A Case of High-Dose-Rate Brachytherapy Under Endoscopic Retrograde Cholangiopancreatography (ERCP) for Intraductal Papillary Neoplasm of the Bile Duct.

Intraductal papillary neoplasm of the bile duct (IPNB) represents a relatively nascent pathological entity, recognized as a precancerous condition within the spectrum of cholangiocarcinoma. Surgical intervention is advocated for all patients with IPNB due to their susceptibility toward obstructive jaundice, cholangitis, and the heightened likelihood of malignant transformation. Nonetheless, the efficacy of radiation therapy for IPNB cases that are either inoperable or refractory remains inadequately substantiated. Herein, we present a case study of an IPNB patient who declined surgery, and a commendable local control was accomplished solely through the implementation of brachytherapy utilizing Ir-192. A septuagenarian Japanese man presented at our medical institution with the chief complaint of jaundice and was subsequently diagnosed with IPNB. The IPNB lesion extensively spanned from the lower intrapancreatic bile duct to the right (extending to B5/B8) and left bile ducts (up to just before B4). The patient underwent weekly endoscopic retrograde cholangiopancreatography (ERCP) sessions. The prescribed treatment regimen encompassed 36 Gy/6 Fr high-dose-rate brachytherapy (HDR-BT) administered once per week during ERCP, with each treatment session adhering to a timeframe not exceeding two hours. Two months following the initiation of treatment, a biliary endoscopy demonstrated complete resolution of the tumor lesion and amelioration of jaundice. The only observed acute adverse event was grade 2 hepatic dysfunctions. To the best of our knowledge, this represents the first documented instance of HDR-BT employed in IPNB management, suggesting its potential as a viable alternative for inoperable or refractory IPNB cases.

Which is a real valuable screening tool for lung cancer and measure thoracic diseases, chest radiography or low-dose computed tomography?: A review on the current status of Japan and other countries.

Chest radiography (CR) has been used as a screening tool for lung cancer and the use of low-dose computed tomography (LDCT) is not recommended in Japan. We need to reconsider whether CR really contributes to the early detection of lung cancer. In addition, we have not well discussed about other major thoracic disease detection by CR and LDCT compared with lung cancer despite of its high frequency. We review the usefulness of CR and LDCT as veridical screening tools for lung cancer and other thoracic diseases. In the case of lung cancer, many studies showed that LDCT has capability of early detection and improving outcomes compared with CR. Recent large randomized trial also supports former results. In the case of chronic obstructive pulmonary disease (COPD), LDCT contributes to early detection and leads to the implementation of smoking cessation treatments. In the case of pulmonary infections, LDCT can reveal tiny inflammatory changes that are not observed on CR, though many of these cases improve spontaneously. Therefore, LDCT screening for pulmonary infections may be less useful. CR screening is more suitable for the detection of pulmonary infections. In the case of cardiovascular disease (CVD), CR may be a better screening tool for detecting cardiomegaly, whereas LDCT may be a more useful tool for detecting vascular changes. Therefore, the current status of thoracic disease screening is that LDCT may be a better screening tool for detecting lung cancer, COPD, and vascular changes. CR may be a suitable screening tool for pulmonary infections and cardiomegaly.

Multicenter comparative study on the usefulness of the optimal electrosurgical unit setting in endoscopic papillectomy for ampullary neoplasms (with video).

BACKGROUND: Endoscopic papillectomy (EP) is less invasive than surgery but procedure-related adverse events (AEs) still frequently occur. This study compared the benefits of EP using a new optimal endoCUT setting on the VIO (Erbe) electrosurgical unit (VIO-EP) with those using the conventional electrosurgical unit setting (ICC-EP, Erbe). METHODS: This multicenter, retrospective, comparative cohort study included 57 patients who underwent VIO-EP and 91 who underwent ICC-EP. The primary outcome was occurrence of EP-related AEs. Secondary outcomes were pathological findings (the resection margins, the R0 resection, and residual lesions). RESULTS: Pancreatitis tended to be less common in the VIO-EP group (5.3% vs. 9.9%, p = .248). Evaluation of computed tomography images showed that pancreatitis was confined to the pancreatic head in 77.8% of cases in the ICC-EP group and in 33.3% of those in the VIO-EP group. After exclusion of cases of delayed bleeding, pancreatitis tended to be less common in the VIO-EP group; this finding was not statistically significant (2.3% vs. 8.2%, p = .184). In pathological findings, residual lesions were significantly less common in the VIO-EP group. CONCLUSIONS: The risks of pancreatitis and residual lesions after EP may be lower when the VIO electrosurgical unit is used with the optimal setting.

