Colon Polyp Detection in Primary Health Care Institutions of Korea: Detection Rate and Issues with Following the Guidelines.

Background/Aims: There have been few multicenter studies on colonic polyps conducted by primary medical institutions. This study examined the detection rate of colonic polyps in primary health care institutions and the related factors while following the guidelines. Methods: The medical records of 14,029 patients who underwent colonoscopy between January-June 2020 at 40 primary medical institutions in Korea were analyzed. High-risk adenoma was defined as advanced adenoma, carcinoma, or ≥3 adenomas. Results: Most patients (71.2%) aged ≥50 years underwent re-colonoscopy within 5 years (51.3%) for diagnostic purposes (61.3%) in Korean primary medical institutions. The detection rates of colon polyps, adenoma, advanced adenoma, high-risk adenoma, and carcinoma was 59.9%, 38.9%, 5.9%, 11.4%, and 0.3% in all subjects and 59.8%, 37.5%, 8.5%, 12.9%, and 0.3% in average-risk patients, respectively. The incidences of adenoma in average-risk patients increased significantly with age (30s/40s/50s: 20.1%/29.4%/43% for adenoma, 4.4%/6.7%/10.3% for advanced adenoma, and 5.6%/9.5%/14.6% for high-risk adenoma; p<0.05). Before 50 years of age, high-risk adenoma was detected in 9.1% of patients in the first-time screening group, and the significant risk factors were being male and ≥40 years of age. The detection rate of high-risk adenoma in the normal index colonoscopy group within 5 years was 9.0%. The significant risk factors included older age, male sex, positive fecal occult blood test, stool form changes, and nonspecific symptoms (gas and indigestion). Conclusions: More colonic adenoma studies targeting real-world clinical practice will be needed to revise the Korean guidelines for colorectal cancer screening and surveillance.

Development of Biliary and Enteral Stents by the Korean Gastrointestinal Endoscopists.

Stenting in the gastrointestinal tract is a common procedure used for palliation of obstruction in the enteral and biliary tract. Today, stenting of malignant and benign strictures is performed at almost every major tertiary hospital in Korea. Moreover, Korea has become a major global supplier of cutting edge technology in the field of self-expanding metal stents. However, the history of stenting in Korea is relatively short and was far behind that of other nations such as Japan and Germany. The authors are humbled and gratified to have been able to observe the development and application of these stents in Korea, first hand. In this article, the authors review the overall history of stenting with a specific focus on the development of stenting in Korea. The development of esophageal, gastroduodenal, biliary, and colonic stents in Korea are reviewed in this article from a chronological and historical point of view, and a personal account of some of the significant moments of stent development in Korea are described.

High-resolution Impedance Manometry Criteria in the Sitting Position Indicative of Incomplete Bolus Clearance.

BACKGROUND/AIMS: We used high-resolution impedance manometry (HRIM) to determine the length of breaks on the isobaric contour which would predict incomplete bolus clearance in patients in the sitting position. METHODS: In total, 651 swallows in 71 patients with esophageal symptoms were studied using a solid-state HRIM system in the sitting position. Each swallow was classified as complete or incomplete bolus clearance by impedance criteria and peristaltic integrity was evaluated using 20- and 30-mmHg pressure topography isobaric contours. Correlations between the lengths of the breaks for 20- and 30-mmHg were analyzed. RESULTS: Complete bolus clearance was observed in 83.3% (542/651) of swallows. Breaks of 3 and 7 cm or less were associated with a bolus clearance of 96.8% on the 20-mmHg and 94.7% on the 30-mmHg isobaric contour, respectively (P < 0.001). The areas under the ROC curves for the 20 and 30 mmHg isobaric contours were 0.900 and 0.950, respectively. The sensitivity and specificity for complete bolus clearance were 75.6% and 89.3% for breaks 3 cm or less on the 20-mmHg isobaric contour and 87.9% and 78.7% for breaks 7 cm or less on the 30-mmHg contour (P < 0.001). CONCLUSIONS: Breaks of < 3 cm in the 20-mmHg isobaric contour or < 7 cm in the 30-mmHg isobaric contour were associated with com-plete bolus clearance. The threshold for breaks in the sitting position was greater than previous reports using the supine posi-tion and longer breaks predicted incomplete bolus clearance.(J Neurogastroenterol Motil 2014;20:491-496).

