[Cryotherapy of liver metastases. Initial results]

Inoperable colorectal liver metastases: a declining entity?

BACKGROUND

Untreated colorectal liver metastases (CLMs) have a dismal prognosis. Surgery remains the gold standard of treatment, but many patients will have inoperable disease at presentation. Until recently, the outlook for such patients was bleak. The purpose of this review was to report on available options in the treatment CLMs, which would be considered unresectable by conventional evaluation.

METHODS

Inclusion criteria were articles published in English-language journals reporting on either retrospective or prospective cohorts of patients undergoing treatment for conventionally inoperable CLM. Main outcome measures were survival, resectability rates, morbidity and mortality following treatment of the patients' disease.

RESULTS

Improved chemotherapy regimes and other innovative treatments have opened up new options for such patients and may even render conventionally inoperable disease resectable. The aim of treatment should be down-staging of metastases to achieve resectability, however, other treatments such as ablation may be also be used (either alone or in conjunction with resection).

CONCLUSION

A nihilistic attitude to the patient with seemingly inoperable liver metastases should be discouraged. Discussion of such patients at multi-disciplinary meetings is essential in order to plan and monitor treatments.

A pig model of hepatic cryotherapy. In vivo temperature distribution during freezing and histopathological changes

We aimed to assess the temperature distribution in the cryolesion during hepatic cryotherapy and the association with postoperative histological changes to optimise the technique and allow better preoperative planning. Hepatic cryolesions were produced in 22 pigs following laparotomy using a CMS-cryosystem and 8mm-AccuProbe-Cryoprobes. The temperature was measured in 1 min intervals at different distances from the probe during freezing. The animals were treated in 5 groups: (i) single freezing of 20 min; (ii) double freezing of 20 min each; (iii) single freezing of 40 min; (iv) single freezing of 20 min (n=4), histology at 1 week p.o., and (v) single freezing of 20 min and Pringle manoeuvre; [(i)-(iii) and (v): histology at 24 h p.o.]. The mean diameter of the -38 degrees C isotherm, i.e., the zone of effective treatment for colorectal metastases was 37 mm for group (i) with a mean iceball diameter of 59 mm and about 46 mm for groups (ii, iii, and v) with mean iceball diameters of 78, 75, and 75 mm, respectively. At 7 days postoperatively secondary necrosis was seen in the largest central part of the lesion, wherever temperatures of -15 degrees C or lower were achieved during cryosurgery. Under the hypothesis that -38 degrees C is the effective temperature for the destruction of colorectal liver metastases, a lesion of 37-mm diameter may be effectively treated with a single 8mm-AccuProbe-Cryoprobe and a 20 min single freeze cycle and a lesion of 46 mm may be effectively treated when a double freeze-thaw cycle of 20 min each, a single freeze cycle of 40 min, or a 20 min single freeze cycle with additional Pringle manoeuvre is used, when it is perfectly placed in the lesion.

Two-stage liver resection and chemotherapy for bilobar colorectal liver metastases

BACKGROUND

A significant number of patients with colorectal metastatic disease confined to the liver are inoperable at assessment. For these patients, the outlook is poor. Chemotherapy can 'down-stage' some tumours and render them operable. The authors present a series of patients with inoperable disease despite down-staging with chemotherapy, who underwent a two-stage resection to clear their metastatic disease.

METHODS

The case-notes of 11 patients who were found to have inoperable hepatic metastatic disease were identified using computerised medical records and mean hospital stay, survival and long-term follow-up data was noted.

RESULTS

The mean follow-up from initial resection was 13.5 months (range of 5-20 months). Three deaths were recorded in the follow-up interval. Causes of death included recurrence of hepatic disease following completion of two-stage resection, progression of original hepatic disease leading to inoperability at second stage operation and recurrence of original primary colorectal tumour. The mean survival in the patients who died was 17 months (range of 15-19 months). The remaining patients are alive to date with six patients showing no evidence of hepatic recurrence, follow-up period of 13 months (range of 8-20 months). One patient developed de novo prostate cancer and is awaiting his second liver resection, and one patient has stable hepatic disease with no evidence of progression.

CONCLUSION

Two-stage liver resection can prolong survival when compared to chemotherapy alone, with a recurrence rate equivalent to ablation techniques. Longer-term studies are needed for further evaluation.

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.

Percutaneous cryoablation in treatment of liver cancer: a report of 31 cases

AIM

To describe the indication, efficacy and clinical significance of percutaneous cryoablation in the treatment of liver malignancy.

METHODS

Total 31 patients with histologically or clinically confirmed primary or metastatic malignancies were treated pucutaneously under ultrasound guidance using the cryocare surgical system from July 2001 to January 2002. All patients were followed up to determine the serum tumor marker, and reveal CT scans, MRI images or utra-sound images.

RESULTS

This therapy was performed in 31 patients including 26 cases with Child A liver reserve, 4 cases with Child B and 1 cases with Child C. There were 21 cases of primary liver cancer and 10 metastastic liver cancer. AFP positive small liver cancer became AFP negative in 80% patients. The rate of completely concreted necrosis in small hepatic cancer with negative AFP was 66.7%, shown by CT or MRI. The curative rate for metastasis liver cancer was 50% at CT, MRI or tumor marker level.

CONCLUSION

Percutaneous cryoablation is a kind of new palliative treatment for liver carcinoma. It is minimally invasive, safe and effective especially for patients with unresectable liver cancer.

Comparison of iceball diameter and temperature distribution achieved with 3-mm accuprobe cryoprobes in porcine and human liver tissue and human colorectal liver metastases in vitro

We aimed to assess the thermal profile and size of iceballs produced by Accuprobe cryoprobes in fresh porcine and human liver and human colorectal cancer liver metastases in vitro to allow better planning of cryosurgical treatment of liver metastases. Iceballs were produced by a 20-min single freeze cycle using 8-mm cryoprobes in pig liver in a waterbath at 37 degrees C (n = 8) and 3-mm cryoprobes in pig liver (n = 8), human liver (n = 3), and human colorectal cancer liver metastases (n = 8). The iceball diameters and the temperatures at different distances from the cryoprobe were measured. Mean iceball diameters produced by 8-mm cryoprobes in pig liver were 56.3 mm and varied from 38.7 to 39.6 mm for 3-mm cryoprobes in the different tissues used. There was no significant difference in iceball size in the different tissues. The diameter of the zone of -40 degrees C or less was approximately 44 mm using 8-mm cryoprobes in porcine liver and between 27 and 31 mm using 3-mm cryoprobes in the different tissues examined. The results may allow better preoperative planning of the cryosurgical treatment of liver metastases with Accuprobe cryoprobes.