Treatment of hepatic metastases by cryotherapy and regional cytotoxic perfusion

Meta-analysis of transarterial chemoembolization combined with cryoablation vs transarterial chemoembolization alone for ≥ 5 cm hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) ranks sixth globally in cancer incidence and third in mortality rates. Unfortunately, over 70% of HCC patients forego the opportunity for curative surgery or liver transplantation due to inadequate physical examinations, poor physical condition, and limited organ availability upon diagnosis. Clinical guidelines endorse transarterial chemoembolization (TACE) as the frontline treatment for intermediate to advanced-stage HCC. Cryoablation (CRA) is an emerging local ablative therapy increasingly used in HCC management. Recent studies suggest that combining CRA with TACE offers complementary and synergistic effects, potentially improving long-term survival rates. However, the superiority of combined TACE + CRA therapy over TACE alone for HCC lesions equal to or exceeding 5 cm requires further investigation.

AIM

To compare the efficacy and safety of TACE combined with CRA vs TACE alone in the treatment of HCC with a diameter of ≥ 5 cm.

METHODS

PubMed, EMBASE, Cochrane Library, CNKI, Wanfang, and VIP databases were searched to retrieve all relevant studies on TACE and CRA up to July 2022. Meta-analysis was performed using RevMan 5.3 software.

RESULTS

After screening according to the inclusion and exclusion criteria, 6 articles were included, including 2 randomized controlled trials and 4 nonrandomized controlled trials, with a total of 575 patients included in the meta-analysis. The results showed that the objective response rate [odds ratio (OR) = 2.56, 95% confidence interval (CI):1.66-3.96, P < 0.0001), disease control rate (OR = 3.03, 95%CI: 1.88-4.89, P < 0.00001), 1-year survival rate (OR = 3.79, 95%CI: 2.50-5.76, P < 0.00001), 2-year survival rate (OR = 2.34, 95%CI: 1.43-3.85, P = 0.0008), and 3-year survival rate (OR = 3.34, 95%CI: 1.61-6.94, P = 0.001) were all superior to those of the control group; the postoperative decrease in alpha-fetoprotein value (OR = 295.53, 95%CI: 250.22-340.85, P < 0.0001), the postoperative increase in CD4 value (OR = 10.59, 95%CI: 8.78-12.40, P < 0.00001), and the postoperative decrease in CD8 value (OR = 6.47, 95%CI: 4.44-8.50, P < 0.00001) were also significantly higher than those in the TACE-alone treatment group.

CONCLUSION

Compared with TACE-alone treatment, TACE + CRA combined treatment not only improves the immune function of HCC patients with a diameter of ≥ 5 cm, but also enhances the therapeutic efficacy and long-term survival rate, without increasing the risk of complications. Therefore, TACE + CRA combined treatment may be a more recommended treatment for patients with HCC with a diameter of ≥ 5 cm.

Contrast-Enhanced Ultrasound Tumor Therapy With Abdominal Imaging Transducer

A diagnostic ultrasound machine add-on module (AOM) was created to enable an off-the-shelf abdominal imaging transducer to perform contrast-enhanced therapeutic ultrasound. The AOM creates plane-wave ultrasound through an abdominal imaging transducer targeting intravascular microbubbles within tumors. This therapeutic antivascular ultrasound (AVUS) causes heating and cavitation effects that destroy tumor vasculature and starves it of nutrients. The AOM can switch between therapeutic and imaging modes for monitoring AVUS treatment. The therapeutic capability of the AOM was validated in murine hepatocellular carcinomas (HCC) grown in adult mice. Contrast-enhanced ultrasound imaging performed before and after the therapeutic treatment evaluated the AVUS response to the treatment. The peak enhancement (PE), perfusion index (PI), and area under the curve (AUC) were measured for the control and AOM treatment groups. The AOM group showed a substantial decrease in these parameters compared to the control group. The difference between the pre- and post-therapy was significant, (p < 0.001) for the AOM group and not significant (p > 0.5) for the control group. Tumor temperatures increased markedly for the AOM group with a thermal dose (CEM43) of 124.8 (±2.5). Histochemical analysis of the excised HCC samples revealed several hemorrhagic pools in tumors from the AOM group, absent in the tumors of the control group. These results demonstrate the theranostic potential of the AOM to induce and monitor vascular disruption within murine tumors.

