Hepatic cryosurgery in treating colorectal metastases

Combination therapy: Meta-analysis of the effects of TACE and cryoablation on hepatocellular carcinoma

BACKGROUND

This study systematically reviews the data for transcatheter arterial chemoembolization (TACE) alone or combined TACE and cryoablation therapy of hepatocellular carcinoma, aiming to provide clinical choice references for treatment of cancer.

METHODS

Electronic databases (PubMed, EMBASE, China National Knowledge Infrastructure, and Google Scholar) were systematically searched to include relevant studies published in English and Chinese between Jan 1, 2000, to July 31, 2017. The analysis was conducted in RevMan 5.3 based on random effects models.

RESULTS

Nineteen trials (n = 1427) were included. Combined TACE and cryoablation therapy had higher survival rate (1-year survival [RR 1.37; 95%-CI 1.26,1.49], 2-year survival [RR 1.50; 95%-CI 1.25,1.79], 3-year survival [RR 1.67; 95%-CI 1.16,2.40]), complete necrosis [RR 2.53; 95%-CI 2.07,3.10] and tumor control [RR 1.57; 95%-CI 1.40,1.75], which is more favorable for long-term efficacy of non-surgical hepatocellular carcinoma. Tumor recurrence of control group was above combination therapy [RR 0.27; 95%-CI 0.17, 0.43]. Compared with transcatheter arterial chemoembolization, effect of combination therapy occurred mainly in the survival, complete necrosis, tumor control, and recurrence. Taking combination therapy was generally more effective than taking TACE only.

CONCLUSION

Compared with TACE only used to treat cancer, combination therapy had the best effect profile in general, and it had better survival in HCC when taking an integrated approach. The prognosis of treatments based on combination therapy is modulated by cryoablation.

Impact of protamine I on colon cancer proliferation, invasion, migration, diagnosis and prognosis

This paper investigates protamine I (PRM1) expression and its effects on proliferation, invasion and migration of colon cancer cells as well as its function in clinical diagnosis and prognosis. Gene chips were used to screen differentially expressed genes. PRM1 expression was detected by Western blotting and quantitative real time-polymerase chain reaction (qRT-PCR). Hematoxylin and eosin (HE) staining and immunohistochemistry were utilized to compare the expression of PRM1 from multiple differentiation levels of colon cancer tissues. Cell viability, cell apoptosis and cell cycle were tested using the MTT assay and flow cytometry. Cell invasion and migration capability were tested using the Transwell assay and wound healing. In vivo effects of PRM1 on colon cancer were explored using a xenograft model. PRM1 expression in serum was detected by enzyme-linked immunosorbent assay (ELISA). The expression level of PRM1 was significantly higher in colon cancer tissues and the staining degree of PRM1 in poorly-differentiated was stronger. pcDNA3.1-PRM1 decreased cell apoptosis while it increased the proliferation, cell invasion and migration. The si-PRM1 group displayed an opposite tendency. The serum PRM1 level was significantly higher and could serve as a diagnostic biomarker for colon cancer.

New Trends in the Surgical Treatment of Colorectal Cancer Liver Metastases

Colorectal cancer is one of the most common solid tumors affecting people around the world. A significant proportion of patients with colorectal cancer will develop or will present with liver metastases. In some of these patients, the liver is the only site of metastatic disease. Thus, surgical treatment approaches are an appropriate and important treatment option in patients with liver-only colorectal cancer metastases. Resection of colorectal cancer liver metastases can produce long-term survival in selected patients, but the efficacy of liver resection as a solitary treatment is limited by two factors. First, a minority of patients with liver metastases have resectable disease. Second, the majority of patients who undergo successful liver resection for colorectal cancer metastases develop recurrent disease in the liver, extrahepatic sites, or both. In this paper, in addition to the results of liver resection for colorectal cancer metastases, we will review the results of cryoablation, heat ablation, and hepatic arterial chemotherapy using a surgically implanted pump. Each of these surgical treatment modalities can produce long-term survival in a subset of patients with liver-only colorectal cancer metastases, whereas systemic chemotherapy used alone rarely results in long-term survival in these patients. While surgical treatments provide the best chance for long-term survival or, in some cases, the best palliation in patients with colorectal cancer liver metastases, it is clear that further improvements in patient outcome will require multimodality therapy regimens.

Local Ablation for Solid Tumor Liver Metastases: Techniques and Treatment Efficacy

BACKGROUND

Treatment options for liver metastases from solid tumors, such as colon cancer, breast cancer, neuroendocrine tumors, and sarcomas, have expanded in recent years and now include nonresection methods.

METHODS

The literature focused on the treatment of liver metastases was reviewed for technique, perioperative, and long-term outcomes specifically related to local ablation techniques for liver metastases.

