Mucin-producing tumor of the pancreas--intraluminal ultrasonography.

BACKGROUND/AIMS: Many patients with mucin-producing pancreatic tumor, characterized by dilatation of the pancreatic duct, are diagnosed by conventional ultrasonography in a mass ultrasonographic survey in Japan. It is a necessary and reliable method for making a precise diagnosis and for deciding on the treatment approach. Endoscopic ultrasonography (EUS) is appreciated as a useful method for precise diagnosis of pancreatic tumors. Intraductal ultrasonography (IDUS) is expected to be a new modality for the more detailed diagnosis of pancreatic tumors. METHODOLOGY: Endoscopic ultrasonography and intraductal ultrasonography were performed in 23 patients with mucin-producing pancreatic tumor. The differences in ultrasonographic findings between benign and malignant tumors were studied. RESULTS: Ultrasonographic findings of mucin-producing pancreatic tumor revealed by EUS and IDUS were: cystic lesion, mural nodule in the cystic lesion, wall thickness of the cyst, mucus echoes, and solid tumor with a mixed echo pattern. Seven out of 11 patients with mural nodule were diagnosed as carcinomas and another 4 patients had adenoma. Seven of 8 patients with mucus echoes were diagnosed as carcinoma. Three of 4 patients with solid tumor were diagnosed as invasive carcinoma. The ultrasonographic findings suggesting malignancy were: mural nodule, irregular wall thickness, mucus echoes, and solid tumor with a mixed pattern. Solid tumor indicated invasive carcinoma exclusively. CONCLUSIONS: Intraluminal ultrasonography, EUS and IDUS are very useful in making a differential diagnosis between benign and malignant tumors in mucin-producing pancreatic tumors.

Ras gene point mutations in gallbladder lesions associated with anomalous connection of pancreatobiliary ducts.

BACKGROUND/AIMS: The present study was undertaken to investigate possible changes in the K-ras oncogene in patients with gallbladder lesions (carcinoma, adenoma or hyperplasia) in relation to the presence or absence of an anomalous connection of pancreatobiliary ducts (ACPBD). METHODOLOGY: Gallbladder specimens were obtained from 44 patients with lesions that were either with or without ACPBD, and DNA samples were analyzed using PCR-SSCP. Point mutations in codons 12, 13 and 61 were analyzed by direct sequencing methods with oligonucleotide primers. RESULTS: The K-ras codon 12 was detected in 83.3% (5/6) of carcinomas the one adenoma tested and in 35.7% (5/14) of hyperplastic lesions with ACPBD, as opposed to only 36.4% (4/11) of carcinomas without ACPBD. The one case of gallbladder adenoma and 11 cases of normal gallbladder without ACPBD studied demonstrated no point mutations in the K-ras oncogene. CONCLUSIONS: Alteration of the K-ras oncogene appears to be involved in the early stages of gallbladder carcinogenesis when in association with ACPBD. The results further suggest that hyperplasia in cases with ACPBD may be a significant pre-cancerous lesion.

[The studies of extracorporeal shock wave lithotripsy (ESWL) for pancreatic ductal stones].

30 patients with main pancreatic duct stones were treated by ESWL. In 18 of 22 patients who had not previously undergone endoscopic pancreatic sphincterotomy (EPST) or endoscopic sphincterotomy (EST), the stone fragments disappeared after ESWL. The fragments were removed endoscopically in the remaining 4 cases. Complete clearance was achieved in 8 cases with endoscopically unextractable stones by ESWL. After the ESWL procedure, absolute relief from pain was reported by in 19 of 22 patients with abdominal complaints. Serum amylase levels decreased significantly, and dilatation of the main pancreatic duct (MPD) was reduced. In the medium-term follow-up period, pancreatic exocrine function and endocrine function had a possibility to be preserved. One case of pancreatic cancer and one case of an intraductal papillary tumor of the pancreas were found, indicating that careful observation is necessary even after complete removal of pancreatic stones. In cases of Santorini duct dominant, multiple stones, or stricture of the MPD, ESWL should be combined with EPST and endoscopic stenting for preventing recurrence of acute pancreatitis and pancreatic stones. In conclusion, ESWL is the first choice of treatment for pancreatolithiasis and useful procedure and the limited complications.

Endoscopic MRI: preliminary results of a new technique for visualization and staging of gastrointestinal tumors.

