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T Namieno

Publications and source records attributed to T Namieno.

At least 19 recordsLinked to original sources
PubMed2001

Survival-associated histologic spreading modes of operable intrahepatic, peripheral-type cholangiocarcinomas.

We investigated survival-associated histologic and metastatic spreading modes of intrahepatic, peripheral-type cholangiocarcinomas resected to contribute to surgical control of the tumor. Previous results have been mostly obtained from autopsies, reflecting the terminal status of patients. We clinicopathologically reviewed the resected 20 intrahepatic, peripheral-type cholangiocarcinomas and investigated the histologic findings of resected specimens and medical records to assess spreading modes along with patients' survival. The carcinoma cells superficially spread in the ductal epithelium in 75%, infiltrated along Glisson's system and migrated multidirectionally in 100%, and permeated the vascular network in 80%. The cumulative survival rate significantly related to vascular permeation, extrahepatic metastases, and lymphatic, neural, and nodal involvement but not to ductal spread, tumor size (cutoff size 5 cm), or intrahepatic metastases by the log-rank test. The patients with lymphatic, neural, or nodal involvement died early after surgery. Practically, only vascular permeation was identified as a significant independent variable for survival using multivariate analysis. Peripheral cholangiocarcinomas spread mainly in three modes: ductal spread, infiltration along Glisson's system, and vascular permeation. In the practically operable cases, vascular permeation is closely related to survival, and intrahepatic metastasis may be surgically controlled to some degree.

Aged↗
PubMed2001

Pancreas: imaging diagnosis with color/power Doppler ultrasonography, endoscopic ultrasonography, and intraductal ultrasonography.

Recent advances of ultrasound imaging have made possible to depict various diseases and conditions of the pancreas. Color/power Doppler ultrasonography, endoscopic ultrasonography, and intraductal ultrasonography are feasible to show vascular abnormalities, differentiate the solid and cystic tumors, decide tumor extent, and help to perform interventional treatments of the pancreatic diseases. Those techniques will contribute to the more precise and easier diagnosis and to prompt decision of the treatments of the pancreatic disorders. Radiologists should recognize the diagnostic feasibility and limitations of those techniques in order to avoid unnecessary examinations on the patients, and obtain precise diagnostic images.

Endoscopy, Gastrointestinal↗
PubMed2001

Virtual CT cholangioscopy: comparison with fiberoptic cholangioscopy.

BACKGROUND AND STUDY AIMS: No studies comparing virtual computed tomography (CT) cholangioscopy of the common bile duct compared with fiberoptic cholangioscopy are available. The aim of our study was to evaluate the feasibility of virtual CT cholangioscopy of the common bile duct. PATIENTS AND METHODS: The study population comprised 52 patients (25 women, 27 men; mean age 56.5, range 32 - 81) with biliopancreatic disorders. Endoscopic images were produced by a volume-rendering method and a perspective projection. The ability to detect the endoluminal view and abnormalities of the common bile duct by virtual CT cholangioscopy and fiberoptic cholangioscopy was evaluated. RESULTS: Except for two cases (4 %), virtual CT cholangioscopy revealed excellent and moderate endoluminal visualization. There was no significant difference between the techniques (virtual CT cholangioscopy vs. fiberoptic cholangioscopy: excellent, 73 % vs. 85 %, P = 0.149; moderate 23 % vs. 15 % (P = 0.319); poor, 4 % vs. 0 %, P = 0.153). Virtual CT cholangioscopy revealed no significantly different ability to detect stenosis and obstruction of the common bile duct, compared with fiberoptic cholangioscopy. However, the ability of virtual CT cholangioscopy to detect minute papillary tumors (virtual CT cholangioscopy 30 % vs. fiberoptic cholangioscopy 100 %, P = 0.001) and stones smaller than 5 mm (virtual CT cholangioscopy 25 % vs. fiberoptic cholangioscopy 100 %; P = 0.002 was significantly less than that of fiberoptic cholangioscopy. CONCLUSIONS: Virtual CT cholangioscopy cannot replace fiberoptic cholangioscopy completely. However, the use of this technique, instead of fiberoptic cholangioscopy, may be feasible for following up patients after biliary intervention.