RESULTS

Ablation modalities have become popular as therapies for patients who are not appropriate candidates for surgical resection. Use of these techniques, alone or in combination with other liver-directed therapies (and often systemic therapy), has extended the rate of survival for patients with liver metastases and, at times, offers nearly equivalent disease-free survival rates to surgical resection.

CONCLUSIONS

Although surgical resection remains the optimal treatment for liver metastasis, local options, including microwave ablation and radiofrequency ablation, can offer similar long-term local control in appropriately selected patients.

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.

Imaging and Imaging-Guided Interventions in the Diagnosis and Management of Hepatocellular Carcinoma (HCC)-Review of Evidence

The imaging of hepatocellular carcinoma (HCC) is challenging and plays a crucial role in the diagnosis and staging of the disease. A variety of imaging modalities, such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI) and nuclear medicine are currently used in evaluating patients with HCC. Although the best option for the treatment of these cases is hepatic resection or transplantation, only 20% of HCCs are surgically treatable. In those patients who are not eligible for surgical treatment, interventional therapies such as transcatheter arterial chemoembolization (TACE), percutaneous ethanol injection (PEI), radio-frequency ablation (RFA), percutaneous microwave coagulation therapy (PMC), laser ablation or cryoablation, and acetic acid injection are indicated. In this paper, we aimed to review the evidence regarding imaging modalities and therapeutic interventions of HCC.

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).

More than just tumor destruction: immunomodulation by thermal ablation of cancer

Over the past decades, thermoablative techniques for the therapy of localized tumors have gained importance in the treatment of patients not eligible for surgical resection. Anecdotal reports have described spontaneous distant tumor regression after thermal ablation, indicating a possible involvement of the immune system, hence an induction of antitumor immunity after thermoinduced therapy. In recent years, a growing body of evidence for modulation of both adaptive and innate immunity, as well as for the induction of danger signals through thermoablation, has emerged. Induced immune responses, however, are mostly weak and not sufficient for the complete eradication of established tumors or durable prevention of disease progression, and combination therapies with immunomodulating drugs are being evaluated with promising results. This article aims to summarize published findings on immune modulation through radiofrequency ablation, cryoablation, microwave ablation therapy, high-intensity focused ultrasound, and laser-induced thermotherapy.

Cryoablation induces greater inflammatory and coagulative responses than radiofrequency ablation or laser induced thermotherapy in a rat liver model

BACKGROUND

Cryoablation (CA), radiofrequency ablation (RFA), and laser induced thermotherapy (LITT) are alternative therapies for patients with unresectable liver tumors. We investigated whether there are different inflammatory and coagulative responses between these techniques.

METHODS

Livers of 48 rats were subjected to either CA, RFA, LITT, or sham operation (n = 12 in each group). Blood was withdrawn before, and 1, 3, 6, and 24 h after ablation. Liver enzymes as well as inflammatory and coagulation parameters were determined. Whole liver sections from the coagulated liver lobe were stained for quantification of necrosis and morphologic examination.

RESULTS

Histologic examination showed similar volume of complete destruction of liver parenchyma after CA, RFA, or LITT. Transaminase levels as well as the inflammatory response upon CA, as reflected by white blood cell count and cytokine levels, were significantly higher than following RFA or LITT. The systemic intravascular procoagulative state in rats that underwent CA, as reflected by platelets, and levels of sensitive markers for activation of coagulation and fibrinolyis, was also significantly higher.

CONCLUSION

CA of liver in rats induces greater inflammatory and coagulative responses than RFA or LITT. The combined activation of inflammation and coagulation may importantly contribute to the higher morbidity after CA.

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.

Post-radiofrequency ablation syndrome after percutaneous radiofrequency of abdominal tumours: one centre experience and review of published works

The aim of this study was to evaluate prospectively post-radiofrequency ablation (RFA) syndrome and to determine its effect on the quality of life in the 15 days after percutaneous RFA treatment. We carried out an internal review board-approved prospective study of the delayed symptoms that occurred after 71 consecutive RFA sessions in 53 patients (12 women and 41 men; age range 45-83 years; mean age 71.6 years) with 45 primary liver tumours, 34 liver metastases, 3 renal cell carcinoma (RCC), 2 residual lesions from RCC after nephrectomy and 1 pancreatic metastases from RCC. Postablation symptoms occurred in 17 of 53 (32%) patients. Six of 17 patients developed low-grade fever (from 37.5 to 38.5 degrees C). Other symptoms included delayed pain (9/17), nausea (7/17), vomiting (3/17), malaise (3/17) and myalgia (1). Postablation syndrome is a common phenomenon after RFA of solid abdominal tumours. Not only in our study but also in the previous ones the occurrence is observed in approximately one-third patients. Patients should be informed that these symptoms are self-limiting after RFA and most patients should be able to resume near-complete preprocedural levels of activity within 10 days after the procedure.