Challenges Facing Percutaneous Ablation in the Treatment of Hepatocellular Carcinoma: Extension of Ablation Criteria

As an emerging minimally invasive treatment method, percutaneous ablation is more and more widely used in the treatment of liver tumors. It has been recommended by guidelines for diagnosis and treatment of hepatocellular carcinoma (HCC) as a curative treatment alongside surgical resection and liver transplantation. In recent years, with the continuous advancement and innovation of percutaneous ablation technologies, their clinical efficacy and safety have been significantly improved, which has led to the expanded application of percutaneous ablation in the treatment of HCC—more and more patients who were previously considered unsuitable for ablation therapies are now being treated with percutaneous ablation. Obviously, percutaneous ablation can reduce the risk of treatment changes from curative strategies to palliative strategies. Based on clinical practice experience, this review enumerates the advantages and disadvantages of different ablative modalities and summarizes the existing combinations of ablation techniques, thus will help clinicians choose the most appropriate ablative modality for each patient and will provide scientific guidance for improving prognosis and making evidence-based treatment decisions. In addition, we point out the challenges and future prospects of the ablation therapies, thereby providing direction for future research.

Thermal ablation versus surgical resection for localized hepatocellular carcinoma: a population study using the SEER database

AIM

To compare overall survival (OS) and liver cancer-specific survival (LCSS) in patients with localized hepatocellular carcinoma treated with surgical resection (SR) or thermal ablation (TA) using the Surveillance, Epidemiology and End Results database.

MATERIALS & METHODS

Kaplan-Meier, competing risk and Cox regression analyses were performed after identifying patients. Propensity score matching was then applied.

RESULTS

There was significantly better OS in the SR group and significantly lower probability of LCSS in the TA group. After matching, there was significantly longer OS in the SR group and a lower probability of LCSS in the TA group.

CONCLUSION

SR offered a significant survival benefit over TA for localized hepatocellular carcinoma.

Lung metastases after liver resection or cryotherapy for hepatic metastasis from colorectal cancer--there is a difference!

BACKGROUND

The most common site of colorectal extra-abdominal metastases is the lung. The relative risk of lung metastases after resection and cryotherapy has not previously been compared.

METHODS

All patients underwent an extensive preoperative staging including clinical examination, abdominal computed tomography (CT) and abdominal angio-CT to assess their hepatic disease. Two groups of patients were compared in this study (hepatic resection alone and hepatic cryotherapy with or without resection). A retrospective analysis of prospectively collected data was performed to assess the incidence and disease-free interval of pulmonary metastasis after surgical treatment of colorectal liver metastasis.

RESULTS

This paper clearly shows two differences regarding pulmonary metastases between patients treated with resection only and cryotherapy with or without resection. Among the 10 clinical variables, cryotherapy had the greatest correlation with pulmonary metastases (p=0.004). A patient who undergoes hepatic resection only has a probability of 35% for developing pulmonary recurrence, compared with 51% following cryotherapy. Cryotherapy was also independently associated with shorter pulmonary disease-free interval (p=0.036).

CONCLUSION

There clearly is a higher risk of pulmonary metastasis after cryotherapy than after resection, whether this is related to selection of patients or a direct deleterious procedural effect requires more study.

Phase I trial of systemic oxaliplatin combination chemotherapy with hepatic arterial infusion in patients with unresectable liver metastases from colorectal cancer

PURPOSE

To determine the maximum-tolerated dose (MTD) of concurrent systemic oxaliplatin (Oxal) combinations plus hepatic arterial infusion (HAI) in patients with unresectable hepatic metastases from colorectal cancer.

PATIENTS AND METHODS

Thirty-six patients (89% previously treated) with unresectable liver metastases were treated with concurrent HAI and systemic Oxal plus irinotecan (CPT-11; group A) or Oxal, fluorouracil (FU), and leucovorin (LV; group B). Systemic chemotherapy was administered every 2 weeks concurrent with 2 weeks of HAI floxuridine (FUDR) and dexamethasone (Dex) every 28 days.

RESULTS

The MTD for patients in group A was Oxal 100 mg/m(2), CPT-11 150 mg/m(2), and FUDR 0.12 mg/kg x 30 mL divided by pump flow rate. The MTD for group B was Oxal 100 mg/m(2), LV 400 mg/m(2), and FU 1,400 mg/m(2) by continuous infusion over 48 hours, with the same FUDR dose as in group A. Grade 3 or 4 toxicities in groups A and B included diarrhea (24% and 20%), neutropenia (10% and 7%), neurotoxicity (24% and 20%), and bilirubin more than 3 mg/mL (5% and 7%, respectively). The complete and partial response rate totaled 90% for group A and 87% for group B. Median survival time was 36 and 22 months for groups A and B, respectively. Seven patients in group A were ultimately able to undergo liver resection.

