ACC that are worthy of further study.

Local Treatments in the Unresectable Patient with Colorectal Cancer Metastasis: A Review from the Point of View of the Medical Oncologist

For patients with isolated liver metastases from colorectal cancer who are not candidates for potentially curative resections, non-surgical local treatments may be useful. Non-surgical local treatments are classified according to how the treatment is administered. Local treatments are applied directly on hepatic parenchyma, such as radiofrequency, microwave hyperthermia and cryotherapy. Locoregional therapies are delivered through the hepatic artery, such as chemoinfusion, chemoembolization or selective internal radiation with Yttrium 90 radioembolization. The purpose of this review is to describe the different interventional therapies that are available for these patients in routine clinical practice, the most important clinical trials that have tried to demonstrate the effectiveness of each therapy and recommendations from principal medical oncologic societies.

Mature Experiences Using Local Therapy for Oligometastases

Cancer is a heterogeneous disease, consisting of a spectrum of disorders ranging from local-only disease to those that are widely metastatic from their onset. The oligometastatic state, in which tumors harbor a limited number of metastases, may be curable in a subset of patients. The early success of surgical resection of hepatic metastases from colorectal cancer led to investigations into metastatectomy of other sites and, more recently, into the use of stereotactic ablative radiotherapy (SABR) for oligometastatic disease. This article reviews the data establishing the role of surgery for managing limited metastatic disease. Further, we review recent experiences using alternative local therapies, such as SABR, for oligometastases. This review also discusses ongoing trials evaluating local therapies for patients with a limited burden of metastatic cancer.

Cryoimmunology: Opportunities and challenges in biomedical science and practice

Autologous and allogeneic cryoimmunological medicine is a brand new branch of biomedical science and clinical practice that examines the features and formation of the immune response to immunogenic properties of normal and malignant biological structures altered by ultralow temperature, as well as specific changes in the structural and functional characteristics of immune cells and tissues after cryopreservation. Cryogenic protein denaturation phenomenon provides important insights into the mechanisms underlying the damage to cryogenic lesions immediately after freeze-thawing sessions in bioscience and medicine applications. The newly formed cryocoagulated protein components (cryomodified protein components) are crucial in cryoimmunology from the perspective of the formation of immunological substances at ultralow temperatures. Dendritic cells and cryocell detritus (cryocell debris) formed in living biological tissue after exposure to ultralow temperature in vivo may be an indication of one of the essential mechanisms involved in the cryoimmunological response of living structures to the impact of ultralow temperature exposure. Hence, the formation of new autologous and allogeneic cryoinduced immunogenic substances is a novel concept in biomedical research globally. Accordingly, this review focuses on issues concerning the peculiarities of the interaction of the immune system with a dominant malignant neoplasm tissue after exposure to subzero temperatures, considering the original cryogenic technical approaches. We present an overview of the state-of-the-art methods of cryoimmunology, and their major developments, past and present. The need for the delineation of structural and functional characteristics of the biological substrates of the immune system after cryopreservation that can be used in adoptive cell therapy, especially in cancer patients, is emphasized.

Estimation of the stable frozen zone volume and the extent of contrast for a therapeutic substance

Background

In biomedical science and clinical practice, an estimation of the stable frozen zone volume and distribution of concentration fields of injected diagnostic and healing solutions in the tissues of living organisms is of great importance and does not currently have any mathematical solution aimed at its precise evaluation.

Objective

The aim of this research is the estimation of the stable frozen zone volume at ultra-low temperatures as well as the distribution of temperature areas and concentration fields of injected diagnostic and healing substances in vitro. The results can improve our understanding of the stable frozen zone volume and the extent of contrast for a therapeutic substance.

Materials and methods

A cryogenic zone (ice ball) was generated at -180°C using liquid nitrogen without any difficulties in vitro. The effects of freeze-thaw processes using ultra-low temperature and the cryogenic response of a 1.5% gelatin solution in water (%g/v) kept at a constant temperature of 20°C and continuously stirred were mathematically analyzed. The stable frozen zone volume was illustrated in vitro and measured in terms of its length, depth and cryogenic margin using a standard medical ruler and Vernier caliper after a freezing period at -180°C, using liquid nitrogen to provide cooling and freezing of a small portion of this solution in the vessel at room temperature (20°C). Round-shaped cryoprobes with diameters of 15 mm and 50 mm were applied to create a frozen zone volume in vitro. A single cryoprobe was used per procedure. The sample exposure time was 3 min. After this time, the volume of the frozen region remains unchanged, which indicates that the equilibrium stationary state has been reached. The experimental design, cryogenic procedure and freeze-thaw processes of the hemisphere were described and illustrated in vitro item by item. The statistical analysis manifested significant differences that were found between the 50 mm and 15 mm cryoprobes with regards to the freezing diameter, depth, and cryogenic margin (P < 0.001).

Results

An illustrated analytical mathematical solution of equations determined the stable frozen zone volume and the radius of the sphere of the frozen medium in the equilibrium stationary state. The resulting assessment provided the basis for the creation of mini- and micro-cryoprobes as well as cryoneedles for local tissue freezing in living biological structures. A solution to the equations was obtained under the boundary conditions with a set stable temperature value on the boundary surface of the cryoprobe as well as at the surface well-away from it, where the temperature is equal to the stable temperature of the environment. For example, this solution gives that in the case of a hemispherical cryoprobe radius of 1 mm, the frozen zone volume was more than three orders of magnitude greater than the volume of the cryoprobe itself and was equal to approximately 4 cm³. The determination of the fractal dimension can consider the individual characteristics of the spread of the contrast medium or therapeutic substance(s) in living tissue. Based on fractal theory, our innovative mathematical formulas allow for the assessment of the effective distribution of contrast medium in living biological structures, specifically for tissues assessed for diagnostic purposes, and they enable the selection of an optimal treatment strategy in medical practice.

Conclusion

A simple mathematical approach to solving the problems of assessing the stable frozen zone volume and distribution of temperature areas and concentration fields of injected diagnostic and healing substances in living biological structures, particularly living tissue in vitro, is presented in this study. The expressed quantitative mathematical formulas determine the stable stationary frozen zone volume and provide the basis for the creation of mini- and micro-cryoprobes. The application of fractal theory is proposed for assessing the distribution efficiency of contrast medium and therapeutic substance(s) in living biological structures for diagnostic purposes and for selecting a compassionate treatment strategy in medical professional practice.

