Toshihiko Kurohiji

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.

Schwannoma of the liver: Report of two surgical cases

Two surgical cases of benign schwannoma of the liver were examined: A 64‐year‐old female who was admitted to hospital for the treatment of early gastric cancer (case 1) and a 69‐year‐old female who had pitting edema In the legs (case 2). Diagnostic imaging revealed large solid masses located In the caudate lobe through to the left lobe of the liver in case 1 and in the left lobe in case 2. Both patients showed no signs of von Recklinghausens disease. Partial hepatectomies were performed and the maximum diameter of their resected hepatic tumors was 4 cm and 15 cm, respectively. Histologically, the well‐demarcated tumors were yellowish In color, elastic‐hard In consistency and consisted predominantly of short spindle‐shaped cells proliferatlng In an interlacing fashion. The tumor lesions were separated by fibrous bands and surrounded by a lymphoid cuff. Immunohistochemically, the tumor cells were positive for S‐100 protein. The tumors were diagnosed as benign hepatic schwannoma.

Detection of hepatitis-C virus and hepatitis-C virus replication in hepatocellular carcinoma by in situ hybridization

BACKGROUND Although hepatitis C virus (HCV) is a major causative agent of hepatocellular carcinoma (HCC), the role of this virus in carcinogenesis is not fully understood. METHODS We studied HCV infection and replication by detecting plus- and minus-strand HCV RNA by in situ hybridization (ISH) in surgically resected HCCs and adjacent non-cancerous tissue obtained from 15 anti-HCV antibody-positive patients with HCC. RESULTS Plus-strand HCV RNA was found in 9 of 15 HCCs. Both plus- and minus-strand HCV RNA were detected in four of these nine patients. In non-cancerous tissues obtained adjacent to the HCC, plus-strand HCV RNA was found in 10 of 15 patients, whereas both plus- and minus-strand HCV RNA were detected in 7 of these 10 patients. The degree of staining by ISH did not correlate with the differentiation of the HCC, histologic classification of the non-cancerous tissue, serum HCV RNA levels, or serum transaminase levels. CONCLUSIONS HCV can be found in and replicates in both hepatoma cells and in non-cancerous hepatocytes in anti-HCV antibody-positive patients with HCC. The direct effects of HCV viral gene products on normal hepatocytes in the development of HCC require additional study.

Lack of detection of hepatitis C virus replicative intermediate in abdominal lymph nodes

Abstract Deep abdominal lymph node enlargement has been detected by ultrasound examination in patients with hepatitis C virus (HCV) infection. To clarify the potential for extrahepatic existence and/or replication of HCV in such abdominal lymph node, positive- and negative-strand HCV RNA were investigated in abdominal lymph node mononuclear cells (MNC) as well as in the serum of patients with HCV. The study population consisted of eight hepatocellular carcinoma (HCC) patients positive for antibody to HCV (anti-HCV). Lymph nodes of hepatoduodenal ligament were resected at surgery for HCC. Both HCV RNA strands were examined using highly strand-specific r Tth reverse transcription-polymerase chain reaction (r Tth RT-PCR) followed by Southern blotting analysis. Positive-strand HCV RNA was detected in three (37.5%) abdominal lymph node MNC and in seven (87.5%) serum samples. Negative-strand HCV RNA was not detected in abdominal lymph node MNC, while it was observed in two (25%) serum samples. Histologically, the lymph nodes taken from subjects showed reactive follicular hyperplasia with or without the presence of HCV RNA. These observations suggest that HCV is located in the abdominal lymph nodes, but does not replicate within them. Negative-strand HCV RNA detected in serum samples may have been due to contamination with circulating HCV RNA from hepatocytes.

Effect of perfusion and blood content on ultrasonic backscattering of liver tissue

The purpose of this study was to determine the effect of blood flow perfusion and red cell content on ultrasonic scattering by liver tissue. Data acquisition for ultrasonic tissue characterization (UTC) employing analysis of the backscattered echoes from the power spectrum was obtained from the same region of pig liver tissue under four conditions: 1) normal perfusion in situ, 2) ischemia in situ in the living pig, 3) ischemia in situ immediately postmortem, and 4) immediately after excision of the liver. Discriminant function analysis was used to evaluate differences in the two basic parameters from the normalized power spectrum: slope and intercept. Normal perfused liver had significantly higher intercept values and lower slope values than liver under the other three conditions. Excised liver showed the lowest intercept and highest slope values (p < 0.01). These experiments indicate that differences in perfusion produce significant differences in ultrasonic scattering by liver tissue (ischemia caused a 3 dB drop in intercept amplitude). Normal or ischemic in vivo and in vitro liver tissue is associated with different patterns of ultrasonic scattering, and scattering data under these various circumstances are not equivalent.

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.

Operative ultrasonography in the diagnosis of cardio-vascular invasion of lung cancer.

術前心血管系への浸潤程度が充分把握できなかった原発性肺癌9例に対し, 術中超音波検査を施行した. 術中超音波検査は, 開胸又は胸骨縦切開直後に, 組織剥離に先立って行われた. 本法を行った9例中8例は超音波所見と手術所見の一致がみられ, 病理組織学的に確証が得られた. 本法は有用な術中診断法であり, 今後積極的に拡大手術を行ってゆく上で, 有効な手段となり得るものと考えられた.

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.