Objectives : To assess the potential safety and utility of the microwave tissue coagulation technique for laparoscopic partial nephrectomy, we applied this technique to a canine model, using a nobel laparoscopic dissector for manipulation of the kidney. Methods : Ten adult mongrel dogs underwent laparoscopic partial nephrectomy using the microwave tissue coagulator to obtain hemostasis without clamping the renal artery and a nobel dissector to stabilize the kidney without renal mechanical injury. Three, 4 and 6 months after the operation, the renal remnants obtained by autopsy and histologically examined. Results : The laparoscopic partial nephrectomy wave performed without renal ischemia using the microwave tissue coagulator and a nobel dissector in all animals without any intraoperative accidents. The estimate blood loss was 19.0 ± 7.3 ml (mean ± S.D.). The mean operative time was 49 ± 10 minutes (mean ± S.D.). Temperature of the kidney and circumferencial organs could be controlled among 37.0 to 45.0 °C by the ventilation of the intraabdominal warmed carbon dioxide. The postoperative course of all dogs was satisfactory and uncomplicated. All animals resumed normal preoperative activities by postoperative day 4. By autopsy, all dogs had no evidence of the injury of organs, retroperitoneal hematomas and urinomas. Histological findings of the renal specimens revealed no heat injury of renal remnants and the coagulated area was well limited to 10 mm in depth from the cut surface of the renal remnant. Conclusions : Results of laparoscopic operation, thermal distribution, postoperative course and histological findings in a canine model suggest that the microwave tissue coagulation may be a safe, feasible, and useful technique for laparoscopic partial nephrectomy of patients with selected renal tumors.
Purpose of this study was to evaluate the effectiveness of microwave tissue coagulation (MTC) therapy at low out put irradiation in the management of the malignant liver tumor. The liver tumor of the rat was irradiated at the out put of 50 watts for 30 seconds ; Group C, 10 watts for 30 seconds ; Group B and 10 watts for 15 seconds ; Group A at a time. In all of the groups, DNA damage was observed in histological findings with ethidium bromide. Any effect of MTC was not recognized in Group B and C in histological findings with hematoxylin-eosine (H-E) dyeing, however. Furthermore, cytostatic change was observed with dye exclusion test in group B and C. Thus, it suggests that the liver tumor after MTC is damaged satisfactorily at low out put irradiation, Even if it is judged that the cell viability is retained in histological findings with H-E dyeing.
In VX2 tumor model of Japnanes white rabitts, fundamental investigation on antitumor effects of microwave irradiation with w/o/w polyhematoporphyrin ether/ester (PHE) emulsion ware carried out. The intratumoral concentration of PHE an 6 houre after local injection of w/o/w PHE emulsion (involving PHE 0.5 mg/kg) was 10.4 ± 2.4 μg/ g, and it was almost equal to the concentration after intravenous administration of PHE (2 mg/kg). On the other hand, serum concentration of PHE after local injection of w/o/w PHEE emulsion was under lomit of measuement. The reduction ratio of the tumor by microwave irradiation after administration of PHE was observed 89.8 ± 12.1 % local injection of w/o/w PHE emulsion and 77.4 ± 20.7 % in intravenous administration of PHE, respectively without hyperthermic effect caused by microwave itself. Antitumor effect was not recognized in microwave irradiation alone. In conclusion, local injection of w/o/w PHE emulsion may be beneficial as an adminitration route of PHE and microwave irradiation after PHE administration has possibility for a new treatment of superficial malignant tumors.
The level of reflected wave that is appeared when microwave was output is different by the condition of junction which is connected the output cable or electrode. We devised the equipment to prevent miss-operation by using this characteristic. As a result, we made it possible to give warning for miss-operation by using the wave which is subtracted reflected wave from forward wave. And we tried to find the timing that coagulation finishes, using the characteristic that level of reflected wave changes with spread the coagulated layer.
