Diode Laser—Can It Replace the Electrical Current Used in Endoscopic Submucosal Dissection? (with Video)

Background/Aims@#A new medical fiber-guided diode laser system (FDLS) is expected to offer high-precision cutting with simultaneous hemostasis. Thus, this study aimed to evaluate the feasibility of using the 1,940-nm FDLS to perform endoscopic submucosal dissection (ESD) in the gastrointestinal tract of an animal model. @*Methods@#In this prospective animal pilot study, gastric and colorectal ESD using the FDLS was performed in ex vivo and in vivo porcine models. The completeness of en bloc resection, the procedure time, intraprocedural bleeding, histological injuries to the muscularis propria (MP) layer, and perforation were assessed. @*Results@#The en bloc resection and perforation rates in the ex vivo study were 100% (10/10) and 10% (1/10), respectively; those in the in vivo study were 100% (4/4) and 0% for gastric ESD and 100% (4/4) and 25% (1/4) for rectal ESD, respectively. Deep MP layer injuries tended to occur more frequently in the rectal than in the gastric ESD cases, and no intraprocedural bleeding occurred in either group. @*Conclusions@#The 1,940-nm FDLS was capable of yielding high en bloc resection rates without intraprocedural bleeding during gastric and colorectal ESD in animal models.

Diode Laser—Can It Replace the Electrical Current Used in Endoscopic Submucosal Dissection? (with Video)

Background/Aims@#A new medical fiber-guided diode laser system (FDLS) is expected to offer high-precision cutting with simultaneous hemostasis. Thus, this study aimed to evaluate the feasibility of using the 1,940-nm FDLS to perform endoscopic submucosal dissection (ESD) in the gastrointestinal tract of an animal model. @*Methods@#In this prospective animal pilot study, gastric and colorectal ESD using the FDLS was performed in ex vivo and in vivo porcine models. The completeness of en bloc resection, the procedure time, intraprocedural bleeding, histological injuries to the muscularis propria (MP) layer, and perforation were assessed. @*Results@#The en bloc resection and perforation rates in the ex vivo study were 100% (10/10) and 10% (1/10), respectively; those in the in vivo study were 100% (4/4) and 0% for gastric ESD and 100% (4/4) and 25% (1/4) for rectal ESD, respectively. Deep MP layer injuries tended to occur more frequently in the rectal than in the gastric ESD cases, and no intraprocedural bleeding occurred in either group. @*Conclusions@#The 1,940-nm FDLS was capable of yielding high en bloc resection rates without intraprocedural bleeding during gastric and colorectal ESD in animal models.

Comparison of Effectiveness between Abdominal Vibration Stimulation and Walking Exercise for Bowel Cleansing before Therapeutic Colonoscopy

Background/Aims@#Adequate bowel preparation is important for successful colonoscopy. We aimed to evaluate the clinical feasibility and effectiveness of abdominal vibration stimulation in bowel preparation before therapeutic colonoscopy. @*Methods@#A single center, prospective, randomized, investigator-blinded study was performed between January 2016 and December 2016. Patients for therapeutic colonoscopy were prospectively enrolled and assigned to either the vibrator group or walking group. Patients who refused to participate in this study as part of the experimental group consented to register in the control group instead. During the preparation period, patients assigned to the walking group walked ≥3,000 steps, whereas those assigned to the vibrator group received abdominal vibrator stimulation and restricted walking. All patients received the same colon cleansing regimen: 4-L split-dose polyethylene glycol (PEG) solution. @*Results@#Three hundred patients who received PEG solution for therapeutic colonoscopy were finally enrolled in this study (n=100 per group). Bowel cleansing with abdominal vibration stimulation showed almost similar results to that with walking exercise (Boston Bowel Preparation Scale score for the entire colon: vibrator vs walking vs control, 7.38±1.55 vs 7.39±1.55 vs 6.17±1.15, p<0.001). There were no significant differences between the vibrator group and walking group regarding instances of diarrhea after taking PEG, time to first diarrhea after taking PEG, total procedure time, and patient satisfaction. @*Conclusions@#This study indicates that, compared with conventional walking exercise, abdominal vibration stimulation achieved similar rates of bowel cleansing adequacy and colonoscopy success without compromising safety or patient satisfaction.