Role of thermal ablation in the management of colorectal liver metastasis

With a recent randomized prospective trial revealing that thermal ablative therapy as local tumor control improved overall survival (OS) in patients with unresectable colorectal cancer liver metastases (CRLM), thermal ablation continues to remain as an important treatment option in this patient population. Our aim of this article is to review the current role of the ablative therapy in the management of CRLM patients. Main indications for thermal ablation include (I) unresectable liver lesions; (II) in combination with hepatectomy; (III) in patients with significant medical comorbidities or poor performance status (PS); (IV) a small (<3 cm) solitary lesion, which would otherwise necessitate a major liver resection; and (V) patient preference. There are several approaches and modalities for ablative therapy, including open, percutaneous, and laparoscopic approaches, as well as radiofrequency ablation (RFA) and microwave ablation (MWA). Each approach and ablation modality have its own pros and cons. Percutaneous and laparoscopic approaches are preferred due to minimally invasive nature, yet laparoscopic approach has more benefits from thorough intraoperative ultrasound (US) exam as well as complete peritoneal staging with laparoscopy. Similarly, whereas high local tumor failure rate has been a major concern with RFA, MWA or microwave thermosphere ablation (MTA) have demonstrated significantly improved local tumor control due to homogenous tissue heating, ability to reach higher tissue temperatures, and less susceptible to the "heat-sink" effect. Although liver resection is the standard of care for CRLM, there have been some retrospective studies demonstrating similar oncological outcome between ablative therapy and surgical resection in very selected populations with small (<3 cm) solitary CRLM. Lastly, ablative therapy and liver resection should not be mutually exclusive, especially in the management of bilobar liver metastases. Concomitant ablative therapy with hepatectomy may spare the patients from having two-stage hepatectomy with less morbidity. The role of the thermal ablation will continue to evolve in patients with resectable and ablatable lesions owing to newly emerging technology, in addition to new systemic treatment options, including immunotherapy for metastatic colorectal cancer (CRC).

Cryotherapy for liver metastases

BACKGROUND

The liver is affected by two of the most common groups of malignant tumours: primary liver tumours and liver metastases from colorectal carcinoma. Liver metastases are significantly more common than primary liver cancer and long-term survival rates reported for patients after radical surgical treatment is approximately 50%. However, R0 resection (resection for cure) is not feasible in the majority of patients. Cryotherapy is performed with the use of an image-guided cryoprobe which delivers liquid nitrogen or argon gas to the tumour tissue. The subsequent process of freezing is associated with formation of ice crystals, which directly damage exposed tissue, including cancer cells.

OBJECTIVES

To assess the beneficial and harmful effects of cryotherapy compared with no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, and six other databases up to June 2018.

SELECTION CRITERIA

Randomised clinical trials assessing beneficial and harmful effects of cryotherapy and its comparators for liver metastases, irrespective of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We extracted information on participant characteristics, interventions, study outcomes, and data on the outcomes important for our review, as well as information on the design and methodology of the trials. Two review authors independently assessed risk of bias in each study. One review author performed data extraction and a second review author checked entries.

MAIN RESULTS

We found no randomised clinical trials comparing cryotherapy versus no intervention or versus systemic treatments; however, we identified one randomised clinical trial comparing cryotherapy with conventional surgery. The trial was conducted in Ukraine. The trial included 123 participants with solitary, or multiple unilobar or bilobar liver metastases; 63 participants received cryotherapy and 60 received conventional surgery. There were 36 women and 87 men. The primary sites for the metastases were colon and rectum (66.6%), stomach (7.3%), breast (6.5%), skin (4.9%), ovaries (4.1%), uterus (3.3%), kidney (3.3%), intestines (1.6%), pancreas (1.6%), and unknown (0.8%). The trial was not reported sufficiently enough to assess the risk of bias of the randomisation process, allocation concealment, or presence of blinding. It was also not possible to assess incomplete outcome data and selective outcome reporting bias. The certainty of evidence was low because of risk of bias and imprecision.The participants were followed for up to 10 years (minimum five months). The trial reported that the mortality at 10 years was 81% (51/63) in the cryotherapy group and 92% (55/60) in the conventional surgery group. The calculated by us relative risk (RR) with 95% Confidence Interval (CI) was: RR 0.88, 95% CI 0.77 to 1.02. We judged the evidence as low-certainty evidence. Regarding adverse events and complications, separately and in total, our calculation showed no evidence of a difference in recurrence of the malignancy in the liver: 86% (54/63) of the participants in the cryotherapy group and 95% (57/60) of the participants in the conventional surgery group developed a new malignancy (RR 0.90, 95% CI 0.80 to 1.01; low-certainty evidence). The frequency of reported complications was similar between the cryotherapy group and the conventional surgery group, except for postoperative pain. Both insignificant and pronounced pain were reported to be more common in the cryotherapy group while intense pain was reported to be more common in the conventional surgery group. However, the authors did not report whether there was any evidence of a difference. There were no intervention-related mortality or bile leakages.We identified no evidence for health-related quality of life, cancer mortality, or time to progression of liver metastases. The study reported tumour response in terms of the carcinoembryonic antigen level in 69% of participants, and reported results in the form of a graph for 30% of participants. The carcinoembryonic antigen level was lower in the cryotherapy group, and decreased to normal values faster in comparison with the control group (P < 0.05).

FUNDING

the trial did not provide information on funding.

AUTHORS' CONCLUSIONS

The evidence for the effectiveness of cryotherapy versus conventional surgery in people with liver metastases is of low certainty. We are uncertain about our estimate and cannot determine whether cryotherapy compared with conventional surgery is beneficial or harmful. We found no evidence for the benefits or harms of cryotherapy compared with no intervention, or versus systemic treatments.

Cryo-Assisted Resection En Bloc, and Cryoablation In Situ, of Primary Breast Cancer Coupled With Intraoperative Ultrasound-Guided Tracer Injection: A Preliminary Clinical Study

The aim of the study was to perform cryosurgery on a primary breast tumor, coupled with simultaneous peritumoral and intratumoral tracer injection of a blue dye, to evaluate lymphatic mapping. We explored the ability of our strategy to prevent tumor cells, but not that of injected tracers, to migrate to the lymphovascular drainage during conventional resection of frozen breast malignancies. Seventeen patients aged 51 (14) years (mean [standard deviation]), presenting primary breast cancer with stage I to IV, were randomly selected and treated in The Rudolfinerhaus Private Clinic in Vienna, Austria, and included in this preliminary clinical study. Under intraoperative ultrasound, 14 patients underwent curative cryo-assisted tumor resection en bloc, coupled with peritumoral tracer injection, which consisted of complete tumor freezing and concomitant peritumor injection with a blue dye, before resection and sentinel lymph node dissection (group A). Group B consists of 3 patients previously refused any standard therapy and had palliative tumor cryoablation in situ combined with intratumoral tracer injection. The intraoperative ultrasound facilitated needle positioning and dye injection timing. In group A, the frozen site extruded the dye that was distributed through the unfrozen tumor, the breast tissue, and the resection cavity for 12 patients. One to 4 lymph nodes were stained for 10 of 14 patients. The resection margin was evaluable. Our intraoperative ultrasound-guided performance revealed the injection and migration of a blue dye during the frozen resection en bloc and cryoablation in situ of primary breast tumors. Sentinel lymph node mapping, pathological determination of the tumor, and resection margins were achievable. The study paves the way for intraoperative cryo-assisted therapeutic strategies for breast cancer.

CT-guided percutaneous cryoablation for palliative therapy of gastric cancer liver metastases

OBJECTIVE

Liver metastases occur in approximately 4%-14% of gastric cancer patients and are associated with high mortality. However, no standardized treatment approach is available for these patients. We aimed to assess the clinical outcomes of patients with gastric cancer liver metastases (GCLM) who underwent percutaneous cryoablation.

