Biomedical subjects
Publications and source records attributed to T Iwai.
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A verified case of duplicate origin of the left vertebral artery in association with a large aneurysm arising from the aortic arch immediately distal to the left subclavian artery is presented. An anomalous left vertebral artery arises directly from the aortic arch between the left common carotid and subclavian arteries, and joins with the normal left vertebral artery in the transverse foramen of the fifth cervical vertebra.
From 1974 to 1976, four patients with juxtarenal aortic occlusion were operated upon with no surgical mortality. Thromboendarterectomy (TEA) of the aorta with renal revascularization was performed in one patient, and TEA with grafting in three. Intraoperative renal protection was particularly important, since suprarenal aortic clamping was often required in these cases. Possible renal embolism developed in one patient postoperatively. In order to prevent renal embolism and to minimize ischemic insult to the kidney, the value of the following procedures was stressed; (a) irrigation of aortic lumen with saline after TEA under suprarenal aortic clamping with renal arteries kept occluded, and (b) re-application of aortic clamp below the renal arteries after irrigation. Since the most distal level of occlusive process was the common femoral artery in our series, the patient with this disease entity should be treated more actively.
Degenerative changes of saphenous vein grafts in four preparation media (heparinized whole blood at room temperature and 4 degrees C, and heparinized normal saline at same temperatures) were examined by scanning and transmission electron microscopy and fibrinolytic autography. Following 60--90 min. storage in heparinized normal saline at room temperature, marked morphological changes were present in the media, accompanied by swelling of the endothelial cells, however the tunica media and adventitia were well preserved even after 120 minutes in all of the four preparation media. The decrease in fibrinolytic activity was comparable to the observed morphological changes. In heparinized whole blood at 4 degrees C, degenerative changes were slow and mostly of a slight nature.
A 15-year old female presented with bilateral popliteal artery entrapment syndrome. The left popliteal artery was completely occluded and thromboendarterectomy was performed. Angiography on passive dorsiflexion revealed compression of the right popliteal artery, although it was free of symptoms and of normal caliber. End-to-end anastomosis in the normal anatomical position without division of the medial head of the gastrocnemius muscle was performed on both sides.
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Intermittent claudication is known as a specific symptom in patients with chronic occlusive arterial lesions. Clinically it is important that neurogenic intermittent pseudo-claudication should be differentiated from true intermittent claudication. Nevertheless confusion still exists in differential diagnosis between these two entities. This paper deals with general review of intermittent pseudo-claudication and a particular emphasis is placed on the different concepts of the pathophysiology and the differential diagnosis from the standpoint of vascular surgery. Recently one case of the neurogenic intermittent pseudo-claudication was encountered and presented in this paper.
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We present a 45-year-old male with fibromuscular dysplasia (FMD) of the left brachial artery causing microemboli with digital ischemia. The angiographic diagnosis was medial fibroplasia. Treated with percutaneous transluminal angioplasty (PTA), the corrugated arterial wall was made smooth and production of new thrombi apparently stopped, as 3.5 years after PTA the patient has had no recurrence. Although FMD of the brachial artery is rarely encountered, PTA seems to be an effective treatment as an alternative to surgical interposition grafting.
Changes in myocardial contractility and ventricular myosin isoenzymes were examined during pressure-overloaded cardiac hypertrophy in rats. Effects of regression of cardiac hypertrophy were also examined. Cardiac hypertrophy was induced by abdominal aortic constriction in 7-week-old male Wistar rats. Regression of cardiac hypertrophy was obtained by opening the aortic band. Myocardial contractility was estimated by measuring isometrically developed tension and maximum rate of tension rise (+dT/dtmax) in isolated left-ventricular papillary muscles perfused with Tyrode solution (32 degrees C, pH 7.4, bubbled with 95% O2.5% CO2, stimulation frequency: 0.2 Hz). Left-ventricular myosin isoenzymes were separated by pyrophosphate gel electrophoresis and the isoenzyme pattern was determined by densitometry. Isometrically developed tension (T) in hypertrophic myocardium remained unchanged, but +/-dT/dtmax decreased as compared with hearts of normal rats. Decreased +/-dT/dtmax recovered near to the level in normal rats by regression of cardiac hypertrophy. Left-ventricular myosin isoenzyme pattern shifted towards VM-3 in hypertrophied myocardium and shifted again toward VM-1 by regression of cardiac hypertrophy. In conclusion, myocardial contractility and ventricular myosin isoenzymes were changed in pressure-overloaded hypertrophy in rats and these changes were reversible to a normal level by regression of cardiac hypertrophy.
BACKGROUND: Almost all cases of superficial esophageal carcinoma are curable by endoscopic mucosal resection (EMR), but a precise diagnosis of the depth of tumor invasion is necessary to assess the indication for EMR. Although endoscopy has a high rate of accuracy for diagnosing the depth of tumor invasion, it depends on the experience of the examiner in interpreting surface information of the lesions. Today, endoscopic ultrasonography (EUS) is one of the most powerful techniques for obtaining objective tomographic images of a tumor. The high-frequency ultrasound probe is appropriate for EUS in cases of superficial esophageal carcinoma because of its excellent near-field resolution that provides precise ultrasound images under direct control of the endoscope. METHODS: We performed EUS with the Sonoprobe System in 85 cases of superficial esophageal carcinoma before treatment and evaluated the resected specimens histopathologically. We interpreted the depth of tumor invasion based on our fundamental studies of ultrasonograms taken with a 20-MHz probe. RESULTS: The clinical usefulness of the Sonoprobe with linear and radial scanning modes is due to its capacity to differentiate between mucosal and submucosal carcinoma by means of analyses of the muscularis mucosae. Although a clear assessment of microinvasion and lymphoid hyperplasia surrounding the tumor of interest remains speculative, the diagnostic accuracy rate for 96 lesions of superficial esophageal carcinoma reached 93% in terms of differentiating between mucosal from submucosal carcinoma. CONCLUSION: EUS with the Sonoprobe can play an important role in the pretreatment diagnosis of superficial esophageal carcinomas.
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