Efficacy Analysis of Suprapapillary versus Transpapillary Self-Expandable Metal Stents According to the Level of Obstruction in Malignant Extrahepatic Biliary Obstruction

Background/Aims@#The use of a self-expandable metal stent (SEMS) is recommended for unresectable malignant biliary obstruction (MBO). Stent-related adverse events might differ according to the position of the stent through the ampulla of Vater (AOV). We retrospectively evaluated SEMS patency and adverse events according to the position of the SEMS. @*Methods@#In total, 280 patients who underwent endoscopic SEMS placement due to malignant distal biliary obstruction were analyzed retrospectively. Suprapapillary and transpapillary SEMS insertions were performed on 51 patients and 229 patients, respectively. @*Results@#Between the suprapapillary group (SPG) and transpapillary group (TPG), the stent patency period was not significantly different (median [95% confidence interval]: 107 days [82.3 to 131.7] vs 120 days [99.3 to 140.7], p=0.559). There was also no significant difference in the rate of adverse events. In subgroup analysis, the stent patency for an MBO located within 2 cm from the AOV was found to be significantly shorter than that for an MBO located more than 2 cm from the AOV in the SPG (64 days [0 to 160.4] vs 127 days [82.0 to 171.9], p<0.001) and TPG (87 days [52.5 to 121.5] vs 130 [97.0 to 162.9], p<0.001). Patients with an MBO located within 2 cm from the AOV in both groups had a higher percentage of duodenal invasion (SPG: 40.0% vs 4.9%, p=0.002; TPG: 28.6% vs 2.9%, p<0.001) than patients with an MBO located more than 2 cm from the AOV. @*Conclusions@#The SPG and TPG showed similar results in terms of stent patency and rate of adverse events. However, patients with an MBO located within 2 cm from the AOV had a higher percentage of duodenal invasion with shorter stent patency than those with an MBO located more than 2 cm from the AOV, regardless of stent position.

Recent Updates on Endoscopic Retrograde Cholangiography-guided Intraductal Radiofrequency Ablation for Malignant Biliary Stricture / 대한소화기학회지

Malignant biliary strictures are caused by pancreatobiliary cancer and other metastatic malignancies. Most of them are unresectable at diagnosis with a dismal prognosis. Various new ablation methods have been introduced. Of them, ERCP-guided intraductal radiofrequency ablation (ID-RFA) appears to be the most promising minimally invasive endoscopic treatment by delivering a high-frequency alternating current to the target tissue, leading to coagulative necrosis. Thus far, many studies have provided evidence that ERCP-guided ID-RFA is a safe, feasible, and effective treatment modality for stent patency and overall survival. Compared to other ablation treatments, ERCP-guided ID-RFA has several advantages, including ease of delivery, controlled application of thermal energy, low cost, and fewer systemic side effects with an acceptable safety profile. Therefore, ERCP-guided ID-RFA can be considered an adjunctive treatment for the palliation of unresectable malignant biliary strictures. On the other hand, the decision of local ablation treatment should be individualized by multidisciplinary team support due to the lack of comparative studies.

Drug-eluting Biliary Stent / 대한췌담도학회지

Biliary drainage is necessary to improve the survival or quality of life of patients with malignant biliary obstruction. In the past, surgery was the primary treatment for biliary drainage, but recently, endoscopic or percutaneous stent implantation has been recognized as the main treatment. Various materials and structures have been devised and developed to increase the patency of the biliary stent. In the development of these stents, drug-eluting biliary stents with an anti-tumoral agent (DES) have emerged to increase the stent patency period by chemically inhibiting tumor growth in the stent through the change of the coating material. The DESs have been proved to be stable through several animal and clinical trials, but their effectiveness has not been demonstrated. We will discuss the development process, problems, and future directions of DES that has been clinically applied.

Novel Insights into the Pathogenesis and Management of the Metabolic Syndrome / 대한소아소화기영양학회지