Although hepatectomy and percutaneous ethanol injection therapy have been widely used in the treatment of small hepatocellular carcinomas of less than 3 cm in diameter in Japan, it is almost impossible to treat all small hepatocellular carcinomas according to one therapeutic method because both powerful treatments have various limitations. In patients with small hepatocellular carcinomas in whom these treatments are inappropriate, endoscopic or mini open microwave coagulo-necrotic therapy represents a new therapeutic alternative. In cases where any of these powerful local therapies can be performed, the selection among these three therapeutic options of hepatectomy, percutaneous ethanol injection therapy, and endoscopic or mini open microwave coagulo-necrotic therapy should be based on the patient's clinical and pathologic status. The addition of this new therapeutic method should improve the outcome in these patients.
The possible use of percutaneous transhepatic microwave tissue coagulation (PTMTC) therapy for the liver tumor was studied in this paper. Macroscopic changes in the resected pig liver after microwave irradiation with a new type needle-electrode of that size was 18 gauge was first carried out, MTC was performed at the out put of 30 watts for 30 seconds at a time. The maximum coagulation area of the PTMTC in the fresh cut surface of the liver was macroscopically 20 mm × 10 mm in size when it was irradiated continuously from second to five times, and was oval shaped. PTMTC therapy was second performed in the patient with hepatocellular carcinoma. Tumor was not pointed out in the computed tomography six months after PTMTC therapy and alpha fetoprotein as tumor marker declined to almost within normal limits three months after PTMTC therapy. Thus, the results suggest that PTMTC is the useful therapy in the patients with small liver tumor as a bed side treatment.
The first requisite for successful resection of the liver is sufficient functional reserve of the residual liver. The extent of safe resection in liver disease is so remarkably limited that the big vessel should be reconstructed when extensive resection of the liver including the big vessels is necessary for the tumoral extirpation. Microwave coagulation therapy (MCT) under laparotomy has tumor lethal effect with less critical impairment of live function than surgical resection. In case of the microwave coagulation of tumor involving a big vessel, we couldn't ask for a better result than that the involved vessel wall falls in necrosis accompanied with the tumor mass and that the vessel is kept patent. Histological study using canine model suggesting that conventional coagulation resulted in wall necrosis of the vessel and the maintained patency at intervals of 8 mm from the center of coagulation electrode, successful coagulation for the case with the tumor of segment 4 invading the umbilical and horizontal portion of the Glisson sheath was here by presented.
We introduced the procedure and the technique of percutaneous microwave coagulation therapy (PMCT) for small liver cancer. PMCT with a microwave electrode for deep lesion was done by an ultrasonic guide under local anesthesia. PMCT may be utilized simply and safely for the treatment of small liver cancer, and also be a useful treatment in combination with conventional palliative managements for recurrent tumors after hepatectomy.
Recent years, we experienced various treatment procedures for hepatocellular carcinoma (HCC), including hepatic resection, transcatheter hepatic artery embolization and percutaneous ethanol injection. However, Some patients could not receive these treatments because of the liver dysfunction and the location of the tumors. In such cases, we have developed the microwave coagulation therapy (MCT) for HCC. From June 1992, 53 patients have received MCT : 8 cases received laparoscopic-MCT (L-MCT), 19 cases received open-MCT (O-MCT) and 26 cases received percutaneous-MCT (P-MCT). Liver function of L, O-MCT patients was worse than that of patients who received partial resection of the liver. The actual and disease-free 3-years survival rate were identical between the patients who received L, O-MCT and those who had partial hepatectomy. Out of 13 cases with tumor size greater than 2 cm in diameter receiving P-MCT, 7 cases should remaining enhanced area by a follow up dynamic CT, although none of 13 cases with tumor size less than 2 cm in diameter should enhancement. MCT is a possible choice of treatment for some HCCs.
We performed hepatectomy of the main tumor combined with intraoperative microwave tissue coagulation (MTC) therapy for the daughter nodule when these daughter nodules, that were not preoperatively detected, were pointed out by the intraoperative ultrasonography and radical resection could not be performed. The prognosis and quality life of 12 cases, who were treated with such combination therapy, were relatively good. Hepatectomy combined with MTC therapy might be useful for patients with advanced hepatocellular carcinoma based on liver cirrhosis, who could not be tolerant of radical operation.