Impact of previous metronidazole exposure on metronidazole-based second-line quadrupletherapy for Helicobacter pylori infection

Background/Aims@#The negative effects on the eradication success of Helicobacter pylori infection after previous exposure to macrolides, including clarithromycin on clarithromycin-based first-line therapy have been demonstrated. However,whether this is true for metronidazole-based second-line quadruple therapy remains unclear. We investigated the relationship between past administration of metronidazole and the failure of metronidazole-based second-line quadruple therapy in patients with H. pylori infection. Methods: Patients over 20 years of age who were diagnosed with H. pylori infection between January 1998 and March 2016 were enrolled in this study. The relationship between the clinical parameters and the results of a C13-urea breath test after metronidazole-based second-line quadruple therapy was analyzed in patients for whom clarithromycin-based triple therapy failed to eradicate H. pylori . @*Results@#The H. pylori eradication failure rate was significantly higher in patients with a history of metronidazole use than in patients without a history of metronidazole use ( p = 0.011). Multivariable analysis showed that the odds ratio of previous metronidazole use for eradication failure was 3.468 (95% confidence interval,1.391 to 8.649; p = 0.008). In the subgroup analysis of patients with a history of metronidazole use, the duration of metronidazole use and interval between its use and eradication therapy did not significantly affect H. pylori eradication failure. @*Conclusions@#Previous exposure to metronidazole was a significant risk factor for treatment failure of metronidazole-based second-line quadruple therapy; therefore, this should be considered when establishing a treatment strategy for patients with H. pylori infection.

A Proposal for Modification of the Barcelona Clinic Liver Cancer Staging System Considering the Prognostic Implication of Performance Status

BACKGROUND/AIMS: Barcelona Clinic Liver Cancer (BCLC) C stage demonstrates considerable heterogeneity because it includes patients with either symptomatic tumors (performance status [PS], 1–2) or with an invasive tumoral pattern reflected by the presence of vascular invasion (VI) or extrahepatic spread (EHS). This study aimed to derive a more relevant staging system by modification of the BCLC system considering the prognostic implication of PS. METHODS: A total of 7,501 subjects who were registered in the Korean multicenter hepatocellular carcinoma (HCC) registry database from 2008 to 2013 were analyzed. The relative goodness-of-fit between staging systems was compared using the Akaike information criterion (AIC) and integrated area under the curve (IAUC). Three modified BCLC (m-BCLC) systems (#1, #2, and #3) were devised by reducing the role of PS. RESULTS: As a result, the BCLC C stage, which includes patients with PS 1–2 without VI/EHS, was reassigned to stage 0, A, or B according to their tumor burden in the m-BCLC #2 model. This model was identified as the most explanatory and desirable model for HCC staging by demonstrating the smallest AIC (AIC=70,088.01) and the largest IAUC (IAUC=0.722), while the original BCLC showed the largest AIC (AIC=70,697.17) and the smallest IAUC (IAUC=0.705). The m-BCLC #2 stage C was further subclassified into C1, C2, C3, and C4 according to the Child-Pugh score, PS, presence of EHS, and tumor extent. The C1 to C4 subgroups showed significantly different overall survival distribution between groups (p<0.001). CONCLUSIONS: An accurate and relevant staging system for patients with HCC was derived though modification of the BCLC system based on PS.