Severe induction of aberrant DNA methylation by nodular gastritis in adults.

BACKGROUND: Nodular gastritis (NG) is characterized by marked antral lymphoid follicle formation, and is a strong risk factor for diffuse-type gastric cancer in adults. However, it is unknown whether aberrant DNA methylation, which is induced by atrophic gastritis (AG) and is a risk for gastric cancer, is induced by NG. Here, we analyzed methylation induction by NG. METHODS: Gastric mucosal samples were obtained from non-cancerous antral tissues of 16 NG and 20 AG patients with gastric cancer and 5 NG and 6 AG patients without, all age- and gender-matched. Genome-wide methylation analysis and expression analysis were conducted by a BeadChip array and RNA-sequencing, respectively. RESULTS: Clustering analysis of non-cancerous antral tissues of NG and AG patients with gastric cancer was conducted using methylation levels of 585 promoter CpG islands (CGIs) of methylation-resistant genes, and a large fraction of NG samples formed a cluster with strong methylation induction. Promoter CGIs of CDH1 and DAPK1 tumor-suppressor genes were more methylated in NG than in AG. Notably, methylation levels of these genes were also higher in the antrum of NG patients without cancer. Genes related to lymphoid follicle formation, such as CXCL13/CXCR5 and CXCL12/CXCR4, had higher expression in NG, and genes involved in DNA demethylation TET2 and IDH1, had only half the expression in NG. CONCLUSIONS: Severe aberrant methylation, involving multiple tumor-suppressor genes, was induced in the gastric antrum and body of patients with NG, in accordance with their high gastric cancer risk.

Identifying predictors for comorbidities related mortality versus pancreatic cancer related mortality in patients with intraductal papillary mucinous neoplasm.

BACKGROUNDS: Few data are available for surveillance decisions focusing on factors related to mortality, as the primary outcome, in intraductal papillary mucinous neoplasm (IPMN) patients. AIMS: We aimed to identify imaging features and patient backgrounds associated with mortality risks by comparing pancreatic cancer (PC) and comorbidities. METHODS: We retrospectively conducted a multicenter long-term follow-up of 1864 IPMN patients. Competing risk analysis was performed for PC- and comorbidity-related mortality. RESULTS: During the median follow-up period of 5.5 years, 14.0% (261/1864) of patients died. Main pancreatic duct ≥5 mm and mural nodules were significantly related to all-cause and PC-related mortality, whereas cyst ≥30 mm did not relate. In 1730 patients without high-risk imaging features, 48 and 180 patients died of PC and comorbidity. In the derivation cohort, a prediction model for comorbidity-related mortality was created, comprising age, cancer history, diabetes mellitus complications, chronic heart failure, stroke, paralysis, peripheral artery disease, liver cirrhosis, and collagen disease in multivariate analysis. If a patient had a 5 score, 5- and 10-year comorbidity-related mortality is estimated at 18.9% and 50.2%, respectively, more than 7 times higher than PC-related mortality. The model score was also significantly associated with comorbidity-related mortality in a validation cohort. CONCLUSIONS: This study demonstrates main pancreatic duct dilation and mural nodules indicate risk of PC-related mortality, identifying patients who need periodic examination. A comorbidity-related mortality prediction model based on the patient's age and comorbidities can stratify patients who do not require regular tests, especially beyond 5 years, among IPMN patients without high-risk features. CLINICAL TRIAL REGISTRATION: T2022-0046.

Endoscopic ultrasound-guided biopsy using a three-prong asymmetry tip needle for pancreatic tumors and peridigestive tract lesions: Retrospective single-center study.