A primer on transarterial, chemical, and thermal ablative therapies for hepatic tumors

BACKGROUND

Surgical resection is the only potentially curative approach for patients with primary and metastatic liver tumors. Unfortunately, most patients with hepatic malignancy are precluded from resection due to multifocal disease, anatomic limitations, inadequate functional liver reserve, extrahepatic metastases, or medical comorbidities. Consequently, several methods of tumor ablation have been developed as alternate treatment strategies for patients with unresectable hepatic tumors or as adjuncts in total cancer therapy. The purpose of this review is to inclusively define the various ablation modalities available (transarterial, chemical, and thermal ablative), and to describe the procedures, general applications, and reported outcomes.

DATA SOURCES

A MEDLINE and CINAHL search of the English-language literature was performed on transarterial, chemical, and thermal ablative therapies.

CONCLUSIONS

Presently, radiofrequency thermal ablation is the most widely applicable liver-directed modality for hepatic tumor ablation, enabling treatment of primary and metastatic tumors. However, other transarterial and thermoablative techniques are available with accumulating data for their use. Lacking at present are studies that define the role and potential benefit of the various liver-directed modalities in the treatment algorithm for hepatic tumors.

The Role of Radiofrequency Ablation in Multiple Liver Metastases to Debulk the Tumor: A Pilot Study before Alternative Therapies

INTRODUCTION

In this study, our aim was to proceed with the first study of our patients by evaluating different metastatic tumor to the liver to check whether, after debulking the tumor with radiofrequency ablation (RFA), the chemotherapy, could increase the survival in these patients as a pilot study before applying alternative therapies in the future.

MATERIALS AND METHODS

We studied 11 patients, 7 male, 4 female; age mean, 68 years (50-84). The tumors considered were carcinoid (3), gastrinoma (3), a new endocrine of unknown origin (2), colorectal (2), and breast (1).

RESULTS

All of the patients underwent laparoscopic RFA with a prior confirmatory biopsy and were discharged after 23 hours. No pain, bleeding, or wound infections were reported. One (1) patient with a gastrinoma died 9 months following surgery from a myocardial infarction. All other patients are still alive, although 2 experienced hepatic recurrences.

CONCLUSIONS

The 11 patients in this series showed that RFA combined with chemotherapy is a viable therapeutic choice for patients with cancer that has metastasized to the liver. New therapies are still needed.

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.

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.

Cryosurgery and radiofrequency ablation for unresectable colorectal liver metastases

AIMS

To report immediate local treatment efficacy and long-term results of cryosurgical ablation (CSA) and radiofrequency ablation (RFA) in patients with colorectal liver metastases not eligible for resection.

METHODS

Fifty-eight patients with unresectable colorectal liver metastases were included. Under ultrasound guidance, CSA or RFA were performed with or without concomitant resection. CT scanning and FDG-PET were used to determine local efficacy of the ablative procedure.

RESULTS

Median follow-up was 26 and 25 months for CSA and RFA, respectively. One and 2-year survival rates were 76 and 61% for CSA and 93 and 75% for RFA, respectively. In a lesion based analysis, the local recurrence rate was 9% after CSA and 6% after RFA. Complication rates were 30 and 11% after CSA and RFA, respectively, (p=0.052). In a subgroup analysis on 43 patients with 104 ablated lesions, CT scan immediate after treatment was not able to predict local treatment failure, whereas FDG-PET scan within 3 weeks after local ablative treatment predicted six of the seven local recurrences.

CONCLUSIONS

In patients with unresectable colorectal liver metastases, CSA and RFA can be used either alone or as an effective adjunct to resection in achieving complete tumour clearance of the liver. More widespread use of these techniques seems promising but requires further investigation in randomized trials comparing local ablative treatment with chemotherapy.

Interleukin-1β is prominent in the early pulmonary inflammatory response after hepatic injury

BACKGROUND

Acute lung injury and inflammation can occur after hepatic ischemia/reperfusion or cryoablation. The etiology of this response is uncertain although it involves NF-kappaB-mediated cytokine release from the liver.

METHODS

Inflammation-specific complementary DNA microarrays were utilized to evaluate cytokine upregulation in mouse lung at 4 hours after partial-volume hepatic cryoablation with a recirculating liquid N(2) probe. Hierarchical cluster analysis was performed to identify candidate genes. On the basis of these results, an enzyme-linked immunosorbent assay for interleukin-1beta (IL-1beta) was conducted on serum and pulmonary parenchymal specimens. The time course of IL-1beta transcriptional upregulation in the liver and lungs was evaluated by quantitative reverse transcription/real-time polymerase chain reaction.

RESULTS

Starting with a pool of 35 genes generated from normalization and variation filtration, unsupervised hierarchical clustering clearly distinguished lungs of hepatic cryo-injured mice from controls. Genes from the IL-1-family were prominent in the signature. IL-1beta was demonstrable in serum within 2 hours postinjury (218 +/- 89 pg/mL vs 0 at baseline, P = .01). In the lung, IL-1beta was more than 4-fold greater at 4 hours than at baseline. Real-time polymerase chain reaction showed a transcription peak of IL-1beta at 30 minutes in the liver, whereas expression in the lungs remained low until 60 minutes, then continued to increase through 4 hours.