Adult↗
PubMed2001

Congenital arteriovenous malformation of the pancreas: its diagnostic features on images.

To analyze diagnostic features on images of congenital arteriovenous malformation (AVM) of the pancreas, we analyzed the diagnostic findings in six patients with the disease, using gray-scale ultrasonography (US), color Doppler US, computed tomography, and angiography and analyzed previously reported cases. AVM characteristic findings on images were multiple, small hypoechoic nodules on US, mosaic appearance of the lesion and pulsatile wave form in the portal vein on color Doppler US, conglomerated small nodular enhancement of the lesion and early appearance of the portal vein on CT, and a racemose network and early appearance of the portal vein on angiography. Five of the six patients underwent surgery, and all resected specimens were histologically found to be AVMs of the pancreas; however, one with developed portal hypertension at surgery died of repeated bleeding from esophageal varices. From analysis of total of 35 cases including our six cases, a mosaic appearance of the lesion was found in 100% and a pulsatile wave form in the portal vein in 77.8% on color Doppler US. Color Doppler US is noninvasive and useful for detecting congenital AVM of the pancreas at an early stage, preventing the portal hypertension causing esophageal varices and their rupture.

Adult↗
PubMed2000

Power Doppler sonography: evaluation of hepatocellular carcinoma after treatment with transarterial embolization or percutaneous ethanol injection therapy.

OBJECTIVE: The aim of this study was to compare tumor detectability by assessing the vascularity on power and color Doppler sonography and CT after transarterial embolization or percutaneous ethanol injection therapy or both in hepatocellular carcinoma. SUBJECTS AND METHODS: Forty-seven nodules of hepatocellular carcinoma (size, 28 +/- 7 mm [mean +/- standard deviation]; range, 20-40 mm) in 38 patients were treated with transarterial embolization (n = 6), percutaneous ethanol injection therapy (n = 23), and transarterial embolization plus percutaneous ethanol injection therapy (n = 9). Power Doppler sonography, color Doppler sonography, and CT were performed before and 2 weeks, 3 months, and 6 months after the treatments. The existence of hepatocellular carcinoma was confirmed by positive findings for color signals on both Doppler sonography techniques and for tumor stains on CT. All the tumors were determined to be malignant by microscopic examination of biopsy specimens. RESULTS: Before the treatments, power Doppler sonography (100%) and CT (100%) were significantly more effective than color Doppler sonography (61.7%) (p < 0.001, for both). Six months after the treatments, the sensitivity of power Doppler sonography (87.5%) was significantly better than that of color Doppler sonography (12.5%) but was not significant in comparison with CT (66.6%). However, power Doppler sonography detected color signals in two of three tumors in which iodized oil was accumulated and no tumor stain appeared on CT, and the two lesions detected with power Doppler sonography were carcinomas. CONCLUSION: Power Doppler sonography can be considered the most sensitive technique in assessing the viability of hepatocellular carcinoma treated with transarterial embolization or percutaneous ethanol injection therapy or both.

Adult↗
PubMed1998

Assessing the suitability of gastric carcinoma for limited resection: endoscopic prediction of lymph node metastases.