The metabolic syndrome, by definition, is not a disease but is a clustering of individual metabolic risk factors including abdominal obesity, hyperglycemia, hypertriglyceridemia, hypertension, and low high-density lipoprotein cholesterol levels. These risk factors could dramatically increase the prevalence of type 2 diabetes and cardiovascular disease. The reported prevalence of the metabolic syndrome varies, greatly depending on the definition used, gender, age, socioeconomic status, and the ethnic background of study cohorts. Clinical and epidemiological studies have clearly demonstrated that the metabolic syndrome starts with central obesity. Because the prevalence of obesity has doubly increased worldwide over the past 30 years, the prevalence of the metabolic syndrome has markedly boosted in parallel. Therefore, obesity has been recognized as the leading cause for the metabolic syndrome since it is strongly associated with all metabolic risk factors. High prevalence of the metabolic syndrome is not unique to the USA and Europe and it is also increasing in most Asian countries. Insulin resistance has elucidated most, if not all, of the pathophysiology of the metabolic syndrome because it contributes to hyperglycemia. Furthermore, a major contributor to the development of insulin resistance is an overabundance of circulating fatty acids. Plasma fatty acids are derived mainly from the triglycerides stored in adipose tissues, which are released through the action of the cyclic AMP-dependent enzyme, hormone sensitive lipase. This review summarizes the latest concepts in the definition, pathogenesis, pathophysiology, and diagnosis of the metabolic syndrome, as well as its preventive measures and therapeutic strategies in children and adolescents.

Recent Updates on Diagnosis, Treatment, and Follow-up of Gallbladder Polyps / 대한소화기학회지

A gallbladder (GB) polyp is an elevation of the GB mucosa that protrudes into the GB lumen. GB polyps have an estimated prevalence of 0.3-9.5% and can be divided into neoplastic (true) polyps and nonneoplastic polyps (pseudopolyps). Pseudopolyps are most commonly cholesterol polyps but also include focal adenomyomatosis and inflammatory polyps with no malignant potential. Neoplastic polyps, however, can be benign or malignant. Benign polyps are most commonly adenomas, while malignant polyps are usually adenocarcinoma. Transabdominal ultrasonography is the main radiological modality used for diagnosing and surveilling GB polyps. On the other hand, because it is difficult to diagnose GB polyps before surgery, alternative imaging modalities, such as endoscopic ultrasound, are being further evaluated. The current guidelines recommend cholecystectomy for GB polyps ≥ 10 mm in size as well as suboptimal sized GB polyps (6-9 mm) with other risk factors, including age >50, sessile, and symptoms. The quality of the evidence behind this practice is relatively low. Therefore, this review identifies the current gaps in the available evidence and guidelines and introduces methods that can help make decisions regarding patients who require a cholecystectomy or follow-up.

Magnetic Compression Anastomosis for the Treatment of Post-Transplant Biliary Stricture

A number of different conditions can lead to a bile duct stricture. These strictures are particularly common after biliary operations, including living-donor liver transplantation. Endoscopic and percutaneous methods have high success rates in treating benign biliary strictures. However, these conventional methods are difficult to manage when a guidewire cannot be passed through areas of severe stenosis or complete obstruction. Magnetic compression anastomosis has emerged as an alternative nonsurgical treatment method to avoid the mortality and morbidity risks of reoperation. The feasibility and safety of magnetic compression anastomosis have been reported in several experimental and clinical studies in patients with biliobiliary and bilioenteric strictures. Magnetic compression anastomosis is a minimally traumatic and highly effective procedure, and represents a new paradigm for benign biliary strictures that are difficult to treat with conventional methods.

IgG4-Related Hepatic Inflammatory Pseudotumor Complicated by Actinomycosis during Steroid Therapy

For a 67-year-old man with diabetes mellitus, a 9-cm liver mass was found on CT during the diagnostic work-up for weight loss and fever. Dynamic CT and MRI showed a layered pattern of contrast enhancement suggesting the imaging features of the solid inflammatory mass. After tissue diagnosis of immunoglobulin G4 (IgG4)-related disease by gun needle biopsy, steroid therapy induced partial shrinkage of the mass on the follow-up CT at 4 weeks. On the 5-month follow-up CT with the maintenance of low-dose oral steroid medication, disease progression with invasion to diaphragm brought surgical intervention of right hemihepatectomy considering the possibility of combined malignancy. In the area of diaphragmatic destruction, focal actinomycosis was complicated in the main mass of IgG4-related disease. We are the first to describe a rare case of IgG4-related inflammatory pseudotumor, complicated by actinomycosis, showing an invasive nature that mimicked malignancy during steroid therapy in a diabetic patient.

Methionyl-tRNA Synthetase is a Useful Diagnostic Marker for Lymph Node Metastasis in Non-Small Cell Lung Cancer