Clinically useful diagnostic tool of contrast enhanced ultrasonography for focal liver masses: comparison to computed tomography and magnetic resonance imaging.

BACKGROUND/AIMS: To evaluate the diagnostic value of contrast (SonoVue(®)) enhancement ultrasonography (CEUS) and to compare this method with computed tomography (CT) and magnetic resonance imaging (MRI) in evaluating liver masses. METHODS: CEUS (n=50), CT (n=47), and MRI (n=43) were performed on 50 liver masses in 48 patients for baseline mass haracterization. The most likely impression for each modality and the final diagnosis, based on the combined biopsy results (n=14), angiography findings (n=36), and clinical course, were determined. The diagnostic value of CEUS was compared to those of CT and MRI. RESULTS: The final diagnosis of the masses was hepatocellular carcinoma (n=43), hemangioma (n=3), benign adenoma (n=2), eosinophilic abscess (n=1), and liver metastasis (n=1). The overall diagnostic agreement with the final diagnosis was substantial for CEUS, CT, and MRI, with κ values of 0.621, 0.763, and 0.784, respectively. The sensitivity, specificity, and accuracy were 83.3%, 87.5%, and 84.0%, respectively, for CEUS; 95.0%, 87.5%, and 93.8%, respectively, for CT; and 94.6%, 83.3%, and 93.0%, respectively for MRI. After excluding the lesions with poor acoustic sonographic windows, the sensitivity, specificity, and accuracy for CEUS were 94.6%, 87.5%, and 93.3%, respectively, with a κ value of 0.765. CONCLUSIONS: If an appropriate acoustic window is available, CEUS is comparable to CT and MRI for the diagnosis of liver masses.

Gastric schwannoma diagnosed by endoscopic ultrasonography-guided trucut biopsy.

Schwannomas of the gastrointestinal (GI) tract are rare subepithelial tumors comprising approximately 3.3% to 12.8% of all mesenchymal tumors of the GI tract. On endoscopic ultrasound (EUS) they are seen as hypoechoic tumors arising most commonly from the 4th proper muscle layer. Although EUS helps to distinguish tumor characteristics, tissue sampling is required for differentiation with other more common tumors such as GI stromal tumors. Both EUS-guided fine needle aspiration and EUS-guided trucut biopsy (EUS-TCB) can be used for tissue sampling. However, only EUS-TCB allows core biopsy and a high yield of immunohistochemical staining. We report a case of a gastric schwannoma diagnosed by EUS-TCB.

Peroral endoscopic myotomy for treatment of achalasia: initial results of a korean study.

BACKGROUND/AIMS: Achalasia is a rare esophageal motility disorder. Recently, a novel endoscopic technique, peroral endoscopic myotomy (POEM), was introduced as an alternative treatment for achalasia. We report the results and short term outcomes of POEM for patients with achalasia. METHODS: POEM was performed in 13 patients with achalasia. The procedure consisted of creating a submucosal tunnel followed by endoscopic myotomy of circular muscle bundles. The mucosal entry was closed by conventional hemostatic clips. A validated clinical symptom score (Eckardt score) and high resolution manometry were used to evaluate the outcomes. RESULTS: Both the clinical score of achalasia, as well as the resting lower esophageal sphincter (LES) pressure, were significantly reduced after POEM. Mean posttreatment Eckardt score was 0.4±0.7, compared to 6.4±1.9 prior to the treatment (p=0.001). The mean pretreatment and posttreatment LES pressure was 30.3 and 15.3 mm Hg, respectively (p=0.007). Following POEM, symptomatic relief from dysphagia without reflux symptoms was observed in all patients (13/13). No serious complications related to POEM were encountered. CONCLUSIONS: Based upon our initial experience, the authors believe that POEM is a feasible, safe, and effective treatment and may possibly substitute established treatments of refractory achalasia.

Endoscopic resection of hypopharyngeal squamous cell carcinoma.

Hypopharyngeal cancers are often diagnosed at an advanced stage and have a poor prognosis. Even when they are diagnosed at an operable stage, surgery often results in substantial morbidity and decreased patients' quality of life. Although the endoscopic diagnosis of early hypopharyngeal cancer is difficult, recent developments in advanced imaging endoscopy have enabled easier diagnosis of these lesions. Endoscopic resection of early hypopharyngeal cancer is a potential minimally invasive treatment that can preserve the function and quality of life of patients. Reports of this procedure are limited, however. We report a case of hypopharygeal cancer treated with endoscopic resection.