CONCLUSION

Combination therapy with HAI FUDR and Dex plus systemic Oxal combinations may be safely administered to patients with colorectal cancer. The high response rate (88%) and the possibility of conversion to resectability, despite disease progression on prior systemic regimens, suggest that these combinations should be evaluated in larger studies as first- or second-line therapy in patients with hepatic metastases from colorectal cancer.

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.

Rectal cancer

Rectal cancer is an important tumour from an epidemiological point of view and represents the benchmark for an optimal use of integrated treatments (surgery, radiotherapy and chemotherapy) in the oncological practice. Performing radio-chemotherapy (best if preoperatively), medical and radiation oncologists are now able to increase survival, to decrease the occurrence of pelvic recurrence and to ameliorate the quality of life of patients. Updated recommendations for the management of these patients are here reported.

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.

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.

Establishment of a nude mouse model of hepatic metastasis for evaluation of targeted retroviral gene delivery

BACKGROUND AND OBJECTIVES

The goal of this study was to establish a reproducible nude mouse model of liver metastasis and investigate the potential of deploying targeted injectable retroviral vectors for metastatic gastrointestinal cancer.

METHODS

Human cancer cells were injected into the portal vein via an indwelling catheter. The animals were sacrificed at specified time intervals, and the number of tumor nodules was counted in histologic sections of harvested livers. A group of animals received either an extracellular matrix-targeted or a nontargeted retroviral vector bearing a beta-galactosidase gene by portal vein infusion.

RESULTS

The number of tumor nodules increased progressively over time at </=50 days post-infusion (r = 0.81; P < 0.0001). Transduction of tumor nodules was observed in the animals that received a matrix-targeted, but not a nontargeted, vector.

CONCLUSIONS

We have established a reproducible nude mouse model of liver metastasis, and demonstrated the feasibility of gene delivery to metastatic tumor nodules in vivo by portal vein infusions of a matrix-targeted retroviral vector.

Retroperitoneal laparoscopic cryoablation of small renal tumors: intermediate results

OBJECTIVES

To present our experience with laparoscopic renal cryoablation with up to 3 years of follow-up. Laparoscopic renal cryoablation remains a viable option for the treatment of small peripheral renal masses in patients with significant comorbidities. Although partial nephrectomy has been shown to be a safe and reliable method of renal parenchymal preservation, laparoscopic cryoablation still requires longer term data to prove its efficacy.

METHODS

Twenty patients with small renal masses (1.4 to 4.5 cm) underwent laparoscopic renal cryosurgery at our institution. A retroperitoneal laparoscopic approach was used to expose the kidney. Intraoperative ultrasound guidance was used to localize the lesions and monitor iceball formation. A double-freeze technique was used. Needle biopsies of solid masses were performed intraoperatively.

RESULTS

Renal biopsies revealed renal cell carcinoma in 11 of the 20 patients. Of these 11 patients, none had evidence of recurrent disease at last follow-up, and follow-up scans showed no enhancement of any lesions. Of the 8 patients with follow-up of 2 years or greater, 4 had complete resolution of the renal lesions. The remainder had lesions that were reduced and stable in size. Complications included surgical re-exploration to evaluate pancreatic injury in 1 patient and failure to ablate a lesion in another.

CONCLUSIONS

Laparoscopic renal cryoablation appears to be an effective tool for ablation of small renal lesions. A moderate length of follow-up continues to demonstrate efficacy because no patients had growth of treated pathologic lesions or developed metastasis to date. Continued maturation of data is necessary to determine the long-term efficacy.

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.

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.

Cryosurgery of Close or Positive Margins after Hepatic Resection for Primary and Metastatic Hepatobiliary Malignancies

Obtaining a one-centimeter negative margin is an important factor in preventing disease recurrence after surgery for hepatic tumors. Cryotherapy of the resected edge has been used to achieve optimal margin clearance in cases in which the alternative would be an extended high-risk liver resection. The effect of this technique on margin recurrence was examined. Between 1994 and 2001 a total of 56 patients underwent cryosurgery with or without resection for primary and metastatic hepatobiliary malignancies. A 5-cm cryotherapy lollipop probe was used to ablate surgical margins less than one centimeter in 13 of these patients. There were seven colorectal metastases, three hepatocellular carcinomas, and three gallbladder carcinomas. The median size of the colorectal and hepatocellular lesions was 3 cm (range 2–14 cm), and all gallbladder primaries were T2 tumors. All tumors except three were located centrally in the liver requiring cryoablation of margins at segments 4, 5, and 8. Most patients had one site frozen (n = 9) with a median target temperature of -190°C and a median of two freeze-thaw cycles. Final pathological analysis of the resected specimens revealed nine close (<1 cm) and four positive margins. With a median follow-up of 16 months seven patients are alive with no evidence of disease and six have developed recurrences with three of them dying of their disease. Only one (8%) of the initial recurrences was at the cryoablated margin. Cryosurgery of the resection edge facilitates liver resection for malignant tumors when margins are close or positive. Because disease recurrence at the cryoablated margin is low this technique may allow more patients to undergo effective surgical treatment of their hepatobiliary cancers.

