Search

A 65-year-old man was diagnosed as having hepatocellular carcinoma (HCC) with liver cirrohosis classified clinical stage, which caused by hepatitis C virus. Abdominal contrast CT showed HCC in the diameter of 2 cm located Segment 4. Laparoscopic microwave coagulation therapy under hepatic blood flow occlusion using clamp was performed. We applied the coagulation time for 10 minutes with an output of 80 watts for 60 seconds at a time. After 2 months the hepatic tumor was completely enclosed within the coagulation area and no recurrence was showed for 14 months after procedure. We have reported that the coagulation areas with the hepatic blood flow occlusion was about twice as big as that without blocking the hepatic blood flow. This suggested that a 3 cm hepatic tumor can be controled by this method. We proposed that laparoscopic microwave coagulation therapy under hepatic blood flow occlusion should be selected for HCC of small size or middle-size hepatic tumor and high risk patients.

The possible use of percutaneous microwave tumor coagulator (PMCT) by using CT for local tumor recurrence of rectal cancer was studied in this paper. Preliminary study was performed using adult Landrace pig and we applied the coagulation time for 3 minutes. The CT guided PMCT was performed for patient with local abdomino-perineal excision. The tumor in the pelvic space were observed on CT images. With patient in the prone position on the CT table, a 14-gauge needle was used to penetrate the tumor under epidural and local anesthesia.PMCT was performed with an output of 60 watts for 60 seconds at a time. Effects of the PMCT were evaluated by CT images obtained three months after the therapy, there was no evidence of growth for the tumor on the CT images. Clinical symptoms disappered soon after the therapy, and no major complication was observed.Results of this study suggests that the CT guided PMCT therapy may be useful for local recurrence of rectal cancer.

Using the bovine liver and experimental deep electrodes, we investigated the coagulation effect in ischemic livers in an attempt to increase the range of coagulation of the deep electrodes. The hepatic blood flow was obstructed by blocking the hepatic artery (A), the portal vein (P), or both the hepatic artery and portal vein (AP), and for comparison, coagulation was performed without blocking the hepatic blood flow (C) in control animals. Two electrodes were used for microwave coagulation ; a 1.6-mm shell-type deep electrode (shell-type), and a 3-mm experimental electrode (30 NL). After coagulation, each sample was fixed in 10% formalin and sliced for histological examination. There was a brown boundary area between the coagulated and non-coagulated areas.When the hepatic blood flow was not blocked and coagulation was performed using the shell-type deep electrode at 60W for 2 minutes, a brown boundary area of 1 to 3 mm was seen. The internal diameter of the coagulated area was 23 × 11 mm, and its external diameter including the brown boundary area was 26 × 16 mm. When the hepatic artery or the portal vein was blocked to obstruct the hepatic blood flow, the internal diameter of the coagulated area was 51 × 20 mm, and its external diameter was 56 × 34 mm. Furthermore, on using the 30 NL electrode was used for coagulation at 60W for 2 minutes, the maximum internal and external diameters of the coagulated areas were 25 × 16 and 34 × 27 mm, respectively, when the hepatic blood flow was not blocked (C), 27 × 19 and 35 × 29 mm, respectively, when the hepatic artery was blocked (A), 24 × 21 and 35 × 34 mm, respectively, when the portal vein was blocked (P), and 27 × 26 and 68 × 50 mm, respectively, when the hepatic artery and portal vein were blocked (AP). This indicated that the brown boundary area increased when the portal vein was blocked, and when the hepatic artery and portal vein were blocked, the diameter of the coagulated areas was about twice as big as that without blocking the hepatic blood flow. HE-staining of the cross sections of boundary areas showed shrunken nuclei and intercellular hemorrhagic changes. This suggested that a 3-cm hepatic tumor can be controlled by a single microwave coagulation inserting the experimental electrode into the center of the tumor while blocking the hepatic blood flow.