BACKGROUND AND STUDY AIMS: The principle of endoscopic ultrasonography--introducing the transducer of an external imaging method, such as ultrasonography, in combination with an endoscope into the gastrointestinal tract for higher-resolution imaging--has also been applied to magnetic resonance imaging (MRI). We report here on our preliminary experience with a new method of endoscopic MRI in the upper gastrointestinal tract. PATIENTS AND METHODS: Endoscopic MRI was performed in 32 patients with esophageal (n = 8) or gastric diseases (n = 24), mostly tumors (n = 26). Most cancers were at an advanced stage (T3/T4). A prototype MRI endoscope connected to a 1.5 tesla MRI scanner was used. The accuracy of endoscopic MRI in visualizing and staging gastrointestinal lesions was assessed. RESULTS: The normal gastrointestinal wall consisted of three layers, and tumors were visualized as having a low signal intensity on both T1- and T2-weighted sequences. Destruction of the wall layers was found to be characteristic of malignancy. Sufficient images were obtained in seven of eight esophageal cases (88%), but in only 14 of 24 gastric cases (58%). In patients in whom adequate visualization was achieved, the endoscopic MRI results of local and regional staging were consistent with surgical, histopathological, CT and/or EUS results in all six esophageal cancer cases and in 89% (T stage) and 56% (N stage) of the nine patients with gastric cancer. CONCLUSIONS: These preliminary results of endoscopic MRI are the first to be reported in the English literature. They show the potential of the method for local and regional staging, three-dimensional visualization of lesions being a potential advantage. Further technical improvements are expected.

[A study of the relationship between nocturnal intragastric pH and sleep stages of peptic ulcer].

We studied the correlation of the gastric acid secretion and the depth of sleep at night with no medication in 32 cases (19 gastric ulcer, 6 duodenal ulcer patients and 7 healthy controls). Using Memory PH: Monitor intragastric pH values were consecutively measured without antiulcer drugs. The depth of sleep were monitored continuously by recording without any sleeping drugs. In healthy controls, the pH values of awake phase was significantly lower than that of sleep stage 1, 4 and rapid eye movement (REM) phases. The pH values of REM phases were significantly high rather than that of sleep stage 1 and 2 phases. In patients with gastric ulcer, the pH values of awake phases were significantly lower than that of sleep stage 1 and REM phases. The pH values of REM phases were significantly high rather than that of the other sleep stages. On the other hand, in patients with duodenal ulcer, the obvious changes of the pH values were not seen with sleep stages. The pH values of healthy controls and gastric patients were changed with sleep stages. But the pH of duodenal ulcer patients were not changed obviously. Therefore, it is suggested that the dysfunction of autonomous nervous system was influenced the nocturnal intragastric pH in the patients with duodenal ulcer and played one of the important role in the occurrence of duodenal ulcer.

Gastric ulcer: can endoscopic ultrasonography predict healing?

The course of healing of gastric ulcers and their relapse were examined, based on observation of the cross-sections of gastric ulcers using endoscopic ultrasonography. This study concludes that EUS can predict ulcer healing and it is suggested that the strategy be planned based on the findings from EUS.

[Diagnostic strategy for malignancy and parenchymal invasion of so-called mucin-producing tumor of the pancreas].

This study investigated diagnostic indications of malignancy and parenchymal invasion of so-called mucin-producing tumor of the pancreas (MPT). We reviewed 40 patients with this type tumor. In diagnosis of malignancy, jaundice, mural nodule (EUS), displacement or compression of the portal vein (angiography), compression of the common bile duct (cholangiography) and Group IV-V in biopsy, Class III-V in brushing cytology were important. In diagnosis of parenchymal invasion, solid mass (US, EUS, CT), arterial encasement (angiography), defect in the common bile duct (cholangiography), stenosis or obstruction of the MPD (pancreatography) and elevation of serum CA19-9, CEA levels were important. By these findings, MPT diagnosed as benign can be observed without surgical treatment. On the other hand, MPT diagnosed as malignant must be treated by surgical resection, and operative procedure must be chosen according to whether the MPT was accompanied by parenchymal invasion or not.

[A study of the influence of gastric acid on the extension of regenerative epithelium of gastric ulcer].

To study the influence of gastric acid on the extension of the regenerative epithelium, 26 patients (28 ulcers) of gastric ulcer were examined by the stereo video-endoscope being able to measure the length and 24-hours intragastric pH monitoring. Extending speeds of the regenerative epithelium were measured from the time the regenerative epithelium of the ulcer was observed till the last examination, but which was limited 8 weeks after the first observation of the regenerative epithelium. The relationship was not observed between the extending speeds and the stages (A2-H1, H1-H2, H2-S1) of the ulcer. For 21 ulcers followed up by the stereo video-endoscope from active stage, the extending speed of the regenerative epithelium and the pH 3 holding time in a day were significantly correlated (r = 0.51, p = 0.014), and the same relationship (r = 0.56, p = 0.008) were observed in the nighttime. It was confirmed that the gastric acid regulated strongly the extending speed of regenerative epithelium of gastric ulcer. The intragastric circumstance of the low acid secretion induced by the antacid-drugs was considered to accelerate the extension of regenerative gastric epithelium.

[The effects of synthetic protease inhibitor on motility of the human duodenal papilla].