CONCLUSIONS

Microarray analysis identified cytokines of the IL-1 family as central components of acute lung injury after hepatic cryoablation. IL-1beta levels increased in both serum and lung tissue over 4 hours after liver injury. Expression of IL-1beta peaked early in the injured liver remnant, followed by subsequent increases in the lungs. Targeted intervention against IL-1beta may ameliorate liver-mediated lung injury.

Percutaneous Radiofrequency Ablation of Hepatic Tumors: Postablation Syndrome

OBJECTIVE

Our objective was to define the spectrum and possible predictors of symptoms that occur in patients after percutaneous radiofrequency ablation of hepatic tumors.

SUBJECTS AND METHODS

We performed 50 consecutive percutaneous radiofrequency ablation sessions on 39 patients with a total of 89 liver tumors. All patients had pre- and postablation laboratory studies and CT or MRI scans. After treatment, patients were followed for 3 weeks with a standardized questionnaire to assess for postablation symptoms. Comparisons of the presence or absence of symptoms were made for the laboratory test values, liver volumes, and pre- and postablation tumor volumes.

RESULTS

Postablation symptoms occurred in 14 of 39 (36%) patients after 17 of 50 (34%) ablation sessions. Symptoms consisted of fever (16/17), malaise (12/17), chills (6/17), delayed pain (5/17), and nausea (2/17). On average, the symptoms presented 3 days after ablation and lasted 5 days. Statistically significant (p < 0.01) predictors of symptoms were tumor volumes > 50 cm3 (4.5 cm diameter), ablated tissue volumes > 150 cm3 (6.5 cm diameter), a difference between preablation tumor volume and the volume of tissue ablated > 125 cm3, or postablation aspartate aminotransferase levels > 350 IU/L.

CONCLUSION

Approximately one third of patients undergoing percutaneous radiofrequency ablation of hepatic tumors develop delayed, transient flulike symptoms that can be treated conservatively and are significantly related to the volume of tissue ablated. Familiarity with this postablation syndrome should facilitate appropriate management of affected patients.

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.

Surgical strategies for colorectal liver metastases

Colorectal cancer remains the second commonest cause of death from cancer in Western society. Nearly half of all patients will develop liver metastases and many will die with disease confined to the liver. The accepted modern definitions of resectability now mean that over twenty per cent of patients are now resectable (with operative mortality of >2%) with curative intent, and nearly one third will be alive, disease free, five years later. The use of additional techniques such as radiofrequency ablation may bring many more patients the possibility of long term survival. The introduction of new chemotherapy regimens, including those based on oxaliplatin may convert one third of non-resectable patients to resectability with curative intent. Therefore, in 2004 nearly one third of patients with disease confined to the liver can now look forward to possibly curative liver surgery.

Comparison of systemic responses of radiofrequency ablation, cryotherapy, and surgical resection in a porcine liver model

BACKGROUND

The degree of systemic response after hepatic radiofrequency ablation (RFA) has not been well investigated.

METHODS

An in vivo study was conducted on 23 domestic swine. Different hepatic procedures (RFA, cryotherapy, hepatic pedicle ligation, and hepatectomy) were performed on the medial lobe of the liver (30% of the liver volume). Systemic responses in terms of systemic inflammatory marker changes and end-organ functions were determined.

RESULTS

During the early postoperative period, the systemic inflammatory marker concentrations (tumor necrosis factor-alpha and interleukin-1beta) in the RFA group were significantly lower than in the cryotherapy group but significantly higher than in the control group. The corresponding concentrations in the hepatectomy group remained similar to those in the control group. The pattern of changes of serum inflammatory marker concentrations in the pedicle ligation group followed the pattern in the RFA group. The serum intracellular content concentrations (lactate dehydrogenase and urate) of the cryotherapy group peaked at 6 hours after operation, which was significantly later than in the other groups. Liver function, renal function, and coagulation profiles remained normal in the RFA group. However, the renal function deteriorated in the cryotherapy group on day 1. Both platelet count and activated clotting time showed significant derangement in the cryotherapy group compared with the control group. There was more severe interstitial pneumonitic change of the porcine lung after cryotherapy than after RFA.

CONCLUSIONS

The systemic responses of RFA were significantly less severe than those of cryotherapy in this porcine model. However, the increase in serum inflammatory markers and pneumonitis after RFA was substantial when compared with hepatectomy.