PURPOSE: Identification of lymph node (LN) metastasis in non-small cell lung cancer (NSCLC) is critical for disease staging and selection of therapeutic modalities. Sometimes it is not possible to obtain LN core tissue by endobronchial ultrasound-guided transbronchial needle aspirate (EBUS-TBNA), resulting in low diagnostic yield. MATERIALS AND METHODS: In this study, 138 specimens were collected from 108 patients who underwent EBUS-TBNA under the suspicion of LN metastasis of NSCLC. Diagnostic yields of anti-CD45 and anti-methionyl-tRNA synthetase (MRS), immunofluorescent (IF) staining on cytology specimens were compared with those of conventional cytology and positron emission tomography-computed tomography (PET-CT). RESULTS: MRS was strongly expressed in NSCLC cells metastasized to LNs, but weakly expressed in cells at the periphery of the LN germinal center. The majority of cells were CD20 positive, although a few cells were either CD3 or CD14 positive, indicating that CD45 staining is required for discrimination of non-malignant LN constituent cells from NSCLC cells. When the diagnostic efficacy of MRS/CD45 IF staining was evaluated using 138 LN cellular aspirates from 108 patients through EBUS-TBNA, the sensitivity was 76.7% and specificity was 90.8%, whereas those of conventional cytology test were 71.8% and 100.0%, respectively. Combining the results of conventional cytology testing and those of PET-CT showed a sensitivity and specificity of 71.6% and 100%, and the addition of MRS/CD45 dual IF data to this combination increased sensitivity and specificity to 85.1% and 97.8%, respectively. CONCLUSION: MRS/CD45 dual IF staining showed good diagnostic performance and may be a good tool complementing conventional cytology test for determining LN metastasis of NSCLC.

Endoscopic Sphincterotomy, Balloon Stone Extraction, and Basket Stone Extraction / 대한췌담도학회지

Endoscopic sphincterotomy is performed after selective cannulation to remove the gallstone. Endoscopic sphincterotomy can cause complications such as bleeding, perforation and pancreatitis. Various types of endoscopic sphincter incision method and current generators used for incisions have been developed to reduce the incidence of such complications and increase the success rate of the procedure. In addition, guidelines for the direction and extent of endoscopic sphincterotomy and incision technique are established. The method used for the removal of gallstones after the endoscopic sphincterotomy is a method using a balloon and/or a basket. This review introduces the technical methods of endoscopic sphincterotomy and discusses the clinical indications and technical methods for representative methods of effective gallstone removal.

Safety Evaluation of Paclitaxel-Eluting Biliary Metal Stent with Sodium Caprate in Porcine Biliary Tract

BACKGROUND/AIMS: Metallic stents designed to relieve malignant biliary obstruction are susceptible to occlusive tumor ingrowth or overgrowth. In a previous report, we described metallic stents covered with paclitaxel-incorporated membrane (MSCPM-I, II) to prevent occlusion from tumor ingrowth via antitumor effect. This new generation paclitaxel-eluting biliary stent is further endowed with sodium caprate (MSCPM-III) for enhanced drug delivery. The purpose of this study is to examine the safety of its drug delivery system in the porcine biliary tract. METHODS: MSCPM-III (10% [wt/vol] paclitaxel) and covered metal stents (CMSs) were endoscopically inserted in porcine bile ducts in vivo. Histologic biliary changes, levels of paclitaxel released, and various serum analytes (albumin, alkaline phosphate, aspartate transaminase, alanine transaminase, total protein, total bilirubin, and direct bilirubin) were assessed. RESULTS: Based on the intensity of reactive inflammation and fibrosis, changes in porcine biliary epithelium secondary to implanted MSCPM-III were deemed acceptable (i.e., safe). Histologic features in the MSCPM-III and CMS groups did not differ significantly. In a related serum analysis, paclitaxel release from MSCPM-III stents was below the limit of detection for 28 days. Biochemical analyses were also similar for the two groups, and no evidence of hepatic or renal toxicity was found in animals receiving MSCPM-III stents. CONCLUSIONS: In a prototypic porcine trial, this newly devised metal biliary stent incorporating both paclitaxel and sodium caprate appears to be safe in the porcine bile duct.

Clinical Practice Guideline for Common Bile Duct Stones: Diagnosis and Treatment / 대한소화기학회지

Common bile duct (CBD) stone is a biliary disease with an increasing incidence in Korea. Many advances have been made in diagnosis and treatment according to the development of imaging equipment and various devices to diagnose and treat CBD stones. The Korean Society for Pancreatobiliary Association has developed clinical practice guidelines for the diagnosis and treatment of CBD stones to assist clinicians in their management. The guidelines were divided into three parts: evaluation of CBD stones, endoscopic management of CBD stones, and endoscopic management of difficult and recurrent CBD stones. The purpose of this review is to summarize and present the diagnosis and treatment guidelines for CBD stones established in Korea.