Some early gastric carcinomas are free of lymph node involvement; however, the pathosis of these carcinomas is neither well understood nor reflected in the choice of less extensive treatment. We investigated the relation of nodal involvement to pathologic findings of the resected specimens. We present promising standards for predicting the nodal status of early gastric carcinomas, contributing to the indication for limited surgery. The relation of lymph node metastasis to tumor size, infiltration depth, macroscopic appearance, and histologic type of early gastric carcinomas were investigated in 1470 patients with a single primary early gastric carcinoma. Of these carcinomas, 763 were limited to the mucosa (mucosal carcinoma) and 707 to the submucosa (submucosal carcinoma). The overall incidence of lymph node metastasis was 9.0%: 2.1% in mucosal carcinomas and 16.5% in submucosal ones, with a significant (p < 0.001) difference of nodal involvement between the two. The macroscopically elevated or compound-type carcinomas 10 mm or less in diameter were all node-negative, whereas some depressed-type carcinomas were node-positive. The incidence of undifferentiated carcinomas increased with tumor diameter, irrespective of whether they were mucosal or submucosal carcinomas, and they were significantly more node-positive than were differentiated carcinomas: p < 0.001 for mucosal carcinomas and p < 0.05 for submucosal ones. The carcinomas satisfying the following criteria are node-negative and eligible for limited surgery: (1) mucosal carcinoma; (2) elevated lesion < 10 mm in diameter; (3) differentiated adenocarcinoma; and (4) no ulcer or ulcer scar. The other carcinomas are potentially node-positive and standard surgery is recommended.

Adenocarcinoma↗
PubMed1998

Assessing the suitability of gastric carcinoma for limited resection: histologic differentiation of endoscopic biopsy.

Histologically differentiated adenocarcinoma satisfies one of the criteria for limited surgery for mucosal carcinoma of the stomach: however, the histology of the endoscopic biopsy specimen is often different from that of the resected specimen. The medical records of 1018 early gastric carcinomas were retrospectively analyzed to investigate the relation between the histologies of biopsy and resected specimens. Regression analysis showed that the histologies of biopsy specimens were significantly related to those of resected specimens (r = 0.677, n = 5, p = 0.0288) for the mucosal carcinomas, but their relation was not significant for the submucosal carcinomas (r = 0.677, n = 5, p = 0.2091). By analyzing the 344 differentiated mucosal carcinomas, moderately differentiated tubular adenocarcinomas were seen to be frequently less differentiated at resection. The histology of the biopsy specimens from mucosal carcinoma of the stomach grossly satisfies one of the criteria for limited surgery, but moderately differentiated adenocarcinoma may not be suitable for this treatment.

Adenocarcinoma↗
PubMed1998

Tumor recurrence following resection for early gastric carcinoma and its implications for a policy of limited resection.

Some patients suffer postoperative recurrence after curative resection of early gastric carcinoma. This study reviewed consecutive patients with a single primary lesion and analyzed the relation between the pathologic findings and recurrence of early gastric carcinomas for determining indications for limited surgery. Among the 1585 consecutive patients with a solitary primary lesion of an early gastric carcinoma who had undergone curative surgery between 1963 and 1989 at one general hospital, pathologic findings relating to recurrence were analyzed according to Japan's General Rules for Gastric Cancer Study in Surgery and Pathology. Of these carcinomas, mucosal carcinomas comprised 701 (44.2%) and submucosal ones 884 (55.8%). The total recurrence rate in this series was 1.0%. Submucosal carcinomas (1.6%) were significantly (p < 0.02) more recurrent than mucosal ones (0.29%). Of the 16 patients with recurrence, 10 (62.5%) died within 5 years after surgery, frequently because of blood-borne metastasis. Macroscopically elevated components, the degree of histologic differentiation, and lymph node metastasis significantly contributed to the postoperative recurrence. After detailed analysis of submucosal carcinomas, it is strongly suspected that carcinomas with a macroscopically elevated component were significantly associated with nodal involvement and microvessel invasion, and that these abnormalities lead to recurrence. Among the early gastric carcinomas, differentiated submucosal carcinomas with a macroscopically elevated component, lymph node metastasis, or both have the most potential of recurrence after surgery. Mucosal carcinomas must be restricted to limited surgery, but, blood-borne metastasis should be carefully avoided.

Adenocarcinoma, Mucinous↗
PubMed1998

Transverse colonic stenosis.