Cryotherapy for liver tumors: current status, perspectives, clinical results, and review of literature

Cryotherapy has gained importance as a locally ablative treatment option for patients with non-resectable liver tumors, especially metastases from colorectal cancer. We have used this technique since 1996 for the treatment of 77 patients with malignant liver tumors. Patient data was prospectively recorded and follow-up was until September 2002 or death. Fifty-five patients had colorectal cancer liver metastases, 16 metastases from other primaries and 6 had hepatoma. Forty patients had cryotherapy only and 37 had an additional liver resection. Morbidity and mortality were 22% and 1.3%, respectively. In 68% of patients with colorectal liver metastases and an elevated serum carcinoembryonic antigen-level preoperatively, it returned to the normal range following cryosurgery. For all 77 patients, median survival was 28 months with a 3- and 5-year-survival rate of 39% and 26%, respectively, and median survival was 29 months with a 3- and 5-year-survival rate of 44% and 26%, respectively, for the 55 patients with colorectal liver metastases. Local recurrence at the cryosite was observed in 13 of 65 patients (20%) with initially complete treatment. For cryotherapy to further establish as a treatment for malignant liver tumors in a time where many new local ablative techniques are developing, different goals need to be achieved. The trauma of the procedure and local treatment failure need to be minimized and survival results need to be optimized. Published studies and new possible fields of research regarding these goals are discussed.

The emergent role of focal liver ablation techniques in the treatment of primary and secondary liver tumours

Only 20% of patients with primary or secondary liver tumours are suitable for resection because of extrahepatic disease or the anatomical distribution of their disease. These patients could be treated by ablation of the tumour, thus preserving functioning liver. This study presents a detailed review of established and experimental ablation procedures. The relative merits of each technique will be discussed and clinical data regarding the efficacy of the techniques evaluated. A literature search from 1966 to 2003 was undertaken using Medline, Pubmed and Web of Science databases. Keywords were Hepatocellular carcinoma, liver metastases, percutaneous ethanol injection, cryotherapy, microwave coagulation therapy, radiofrequency ablation, interstitial laser photocoagulation, focused high-intensity ultrasound, hot saline injection, electrolysis and acetic acid injection. Ablative techniques offer a promising therapeutic modality to treat unresectable tumours. Large-scale randomised controlled trials are required before widespread acceptance of these techniques can occur.

Hepatic cryotherapy and regional chemotherapy with or without resection for liver metastases from colorectal carcinoma: how many are too many?

BACKGROUND

The number of hepatic metastases for which resection or ablation is appropriate remains controversial.

METHODS

A retrospective analysis was performed of prospectively collected data from patients with liver metastases from colorectal carcinoma who underwent hepatic cryotherapy and hepatic arterial chemotherapy (HAC) with or without undergoing resection. Patients routinely had preoperative bone scans, chest computed tomography (CT) scans, and abdominal angio-CT scans. Positron emission tomography scans were unavailable. All patients were followed until June 2002 or until death occurred. Kaplan-Meier and Cox regression methods were used to evaluate the impact of 17 potentially prognostic factors on survival.

RESULTS

One hundred seventy-two patients who underwent hepatic cryotherapy and HAC with or without undergoing liver resection for in situ eradication of metastases formed the basis of this report. One patient (0.6%) died postoperatively from myocardial infarction. The morbidity rate was 27.9%. The median survival was 28 months (range, 0-98 months). The factors age < or = 50 years, well-differentiated or moderately differentiated primary tumor, small cryolesions (<3.5 cm), complete eradication of extrahepatic metastases at cryotherapy, and low preoperative carcinoembryonic antigen (CEA) levels were associated independently with a favorable outcome. In addition, a univariate analysis showed that the absence of untreated extrahepatic disease at laparotomy, postoperative CEA normalization, and a large decline in CEA levels were significant statistically. The number of lesions was not prognostic. One hundred forty-six patients (84.9%) who underwent a complete operation had 1-year, 2-year, 3-year, 4-year, and 5-year survival rates of 89%, 65%, 41%, 24%, and 19%, respectively. The median survival of patients with 1 metastasis, 2 metastases, 3 metastases, 4 metastases, 5 metastases, 6 or 7 metastases, and 8-12 metastases were 32 months, 29 months, 30 months, 31 months, 27 months, 37 months, and 21 months, respectively (P=0.7859). Twenty-five patients had 6 or 7 lesions, and their 5-year survival rate was 25%.

CONCLUSIONS

When all colorectal hepatic lesions were eradicated, the numbers of hepatic metastases were not prognostic of survival in patients with liver metastases from colorectal carcinoma.

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.

Interstitial ablative techniques for hepatic tumours

BACKGROUND

Most patients with liver tumours are not suitable for surgery but interstitial ablative techniques may control disease progression and improve survival rates.

METHODS

A review was undertaken using Medline of all reported studies of cryoablation, radiofrequency ablation, microwave ablation, interstitial laser photocoagulation, high-intensity focused ultrasound and ethanol ablation of primary liver tumours and hepatic metastases.