BACKGROUND: Endoscopic ultrasound-guided tissue acquisition is vital for diagnosing pancreatic and peridigestive tract lesions. A new three-prong asymmetry tip needle has been developed for this procedure. In this study, we retrospectively assessed the diagnostic ability, tissue collection volume, and procedural adverse events of the three-prong asymmetry tip needle for solid pancreatic, subepithelial, and other organ lesions. METHODS: We analyzed the data of 58 consecutive patients who underwent endoscopic ultrasound-guided tissue acquisition using a three-prong asymmetry tip needle between August 2022 and April 2023 at a single care center. RESULTS: The tissue collection rate was 91.4% with 89.7% accuracy, 89.3% sensitivity, 100% specificity, 100% positive predictive value, and 25% negative predictive value. No significant differences in collection rates or diagnostic performance were observed based on the target organ, puncture route, or lesion size. Using our original assessment method, the average histological core tissue score was 3.1 ± 0.8, whereas the blood contamination volume was 2.5 ± 0.8. Only one of 58 patients (1.7%) developed a pancreatic fistula of moderate severity as an adverse event. CONCLUSIONS: The three-prong asymmetry tip needle demonstrated good diagnostic capability and adequate sample volume with safety for pancreatic, subepithelial, and other organ lesions.

Endoscopic ultrasonography-guided gastroenterostomy versus uncovered duodenal metal stenting for unresectable malignant gastric outlet obstruction (DRA-GOO): a multicentre randomised controlled trial.

BACKGROUND: Endoscopic ultrasonography-guided gastroenterostomy (EUS-GE) is a novel endoscopic method to palliate malignant gastric outlet obstruction. We aimed to assess whether the use of EUS-GE with a double balloon occluder for malignant gastric outlet obstruction could reduce the need for reintervention within 6 months compared with conventional duodenal stenting. METHODS: The was an international, multicentre, randomised, controlled trial conducted at seven sites in Hong Kong, Belgium, Brazil, India, Italy, and Spain. Consecutive patients (aged ≥18 years) with malignant gastric outlet obstruction due to unresectable primary gastroduodenal or pancreatobiliary malignancies, a gastric outlet obstruction score (GOOS) of 0 (indicating an inability in intake food or liquids orally), and an Eastern Cooperative Oncology Group performance status score of 3 or lower were included and randomly allocated (1:1) to receive either EUS-GE or duodenal stenting. The primary outcome was the 6-month reintervention rate, defined as the percentage of patients requiring additional endoscopic intervention due to stent dysfunction (ie, restenosis of the stent due to tumour ingrowth, tumour overgrowth, or food residue; stent migration; or stent fracture) within 6 months, analysed in the intention-to-treat population. Prespecified secondary outcomes were technical success (successful placement of a stent), clinical success (1-point improvement in gastric outlet obstruction score [GOOS] within 3 days), adverse events within 30 days, death within 30 days, duration of stent patency, GOOS at 1 month, and quality-of-life scores. This study is registered with ClinicalTrials.gov (NCT03823690) and is completed. FINDINGS: Between Dec 1, 2020, and Feb 28, 2022, 185 patients were screened and 97 (46 men and 51 women) were recruited and randomly allocated (48 to the EUS-GE group and 49 to the duodenal stent group). Mean age was 69·5 years (SD 12·6) in the EUS-GE group and 64·8 years (13·0) in the duodenal stent group. All randomly allocated patients completed follow-up and were analysed. Reintervention within 6 months was required in two (4%) patients in the EUS-GE group and 14 (29%) in the duodenal stent group [p=0·0020; risk ratio 0·15 [95% CI 0·04-0·61]). Stent patency was longer in the EUS-GE group (median not reached in either group; HR 0·13 [95% CI 0·08-0·22], log-rank p<0·0001). 1-month GOOS was significantly better in the EUS-GE group (mean 2·41 [SD 0·7]) than the duodenal stent group (1·91 [0·9], p=0·012). There were no statistically significant differences between the EUS-GE and duodenal stent groups in death within 30 days (ten [21%] vs six [12%] patients, respectively, p=0·286), technical success, clinical success, or quality-of-life scores at 1 month. Adverse events occurred 11 (23%) patients in the EUS-GE group and 12 (24%) in the duodenal stent group within 30 days (p=1·00); three cases of pneumonia (two in the EUS-GE group and one in the duodenal stent group) were considered to be procedure related. INTERPRETATION: In patients with malignant gastric outlet obstruction, EUS-GE can reduce the frequency of reintervention, improve stent patency, and result in better patient-reported eating habits compared with duodenal stenting, and the procedure should be used preferentially over duodenal stenting when expertise and required devices are available. FUNDING: Research Grants Council (Hong Kong Special Administrative Region, China) and Sociedad Española de Endoscopia Digestiva.

