[Percutaneous placement of intraluminal stent-graft for aortic dissection: experimental study].

Highly porous fabric vascular grafts fabricated of ultrafine polyester fibers (UFPF-graft; porosity, 7,000 ml, 9,000 ml, 11,000 ml at 120 mmHg) were attached between two Gianturco stents connected with two stainless steel struts. UFPF-grafts with two Gianturco stents were placed into the aortas of six adult mongrel dogs without firm contact with the luminal surface. From two days to four months after placement, all the UFPF-grafts were completely sealed with fresh thrombus or neointima. Within two months, complete endothelialization was observed on both surfaces of the neointima. In three dogs, aortic dissections were created experimentally. Then an UFPF-graft (porosity, 9,000 ml) with two Gianturco stents was placed at the site of entry of the dissection, followed by additional Gianturco stents to expand the UFPF-graft. X-ray angiography showed that the entries were closed immediately after placement, and false lumens disappeared within one hour after placement. These results indicated that the method has the possibility of treating aortic dissection with complete sealing of the fabric by the neointima.

Intraarterial occlusion by radiofrequency.

Arterial occlusion using radiofrequency energy was performed. The length of the noninsulated part of the guidewire was 10 mm and the duration of radiofrequency supply was 20 s. Animal experiments were carried out in 17 canine arteries; 4 out of 6 arteries less than 2.3 mm in diameter were completely occluded during the 20 s radiofrequency supply. A clinical application was also successfully performed without any complications. Arterial occlusion with radiofrequency can be applied to vessels less than about 2 mm in diameter.

[Preliminary report on the usefulness of 123I-IMP scintigraphy in distant metastases from hepatocellular carcinoma: except for bone and lung metastases].

N-isopropyl-p-[123I] Iodoamphetamine (IMP) scintigraphy was performed in 10 lesions of metastatic hepatocellular carcinoma. Five of 10 lesions (50%) were detected with planar images, which was superior to the 2 of 8 lesions (25%) detected with 67Ga-citrate (Ga) scintigraphy. The positive ratio was increased to 83% (5/6) with SPECT. Thus our findings suggested that IMP could compensate for Ga scintigraphy in detecting distant metastases of hepatocellular carcinoma.

[99mTc-pertechnetate scintigraphy in three cases with soft tissue tumors].

Three soft tissue tumors were studied with 99mTc-pertechnetate scintigraphy, 67Ga-citrate scintigraphy and MRI. These tumors included schwannoma, neurofibromatosis and malignant fibrous histiocytoma. On 99mTc-pertechnetate scintigram all patients showed more increased accumulation corresponding to the tumor than on 67Ga-citrate scintigram. In conclusion, 99mTc-pertechnetate scintigraphy may be useful in detection of soft tissue tumors.

[Percutaneous radiofrequency coagulation therapy for liver tumor: experimental study].

We invented a newly devised local thermal therapy using radiofrequency energy for treating liver tumors. This method was investigated for evaluating its safety and effectiveness. In vitro study, the maximum size of coagulated albumen was 5.5 to 6.2mm in diameter, and 9.8 to 11.3mm in length. In vivo study using rabbit's liver, the range of coagulated tissue by radiofrequency energy was localized around the tip of the needle. Percutaneous radiofrequency coagulation therapy will be the effective therapy for liver tumor regardless of tumor vascularity.

The potential use of I-123 IMP scintigraphy for pelvic bone metastases in hepatocellular carcinoma. A comparison with Ga-67 scintigraphy.

Conventional bone scintigraphy is often inconclusive in detecting bone metastases of hepatocellular carcinoma, suggesting the necessity of alternative scintigraphic agents. In this study, the diagnostic value of I-123 IMP scintigraphy was evaluated in 8 patients with 12 pelvic bone metastases from hepatocellular carcinoma, then compared with Ga-67 scintigraphy. Eleven of 12 lesions (91.7%) were detected by I-123 IMP scintigraphy; Ga-67 scintigraphy visualized 8 lesions (66.7%) in the same patient population. I-123 IMP scintigraphy is useful for detecting pelvic bone metastases of hepatocellular carcinoma with less physiologic accumulation in the intestine as compared with Ga-67 scintigraphy.

