[A case of duodenal perforation due to ingested fishbone with retroperitoneal abscess formation where surgical drainage was necessary after endoscopic removal].

A female in her 60s was referred to our institution with epigastric pain and abdominal fullness persisting for one week. She was afebrile and mild abdominal tenderness was found on physical examination. Computed tomography (CT) revealed free air, and the dirty fat sign outside the duodenal wall. Her previous CT had not shown causative findings such as duodenal diverticula. A slightly high-attenuated linear structure penetrating the duodenal wall at the second portion was suspected after review of present CT images. Based on the history of her current illness, the possibility of mackerel bone ingestion was considered. Esophagogastroduodenoscopy (EGD) revealed a fishbone sticking out of the duodenal wall, which was extracted with biopsy forceps. Although antibiotic treatment under fasting was continued, the formation of retroperitoneal abscess was detected by CT on the 6th postprocedural day. Given that she also developed a high fever, surgical drainage was performed. The patient was discharged on the 15th postoperative day. Thus, in cases of duodenal perforations, a fishbone should be taken into account as a possible cause. Even if endoscopic removal was initially selected, careful observation is mandatory and an additional treatment should be considered depending on the clinical course.

Brief Report: Emotional Picture and Language Processing in Adults with Autism Spectrum Disorder.

There is currently limited research and a lack of consensus on emotional processing impairments among adults with autism spectrum disorder (ASD). The present pilot study sought to characterize the extent to which adults with ASD are impaired in processing emotions in both words and pictures. Ten adults with ASD rated word and picture stimuli on emotional valence and arousal. Their ratings were compared to normative data for both stimuli sets using item-level correlations. Adults with ASD rank-ordered stimuli similarly to typically developing individuals, demonstrating relatively typical understanding of emotional words and pictures. However, they used a narrower range of the scales which suggests more subtle impairments affecting emotion-processing. Future directions arising from the findings of this pilot study are discussed.

[A case of circumferential rectal wall thickening caused by prostate cancer invasion concomitant with ischemic colitis].

A man in his 70s presented to Kyojinkai Komatsu Hospital with lower left abdominal pain and hematochezia after repeated use of laxatives. Computed tomography (CT) revealed continuous bowel wall thickening from the descending colon to the rectum. The symptoms and CT findings were consistent with ischemic colitis. The patient's condition improved with conservative treatment. However, the patient was reexamined 3 months later because complaints of constipation and voiding difficulty continued. Colonoscopic findings revealed rectal stenosis and reddish edematous mucosa with nodular alterations. Although CT showed that the abnormality in the descending and sigmoid colon had resolved, the wall thickening and annular stricture of the rectum persisted. The prostate was irregularly enlarged, encircling and compressing the rectum. Rectal biopsy results did not reveal malignancy. However, moderately to poorly differentiated adenocarcinoma was detected by prostate biopsy. Consequently, the patient was diagnosed with prostate cancer with rectal involvement. The rectal wall thickening and the symptoms improved following hormone therapy. Thus, concomitant prostate cancer invasion should be considered when CT reveals continuous colon wall thickening up to the rectum in a patient suspected of ischemic colitis.

Overlapping attentional networks yield divergent behavioral predictions across tasks: Neuromarkers for diffuse and focused attention?

Attention is a critical cognitive function, allowing humans to select, enhance, and sustain focus on information of behavioral relevance. Attention contains dissociable neural and psychological components. Nevertheless, some brain networks support multiple attentional functions. In this study, we used the visual attentional blink (VAB) as a test of the functional generalizability of the brain's attentional networks. In a VAB task, attention devoted to a target often causes a subsequent item to be missed. Although frequently attributed to limitations in attentional capacity or selection, VAB deficits attenuate when participants are distracted or deploy attention diffusely. The VAB is also behaviorally and theoretically dissociable from other attention tasks. Here we used Connectome-based Predictive Models (CPMs), which associate individual differences in task performance with functional connectivity patterns, to test their ability to predict performance for multiple attentional tasks. We constructed visual attentional blink (VAB) CPMs, and then used them and a sustained attention network model (saCPM; Rosenberg et al., 2016a) to predict performance. The latter model had been previously shown to successfully predict performance across tasks involving selective attention, inhibitory control, and even reading recall. Participants (n â€‹= â€‹73; 24 males) underwent fMRI while performing the VAB task and while resting. Outside the scanner, they completed other cognitive tasks over several days. A vabCPM constructed from VAB task data (behavior and fMRI) successfully predicted VAB performance. Strikingly, the network edges that predicted better VAB performance (positive edges) predicted worse performance for selective and sustained attention tasks, and vice versa. Predictions from applying the saCPM to the data mirrored these results, with the network's negative edges predicting better VAB performance. The vabCPM's positive edges partially yet significantly overlapped with the saCPM's negative edges, and vice versa. Many positive edges from the vabCPM involved the default mode network, whereas many negative edges involved the salience/ventral attention network. We conclude that the vabCPM and saCPM networks reflect general attentional functions that influence performance on many tasks. The networks may indicate an individual's propensity to deploy attention in a more diffuse or a more focused manner.