RESULTS

Although there are no randomized clinical trials, cryoablation, thermal ablation and ethanol ablation have all been shown to be associated with improved palliation in patients with primary and secondary liver cancer. The techniques can be undertaken safely with minimal morbidity and mortality.

CONCLUSION

Although surgical resection remains the first line of treatment for selected patients with primary and secondary liver malignancies, interstitial ablative techniques are promising therapies for patients not suitable for hepatic resection or as an adjunct to liver surgery.

[High intensity focused ultrasonic destruction of hepatic parenchyma]

OBJECTIVE

High intensity focused ultrasound (HIFU) is an effective and precise method of focal tumoral destruction since it is associated with imagery. This method is widespread for the endorectal treatment of prostatic adenocarcinomas. HIFU seem appropriate for the treatment of liver tumors but its use needs to be experimentally tested in vivo. The aim of the work is to study the feasibility, tolerance and effectiveness of the destruction of porcine liver by HIFU.

MATERIAL AND METHODS

Ten pigs had liver destruction by HIFU after coeliotomy. Four to 5 2,3 cm(3) HIFU lesions were performed per animal under ultrasonographic control. The study included biological surveillance and an autopsy was performed 4 to 24 hours later for histological examination of the liver.

RESULTS

The destruction of the liver was feasible in all cases and the 4 lobes of the liver could be treated. The general and biological tolerance of the procedure was excellent. Ultrasonographic features of the HIFU lesions were defined. The histological examination of the lesions showed well-circumscribed necrosis areas associated with cavitation or histological deficiencies of various degrees.

CONCLUSION

This work demonstrated that liver destruction by HIFU is a feasible and effective method with low morbidity. A long-term experimental study is necessary before comtemplating its clinical use.

The histological features of microwave coagulation therapy: an assessment of a new applicator design

Microwave ablation of tumours within the liver may become an adjunct or alternative to resection in patients with primary or secondary cancers. This technique combines the benefits of a large, localized coagulative effect with a single insertion of the applicator, in a significantly shorter time than comparable treatments. A new range of microwave applicators were developed and tested in animal models and both ex-vivo and in-vivo specimens of human liver at resection. At laparotomy, the applicator tip was inserted into normal liver parenchyma and tumours, with each specimen subjected to irradiation for 180 s or more and at varying power outputs. On sectioning an area of spherical blanching was observed around the applicator cavity. Microscopically a zone of coagulative necrosis was seen adjacent to the site of probe insertion. Damage to blood vessels and bile ducts occurred distal to the probe cavity suggesting the passage of heated fluid, a finding that was diminished by temporary occlusion of the hepatic vasculature (a Pringle manoeuvre). Ultra-structural damage was confirmed within the burn zone and selected liver enzymes were shown to be functioning beyond this region. We suggest this indicates the surrounding liver parenchyma is functioning normally and therefore the volume of microwave-induced damage is controllable. We are confident that the new applicator design will allow the effective treatment of larger tumours in a safe and controlled manner with a single application of energy.

Management of colorectal liver metastases

Hepatic metastases occur in 60% of patients following resection for colorectal cancer. Liver resection is the only curative option, with one third of resected patients alive at five years. In those developing recurrence in the liver following resection, further liver surgery may be curative, with similar 5 years survival rates of about 30%. Until recently surgery was feasible in only 15-25% of patients with colorectal liver metastases. New strategies, such as downstaging chemotherapy, portal vein embolization and two-stage hepatectomy, may increase the resectability rate by 15%. Earlier detection of liver metastases would increase resectability, although good follow-up trials are lacking. Once suspected, colorectal liver metastases are staged by spiral CT, CT portography and MRI, which have similar overall accuracies. Mortality following liver resection is less than 5% in major centres, with a morbidity rate of 20% to 50%. Prognostic scoring systems can be used to predict the likely cure rate with resection. Pulmonary metastases occur in 10-25% of patients with resected colorectal cancer, but are limited to the lung in only 2% of cases. In these selected cases surgery provides long-term survival in 20-40%, and repeat lung resection has shown similar rates. For patients with unresectable disease, chemotherapy and ablation techniques have been demonstrated to prolong survival, although chemotherapy alone has been shown to improve quality of life.

Combination of neoadjuvant chemotherapy with cryotherapy and surgical resection for the treatment of unresectable liver metastases from colorectal carcinoma

BACKGROUND

This retrospective study was conducted to assess the safety, efficacy, and long-term results of neoadjuvant chemotherapy and cryotherapy as additional means for eradicating liver metastases from colorectal carcinoma when curative treatment was not possible by resection alone.

METHODS

Between January 1996 and December 1997, 131 patients with unresectable liver metastases were referred to our department and received chemotherapy. After 3-6 months of chemotherapy, curative surgery of liver metastases was considered possible in 57 patients, either by resection alone in 33 patients (25%) or cryotherapy associated with resection in 24 patients (18%). Characteristics and survival of patients in the cryotherapy plus resection group were compared with those of the 33 patients in the resection group.

