Satoshi Sawada

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.

Reaction of the aortic wall to six metallic stent materials

RATIONALE AND OBJECTIVES We investigated the effects of various metallic stents on the aortic wall. METHODS The wires of Gianturco-type expandable metallic stents were plated with gold, silver, or copper or coated with Teflon or silicone. Stents were inserted into the aortas of 15 adult mongrel dogs. The time course of radiologic, macroscopic, and histologic changes in the aorta at the site of the stent was investigated at 1, 2, and 4 weeks after implantation. RESULTS The gold-plated stent appeared to produce fewer macroscopic and histopathologic changes in the aorta than the other types of stents. The neointima was thinnest with gold (83.9 +/- 40.3 microns), followed by stainless steel (103.6 +/- 57.0 microns), Teflon (115.0 +/- 30.2 microns), silicone (209.6 +/- 25.9 microns), silver (228.6 +/- 33.8 microns), and copper (unmeasurable). With the copper-plated stent, the aorta suffered severe erosion of the vessel wall, marked thrombus formation, and aortic rupture. CONCLUSION Gold is a useful intravascular material because it reacts only minimally with the vessel wall.

Treatment of Takayasu's aortitis with self-expanding metallic stents (Gianturco stents) in two patients

Gianturco self-expanding metallic stents were successfully placed to treat incomplete balloon dilatation of the abdominal aorta in 2 patients with Takayasus aortitis. In 1 case eleven 1-cm long, 1-cm diameter stents were inserted in tandem to bridge a long stenosis. In the other patient, four stents 1.5 cm long, 1.5 cm in diameter were inserted in tandem to bridge what had been a complete occlusion prior to balloon angioplasty. Clinical symptoms, as well as angiographic findings, improved significantly after placement of the stents. The patients underwent repeat aortography at 10 and 8 months, respectively, and were followed clinically for a total of 18 months and 15 months, respectively, without clinical evidence of deterioration. Our results show the usefulness of expandable metallic stents in the treatment of aortic stenosis due to Takayasus aortitis that remains unresponsive to balloon dilatation.

Prevention of Gastric Complications in Hepatic Arterial Chemoembolization Balloon Catheter Occlusion Technique

Gastric complications may be a problem in transcatheter arterial chemoembolization, if the right gastric artery branches distally from the proper hepatic artery or its branch, or the accessory left gastric artery arises from the left hepatic artery. We occluded the proper hepatic artery with a balloon catheter to redirect blood flow in these gastric branches toward the liver. This procedure prevented chemoembolic agents from flowing into the gastric branches, and accordingly protected against gastric complications even when chemoembolization was performed by injecting the agents proximally to the gastric branches.

Water Jet Angioplasty — an Experimental Study

The usefulness and safety of water jet angioplasty was studied in vitro, using agar phantom and autopsied aorta, and in vivo in acute and chronic arterial occlusions in mongrel dogs. At an injection rate of 1.0 ml/s, the water jet produced erosion of the agar surface when the distance between the catheter and the agar was 1 mm. With an injection rate of 1.5 ml/s, erosion was produced at a distance of 15 mm from the catheter tip. When the water jet was directed at an arterial wall, intimal ablation and ruptured elastic fibers were found histopathologically. A smaller angle between the vascular wall and the catheter was associated with less vascular damage. In vivo, water jet angioplasty was effective against acute obstructions, but not against chronic obstructions. These results suggest that water jet angioplasty may be effective against arterial obstruction due to acute thrombus.

Endotracheal Expandable Metallic Stent Placement in Dogs

Various types of Gianturco zig-zag wire stent were implanted into the tracheas of 4 dogs to define the suitable characteristics of the endotracheal wire stent in these animals. The stents were constructed of 0.45, 0.40, and 0.33 mm stainless steel wire. The diameter of the fully expanded stents was 3 cm and their lengths were 2, 3, and 4 cm. The 2 cm stent constructed of 0.33 mm wire showed minimum pathologic changes of the trachea of the dog compared to the other stents, and at the same time had a complete covering of ciliated columnar epithelium over the stent surface.

Outcome of localized hepatocellular carcinoma treated with segmental arterioportal chemoembolization

SummaryWhen lipiodol is injected into the hepatic artery at a dose exceeding a certain level, it flows into the portal vein. On the basis of this feature, an emulsion of Adriamycin with lipiodol was injected into a segmental or subsegmental artery such that it was delivered to the portal vein of the same segment, and the artery was then embolized with Gelfoam. This segmental arterioportal chemoembolization (cement therapy) was performed in 50 patients with localized hepatocellular carcinoma. A posttreatment CT scan showed that almost 100% of the lesions were occupied by lipiodol. The cumulative survival values determined for the 50 patients were very high: 83.4% after 1 year and 62.7% after 2 years.

Computed Tomographic Percutaneous Transsplenic Portography

The diagnosis of liver tumors should be utilized for determination of not only the number of lesions, but also their size, segmental location and extent, and the relationship of the mass or masses to the hepatic vasculature. CT during arterial portography (CTAP) is the most sensitive imaging modality for precise diagnosis of hepatocellular carcinoma (1–3, 5). CTAP is thus widely used as a diagnostic imaging technique, particularly for the detection of small hepatocellular carcinomas (4, 6, 8). Conventional splenic portography has been carried out for many years using a wide diameter needle, a large amount of contrast medium and a film-screen system (7). Since the development of arterial portography, fewer splenoportograms have been performed due to the high incidence of bleeding and other complications (7). In this study a 0.6-mm (23 gauge) thin needle was used for splenic puncture and CT was used as a detector instead of a film-screen system. With this technique CT during percutaneous transsplenic portography may be performed on an outpatient basis.

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.

Experience of a small PACS in Tottori University Hospital

Picture archiving and communications systems (PACS) are expected to become feasible as the way of total radiologic image management. As the first step towards computerized image management, we installed an experimental small PACS with a digital optical archive for magnetic resonance and digitized radiographic film images. During the first 10 months of operation, problems were caused by the frequent mechanical troubles on the acquisition devices, impractical schemes for transmission, and troublesome retrieval and display of images. Although some of them have been solved by the improvements of both hardware and software, the mechanical instability of the digitizer and the inadequate operating procedure of the workstation still remain. As to the characteristics of PACS, the capability of access to every achieved radiologic image is the great advantage for us because the image integration has been impossible in the form of radiographic films for the traditional image management system of our hospital. However, the complicated image display procedure with high overheads is far from ideal for radiologists. The efficiency of image display must be increased to the level of a conventional film viewing system. Furthermore, research is needed on the small PACS to get consensus for the acceptance of a more widely implemented system.