Palliative cryosurgery for rectal carcinoma

Large Bowel Obstruction following Endoscopic Spray Cryotherapy for Palliation of Rectal Cancer Bleeding

We report a unique case of a 79-year-old woman with metastatic rectal cancer who developed bowel obstruction following endoscopic cryotherapy with liquid nitrogen for palliation of bleeding in the rectum. She developed abdominal distention and pain following the procedure. Computed tomography of the abdomen revealed a paraumbilical hernia containing a segment of transverse colon resulting in partial bowel obstruction. It appears that the recurrent freeze-thaw cycles with poor decompression of the colon despite active venting suction during cryotherapy may have resulted in bowel distention and collapse, causing conformational changes resulting in partial bowel obstruction due to a paraumbilical hernia.

Cryosurgery for Tumors — A Clinical Overview

Cryosurgery, a method of treating disease by the production of freezing temperatures in the tissue, is a useful technique for the treatment of tumors. When the modern era of cryosurgery began in the mid 1960's, the technique was used only for tumors easily accessible by direct observation or via endoscopy, such as those of the skin, oral cavity, and prostate gland. In general, the technique had limited usefulness in the next two decades. However, with the advent of intraoperative ultrasound as a method of monitoring the process of freezing and with the development of more effective cryosurgical apparatus, the cryosurgical treatment of tumors of the viscera and other deep tissues became practical in the 1990's. This review assesses the present day status of cryosurgery in the management of diverse tumors.

Cellular immunologic response to primary cryoablation of C6 gliomas in rats

The immunological consequences of cryoablation for gliomas are largely unknown. cryoablation is an attractive therapeutic option for tumors due to its minimally invasive nature. cryoablation is also potentially immunogenic. With an aim to explore changes in cellular immunity following argon-helium cryosurgery, we established Wistar rat models bearing subcutaneous C6 glioma and divided the rats into the normal control (30 rats), sham-operated (33 rats), surgical resection (30 rats), and cryosurgery (33 rats) groups with corresponding treatments. The tumor cell morphology was observed, and changes in the T lymphocyte subset and NK lymphocyte subset and the ratio of Th1/Th2 were assessed with flow cytometry following the cryosurgery. The results showed that subcutaneous tumor implantation was successful in all cases and this was confirmed histologically. Compared with surgical resection that caused significant reduction in CD3(+), CD4(+), CD14(+), CD16+56 cell percentages, cryosurgery resulted in significantly increased percentages of CD3(+), CD4(+), CD14(+), CD16+56 cells (P < 0.05) with a increase of the Th1/Th2 ratio 7 days after the operation. These results demonstrate that in addition to tumor cell destruction, cryosurgery also results in enhanced cellular immunity, suggesting the great potential of argon-helium cryosurgery in clinical management of gliomas.

Argon-helium cryosurgery for treatment of C6 gliomas in rats and its effect on cellular immunity

Argon-helium cryosurgery has shown encouraging therapeutic effects on some solid tumors, but its application in the treatment of gliomas remains poorly documented. To explore the cell apoptosis at the glioma foci and the cellullar immunity changes following argon-helium cryosurgery, we established Wistar rat models bearing subcutaneous C6 glioma and divided the rats into the normal control (20 rats), sham-operated (32 rats), surgical resection (20 rats), and cryosurgery (32 rats) groups with corresponding treatments. The postoperative changes in the findings by magnetic resonance imaging (MRI) and tumor cell morphology were observed, and the cell apoptosis at the tumor foci was assessed with TUNEL assay. Flow cytometry was performed for analysis of the T lymphocyte subset changes following the cryosurgery. The results showed that cryosurgery induced not only destruction of the tumor cells but also cell apoptosis around the cryablation foci. Compared with surgical resction that caused significant reduction in CD3+ and CD4+ cell percentages, cryosurgery resulted in significantly increased percentages of CD3+ and CD4+ cells (P<0.05) with a relative increase of the CD4+/CD8+ cell ratio 14 days after the operation. These results demonstrate that in addition to tumor cell destruction, cryosurgy also results in enhanced cellular immunity and antitumor immune response of the C6 glioma-bearing rats, suggesting the great potential of argon-helium cryosurgery in clinical management of gliomas.

Endoscopic methods (other than stents) for palliation of rectal carcinoma

Patients with unresectable or metastatic rectal cancer may have symptoms of obstruction, bleeding, pain, or tenesmus. Insertion of a self-expandable metal stent is the most durable nonsurgical method for relieving obstruction and has been reviewed in the previous article. Other endoscopic methods of palliating obstruction have been largely replaced by expandable metal stent placement. However, laser ablation is still a useful therapy for some patients, particularly when the predominant symptom is rectal bleeding. The indications and results of endoscopic laser therapy along with other endoscopic treatments for the palliation of rectal cancer will be reviewed here.

Non-operative management of the primary tumour in patients with incurable stage IV colorectal cancer

BACKGROUND

Excision of primary colorectal cancer associated with irresectable synchronous metastases confers high morbidity and mortality with uncertain benefit.

METHODS

For patients with incurable stage IV colorectal cancer, minimally symptomatic primary tumours were left in situ and 5-fluorouracil-based chemotherapy was administered systemically. Primary tumour-specific complications and survival were monitored.

RESULTS

There were 13 men and 11 women with primary tumours in the right colon (eight), transverse colon (one), sigmoid colon (eight) or rectum (seven). Eleven patients had metastases limited to the liver (liver replacement less than 25 per cent in one, 25-50 per cent in four and more than 50 per cent in six) and 13 patients had extrahepatic disease (lung or peritoneum). Four patients with sigmoid colon tumours developed bowel obstruction, which required an uncomplicated operation in two and deployment of colonic stents in two patients, at 1, 3, 12 and 20 months from diagnosis. Three further patients underwent right hemicolectomy for abdominal pain of uncertain aetiology, with poor symptomatic relief, and another had a potentially curative operation following disease downstaging. The overall median survival was 10.3 months with a 1-year actuarial survival rate of 44 per cent.

CONCLUSION

A policy to defer resection of minimally symptomatic primary colorectal cancer is associated with a low risk of complications before death from progressive systemic disease.

Optical properties of native and coagulated porcine liver tissue between 400 and 2400 nm

BACKGROUND AND OBJECTIVE

Laser induced thermotherapy (LITT) is a promising treatment for irresectable liver tumors. For predicting the effects of laser applications and optimizing irradiation planning in LITT, knowledge about light distribution in tissue, optical tissue properties (absorption, scattering, anisotropy, penetration depth) and their changes due to thermal denaturation is indispensable.

STUDY DESIGN/MATERIALS AND METHODS

The optical parameters in healthy porcine liver were determined in the native state and after thermal coagulation using a double integrating sphere system in the wavelength range of 400-2400 nm.

RESULTS

Optical parameters showed significant fluctuations in the examined wavelength range mainly due to the water and hemoglobin content in the tissue. The greatest optical penetration depth of 7.46 mm was achieved at 1070 nm. After thermal coagulation, a clear increase in scattering and a slight decrease in absorption was found, which results in a decreased optical penetration depth.

CONCLUSIONS

In order to ensure a safe and effective procedure, an adjustment of the laser power to the decreasing penetration depth is recommended during therapy. These results provide a better understanding of laser-tissue interaction and may be helpful to investigators in the field of light dosimetry in liver tissue.