Do enhanced states exist? Boosting cognitive capacities through an action video-game.

This research reports the existence of enhanced cognitive states in which dramatic temporary improvements in temporal and spatial aspects of attention were exhibited by participants who played (but not by those who merely observed) action video-games meeting certain criteria. Specifically, Experiments 1 and 2 demonstrate that the attentional improvements were exhibited only by participants whose skills matched the difficulty level of the video game. Experiment 2 showed that arousal (as reflected by the reduction in parasympathetic activity and increase in sympathetic activity) is a critical physiological condition for enhanced cognitive states and corresponding attentional enhancements. Experiment 3 showed that the cognitive enhancements were transient, and were no longer observed after 30 min of rest following video-gaming. Moreover, the results suggest that the enhancements were specific to tasks requiring visual-spatial focused attention, but not distribution of spatial attention as has been reported to improve significantly and durably as a result of long-term video-game playing. Overall, the results suggest that the observed enhancements cannot be simply due to the activity of video-gaming per se, but might rather represent an enhanced cognitive state resulting from specific conditions (heightened arousal in combination with active engagement and optimal challenge), resonant with what has been described in previous phenomenological literature as "flow" (Csikszentmihalyi, 1975) or "peak experiences" (Maslov, 1962). The findings provide empirical evidence for the existence of the enhanced cognitive states and suggest possibilities for consciously accessing latent resources of our brain to temporarily boost our cognitive capacities upon demand.

Successful laparoscopic cholecystectomy for acute cholecystitis with kyphoscoliosis by the devised placement of trocar ports: A case report.

INTRODUCTION: Kyphoscoliosis, which is a deformity of the spine caused by aging and osteoporosis, results in various surgical difficulties for laparoscopic cholecystectomy (LC) due to low-lying costal arches, such as a small abdominal working space, disturbance of the surgical view and decreased controllability of the surgical instrument. PRESENTATION OF CASE: We herein report the case of a 92-year old woman with severe kyphoscoliosis who was diagnosed with Grade II acute cholecystitis. Taking her general status into consideration, emergency percutaneous transhepatic gallbladder drainage (PTGBD) was initially performed. After PTGBD, the patient's physical status and systemic inflammation markedly improved. She then underwent interval LC. The surgical view of the upper abdomen including the gallbladder was entirely interrupted by bilateral low-lying costal arches with adhesion to the greater omentum. To access the gallbladder without interruption by the low-lying costal arch, the first umbilical port was changed to a multi-port with surgical glove and an additional port was added in the left abdomen. Consequently, LC was safely accomplished with the creation of the critical view. DISCUSSION: A low-lying costal arch due to kyphoscoliosis can prevent surgeons from accessing the gallbladder. LC with the standard 4-port method could not be accomplished because of insufficient lifting of the low-lying costal arch. Devised placement of the ports is needed to access the gallbladder between bilateral low-lying costal arches. CONCLUSION: A transumbilical multi-port and left abdominal port may be effective for successful LC of acute cholecystitis with kyphoscoliosis.

A Case of Malignant Biliary Obstruction with Severe Obesity Successfully Treated by Endoscopic Ultrasonography-Guided Biliary Drainage.

Here, we present a case of malignant biliary tract obstruction with severe obesity, which was successfully treated by endoscopic ultrasonography-guided biliary drainage (EUS-BD). A female patient in her sixties who had been undergoing chemotherapy for unresectable pancreatic head cancer was admitted to our institution for obstructive jaundice. She had diabetes mellitus, and her body mass index was 35.1 kg/m2. Initially, endoscopic retrograde cholangiopancreatography (ERCP) was performed, but bile duct cannulation was unsuccessful. Percutaneous transhepatic biliary drainage (PTBD) from the left hepatic biliary tree also failed. Although a second PTBD attempt from the right hepatic lobe was accomplished, biliary tract bleeding followed, and the catheter was dislodged. Consequently, EUS-BD (choledochoduodenostomy), followed by direct metallic stent placement, was performed as a third drainage method. Her postprocedural course was uneventful. Following discharge, she spent the rest of her life at home without recurrent jaundice or readmission. In cases of severe obesity, we consider EUS-BD, rather than PTBD, as the second drainage method of choice for distal malignant biliary obstruction when ERCP fails.