We studied the effects of synthetic protease inhibitors on the motility of the human duodenal papilla. Before and after the intravenous administration of gabexate mesilate (GM) or nafamostat mesilate (NM), the duodenal papillary pressure was measured with a catheter tip pressure transducer under duodenoscopy. GM was administered to fourteen subjects at 1 and 3 mg/kg/h. The peak pressure and the basal pressure were dose-dependently reduced by GM, but the frequency did not change. The blood CCK concentration was not changed after GM administration. NM was administered to twelve subjects at 0.3 mg/kg/h. Both the papillary pressure and the frequency were not changed by NM. GM inhibited the papillary motility, but NM had no consistent effect on the papillary motility.

[Extracorporeal shock wave lithotripsy (ESWL) for common bile duct stones].

We treated twenty-three patients with common bile duct stones (12 female, 11 male, mean age: 67.1 years) by Extracorporeal Shock Wave Lithotripsy (ESWL). The stones were focused by ultrasonic or choledochographic localization. The twenty-three patients received 53 ESWL treatments consisting of mean 2357 shocks per treatment at mean 18 kV. We performed ESWL in five cases with endoscopically unextractable common bile duct stones after endoscopic sphincterotomy (EST). In these cases, ESWL permitted stone disintegration and successful endoscopic extraction of the fragments. We performed ESWL in eighteen cases with common bile duct stones without EST. In fifteen of the eighteen cases (83%), fragmentation was achieved. The stone fragments were spontaneously discharged in ten cases (56%) after a median of 4 days following ESWL. In five cases, adjutant endoscopic procedures were performed. The complete fragmentation and the clearance rate for stones of diameter of less than 10 mm were higher than that for stones of diameter of more than 11 mm. In the cases with the stones of diameter of more than 10 mm, there is a very strong possibility that complete clearance is achieved by ESWL alone. No correlation was obtained for the effective results according to pretreatment number of stones. In eight of thirteen cases (62%) with gall bladder stones, complete clearance was achieved without EST. ESWL without EST can be thought as a rational treatment for preserving the function of papilla of Vater in the case of cholecysto-choledocholithiasis.

[Comparative study of extracorporeal shock wave lithotripsy (ESWL) between spark gap system and piezoelectric system].

We have analyzed the results of the treatment given on 170 cases of cholecystolithiasis, using two different systems of ESWL: Spark Gap System (hereinafter SGS) and Piezoelectric System (hereinafter PES). 1) In the total cases, there were no significant differences in the fragmentation rate between the two systems. PES was, however, superior to SGS in terms of the complete stone free rate. On the other hand, SGS was superior to PES in terms of the average fragmentation rate. 2) We have classified cholecystolithiasis into 4 groups, combining CT and US. PES showed superiority in the ESWL Group 1 (seeming Pure Cholesterol Stone) and Group 2 (seemingly Mixed Stone) in terms of stone free rate. SGS showed superiority in ESWL Group 3 (seemingly Combination Stone) and Group 4 (seemingly Pigment Stone) in terms of fragmentation effect. 3) We have gained good results from both of the system according to Munich Criteria Modified. 4) Concerning the failures of fragmentation and insufficient stone free, further study shall be required to determine whether fragmentation should be repeated, the case should be handled as "beyond adaptability", or the two-system-combined therapy should be applied.

[Endoscopic ultrasonographic study of gastric ulcer treated with proton pump inhibitor].

We examined 70 cases of gastric ulcer by endoscopic ultrasonography. Of these, 18 cases were treated with proton pump inhibitor (PPI), another cases were treated with histamine H2 receptor antagonist or mucosal protective drugs. The Endoscopic cumulative healing rate at the eighth week was 71.4% in all gastric ulcers. On the other hand, all of gastric ulcers treated with PPI were healed within eight weeks endoscopically. Gastric ulcers which were revealed ultrasonographically to be refractory with were healed by PPI therapy. The length of the ulcer echo in gastric ulcers treated with PPI was shorter than that in gastric ulcer treated by other drugs. In spite of endoscopic scar findings, a wide ulcer echo was observed in some cases.

[A study on the new measurement of gastric lesions with an electronic endoscope].

We carried out measurement of gastric lesions in the inner surface of the stomach with a measuring system, which is composed of a stereo endoscope and a personal computer. Basically, the length on a flat board from 10 mm to 50 mm was measured by varying the distance between the lens and the board and the angles of the endoscope at first. The error of the measurement was less than 8.5%. Secondly, ten physicians of our clinic attempted the measurement of the pasted discs on the inner wall of a stomach model with the endoscope. The average measurement error and the average time required for endoscopy became more better using the newly developed system than a measuring rod. Clinically, we measured the length of stomach lesion and of normal mucosa in six patients and compared the values obtained with those of resected fresh specimens. The length of stomach lesions could be measured more accurately than that of normal mucosa of stomach. From our observations, it can be said that this system is as available as the basic examination procedures in use at present and worth using in clinical procedure for it's high reliability.