Itaru Kamata

Lymphangiogenesis in myocardial remodelling after infarction.

Aims:  The lymphatic system is involved in fluid homeostasis of the cardiac interstitium, but lymphangiogenesis in myocardial remodelling has not previously been examined histopathologically. The aim was to investigate by D2‐40 immunohistochemistry the sequential changes in lymphatic distribution in the process of myocardial remodelling after myocardial infarction (MI).

Significance of lymphatic invasion and cancer invasion-related proteins on lymph node metastasis in gastric cancer

Background and Aims:  Cancer invasion and metastasis are critical events for patient prognosis; however, the most important step in the whole process of lymph node (LN) metastasis in gastric cancer remains obscure. In this study, the significance of cancer cell behaviors, such as cell detachment, stromal invasion and lymphatic invasion on regional LN metastasis in gastric cancer was investigated by comprehensive immunohistochemistry.

Significance of Lymphatic Invasion and Proliferation on Regional Lymph Node Metastasis in Renal Cell Carcinoma

We studied the associations of lymphatic invasion and lymphatic vessel density around tumors with lymph node (LN) status in renal cell carcinoma (RCC) by immunohistochemical analysis using D2-40 antibody as a lymphatic marker. Surgically removed specimens from 76 cases with RCC, including 16 cases with LN metastasis, were used. Lymphatic vessel density around the tumor increased compared with normal kidneys but was not significant by LN status. Tumor size, tumor cell types, patterns of tumor growth, nuclear grade of tumor cells, venous invasion, lymphatic invasion, and primary tumor stage were predictive factors for LN metastasis. Based on multivariate regression analysis, only lymphatic invasion was an independent risk factor for LN metastasis. The immunohistochemical detection of lymphatics was useful for identifying the lymphatic invasion of RCC, and the presence of lymphatic invasion around RCC was an independent predictive factor for LN metastasis.

Severe Acute Pancreatitis with Complicating Colonic Fistula Successfully Closed Using the Over-the-Scope Clip System

A 44-year-old man presenting to our hospital emergency room with abdominal pain was hospitalized for hyperlipidemic acute pancreatitis. A pig-tail catheter was placed percutaneously to drain an abscess on day 22. Although the abscess improved gradually and good clinical progress was seen, pancreatic duct disruption was strongly suspected and endoscopic retrograde cholangiopancreatography was performed on day 90. An endoscopic nasopancreatic drainage tube was placed, but even with concurrent use of a somatostatin analogue, treatment was ineffective. Surgical treatment was elected, but was subsequently postponed as the abscess culture was positive for extended-spectrum β-lactamase-producing Escherichia coli and methicillin-resistant Staphylococcus aureus. Drainage tubography showed a small fistula of the colon at the splenic flexure on day 140. Colonoscopy was performed on day 148. After indigo carmine had been injected, a fistula into the splenic flexure of the colon showed blue staining. The over-the-scope clip (OTSC) system was used to seal the fistula and complete closure was shown. A liquid diet was started on day 159 and was smoothly upgraded to a full diet. Following removal of the pancreatic stent on day 180, drainage volume immediately decreased and the percutaneous drain was removed. On day 189, computed tomography showed no exacerbation of the abscess and the patient was discharged on day 194. This case of colonic fistula caused by severe acute pancreatitis was successfully treated using the OTSC system, avoiding the need for an open procedure.

Pathogenesis of lupus-like nephritis through autoimmune antibody produced by CD180-negative B lymphocytes in NZBWF1 mouse.

Toll-like receptors appear to play an important role in the pathogenesis of lupus-like nephritis in mice. In human and mouse, CD180 is a homologue of TLR4. In SLE patients, the number of CD180-negative B cells in peripheral blood changes in parallel with disease activity. In the present study using NZBWF1 mice, the population of splenic CD180-negative B cells increased with progression of renal lesions and aging. These cells produced both anti-dsDNA and histone antibodies; the peripheral blood levels of anti-dsDNA antibody increased markedly with aging. B cells infiltrating into renal lesions were CD180-negative and produced anti-dsDNA antibody. Considered together, these findings indicate that CD180-negative B cells contribute significantly to development of SLE-like morbidity in NZBWF1 mice by autoantibody production.