A case of hepatic inflammatory pseudotumor protruding from the liver surface.

We report a case of a resected hepatic inflammatory pseudotumor (IPT) protruding from the liver surface. A 69-year-old male with diabetes mellitus was admitted to hospital for investigation of an hepatic mass. An irregularly shaped, low-echoic mass measuring 21 × 18 mm was identified by ultrasound in S6. On computed tomography, the tumor appeared to be growing extrahepatically. After contrast enhancement, the lesion showed persistent peripheral enhancement, while the central part was hypoenhanced. On T2-weighted magnetic resonance imaging (MRI), the central portion of the lesion was hyperintense compared with the periphery. EOB-enhanced MRI revealed the mass to be being hypointense in contrast to the surrounding liver parenchyma in the hepatobiliary phase. On diffusion-weighted images, the lesion was hyperintense. Percutaneous biopsy was not attempted to avoid tumor cell dissemination. The patient underwent partial hepatectomy because of suspected malignancy. Histopathological examination of the resected specimen revealed fibrotic tissue and abundant vessels in the periphery, while a massive infiltration of inflammatory cells and fewer vessels were observed in the center. The patient was finally diagnosed with hepatic IPT of the fibrohistiocytic type.

Clinicopathological study on endocrine cell micronests associated with early gastric cancer.

OBJECTIVE: The purpose of this study was to review cases of early gastric cancer associated with Endocrine cell micronests (ECM) and investigate the incidence and characteristics of these lesions. METHODS: A total of 482 patients who had undergone endoscopic or surgical resection for gastric epithelial neoplasms from April 2008 to March 2010 were enrolled in this study. After detection of ECM in the lamina propria mucosa by histological examination of the resected specimens with hematoxilin-eosin staining, immunostaining was also performed. Clinical manifestation and endoscopic findings, as well as histological findings, were examined. RESULTS: Among the 482 patients, 5 (1.0%) had ECM. The histological type of gastric epithelial cancers associated with ECM was tubular adenocarcinoma and carcinoma in situ (Tis) in the WHO classification in all 5 cases. ECM were round to oval or trabecular and located within the area of the early gastric cancer in all the 5 cases. The background gastric mucosa was Type A gastritis in 2 patients and ordinary atrophic gastritis in 2 patients. In the other case, it was difficult to determine the type of gastritis. CONCLUSION: ECM developed not only from the background of Type A gastritis but also from ordinary atrophic gastritis. ECM coexistent with gastric cancer were present in 1.0% of resectable gastric epithelial neoplasms.

Prospective evaluation of contrast-enhanced computed tomography for the detection of colonic diverticular bleeding.

BACKGROUND AND AIMS: To prospectively evaluate the role of contrast-enhanced computed tomography (CE-CT) in the detection of colonic diverticular bleeding (CDB). PATIENTS AND METHODS: Consecutive patients who presented with hematochezia and were clinically suspected of CDB were prospectively enrolled. Those who could undergo both CE-CT and total colonoscopy, and who were finally diagnosed as CDB, were included in the analysis. RESULTS: Fifty-two cases were finally included in the analysis. The detection rate of CDB by CT was 15.4 % (8/52). Univariate analysis showed that the interval from the latest episode of hematochezia to the performance of CT and the presence of a past history of CDB were contributing factors for detection. The interval was 1.6 ± 4.6 h (mean ± SD) in patients detected by CT, and 3.4 ± 3.2 h in those without detection. The detection rate of CDB by total colonoscopy was 38.5 % (20/52). The overall detection rate was 46.2 % (24/52), which was superior to what CT or colonoscopy alone achieved. CONCLUSIONS: CE-CT may play a complementary role to colonoscopy in patients with suspected CDB, but is not recommended for all cases due to its low detection rate. Patients who can be examined within 2 h of last hematochezia would be candidates for urgent CT.

A case of mucosal cancer of the stomach treated by endoscopic submucosal dissection after which nodal metastasis became evident.

