Joon Koo Kang

The relationship between the failure to eradicate Helicobacter pylori and previous antibiotics use.

BACKGROUND The previous use of antibiotics is known to correlate positively with antibiotic resistance; whether this is also the case in the eradication of Helicobacter pylori infection is unclear. AIM To investigate the relationship between the previous use of antibiotics and the failure of eradication therapy in H. pylori infection. METHODS The relationship between the clinical parameters and the failure of H. pylori eradication was analyzed in patients administered standard triple therapy and then assessed for the eradication of H. pylori based on a C13-urea breath test. RESULTS In a multivariate analysis, failure rates increased significantly in patients with a history of clarithromycin (odds ratio [OR], 4.445) or other macrolides (OR, 2.407) use, who were female (OR, 1.339), or who were older than 60 years of age (OR, 1.326). The eradication failure rate in patients with a history of macrolides use for >2 weeks was significantly higher than if the duration of use was <2 weeks (44.8% vs. 29.3%, p=0.047). CONCLUSIONS A patients history of macrolides is a useful predictor of the likelihood of standard triple therapy failure in H. pylori eradication. The alternatives such as a bismuth-based quadruple or a levofloxacin-containing therapy should be considered in patients treated with macrolides for >2 weeks.

Partially covered versus uncovered self-expandable nitinol stents with anti-migration properties for the palliation of malignant distal biliary obstruction: A randomized controlled trial

Abstract Objective. Covered self-expandable metal stents (SEMSs) are increasingly used as alternatives to uncovered SEMSs for the palliation of inoperable malignant distal biliary obstruction to counteract tumor ingrowth. We aimed to compare the outcomes of partially covered and uncovered SEMSs with identical mesh structures and anti-migration properties, such as low axial force and flared ends. Materials and methods. One hundred and three patients who were diagnosed with inoperable malignant distal biliary obstruction between January 2006 and August 2013 were randomly assigned to either the partially covered (n = 51) or uncovered (n = 52) SEMS group. Results. There were no significant differences in the cumulative stent patency, overall patient survival, stent dysfunction-free survival and overall adverse events, including pancreatitis and cholecystitis, between the two groups. Compared to the uncovered group, stent migration (5.9% vs. 0%, p = 0.118) and tumor overgrowth (7.8% vs. 1.9%, p = 0.205) were non-significantly more frequent in the partially covered group, whereas tumor ingrowth showed a significantly higher incidence in the uncovered group (5.9% vs. 19.2%, p = 0.041). Stent migration in the partially covered group occurred only in patients with short stenosis of the utmost distal bile duct (two in ampullary cancer, one in bile duct cancer), and did not occur in any patients with pancreatic cancer. Conclusions. For the palliation of malignant distal biliary obstruction, endoscopic placement of partially covered SEMSs with anti-migration designs and identical mesh structures to uncovered SEMSs failed to prolong cumulative stent patency or reduce stent migration.

Laparoscopy-Assisted Endoscopic Full-Thickness Resection with Basin Lymphadenectomy Based on Sentinel Lymph Nodes for Early Gastric Cancer

Gastric cancer is one of the most common malignant tumors worldwide. The incidence of gastric cancer in East Asia, including Korea and Japan, is higher than in other regions, so the screening system in these regions has evolved to diagnose those with gastric cancer at an early stage. 1 Therefore, the proportion of patients with early gastric cancer (EGC) in these areas has recently increased. Patients with EGC have an excellent prognosis after curative resection, owing to low rates of lymph node metastasis and distant recurrence in the peritoneum and liver relative to patients with advanced-stage gastric cancer. Because lymph node metastasis is limited to a small number of perigastric lymph nodes even in EGC, some patients have been treated with limited (D1þ) lymphadenectomy. 2 In contrast with standard surgical procedures that include extended (D2) lymphadenectomy for gastric cancer, D1þ lymphadenectomy can be easily performed to reduce postoperative morbidity. 3 However, despite this, a total or subtotal gastrectomy should still be performed for EGC because a D1þ lymphadenectomy includes lymph nodes around the major vessels feeding the stomach. Extensive gastric resection that includes resection of the pylorus and autonomic nerve fibers can have a negative impact on quality of life after surgery, owing to reflux gastritis and uncontrolled bowel movements. Considering the long survival time of patients with EGC, function of the stomach should be maintained after complete resection of gastric cancer. One of the evolving modalities to maintain gastric function after removal of gastric cancer is endoscopic resection. Although endoscopic resection has been reserved for patients with EGC who are very unlikely to have metastatic lymph nodes, the proportion of gastric cancer patients treated with endoscopic resection has gradually increased as more patients are being diagnosed with EGC. 4 Development of the endoscopic resection technique can eliminate the limitation with regard to the range of en bloc resection in cases of mucosal cancers without metastatic lymph nodes, and furthermore expand the depth of resection into the submucosal layer. 5 Therefore, several gastroenterologists have been performing endoscopic resections using the extended criteria for this procedure suggested by previous reports. 2,6 However, despite the many benefits regarding quality of life, the temerarious use of endoscopic resection should be limited due to the lack of clinical evidence and limited ability for the identification of metastatic lymph nodes. On the other hand, if it becomes possible to confirm lymph node status and to perform minimal lymph node dissection for patients with EGC who meet the expanded indications for endoscopic treatment, then local resection