Electrolysis and other local ablative treatments for non-resectable colorectal liver metastases

The present paper is a review of the current ablative treatment options for the treatment of colorectal liver metastases. Cryotherapy, microwave coagulation therapy, radiofrequency ablation and laser-induced thermotherapy are discussed. Electrolysis, a novel non-thermal ablative treatment, is described. Potential benefits of electrolysis include the apparent ability to safely and effectively treat lesions abutting major hepatic structures and the lack of a systemic inflammatory reaction following electrolytic ablation. Further studies in animals and humans are needed to confirm this potential and to further refine the methods of electrolytic treatment of colorectal liver metastases.

Metastatic liver tumors

The liver is a common site of metastasis from a variety of tumors. In many cases, liver resection for metastatic cancer provides the only chance for a cure and can be performed with less than 5% mortality and acceptable morbidity. The 5-year survival following liver resection for colorectal metastasis is reported in many large series to be 25% to 37%. The data regarding liver resection for other metastatic tumor types are less clear. However, resection for selected tumors, such as neuroendocrine and renal cell, can provide durable palliation and/or cure. We will review important prognostic factors used to guide the selection of patients for resection of metastatic disease and make recommendations for imaging studies and follow-up routines. The role of adjuvant regional and systemic chemotherapy for resectable metastatic disease is also discussed. Methods for ablating unresectable metastatic tumors may prove to be useful adjuncts to current therapies.

Treatment of recurrent colorectal liver metastases by interstitial laser photocoagulation

BACKGROUND

Hepatic resection improves survival in selected patients with colorectal liver metastases. The treatment of recurrent hepatic metastases after resection is controversial. Interstitial laser photocoagulation, performed under local anaesthesia, offers a minimally invasive option to repeat resection. The first series of patients with recurrent colorectal liver metastases treated with photo- coagulation is reported.

METHODS

Nineteen patients (five women and 14 men, median age 57 (range 44-71) years) who developed recurrent colorectal liver metastases after hepatectomy (five with bilateral disease) were treated with photocoagulation between 1993 and 1997. Fifteen patients also received chemotherapy (14 systemic, one hepatic arterial) before photocoagulation.

RESULTS

There were no major complications or deaths related to the treatment. Six patients developed minor complications related to the procedure but did not require any form of intervention. Median survival from commencement of photocoagulation was 16 (range 4-36) months.

CONCLUSION

Photocoagulation is a safe, minimally invasive therapy that may be used as an adjunct to chemotherapy and repeat resection in the treatment of recurrent colorectal liver metastases, and may lead to improved survival.

Complete shutdown of microvascular perfusion upon hepatic cryothermia is critically dependent on local tissue temperature

Since microvascular dysfunction with complete circulatory arrest and, thus, prolongation of tissue ischaemia is considered a potential mechanism for cell necrosis following hepatic cryosurgery, we determined the temperature necessary for induction of complete nutritive perfusion failure in cryothermia-treated rat livers. After localization of the cryoprobe with seven thermocouples and application of a single or double freeze-thaw cycle, in vivo fluorescence microscopy of the cryoinjured left lobe was performed over a 2-h period using a computer-controlled stepping motor, which guaranteed analysis of the identical liver tissue segments with exact allocation of the thermocouples and thus determination of tissue temperature. Cryothermia resulted in a central non-perfused part of injury, surrounded by a heterogeneously perfused peripheral zone. The non-perfused area after single and double freezing continuously increased over the first 90-min period due to a successive shutdown of perfusion within the peripheral border zone. Analysis of the thermocouples' temperature at the end of freezing revealed the 0 degrees C-front at 11.7 mm (single freeze-thaw cycle) and 12.1 mm (double freeze-thaw cycle) distant from the centre of the cryoprobe, which exactly corresponds with the initial (30 min) expansion of the area with nutritive perfusion failure. The increased non-perfused tissue area at 2 h conformed a critical border temperature between 8.29 +/- 1.63 degrees C and 9.07 +/- 0.24 degrees C. From these findings, we conclude that freezing of liver tissue to temperatures of at least < 0 degrees C causes complete/irreversible perfusion failure, which consequently will result in cell death and tissue necrosis, and may thus be supposed as a prerequisite for the safe and successful application of cryosurgery in hepatic tumour ablation.