We reported eight liver cancers four hepatocellular carcinoma and four metastatic cancer who had recieved microwave coagulo-necrotic therapy (MCN). The indication of MCN was unresectable tumors and/or less than 4 cm in diameter. In cases of metastatic liver cancer, it was obligatry essential that the primary lesion had been resected radically. The efficacy of MCN was classified into four categories : excellent, good, fair, and poor. In the group of excellent category, no local reccurence was obserbed after MCN. We could recomfirm that the MCN was very effective and minimally invasive one for patients with both hepatocellular and metastatic liver cancer.
The incidence and modality of postoperative complications related to the use of microwave tissue coagulator (MTC) or other methods in hepatectomy for hepatocellular carcinoma were retrospectively analyzed in 109 patients. The incidence of surgical manipulation-related complications was 6/92 (9.7%) for MTC employing hepatectomy and 9/47 (19.1%) for hepatectomy with other methods. The complications in MTC employing hepatectomy included 1 stump abscess, 2 subphrenic abscess, 2 bile leakage from the resection stump, 1 stump hemorrhage, while those in hepatectomy utilizing other methods were 2 stump abscess, 2 subphrenic abscess, 3 stump bile leakage, 2 immediate postoperative stump hemorrhage. There was no increased tendency nor specific modality of postoperative complication occurring in MTC employing hepatectomy.
Percutaneous ethanol injection (PEI) was applied to 258 lesions in 205 patients with hepatocellular carcinomas 3 cm or less in diameter (small HCC) between Aug. 1983 and Aug. 1995. In 118 (95.9%) main lesions of 123 HCC patients who underwent a contrast enhanced CT before and after PEI, CT showed HCC lesions changed to avascular ones both early and late phases that indicating complete necrosis. The 1-, 3- , 5-, and 7-year survival rates after PEI were 97.4%, 67.2%, 47.3% and 24.5% respectively. Recurrence occurred in hepatic areas different from the original lesion in 24.4% in one year and 64.3% in three years after PEI. For such recurrence PEI alone was then repeated in 51.7% of 120 patients. Because of anti-tumor therapeutic effect, minimal damage to the liver, PEI might be considered as a viable alternative to surgery for most patients with small HCC.
Hemostasis by microwave coagulation has spread worldwide since 1981. Now, this excellent method has been applied to the hemostasis of bleeding from many gastrointestinal diseases even in lower intestinal bleeding or bleeding from esophageal varices. In this report, we evaluated the effect of endoscopic microwave coagulation method for the treatment of upper gastrointestinal bleeding. Temporary hemostasis was obtained in all patients. Complete hemostatic effect was obtained in 97% all of patients. This method was effective in all patients of arterial bleeding. The effect of hemostasis was almost equal in patients with and without complications. Endoscopic microwave coagulation method is effective for upper gastrointestinal bleeding especially in patients with arterial bleeding and complications.
From April 1988 to June 1995, we performed microwave regional coagulation therapy (MRCT) with suspicious recurrent bladder tumors, immediately after bladder biopsy under epidural anesthesia 24 times in 17 outpatients. Of the 17 cases, both clinical and pathological examinations revealed that 14 cases were of recurrent, superficial bladder cancer. Tumors were completely eradicated both endoscopically and histologically in all patients. Four had a slight hematuria or lower abdominal pain after MRCT. These complications, however, improved in a few days after medication. Furthermore, the cost of outpatient MRCT was one third that of the transurethral resection of bladder tumor in hospital treatment, which required a 3 day admission. Outpatient MRCT could be one of several safe and useful treatments for patients with recurrent bladder cancer.
Recently I reported about several microwave electrodes for ENT diseases. Among of those instruments, by large and small tow double-needle electrodes, nasal polyps 33 cases (35 sides) and hypertrophied turbinates 20 cases (26 sides) were treated on between August 1990 and July 1994. After that these electrodes conked out on account of overheating, so I made again new 3 types : 5 mm long, 1 mm, 2 mm and 3 mm wide. Microwave coagulation is performed by puncturing the morbid growth with the 2 needles. One round of coagulation lasts for 1-3 seconds at 30-40W. And this method is also used for other diseases in this area together with other electrodes.
