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Biomedical subjects

S Asaki

Publications and source records attributed to S Asaki.

At least 73 records · Page 4Linked to original sources
PubMed1984

Diagnosis of submucosal tumor by injecting a water soluble contrast medium: development pattern and growing of tumors.

With the application of our endoscopical method of contrasted X-ray imaging, gastric submucosal tumors were studied with chief regards to their modes of growing up and patterns of development. It has become known that, of extra-gastric developing tumors, larger ones tend to show Pattern IVa and smaller ones Pattern IVb. Generally, the tumors showed a tendency of becoming larger in older patients. Periodical checking disclosed about 15% of the tumors growing larger with the lapse of time. It has been surmised that as tumors grow up, their development possibly turns from intra-gastric to intramural and mingled in pattern. Their modes of growing could be classified as follows: Abruptly growing large at a certain time and then remaining without notable changes, step-by-step enlarging, and gradually growing up straight forwardly with years.

Adult↗
PubMed1984

Diagnosis of submucosal tumors by injecting a water soluble contrast medium: judgement of tumor developing pattern and endoscopic lumpectomy.

With the remarkable increases in the number of cases of endoscopical removal of submucosal tumors spurred by the application of high-frequency current, it has become more and more important to apply beforehand some reliable methods like ours to differentiate between tumors and other tumescent lesions due to extra-gastric pressure similar in configuration to tumors and also to confirm the development patterns of tumors either intra-gastric or extra-gastric. Such preparatory arrangements seem indispensable to minimize the risk of perforation incidental to the endoscopical treatment of tumors. To cope with another danger of major bleeding following tumor resection, securing on hand an effective hemostatic is indispensable as well. In our care of the patients after their undergoing endoscopical lumpectomies, we usually subject them to quiet rest and fasting for two or three days; then when they are to resume a regular diet, we endoscopically examine them before and after each meal to confirm the presence or absence of bleeding. In 12 subjects of this series treated with our routine and finally with lumpectomies for gastric submucosal tumors, no serious adverse reactions developed.

Adolescent↗
PubMed1984

Problems in localization of bleeding sites and the incidence of varicose rupture in emergency endoscopy.

An investigation was made for problems involved in identification of bleeding sites and the incidences of bleeding from esophageal and gastric varices in emergency endoscopy within 24 hr after overt gastrointestinal bleeding. Varices or ulcers are not always the source of bleeding, and endoscopic examinations should be performed early after the onset of bleeding to make correct identification of the bleeding site. For such purposes, aspiration using endoscopy, washing under direct observation using a teflon tube and changing of body posture were found effective. During the 6 years from 1977, bleeding from the esophageal or gastric varices was detected in 4 cases out of 30 cases of esophageal or gastric varices which had undergone emergency endoscopy for overt bleeding. After June, 1979, when hemostatic measure using pure ethanol was applied actively, bleeding from esophageal or gastric varices was observed in 4 cases (2.5%) out of 160 cases. Results of the present emergency endoscopy revealed that the incidence of rupture of varices was not so high as had been expected conventionally.

Emergencies↗
PubMed1983

Endoscopic control of gastrointestinal hemorrhage by local injection of absolute ethanol: a basic assessment of the procedure.

To investigate the hemostatic mechanism of local ethanol injection, ethanol was injected into the gastric mucosa of five adult mongrel dogs and one guinea pig and histologic changes at acute and healing stages were followed. Following a local injection of absolute ethanol, the blood flow in small vessels at the site of injection became instantaneously arrested. Histopathologically, thrombosis of blood vessels in the mucosa and submucosa with edema, predominantly submucosal, was found 10 min after the ethanol injection. There was little or no inflammatory cell infiltration in the injected region. By 4 days after the injection, the base of the formed ulcer became stabilized with a uniform white coating, which, microscopically, was mainly composed of a thick layer of necrotized mucosal tissue. Ethanol showed fixative activity when applied to tissues at concentrations of greater than or equal to 20% although an ethanol concentration of at least 70% was required to accomplish adequate tissue fixation. With 95% or lower concentrations of ethanol, dehydration of tissue was insufficient, and hemostasis due to local vasoconstriction was less conspicuous than with absolute alcohol. Nevertheless, a fixative effect with consequent degeneration and necrosis of cells and secondary thrombosis was evident even at these ethanol concentrations. In patients treated with this hemostatic procedure, exposed blood vessels in the gastric ulcer became necrotized and corroded by fixation with injected absolute ethanol and disappeared from the base of the ulcer within 24 hr as seen in the animals.