METHODS

We retrospectively enrolled 19 patients with 27 metastatic hepatic tumors who underwent cryoablation for liver metastases after gastrectomy for primary gastric cancer. Complications, overall survival (OS), local tumor progression-free survival (PFS), recurrence rates, and quality of life were assessed.

RESULTS

After cryoablation therapy, the median OS for all 19 patients was 16.0 months (range, 5-50 months), and the 1-, 2-, and 3-year OS rates were 78.9%, 43.4%, and 21.7%, respectively. The median local tumor PFS was 8.0 months (range, 3-24 months), and the local tumor PFS rates at 6 and 12 months were 59.2% and 23.2%, respectively. Overall, patients' quality of life improved after cryoablation therapy (P < 0.05). Complications in this study were mild; no severe complications caused by technique were detected.

CONCLUSIONS

Cryoablation provided good local control, improved patients' quality of life and had a low complication rate. Our research showed that cryoablation may be an effective palliative treatment for GCLM.

Clinical Practice Guidelines for Cryosurgery of Pancreatic Cancer: A Consensus Statement From the China Cooperative Group of Cryosurgery on Pancreatic Cancer, International Society of Cryosurgery, and Asian Society of Cryosurgery

Pancreatic cancer (PC), one of the most lethal malignancies, accounts for 8% to 10% of digestive system cancers, and the incidence is increasing. Surgery, chemotherapy, and radiotherapy have been the main treatment methods but are not very effective. Cryosurgery was first used in 1984 for treatment of locally advanced PC and has since become a considerable treatment for most cases of unresectable PC. During the past decade, cryosurgery has been applied in some hospitals in China, and the newly developed technique of computed tomography- and/or ultrasound-guided percutaneous cryosurgery has shown better results than chemotherapy in cases of unresectable locally advanced PC, with the 1-year survival rate reported to be more than 50%. To develop standardized criteria for the application of cryosurgery in PC, the International Society of Cryosurgery and Asian Society of Cryosurgery assembled experts from Austria, Japan, and China to discuss treatment methods and arrive at a consensus on the indications, contraindications, and preferred techniques of PC cryosurgery.

Thermal Ablation in the Management of Colorectal Cancer Patients with Oligometastatic Liver Disease

BACKGROUND

Surgical resection of limited colorectal liver disease improves long-term survival and can be curative in a subset of selected cases. Image-guided percutaneous ablation therapies have emerged as safe and effective alternative options for selected patients with unresectable colorectal liver metastases (CLM) that can be ablated with margins. Ablation causes focal destruction of tissue and has increasingly been shown to provide durable eradication of tumors.

METHODS

A selective review of literature was conducted in PubMed, focusing on recent studies reporting on the safety, efficacy, and long-term outcomes of percutaneous ablation modalities in the treatment of CLM. The present work gives an overview of the different ablation techniques, their current clinical indications, and reported outcomes from most recently published studies. The 'test of time' concept for using ablation as a first local therapy is also described.

RESULTS

There are several thermal ablative tools currently available, including radiofrequency ablation (RFA), microwave ablation, and cryoablation. Most data to date originated from the application of RFA. Adjuvant thermal ablation in the treatment of oligometastatic colon cancer liver disease offers improved oncologic outcomes. The ideal CLM amenable to percutaneous ablation is a solitary tumor with the largest diameter up to 3 cm that can be completely ablated with a sufficient margin. 5-year overall survival rates up to 70% after ablation of unresectable CLM have been reported. Pathologic confirmation of complete tumor necrosis with margins over 5 mm provides best long-term local tumor control by thermal ablation.

CONCLUSION

Current evidence suggests that percutaneous ablation as adjuvant to chemotherapy improves oncologic outcomes of patients with CLM. For small tumors that can be ablated completely with clear margins, percutaneous ablation may offer outcomes similar to those of surgery.

Impact of surgical margin clearance for resection of secondary hepatic malignancies

Over the past several decades, there has been increasing discussion regarding the optimal management of secondary liver malignancies. Traditionally, resection has only been recommended if it could be accomplished with negative microscopic margins of at least 10 mm. However, many investigators have pushed this limit to offer resection to patients with narrower margins. We review the data regarding the impact of margin clearance on outcomes for patients undergoing hepatic metastasectomy.

Cancer immunotherapy using tumor cryoablation

Cryoablation is increasingly being used as a primary treatment for localized cancers and as a salvage therapy for metastatic cancers. Anecdotal clinical reports and animal experiments have confirmed an induction of systemic antitumor immune response by tumor cryoablation. To capitalize on the stimulatory effects of cryoablation for cancer immunotherapy, this response must be intensified using other immunomodulatory agents. This article reviews the preclinical and clinical evidence and discusses the mechanism of the antitumor immune response generated by cryoablation. The rationale and evidence behind several immunotherapy approaches that can be combined with cryoablation to devise a cryoimmunotherapeutic strategy with a potential to impact the progression of metastatic disease are described.

Cryosurgery for pancreatic cancer

The procedure of pancreatic cryosurgery is performed with intraoperative or percutaneous approaches. Based on current data and our initial experience, cryoablation appears to be a feasible, potentially safe and promising option in patients with locally advanced and unresectable pancreatic cancer. It is suggested that there are almost no known contraindications to the use of cryosurgery for pancreatic cancer. For most patients with pancreatic cancer, cryosurgery can substitute conventional surgery.

Cryotherapy for liver metastases

BACKGROUND

Primary liver tumours and liver metastases from colorectal carcinoma are the two most common malignant tumours to affect the liver. The liver is second only to the lymph nodes as the most common site for metastatic disease. More than half of the patients with metastatic liver disease will die from metastatic complications. In cryoablation, liquid nitrogen or argon gas is delivered to the liver tumour, guided by ultrasound using a specially designed probe. Ice crystal formation during the rapid freezing process causes destruction of cellular structure and kills the tumour cells.

OBJECTIVES

To study the beneficial and harmful effects of cryotherapy compared with no intervention, other ablation methods, or systemic treatments in patients with liver metastases.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS, and CINAHL up to December 2012.

SELECTION CRITERIA

We included all randomised clinical trials assessing the beneficial and harmful effects of cryotherapy and its comparators, irrespective of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We extracted relevant information on participant characteristics, interventions, study outcomes, and data on the outcomes for our review, as well as information on the design and methodology of the trials. Bias risk assessment of and data extraction from the trials fulfilling the inclusion criteria were done by one author and checked by a second author.

