Yuichi Yamashita

Evaluation of endorectal ultrasound for the assessment of wall invasion of rectal cancer. Report of a case.

To accurately assess the depth of cancer invasion, endorectal ultrasound was performed using a radial scanner (Aloka, 7.5 MHz) in 145 patients with rectal cancer. High-resolution ultrasound clearly depicted five- or seven-layer echographic structures in the normal rectal wall, and demonstrated cancer as a hypoechoic lesion. These layer structures provided an important feature in determining the depth of cancer invasion. Rectal cancers of 122 patients were examined thoroughly by endorectal ultrasound. In 95 of these patients (77.9 percent), ultrasonic assessment of the depth of cancer invasion as classified in four groups was correct, corresponding accurately to the microscopic findings. Ultrasonography overestimated the depth of cancer invasion in 21 patients, however, and underestimated it in six patients. This study indicated that a cause of the overestimation was inflammatory cell infiltration around cancer, and that one possible cause of underestimation was microscopically minimal invasion of cancer. Although there are certain limitations of endorectal ultrasound, this ultrasound technique will provide valuable information to determine the preoperative staging of rectal cancer.

Detection of unrecognized liver metastases from colorectal cancers by routine use of operative ultrasonography

The importance of diagnosis and detection of liver metastases cannot be overemphasized for the treatment and prognosis of colorectal cancers. As a new diagnostic technique, operative ultrasonography has been performed during 33 operations for colorectal cancers including three operations for metachronous liver metastases. Of these, in five patients (15.2 percent) ultrasonography using 5- or 7.5-MHz instruments identified metastatic tumors that had not been diagnosed during preoperative imaging studies or at exploration. Most of these tumors were approximately 1 cm in size and nonpalpable. Cases of these five patients are presented in this report. High-resolution operative ultrasonography is considered to be a valuable method for detection of unrecognized metastatic tumors and for precise localization and spatial assessment of these hepatic lesions. Because it is safe, simple, and highly sensitive, the routine use of operative ultrasound is encouraged during surgery upon colorectal cancers for systematic screening of metastatic liver tumors.

A case of cystic lymphangioma of the pancreas

We report a case of a 58-year-old man presenting with a mild attack of upper abdominal pain and who was found to have a swollen pancreatic body and tail. Pathological study of the resected mass revealed cystic lymphangioma. Only 30 cases of lymphangioma of the pancreas, including our case, have been reported to date. Here we present this case in detail and discuss the differential diagnosis of cystic lesions in the pancreas.

Evaluation of hepatectomy for hepatic metastasis of colorectal cancer.

大腸癌肝転移に対する肝切除の評価を臨床病理学的立場から検討し, 以下の結果を得た.(1) 肝切除例では化学療法例に比べ長期生存例が存在した.(2) 肝切除例における肝切除後の生存期間は, リンパ節転移や組織所見 (分化度, リンパ管侵襲) などの原発巣側の因子によって有意差が認められた.(3) 肝切除の術式, 肝転移の時期, 程度, 個数などの転移巣側の因子については, 生存期間に有意差は認められなかった.(4) 肝切除後の再発は残肝, 肺が高頻度であった.以上のことより (1) 肝切除は化学療法よりも有効性があるが, 原発巣の組織学的特徴を考慮した合理的肝切除を施行すべきである.(2) 肝切除後の再発をいかに予防するかが今後の課題であると考えている.

Direct observation of the portal vein interior by intra‐operative angioscopy in the dog and man

The purpose of this study was to develop the technique of intra‐operative portal angioscopy using a portal angioscope, and to demonstrate its potential use in the therapy for patients with hepatocellular carcinoma (HCC) bearing a portal thrombus. Portal angioscopes, Olympus BF3C10 and CHFP10 of a diameter of 3.5 mm and 4.8 mm, respectively, were used during operation in five dogs, two patients with hepatic metastasis from colon cancer and three patients with HCC having a portal tumour thrombus. The portal vein and hepatic artery were ligated simultaneously, and the angioscope was immediately introduced under direct vision through a small portal venotomy. Blood in the portal vein was almost fully diverted by infusion of heparinized saline through a channel of the angioscope at a rate of 3 mL/min in dogs and 5 mL/min in patients with hepatic metastasis. Rates of 6 mL/min and 10 mL/min in dogs and patients, respectively, were adequate to clear completely the portal vein of blood. In patients with HCC, portal tumour thrombectomy was performed with a Fogarty balloon catheter by suctioning thrombi through a channel of the fibrescope after visual study of the portal thrombus.

Screening of liver metastasis from colorectal cancer by operative ultrasonography.

大腸癌肝転移の検出能向上のために, 新しいスクリーニング検査法として高周波装置を用いた術中超音波検査を100例の大腸癌手術時に施行した. その結果, 従来の検査法では見落されていた16個の深在小肝転移巣 (4～16mm大) を12例に検出できた. 肝転移巣検出に対する術中超音波検査のspecificity (特異度) 94.9%は他検査と同等に高値であり, 一方, 術中超音波検査のsensitivity (敏感度) 96.3%は術前超音波37.0%, CT42.6%, 術中視診触診59.6%に比べ有意に優れていた. 術中超音波検査は従来の方法より高い精度を有する上, 安全かつ短時間に実施できることから, 肝転移巣スクリーニングのために, 大腸癌術中にルーチンに応用することを推奨したい.