An 82-year-old male was referred to our institution for evaluation and treatment of a protruding lesion in the stomach. Esophagogastroduodenoscopy (EGD) showed a small protruding lesion and a large superficial elevated lesion on the lesser curvature of the stomach (macroscopic type: 0-I and 0-IIa, resp.). CT and endoscopic ultrasonography (EUS) visualized a small round lymph node (LN) 11 mm in size near the lesser curvature, although submucosal invasion was not evident. These two lesions were resected en bloc by endoscopic submucosal dissection (ESD). Pathological examination of the resected specimen showed moderately differentiated tubular adenocarcinoma (tub2) and well-differentiated tubular adenocarcinoma (tub1), respectively, which were limited to the mucosal layer. Because lymphatic-vascular involvement was not detected by hematoxylin and eosin (HE) staining, additional gastrectomy was not performed. Two months after ESD, follow-up EUS and CT showed an enlarged LN. EUS-guided fine needle aspiration (EUS-FNA) for the LN revealed metastasis. Therefore, total gastrectomy with LN dissection was performed. His postoperative course was uneventful. After discharge, he has been followed up at the outpatient department without any sign of recurrence for 5 years. Histological reexamination of the ESD specimen using immunohistochemistry showed lymphatic invasion of cancer cells in the lamina propria of the 0-I lesion 13 mm in size.

Therapeutic endoscopic retrograde cholangiography using a single-balloon enteroscope in patients with Roux-en-Y anastomosis.

BACKGROUND: The aim of the present study was to evaluate the usefulness of a single-balloon enteroscope (SBE) including a newly developed short SBE (SIF-Y0004) for therapeutic endoscopic retrograde cholangiography (ERC) in patients with Roux-en-Y (R-Y) anastomosis. PATIENTS AND METHODS: Therapeutic ERC using a SBE was attempted in 19 cases (41 procedures) with R-Y anastomosis after gastrectomy. A standard SBE (working length of 200 cm, working channel of 2.8 mm) was used in 11 cases (Group L), and a short SBE (working length of 152 cm, working channel of 3.2 mm) was used in eight cases (Group S). RESULTS: Insertion of the scope up to the major papilla was achieved in 79% (15/19) of cases. Average insertion time was 37.0 ± 13.8 min (range, 19-62 min). Bile duct cannulation rate was 79% (11/14) after exclusion of the initial case in which scope exchange was unsuccessful. Average procedure time was78.8 ± 26.9 min (18-119 min). The scheduled therapeutic procedure was completed in 67% (10/15) of the cases (53% [10/19] on an intention-to-treat basis). Cardiorespiratory suppression due to sedative agents resulting in scope withdrawal developed in one procedure (2.4%; 1/41). Although there was no significant difference in therapeutic results between the two groups, the number of procedures was smaller (1.8 ± 1.3 vs 3.6 ± 3.1; P = 0.286) in Group S than in Group L. CONCLUSIONS: Therapeutic ERC using a SBE for patients with R-Y anastomosis is considered to be safe and effective. A short SBE appears to be promising for further improvement in therapeutic results.

Efficacy of acetic acid-spraying method in diagnosing extension of Barrett's cancer under the squamous epithelium.

AIM: Endoscopic diagnosis of the lateral extension of Barrett's cancer under the squamous epithelium (BCUS) is sometimes difficult because the cancer is unobservable in the esophageal lumen. The aim of the present study was to clarify the endoscopic features of the extension of BCUS and verify the usefulness of the acetic acid-spraying method (AAS) for diagnosis. METHODS: A total of 25 patients with Barrett's cancer who had undergone endoscopic resection were included in this study. Histological examination of patients' resected specimens was performed to identify the presence of BCUS. Then, the endoscopic images of the BCUS cases were reviewed to summarize the findings and to evaluate the feasibility of diagnosing the extent of BCUS with each imaging technique. RESULTS: Of the 25 patients, 10 (40%) had BCUS. With white-light imaging, subtle reddish change was observed in the area of BCUS in 80% of the patients, and a flat elevated lesion was recognized in 30%. With narrow band imaging, slight brownish change was observed in the area of BCUS in 86% of the patients. Slight white changes were visualized in all cases with AAS. The extension of BCUS was correctly diagnosed by white-light imaging, narrow band imaging and AAS in 50%, 43% and 100% of the cases, respectively. Histology verified the opening of cancerous glands, which extended under the squamous epithelium, into the esophagus in the area showing slight white changes by AAS. CONCLUSION: AAS can be useful for diagnosing the extension of BCUS.

