Kyoo Wan Choi

Clinical usefulness of carbohydrate antigen 19-9 as a screening test for pancreatic cancer in an asymptomatic population.

Background and Aim:  Although the prognosis for pancreatic cancer is generally poor, it is well known that the survival rate for resected pancreatic cancer is much higher than that for more conservative treatment. The importance of early detection is emphasized for resection of pancreatic cancer. Measurement of serum carbohydrate antigen (CA) 19‐9 has shown satisfactory sensitivity and predictive value in symptomatic patients, but no available data has been found on healthy asymptomatic subjects. Thus, the authors aimed to determine the clinical usefulness of CA 19‐9 as a screening tool for pancreatic cancer in asymptomatic subjects.

Seroepidemiological study of Helicobacter pylori infection in asymptomatic people in South Korea

Abstract Background: Helicobacter pylori infection occurs throughout the world and causes gastroduodenal diseases in all age groups. The prevalence of H. pylori infection varies between countries and races. The aim of this study was to evaluate the seroprevalence of H. pylori infection in asymptomatic healthy people in South Korea.

Risk of gastric cancer among Korean familial adenomatous polyposis patients : report of three cases

Gastric cancer has been recognized as an extracolonic manifestation in patients with familial adenomatous polyposis (FAP). In Korea, gastric cancer is the most common malignant neoplasm. In a recent survey, we collected data from 72 Korean patients with FAP. Among them, three (4.2 percent) were found to have associated gastric cancer. This incidence of gastric cancer in our series is much higher than the previous reports from Japan and other countries. The expected cumulative incidence of gastric cancer among these 72 patients was 0.44, which gives the standardized incidence ratio of 6.9 (95 percent CI, 1.4–20.1). This difference in incidence of gastric cancer was statistically significant (P< 0.05), which implies that patients with FAP are at significantly higher risk of developing gastric cancer compared with the general population in Korea. These findings confirm an increased risk of gastric cancer in FAP patients, even in a region where gastric cancer is highly prevalent.

Managing anticoagulation and antiplatelet medications in GI endoscopy: a survey comparing the East and the West

BACKGROUND Anticoagulation and antiplatelet medications may potentiate GI bleeding, and their use may lead to an increased need for a GI endoscopy. We hypothesized that there might be different practice patterns among international endoscopists. OBJECTIVE To explore the differences in management practices for patients who receive anticoagulation and antiplatelet medications from Eastern and Western endoscopists. DESIGN International survey study. SETTING Academic medical centers and private clinics. SUBJECTS Members of the American Society for Gastrointestinal Endoscopy (ASGE) in Eastern (Korea, Japan, China, India, Thailand, Singapore, Malaysia, and Philippines) and Western (United States and Canada) countries were invited to complete a Web-site-based questionnaire. In addition, the questionnaire was sent to university hospitals in South Korea and academic institutions in the United States. METHODS A survey was administered that contained detailed questions about the use of an endoscopy in patients on anticoagulation and antiplatelet medications. MAIN OUTCOME MEASUREMENTS Different opinions and clinical practice patterns regarding the use of anticoagulation and antiplatelet medications by Eastern and Western endoscopists. RESULTS A total of 105 Eastern and 106 Western endoscopists completed the survey. Western endoscopists experienced more instances of procedure-related bleeding (P = .003) and thromboembolism after withdrawal of medications (P = .016). Eastern endoscopists restarted medications later (1-3 days) than Western endoscopists after a biopsy (same day) (P < .001). Eastern endoscopists withdrew aspirin for more than 7 days before a polypectomy and then restarted it 1 to 3 days after a polypectomy, whereas Western endoscopists performed a polypectomy without withdrawing aspirin (P < .001). ASGE guidelines were followed less often by Eastern than by Western endoscopists (P < .001). LIMITATIONS Low response rate, heterogeneity of the sample, and recall bias. CONCLUSIONS The opinions and clinical practice patterns for the management of anticoagulation and antiplatelet medications differed significantly between Eastern and Western endoscopists. The lack of uniformity in practice patterns suggests that more data and better education are required in the area of GI endoscopy for patients on anticoagulation and antiplatelet medications, particularly given that individual patient characteristics may be associated with unique types of complications.

Lack of association of Helicobacter pylori infection with gastric hypersensitivity or delayed gastric emptying in functional dyspepsia

Objective:We evaluated the relationship between Helicobacter pylori (H. pylori) infection and gastric sensitivity to distention or gastric emptying rate to define the role of H. pylori in the pathogenesis of functional dyspepsia.Methods:Gastric barostat, gastric emptying scintigraphy, and 13C urea breath test were performed in 34 consecutive patients with functional dyspepsia.Results:Between H. pylori-positive and -negative patients with functional dyspepsia, there were no significant differences in basal tone (57.2 ± 15.0 ml vs 66.8 ± 18.3 ml), compliance (41.0 ± 11.2 ml/mm Hg vs 38.2 ± 11.8 ml/mm Hg), threshold of first sense (3.6 ± 2.7 mm Hg vs 2.3 ± 1.5 mm Hg), threshold of abdominal discomfort (9.4 ± 4.0 mm Hg vs 7.3 ± 1.9 mm Hg), and postprandial receptive relaxation (115.4 ± 89.7 ml vs 99.0 ± 88.7 ml), measured by gastric barostat. Half gastric emptying time (88.6 ± 24.5 min vs 91.4 ± 21.6 min) and retention rate at 120 min (32.8 ± 17.8%vs 41.9 ± 20.1%) were also similar between the two groups.Conclusion:H. pylori infection was not associated with gastric hypersensitivity to distention or delayed gastric emptying.