Negative Histology after Endoscopic Resection: An Endoscopist's Aspect / 대한Helicobacter연구학회지

Endoscopic submucosal dissection (ESD) is accepted as the standard treatment for gastric epithelial dysplasia or early gastric cancer because it enables curative en bloc resection and complete histopathological assessment of the specimen. However, occasionally, a tumorous lesion may not be detected, and histopathological discrepancies can occur after ESD. Reportedly, the prevalence of negative histopathological results after endoscopic resection is 2.0~4.4%. Negative histopathological results after endoscopic resection are commonly attributable to complete removal of the lesion via an endoscopic forceps biopsy (EFB) at the time of the initial diagnostic endoscopic examination, an initial histopathological overestimation of the EFB specimen, and incorrect localization of the original tumor with subsequent ESD performed at a wrong site. A small tumor size and surface area are known to be significant endoscopic predictors of negative histopathological results after ESD. Therefore, clinicians should be mindful of the fact that negative histopathological findings observed after endoscopic resection warrant a comprehensive review of all pre-ESD data and an adequate follow-up to determine the cause of these findings and to detect any possibility of local recurrence.

Non-steroidal anti-inflammatory drug-induced enteropathy

Non-steroidal anti-inflammatory drugs (NSAIDs) are well known to be associated with serious upper gastrointestinal complications, such as peptic ulcer, bleeding, perforation, and obstruction. Recently, attention has been mainly focused on the small bowel injuries caused by NSAIDs, and new endoscopic techniques such as capsule endoscopy and double balloon endoscopy can help in detecting such injuries. This article reviewed the epidemiology, pathogenesis, clinical manifestations, diagnosis, and treatment of small bowel injuries caused by NSAIDs. Small bowel injures by NSAIDs might occur with a similar frequency and extent as those observed in the upper gastrointestinal tract. The pathogenesis of NSAID-induced enteropathy is complex and not clearly understood. The various lesions observed in the small bowel, including petechiae, reddened folds, loss of villi, erosions, and ulcers can be detected by capsule endoscopy. A drug that could prevent or treat NSAID-induced enteropathy has not yet been developed. Therefore, further investigations should be performed to elucidate the pathogenesis of such enteropathy and develop suitable preventive and treatment strategies.

Diagnostic Approaches for Patients with Dyspepsia / 대한내과학회지

No abstract available.

Prediction of Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis Using 4-Hour Post-Endoscopic Retrograde Cholangiopancreatography Serum Amylase and Lipase Levels

Early post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP) prediction may allow safe same-day outpatients discharge after ERCP and earlier proper management. This study aimed to assess the usefulness of the 4-hour post-ERCP serum amylase and lipase levels for PEP early prediction and to investigate predictive cut-off values for 4-hour post-ERCP serum amylase and lipase levels for safe discharge and urgent initiation of resuscitation. The data of 516 consecutive patients with native papilla who underwent ERCP between January 2013 and August 2014 were retrospectively reviewed. Serum amylase and lipase levels were measured before, and 4 and 24 hours after ERCP. PEP occurred in 16 (3.1%) patients. The receiver-operator characteristic curve for 4-hour post-ERCP serum amylase and lipase levels showed that the areas under the curve were 0.919 and 0.933, respectively, demonstrating good test performances as predictors for PEP (both P values 1.5 × the upper limit of reference (ULR) was found useful for PEP exclusion with a sensitivity of 93.8%, while 4 × ULR was found useful to guide preventive therapy with the best specificity of 93.2%. Similarly, the lipase level 2 × ULR showed best sensitivity, while 8 × ULR had the best specificity. Logistic regression analysis showed that 4-hour post-ERCP amylase level > 4 × ULR, lipase level > 8 × ULR, precut sphincterotomy, and pancreatic sphincterotomy were significant predictors for PEP. In conclusion, 4-hour post-ERCP amylase and lipase levels are useful early predictors of PEP that can ensure safe discharge or prompt resuscitation after ERCP.