The accuracy of probe-based confocal endomicroscopy versus conventional endoscopic biopsies for the diagnosis of superficial gastric neoplasia (with videos).

BACKGROUND: Probe-based confocal laser endomicroscopy (pCLE) allows real-time in vivo histologic evaluation of GI mucosal lesions. Although pCLE has been used for various GI disorders, the significance of pCLE for gastric lesions is largely unknown. OBJECTIVE: We compared the accuracy of conventional endoscopic forceps biopsy and pCLE for the diagnosis of superficial gastric neoplasia before endoscopic resection. DESIGN: Prospective comparative study. SETTING: Single tertiary referral center. PATIENTS: This study involved 54 superficial gastric neoplasias in 46 patients. MAIN OUTCOME MEASUREMENT: Accuracy of in vivo and offline pCLE diagnosis and interobserver agreement. METHODS: pCLE was performed before endoscopic resection of superficial gastric neoplasias previously diagnosed by endoscopic biopsy. The overall accuracy of endoscopic, in vivo pCLE, and offline pCLE diagnosis was compared with postendoscopic resection histopathology. RESULTS: Endoscopic resection was performed on 54 lesions. On final histopathology, there were 3 non-neoplastic lesions, 19 gastric dysplasias, 22 differentiated adenocarcinomas, and 10 undifferentiated adenocarcinomas. The overall agreement with the final histopathology was substantial for conventional biopsies (κ = 0.617) and excellent for in vivo pCLE (κ = 0.824) (P < .001). The overall accuracy for the diagnosis of adenocarcinoma was 91.7% for pCLE and 85.2% for conventional biopsies (P = .065). The combined accuracy of conventional endoscopic biopsies and pCLE was 98.1%. The interobserver agreement for offline pCLE diagnosis was excellent (κ = 0.931). LIMITATIONS: Single-center study, small sample size. CONCLUSION: Our study showed that pCLE can provide an accurate diagnosis for superficial gastric neoplasia. pCLE has the potential to compensate for the inherent limitations of a conventional endoscopic biopsy.

Intra-Abdominal Tuberculous Lymphadenitis Diagnosed Using an Endoscopic Ultrasonography-Guided ProCore Needle Biopsy.

Intra-abdominal tuberculous lymphadenitis can mimic a variety of other abdominal disorders such as pancreatic cancer, metastatic lymph nodes, or lymphoma, which can make a proper diagnosis difficult. A correct diagnosis of intra-abdominal tuberculous lymphadenitis can lead to appropriate management. Endoscopic ultrasonography (EUS)-guided needle biopsy may be the procedure of choice for tissue acquisition when onsite cytopathology examination is unavailable because it is essential to obtain sufficient material suitable for the examination using an ancillary method, such as flow cytometry, molecular diagnosis, cytogenetics, or microbiological culture. We report a case of intra-abdominal tuberculous lymphadenitis diagnosed using an EUS-guided, 22-gauge histology new needle biopsy without an onsite cytopathology examination.

ESD Hands-on Course Using Ex Vivo and In Vivo Models in South Korea.

Endoscopic submucosal dissection (ESD) is an established treatment for gastric neoplasias especially in regions with a high volume of gastric cancer. Although ESD has many advantages over endoscopic mucosal resection, ESD is technically more difficult and can result in severe complications. Therefore establishment of an effective training system is required to help endoscopists climb the ESD learning curve. Although a standard training system for ESD remains to be established, some centers are incorporating ex vivo and/or in vivo animal models to provide a safe and effective means of ESD training. However, it is unknown if these animal models are more effective than other programs. Moreover the efficacy of the animal model may vary according to socio-economic status and the volume of gastric cancer. In this article we introduce the basic and advanced ESD training model using the ex vivo and in vivo animal model from South Korea and review the associated literature from other regions.

Does immunohistochemical staining have a clinical impact in early gastric cancer conducted endoscopic submucosal dissection?