A 3-year child presented with episodic lower abdominal pain; during the eighth attack, a mass was palpable in the left upper quadrant, and a barium enema revealed a stenotic area in the transverse colon. This was resected and an uneventful postoperative course followed. Subsequently, the child has remained symptom-free. instruments are no longer in use.

Colon↗
PubMed1998

Mucin-producing pancreatic tumors: comparison of MR cholangiopancreatography with endoscopic retrograde cholangiopancreatography.

PURPOSE: To compare magnetic resonance cholangiopancreatography (MRCP) with endoscopic retrograde cholangiopancreatography (ERCP) in the detection of mucin-producing pancreatic tumors. MATERIALS AND METHODS: The authors retrospectively reviewed MRCP and ERCP images obtained in 28 patients with mucin-producing pancreatic tumors. Detectability of the pancreatic duct and its branches, intraductal cystic lesions, and intracystic nodules or septa was assessed. RESULTS: MRCP depicted cystic dilated ductal branches significantly better than did ERCP (P < .001). The difference in the number of nodules or septa detected with MRCP compared with ERCP was not significant. MRCP, however, simultaneously showed not only the main pancreatic duct but also the cystic lesions; this was not always possible with ERCP. CONCLUSION: MRCP appears to be more effective and less invasive than ERCP to evaluate changes in the size and extent of tumors and to determine if new lesions appear, as well as to follow up mucin-producing pancreatic tumors.

Adenocarcinoma, Papillary↗
PubMed1998

Differential diagnosis of small hepatocellular carcinoma and adenomatous hyperplasia with power Doppler sonography.

OBJECTIVE: The aim of this study was to compare the ability of power Doppler sonography and color Doppler sonography to differentiate hepatocellular carcinoma (HCC) from adenomatous hyperplasia (AH). SUBJECTS AND METHODS: In 48 patients with cirrhosis of the liver, color Doppler sonography and power Doppler sonography were performed on 53 hepatic nodules smaller than 20 mm in diameter (32 nodules were HCC; 21 nodules were AH). We evaluated the detectability of the pulsatile and continuous flows in the nodules at each hepatic segment. RESULTS: Thirty-four percent of nodules produced color signal on color Doppler sonography; 77%, on power Doppler sonography (p < .01). The identification rate of nodules in the left lateral segment was significantly lower than in other segments. Continuous flow was seen in the nodules of both HCC and AH. However, only in HCC did we see pulsatile flow. For HCC, pulsatile flow was seen with color Doppler sonography in 25% of the nodules smaller than 10 mm in diameter and in 50% of the nodules between 10 and 20 mm. With power Doppler sonography, pulsatile flow was seen in 67% (p < .05) of the nodules smaller than 10 mm and in 90% (p < .01) of the nodules between 10 and 20 mm. Sensitivity and negative predictive value in the differentiation of HCC from AH were significantly higher with power Doppler sonography than with color Doppler sonography (81% versus 41%, respectively, for sensitivity and 78% versus 53%, respectively, for negative predictive value). Specificity, positive predictive value, and efficacy of both color Doppler sonography and power Doppler sonography were 100%, 100%, 60%, respectively. CONCLUSION: On the basis of our results, power Doppler sonography is more sensitive than color Doppler sonography in revealing small HCC and in differentiating HCC from AH under physiologic hemodynamic conditions.

Aged↗
PubMed1997

Establishment of a primary culture of Echinococcus multilocularis germinal cells.