Recent development of innovative resection methods for gastric neoplasms using hybrid natural orifice transluminal endoscopic surgery approach

There have been an evolutionary development with respect to the resection modality for the treatment of the gastric neoplasms such as gastric subepithelial tumors (SETs) or early gastric cancers (EGCs). Hybrid natural orifice transluminal endoscopic surgery (hybrid NOTES) played a central role in the process of development. In the earlier period, the non-exposure type hybrid NOTES such as laparoscopy and endoscopy cooperative surgery (LECS), endoscope-assisted wedge resection (EAWR), and laparoscopy-assisted endoscopic full-thickness resection (LAEFTR) has been introduced by several investigators. However, a concern about a spillage of gastric content including the tumor cells has been continuously raised among the clinicians. Accordingly, the non-exposure type hybrid NOTES such as combination of laparoscopic and endoscopic approaches to neoplasia with a non-exposure technique (CLEAN-NET), non-exposed endoscopic wall-inversion surgery (NEWS), and hybrid neo-endoscopic full-thickness resection (hybrid neo-EFTR) have been developed to the clinicians. Although most of studies about hybrid NOTES for the treatment of the gastric neoplasms have a small number of patients and require further validations, those are enough to receive our attention. Here, we describe and summarize the development process of the innovative resection methods for gastric neoplasms using hybrid NOTES approach.

Impact of prior lamivudine use on the antiviral efficacy and development of resistance to entecavir in chronic hepatitis B patients

BACKGROUND/AIMS: To determine the efficacies of entecavir (ETV) in nucleos(t)ide analogue (NA)-naive chronic hepatitis B (CHB) patients and in those with prior lamivudine (LAM) use who did not develop resistance. METHODS: We retrospectively enrolled 337 patients with CHB who were treated with ETV (0.5 mg daily) for at least 30 months. The study included 270 (80.1%) NA-naive patients and 67 (19.9%) LAM-use patients. Ten of the LAM-use patients were refractory to LAM therapy without developing resistance. RESULTS: Genotypic resistance to ETV developed more frequently in the LAM-use group (13.1%) than in the NA-naive group (2.6%) at 60 months (P=0.009). In subgroup analysis, after excluding the 10 patients who were refractory to LAM therapy, the cumulative probability of ETV resistance did not differ significantly between the two groups (P=0.149). Prior LAM refractoriness and a higher hepatitis B virus DNA level at month 12 were independent predictive factors for the development of ETV resistance. CONCLUSIONS: ETV resistance developed more frequently in LAM-use patients with CHB. However, prior LAM use without refractoriness did not affect the development of ETV resistance. The serum hepatitis B virus DNA level at month 12 was a major predictor for the development of ETV resistance.

Rupture of a Superior Mesenteric Artery Pseudoaneurysm Presenting with Asymptomatic Anemia / 대한내과학회지

Anemia is a common cause of referrals to gastroenterologists. Only a small number of anemia cases result from vascular abnormalities. Visceral artery aneurysms and pseudoaneurysms are rare forms of vascular disease that have significant potential for rupture, resulting in potentially life-threatening hemorrhaging. We present the case of a 70-year-old female patient with a pseudoaneurysm of the superior mesenteric artery complicated with rupture, who had no abdominal pain and only anemia.

Preoperative Colonoscopy for Detection of Synchronous Neoplasms after Insertion of Self-Expandable Metal Stents in Occlusive Colorectal Cancer: Comparison of Covered and Uncovered Stents

BACKGROUND/AIMS: In patients with occlusive colorectal cancers, a complete preoperative evaluation of the colon proximal to the obstruction is often impossible. We aimed to evaluate the feasibility of preoperative colonoscopy after stent placement and to determine whether the success rate of colonoscopy differs between covered and uncovered stents. METHODS: Seventy-three patients with malignant colorectal obstruction were enrolled prospectively. In patients with a resectable cancer, a preoperative colonoscopy was performed after insertion of a self-expandable metal stent (SEMS). The success rate of complete preoperative colonoscopy was compared between covered and uncovered stents. RESULTS: Forty-five of 73 patients who underwent stent placement had a resectable cancer (61.6%). A complete preoperative colonoscopy was possible in 40 of 45 patients (88.9%). The success rate of complete preoperative colonoscopy was significantly lower in the covered-stent group when the obstructing mass lesion was located in the sigmoid colon (p=0.024). Synchronous cancer was detected in one patient (2.2%). Stent migration was observed in four patients with a covered stent. CONCLUSIONS: A preoperative complete colonoscopy after SEMS placement was feasible and safe in most patients with malignant colorectal obstruction. Uncovered stents seem to have more advantages than covered stents in preoperative colonoscopy proximal to the obstruction.