Introduction of an Educational Accreditation System for Abdominal Ultrasonography / 대한소화기학회지

Abdominal ultrasonography uses the transmission and reflection of ultrasound waves to observe the internal organs through the abdominal wall and can visualize various abdominal anatomical structures. Abdominal ultrasound examinations are performed by gastroenterologists or other specialists in internal medicine and radiologists trained for this procedure. Thus far, abdominal ultrasonography has not been included in the standard education of gastroenterologists in Korea. On the other hand, abdominal ultrasonography is being used increasingly, making it necessary to establish a training program in Korea. Abdominal ultrasonography was established as an essential part of education for the resident training program in 2017. In addition, an educational accreditation system for the trainers of ultrasonography in the field of internal medicine, including gastroenterology, was developed in 2018. This article describes the development process of the educational accreditation system for trainers of ultrasonography.

Anastomotic stricture after liver transplantation: It is not Achilles' heel anymore!

Biliary-tract complications, such as biliary strictures, anastomotic leaks, choledocholithiasis, and biliary casts, can occur after liver transplantation (LT). Of these complications, biliary strictures are regarded as an Achilles' heel. Recently, treatment of anastomotic biliary stricture (ABS) has transitioned from conventional surgical revision to a nonsurgical treatment modality. Endoscopic serial balloon dilatation and/or multiple plastic stent replacements are highly effective and are now regarded as the first-line treatments. However, if the patient has undergone anastomosis by means of a hepaticojejunostomy, percutaneous treatment is performed. With recent technological advances and the rendezvous method, the clinical success rates of endoscopic and percutaneous ABS treatments have increased, but these methods fail in some patients who have total obstruction of anastomotic stricture. For these patients, magnetic compression anastomosis (MCA) has been suggested as an alternative method. Animal and human studies have demonstrated the safety and efficacy of MCA, and advancements in these nonsurgical methods have increased the clinical success rate of ABS. This review focuses on ABSs that develop after LT and discusses the clinical results of various nonsurgical methods and future directions.

The Usefulness of Minimally Invasive Plate Osteosynthesis to Manage Comminuted Mid-Clavicle Fracture: A Comparison with Conventional Open Plating / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to compare the clinical and radiological outcomes of minimally invasive plate osteosynthesis (MIPO) with those of conventional open plating (COP) for treating comminuted mid-clavicular fractures and to evaluate the usefulness of MIPO. MATERIALS AND METHODS: Thirty-nine patients who underwent surgical treatment for mid-clavicular comminuted fractures were analyzed retrospectively. Nineteen patients were treated with MIPO and twenty patients with COP. Radiological evaluation included time to union, fracture healing, and clavicular length difference measured as the proportional length difference with the unaffected side. Clinical assessment was performed using the simple shoulder test score, American Shoulder and Elbow Surgeons score, and quick disability of the arm, shoulder and hand score. Moreover, the mean operation and radiation times, as well as exposure were compared. RESULTS: All clavicles achieved bone union. The mean time to union was 12.1 weeks in the MIPO group, and 14.6 weeks in the COP group (p=0.587). There was no significant difference between the two groups regarding the functional and radiological outcomes at 2-year follow-up. A significantly shorter operation time was observed in the MIPO group than in the COP group (75.8 min vs. 106.9 min, p=0.002). More radiation time and exposure were identified in the MIPO group (52.8 s vs. 37.1 s, p=0.002; 209.4 mGy vs. 43.1 mGy, p=0.005). CONCLUSION: Both COP and MIPO were shown to be effective treatment options for mid-clavicular comminuted fractures. MIPO may be a better alternative to COP due to shorter operation time and no need for a bone graft, although the functional and radiological outcomes were not significantly different. However, all surgeons should pay close attention to minimize radiation hazard.

Efficacy of a Multiplex Paclitaxel Emission Stent Using a Pluronic® Mixture Membrane versus a Covered Metal Stent in Malignant Biliary Obstruction: A Prospective Randomized Comparative Study

BACKGROUND/AIMS: A drug-eluting stent for unresectable malignant biliary obstruction was developed to increase stent patency by preventing tumor ingrowth. The safety and efficacy of a new generation of metallic stents covered with a paclitaxel-incorporated membrane using a Pluronic® mixture (MSCPM-II) were compared prospectively with those of covered metal stents (CMSs) in patients with malignant biliary obstructions. METHODS: This study was initially designed as a prospective randomized trial but was closed early because of a high incidence of early occlusion. Therefore, the data were analyzed using the intent-to-treat method. A total of 72 patients with unresectable distal malignant biliary obstructions were prospectively enrolled. RESULTS: The two groups did not differ significantly in basic characteristics and mean follow-up period (MSCPM-II 194 days vs CMS 277 days, p=0.063). Stent occlusion occurred in 14 patients (35%) who received MSCPM-II and in seven patients (21.9%) who received CMSs. Stent patency and survival time did not significantly differ between the two groups (p=0.355 and p=0.570). The complications were mild and resolved by conservative management in both groups. CONCLUSIONS: There were no significant differences in stent patency or patient survival in MSCPM-II and CMS patients with malignant biliary obstructions.