MAIN RESULTS

One randomised clinical trial fulfilled the inclusion criteria of the review. The trial was judged as a trial with high risk of bias due to the unclear report on the generation of the allocation sequence and allocation concealment, blinding, incomplete outcome data and the selective outcome reporting domain. The trial included 123 consecutive patients with solitary or multiple unilobar or bilobar liver metastases who were randomised into two groups, 63 received cryotherapy and 60 received conventional surgery. There were 36 females and 87 males. The primary sites for the metastases were colorectal (66.6%), stomach (7.3%), breast (6.5%), melanoma (4.9%), ovarian adenocarcinoma (4.1%), uterus (3.3%), kidney (3.3%), intestinal (1.6%), pancreatic (1.6%), and unknown (0.8%). The tumours were resectable and non-resectable.The patients were followed for up to 10 years (minimum five months). Mortality at the last follow-up was 81% (51/63) in the cryotherapy group and 92% (55/60) in the conventional surgery group (RR 0.88; 95% CI 0.77 to 1.02); that is, no statistically significant difference was observed. In the cryotherapy group, 60%, 44%, and 19% of the participants survived 3, 5, and 10 years respectively, while in the conventional surgery group the percentages were 51%, 36%, and 8%. The hazard ratio calculated using the Parmar method was 0.71 (95% confidence interval (CI) 0.47 to 1.09). Recurrence in the liver was observed in 86% (54/63) of the patients in the cryotherapy group and 95% (57/60) of the patients in the conventional surgery group (relative risk (RR) 0.9; 95% CI 0.8 to 1.01); that is, no statistically significant difference was observed. Frequency of reported complications was similar between the cryotherapy group and the conventional surgery group except for postoperative pain. Both insignificant and pronounced pain were reported to be more common in the cryotherapy group while intense pain was reported to be more common in the control group. However, it was not reported by the authors whether the differences were significant. No intervention-related mortality and no bile leakage were observed.

AUTHORS' CONCLUSIONS

On the basis of one randomised clinical trial with high risk of bias, there is insufficient evidence to conclude if in patients with liver metastases from various primary sites cryotherapy brings any significant benefit in terms of survival or recurrence compared with conventional surgery. In addition, there is no evidence for the effectiveness of cryotherapy when compared with no intervention. At present, cryotherapy cannot be recommended outside randomised clinical trials.

Clinical outcome, proteome kinetics and angiogenic factors in serum after thermoablation of colorectal liver metastases

Background

Thermoablation is used to treat patients with unresectable colorectal liver metastases (CRLM). We analyze clinical outcome, proteome kinetics and angiogenic markers in patients treated by cryosurgical ablation (CSA) or radiofrequency ablation (RFA).

Methods

205 patients underwent CSA (n = 20), RFA (n = 22), partial hepatectomy (PH, n = 134) or were found truly unresectable (n = 29). Clinical outcome, proteome transitions and angiogenic response in serum were analyzed at various time points after ablation.

Result

Median overall survival in CSA patients (17.6 months) was worse (p < 0.0001) when compared to RFA treated patients (51.7 months) and patients after PH (43.4 months). The complication rate was higher in the CSA group (50%) as compared to the RFA group (22%). Proteomics analyses showed consistently more changes in serum protein abundance with CSA compared to RFA. In the first four days after ablation a pro-angiogenic serum response occurred.

Conclusions

RFA of CRLM is superior to CSA with a median survival which equals survival in patients after PH. Proteomics analyses suggests a more aggravated serum response to CSA compared to RFA. Thermoablation is associated with changes in serum levels of angiogenic factors favouring a pro-angiogenic environment, but without differences between RFA and CSA.

Pleural tumor seeding following percutaneous cryoablation of hepatocellular carcinoma

Numerous modalities for hepatic tumor ablation are currently used including ethanol injection, radiofrequency ablation (RFA), cryoablation, and microwave ablation. The results and complications of these various tumor ablation techniques have been reported extensively, with the most data existing for percutaneous RFA. One of the most serious complications from tumor ablation is the seeding of cancer cells along the ablation tract. The incidence and risk factors for tract seeding in RFA have been reported, but little information regarding this complication with other ablation modalities has been reported. We report a case of tumor seeding into the pleural space following percutaneous cryoablation of hepatocellular carcinoma (HCC).

Evidence for tumor cell spread during local hepatic ablation of colorectal liver metastases

INTRODUCTION

The aim of the present study was to analyze the impact of cryosurgery (CRYO) on liver metastases compared to other thermoablative techniques. In a rat liver metastases model, evidence for tumor cell spread was analyzed comparing CRYO, radiofrequency ablation (RFA), and laser-induced thermotherapy (LITT).

METHODS

In an experimental study, we compared cell spillage in the washout of isolated perfused rat livers undergoing thermal ablation. Within the same model, CC531-GFP rat liver tumors were treated with CRYO, RFA, or LITT and the number of vital tumor cells within the perfusate was measured. Matrix metalloproteinases (MMP-2, MMP-9) were analyzed after in vivo ablation of rat colorectal liver metastases in the third experimental model.

RESULTS

Our data showed pronounced washout of cells after CRYO with a higher amount of intravascular cells and cell detritus compared to RFA and LITT. Only the effluent fluid of cryosurgery-treated livers revealed GFP-stained tumor cells. MMP-2 and MMP-9 expression was significantly higher after cryosurgery than after RFA and LITT.

CONCLUSION

When using thermoablative techniques, intravascular metastatic cell spillage is highest in CRYO, and increased expression of matrix metalloproteinases may further facilitate tumor cell spread. Therefore, RFA and LITT may be preferable whenever surgical resection of liver tumors is impossible.

Percutaneous ablation in the kidney

Percutaneous ablation in the kidney is now performed as a standard therapeutic nephron-sparing option in patients who are poor candidates for resection. Its increasing use has been largely prompted by the rising incidental detection of renal cell carcinomas with cross-sectional imaging and the need to preserve renal function in patients with comorbid conditions, multiple renal cell carcinomas, and/or heritable renal cancer syndromes. Clinical studies to date indicate that radiofrequency ablation and cryoablation are effective therapies with acceptable short- to intermediate-term outcomes and with a low risk in the appropriate setting, with attention to pre-, peri-, and postprocedural detail. The results following percutaneous radiofrequency ablation and cryoablation in the treatment of renal cell carcinoma are reviewed in this article, including those of several larger scale studies of ablation of T1a tumors. Clinical and technical considerations unique to ablation in the kidney are presented, and potential complications are discussed.

Ablative therapies for colorectal liver metastases: a systematic review

AIM

The standard treatment for colorectal liver metastases (CRLM) is surgical resection. Only 20-30% of patients are deemed suitable for surgery. Recently, much attention has focused on ablative therapies either to treat unresectable CRLM or to extend the margins of resectability. This review aims to assess the long-term outcome and complication rates of various ablative therapies used in the management of CRLM.

METHOD

A literature search was performed of electronic databases including Medline, Cochrane Collaboration Library and the National Library of Medicine's ClinicalTrials.gov. Inclusion criteria were ablation for CRLM with minimum 1 year follow-up and >10 patients, published between January 1994 and January 2010.

RESULTS

In all, 226 potentially relevant studies were identified, of which 75 met the inclusion criteria. Cryotherapy (26 studies) had local recurrence rates of 12-39%, with mean 1-, 3- and 5-year survival rates of 84%, 37% and 17%. The major complication rate ranged from 7% to 66%. Microwave ablation (13 studies) had a local recurrence rate of 5-13%, with a mean 1-, 3- and 5-year survival of 73%, 30% and 16%, and a major complication rate ranging from 3% to 16%. Radiofrequency ablation (36 studies) had a local recurrence rate of 10-31%, with a mean 1-, 3- and 5-year survival of 85%, 36% and 24%, with major complication rate ranging from 0% to 33%.

CONCLUSION

Ablative therapies offer significantly improved survival compared with palliative chemotherapy alone with 5-year survival rates of 17-24%. Complication rates amongst commonly used techniques are low.