Is preoperative pancreatic juice cytology useful for determining therapeutic strategies for patients with intraductal papillary mucinous neoplasm of the pancreas?

BACKGROUND: We compared the results of preoperative pancreatic juice cytology (PJC) and final pathological diagnosis after resection in patients who underwent resection of intraductal papillary mucinous neoplasm (IPMN) of the pancreas to determine whether preoperative PJC can help determine therapeutic strategies. METHODS: Of 1130 patients who underwent surgical resection IPMN at 11 Japanese tertiary institutions, the study included 852 patients who underwent preoperative PJC guided by endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: The accuracy of preoperative PJC for differentiation between cancerous and noncancerous lesions were 55% for IPMN overall; 59% for the branch duct type; 49% for the main pancreatic duct type; 53% for the mixed type, respectively. On classifying IPMN according to the diameters of the mural nodule (MN) and main pancreatic duct (MPD), the corresponding values for diagnostic performance were 40% for type 1 (MN ≥5 mm and MPD ≥ 10 mm); 46% for type 2 (MN ≥5 mm and MPD < 10 mm); 61% for type 3 (MN < 5 mm and MPD ≥ 10 mm); 72% for type 4 (MN < 5 mm and MPD < 10 mm), respectively. CONCLUSIONS: PJC in IPMN is not a recommended examination because of its low overall sensitivity and no significant difference in diagnostic performance by type, location, or subclassification. Although the sensitivity is low, the positive predictive value is high, so we suggest that pancreatic juice cytology be performed only in cases where the patient is not sure about surgery.

Potential versatile uses of a novel ultra-thin peroral cholangioscope.

Tonozuka and colleagues report the usefulness of a newly developed ultra-thin mother-baby type peroral cholangioscope with a tip external diameter of 2.3 mm for a case of biliary stricture in which conventional peroral cholangioscope insertion was challenging. The novel scope allows simple and low-cost peroral cholangioscopy, making it highly versatile.

Early and late effects of endoscopic interventions in patients with malignant afferent loop syndrome: A single-center experience and literature review.

BACKGROUND/PURPOSE: Afferent loop syndrome (ALS) is a rare adverse event after gastrointestinal surgery requiring appropriate early decompression treatment. Several endoscopic interventions have been attempted for treatment, including endoscopic enteral metal stent placement (EMSP), endoscopic ultrasound (EUS)-guided entero-enterostomy (EUS-EE), and EUS-guided hepaticogastrostomy (EUS-HGS). However, there are limited data on outcomes, including duration of stent patency. In this study, we evaluated the usefulness of each endoscopic intervention for malignant ALS. METHODS: We retrospectively investigated nine patients with malignant ALS who underwent EMSP, EUS-EE, or EUS-HGS. Information on technical success, clinical efficacy, adverse events, stent dysfunction, and overall survival was collected and analyzed. RESULTS: The most common symptoms were abdominal pain and cholangitis. ALS was treated by EMSP in three patients, EUS-EE in three patients, and EUS-HGS in three patients. Stent placement was successful and clinically effective in all patients with no adverse events. During follow-up, stent dysfunction occurred in two patients treated by EUS-HGS. Eight patients died of primary disease during a median follow-up of 157 days. CONCLUSIONS: Each of the available endoscopic interventions for malignant ALS can be expected to produce similar outcomes, including duration of stent patency. The choice of endoscopic intervention should be made based on the characteristics of each treatment.

Deep learning approach for discrimination of liver lesions using nine time-phase images of contrast-enhanced ultrasound.

PURPOSE: Contrast-enhanced ultrasound (CEUS) shows different enhancement patterns depending on the time after administration of the contrast agent. The aim of this study was to evaluate the diagnostic performance of liver nodule characterization using our proposed deep learning model with input of nine CEUS images. METHODS: A total of 181 liver lesions (48 benign, 78 hepatocellular carcinoma (HCC), and 55 non-HCC malignant) were included in this prospective study. CEUS were performed using the contrast agent Sonazoid, and in addition to B-mode images before injection, image clips were stored every minute up to 10 min. A deep learning model was developed by arranging three ResNet50 transfer learning models in parallel. This proposed model allowed inputting up to nine datasets of different phases of CEUS and performing image augmentation of nine images synchronously. Using the results, the correct prediction rate, sensitivity, and specificity between "benign" and "malignant" cases were analyzed for each combination of the time phase. These accuracy values were also compared with the washout score judged by a human. RESULTS: The proposed model showed performance superior to the referential standard model when the dataset from B-mode to the 10-min images were used (sensitivity: 93.2%, specificity: 65.3%, average correct answer rate: 60.1%). It also maintained 90.2% sensitivity and 61.2% specificity even when the dataset was limited to 2 min after injection, and this accuracy was equivalent to or better than human scoring by experts. CONCLUSION: Our proposed model has the potential to identify tumor types earlier than the Kupffer phase, but at the same time, machine learning confirmed that Kupffer-phase Sonazoid images contain essential information for the classification of liver nodules.