Nodular lymphoid hyperplasia of the stomach in a patient with multiple submucosal tumors

Nodular lymphoid hyperplasia of the stomach is a rare lymphoproliferative disorder. Here, we report a 38-year-old man who presented with multiple submucosal tumors of the stomach. Histologically, the lesions were characterized by multiple discrete submucosal nodules of lymphoid cells. The infiltrates between the lymphoid follicles were composed mainly of medium-sized lymphoid cells with abundant clear cytoplasm, as well as a few large cells with vesicular nuclei. The gastric mucosa exhibited multifocal lymphoid aggregates and some of the epithelial cells were infiltrated by small lymphocytes mimicking lymphoepithelial lesions. Histopathology was consistent with mucosa-associated lymphoid tissue lymphoma. However, the infiltrating lymphoid cells were positive for CD2, CD3, CD5, and CD7. In addition, polymerase chain reaction analysis of the immunoglobulin heavy chain and T-cell receptor gene rearrangements demonstrated polyclonality. This case was diagnosed as reactive lymphoid hyperplasia of the stomach.

Insertion of Self Expandable Metal Stent for Malignant Stomal Obstruction in a Patient with Advanced Colon Cancer

Self expandable metal stent can be used both as palliative treatment for malignant colorectal obstruction and as a bridge to surgery in patients with potentially resectable colorectal cancer. Here, we report a case of successful relief of malignant stomal obstruction using a metal stent. A 56-year-old man underwent loop ileostomy and was given palliative chemotherapy for ascending colon cancer with peritoneal carcinomatosis. Eight months after the surgery, he complained of abdominal pain and decreased fecal output. Computed tomography and endoscopy revealed malignant stomal obstruction. Due to his poor clinical condition, we inserted the stent at the stomal orifice, instead of additional surgery, and his obstructive symptoms were successfully relieved. Stent insertion is thought to be a good alternative treatment for malignant stomal obstruction, instead of surgery.

G-Protein Beta3 Subunit C825T Polymorphism in Patients With Overlap Syndrome of Functional Dyspepsia and Irritable Bowel Syndrome

BACKGROUND/AIMS: Guanine nucleotide binding protein (G-protein) beta polypeptide 3 (GNB3) C825T polymorphism alters intracellular signal transduction, which may lead to motor or sensory abnormalities of the gastrointestinal tract. The aim of the present study was to evaluate the association of the GNB3 C825T polymorphism with susceptibility to overlap syndrome of functional dyspepsia (FD) and irritable bowel syndrome (IBS) in a Korean population. METHODS: One hundred sixty-seven patients with FD alone, 60 patients with IBS alone, 85 patients with the overlap of FD and IBS, and 434 asymptomatic healthy subjects participated in the study. Genotyping for GNB3 C825T polymorphism was performed using their blood samples. RESULTS: No association of GNB3 genotypes in patients with FD alone, IBS alone or overlap phenotype, when compared to genotypes in controls, was detected. The frequency of CT and TT genotypes relative to the CC genotype for the phenotypes of FD alone, IBS alone and the coexistence of FD and IBS did not significantly differ. Comparison of the TT genotype with the CC/CT genotype showed no significant association for each phenotype group. CONCLUSIONS: There is no apparent association of the GNB3 C825T polymorphism with the susceptibility to FD, IBS or the overlap of FD and IBS. Larger-scale studies and further investigation on other candidate genes are required.

