Jun Horaguchi

Mode of progression of intraductal papillary-mucinous tumor of the pancreas: analysis of patients with follow-up by EUS

BackgroundWe investigated the mode of progression of intraductal papillary-mucinous neoplasm of the pancreas (IPMN) in patients who underwent follow-up in order to elucidate the characteristics of malignancy and to establish an effective treatment strategy.MethodsFifty-one patients with IPMN (branch-duct type, 47; main-duct type, 4) who had undergone follow-up study by endoscopic ultrasonography (EUS) were included (mean follow-up duration, 41.0 ± 32.3 months; average number of EUS examinations performed during follow-up, 4.4). Chronological changes in EUS findings and histological findings of resected specimens were evaluated.ResultsOf the patients with the branch-duct type, only 2% showed enlargement of the dilated branches. In the main-duct-type group, an increase in size of the main pancreatic duct (MPD) was observed in 75% of the patients. In 14 patients with papillary protrusions, an increase in size and lateral spread was observed in 71% and 43%, respectively. No patients developed invasive cancer. In 15 patients who had thick septum-like structures (TSS), the development of papillary protrusions and that of invasive cancer were observed in 53% and 13%, respectively. Twenty-nine patients who had thin septum-like structures showed no change. Two patients with dense multilocular large cysts and TSS developed invasive cancer without change in the cystic lesions. One patient developed carcinoma with multifocal stromal invasion.ConclusionsPatients with branch-duct type IPMNs without papillary protrusions or TSS are not immediate candidates for surgery. Those who have small papillary protrusions have a benign course. It is recommended that patients with the large branch-duct type with TSS should undergo surgery. Attention should be paid to the entire pancreas when performing follow-up examinations in patients with branch-duct type IPMN, as invasive ductal adenocarcinoma can develop at a site in the pancreas different from that of the IPMN.

Impact of a transparent hood on the performance of total colonoscopy : a randomized controlled trial

BACKGROUND Clinical demand for total colonoscopy (TCS) is increasing. Improvement of the cecal intubation rate and shortening of the examination time would expand the capacity for TCS. OBJECTIVE To assess the efficacy of a transparent hood attached to the tip of a colonoscope for cecal intubation in TCS. DESIGN Prospective, randomized, controlled study. SETTING Single tertiary-referral center. INTERVENTIONS TCS. MAIN OUTCOME MEASUREMENTS Cecal intubation time and rate, complications, patient discomfort, and detection rate of colonic polyps. METHODS Patients who were to undergo screening and/or surveillance TCS for colorectal cancer were invited to participate in the study. Cecal intubation time and rate, complications, patient discomfort, and detection rate of colonic polyps were evaluated. RESULTS A total of 592 patients enrolled in this study were randomly allocated to the hood group and no-hood group. The mean (SD) cecal intubation time in the hood group and the no-hood group was 10.2 +/- 12.5 minutes and 13.4 +/- 15.8 minutes, respectively (P = .0241). The effect of its use was more prominent in the expert endoscopists group compared with those with moderate experience. The cecal intubation rate and the detection rate of small polyps in the 2 groups were similar. The grade of patient discomfort was significantly lower in the hood group. No complications were encountered with the use of the hood. CONCLUSIONS Use of a transparent hood on the tip of a colonoscope shortened the time required for cecal intubation and decreased patient discomfort; such use was more effective among experts in shortening the examination time.

ENDOSONOGRAPHY-GUIDED BILIARY DRAINAGE IN CASES WITH DIFFICULT TRANSPAPILLARY ENDOSCOPIC BILIARY DRAINAGE

Background:  Recently, reports on a new endoscopic biliary drainage technique utilizing endosonographic guidance (endosonography‐guided biliary drainage [ESBD]) have been increasing. The aim of this study was to evaluate the efficacy of ESBD in cases with difficult transpapillary endoscopic biliary drainage (EBD).

