Masami Kawai

Mechanical stress-dependent secretion of interleukin 6 by endothelial cells after portal vein embolization: clinical and experimental studies

BACKGROUND/AIMS Interleukin-6 (IL-6) is an essential early signal in liver regeneration, however, little is known about what triggers IL-6 release. Changes in portal hemodynamics after portal vein embolization (PVE) may contribute to IL-6 release, leading to regeneration of non-embolized lobe. METHODS In 22 patients who underwent right PVE, the diameters of the left portal branches, liver volumes, and serum concentrations of IL-6, tumor necrosis factor-alpha (TNF-alpha), and hepatocyte growth factor (HGF) were measured. We then studied endothelial cells cultured on an elastic silicone membrane and subjected to continuous uni-axial stretch. Supernatant cytokine concentrations were measured. RESULTS The diameters of the portal branches increased by 150% after PVE. Serum IL-6 concentrations increased within 3h after PVE. The concentrations of TNF-alpha and HGF remained unchanged. The left lobe volume increased 2 weeks after PVE. The IL-6 concentrations in the supernatant of endothelial cells with stretch stress were higher than that in the non-stretched control group. CONCLUSIONS These findings indicate that PVE dilates the portal branches in the non-embolized lobe, exposing hepatic vasculature to stretch stress. This hemodynamic change may act as a trigger for IL-6 release from endothelial cells and contribute to the activation of regenerative cascade in the non-embolized lobes.

Adenosquamous carcinoma of the gallbladder with tumor thrombus in left portal trunk

We report a surgically resected case of adenosquamous carcinoma of the gallbladder accompanied by portal tumor thrombosis, which is regarded as a rare complication. A 73-year-old man was admitted to our hospital because of epigastralgia. Preoperative examinations led to a diagnosis of advanced gallbladder carcinoma with liver metastasis, and operation was performed. Since intraoperative ultrasonography showed a tumor thrombus in the left main portal trunk originating from the metastatic lesion in the left medial segment of the liver, extended left lobectomy with extrahepatic bile duct resection and lymph node dissection was performed, instead of right trisegmentectomy, as proposed preoperatively. Histological examination revealed adenosquamous carcinoma of the gallbladder with medullary growth that was similar to the hepatocellular carcinoma, most notably in the metastatic lesion of the liver and in the portal tumor thrombus. We discuss the relation between portal tumor thrombosis and medullary tumors, and note the atypical operative method employed.

A Case of the Primary Small Intestinal Carcinoma with its Metastasis to the Stomach Accompanied by the Primary Mucinous Carcinoma of the Colon.

症例は68歳の男性で下血で発症し, 血色素4.5g/dLと著明な貧血を認めた. 胃内視鏡および小腸造影検査により胃癌と小腸腫瘍の重複癌と診断し手術した. 空腸に15cm径の腫瘤を認め, 第1, 2空腸動脈を切離してこれを摘出し, さらに幽門側胃切除を施行した. また結腸肝轡曲に結腸粘液癌を認めたため, 右半結腸切除を追加した. 組織学的には小腸病変は印環細胞を伴わない粘液癌であったが結腸の粘液癌には印環細胞が多数認められた. 胃の病変は粘膜下層に病変の主座があり, 小腸病変に類似した粘液癌の中央に正常胃粘膜上皮の配列を認めた. 以上より本例を小腸・結腸の重複癌および小腸癌の胃転移と診断した. 術後は良好に経過し, 術後1年5か月を経た現在は外来通院中で再発の徴候を認めない. 小腸癌はまれで予後不良であり, 小腸癌を原発とする胃転移癌の本邦での報告は認められなかった.