Prospective randomized controlled study comparing cell block method and conventional smear method for pancreatic juice cytology.

AIM: To elucidate the diagnostic efficacy of the cell block (CB) method by comparing it with that of conventional smear cytology for pancreatic juice obtained by endoscopic retrograde cholangiopancreatography (ERCP) in a randomized controlled trial fashion. METHODS: A total of 170 patients with pancreatic lesions suspicious of being malignant who underwent pancreatic juice collection without giving secretin under ERCP were enrolled in this study. After sampling, the pancreatic juice was randomized to the CB method (n = 85) or to smear cytology (n = 85). CB sections were subjected to hematoxylin-eosin, periodic acid Schiff-Alcian blue, and immunohistochemical stains. Both Papanicolaou stain and Giemsa stain were used for smear cytology. RESULTS: The final diagnosis was malignancy in 54 patients: pancreatic cancer, 45; intraductal papillary-mucinous carcinoma, six; and endocrine tumor, three. The number of patients with a cytological borderline malignancy in the CB group (3.5%) was significantly smaller than that in the smear group (27.1%) (P < 0.001). The diagnostic accuracy of the CB method and that of smear cytology were 76.5% (65/85) and 74.1% (63/85), respectively (P = 0.72), and their respective sensitivities were 50% (14/28) and 38.5% (10/26) (P = 0.39). The sensitivity of the CB method (88.9%) was better than that of smear cytology (42.9%) for invasive ductal carcinoma in the pancreas head (P = 0.048). CONCLUSIONS: The CB method using immunostaining for pancreatic juice cytology showed a much lower rate of equivocal borderline malignancy and a tendency for a higher diagnostic yield compared with smear cytology. Its diagnostic sensitivity, however, was not satisfactory except for pancreatic-head cancer.

Impact of technical modification of endoscopic papillectomy for ampullary neoplasm on the occurrence of complications.

AIM: To evaluate the usefulness of a modified technique of endoscopic papillectomy (EP) for lessening the occurrence of complications. METHODS: Indications for EP were adenoma or well-differentiated adenocarcinoma confined to the papilla of Vater (T1) without tumor spread into the bile/pancreatic duct. Sixteen patients underwent the modified technique, which consists of resection with the Endocut mode, followed by biliary/pancreatic sphincterotomy and stenting (Group A). Twelve patients who had undergone EP, using a cutting current, followed by pancreatic duct stenting were included as control (Group B). The frequency of complications and clinical outcomes were retrospectively compared between the two groups. RESULTS: Sixteen patients had adenoma, and 12 had adenocarcinoma. Early complications occurred in 36% of all patients (hemorrhage, 7; cholangitis, 3; perforation, 2; cholecystitis, 1). The frequency of early complications in Group A was significantly lower than that in Group B (6% vs 75%, odds ratio [OR] 0.022, 95% confidence interval [CI], 0.0020-0.25). Late complications occurred in 18% of the patients (bile duct stone, 3; hemorrhage, 1; pancreatitis, 1). There was no significant difference in the late complication rate between Group A and Group B (19% vs 17%). Local recurrences were found in 14% of the patients, without a significant difference between Group A and Group B (19% vs 8%) during a mean follow-up period. All recurrent tumors were successfully treated with argon plasma coagulation. CONCLUSIONS: The modified technique of EP for ampullary neoplasm contributed to lessening the occurrence of early complications. However, further refinement of this technique is necessary for improving the clinical outcome.

[A case of mucinous cystadenoma of the pancreas resected after a 10-year follow-up].

A 40-year-old woman was hospitalized because of acute pancreatitis. CT showed a monolocular cyst thought to be a pseudocyst. The patient was followed as an outpatient. The size of the cyst decreased 6 years later. Ultrasonography 10 years later demonstrated an enlarged cyst with a cyst-in-cyst formation. A tendency to increase in size and the irregular wall thickening indicated that the cyst was a malignant mucinous cystic neoplasm (MCN) and distal pancreatectomy was performed. The tumor was diagnosed histologically as a mucinous cystadenoma. A case of MCN resected after long-term follow-up is extremely rare. The present case is thought to be important for elucidation of the natural history of MCNs.

Efficacy of propofol sedation for endoscopic submucosal dissection (ESD): assessment with prospective data collection.

