Hyeong Seok Nam

Current Status of Biliary Metal Stents.

Many advances have been achieved in biliary stenting over the past 30 years. Endoscopic stent placement has become the primary management therapy to relieve obstruction in patients with benign or malignant biliary tract diseases. Compared with plastic stents, a self-expandable metallic stent (SEMS) has been used for management in patients with malignant strictures because of a larger lumen and longer stent patency. Recently, SEMS has been used for various benign biliary strictures and leaks. In this article, we briefly review the characteristics of SEMS as well as complications of stent placement. We review the current guidelines for managing malignant and benign biliary obstructions. Recent developments in biliary stenting are also discussed.

Risk Factors of Submucosal or Lymphovascular Invasion in Early Gastric Cancer <2 cm.

AbstractAlthough prediction of submucosal (SM) or lymphovascular (LV) invasion is important before endoscopic resection of early gastric cancer (EGC), it can only be confirmed following endoscopic resection. After endoscopic resection, patients with SM or LV invasion may require additional surgery due to high risk of lymph node metastasis.We conducted a retrospective study to identify risk factors for SM or LV invasion before endoscopic submucosal dissection (ESD) of EGC. Between January 2009 and May 2014, we reviewed the data of patients with EGC who met the absolute indications for ESD before procedure: well and/or moderately differentiated adenocarcinomas, tumors ⩽ 2 cm in length and absence of ulcer or ulcer-scar.During study period, a total of 308 lesions in 297 patients were included. SM or LV invasion was detected in 34 lesions (34/308, 11.0%). Multivariate analysis revealed that a moderately differentiated adenocarcinoma (odds ratio [OR] 4.157, P = 0.000) and location of the stomach (the upper and middle third; OR 3.100, P = 0.008) were significant risk factors for SM or LV invasion.Careful consideration of endoscopic treatment decision might be necessary for the patients with a moderately differentiated adenocarcinoma and EGC located on the upper and middle third of the stomach.

Is endoscopic ultrasonography essential for endoscopic resection of small rectal neuroendocrine tumors

AIM To evaluate the importance of endoscopic ultrasonography (EUS) for small (≤ 10 mm) rectal neuroendocrine tumor (NET) treatment. METHODS Patients in whom rectal NETs were diagnosed by endoscopic resection (ER) at the Pusan National University Yangsan Hospital between 2008 and 2014 were included in this study. A total of 120 small rectal NETs in 118 patients were included in this study. Histologic features and clinical outcomes were analyzed, and the findings of endoscopy, EUS and histology were compared. RESULTS The size measured by endoscopy was not significantly different from that measured by EUS and histology (r = 0.914 and r = 0.727 respectively). Accuracy for the depth of invasion was 92.5% with EUS. No patients showed invasion of the muscularis propria or metastasis to the regional lymph nodes. All rectal NETs were classified as grade 1 and demonstrated an L-cell phenotype. Mean follow-up duration was 407.54 ± 374.16 d. No patients had local or distant metastasis during the follow-up periods. CONCLUSION EUS is not essential for ER in the patient with small rectal NETs because of the prominent morphology and benign behavior.

Correction: The Value of Computed Tomography in Preoperative N Staging of Early Gastric Cancer Meeting the Endoscopic Resection Criteria

This correction is being published to correct Fig. 2B in above article.

Factors associated with the efficacy of miniprobe endoscopic ultrasonography after conventional endoscopy for the prediction of invasion depth of early gastric cancer

Abstract Background: This study aimed to compare the accuracy of conventional endoscopy (CE) and endoscopic ultrasonography (EUS) to predict tumor invasion depth and to determine factors associated with higher accuracy of additional miniprobe EUS after CE. Methods: Between May 2009 and February 2015, 273 lesions in 266 patients were subjected to miniprobe EUS after CE and curative treatment for well-to-moderately differentiated early gastric cancer (EGC). We reviewed preoperative CE and EUS findings and compared them to the pathologic findings. Results: The accuracy of CE and EUS to estimate the invasion depth of EGCs was 78.8% (215/273) and 83.9% (229/273) (p = .124), respectively. Using multivariate analysis, irregular depressed surface (odds ratio [OR] 8.11; 95% confidence interval [CI]: 2.79–23.53), fold change (OR 7.22; 95% CI: 2.33–22.38), size >2 cm (OR 2.72; 95% CI: 1.15–6.42) and ulcer scar (OR 2.64; 95% CI: 1.07–6.49) were associated with the higher accuracy of EUS than that of CE. Conclusions: Routine assessment using miniprobe EUS did not increase the accuracy of predicting invasion depth, compared to CE. However, EUS could be helpful in the treatment decision-making process for EGCs with lesions having irregular surfaces, fold change, size >2 cm, or ulcer scar.

