| BackgroundAlthough the gold standard of management of primary and matastatic liver malignancies ramains surgical resection, unfortunately ,only 20-30 percent of all patients presenting with intrahepatic disease are appopriate candidate for resection, and a high incidence of intrahepatic recurrence, ranging from 50% to 60% after initial treatment because of most patients with HCC having underlying chronic liver disease caused by hepatitis virus. There is therefore a need for treatment of unresectable tumors in the liver. In the last few years, minimal invasive thermotherapy technique such as percutaneous radiofrequency(RFA), focused ultrasound, Nd:YAG interstitial laser thermotherapy(LITT) have become available for destruction of hepatic carcinomas and inprovement in overall median and actuarial survivals inunresectable patients successfully undergoing local ablation. Overall, their widespread clinical application has been hindered by ineffective or unpredictable tumour destruction or high cost.In contrast to conventional medical lasers, the recently developed diode lasers are semiconductor solid-state devices that are excited by electrical current. They exhibit high efficiency of 25% to 35%, compared with 1% to 10% for conventional lasers. Since diodelasers are very efficient, they do not require any special utilites. They can be operated using regular electrical power and require minimal maintenance. These features may make them attractive from practical and economical standpoints, and for potential office-based procedures to be done under local anesthesia. For example , it has been reported to be used in treament of central nervous system tumors and prostatic hyperplasia. In the present experimental pilot study , we attempted to assess the feasibility, safety, and effectiveness of diode laser for liver tumors.Laser-induced thermotherapy (LITT) or interstitial laser thermotherpy is an in situ ablation technique for the treatment of maligant tumors of the liver. The potential of LITT is that laser light is directly transmitted through flexible bare fibers into the tumor tissue with highprecision. The biologic effect of the laser light is based on the transformation of laser photon energy into heat by the absorption of tissue-specific chromophores. The aim is to induce uniform coagulation necrosis of the treatment volume. Of great importance to the method's success is the size of the induced coagulation necrosis, which must contain the whole volume of the tumor tissue. This lesion size largely depends on the temperature distribution in the target volume, which is determined partly by the blood perfusion in the target organ. In organ with a high blood perfusion , such as the liver, a cooling effect results because of the temperature difference between the hyperthermic area and blood. On the other hand, liver cirrhosis will lead to a great changement of hepatic blood inflow hemodynamics, such as portal hypertension and collateral circulation formation. A few study about temporary interruption of hepatic blood flow by occlusion of hepatic inflow vessels (Pringle maneuver) during LITT has been proven to increase its efficacy. But until now, it hasn't been studid deeply about the problem of the influence of temporary interruption of hepatic blood flow by occlusion of different hepatic inflow vessels during diode laser-induced thermotherapy in the treatment of liver tumors, especially for the cancer with liver cirrhosis.So the present study include: (l)Design andinvention of hepatic tumors thermotherapic system of diode laser with scanner fiber; (2)Experimental study of diode-laser induced thermocoagulation on hepatic tissue with scanner fiber tip; (3) The influence of temporary interruption of hepatic blood inflow to diode-laser induced thermocoagulation on hepatic cancer; (4) The influence of temporary interruption of hepatic blood inflow to diode-laser induced thermocoagulation on hepatic cancer with cirrhosis.Methods(1) The diode laser for thermoco...
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