This study was designed to establish an in vitro primary culture of germinal cells of Echinococcus multilocularis, a parasite that causes alveolar echinococcosis of the liver (AEL). We also investigated the temperature-dependency of the cultured cells. The germinal cells, which originated from a human lesion, were cultured by an original fluid-suspension method at 25 degrees C or 37 degrees C for 4 weeks. Anchorage-dependent and -independent cells were observed by light microscopy, transmission electron microscopy, and immunocytochemistry to confirm their origin. Cell number and viability were examined by immunocytochemistry and mitochondrial exclusion test. The cultured cells were also inoculated into jirds (Meriones unguiculatus) to evaluate metacestode formation. Morphology and immunocytochemistry showed that the cultured cells were typically germinal cells. The cell number declined gradually over the 4-week culture period, but viability remained at 50% at 3 weeks. These findings were not associated with either of the two culture temperatures; moreover, host-associated cells were not noted in the cultured cells at 25 degrees C. The implanted cells formed metacestodes in the jird peritoneal cavity, and their histology demonstrated mature and typical alveolar-type echinococcal cysts. We successfully established an in vitro primary culture of germinal cells. This should contribute to future studies, and, hence, a better outcome for patients with AEL.

Animals↗
PubMed1997

Contribution of mass screening system to resectability of hepatic lesions involving Echinococcus multilocularis.

The prognosis for patients with alveolar echinococcosis of the liver (AEL) is excellent when the lesion is completely resected. Early detection of the disease and subsequent resection of the lesion are thus indispensable; however, the usefulness of screening systems is now controversial. This study was designed to compare screened and non-screened patients according to stage classification and to re-evaluate the effect of screening. We studied a total of 82 patients (63 screened and 19 non-screened). The stage classification showed a significant intergroup difference (P < 0.002). The largest tumors ranged from 30 to 100 mm, and there was a significant intergroup difference (P < 0.0014). Ultrasonography showed even small lesions in the screened patients. The complete resection rate was 74.6% for the screened patients, and 21.1% for the non-screened patients, showing a significant difference (P < 0.0001). The rate of unresectable lesions was higher in the non-screened patients (32%) than in the screened patients (11%), showing a significant difference (P < 0.04). The present screening system contributes to early detection and subsequent resection of AEL, leading to a better outcome.

Animals↗
PubMed1997

Intraperitoneal dissemination probably caused by needle biopsy of alveolar echinococcosis of the liver: experimental study.

Alveolar echinococcosis of the liver (AEL) is a parasitosis with a potential for malignant tumor-like behavior. The disease is diagnosed by a combination of serologic tests, diagnostic images, and the histology of needle biopsy specimens. It remains unresolved whether the biopsy induces subsequent troubles. We designed this study to investigate critical problems after needle biopsy of AEL lesions using an experimental model. Five samples were prepared from the resected lesions of AEL patients: (A) 10% suspension of trypsin digests of the minced lesion; (B) 10% suspension of mesh-filtered sediment of the minced lesion; (C) 10% sediment suspension after washing the nonminced lesion; (D) supernatant after centrifuging intracystic fluid; (E) 10% sediment suspension after centrifuging intracystic fluid. A 1-ml aliquot of each sample was injected intraperitoneally into jirds (gerbils) or cotton rats, respectively. The animals were sacrificed 12 weeks later, and intraperitoneal metacestodes were observed. All samples except D developed metacestodes, and their histologies were all lesions of typical alveolar echinococcosis. These results suggest that a needle biopsy may cause intraperitoneal dissemination or tracial implantation of the parasites along the track of the needle.

Animals↗
PubMed1997

Solitary cystic tumor of the pancreas: EUS-pathologic correlation.

BACKGROUND: It is clinically important to distinguish neoplastic from non-neoplastic pancreatic cysts. METHODS: Retrospective correlations were made between pathologic and EUS data from 52 pancreatic solitary cystic tumors: mucinous cystadenoma (10), mucinous cystadenocarcinoma (7), serous cystadenoma (5), ductectatic mucinous cystic tumor (10), solid and papillary epithelial neoplasm (5), and non-neoplastic cyst (15). The mean tumor size was 3.5 cm (range, 1.2 cm to 6.0 cm). RESULTS: Six classifications of the internal structures of these cysts were developed: thick wall type, tumor protruding type, thick septal type, microcystic type, thin septal type, and simple type. Although all neoplastic cysts belonged to the first four types, all non-neoplastic cysts belonged to the last two types. The accuracy of EUS for differentiating tumors was estimated at 96% and 92%, respectively, by two observers. CONCLUSIONS: EUS may become a mandatory modality for differentiating pancreatic solitary cystic tumors and choosing an optimal treatment.