Intraoperative radiofrequency ablation or cryoablation for hepatic malignancies

BACKGROUND

The majority of patients with primary or metastatic malignancies confined to the liver are not candidates for resection because of tumor size, location, multifocality, or inadequate functional hepatic reserve. Cryoablation has become a common treatment in select groups of these patients with unresectable liver tumors. However, hepatic cryoablation is associated with significant morbidity. Radiofrequency ablation (RFA) is a technique that destroys liver tumors in situ by localized application of heat to produce coagulative necrosis. In this study, we compared the complication and early local recurrence rates in patients with unresectable malignant liver tumors treated with either cryoablation or RFA.

PATIENTS AND METHODS

Patients with hepatic malignancies were entered into two consecutive prospective, nonrandomized trials. The liver tumors were treated intraoperatively with cryoablation or RFA; intraoperative ultrasonography was used to guide placement of cryoprobes or RFA needles. All patients were followed up postoperatively to assess complications, treatment response, and local recurrence of malignant disease.

RESULTS

Cryoablation was performed on 88 tumors in 54 patients, and RFA was used to treat 138 tumors in 92 patients. Treatment-related complications, including 1 postoperative death, occurred in 22 of the 54 patients treated with cryoablation (40.7% complication rate). In contrast, there were no treatment-related deaths and only 3 complications after RFA (3.3% complication rate, P<0.001). With a median follow-up of 15 months in both patient groups, tumor has recurred in 3 of 138 lesions treated with RFA (2.2%), versus 12 of 88 tumors treated with cryoablation (13.6%, P<0.01).

CONCLUSIONS

RFA is a safe, well-tolerated treatment for patients with unresectable hepatic malignancies. This study indicates that (1) complications occur much less frequently following RFA of liver tumors compared with cryoablation of liver tumors, and (2) early local tumor recurrence is infrequent following RFA.

Surgical treatment of malignant liver tumours

Surgical resection is the mainstay of treatment for malignant liver tumours and offers the only chance of cure. Advances in radiological imaging, surgical technique and peri-operative management have enabled liver resection to be performed safely. Partial hepatectomy is indicated for the treatment of hepatocellular carcinoma and hepatic metastases from colorectal cancer. In addition, it may be utilized for selected patients with liver metastases from other primary tumours. Total hepatectomy with transplantation may be of benefit in some patients with unresectable neuroendocrine metastases or small hepatocellular carcinomas. The role of cryosurgery has not been precisely defined, and it needs to be compared with other palliative therapies such as ethanol injection and hepatic artery embolization.

Epi-illumination fluorescent light microscopy for the in vivo study of rat hepatic microvascular response to cryothermia

To elucidate the hepatic microvascular response to cryothermia, we studied the liver microcirculation of Sprague-Dawley rats after one and two 4-minute freeze-thaw cycles using intravital fluorescence microscopy. Irrespective of the number of freeze-thaw cycles applied, the nature of hepatic microvascular injury was characterized by complete stasis of sinusoidal blood flow within the central part of the cryolesions and heterogeneous sinusoidal perfusion in a critically perfused border zone located at the periphery of the lesions. Analysis over time (2 hours) revealed a successive shutdown of sinusoidal perfusion within this critically perfused border zone, which was caused by intravascularly lodging cell aggregates, blocking the lumen of individual sinusoids. The aggregates consisted of parenchymal cells and cell fragments, but did not include leukocytes or platelets. Strikingly, microvascular perfusion failure was associated with Ito cell disintegration and marked dilation of sinusoids (15.6 +/- 0.8 microm vs. 8.8 +/- 0.8 microm; P <.05). This excludes sinusoidal constriction as the cause of nutritive perfusion failure, and may indicate dysfunction of Ito cell-regulated vasomotor control by cryothermia. However, because circulating cell aggregates were frequently observed plugging individual microvessels, dilation of sinusoids may just be the result of passive distension caused by outflow blockade. Analysis of hepatic tissue at 8 weeks after cryothermia did not reveal regeneration and microvascular remodeling, but loss of hepatic tissue, which corresponded well with the tissue area presenting with sinusoidal perfusion failure during the initial observation period after cryothermia. The fact that there was no recovery of sinusoidal perfusion over the initial 2-hour observation period, but loss of tissue after 8 weeks, supports the view that cryothermia induces injury not only by direct low-temperature-mediated action, but also through ischemia caused by irreversible deterioration of the microcirculation.