Endoscopic Treatment of 3 Cases of GIST with High Aggressive Behavior / 대한소화기내시경학회지

Gastrointestinal stromal tumors (GISTs) are the most common subepithelial tumor of the gastrointestinal tract. They originate from mesenchymal tissue. Because of difficulties in discriminating between benign and malignant GISTs, the treatment modality is selected on the base of tumor size, mitosis count, location, originating layer, and the presence of complications. Regular follow-up, open resection, or laparoscopic operation were considered main treatments for GISTs. Surgical resection is standard treatment for a huge GIST. However, the treatment method is not determined for GISTs of less than 3 cm that show a benign clinical course. Recently, endoscopic treatment was attempted because of recent endoscope developments and associated devices. We report three cases of gastric GISTs with a high risk of aggressive behavior that were successfully treated by endoscopic resection.

Temporary Placement of a Newly Designed, Fully Covered, Self-Expandable Metal Stent for Refractory Bile Leaks

Bile leaks remain a significant cause of morbidity for patients undergoing laparoscopic cholecystectomy. Leakage from an injured duct of Luschka (subvesical duct) follows the cystic duct as the most common cause of postcholecystectomy bile leaks. Although endoscopic sphincterotomy, plastic-stent placement, or nasobiliary-drain placement are effective in healing biliary leaks, in patients in whom leakage persists and the symptoms worsen despite conventional endoscopic treatment, re-exploration with laparoscopy and ligation of the injured subvesical duct should be considered. We present herein the case of a 31-year-old woman with refractory bile leakage from a disrupted subvesical duct after cholecystectomy that could not be managed with endoscopic sphincterotomy and plastic-stent placement. A newly designed, fully covered, self-expandable metal stent (FC-SEMS) was successfully placed for the treatment of refractory bile leaks in this patient. It appears that temporary placement of an FC-SEMS is technically feasible and provides an effective alternative to surgical therapy for refractory bile leaks after cholecystectomy.

Jejunal Metastasis of Lung Cancer Diagnosed with Double Balloon Enteroscopy / 대한소화기내시경학회지

Metastasis from lung cancer to the small bowel is rare and this accounts for 0.2% to 0.5% of all the cases of metastasis from lung cancer. In most cases, the patients are asymptomatic and they can show signs of bleeding, intestinal obstruction, perforation and so on. A better diagnostic approach to the small bowel has recently been made possible through capsule endoscopy and double balloon enteroscopy (DBE), and they have a higher diagnostic rate for small bowel bleeding compared with that of the previous diagnostic tests. DBE makes it possible to diagnose precisely due to the high quality endoscopic images and biopsy specimens. In addition, therapeutic DBE with a 2.8 mm channel enables performing more kinds of therapeutic procedures than diagnostic DBE with a 2.2 mm channel. If small bowel metastasis is suspected on 18FDG-PET/CT, then DBE can be considered for making a pathologic diagnosis. We report here on a case of small bowel metastasis from non small cell lung cancer in a 39-year-old woman who complained of hematochezia and we review the relevant literature.

Clinical Characteristics of Gastrointestinal Carcinoid Tumors / 대한소화기내시경학회지

BACKGROUND/AIMS: Various factors have been reported that can predict the clinical course and outcome of patients with gastrointestinal (GI) carcinoid tumors. We analyzed the clinical characteristics of GI carcinoid tumors and the factors associated with metastasis. METHODS: We retrospectively analyzed the clinical manifestations, treatment modalities and prognosis of 83 patients with GI carcinoid tumors. RESULTS: The mean age of the patients was 48 years old. The locations of the carcinoid tumors were rectum (n=60), stomach (n=12), duodenum (n=6), appendix (n=4) and colon (n=1). The most common symptom was non-specific (n=65, 79.5%), and the mean tumor size was 11.2 mm. The main treatment modality was endoscopic resection (n=66, 79.5%). Nine patients showed metastasis, and all of their tumors were larger than 2 cm. Univariate analysis revealed that size, ulceration and invasion of the proper muscle layer were significant factors associated with metastasis. Tumor size (p=0.001) was the only independent factor on multivariate analysis. CONCLUSIONS: The diagnosis of small sized, asymptomatic GI carcinoid tumors has increased and endoscopic treatment was a useful modality. Tumor size was a predictive factor for metastasis.