RESULTS

All patients in the resection group had partial response to neoadjuvant chemotherapy. In the cryotherapy plus resection group, neoadjuvant chemotherapy resulted in 13 partial responses, 9 stable diseases, and 2 disease progressions. The rate of postoperative complications in the entire series was 14%. No major difference was seen between the two groups. After a median follow-up of 48 months, the median survival time was 39 months. The survival rates at 1, 3, and 4 years were similar in both groups: 94, 58, and 37% in the resection group and 92, 50, and 36% in the cryotherapy plus resection group, respectively.

CONCLUSIONS

The combination of neoadjuvant chemotherapy, cryotherapy, and liver resection constitutes a promising treatment strategy for patients with extremely advanced metastatic liver involvement. Patients having more than four liver metastases from a colorectal carcinoma or patients with a poor liver reserve due to previous resection should be screened carefully to determine whether they could be candidates for this procedure.

Cryotherapeutic ablation of liver tumours

BACKGROUND

This paper reports a 7-year experience of cryoablation for colorectal and non-colorectal liver metastases.

METHODS

A retrospective review was undertaken of patients treated in two adjacent UK centres in the north-west of England.

RESULTS

Over a 7-year period (1993-2000), 57 patients underwent cryotherapy for malignant hepatic tumours (41 colorectal, 16 non-colorectal). In the patients with colorectal metastases, preoperative carcinoembryonic antigen (CEA) levels fell significantly, from a mean of 444.1 to 6.22 micro g/l (P = 0.002). One patient died, two developed cryoshock and six had cardiorespiratory complications. All patients with colorectal metastases subsequently received 5-fluorouracil-based chemotherapy. The remaining 16 patients with non-colorectal tumours (seven neuroendocrine metastases, five hepatocellular carcinomas, three sarcomas, one cholangiocarcinoma) all received cryotherapy alone, with no major complications. The median survival for patients with non-colorectal metastases was 37 months, compared with 22 months for those with colorectal metastases (P = 0.005).

CONCLUSION

Hepatic cryotherapy is effective and safe, as demonstrated by the significant reduction in postoperative CEA concentration and the low risk of complications. However, this initial short-term success was not reflected in 5-year survival rates. Cryotherapy for non-colorectal metastases had a greater long-term survival benefit and is a useful means of controlling symptoms.

Large volume hepatic freezing: association with significant release of the cytokines interleukin-6 and tumor necrosis factor a in a rat model

Although cryotherapy of liver tumors is generally considered a safe procedure, a syndrome of coagulopathy and fatal multiorgan failure has been observed in some patients and is called the cryoshock phenomenon. Our aim was to establish an animal model of this phenomenon and examine the effects of the basic parameters of freezing or cryotherapy on it. A group of 75 female Sprague-Dawley rats were allocated randomly to five groups: (1) sham laparotomy (n = 15); (2) small (25% liver volume) single freeze (n = 15); (3) small (25% liver volume) double freeze (n = 15); (4) large (50% liver volume) single freeze (n = 15); (5) large (50% liver volume) double freeze (n = 15). Blood samples were collected at different postoperative times, and organs were harvested for histopathology. There was a significant release of tumor necrosis factor-a (TNFa) and interleukin 6 (IL-6) following hepatic freezing, which was greatest in group 5. Postoperative serum cytokine levels were significantly associated with hepatocellular injury, as measured by postoperative serum aspartate transaminase (AST) concentrations. Severe hemoglobinuria and renal injury, as demonstrated by the serum creatinine level and the glomerular neutrophil count, were observed and were greatest in group 5. Hepatic cryosurgery is associated with release of IL-6 and TNFa and renal injury in a rat model. It is likely that the cryoshock phenomenon is another form of the systemic inflammatory response syndrome. Based on the results of this study, it is possibly mediated by cytokines released from the frozen liver tissue. We therefore caution against cryotherapy of large tumor volumes.

Experimental study of large-volume microwave ablation in the liver

BACKGROUND

Microwave coagulation therapy is useful in the destruction of small, irresectable liver tumours of primary and secondary origin. Unfortunately, the small lesion size produced by currently available equipment makes it difficult and time consuming completely to ablate lesions larger than 3 cm in diameter. A microwave system capable of producing large-volume ablations in very short periods of time has been developed. Using a large-animal model the ability of the equipment to produce large-volume lesions in a safe, predictable and dose-dependent manner was tested.

METHODS

Fourteen large white pigs were anaesthetized and underwent multiple microwave treatments. The animals were killed at different timepoints to investigate lesion size and evolution.

RESULTS

The microwave system was able to generate large-volume ablations of up to 6.5 cm in diameter in a controlled and dose-dependent manner.