Management of hepatic metastases

Although the liver is the most common site of metastatic disease from a variety of tumor types, isolated hepatic metastases most commonly occur from colorectal cancer and, less frequently, from neuroendocrine tumors, gastrointestinal sarcoma, ocular melanoma, and others. Complete evaluation of the extent of metastatic disease, both intrahepatically and extrahepatically, is important before considering treatment options. Based on a preponderance of uncontrolled studies for hepatic metastatic colorectal carcinoma, surgical resection offers the only potential for cure of selected patients with completely resected disease, with 5-year survival rates of 25% to 46%. Systemic and hepatic arterial infusion chemotherapy may be useful treatment options in patients with unresectable disease and possibly as an adjuvant treatment after liver resection. Other techniques of local tumor ablation, including cryotherapy and radiofrequency ablation, although promising, remain unproved. Management of hepatic metastases from neuroendocrine tumors and other noncolorectal primary tumors should be individualized based on the patient's clinical course, extent of disease, and symptoms.

Patterns of serum CEA fall after hepatic arterial chemotherapy as sole therapy and combined with cryotherapy for colorectal metastases

BACKGROUND

Hepatic artery chemotherapy (HAC) and cryoablation are treatments for unresectable liver metastases from colorectal carcinomas. Our centre has previously published data that describe survival statistics of patients after each of these treatments. It has also been established that serial serum carcinoembryonic antigen (CEA) concentrations may be used to monitor disease progress, and that the magnitude of fall is prognostic for both treatments. The pattern of fall of CEA following cryotherapy and regional chemotherapy has not previously been compared.

METHODS

In this study, we examined 26 HAC patients and 24 cryotherapy patients.

RESULTS

The mean percentage of the pre-treatment CEA concentration for the HAC group was 60.5% at 50 days and 29.4% at 150 days, and for the cryotherapy group 24.9% at 50 days and 24.3% at 150 days. Calculating the difference between means revealed a significantly different mean fall in the cryotherapy group at 50 days (P < 0.001) and a difference in mean fall at 150 days (P > 0.1) which was not significant. In patients who responded to hepatic artery chemotherapy, the eventual CEA fall was very similar in magnitude.

CONCLUSIONS

The pattern of fall of CEA differs in these two treatments.

Laparoscopic cryoablation of hepatic metastases

Cryosurgery for liver metastases may improve survival for unresectable hepatic metastases. The laparoscopic approach to managing these tumors is a novel method fostered by increasing surgeon and patient interest in minimally invasive surgical techniques and the development of laparoscopic ultrasound and cryoprobes. A retrospective review of our patients who underwent laparoscopic cryoablation of hepatic tumors from April 1996 to December 1997 was conducted. We report on this experience and comment on the feasibility and safety of the procedure based on this early trial.

Fluorodeoxyuridine causes bilomas after hepatic cryotherapy

BACKGROUND AND OBJECTIVES

Hepatic cryotherapy is a method of in situ cytodestruction used for unresectable liver tumours that can be combined with regional cytotoxic administration. We have used intra-arterial chemotherapy with 5-fluorouracil (5-FU) after hepatic cryotherapy but changed to 5-fluorodeoxyuridine (FUDR) because of the arterial toxicity of 5-FU. A new complication was seen.

METHODS

A retrospective case note study was performed of 130 patients who had undergone hepatic cryotherapy followed by regional chemotherapy at our centre. Seven patients received FUDR; 123 received 5-FU.

RESULTS

Biloma at the cryotherapy sites was seen in three patients in the FUDR group; two other patients in this group had other types of hepatic collection. Our previous experience with intra-arterial 5-FU in 123 patients after hepatic cryotherapy showed no evidence of this syndrome.

CONCLUSIONS

Intra-arterial FUDR should not be used after hepatic cryotherapy, at least during the immediate postoperative period.