Clinical experience of 123I-IMP scintigraphy in detecting vertebral bone metastases of hepatocellular carcinoma. A comparison with bone scintigraphy with 99mTc-MDP.

Although bone scintigraphy with 99mTc-MDP is a sensitive diagnostic method to detect bone metastasis, it is not specific for malignancy. A radioactive substance which accumulates specifically into metastatic lesions should be of value. 123I-IMP and bone scintigraphy with 99mTc-MDP were consecutively performed in patients with vertebral bone metastases from hepatocellular carcinoma and lumbar spondylosis deformans in a 7-day interval or shorter. The intensity of uptake was compared. Eighteen of the 20 metastatic lesions (90%) were classified as increased uptake areas in 123I-IMP scintigraphy. MDP-scintigraphy disclosed 16 metastatic lesions (80%), 9 as "hot" lesions (56%) and 7 as "cold" lesions (44%). 123I-IMP scintigraphy was negative in all 12 lesions of lumbar spondylosis deformans. Compared to MDP-scintigraphy, 123I-IMP scintigraphy was more sensitive in detecting vertebral bone metastases of hepatocellular carcinoma with smaller rates of false-positive and false-negative findings.

Repeated arterial infusion chemotherapy for inoperable hepatocellular carcinoma using an implantable drug delivery system.

Arterial infusion chemotherapy has become one of the major treatments for malignant tumors. Since 1988, we have attempted repeated arterial infusion of anticancer drugs using an implantable drug delivery system in 68 patients who had inoperable hepatocellular carcinoma (HCC). Most of our patients could not undergo transcatheter arterial embolization (TAE) because of extreme tumor extension and/or accompanying advanced liver cirrhosis. In most patients we implanted a 5-F catheter via the femoral artery nonsurgically and connected it to a subcutaneously implanted drug delivery system without any difficulty. The treatment consisted of weekly or biweekly intrahepatic one-shot administration of anticancer drugs. As one therapeutic regimen, epirubicin was given alone. Other regimens consisted of combined chemotherapy using two or more of the following drugs: mitomycin C. Adriamycin, 5-fluorouracil, cisplatin, and epirubicin. In some cases, these drugs mixed with Lipiodol were given for targeting and slow release in the liver. The response rate (CR+PR) of the cases was 25.0%. The median survival period was 389.9 days. The 6-month, 1-year, and 2-year survival rates were 75%, 45%, and 17%, respectively. There was no severe side effect or complication except arterial occlusion that precluded further infusion chemotherapy. We think that the implantable drug delivery system will contribute not only to improved therapeutic efficacy for inoperable HCC but also to an improved quality of life for the patients.

[Quantitative regional cerebral blood flow study with 123I-IMP in patients with dementia and in patients with poor activities of daily living].

N-isopropyl-p[123I]iodoamphetamine (123I-IMP) SPECT and quantitative regional cerebral blood flow (rCBF) studies were performed in 111 patients with cerebral disorders. Continuous arterial blood sampling method based on the microsphere model was used as a quantitative rCBF measurement. We evaluated rCBF in patients with dementia and also in patients with poor activities of daily living (ADL). Patients with dementia showed significant reduction of mean CBF in contrast to patients without dementia. Significant decrease of rCBF in the bilateral frontal cortex, parietal cortex and basal ganglia and the right temporal cortex were found in demented patients. Although patients with vascular dementia showed decreased rCBF in bilateral basal ganglia, demented patients with Parkinson's disease showed no significant reduction of rCBF in any regions. Patients with poor ADL showed decreased rCBF in all brain regions. And particularly frontal and basal ganglionic defects were most pronounced. Patients with poor ADL resulted from cerebral infarction showed significant decrease of rCBF in bilateral basal ganglia. However, there was no significant correlation in Parkinson's disease between ADL and rCBF. The rCBF measurement with 123I-IMP is useful for clinical evaluation of demented patients and patients with poor ADL.