Therapeutic endoscopic retrograde cholangiopancreatography using an anterior oblique-viewing endoscope for bile duct stones in patients with prior Billroth II gastrectomy

BackgroundPrior Billroth II gastrectomy is an important factor presenting difficulties in endoscopic retrograde cholangiopancreatography (ERCP) administration. We retrospectively evaluated the usefulness and safety of therapeutic ERCP using an anterior oblique-viewing endoscope for bile duct stones in patients with prior Billroth II gastrectomy.MethodsForty-three patients with bile duct stones after Billroth II gastrectomy who underwent ERCP from January 1998 to February 2008 were enrolled in this study. We used anterior oblique-viewing endoscopes for all procedures. Endoscopic sphincterotomy was performed using a needle knife guided by a biliary stent. A total of 808 patients without gastrectomy who had undergone ERCP for bile duct stones in the same period were reviewed as controls.ResultsThe success rate of access to the papilla of Vater was 88.4%, and the average time required for such access was 13 min. In cases of successful access, selective cannulation of the bile duct and complete stone removal were achieved in 94.7% and 94.6% of patients, respectively. The incidence of complications was 4.7%. As for the success rate of selective cannulation, complete stone removal ratio, and the incidence of complications, there were no significant differences compared with the control group.ConclusionsUse of an anterior oblique-viewing endoscope enables good success rates in selective cannulation and complete stone removal to be achieved in patients with prior Billroth II gastrectomy. The safety of therapeutic ERCP for removal of bile duct stones in those patients is comparable to that in patients with normal anatomy.

Intraductal papillary mucinous neoplasms of the pancreas showing fistula formation into other organs

BackgroundThis study assessed the mechanism of fistula formation in intraductal papillary mucinous neoplasm (IPMN) of the pancreas.MethodsA total of 274 patients with IPMN who had been diagnosed by endoscopic retrograde cholangiopancreatography and endoscopic ultrasonography (EUS) at our center were enrolled. The patients with IPMN which had fistula formation into other organs were investigated retrospectively as to (1) clinical prevalence and the organs penetrated by IPMN, (2) analysis of the mechanism of fistula formation by immunohistopathological study, (3) efficacy of EUS in progression assessment, and (4) prognosis.ResultsAmong the subjects, fistula formation into other organs was observed in 18 patients (6.6%) and into 28 organs. There were 7 patients (39%) in whom multiple organs were penetrated. Of 16 patients who had undergone investigation of the expression of mucin markers, 94% had an intestinal-type tumor. Of 9 patients who had undergone surgery or autopsy, 67% showed mechanical penetration without invasion around the fistula. Only papillary protrusions were seen by EUS in 4 of these patients with noninvasive papillary adenocarcinoma showing mechanical penetration. All 5 patients who had pancreatic parenchymal invasion showed a mass with a mixed-echo pattern in addition to papillary protrusions shown by EUS, corresponding to colloid carcinoma.ConclusionsThere were 2 processes in the development of fistulas in IPMN. Of those patients showing fistula formation, 94% had intestinal-type IPMN, and 67% showed mechanical penetration. Delineation of a mass with the mixed-echo pattern suggested an invasive penetration due to colloid carcinoma.

Case of early ampullary cancer treated by endoscopic papillectomy

We herein report a case of ampullary cancer in a 65‐year‐old man who underwent endoscopic papillectomy. Duodenoscopy revealed an exposed‐type tumor mass at the ampulla of Vater. Histology of the biopsy specimen demonstrated well‐differentiated adenocarcinoma. Endoscopic ultrasonography and intraductal ultrasonography showed a hypoechoic mass limited to the ampulla of Vater (clinical stage, T1). Endoscopic papillectomy was performed after informed consent was obtained. Histological examination of the resected specimen revealed adenocarcinoma limited to the ampulla of Vater (final stage, pT1). Both accurate preoperative T staging and proper histological evaluation of the resected specimen appear to justify endoscopic treatment of early ampullary cancer.

Clinical study of choledochocele: is it a risk factor for biliary malignancies?