Endosonographic Preoperative Evaluation for Tumors of the Ampulla of Vater Using Endoscopic Ultrasonography and Intraductal Ultrasonography

Background/Aims In recent years, endoscopic snare papillectomy has been performed to treat tumors of the ampulla of Vater. This procedure requires accurate preoperative evaluation. In this study, we diagnosed the focal extension of such tumors by using endoscopic ultrasonography (EUS) and intraductal ultrasonography (IDUS), and examined the indications for endoscopic snare papillectomy. Methods The subjects were 48 patients with a papillary tumor (13 patients, surgical resection; 35 patients, endoscopic snare papillectomy) who were evaluated preoperatively with EUS and IDUS. The tumor-node-metastasis classification was used for the endosonographic evaluation and pathological diagnosis of these tumors. Results The diagnostic accuracy of EUS was 97% for diagnosing adenomas and pTis tumors, 73% for pT1 tumors, 50% for pT2 tumors, and 50% for pT3-4 tumors, for an overall accuracy of 85% for T-staging. The diagnostic accuracy of IDUS was 94% for adenomas and pTis tumors, 73% for pT1 tumors, 50% for pT2 tumors, and 100% for pT3-4 tumors, for an overall accuracy of 80% for T-staging. Conclusions EUS and IDUS are highly capable of evaluating tumors of the ampulla of Vater preoperatively. However, these techniques are not sufficient for evaluating the focal extension of carcinomas preoperatively. Currently, endoscopic snare papillectomy is adequate for treating adenomas and pTis tumors.

Hepatic artery pseudoaneurysm after endoscopic biliary stenting for bile duct cancer.

We report a case of a pseudoaneurysm of the right hepatic artery observed 9 mo after the endoscopic placement of a Wallstent, for bile duct stenosis, which was treated with transcatheter arterial embolization. The patient presented with obstructive jaundice and was diagnosed with inoperable common bile duct cancer. A plastic stent was inserted endoscopically to drain the bile, and chemotherapy was initiated. Abdominal pain and jaundice appeared approximately 6 mo after the beginning of chemotherapy. A diagnosis of stent occlusion and cholangitis was made, and the plastic stent was removed and substituted with a self-expandable metallic stent (SEMS) endoscopically. Nine months after SEMS insertion, contrast-enhanced computed tomography showed a pseudoaneurysm of the right hepatic artery protruding into the common bile duct lumen and in contact with the SEMS. The shape and size of the pseudoaneurysm and diameter of its neck was determined by contrast-enhanced ultrasonography using Sonazoid. A micro-catheter was led into the pseudoaneurysm in the right hepatic artery, GDC™ Detachable Coils were placed, and IDC™ Detachable Coils were then placed in the right hepatic artery on the distal and proximal sides of the pseudoaneurysm using the isolation method. There have been a few reports on pseudoaneurysm associated with stent placement in the biliary tract employing percutaneous transhepatic procedures, however, reports of pseudoaneurysms associated with endoscopic SEMS placement are very rare.

Right Hepatic Artery Pseudoaneurysm Complicating Acute Pancreatitis: A Case Report

Objective: To report a rare case of right hepatic artery pseudoaneurysm complicating acute pancreatitis based upon imaging findings obtained before and after the development of pseudoaneurysm. Clinical Presentation and Intervention: A 32-year-old male with a history of acute pancreatitis 1 year prior was readmitted for acute pancreatitis. Computed tomography (CT) and angiography after admission revealed pseudoaneurysm of the right hepatic artery. Transcatheter arterial embolization with coils was used to successfully treat the pseudoaneurysm. A CT and angiography 1 year earlier did not reveal any pseudoaneurysm. Conclusion: This patient with a rare right hepatic artery pseudoaneurysm complicating acute pancreatitis was successfully treated with coil embolization.

Duct of Luschka diagnosed by sonography in a patient with bile duct carcinoma and intrahepatic bile duct dilatation

The bile duct of Luschka (BDL) is an anatomic anomaly that is an important cause of bile leakage after bile duct surgery. We report a case of bile duct carcinoma with dilated BDL that was diagnosed by ultrasonography (US). An 83‐year‐old man presented with an obstructive jaundice. US on admission revealed the presence of a solid hypoechoic mass in the bile duct at the hepatic duct confluence and a branch of the bile duct, about 2–4 mm in diameter, distinct from the dilated right anterior hepatic duct slightly upstream of the tumor. This branch had a spiral structure, extended along the gallbladder bed on the surface of segment 5 (S5) of the liver, and emanated small branches that entered the hepatic parenchyma. There has been no previous report of delineation of BDL by preoperative US.