[Clinical usefulness of 123I-IMP scintigraphy in the diagnosis of bone metastases from hepatocellular carcinoma: comparison with 99mTc-MDP bone scintigraphy].

The diagnostic value of N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) scintigraphy was evaluated in 12 patients with 20 bone metastases from hepatocellular carcinoma, in comparison with 99mTc-methylene diphosphonate (99mTc-MDP) bone scintigraphy. Sixteen lesions (80%) were detected by 123I-IMP scintigraphy, whereas four lesions (two lesions in the rib and two lesions after a radiation of 40 Gy) were missed. Of 16 lesions demonstrated as areas of increased uptake in 123I-IMP scan, only eight (50%) showed an increased pattern of uptake in 99mTc-MDP bone scintigraphy. In conclusion, 123I-IMP is a promising radiopharmaceutical for the detection of bone metastases from hepatocellular carcinoma.

[Experimental study with radiofrequency-induced thermal arterial occlusion].

A preliminary experiment on arterial occlusion using radiofrequency energy was performed. A surgitron FFPF was used as a radiofrequency power generator, and a Tracker 18 catheter was used as a probe insulator. A 10 mm length of the guide wire protruding from the tip of catheter was used as the radiofrequency probe. To examine the safety of this procedure within the vessels, the following experiments were performed. A 2.5 mm diameter dimple at the surface of a sausage was filled with human blood. We inserted various lengths of non-insulated guide wire into the dimple and supplied radiofrequency power. We then measured the time until air bubbles appeared in the dimple. With a 10 mm length of non-insulated guide wire, this took over 30 sec. Animal experiments were carried out in 17 canine arteries. The diameter of these arteries ranged from 1.3 to 3.7 mm. Before the procedure, angiograms were taken using a 5 F catheter from the right femoral artery. A tracker 18 catheter and guide wire were inserted to the target position co-axially. The guide wire was attached to the radiofrequency generator. The tip of the guide wire functioned as the convergence point of an electrically conducting induced current. Treatment was performed by supplying radiofrequency power of various durations.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of tuberculous bronchial stenosis with expandable metallic stents.

Gianturco expandable metallic stents were placed in 5 patients with dyspnea on exercise due to tuberculous bronchial stenosis. The stents were placed after dilatation with a 10-mm diameter high pressure balloon catheter. In all 5 patients, obstructive changes disappeared following the procedure, and dyspnea on exercise improved markedly. No complications related to the procedure were encountered. At follow-up during a period of up to 38 months, 2 patients showed bronchial restenosis at 11 and 17 months, respectively, after stent placement. Restenosis by granulomatous tissue was successfully treated by laser ablation. One patient showed slight one-day hemoptysis 26 months after stent placement.

[A study of transsplenic CO2 gas enhanced portal angioechography].

Transsplenic CO2 gas enhanced portal angioechography was examined. The spleen of three dogs was punctured by 23 gauge needle with two side holes. From 5 ml to 20 ml of CO2 gas was injected into the splenic vein via the splenic parenchyma, and elevation of echo level of the liver was observed. Hematoma was not seen at the site of puncture. Good image was obtained in the case of 5 ml CO2 injection. In one dog with pseudotumor in the liver, the hyperechoic tumor changed into negative enhanced nodule after CO2 gas enhancement. Transsplenic CO2 gas enhanced portal angioechography is thought to be useful to evaluate hepatic tumors.

[Repeated arterial infusion chemotherapy for inoperable hepatocellular carcinoma using implantable drug delivery system].