Pancreatic perforation caused by the Soehendra® retrieval device in a patient with chronic pancreatitis

SUMMARY OF EVENT: An endoscopic retrograde pancreatic duct (ERPD) stent was inserted in a male patient with chronic pancreatitis via endoscopic retrograde cholangiopancreatography (ERCP) to relieve chronic epigastric pain. After the procedure, an abdominal computed tomography scan showed localized peritonitis with a dislocated ERPD stent. The patient underwent an emergency operation, which revealed that the peritonitis was caused by perforation of the pancreatic parenchyma by the ERPD stent. TEACHING POINT: A hydrophilic guide wire can puncture the pancreas during ERPD stent insertion. Therefore, it is necessary to ensure that the guide wire reaches the main pancreatic duct, especially in patients with chronic pancreatitis.

Prognostic Factors and Scoring Model for Survival in Metastatic Biliary Tract Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Metastatic biliary tract cancer (mBTC) has a dismal prognosis. In this study, an independent dataset of patients with mBTC was used to implement and validate a routine clinico-laboratory parameter-based scoring model for risk group identification. MATERIALS AND METHODS: From September 2006 to February 2015, 482 patients with mBTC were assigned randomly (ratio, 7:3) into investigational (n=340) and validation datasets (n=142). The continuous variables were dichotomized using a normal range or the best cutoff values determined using the Contal and O'Quigley statistical methods. Following a Cox’s proportional hazard model, the scoring model was derived by summing the rounded chi-square scores for the factors identified by multivariate analysis. RESULTS: The performance status (Eastern Cooperative Oncology Group 3-4), hypoalbuminemia (< 3.4 mg/dL), carcinoembryonic antigen (≥ 9 ng/mL), neutrophil-to-lymphocyte ratio (≥ 3.0), and carbohydrate antigen 19-9 (≥ 120 U/mL) were identified as independent prognosticators (Harrell’s C index, 0.682; integrated area under the curve, 0.653). Survival was clearly correlated with the risk groups (low, intermediate, and high, 14.0, 7.3, and 2.3 months, respectively; p < 0.001). The prognosis was also discriminative in the validation data set (median survival, 16.7, 7.5, and 1.9 months, respectively; p < 0.001). Chemotherapy did not offer any survival benefits for high-risk patients. CONCLUSION: These proposed prognostic criteria for mBTC can facilitate accurate patient risk stratification and treatment-related decision-making.

Launching the Hospitalist in Korea / 대한내과학회지

No abstract available.

Prognostic Scoring Index for Patients with Metastatic Pancreatic Adenocarcinoma / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study focused on implementation of a prognostic scoring index based on clinico-laboratory parameters measured routinely on admission in metastatic pancreatic cancer patients. MATERIALS AND METHODS: Records from 403 patients of metastatic disease were analyzed retrospectively. Continuous variables were dichotomized according to the normal range or the best cut-off values statistically determined by Contal and O’Quigley method, and then analyzed in association with prognosis—overall survival (OS), using Cox's proportional hazard model. Scores were calculated by summing the rounded chi-square scores for the factors that emerged in the multivariate analysis. RESULTS: Performance status, hemoglobin, leucocyte count, neutrophil-lymphocyte ratio, and carcinoembryonic antigen were independent factors for OS. When patients were divided into three risk groups according to these factors, median survival was 11.7, 6.2, and 1.3 months for the low, intermediate, and high-risk groups, respectively (p < 0.001). Palliative chemotherapy has a significant survival benefit for low and intermediate-risk patients (median OS; 12.5 months vs. 5.9 months, p < 0.001 and 8.0 months vs. 2.0 months, p < 0.001, respectively). CONCLUSION: We advocate the use of a multivariable approach with continuous variables for prognostic modeling. Our index is helpful in accurate patient risk stratification and may aid in treatment selection.

Update on Pancreatobiliary Stents: Stent Placement in Advanced Hilar Tumors

Palliative drainage is the main treatment option for inoperable hilar cholangiocarcinoma to improve symptoms, which include cholangitis, pruritus, high-grade jaundice, and abdominal pain. Although there is no consensus on the optimal method for biliary drainage due to the paucity of large-scale randomized control studies, several important aspects of any optimal method have been studied. In this review article, we discuss the liver volume to be drained, stent type, techniques to insert self-expanding metal stents, and approaches for proper and effective biliary drainage based on previous studies and personal experience.