BackgroundWe aimed to clarify the clinical characteristics of choledochocele and to evaluate the possibility of choledochocele as a risk factor for biliary malignancies.MethodsThe clinical feature, the configuration of the pancreatobiliary ductal system, coexistent pancreatobiliary lesions, and amylase level in bile in 21 patients with choledochocele were reviewed. The correlation between the configuration, comorbid diseases, and amylase level in the bile was investigated.ResultsThere was a female predominance, and 57% of the patients showed abdominal pain. Quite a few patients showed elevation of the levels of hepatobiliary enzymes. The configuration of the pancreatobiliary ductal system and choledochocele was classified into two categories: type I, where the choledochocele and pancreatic duct were visualized independently or simultaneously (90.5%); and type II, where the pancreatic duct was visualized after filling of the choledochocele (9.5%). Among coexistent bilio-pancreatic diseases, biliary stone diseases were the most frequent. Biliary malignancy was seen in 3 patients (14.3%). The amylase level in the bile was high in 50% (4/8) of the patients examined. The rate of abnormal elevation of amylase level in the bile in the two types of pancreatobiliary ductal system and choledochocele was 3/7 and 1/1, respectively.ConclusionsThe prevalence of organic abnormal arrangement of the pancreatobiliary ductal system in which the choledochocele serves as a common channel is low. However, there are patients with suspected functional abnormal arrangement of the pancreatobiliary ductal system, who may possibly be a high-risk group for biliary malignancy.

Solid cystic tumor of the pancreas: report of six cases and a review of the Japanese literature

Although many cases of solid cystic tumor of the pancreas (SCT) have been reported, its nature and histogenesis remain controversial. We herein report six cases of SCT, including three cases of noncystic type. A review of 22 cases of noncystic type SCT, including our 3 cases, was carried out to compare their features with those of 173 cases of classic SCT reported in Japan. Noncystic type SCTs tend to occur in male patients and are smaller in size and less frequently symptomatic, although they show histological characteristics similar to those of classic SCTs. The developmental process might be a cause of cyst formation. The accumulation and analysis of many, at present, “atypical” cases for clarification of its nature, will, it is hoped, lead to a new nomenclature for this condition that adequately describes its biological origin.

Modes of spread in early ampullary cancer in terms of establishing proper indications for endoscopic papillectomy

Background:  Endoscopic papillectomy for adenomas of the ampulla of Vater has been reported and is gaining acceptance as an alternative to surgery in the treatment of early ampullary cancer. However, whether endoscopic treatment is justified as a treatment of choice for early ampullary cancer remains controversial. The aim of the present study was to elucidate the possibility of endoscopic papillectomy as a treatment of early ampullary cancer from the review of pathology of cases treated by surgical resection.

Temporary endosonography-guided biliary drainage for transgastrointestinal deployment of a self-expandable metallic stent

Endosonography-guided biliary drainage (ESBD) is now gaining acceptance as a useful alternative for the management of obstructive jaundice.1 At present, ESBD is used mainly to establish an anastomosis between the biliary tree and the duodenum, stomach, jejunum, or esophagus by placing a stent so as to bridge the bile duct and alimentary tract. We herein report a new application of ESBD, that is, its temporary use for gaining access to the bile duct in order to deploy a self-expandable metallic stent (SEMS) via the transhepatic route. In a patient with pylorus stenosis due to advanced gastric cancer with extrahepatic bile duct obstruction caused by nodal metastasis, a plastic stent was placed temporarily by ESBD to bridge the esophagus and the left hepatic duct. Ten days later, the stent was retrieved, leaving a guidewire in the bile duct, and a delivery unit of a SEMS was introduced into the bile duct over the guidewire via the sinus tract. The SEMS was then successfully deployed through the stenosis. No stent was left in the sinus tract. This procedure yields a mature fistula through which a delivery unit can be safely introduced into the bile duct followed by uneventful deployment of a SEMS.