Cryotherapy for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is the most common primary malignant cancer of the liver. Evidence for the role of cryotherapy in the treatment of hepatocellular carcinoma is controversial.

OBJECTIVES

The aim of this review is to evaluate the potential benefits and harms of cryotherapy for the treatment of hepatocellular carcinoma.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and LILACS until June 2009. We identified further studies by searching national and topic-specific databases, bibliographies, conference abstracts, journals, and grey literature. Furthermore, we reviewed the reference lists and contacted the principal authors of the identified studies.

SELECTION CRITERIA

Randomised clinical trials (irrespective of language or publication status) comparing cryotherapy with or without co-intervention(s) to placebo, no treatment, or other control interventions were considered for the review. Due to the absence of randomised clinical trials, we searched for quasi-randomised studies as well as prospective cohort studies and retrospective cohort studies.

DATA COLLECTION AND ANALYSIS

Two authors independently identified and assessed studies for their fulfilment of the inclusion criteria. Dichotomous data were expressed as risk ratio (RR) with 95% confidence intervals (CI). We performed the review following the recommendations of The Cochrane Collaboration.

MAIN RESULTS

We were unable to identify any randomised clinical trials. We were also unable to identify quasi-randomised trials. Instead, we identified two prospective cohort studies and two retrospective cohort studies. However, only one of these studies could be included for the assessment of benefit as the study results were stratified according to both the type of hepatic malignancy (primary or secondary) and the intervention group. This retrospective study compared percutaneous cryotherapy with percutaneous radiofrequency. The remaining studies were excluded for the analyses of benefit but included for the assessment of harm. Both severe and non-severe adverse events were reported, but the true nature and extent of harm was difficult to asses.

AUTHORS' CONCLUSIONS

At present, there is no evidence to recommend or refute cryotherapy for patients with hepatocellular carcinoma. Randomised clinical trials with low-risk of bias may help in defining the role of cryotherapy in the treatment of hepatocellular carcinoma.

Cryoimmunotherapy in urologic oncology

Cryoablation is gaining acceptance as a primary treatment of localized as well as a salvage therapy of metastatic urologic malignancies. Anecdotal clinical reports suggest cryoablation can induce a systemic anti-tumor immune response; this phenomenon has been confirmed in animal models. To capitalize on this stimulatory effect of cryotherapy for control of advanced malignancies, it must be further intensified. This article reviews the existing evidence regarding cryoimmunology and discusses the mechanisms for generation of an anti-tumor immune response. Several immunotherapy approaches that can be combined with cryoablation to devise a cryoimmunotherapeutic strategy with potential to affect the progression of metastatic disease are described.

Cryosurgery for the treatment of heel pain

BACKGROUND

Although cryosurgery has been used to treat certain conditions, its efficacy for the treatment of heel pain has not been established. The objective of this retrospective case series was to investigate both short- and long-term changes in heel pain after cryosurgery.

MATERIALS AND METHODS

A sample of 137 feet (n = 137) was analyzed over a 24-month period after cryosurgery. The mean age was 56 years and the mean BMI was 33. Subjects in our analysis included only those who had failed 6 months of conservative care prior to cryosurgery. Pain was measured using a Numeric Pain Scale (NPS, zero to 10) at 3 weeks and 24 months. Statistics were calculated using SPSS version 12.0 (Chicago, IL).

RESULTS

A total of 106 subjects had successful pain relief and 31 subjects failed to gain relief; the success and failure rates were 77.4% and 22.6%, respectively. Mean pain before cryosurgery was 7.6, after cryosurgery at three weeks was 1.6 (p < 0.0005), and after cryosurgery at 24 months was 1.1 (p < 0.0005).

CONCLUSION

In subjects who achieved successful pain relief, the significantly lower mean pain score at 3 weeks and 24 months, compared to the initial pain score prior to cryosurgery, suggests that cryosurgery was successful in resolving both short- and long-term heel pain.

[Metastases of colorectal carcinoma]

Metastases of colorectal cancer represent an interdisciplinary therapeutic challenge. Evidence-based guidelines are supportive of treatment decisions in specific situations with the objective to improve the therapeutic outcome for patients. Interventional tumor therapies are increasingly applied therapeutic options in the treatment of colorectal metastases. The current literature indicates that thermoablation of colorectal liver metastasis can lead to an improved survival in selected patients. However, recommendation of thermoablation as a part of guidelines for the therapy of colorectal metastases is restricted due to a shortcoming of randomized controlled trials. Therefore, interventional tumor therapies have to be evaluated in comparison with standard therapies, particularly with regard to surgical resection and chemotherapy. Moreover, the interdisciplinary combination of tumor ablation, surgical resection, and chemotherapy is a promising approach for the optimization of oncological therapy strategies in the treatment of colorectal metastases.

Resection versus no intervention or other surgical interventions for colorectal cancer liver metastases

BACKGROUND

About one in four of patients with metastatic colorectal cancer have metastases isolated to the liver, of which 10% to 25% are eligible for ablation of the liver metastases, improving the five year survival rate. Treatments include hepatic resection and other modalities using cryosurgery and radiofrequency thermal ablation. Although new modalities allow safe ablation of liver metastases without the need for surgical intervention, there are still no clear guidelines on the appropriate management of patients with colorectal cancer and hepatic metastases.

OBJECTIVES

The primary objectives were to compare resection of liver metastases to no intervention and other modalities of intervention (including cryosurgery and radiofrequency ablation) in terms of the benefits and harms for each intervention.

SEARCH STRATEGY

Searches were conducted of the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE databases up to October 2006. In addition, references were scrutinized in identified eligible trials.

SELECTION CRITERIA

Only randomized controlled trials reporting patients (regardless of age and sex) who had had curative surgery for adenocarcinoma of the colon or rectum, had been diagnosed with liver metastases and who were eligible for liver resection (i.e. with no evidence of primary or metastatic cancer elsewhere) were considered.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a form designed for this review. Discrepancies were resolved by consensus.

MAIN RESULTS

Only one trial involving 123 people (87 male 36 female) was included. The data from this ten year prospective, randomized clinical trial suggest that hepatic cryosurgery is effective in the treatment of resectable and nonresectable liver metastases. The results show intra-operative tumor reduction (>/=90% or </= 97%) and extended higher survival in these patients. The study indicated a five year and ten year survival rate of 44% and 19% after cryosurgery, respectively. However, it was not possible to separate out and unravel the outcomes data that related only to the participants (66.6%) with liver metastases from colorectal cancer as opposed to those with liver metastases from other primary tumors.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to support a single approach, either surgical or non-surgical, for the management of colorectal liver metastases. Therefore, treatment decisions should continue to be based on individual circumstances and clinician's experience. The authors conclude that local ablative therapies are probably useful, but that they need to be further evaluated in a randomized controlled trial.

Cryosurgery: early ultrastructural changes in liver tissue in vivo

BACKGROUND

Experimental observations with regard to freezing in vitro cell lines and fluid systems led to the application of low temperatures to in vivo biological systems. For the first time, this report describes the cryosurgical response of liver parenchyma and the early ultrastructural cellular changes in liver tissue, i.e., cryosurgery, in vivo.