Renal impairment in hepatic cryotherapy

Cryoshock is a syndrome of coagulopathy, renal, and pulmonary injury following cryotherapy, and its etiology is unknown. The aim of this study was to assess the impact of hepatic cryotherapy on renal function, and whether this effect is related to volume of cryotherapy, and to identify any predictors of renal impairment in patients who undergo cryotherapy. A retrospective analysis of all patients with primary or secondary hepatic malignancy treated with cryotherapy from April 1990 to October 1996 was conducted. Ten of 204 patients with renal impairment (elevation in creatinine of greater than 0.02 mmol/L for more than 2 days postprocedure) were identified. One patient has postoperative pancreatitis with late renal impairment (20 days) and was excluded. The severity of renal impairment was usually modest (mean rise in creatinine of 0.31 mmol/L; SD, 0.19). Two patients required temporary hemodialysis. Only one patient, who had significant cardiac disease, had associated pulmonary injury and shock. Demographic data in both groups were comparable, except for a trend toward more noncolorectal cancer patients in the renal impairment group (4/9 vs 33/194). Patients in the renal impairment group had a greater number of lesions than those of the nonrenal impairment group (3.4 vs 2.1, p < 0.01), as well as larger lesion diameter (2.9 vs 1.9, p < 0.01), increased freezing time (74.7 vs 44.3, p < 0.01), and a higher aspartate transaminase (AST) (2254 vs 1157, p < 0.01). This study suggests that renal impairment is more likely to be seen in patients undergoing more extensive cryotherapy. The number and diameter of lesions together with AST data link renal injury with magnitude of liver injury--all renal impairment patients had an AST > 1000, compared with only 28% of patients who did not.

Anesthetic considerations for hepatic cryotherapy

The evolution of hepatic cryotherapy as an accepted treatment for patients with non-resectable hepatic malignancy has required concurrent evaluation and development of perioperative anesthetic management of these cases. Review of published and institutional experience demonstrates that hepatic cryotherapy presents the anesthesiologist with an array of challenges, all of which are not intuitively apparent. Specifically, such issues as management of coexisting physiologic perturbations of the oncology patient, heat conservation during the procedure, and readiness for a more extensive procedure would be readily anticipated by most clinicians. Description and reasonable management of problems ranging from mild or moderate postoperative thrombocytopenia to the so-called cryoshock syndrome with the possibility of severe postoperative coagulopathy, renal dysfunction, and pulmonary complications, however, could emerge only with the education of experience. The goal of this article is to address the key issues faced by anesthesiologists consulted in the perioperative care of patients undergoing hepatic cryotherapy.

Management strategies for colorectal liver metastases--Part II

Liver metastases are relatively common in colorectal cancer and a small proportion of patients may benefit from resection of these liver metastases. In a selected subgroup of patients, 5-year survival rates of 25-35% may be achieved following liver resection. These survival figures compare favourably with those of patients with untreated liver secondaries. In the second part of this review the surgical and non-surgical treatment options for treating colorectal liver metastases are examined in detail.

Previous intravenous chemotherapy does not alter response rate or survival time of patients with hepatic metastases from colorectal cancer treated by hepatic artery chemotherapy

BACKGROUND

The present paper addressed the issue of whether pretreatment with intravenous (i.v.) chemotherapy affects response rate or survival in patients receiving hepatic artery chemotherapy (HAC).

METHODS

Case note reviews of 164 patients treated in a teaching hospital from June 1990 to July 1996 were carried out.

RESULTS

The response rate and carcino-embryonic antigen (CEA) fall in the two groups was almost identical. There was a nonsignificant survival advantage in the non-pretreatment group.

CONCLUSIONS

Previous administration of i.v. chemotherapy did not affect the CEA response of patients receiving HAC.

Nonresectional therapies for hepatocellular carcinoma

BACKGROUND

Surgical resection is generally accepted as the first choice of treatment for hepatocellular carcinoma (HCC). However, due to its multifocal nature, association with chronic liver disease, and frequent postresectional recurrence, nonresectional therapies are important in the management of a significant proportion of patients with HCC.

DATA SOURCES

A literature review was performed on the current status of different nonresectional treatment modalities commonly employed for HCC. They include direct ablation methods, systemic chemotherapy, transcatheter arterial chemoembolization, external and targeting radiotherapy, hormonal therapy, and immunotherapy. Multidisciplinary therapy resulting in preoperative cytoreduction has also been reported with improvement of therapeutic results.

CONCLUSION

Nonresectional therapies play an essential role in the treatment of inoperable HCC as they lead to satisfactory survival. Percutaneous ethanol injection and transcatheter arterial chemoembolization are the most frequently employed modalities, and they result in a 3-year survival rate of 55% to 70% and about 20%, respectively. Multidisciplinary therapy appears to be the current trend of management and improved survival is achieved especially when unresectable tumors are converted to resectable ones.