Does Congenital Biliary Dilatation Todani Type II (Diverticular Type) Really Exist?

AIM OF THE STUDY: The aim of the study is to clarify the clinicopathological and biliary morphological characteristics in reported cases of diverticular congenital biliary dilatation (CBD). METHOD: Using PubMed and the Japan Medical Abstracts Society, articles on possible diverticular CBD were extracted and the clinical pictures examined. We also sought evidence for definitions of diverticular CBD and the associated condition of pancreaticobiliary maljunction (PBM) using the original articles by Alonso-Lej and Todani. The characteristic biliary morphologies of cases with images were also investigated. RESULTS: Analyses of 211 possible cases superficially demonstrated multiple diverticula in 12 (12%) and single diverticulum in 89 (88%), with diverticula located in the upper (n = 38, 38%), middle (n = 32, 32%), or lower (n = 26, 26%) biliary tract in and presence of intra-diverticular stones, PBM, and biliary carcinoma in 23% (n = 18), 39% (n = 25), and 11% (n = 14), respectively. However, evidence defining diverticular CBD or justifying the lack of associated PBM was not demonstrated even in the original articles. Scrutiny of the biliary anatomy in 59 cases with images showed incorrect inclusions of types I or IV-A with an irregular biliary duct wall or dilated cystic duct, periampullary choledochal diverticula, or even solitary biliary cysts. Authentic diverticular CBD, representing the diverticulum connected to the middle of the common bile duct via a thin, patent stalk was seen in only 6 cases. CONCLUSION: Real diverticular CBD appears extremely rare. The lack of an objective definition allows wide interpretations of clinical pictures, creating inconsistencies in the diagnosis and treatment of CBD and raising questions regarding the utility of conventional classifications. LEVEL OF EVIDENCE: Level III.

Long-term outcomes after EUS-guided antegrade intervention for benign bilioenteric anastomotic stricture.

BACKGROUND AND AIMS: Bilioenteric anastomotic stricture (BES) is a well-known adverse event after bilioenterostomy. Recently, EUS-guided antegrade intervention (EUS-AI) has been developed for cases that are difficult to treat by balloon enteroscopy-assisted ERCP. However, no data are available on the long-term outcomes after EUS-AI. The main goal of the present study was to clarify the long-term outcomes of EUS-AI in such patients. METHODS: Between November 2013 and November 2021, 34 patients who were followed for more than 1 year after EUS-AI for BES were identified. The primary endpoint was the rate of stricture resolution. Secondary endpoints were factors associated with stricture resolution, rate of BES recurrence, rate of conversion to surgery, and rate of hepatic fibrosis progression during follow-up. RESULTS: The median follow-up period was 56.7 months. Stricture resolution was achieved in 17 of 34 patients (50%). A multivariate analysis confirmed that the presence of bile duct stones (odds ratio, 9.473; 95% confidence interval, 1.66-53.98; P = .01) was significantly associated with stricture resolution. The stricture recurrence rate was 33%, and the median time from stent removal to recurrence was 31.2 months. Four patients underwent surgery because of recurrent cholangitis. During the median follow-up period of 56.7 months, 25% progressed to hepatic fibrosis based on the Fibrosis-4 index grade. Interestingly, patients without cholangitis during follow-up did not show progression of hepatic fibrosis. CONCLUSIONS: EUS-AI has achieved acceptable long-term clinical outcomes. EUS-AI can be a viable alternative treatment of choice before surgical treatment in patients who are difficult to treat by conventional approaches.

Preoperative endoscopic ultrasound-guided biliary drainage for primary drainage in obstructive jaundice.