MATERIALS AND METHODS

Forty-eight animals were used for the experiment. The dogs were divided into four groups. In group A, the liver tissue was frozen to -80 degrees C and in group B, to -180 degrees C. Temperatures of -80 degrees C and -180 degrees C in contact with liver tissue was selected for cryosurgical exposure. For transmission electron microscopy, the specimens were taken immediately and 1 h after the finishing of the freeze-thaw cycles intraoperatively. Further, the next specimens were taken in 24 h, this time also intraoperatively.

RESULTS

The electronic microscopic analysis showed that, after local cryodestruction at temperatures of -80 degrees C and -180 degrees C, similar processes occurred within the liver tissue in the early postcryosurgical phase-immediately and 1 h after cryosurgical session. The hepatocytes in the center of the cryozone changed upon thawing. Ultrastructural changes in the hepatic cells, where the first signs of dystrophic processes had been noticed, were increased.

CONCLUSIONS

Our new insights prove on the cell level that suddenly and progressively damaged liver cells in the postcryosurgical zone lead to aseptic cryoaponecrosis and then to aseptic cryoapoptosis of vital normal tissue. The vascular capillary changes and circulatory stagnation demonstrate together with cryoaponecrosis and cryoapoptosis the anti-angiogenesis mechanisms, which are some of the main mechanisms of biological tissue injury following the low temperature exposure.

Percutaneous cryosurgery for the treatment of hepatic colorectal metastases

AIM: To determine the safety and efficacy of efficacy of percutaneous cryosurgery for treatment of patients with hepatic colorectal metastases.

METHODS: Three hundred and twenty-six patients with non-resectable hepatic colorectal metastases underwent percutaneous cryosurgery under the guidance of ultrasound or CT. Follow-up was 1 mo after cryosurgery and then every 4 mo thereafter by assessment of tumor markers, liver ultrasonography, and abdominal CT. For lesions suspicious of recurrence, a liver biopsy was performed and subsequent repeat cryosurgery was given if histology was positive for cancer.

RESULTS: All patients underwent a total of 526 procedures of cryosurgery. There were 151 patients who underwent repeat procedures of cryosurgery for recurrent tumors in the liver and extrahepatic places. At 3 mo after cryosurgery, carcinoembryonic antigen (CEA) levels in 197 (77.5%) patients who had elevated markers before cryosurgery decreased to normal range. Among 280 patients who received CT following-up, cryotreated lesions showed complete response (CR) in 41 patients (14.6%), partial response (PR) in 115 patients (41.1%), stable disease (SD) in 68 patients (24.3%) and progressive disease (PD) in 56 patients (20%). The recurrence rate was 47.2% during a median follow-up of 32 mo (range, 7-61). Sixty one percent of the recurrences were seen in liver only and 13.9% in liver and extrahepatic areas. The recurrence rate at cryotreated site was only 6.4% for all cases. During a median follow-up of 36 mo (7-62 mo), the median survival of all patient was 29 mo (range 3-62 mo). Overall survival was 78%, 62%, 41%, 34% and 23% at 1, 2, 3, 4 and 5 years, respectively, after the treatment. Patients with tumor size less than 3 cm, tumor in right lobe of liver, lower CEA levels (< 100 ng/dL) and post-cryosurgery TACE had higher survival rate. There was no significant difference in terms of survival based on the number of tumors, pre-cryosurgery chemotherapy and the timing of the development of metastases (synchronous vs metachronous). Patients who underwent 2-3 procedures of cryosurgery had increased survival compared to patients who received cryosurgery once only. There was no intra-cryosurgery mortality. Main adverse effects, such as hepatic bleeding, cryoshock, biliary fistula, liver failure, renal insufficiency and liver abscess were only observed in 0.3%-1.5% of patients.

CONCLUSION: Percutaneous cryosurgery was a safe modality for hepatic colorectal metastases. Rather than an alternative to resection, this technique should be regarded as a complement to hepatectomy and as an additional means of achieving tumor eradication when total excision is not possible.

WITHDRAWN: Resection versus no intervention or other surgical interventions for colorectal cancer liver metastases

BACKGROUND

About one in four of patients with metastatic colorectal cancer have metastases isolated to the liver, of which 10-25% are eligible for ablation of the liver metastases, improving the 5-year survival rate. Treatments include hepatic resection and non-surgical tumor ablation using cryosurgery and radiofrequency thermal ablation. Although new modalities allow safe ablation of liver metastases without the need for surgical intervention, there are still no clear guidelines on the appropriate management of patients with colorectal cancer and hepatic metastases.

OBJECTIVES

The primary objectives were to compare resection of liver metastases to no intervention and other modalities of intervention (including cryosurgery and radiofrequency ablation), in terms of the benefits and harms for each intervention.

SEARCH STRATEGY

We identified randomized controlled trials from MEDLINE, Embase, and the Cochrane Controlled Trials Register up to October 2006, based upon the search strategy developed for MEDLINE, and revised appropriately for each database. In addition, references were scrutinized in identified eligible trials.

SELECTION CRITERIA

We only considered randomized controlled trials reporting patients of any age and sex, who have had curative surgery for adenocarcinoma of the colon or rectum, diagnosed with liver metastases that are candidates for liver resection, i.e., with no evidence of primary or metastatic cancer elsewhere.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality using a data-extraction form designed for this review. Discrepancies were resolved in consensus.

MAIN RESULTS

Only one trial fulfilled our inclusion criteria. The data of this 10-year prospective, randomized clinical trial suggest that hepatic cryosurgery is effective in the treatment of resectable and non-resectable liver metastases. The results show intra-operative tumor reduction (> or = 90% < or = 97%) and extended higher survival in these patients. The study indicated a 5-year and 10-year survival rate of 44% and 19% after cryosurgery, respectively. However, it was not possible to separate out and unravel the outcomes data that related only to the participants (66.6%) with liver metastases from colorectal cancer as opposed to those with liver metastases from other primary tumors.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to support a single approach, either surgical or non-surgical for the management of colorectal liver metastases. Therefore, treatment decisions should continue to be based on individual circumstances and clinician's experience. We concede that local ablative therapies are probably useful, but they need to be further evaluated in a randomized controlled trial.

Cryosurgery: ultrastructural changes in pancreas tissue after low temperature exposure

A number of theoretical and experimental studies, both in vitro and in vivo, have been performed to explain the action of low temperatures on tissue. It is now evident that the thermal parameters used in the past for freezing during cryosurgery were not precise; this may have resulted in the failure of treatment. For the first time, this report describes the early ultrastructural features of pancreatic parenchyma after low temperature exposure, i.e., cryosurgery, in vivo. We demonstrate the effect of freeze-thawing processes using temperatures of various intensities. The cryosurgical response of pancreas parenchyma, i.e., ultrastructural cellular changes in pancreas tissue, was investigated. The electronic microscopic analysis showed that, after local cryodestruction at temperatures of -80 degrees C and -180 degrees C, similar processes occurred within the pancreas tissue in the early postcryosurgical phase -- immediately and up to 24 hours after low temperature exposure on tissue. The exocrine pancreatic cells in the center of the cryozone changed upon thawing. Ultrastructural changes in the exocrine pancreatic cells, where the first signs of dystrophic processes had been noticed, were increased. These ultrastructural changes in the pancreatic cells provide a platform to better understand the mechanisms of damage and the pathogenesis of frostbite after cryosurgery. The properties of the pancreas parenchyma response after low temperature exposure provide important insights into the mechanisms of damage and the cryogenic lesion immediately after thawing in cryosurgery. Our new insights prove on the cell level that suddenly and progressively damaged pancreatic cells in the postcryosurgical zone lead to aseptic cryonecrosis and then to aseptic cryoapoptosis of vital normal tissue. The vascular capillary changes and circulatory stagnation demonstrate the anti-angiogenesis mechanism, which, together with cryoaponecrosis and cryoapoptosis, are some of the main mechanisms of biological tissue injury following the low temperature exposure.