CONCLUSION

This novel microwave system allows the ablation of large volumes of liver tissue in a short period of time. The ability to produce lesions reproducibly and safely highlights the potential of this system in the future treatment of irresectable liver tumours.

Regional therapy of hepatic metastases

In conclusion, there are a variety of treatment approaches used by surgeons, interventional radiologists, and medical oncologists to treat metastatic cancer distributed throughout the liver. One conclusion is that the number of different techniques suggests that no single treatment has been uniformly successful to date. A second conclusion is that the number of techniques applied argues for the importance of this as a clinical problem in oncology today. The number of patients with metastatic disease to the liver and the potential for long-term survival if that disease can be controlled will lead to further combinations and refinements of these techniques in future clinical trials.

Electrolytic ablation as an adjunct to liver resection: experimental studies of predictability and safety

BACKGROUND

Combined liver resection and local ablation may offer the only chance of cure to patients with liver metastases who are presently deemed unresectable because of a single awkwardly placed metastasis. By definition, such a metastasis is often close to a major vein. An ablative technique is needed that is both predictable and safe in such a circumstance.

METHODS

Electrolytic liver lesions were created in 21 pigs using platinum electrodes, connected to a direct current generator. Both electrolytic 'dose' and electrode separation were varied to produce different sized lesions. The 'dose' was correlated with the volume of necrosis and any vascular damage was determined histologically.

RESULTS

There was a significant (P < 0.001) correlation between the electrolytic 'dose' and the volume of liver necrosis. For a given 'dose' the volume of necrosis was less when the electrodes were together, rather than separated. Liver enzymes were only transiently deranged. There were no significant vascular injuries.

CONCLUSION

Predictable and reproducible necrosis is produced by electrolysis in the pig liver. The treatment appears to cause little or no damage to immediately adjacent liver or major vascular structures and, when combined with resection, may offer the chance of a cure to many patients who are currently unresectable.

Resection and local therapy for liver metastases

In 30-50% of patients the liver is a preferred site of distant disease for many malignant tumours. Due to the high incidence, most of the available data relate to metastases arising from colorectal primaries. Surgical resection is at present the only treatment offering potential cure. The achievable 5-year survival rate is 30%. However, only 10-15% of patients with colorectal liver metastases can undergo potentially curative liver resection. Therefore, accurate staging is an important prerequisite in selecting patients who would benefit from surgery. Recurrence of hepatic metastases after potentially curative resection occurs in up to 60% of the cases. Results demonstrate that re-resection of liver metastases can provide long-term survival rates in a carefully selected group of patients without extrahepatic disease. Because of the high rate of recurrences following an apparently curative resection several authors investigated the use of adjuvant chemotherapy (systemic, intraportal, and hepatic arterial infusion). Until recently none had shown effectiveness. Pre-operative chemotherapy seems to be a promising approach in patients with liver metastases initially considered unsuitable for radical surgery. Recently, neoadjuvant chemotherapy has been proposed as an alternative approach to conventional surgery as initial management with the aim of improving the results in resectable liver metastases. Interventional strategies (ethanol injection, cryosurgery, laser-induced thermotherapy, radio-frequency ablation) and combined modalities (surgical/interventional) are additive methods which may help to improve treatment results in the future.

Cryoablation of unresectable pancreatic cancer

BACKGROUND

Most patients with pancreatic cancer are not candidates for curative resection. The goal of this study was to evaluate the safety of an intraoperative ultrasound-guided cryosurgical procedure in a phase I study of unresectable pancreatic cancer.

METHODS

From March 1995 to March 1999, 10 cryosurgeries using intraoperative ultrasound were performed on 9 patients with unresectable cancers at laparotomy. Four patients had a concurrent gastrojejunostomy, 2 had a chemical splanchnicectomy, and 1 underwent a concurrent hepatic cryosurgical procedure.

RESULTS

There was no intraoperative morbidity or mortality. No patients developed postoperative pancreatitis or fistula. All patients had good pain control postoperatively and were tolerating a regular diet at the time of discharge. Pain control at discharge was achieved with an oral formulation (4/9), transdermal patch (3/9), no pain medication (1/9), and intravenous patient controlled analgesia (1/9).

CONCLUSIONS

Ultrasound-guided cryoablation for unresectable pancreatic cancer appears safe and may contribute to improved postoperative pain control. Future studies to determine its therapeutic role in the management of unresectable pancreatic cancer are indicated.

Cryotherapy in the treatment of liver metastases from colorectal cancer

Although hepatic resection remains the treatment of choice for metastatic disease to the liver from colorectal cancer, the procedure is only possible for approximately 10% of patients. Ninety percent of patients with liver metastases ultimately die of liver failure. Thus, attention has turned to other, locoregional techniques that may be used alone or in conjunction with resection to increase the eligibility for some type of surgical, potentially curative treatment. One such option is cryotherapy. This review provides technical, physiologic, and outcome information regarding this technique. Semin Oncol 29:183-191.