OBJECTIVE: The indications for endoscopic treatment in early stage cancer of the digestive tract are expanding with the emergence and technical development of endoscopic submucosal dissection (ESD). ESD requires longer term stable sedation than conventional endoscopic procedures due to the necessity of meticulous control of the devices during the procedure. Propofol has a very short half-life and can be administered continuously, which is advantageous for long-term sedation. Propofol, thus, is likely to be useful for sedation during ESD. METHODS: Fifty consecutive patients who underwent ESD for early gastric cancer with propofol sedation (Group P) and those with midazolam sedation (Group M) were included in this study. Cardiorespiratory suppression rate and the condition of arousal were compared between the groups. A questionnaire survey on the satisfaction of endoscopists, anesthesiologists, endoscopy nurses, and ward nurses with the use of propofol was also carried out. RESULTS: Respiratory suppression was observed in 50% in Group M and in 20% in Group P (p<0.05). Hypotension was seen in 14% and 36% in Groups M and P, respectively (p<0.05). No sedation-related complications were encountered in either of the groups. Arousal rates 1 hour and 3 hours after the procedure were 23% and 60% in group M and 86% and 100% in Group P (p<0.05). As for the questionnaire survey, most respondents, in particular the ward nurses, supported the use of propofol. CONCLUSION: Our data suggest that propofol is safe and useful during ESD as compared with midazolam.

Mediastinal emphysema after esophageal endoscopic submucosal dissection: its prevalence and clinical significance.

AIMS: To assess the prevalence and clinical significance of mediastinal emphysema (ME) after esophageal endoscopic submucosal dissection (ESD). METHODS: A total of 105 patients in whom assessment of ME was prospectively carried out with multi-detector row computed tomography (MDCT) after esophageal ESD were included in this study. ME was graded as follows: Grade-0, no ME; Grade-I, bubbles around the esophagus; Grade-II, ME around the thoracic aorta; Grade-III, ME extending around the heart or beyond the mediastinum into the neck; and Grade-IV, ME with pneumothorax or subcutaneous emphysema. MDCT grading was compared with the finding of conventional chest X-ray images (CXR) and clinical symptoms. RESULTS: CXR revealed the presence of ME in 6.6% of the subjects. On MDCT, ME was recognized in 62.9% (Grade-0, 37.1%; I, 46.7%; II, 10.5%; III, 5.7%; and IV, 0%), most (83.8%) being Grade-I or 0. CXR was able to visualize ME of Grade-II or greater. Exposure of the muscularis propria layer and location of the lesion were significant risk factors for development of ME of Grade-II or greater (P = 0.008 and P = 0.03, respectively). The duration of a fever of 37°C or higher was longer and the serum C-reactive protein level was higher in patients with a higher grade of ME. CONCLUSIONS: MDCT revealed the occurrence of ME in 62.9% of the patients who had undergone esophageal ESD, most of which, however, was clinically silent. Exposure of the muscular layer during ESD and location of the lesion were independent risk factors for the development of ME.

Intraductal ultrasonography in the diagnosis of bile duct stones: when and whom?

BACKGROUND AND AIM: Biliary intraductal ultrasonography (IDUS) is highly sensitive in visualizing bile duct stones (BDS). Indications for IDUS, however, in cases of suspected BDS have not yet been established. The aim of the present study was to elucidate adequate indications for IDUS in cases that undergo endoscopic retrograde cholangiopancreatography (ERCP) due to suspected BDS. METHODS: A total of 213 patients who were suspected of having BDS were included in this retrospective study. The patients were divided into two groups: Group A in which BDS was visualized by ERCP; and Group B in which BDS was demonstrated only by IDUS. Comparison between the groups was carried out. RESULTS: ERCP successfully visualized BDS in 166 patients. Forty-seven patients underwent IDUS, which revealed BDS and biliary sludge in 12 and eight patients, respectively. The diameter of the largest stone was 13 ± 6 mm in Group A and 5 ± 1 mm in Group B (P < 0.001). The sensitivity, specificity, and accuracy of ERCP in the diagnosis of BDS were 93%, 100%, and 94%, respectively. The sensitivity was influenced by the size of BDS: 100% in cases of stones ≥ 8 mm in size, but 74% in those with stones < 8 mm. In cases with stones < 8 mm, the sensitivity was significantly affected by the bile duct diameter (≥ 12 mm vs < 12 mm, P < 0.05). CONCLUSION: When ERCP fails to visualize stones in patients with suspected BDS, IDUS is recommended, especially in those with a bile duct ≥ 12 mm in diameter.