Hideo Atari

Low-dose particulate polyvinylalcohol embolization in massive small artery intestinal hemorrhage. Experimental and clinical results.

The branches of the superior mesenteric artery were embolized with polyvinylalcohol (PVA) particles 149 to 250 mu (small), 420 to 590 mu (medium), and 590 to 1000 mu (large), respectively, in three groups of dogs. In the small PVA particle group, all three dogs died. In the medium and the large PVA particle groups, nine of the 11 dogs showed no significant ischemic change and the remaining two (one dog in the medium PVA group and one in the large PVA group) had a superficial ulcer. This study suggests that PVA embolization can be performed safely if particles of 420 mu or larger are used. In clinical studies, large PVA particles were used in embolization therapy for massive intestinal hemorrhage from small arteries in five patients. All had the hemorrhage from ulcer disease in the small bowel (four patients) and the ascending colon (one patient). Three patients were completely controlled with no recurrence of hemorrhage. The remaining two experienced rebleeding after embolization. No major complication was found in this series. It is concluded that low-dose large PVA particles are suitable as an embolic material for transcatheter occlusion of small-artery intestinal hemorrhage.

Study on Small Colorectal Polyps and Early Cancers

Abstract: We investigated the histopathological features of polyps with a diameter of less than 5 mm that had been resected by a snare or hot‐biopsy (1, 357 lesions in 712 patients), and considered the problems associated with these techniques. 67.7% of the polyps were adenomas, 15.5% were metaplastic polyps, 0.6% were colon cancers, and 0.1% were carcinoids. Eighty percent of the polyps situated on the oral side of the descending colon were adenomas. Although adenomas occurred somewhat more frequently in the sigmoid colon, they tended to be distributed evenly throughout the entire colon. The reddened color of the surface of the polyps tended to accompany adenomas, while a whitish surface color was frequently associated with metaplastic polyps. Multiple polyps occurred in 57% of the patients and 33.7% of the patients had a large polyp with a diameter of more than 6 mm. In six out of eight cases of cancer the cancers were limited to the mucosa (m), the other 2 were submucosal invaded carcinomas. One of these cases was a depressd type of cancer and the other lesions were classified as being elevated type polyps. The elevated type of diminutive early colorectal carcinoma with a diameter of less than 5 mm was difficult to distinguish endoscopically from benign polyps, so we recommended that small colonic polyps should be removed when encountered during a colonoscopy.

Clinical and Endoscopic Study of Ischemic Colitis

The clinical signs and symptoms of ischemic colitis have been analyzed. Eighty‐one cases were investigated; there were 62 cases of the transient type, 15 of the stricturing type, and 4 cases of the gangrenous type. All cases were diagnosed by colonoscopy.

An immunohistopathological study on peptide hormone-laden tumor cells in biliary cystadenocarcinoma.

嚢胞性腺癌の3症例を検索し腫瘍組織内の腫瘍細胞にGrimelius染色及びFontana-Masson染色を施行し二つの何れの染色にも陽性を呈する腫瘍細胞の散在性の出現をみとめた.これらの染色に陽性の腫瘍細胞は内分泌細胞のマーカーであるクロモグラニンに対しても陽性で,更にセロトニン,カルチトニン並びにガストリンに対しても陽性であることが確認された.しかし,pancreatic peptaide,ソマトスタチン,NSE, S-100の各種マーカーに対しては陰性であった.このように嚢胞性腺癌にはペプタイドホルモンを保有する腫瘍細胞が散在性に出現することが明らかとなった.