Adult↗
PubMed1983

Endoscopic hemostasis of gastrointestinal hemorrhage by local application of absolute ethanol: a clinical study.

The procedure of endoscopic hemostasis with topical injection of absolute ethanol has been developed and applied since 1975 for the control of postoperative hemorrhage associated with diathermic polypectomy. Since June 1979, upper gastrointestinal hemorrhages other than varices have also been subjected to this procedure. This method is based on the principle of dehydration and fixation of the tissue with absolute ethanol. In this procedure, the bleeding vasculatures are dehydrated and fixed with consequent vasoconstriction and necrosis of the vascular wall including its endothelial lining, thereby thrombogenesis and hemostasis are facilitated. The troubled blood vessels fixed in vivo are disintegrated and disappeared. Rebleeding from the ulcer has been extremely rare with this method since the necrotized tissue seldom defoliates but often constitutes a part of the white coating and protects the base of ulcer. Treatment by this method has been successful in all 23 cases of upper gastrointestinal hemorrhage associated with endoscopic diathermy, and none has developed rebleeding. The hemostasis has also been successful in 51 cases (72 hemorrhagic lesions) with fresh blood clots adhering to the lesion, exposed blood vessels in the lesion or an actively bleeding lesion out of 126 cases referred for emergency endoscopic examination because of upper gastrointestinal hemorrhage during the 3-year period from June 1979 to May 1982. After hemostasis, however, 3 patients received an elective operation and one patient was also operated due to perforation of the gastric wall. Rebleeding occurred in 3 cases more than a week after the hemostasis; one of these was the above-described operated case of perforation. The rebleeding occurred in stress ulcers following surgery for femoral fracture. The other two were at the terminal stage of malignancy and complicated with DIC respectively. Of the patients treated by this method, 8 died by causes other than gastrointestinal hemorrhage. All the rest of 39 cases attained cure of ulcer by the non-surgical treatment alone.

Adult↗
PubMed1983

Combination therapy of gastric atypical epithelium and elevated type early gastric cancer with high frequency current and laser.

A total of 11 lesions, consisting of elevated type early gastric cancer and atypical epithelium of more than 2 cm in diameter which were found in 9 cases, were jumbo biopsied using high-frequency current and the specimens obtained were examined histologically. Based on the results, the final diagnosis was established in terms of the benign or malignant nature of the lesions, some modifications were made in the irradiation method in accordance with the depth of invasion of the gastric cancer, and the adequacy of the irradiation therapy was examined. Then, the remaining tumor was irradiated with laser. This combination therapy of high frequency current and laser can make up for the drawback associated with laser therapy which does not permit collection of specimens for pathohistological study.

Adenocarcinoma↗
PubMed1983

Ultrasonic endoscopy.

With the use of a linear scan type ultrasonic endoscope, the possibility of gastric fiberscopy with ultrasonic procedure in the estimation of the extent of deep infiltration of gastric cancer and in the transgastric diagnosis of pancreatic tumors was studied. Results revealed that the echogenicity of the tumor was more clearly recorded by ultrasonic endoscopy than routine ultrasonography taken via the abdominal wall. With improvements in both the probe and manipulation technique, the device is expected to achieve far-reaching contributions to the diagnosis of the deep invasion of gastric cancer and small-sized pancreatic tumors.

Adult↗
PubMed1982

Endoscopical polypectomy using high frequency current: double-snare method of polypectomy for prevention of incidental bleeding and perforation.

The author developed a double-snare method or high-frequency-current-applied endoscopical polypectomy (double-snare polypectomy, for short). Since 1975 the double-snare polypectomy was applied to 40 gastric polyps (36 patients), over 15 mm in the largest diameter. 7 massively hemorrhaged cases after polypectomy were treated by hemostatic methods, such as electrocoagulation and pure ethanol injection. This method was warranted as a reliable formula for a risk-less resection of large polyps without causing persistent major bleeding or fateful perforation.

Adult↗
PubMed1982

Diagnosis of submucosal tumors by injecting a water soluble contrast medium: basic research and imaging of tumors.