Cryosurgery on the Treatment of Hepatic Tumors

BACKGROUND: Primary and metastatic tumors in the liver are difficult to treat. When surgical resection is not feasible, cryotherapy is one of the several alternative approaches. METHODS: The data on outcomes from hepatic resections are reviewed, and the rationale and techniques of performing cryosurgery for unresectable hepatic cancers are described. The literature is reviewed and combined with the experiences of the authors on cryosurgery for management of hepatic tumors. RESULTS: The indications and techniques for performing cryosurgery are now well established. The procedure is relatively safe, and long-term survival rates of over 20% may be achieved. CONCLUSIONS: While cryotherapy is effective for localized tumors in the liver, additional adjuvant approaches are required to control disease in the untreated liver. Endoscopic techniques may minimize patient morbidity.

Treatment of colorectal cancer: hepatic metastasis

Almost one-third of patients dying from colorectal cancer have tumor limited to the liver. Systemic chemotherapy is the appropriate palliative management of patients with metastases to the liver and other sites. For many patients with isolated hepatic metastases, systemic chemotherapy is also the most appropriate treatment. However, results with systemic chemotherapy indicate that one-third or less of patients will respond to such treatments, and long-term survival is rare. In this report we provide information concerning the natural history of colorectal hepatic metastases, followed by the expected benefits with systemic chemotherapy. This information provides background for the regional therapeutic strategies of surgical resection, cryosurgery, and hepatic artery chemotherapy. We discuss the selection factors appropriate for such treatments, morbidity and mortality, and the potential long-term benefits of such approaches. The last section focuses on surgical considerations in hepatic resection and hepatic artery chemotherapy.

Arterial therapy of hepatic colorectal metastases

Considerable experience of the treatment of irresectable hepatic colorectal metastases has accumulated over the past three decades. In this review, the rationale for hepatic artery treatment of colorectal metastases to the liver is presented and various access techniques and chemotherapeutic agents for infusion are discussed. Randomized trials of hepatic artery chemotherapy (HAC) are analysed, and the promising results of recent studies combining less toxic and more effective agents are summarized. Continuous infusion pumps provide the most reliable and long-lasting access for HAC. Appropriate surgical techniques and medical management can minimize complications. Although tumour progression is best controlled by HAC, a clear-cut survival advantage has yet to be demonstrated. While hepatic artery infusion chemotherapy cannot yet be recommended outside investigational protocols, the experience gained so far should stimulate further studies.

Primary resection and synchronous regional hepatic chemotherapy or cryotherapy for colorectal cancer with liver metastases

Twenty-two patients with colorectal cancer and synchronous unresectable hepatic metastases were treated by resection the primary tumour with concurrent insertion of an Infusaid infusaport system for regional chemoperfusion (hepatic arterial 20, portal venous 2). Four patients in addition had cryotherapy the liver metastases. Morbidity from the synchronous procedures was minimal. Median survival was 10 months. Four patients with poorly-differentiated tumours had a poor response, with a median survival of 3.75 months.

Hepatic artery chemotherapy for colorectal liver metastases

Fifty per cent of patients with colorectal cancer develop hepatic metastases but only a minority are candidates for potentially curative surgical resection. Hepatic artery chemotherapy (HAC) has been used to treat patients with non-resectable metastases confined to the liver. Although response rates to HAC have been shown to be higher than response rates to systemic chemotherapy, the advantage in terms of survival has been debated. Furthermore, HAC requires surgical catheter placement which adds to the cost and morbidity of treatment. There have now been eight prospective randomized trials of HAC vs intravenous chemotherapy and/or supportive therapy. The present paper analyses the results of these trials with particular reference to survival. Surgical morbidity, treatment-related toxicity and cost are also discussed.

Surgical options in the treatment of hepatic metastasis from colorectal cancer

Current data indicate that liver resection is the only available treatment that regularly produces long-term survival with possible cure in patients with metastatic colorectal carcinoma to the liver. Although a number of clinical or pathologic factors predicts a poor outcome, the only absolute contraindications to liver resection are general health incompatible with recovery from major hepatic resection or clear evidence of wide dissemination of disease. Important areas for future study include the potential role of adjuvant regional chemotherapy after resection and cryoablation of "close" margins. For patients with unresectable disease, operative therapy also plays an important role. Multiple operative modalities hold promise in palliative treatment in the setting of clinically incurable disease. It is imperative that a large randomized trial of regional chemotherapy be performed allowing no crossover and with mortality as an endpoint. Additionally, the role of cryoablation begs systematic investigation to ensure proper use of this modality.