Adenocarcinoma↗
PubMed1997

Efficacy and safety of preoperative percutaneous transhepatic portal embolization with absolute ethanol: a clinical study.

BACKGROUND: Preoperative portal embolization has been performed by using various thrombogenic substances to increase the safety and resectability of liver surgery. We evaluated the clinical safety and efficacy of using absolute ethanol in preoperative portal embolization. METHODS: Our study included 19 patients who had undergone right hepatic lobectomy. According to our criteria for right lobectomy of the liver, seven patients were not appropriate for the operation because of a high risk in each of postoperative liver failure. Those patients received preoperative right portal embolization with 11 to 32 ml absolute ethanol. The remaining 12 patients satisfied our criteria and received no preoperative embolization. RESULTS: Although alanine aminotransferase concentrations increased dramatically after the embolization, all serologic changes reverted within 3 weeks. The mean volume of the nonembolized lobe increased from 320 cm3 to 619 cm3 and 667 cm3 2 and 4 weeks, respectively, after embolization. The mean regeneration rate of this lobe was 21.3 cm3 per day for the first 2 weeks and 11.4 cm3 per day for the first 4 weeks after embolization. All patients underwent right lobectomy of the liver and survived; none of the patients had severe complications associated with embolization or surgery. The postoperative survival periods were not statistically significant between the patients with and without preoperative portal embolization. CONCLUSIONS: According to our criteria for liver surgery, the seven patients should not have undergone major surgery, but each underwent right lobectomy of the liver and all survived, showing that portal embolization with absolute ethanol brings about compensatory hepatic hypertrophy for major surgery and that its extreme effect on liver regeneration could widen the range of patients appropriate for liver surgery.

Adult↗
PubMed1997

Inflammatory pancreatic masses: differentiation from ductal carcinomas with contrast-enhanced sonography using carbon dioxide microbubbles.

OBJECTIVE: The aim of this study was to evaluate the clinical efficacy of contrast-enhanced sonography using carbon dioxide microbubbles to differentiate inflammatory pancreatic masses from ductal carcinomas of the pancreas. SUBJECTS AND METHODS: Fifty-five patients, including 35 patients with ductal carcinomas and 20 with inflammatory pancreatic masses, underwent contrast-enhanced sonography, CT, and digital subtraction angiography (DSA). Carbon dioxide microbubbles were prepared by mixing 10 ml of carbon dioxide and the same amount of 25% soybean oil vigorously. Carbon dioxide microbubbles were injected through an angiographic catheter that was placed in the celiac axis. Vascularity of the tumors as determined by those three techniques was interpreted by three physicians who had no knowledge of the pathologic results. RESULTS: Contrast-enhanced sonography was best at revealing tumor vascularity among the three techniques. On contrast-enhanced sonography, 19 (95%) of the 20 inflammatory pancreatic masses were isovascular and 32 (91%) of the 35 ductal carcinomas were hypovascular. In contrast, the isovascularity of inflammatory masses was five (25%) on CT, and two (10%) on DSA, respectively. The sensitivity and accuracy rate of differentiating both diseases on contrast-enhanced sonography were 98% and 95%, respectively; on CT, they were both 73%; and on DSA they were both 67%. From our results, an isovascular mass is probably an inflammatory mass, whereas a hypovascular mass is most likely a ductal carcinoma on contrast-enhanced sonography. CONCLUSION: Contrast-enhanced sonography can help differentiate an inflammatory pancreatic mass from a ductal carcinoma.

Adenocarcinoma↗