Clinical diagnosis of primary epiploic appendagitis: Differentiation from acute diverticulitis

Background Primary epiploic appendagitis (PEA) is an uncommon cause of abdominal pain that occurs either from appendageal torsion or spontaneous thrombosis of an appendageal draining vein. Primary epiploic appendagitis is frequently misdiagnosed as either appendicitis or diverticulitis, depending on its location. Study Clinical and radiologic characteristics of 8 patients with PEA were retrospectively reviewed and compared with 18 patients with acute diverticulitis. Results Patients with PEA presented with lower abdominal pain of recent onset that was localized to the left (seven cases) and right (one case) lower quadrants. Well-localized tenderness without peritoneal irritation sign was usually the only physical finding. Blood tests were not significant. In acute diverticulitis, the pain was more evenly distributed throughout the lower abdomen and findings like nausea, fever, and leukocytosis were more frequently associated than in PEA. Computed tomography findings, such as pedunculated oval fatty mass with streaky densities connected to the serosal surface of the adjacent colon, can lead to the diagnosis of PEA. Symptoms of PEA were resolved within 1 week (mean, 4.7 days) without surgery. Conclusions When patients with very localized lower abdominal pain and tenderness do not have associated symptoms or laboratory abnormalities, a high index of suspicion for PEA and early radiologic examinations are required.

Evaluation of individual symptoms cannot predict presence of gastric hypersensitivity in functional dyspepsia

Recently, the concept of gastric hypersensitivity was introduced as an important factor in the pathophysiology of functional dyspepsia (FD), but it is unclear which symptoms can predict the presence of gastric hypersensitivity. Therefore, we evaluated the relationship between common symptoms of FD and various parameters measured by gastric barostat in FD patients. Gastric barostat tests were performed in 64 FD patients and 20 healthy control subjects without gastrointestinal symptoms. Individual symptoms such as early satiety, postprandial fullness, sense of delayed emptying, nausea, vomiting, and epigastric soreness were collected and graded as mild to severe. Basal tone, gastric compliance, and postprandial receptive relaxation were similar in controls and patients, the threshold of abdominal discomfort was lower in FD patients than in controls (8.9 ± 3.6 mm Hg and 14.5 ± 3.7 mm Hg, respectively, P < 0.05). However, there were no significant differences in the threshold of abdominal discomfort according to the severity of individual symptoms. In conclusion, a simple evaluation of individual symptoms could not predict the presence of gastric hypersensitivity.

The effect of sildenafil on lower esophageal sphincter and body motility in normal male adults

OBJECTIVE:Sildenafil relaxes smooth muscle by blocking type 5 phosphodiesterase, which destroys nitric oxide-stimulated cyclic guanosine monophosphate. The aim of this study is to investigate the change of lower esophageal sphincter (LES) and body motility with the lapse of time after sildenafil infusion in normal male adults.METHODS:After basal esophageal manometry in eight healthy male adult volunteers, we infused a 50-mg tablet of sildenafil dissolved in water in the stomach through the manometry catheter and observed the changes of LES and body motility with the lapse of time. We randomized the study population into two groups, and esophageal manometry was repeated in LES and body sequence in four volunteers and in body and LES sequence in the other four volunteers immediately after sildenafil infusion.RESULTS:LES resting pressure significantly decreased after sildenafil infusion. The body peristaltic amplitude gradually decreased and eventually disappeared, and the latency increased significantly after sildenafil infusion in both the proximal and distal esophagus.CONCLUSIONS:These data support that nitric oxide mediates LES relaxation and the timing of esophageal peristalsis. In the future, sildenafil can be tried in some esophageal motor disorders, which have defects in nitric oxide neuromuscular communication.

Interaction between cyclooxygenase-2 and inducible nitric oxide synthase in gastric cancer.

Background Chronic expression of cylcooygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) may play an important role in gastric carcinogenesis. Thus, the purpose of our study was to assess the expression of COX-2 and iNOS messenger RNA (mRNA) in gastric cancer and to investigate the correlation between the expression of COX-2 and iNOS mRNA in these patients. Study Twenty-three gastric carcinoma specimens and accompanying adjacent specimens were obtained from surgical resection. The expression of COX-2 and iNOS were examined by comparative reverse transcription polymerase chain reaction. Results Cylcooygenase-2 and iNOS mRNA were significantly higher in gastric cancer tissues than in adjacent normal tissues. There was significant correlation between the levels of COX-2 and iNOS mRNA in carcinoma tissues. However, there was no significant correlation between the level of COX-2 or iNOS mRNA expression and several clinicopathologic parameters in these patients. Conclusion The expression of COX-2 and iNOS may be one of the factors that contribute to gastric carcinogenesis.

Evaluation of Bone Metastases by Tc-99m MDP Imaging in Patients With Stomach Cancer

The authors conducted a retrospective review of 234 bone scans of stomach cancer patients who had been diagnosed at the Seoul National University Hospital. In 106 of the 234 cases (45.3%), there were abnormal bone scan results, suggestive of bone metastases. The most common site of bone metastases was the spine, followed by the ribs, pelvis, femur, and skull. These sites were similar to those known for other malignant diseases. The incidence of bone metastases increased according to the duration of disease, especially within 12 months after diagnosis in patients with stage III gastric cancer. The incidence of bone metastases increased as the clinical stage increased. However, the incidence of metastases did not relate to gastric cancer pathologic type. The authors found 6 cases of “superscan” In the 234 bone scans (2.6%). The bone scan findings correlated positively with the level of serum alkaline phosphatase.