Non-neoplastic pathology results after endoscopic submucosal dissection for gastric epithelial dysplasia or early gastric cancer

BACKGROUND AND STUDY AIMS Endoscopists sometimes face paradoxical cases in which the endoscopic submucosal dissection (ESD) specimen reveals a non-neoplastic pathology result. The aims of the study were to determine the reasons for such results, and to compare the endoscopic characteristics of non-neoplastic and conventional neoplastic pathology groups after ESD. PATIENTS AND METHODS A total of 1186 gastric ESDs performed between February 2005 and December 2011 were retrospectively reviewed. The ESD specimens included 52 (4.4 %) that were confirmed as negative or indefinite for neoplasia. Patient characteristics and endoscopic and pathological data were reviewed and compared. RESULTS Non-neoplastic pathology after ESD was due to complete removal of the lesion at biopsy in 45 cases (86.5 %), pathology overestimation in 5 (9.6 %), and incorrect localization of the original tumor with subsequent ESD performed at the wrong site in 2 (3.8 %). The mean length and surface area of the non-neoplastic lesions were 9.2 ± 2.6 mm and 49.6 ± 23.6 mm (2), respectively. Mean sampling ratios were 3.0 ± 1.5 mm/fragment and 16.3 ± 10.0 mm(2)/fragment. Compared with 1134 cases confirmed as neoplastic on the final ESD specimen, non-neoplastic cases showed a significantly smaller tumor size and surface area, and lower sampling ratios in a logistic regression analysis adjusted for potential confounders (P < 0.001 for all). CONCLUSIONS Complete lesion removal by biopsy, pathology overestimation, and incorrect localization of the original tumor with subsequent ESD at the wrong site were the main reasons for non-neoplastic results after ESD. Small tumor size and surface area, and low sampling ratios were associated with non-neoplastic pathology results after ESD.

Laparoscopy-assisted endoscopic full-thickness resection for gastric subepithelial tumors originated from the muscularis propria layer: a pilot study with literature review

Abstract Objective: Laparoscopy-assisted endoscopic full-thickness resection (LAEFTR) has been suggested as an alternative to laparoscopic wedge resection in the treatment of gastric subepithelial tumors (SETs). It is expected to minimize the resection of the tissue surrounding the tumors and maintain the function of the remnant stomach. Here, we performed a prospective pilot study to evaluate the efficacy of laparoscopy-assisted endoscopic full-thickness resection (LAEFTR) for patients with gastric SETs. Material and methods: We enrolled twelve patients who were diagnosed with gastric SETs with an intraluminal growth pattern or which is located in the gastric antrum between October 2011 and September 2013. LAEFTR was performed endoscopically using an endoscopic knife to make an incision half way around the tumor circumference and a laparoscopic resection around the remaining tumor circumference, followed by its laparoscopic removal. The feasibility, safety, and effectiveness of LAEFTR for gastric SETs were evaluated. Results: The median size of the tumors in twelve patients was 22 mm (21–33). Of the 12 patients, 8 received LAEFTR, while the others underwent conventional laparoscopic wedge resection, since their tumor outlines were clearly visible in laparoscopic view. In 8 patients who underwent LAEFTR, the mean total operation time (endoscopic procedure time/laparoscopic procedure time) were 117 (37/41) min. The tumors were completely resected with clear margin, and there was no perioperative and postoperative complications. Conclusions: LAEFTR currently seems to be the ideal treatment modality of intraluminal gastric SETs where their resection margins are difficult to define under laparoscopic guidance alone.