Recurrence and Survival Outcomes after Hepatic Resection with or without Cryotherapy for Liver Metastases from Colorectal Carcinoma

BACKGROUND

Some reports support resection combined with cryotherapy for patients with multiple bilobar colorectal liver metastases (CRLM) that would otherwise be ineligible for curative treatments. This series demonstrates long-term results of 415 patients with CRLM who underwent resection with or without cryotherapy.

METHODS

Between April 1990 and January 2006, 291 patients were treated with resection only and 124 patients with combined resection and cryotherapy. Recurrence and survival outcomes were compared. Kaplan-Meier and Cox-regression analyses were used to identify significant prognostic indicators for survival.

RESULTS

Median length of follow-up was 25 months (range 1-124 months). The 30-day perioperative mortality rate was 3.1%. Overall median survival was 32 months (range 1-124 months), with 1-, 3- and 5-year survival values of 85%, 45% and 29%, respectively. The overall recurrence rates were 66% and 78% for resection and resection/cryotherapy groups, respectively. For the resection group, the median survival was 34 months, with 1-, 3- and 5- year survival values of 88%, 47% and 32%, respectively. The median survival for the resection/cryotherapy group was 29 months, with 1-, 3- and 5-year survival values of 84%, 43% and 24%, respectively (P = 0.206). Five factors were independently associated with an improved survival: absence of extrahepatic disease at diagnosis, well- or moderately-differentiated colorectal cancer, largest lesion size being 4 cm or less, a postoperative CEA of 5 ng/ml or less and absence of liver recurrence.

CONCLUSIONS

Long-term survival results of resection combined with cryotherapy for multiple bilobar CRLM are comparable to that of resection alone in selected patients.

Cryosurgery for resectable and unresectable hepatic metastases from colorectal cancer

AIMS

Hepatic cryosurgery is useful for patients with hepatic metastases from colorectal cancer confined to the liver but considered unresectables because of the number and location of lesions. While encouraging results were reported following cryosurgery for unresectable liver metastases we considered particularly valuable to examine the safety and effectiveness of cryosurgery in patients with resectable and unresectable metastases from colorectal cancer.

METHODS

Between January 1997 and September 2005, 53 patients with liver metastases from colorectal cancer underwent hepatic cryosurgery at our institution. Hepatic metastases were resectable in 31 (58.5%) patients and unresectable in 22 (41.5%).

RESULTS

A total of 136 liver metastases were treated in 53 patients. The size of treated lesions ranged from 0.5 to 10 cm (mean 2.7). There were 2 postoperative deaths (3.8%) from massive bleeding and from cryoshock. The overall morbidity rate was 66%. The median follow-up was 24.8 months. The overall survival rate at 12 months was 86.1%, at 48 months it was 27%. No significant difference was found between survival rates in patients with resectable or unresectable metastases. Among 31 patients with resectable liver metastases 7 (22.6%) patients developed recurrence at the site of cryosurgery.

CONCLUSION

Survival rates were comparables between patients with resectable and unresectable metastases but a high complication rate and a substantial rate of local recurrence following cryosurgery should caution against its use to treat resectable disease.

Recurrence after Complete Cryoablation of Colorectal Liver Metastases: Analysis of Prognostic Features

This study critically evaluated the prognostic determinants for disease-free survival (DFS) after cryoablation for colorectal liver metastases. An observational cohort study of prospectively collected data on 135 patients who underwent cryoablation with or without resection for colorectal liver metastases was performed. Univariate and multivariate analyses were used to determine the prognostic factors for overall DFS, cryosite DFS, remaining liver DFS, and extrahepatic DFS. Overall, 115 patients (85%) developed recurrence at the cryosite (44%), and the remaining patients developed recurrence at the liver (62%) and extrahepatic site (71%). In univariate analysis, pre-operative and postoperative carcinoembryonic antigen (CEA) were significant for overall DFS. Distribution of metastases, operation type, total number of metastases, number of cryotreated metastases, largest size of cryotreated metastasis, and postoperative CEA were significant for cryosite DFS. The number of cryotreated metastases and postoperative CEA were significant for remaining liver DFS. The largest size of cryotreated metastasis, and preoperative and postoperative CEA were significant for extrahepatic DFS. In multivariate analysis, resection plus cryoablation, ≤7 liver metastases and ≤3 cm cryotreated metastasis were independently associated with an improved cryosite DFS. Preoperative CEA of ≤5 ng/mL was independently associated with an improved overall and extrahepatic DFS. The role of CEA in colorectal metastasis is important. Resection plus cryoablation rather than cryoablation alone should be used for larger lesions.

Complement depletion enhances pulmonary inflammatory response after liver injury

Hepatic cryoablation can produce acute lung injury, with activation of nuclear factor (NF)-kappaB in the remnant liver and lungs, production of C-X-C chemokines, and neutrophil infiltration of the lungs. Activated complement stimulates NF-kappaB and cytokine secretion from Kupffer cells. The role of complement in the development of acute lung injury after cryoablation was examined using HLL transgenic mice (5'HIV-LTR-Luciferase gene; 5' HIV-LTR is an NF-kappaB-dependent promoter). Total complement depletion was achieved with preoperative administration of cobra venom factor (CVF). After hepatic cryoablation, bioluminescent NF-kappaB activity increased in the nonablated liver remnant by 4 hours in both control (119,093 +/- 22,808 net RLU/mg protein) and CVF-treated mice (117,722 +/- 14,932) from cumulative baseline (657 +/- 90, P < 0.0001). In the lung, complement-depletion induced significantly greater increases in NF-kappaB activation at both early and later times. Likewise, chemokines were higher in complement-depleted mice relative to controls (KC: 493 +/- 43 versus 269 +/- 29 pg/mg protein, P < 0.001; MIP-2: 171 +/- 29 versus 64 +/- 13 pg/mg protein, P < 0.0001). Pulmonary myeloperoxidase activity was equivalent at 24 hours, but complement-depletion caused a significantly more rapid influx of neutrophils. Complement depletion results in increased pulmonary inflammation following liver cryo injury via relative upregulation of NF-kappaB activity. Activated complement is not the initiator of the systemic inflammatory response; in fact, downstream components of the complement cascade may diminish subsequent inflammation.

[Liver metastases from colorectal cancer. Is the practice of surgery based on the best clinical evidence possible?]