AIM: To evaluate clinicopathologic parameters and the clinical significance related lymphovascular invasion (LVI) by immunohistochemical staining (IHCS) in endoscopic submucosal dissection (ESD). METHODS: Between May 2005 and May 2010, a total of 348 lesions from 321 patients (mean age 63 ± 10 years, men 74.6%) with early gastric cancer (EGC) who met indication criteria after ESD were analyzed retrospectively. The 348 lesions were divided into the absolute (n = 100, differentiated mucosal cancer without ulcer ≤ 20 mm) and expanded (n = 248) indication groups after ESD. The 248 lesions were divided into four subgroups according to the expanded ESD indication. The presence of LVI was determined by factor VIII-related antigen and D2-40 assessment. We compared LVI IHCS-negative group with LVI IHCS-positive in each group. RESULTS: LVI by hematoxylin-eosin staining (HES) and IHCS were all negative in the absolute group, while was observed in only the expanded groups. The positive rate of LVI by IHCS was higher than that of LVI by HES (n = 1, 0.4% vs n = 11, 4.4%, P = 0.044). LVI IHCS-positivity was observed when the cancer invaded to the mucosa 3 (M3) or submucosa 1 (SM1) levels, with a predominance of 63.6% in the subgroup that included only SM1 cancer (P < 0.01). In a univariate analysis, M3 or SM1 invasion by the tumor was significantly associated with a higher rate of LVI by IHCS, but no factor was significant in a multivariate analysis. There were no cases of tumor recurrence or metastasis during the median 26 mo follow-up. CONCLUSION: EGCs of the absolute group are immunohistochemically stable. The presence of LVI may be carefully examined by IHCS in an ESD expanded indication group with an invasion depth of M3 or greater.

Two Cases of Adrenal Abscesses Following Histoacryl® (N-butyl-2-cyanocrylate) Injection.

We report two cases of adrenal abscesses that occurred following a Histoacryl® (N-butyl-2-cyanocrylate) injection for variceal bleeding. Patients had been diagnosed with alcoholic liver cirrhosis and gastric varices bleeding and received a Histoacryl® injection for the variceal bleeding. Patients had fever and abdominal tenderness and were diagnosed with an adrenal abscess at 2 months following the Histoacryl® injection. One patient received open drainage and the other underwent percutaneous drainage. When a patient has previously been injected with Histoacryl® for the treatment of variceal bleeding and presents with fever, an evaluation for an unusual complication such as adrenal abscess is recommended.

A novel device for endoscopic submucosal dissection, the Fork knife.

AIM: To introduce and evaluate the efficacy and technical aspects of endoscopic submucosal dissection (ESD) using a novel device, the Fork knife. METHODS: From March 2004 to April 2008, ESD was performed on 265 gastric lesions using a Fork knife (Endo FS) (group A) and on 72 gastric lesions using a Flexknife (group B) at a single tertiary referral center. We retrospectively compared the endoscopic characteristics of the tumors, pathological findings, and sizes of the resected specimens. We also compared the en bloc resection rate, complete resection rate, complications, and procedure time between the two groups. RESULTS: The mean size of the resected specimens was 4.27 +/- 1.26 cm in group A and 4.29 +/- 1.48 cm in group B. The en bloc resection rate was 95.8% (254/265 lesions) in group A and 93.1% (67/72) in group B. Complete ESD without tumor cell invasion of the resected margin was obtained in 81.1% (215/265) of group A and in 73.6% (53/72) of group B. The perforation rate was 0.8% (2/265) in group A and 1.4% (1/72) in group B. The mean procedure time was 59.63 +/- 56.12 min in group A and 76.65 +/- 70.75 min in group B (P < 0.05). CONCLUSION: The Fork knife (Endo FS) is useful for clinical practice and has the advantage of reducing the procedure time.

Cigarette smoking-induced acute eosinophilic pneumonia: a case report including a provocation test.

The mechanism and cause of acute eosinophilic pneumonia are largely unknown. Many factors including the smoking of cigarettes have been suggested, but none have been proven to directly cause acute eosinophilic pneumonia. The authors report a case of acute eosinophilic pneumonia in a young Asian male who recently started smoking. The diagnosis was made based on his clinical course and results of chest radiography, lung spirometry, bronchoalveolar lavage, and transbronchial lung biopsies. After administration of methylprednisolone, his clinical course rapidly improved. A provocation test was designed to establish a connection between cigarette smoking and the development of acute eosinophilic pneumonia. After the provocation test, the patient showed identical symptoms, increase in sputum eosinophils, and worsening of pulmonary function. The results of the provocation test suggest that smoking may directly cause acute eosinophilic pneumonia, and support previous reports of cigarette smoking-induced acute eosinophilic pneumonia.