A 71-year-old woman was admitted to our hospital with dysphagia. X-ray examination revealed an 11 cm-long stenosis of the esophagus, and a biopsy specimen revealed poorly differentiated squamous cell carcinoma. The patient underwent 60 Gys of radiation therapy for primary esophageal tumor. Endoscopic and X-ray examinations revealed a significant diminution in the lesion, so she was discharged. Six months later, the patient returned to our hospital with dysphagia. We applied endoscopic microwave coagulation therapy (EMCT) for the esophageal stricture. After 4 sessions of EMCT therapy, significant improvements were seen in symptoms and in endoscopic and X-ray findings. We concluded that EMCT can be used accurately and safely as palliative treatment for malignant stricture of the esophagus.
We report a case of biloma which was developed by communication between the biliary tract and the retention cyst in the post hepatectomy patient, following percutaneous microwave coagulation therapy (MCT) for hepatocellular carcinoma (HCC). The patient developed retention cyst after posterior segmentectomy of the liver for hemangioma in 1986. About 7 years later, HCC of 2 cm in diameter was revealed adjacent to the cyst. Although surgical resection was technically possible, the patient chose to undergo MCT. He had an attack of fever approximately one year after MCT. Investigation revealed biloma that was developed from retention cyst by communication between the biliary tract and the cyst. Then we performed surgical resection of the biloma together with the recurrent HCC neighboring the cyst.
Recurrent lesion of hepatocellular carcinoma (HCC-R) just below the dyaphragm which resists to transcatheter hepatic arterial embolization therapy (TAE) is also difficult to perform percutaneous ethanol injection therapy (PEI) according to its anatomical relationship. Recently, we have performed thoracoscopic and open thoracotomic microwave coagulo-necrotic therapy (MCN) on this type of HCC-R and successfully suppressed the proliferation of the tumor. The case was 62 years old man being HBV carrier. In June 1992, subsegmentectomy of the liver (S6) was performed for the HCC with liver cirrhosis. In August 1993, HCC-R was pointed out on S7, however, the resection of this lesion was considered to be impossible because of inadequate hepatic functional reserve. Therefore, TAE was performed and the control of tumorous proliferation was found to be incomplete. The third TAE performed in July 1994 was failed because its feeding right hepatic artery, which branched from superior mesenteric artery, was occulded by preceding TAE. In August 1994, after the identification of tumor-occupied lesion by the CT imaging, thoracoscopic MCN was performed for this intractable recurrent tumor. Preoperative intrathoracic 3-D reconstraction image produced by helical CT scan was useful for detection of infra-diaphragmatic tumorous location. However, an additional damage due to MCN may be induced on the right cardiac atrium and inferior vena cava which is neighboring the tumor, and thus the control of the tumor was still incomplete. In December 1994 another new HCC-R lesion was found near the previous treated part on S7, and open thoracotomic MCN therapy was performed again in June 1995. The follow-up CT image showed an adequate control of this tumor after three weeks of this operation. MCN is very useful in treating unresectable HCC, and it is suggested the possibility making up defects between surgical hepatic resection and other interventional therapy.
Microwave coagulonecrosis (MCN) was performed percutaneously for hepatocellular carcinoma (HCC), after transcatheter arterial chemoembolization (TACE). (Case-1) The patient was a 55-year old man with type-B chronic hepatitis for 10 years. Tumors were found in S7 (3 cm) and S8 (4 cm) segment of liver. Percutaneous MCN was performed 4 and 6 weeks after lipiodol-TAE. CT-guided percutaneous transpulmonary MCN was useful for the HCC in S7, which was not revealed with ultrasonography. Posttreatmental hemopneumothorax did not require any treatment. (Case-2) The patient was a 69-year old woman with type-C liver cirrhosis. After TAE, CT-guided percutaneous transthoracic MCN were done for the HCC (2 cm) in S8-4. In order to avoid the pulmonary injury, right pneumotorax was prepared deliberately. The course of two patients after the treatments was very excellent. The complementary therapy of TACE and percutaneous MCN is minimally invasive and may be very effective treatment of HCC.