[Factors affecting initial virologic response and emergence of resistant mutants after adefovir treatment in lamivudine-resistant chronic hepatitis B patients].

BACKGROUND/AIMS Adefovir dipivoxil (adefovir) effectively inhibits both wild-type and lamivudine-resistant hepatitis B virus (HBV) replication. The development of adefovir resistance is both delayed and infrequent compared with lamivudine resistance. The aim of this study was to characterize the serologic, biochemical, and virologic response to adefovir, and to explore the factors affecting initial virologic response (IVR, defined as a decrease in serum HBV below 4 log10copies/mL after 6 month of treatment) and adefovir resistance in lamivudine resistant HBV-infected patients. METHODS This study population comprised 76 patients with lamivudine-resistance who had received adefovir for more than 12 months between March 2004 and December 2006. The adefovir-resistant mutant was assayed at 6 months and 12 months during adefovir administration. Restriction-fragment mass polymorphism analysis was used for detecting YMDD and adefovir mutants. RESULTS After adefovir administration, an IVR was observed in 31% of the patients with lamivudine resistance. Factors associated with an IVR were HBeAg negativity (P=0.04) and the presence of liver cirrhosis (P=0.04). Age, sex, pretreatment levels of alanine aminotransferase and aspartate aminotransferase, pretreatment HBV DNA levels, presence of precore mutation, and type of YMDD mutants were not related to an IVR during adefovir treatment. The prevalence of adefovir resistance was 5% and 13% at 6 months and 12 months after therapy, respectively. Mixed infection of the precore mutant was a risk factors for the emergence of adefovir resistance (P=0.01). CONCLUSIONS Lamivudine-resistant HBV patients exhibiting HBeAg negativity and liver cirrhosis were more likely to achieve an IVR after adefovir therapy. Adefovir resistance was associated with mixed infection of the precore mutant.

Cyclic Change of Sphincter of Oddi Motility and Its Relationship with Small Bowel Migrating Motor Complex in Humans

BackgroundSeveral animal and human studies have reported that sphincter of Oddi (SO) motility shows cyclical changes during the fasting state. However, to date, the relationship between the SO motility and the migrating motor complex (MMC) of the small bowel (SB) remains unclear in humans.AimsWe observed SO motility over a long study period and evaluated its relationship with the MMC of the SB in humans using percutaneous long-term manometry.MethodsOur study included patients with hepatolithiasis who required percutaneous transhepatic catheter placement and subsequently underwent choledochoscopy and stone removal. Long-term percutaneous transhepatic SO manometry was performed after complete stone removal. SO and SB motility were simultaneously recorded.ResultsSO motility showed cyclical phasic changes with periodic high-frequency contractions similar to the MMC contractions of the SB. All high-frequency contractions of the SO coincided with phase III contractions of the MMC of the SB. The proportions of phase III contractions of SO and SB were similar, but the proportions of phase I (P = 0.001) and phase II (P = 0.002) contractions were significantly different. The mean basal SO pressure was observed to significantly increase in phase III compared to phase I (P = 0.001) and phase II (P = 0.001) contractions.ConclusionsSO motility in humans showed cyclical phasic changes closely coordinated with the MMC of the SB in a fasting state; however, the proportion of phases differed between the SO and the SB. The basal pressure significantly increased during physiological high-frequency phase III contractions of the SO.

A Case of Amyloidosis Presenting as Chronic Cholecystitis, Misdiagnosed as Polymyalgia Rheumatica

Amyloidosis is a rare disease defined by extracellular deposits of amorphous fibrillar proteins, derived from aggregations of misfolded proteins. Localization of amyloidosis in the gallbladder is uncommon; only eight cases have been reported. We describe a case of amyloidosis diagnosed by cholecystectomy, which possibly also affected the liver and kidney. The patient was misdiagnosed with polymyalgia rheumatica, but after a cholecystectomy to treat chronic cholecystitis, we ultimately diagnosed him with amyloidosis. We review amyloidosis with gallbladder involvement in the literature.