INTRODUCTION: Endoscopic transpapillary approach by endoscopic retrograde cholangiopancreatography (ERCP) is the established technique for preoperative biliary drainage (PBD). Recently, endoscopic ultrasound-guided biliary drainage (EUS-BD) has been reported to be a useful alternative technique after ERCP fail. However, the optimal strategy remain controversial. AREA COVERED: This review summarizes the literature on EUS-BD techniques for PBD with a literature search using PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials database between 2000 and 2023 using keywords for 'preoperative biliary drainage' and all types of EUS-BD techniques. EXPERT OPINION: As there is no consensus on the optimal EUS-BD technique for PBD, selection of the EUS-BD approach depends on the patient's condition, the biliary obstruction site, the anastomosis after surgical intervention, and the preference of the endoscopist. However, we consider that EUS-HGS using a dedicated plastic stent may have some advantages in the adverse impact of surgical procedure because the location where the fistula is created by EUS-HGS is away from the site of the surgical procedure. Although there remain many issues that require further investigation, EUS-BD can be a feasible and safe alternative method of PBD for malignant biliary obstruction after ERCP fail.

Endoscopic retrieval of a proximally migrated fully covered self-expandable metal stent using biopsy forceps with a guiding sheath cannula.

Transpapillary endoscopic biliary drainage is the gold standard for resolving malignant biliary obstruction. Stent migration occasionally occurs and is troublesome to retrieve. Yamamoto and colleagues report with accompanying video on the successful retrieval of a proximally migrated stent using biopsy forceps through a guiding sheath cannula.

A fatal case of massive hemobilia caused by invasive pancreatic cancer with median arcuate ligament syndrome: A case report.

INTRODUCTION: In median arcuate ligament syndrome (MALS), the celiac artery is compressed, causing an arcade to develop in the pancreatic head, leading to ischemic symptoms and aneurysms. PATIENT CONCERNS: The patient was diagnosed with borderline resectable pancreatic cancer (PC) and MALS. Endoscopic biliary drainage with a covered metal stent (CMS) was performed for the obstructive jaundice. After the jaundice improved, a modified FOLFIRINOX regimen was initiated. Several days later, cardiopulmonary arrest occurred after hematemesis occurred. Cardiopulmonary resuscitation was performed, his blood pressure stabilized, and emergent upper endoscopy was performed. The CMS was dislodged and active bleeding was observed in the papillae. The CMS was replaced, and temporary hemostasis was achieved. Contrast-enhanced computed tomography revealed a diagnosis of extravasation from the posterior superior pancreaticoduodenal artery (PSPDA) into the biliary tract. Transcatheter arterial embolization was performed. However, the patient was subsequently diagnosed with hypoxic encephalopathy and died on day 14 of hospitalization. DIAGNOSIS: Biliary hemorrhage due to invasion of pancreatic cancer from the PSPDA associated with MALS. INTERVENTION: None. OUTCOMES: Biliary hemorrhage from the PSPDA was fatal in the patient with invasive PC with MALS. LESSONS: Since MALS associated with PC is not a rare disease, the purpose of this study was to keep in mind the possibility of fatal biliary hemorrhage.

Factors associated with long-term efficacy of lubiprostone for chronic constipation.

The prevalence of chronic constipation in Japan is increasing, and is presently almost 1 in 5 people. Because constipation is common, especially in older patients, to avoid adverse events and polypharmacy, simple treatments at low doses are generally desired. Although the chloride channel activator lubiprostone is candidate drug that may solve these problems, factors associated with the long-term efficacy of lubiprostone monotherapy for chronic constipation in treatment-naive patients remain unclear. We here retrospectively investigated the clinical characteristics and factors of patients who achieved long-term constipation improvement with lubiprostone monotherapy. Seventy-four patients with chronic constipation treated with lubiprostone monotherapy (24 or 48 µg/day) from January 2017 to August 2018 were reviewed. Patient characteristics and clinical time-courses were compared between those who sustained improvement for 6 months, and those who became refractory to treatment. In 54 patients (76.1%), constipation improved by lubiprostone administration for 6 months. On multivariate analysis, a significant clinical factor associated with sustained improvement was a starting lubiprostone dose of 24 µg/day (odds ratio: 5.791; 95% confidence interval: 1.032-32.498; p = 0.046). A starting lubiprostone dose of 24 µg/day has efficacy to improve chronic constipation and to prevent adverse events of nausea and diarrhea in Japanese patients.