With the aim of adequately distinguishing gastric submucosal tumors from other lesions such as gastric polyps, gastritis, and protuberances due to extragastric pressure, a new method was developed. A water soluble contrast medium is endoscopically injected into a submucosal lesion followed immediately by the application of roentgenography, thereby obtaining X-ray pictures of the lesion through frontal and lateral projections. Since the contrast substance is water soluble, the method can visualize submucosal microchanges. Highly diffusible, the substance usually has a fading time of about 40 min, the present method is convincingly free of danger. This paper provides the results of basic research performed using adult mongrel dogs together with some comments on the applicability of the method in clinical use.

Adult↗
PubMed1982

Diagnosis of submucosal tumors by injecting a water soluble contrast medium: diagnosis of tumors and clinical presumption of their development patterns.

So far there have been no clinical methods claiming reasonable estimation of the patterns of submucosal tumors. In an attempt to shed some light on this difficult task, we have elaborated an endoscopical procedure; injecting a water soluble contrast medium into the submucosa and immediately applying roentgenography, we have obtained an X-ray image of the object lesion, visualizing its frontal and lateral aspects, which could help us outline the intramural characteristic of the tumor, informing us of its development mode. The device suggests its far-reaching contributions to the possible diagnosis of submucosal tumors prior to treatment and confirmation of their indications adequate for endoscopical treatment. Our method may potentially represent an ideal step to the consummation of endoscopic treatment of tumors, the success of which is dependent on the prevention of major bleeding and perforation.

Adolescent↗
PubMed1981

Modeling of digestive tract lesions using silicone rubber RTV (KE-12).

In order to produce life-size models of digestive tract lesions, we applied silicone rubber RTV (KE-12) over the surface of the resected fresh, half-fixed or completely-fixed specimens to achieve their impressions. Into these impressions, super-hard plaster, acrylics and lysine base were separately poured, with the resultant casts realizing faithful replicas of the original patterns, finely reproducing their mucosal micro-structures. A photofluorogram of the silicone rubber pattern taken by using softex could reveal roentgenographic micromucosal features on a single plane. Clinically, endoscopic casting of lesions in similar procedures could produce their models, providing data available for estimation of the size and depth of an ulcer. Our method would be of help in dynamical pursuit of digestive tract lesions, as well as for comparison of the vital realities of lesions and their histopathological findings. The method may further contribute to reducing the dosage of x-ray bombardment in gastric fluoroscopy.

Animals↗
PubMed1981

Tissue solidification in coping with digestive tract bleeding: hemostatic effect of local injection of 99.5% ethanol.

Tatsuka et al. reported a local injection of 95% ethanol as a new endoscopic treatment of gastric protuberant lesions. In this method, the present author discovered that 99.5% ethanol injection has an excellent hemostatic effect. The author injected 99.5% ethanol into the cut-end of the stalk of 7 massively hemorrhaged cases encountered while performing double snare polypectomy. In all cases, the hemorrhage stopped within 5 or 15 min. In 9 patients with hemorrhagic gastric or duodenal ulcer who were judged at emergency endoscopic examination as needing some hemostatic treatment, an injection of 99.5% ethanol into the bleeding site achieved a satisfactory hemostasis in all of them. Ethanol injection into the surrounding tissue close to the bleeding vessels, a few injecting sites selected usually at 1 to 2 mm away from the bleeding vessels, 0.1 to 0.2 ml a time, could instantly suppress even the pulsatile bleeding with no hazards. If this method is used carefully with endoscopic skill, this should become the first choice for the gastro-intestinal hemorrhage except varices.

Adult↗
PubMed1981

Endoscopic gastric polypectomy using high frequency current: its significance for total biopsy of gastric polyp.

Endoscopic polypectomy using high frequency current was performed for 281 out of 345 gastric polyps (230 cases), while the remaining 64 small polyps were cauterized. Histopathologic examinations carried out in 274 out of the 281 polypectomized polyps confirmed gastritis polyposa in 41 lesions, hyperplastic polyps in 216 including 3 cases of neoplasm, atypical epithelium in 4, submucosal tumor in 2, and polypoid cancer in 1. This procedure of endoscopic polypectomy has proved to enable histologic examination of a polyp as a whole, and to allow a highly risk-free endoscopic treatment of polyps. In the currently observed 216 hyperplastic polyps, 3(1.4%) were found to have neoplastic changes.

Endoscopy↗