We performed a clinical evaluation of repeated arterial infusion chemotherapy using an implantable drug delivery system for 41 patients with inoperable hepatocellular carcinoma (HCC). About half of our patients could not undergo transcatheter arterial embolization (TAE) because of extreme tumor extension and/or accompanying advanced cirrhosis. In most patients we implanted a 5 Fr. catheter non-surgically and connected it to an implanted injection port through a subcutaneous tunnel. The treatment schedule was weekly or biweekly intrahepatic one-shot administration of mitomycin C, adriamycin, 5-fluorouracil and epirubicin. The response rate (CR + PR) was 24.4%. The median survival period was 401.1 days. The 6 month, 1-year and 2-year survival rates were 73%, 48% and 24%, respectively. There were no severe side effects nor complications. The implantable drug delivery system will contribute not only to improved therapeutic efficacy for inoperable HCC but also improve the quality of life for patients.

[Experimental study of water jet angioplasty].

A newly invented angioplasty by using water jet energy was investigated for evaluating its safety and effectiveness in 3 dogs. The water jet was produced from a small tip nozzle (0.2 mm in diameter) of catheter by injecting 20 ml of diluted contrast medium. By using this method recanalization of femoral arterial occlusion produced by fresh thrombi was achieved in all 3 dogs. Post recanalization angiography showed no apparent small vessel occlusions. Injection apart more than 5 mm from the inner surface of human aorta provoked no apparent changes histopathologically. Water jet angioplasty may be useful in treating vascular occlusive disease.

Application of expandable metallic stents to the venous system.

Expandable metallic stents were successfully introduced in 12 patients; 6 with superior vena cava (SVC) obstruction due to tumor invasion or lymph node metastases, 3 with inferior vena cava (IVC) obstruction or stenosis due to lymph node metastases or hepatic tumor, one with common iliac vein (CIV) obstruction due to lymph node metastases, one with idiopathic obstruction of the hepatic IVC and Budd-Chiari syndrome, and one with CIV obstruction following a dialysis shunt. The length of the lesions was between 2 and 15 cm. Multiple (2-7) stents in tandem were inserted percutaneously from a femoral venous approach through a 12 to 16 F (4.0-5.3 mm) Teflon sheath. Postoperatively, all 12 patients became free from symptoms such as SVC syndrome or IVC syndrome. In 11 patients, the symptoms did not recur during the follow-up periods of 1 to 21 months.

[Usefulness of dopamine administration after transcatheter hepatic arterial embolization based upon portal hemodynamics].

We evaluated usefulness of dopamine administration after transcatheter hepatic arterial embolization (TAE) for the prevention of hepatic failure in experimental and clinical study. In experimental study we measured portal blood flow in dogs with doppler catheter before and after TAE. Administration of dopamine after TAE increased portal blood flow significantly. In a clinical study the usefulness of dopamine was investigated in a clinical laboratory test. It revealed that serum GOT and GPT improved earlier with dopamine administration after TAE. In conclusion dopamine increased portal blood flow and decreased hepatic parenchymal damage after TAE.

[Clinical experience of expandable metallic stent placement for malignant biliary obstruction].

Expandable metallic stents of modified Gianturco design were used in nine cases of malignant biliary obstruction. Stents were placed through a percutaneous transhepatic approach without any severe complications. Initial patency was obtained seven of nine patients. Of these seven patients, recurrent jaundice was observed in three within four weeks. One patient had recurrent stenosis after four months due to ingrowth of the tumor. Although the expandable metallic stent offers several theoretical advantages over currently available stents, a disadvantage is that tumors may grow through the spaces between the legs of the wire or grow over the stent. We found that multi-modal treatment combined with radiation therapy was indispensable to maintain the patency of the stent in malignant biliary obstruction.

[An animal experiment on arterial wall reaction to stents coated with gold, silver and copper].

Expandable metallic stents coated with gold, silver, and copper, and bare stainless steel stents were implanted into the abdominal aorta of eight dogs to determine their effect on the vessel wall. The animals were observed for two weeks. Abdominal angiograms were taken every week. The dogs were then killed for macroscopic and histopathological examination. The results were as follows. (1) The stents coated with gold and the noncoated stainless steel stents showed less histopathologic change than the other stents. (2) The stents coated with copper were associated with severe erosion of the vessel wall and marked thrombus formation.