To date, surgical resection remains the only curative treatment for liver metastases from colorectal cancer. However, the evidence supporting this treatment is based on retrospective studies. The lack of level I clinical evidence has stimulated strong interest in identifying the factors predictive of recurrence, and even to use them to create clinical risk scores (assigning one point to each factor for poor prognosis), in which a higher score indicates a poorer prognosis. In the present review, we discuss all these factors, as well as the therapeutic alternatives that improve local disease control. Next, we review all the prospective randomized studies published on this topic, which mainly focus on adjuvant chemotherapy associated with curative surgery with negative margins, with the aim of validating or rejecting this treatment. Lastly, we include the algorithm of the University of California at San Francisco for surgery in liver metastases from colorectal cancer.

Cryotherapy--a mature ablation technique

This article discusses the use of cryotherapy for the treatment of hepatic tumours, from its early origins to the present day. Results of therapy, preoperative assessment, safety, and the pros and cons of its use are described.

Liver resection or cryotherapy for colorectal liver metastases: a prospective case control study

BACKGROUND AND AIMS

While there is promising survival data for cryosurgery of colorectal liver metastases, local recurrence following cryoablation remains a problem. We aimed to compare morbidity and mortality, as well as the recurrence pattern and survival after liver resection and cryotherapy (alone or in combination with resection) for liver metastases.

PATIENTS AND METHODS

Between 1996 and 2002, 168 patients underwent liver resection alone and 55 patients had cryotherapy (25 in combination with liver resection) for colorectal liver metastases. The patient, tumour and operative details were recorded prospectively and the two patient groups were compared regarding morbidity, survival and recurrence.

RESULTS

More patients had a prior liver resection, liver metastases were smaller and less frequently synchronous, morbidity was significantly lower and hepatic recurrence was significantly more frequent in the cryotherapy group. Five-year survival rates following resection and cryotherapy were comparable (23 and 26% respectively), while overall and hepatic recurrence-free survival was inferior following cryotherapy.

CONCLUSION

Cryotherapy is a valuable treatment option for some patients with non-resectable colorectal liver metastases. While survival is comparable to that after resection, higher hepatic recurrence rates following cryotherapy should caution against the use of cryotherapy for resectable disease until the results of randomized controlled trials are available.

Combined resection and radiofrequency ablation for advanced hepatic malignancies: results in 172 patients

Background: Resection combined with radiofrequency ablation (RFA) is a novel approach in patients who are otherwise unresectable. The objective of this study was to investigate the safety and efficacy of hepatic resection combined with RFA.

Methods: Patients with multifocal hepatic malignancies were treated with surgical resection combined with RFA. All patients were followed prospectively to assess complications, treatment response, and recurrence.

Results: Seven hundred thirty seven tumors in 172 patients were treated (124 with colorectal metastases; 48 with noncolorectal metastases). RFA was used to treat 350 tumors. Combined modality treatment was well tolerated with low operative times and minimal blood loss. The postoperative complication rate was 19.8% with a mortality rate of 2.3%. At a median follow-up of 21.3 months, tumors had recurred in 98 patients (56.9%). Failure at the RFA site was uncommon (2.3%). A combined total number of tumors treated with resection and RFA >10 was associated with a faster time to recurrence (P = .02). The median actuarial survival time was 45.5 months. Patients with noncolorectal metastases and those with less operative blood loss had an improved survival (P = .03 and P = .04, respectively), whereas radiofrequency ablating a lesion >3 cm adversely impacted survival (HR = 1.85, P = .04).

Conclusions: Resection combined with RFA provides a surgical option to a group of patients with liver metastases who traditionally are unresectable, and may increase long-term survival.

Multi-organ inflammation after hepatic cryoablation in BALB/c mice

BACKGROUND

There is increasing evidence that injury to the liver can precipitate or exaggerate lung injury. We have previously shown that hepatic cryoablation (cryo) causes activation of nuclear factor (NF)-kappaB, cytokinemia (tumor necrosis factor-alpha, Mouse Macrophage Inflammatory Protein-2 [MIP-2]), and lung inflammation in transgenic HLL (5'HIV-LTR-Luciferase gene) mice and in Sprague-Dawley rats. It has been reported that BALB/c mice are susceptible to traumatic injury and are active immune responders. We tested whether activation of NF-kappaB and the development of multiple-organ inflammation in response to hepatic injury from 35% cryo were demonstrable in the BALB/c mouse.

METHODS

BALB/c mice (n = 9) were anesthetized, and midline laparotomy was performed. Cryoablation was performed with careful isolation of adjacent structures to avoid inadvertent organ injury to the gastrointestinal tract. A freeze-thaw cycle of the left lobe of the liver was induced, encompassing approximately 35% (by weight). Animals were sacrificed at 1, 2, 4, and 24 h after cryoablation. Serum was collected via IVC puncture and liver, lungs, and kidneys were harvested and freeze-clamped. Two animals were sacrificed without undergoing cryo surgery to serve as a baseline control. NF-kappaB activity was monitored by electrophoretic mobility shift assays. MIP-2 levels and Mouse KC levels from tissue and serum were measured using enzyme-linked immunosorbent assay. Organs were submitted for histological review. We characterized lung inflammation induced by cryosurgery by measuring total and differential cell counts in lung lavage fluid 4 h after hepatic cryoablation.

RESULTS

After cryo, NF-kappaB activation was demonstrated in the 1, 2, and 4-h time points by electrophoretic mobility shift assay in the liver and lungs. Mouse KC and MIP-2 levels increased from baseline, peaked at the 4-h time point, and returned to baseline after 24 h in both liver and lung. Lung lavage 4 h after cryoablation showed increased total cells and neutrophilic lung inflammation.

CONCLUSIONS

BALB/c mice demonstrate evidence of multi-organ inflammation in response to 35% hepatic cryo. These data demonstrate that this model provides for assessment of liver-mediated multi-system inflammation after direct liver injury.

The Extent of Cryosurgery Increases the Complication Rate after Hepatic Cryoablation

Although there have been many reports on the use of cryosurgery to ablate hepatic malignancies none have specifically examined the relationship of complication rates to the extent of cryoablation. A retrospective review from January 1997 to May 2002 identified 98 patients treated with hepatic cryotherapy. The extent of the cryosurgery was determined by the total number of lesions (TNL) and total estimated area (TEA) of the lesions from preoperative evaluation by CT scan and intraoperative evaluation by ultrasound. The major complication rate was 11 per cent. The 30-day mortality was 0 per cent, but the late procedure-related mortality was 2 per cent. Increasing the extent of cryotherapy measured by intraoperative ultrasound demonstrated significant increases in the complication rate and length of stay (LOS). With cryoablation of TEA ≥30 cm2 there was a significant increase in the overall complication rate (56% vs 23%; P = 0.003) and LOS (8.8 ± 6.9 vs 6.1 ± 4.2; P = 0.022) compared with TEA <30 cm2. Performance of concurrent procedures also led to a significant increase in complications (69% vs 29%; P = 0.010) and LOS (8.6 ± 6.8 vs 6.0 ± 4.0; P = 0.019). Multivariate analysis, however, showed intraoperative TEA ≥30 cm2 to be the most significant independent predictor of increased complications and prolonged LOS.