| BackgroundPrimary hepatocelullar carcinoma (HCC) is one of the most common malignant tumors in the world and its mortality rate is the second highest in China. The prognosis of HCC patients is progressive usually to intra-liver recurrence and metastasis. Cancer cell dissemination through the portal vein system is the most common way of intra-liver metastasis and recurrence. Liver cancer has a high risk of portal vein tumor thrombosis, autopsy show that the rate of HCC patients with portal vein tumor thrombosis (PVTT) was 44-84% while clinical data also showed that it was 34-50%.When the sign of advanced stage tumor PVT was present, the patients often succumb within 2.4~2.7 months, usually to complications of cirrhosis, such as variceal bleeding or progressive liver failure. With the development of medical image techniques, many ultrasound-guided interventional therapy methods of liver cancers have been emerged and become an important clinical method. Ultrasound-guided interventional thermotherapy is a method that change physical energy including microwave, laser, et al into heat and cause coagulate necrosis of tumor tissue with high temperature. It has already been the focus of present research. And radiofrequency, microwave, laser had been widely used in the treatment of liver cancers in clinical. Local heat that caused by microwave can localize in the tumor tissue, therefore cause coagulate necrosis, the area of necrosis is related to the work time, the power, the experiment protocol and the material. If the power and time are controlled properly, an elliptical area can be formed which may make the portal vein tumorthrombosis necrotic.The present research of laser showed that laser ablation had good effect on thekilling of liver cancers. Laser ablation is a method that change light energy intoheat energy, and cause high temperature in the tumor, with the proper power, thetumor tissue can be charred and even gasified. Researchers have already put it inthe use of ablation of tumor thrombosis.Yet little research has been reported of laser ablation of hepatic portal veintumor thrombosis and there is no report of ultrasound-guided ablation of hepaticvenous tumor thrombosis (HVTT).This study is in order to evaluate ultrasound-guided interventionalthermotherapy of portal vein and hepatic venous tumor thrombus from the invivo and in vitro experiment and clinical practice.Materials and Methods 1 The clinical part of Microwave therapy1.1: Three HCC patients with hepatic portal vein tumor thrombus (2 were PVTT and one was HVTT) were confirmed by clinical surgery or biopsy during 2004 to 2005 in our hospital were enrolled in this srudy.2 Males and 1 female, age ranged from 45 to 67 years old, median age 53.6 years old. The count of platelet should more than 5* 109/L, PT time less than 18 second. All patients were voluntary to undergo ultrasound-guide portal vein or hepatic venous tumor thrombosis laser ablation. Before treatment the patients or their family members signed their name as testimony. 1.2 Evaluation after treatmentOne month after treatment, ultrasound, contrast CT / MR were performed to find out what changing of shape and size of tumor thrombosis, then every three month the patients were callback. If there were tumor or tumor thrombus found again, then therapy was performed again. All patients' survival time were followed. 2. In vivo part of Microwave therapyTwo PVTT patients' survival time were not been prolong(2 of them were dead post 3.5months and 6.5months after therapy), so we perform further investigation of more higher power at 60 W, 80 W and 100W.2.1 Subjects: fresh pig livers2.2 Using the Microwave device made by Nanjing new technical Institute.2.3 Evaluation after treatment: measure the size of high echo focus and then dissect the burned tissue to measure the size of necrosis area.2.4 Statistical analysis: Descriptive analysis. 3. The experiment part of laser3.1 In vitro experiment3.1.1 Subjects: fresh pig livers3.1.2 Ultrasound guided laser ablation of liver tissue using semiconductor laser ablation device-SurgiLas, produced by Lingyun CO. LTD;Shanghai, China3.1.3 Evaluation after treatment: measure the size of high echo focus,then dissect the burned tissue to measure the size of coalpit area and necrosis area..3.1.4 Statistical analysis: Descriptive analysis.3.2 hi vivo experiment3.2.1 Subjects: six New Zealand rabbits(supported by animal center of Zhejiang University school of medicine),weight ranged from 2.4 kilogram to 2.6 kilogram, all rabbits' liver tissues underwent laser ablation with different power and different time. After treatment, dissect the burned areas lengthways, measure the coalpit and the necrosis area, find the change of liver tissue under microscopy.3.2.2 After anesthesia, all rabbit liver tissues underwent ultrasound-guided percutaneous laser ablation.3.2.3 Evaluation after treatment: After treatment measure the size the high echo area under ultrasound;dissect the burned areas lengthways, measure the coalpit and the necrosis area. Found the laser ablation areas that were treated with different power and different time.3.2.4 Statistical analysis: Descriptive analysis.4. The clinical practice of laser3.1 Subjects:Four HCC patients with hepatic venous thrombosis who were comfirmed by clinical surgery or biopsy during 2004 to 2005 in our hospital were enrolled in this study.4 males, age ranged from 48 to 74 years old, median age 61.5. The count of platelet should more than 5*109/L, PT time less than 18s.All patients were voluntary to undergo ultrasound-guide portal vein or hepatic venous thrombosis laser ablation. Before treatment the patients or their family members signed their name as testimony.3.2 Evaluation after treatmentOne month after treatment, ultrasound, contrast CT / MR were performed to find out what changing of shape and size of tumor thrombosis, then every three month callback. If there were tumor or tumor thrombus found again, then therapy was performed again.All patients' survival time were followed. 3.4 Statistical analysis: Descriptive analysis.Conclusion and DiscussionMicrowave therapy: 1. Basic experiment show high power microwave can form a long oval type in the liver. 2.The clinical part show the microwave power at 60W were not prolong the PVTT patient survival time(one dead post 3.5month and the other dead post 6.5month). One case of HVTT patient was performed at a power at 100W, the contrast-enhanced ultrasound show no enhance in the tumor thrombosis post therapy and he is still live post 6 month. Laser therapy: 1. In this study both in vitro and in vivo liver tissue can bring a small cavum around the head of fiber after laser ablation and at the same time a strap of coagulation necrosis area around the small cavum was formed. When the laser was emissioned continuously and the fiber was dropped back continuously, it caused a tunnel in liver, and around the tunnel a columnar strap of coagulation necrosis was formed.2. Clinical curative effect: In this study all patients underwent interstitial thermotherapy of PVTT or HVTT successfully,including two cases of left branches of portal veins, one right branch of portal vein and one hepatic vein. Followed time ranged from 6 months to 13 months. All the surgeries performed safely. The followed data of these patients show some of them had bypass blood vessels in the portal vein.ConclusionThis study showed that ultrasound-guided interstitial thermotherapy of PVTT and HVTT of HCCs had rather good effect in short dated, and there is little complication. The thrombosis tumor shrinked, and patients' survive time had prolonged. It has extended the use of microwave and laser in the hepatic vessels' tumor thrombosis. Ultrasound-guided microwave firstly treated on PVTT. Laser and microwave thermotherapy were treated firstly on HVTT. A randomized study should be needed to confirm the efficacy of this therapy. |
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