Assessment of disease activity by fecal immunochemical test in ulcerative colitis

AIM To evaluate the efficacy of quantitative fecal immunochemical test (FIT) as biomarker of disease activity in ulcerative colitis (UC). METHODS Between February 2013 and November 2014, a total of 82 FIT results, obtained in conjunction with colonoscopies, were retrospectivelyevaluated for 63 patients with UC. The efficacy of FIT for evaluation of disease activity was compared to colonoscopic findings. Quantitative fecal blood with automated equipment examined from collected feces. Endoscopic disease severity were assessed using the Mayo endoscopic subscore (MES) classification. The extent of disease were classified by proctitis (E1), left sided colitis (E2), and extensive colitis (E3). Clinical activity were subgrouped by remission or active. RESULTS All of 21 patients with MES 0 had negative FIT (< 7 ng/mL), but 22 patients with MES 2 or 3 had a mean FIT of > 134.89 ng/mL. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of negative FIT about mucosal healing were 73.33%, 81.82%, 91.49%, 51.43% and 73.17%, respectively. The sensitivity, specificity, PPV, NPV and accuracy of predictive value of positive FIT (cutoff value > 100 ng/mL) about active disease status were 45.45%, 93.33%, 71.43%, 82.35% and 26.83%, respectively. Among patients with clinical remission, FIT was negative in 31 (81.6%) of 38 cases, with a mean fecal hemoglobin concentration of 6.12 ng/mL (range, negative to 80.9 ng/mL) for this group of patients. Among patients with clinical active disease, FIT was negative in 16 (36.4%) out of 44 cases, with a mean fecal hemoglobin concentration > 167.4 ng/mL for this group of patients. FIT was positively correlated with endoscopic activity (r = 0.626, P < 0.01) and clinical activity (r = 0.496, P < 0.01). But, FIT did not correlate with the extent of disease (r = -0.047, P = 0.676) CONCLUSION Quantitative FIT can be a non-invasive and effective biomarker for evaluation of clinical and endoscopic activity in UC, but not predict the extent of disease.

Endoscopic Ultrasound-Guided Drainage without Fluoroscopic Guidance for Extraluminal Complicated Cysts

Background. Endoscopic ultrasound- (EUS-) guided drainage is generally performed under fluoroscopic guidance. However, improvements in endoscopic and EUS techniques and experience have led to questions regarding the usefulness of fluoroscopy. This study aimed to retrospectively evaluate the safety and efficacy of EUS-guided drainage of extraluminal complicated cysts without fluoroscopic guidance. Methods. Patients who had undergone nonfluoroscopic EUS-guided drainage of extraluminal complicated cysts were enrolled. Drainage was performed via a transgastric, transduodenal, or transrectal approach. Single or double 7 Fr double pigtail stents were inserted. Results. Seventeen procedures were performed in 15 patients in peripancreatic fluid collections (n = 13) and pelvic abscesses (n = 4). The median lesion size was 7.1 cm (range: 2.8–13.0 cm), and the mean time spent per procedure was 26.2 ± 9.8 minutes (range: 16–50 minutes). Endoscopic drainage was successful in 16 of 17 (94.1%) procedures. There were no complications. All patients experienced symptomatic improvement and revealed partial to complete resolution according to follow-up computed tomography findings. Two patients developed recurrent cysts that were drained during repeat procedures, with eventual complete resolution. Conclusion. EUS-guided drainage without fluoroscopic guidance is a technically feasible, safe, and effective procedure for the treatment of extraluminal complicated cysts.

Endoscopic predictive factors associated with local recurrence after gastric endoscopic submucosal dissection

Abstract Objective: Endoscopic submucosal dissection (ESD) has been accepted as the treatment of choice for gastric epithelial neoplasia. Endoscopic characteristics of the primary lesion and post-ESD scars may be informative to predict the possibility of local recurrence. Methods: Between November 2008 and July 2015, a retrospective study was conducted in a single-tertiary referral hospital. Consecutive patients who underwent ESD for early gastric cancer (EGC) or high-grade dysplasia were analyzed to evaluate the incidence of local recurrence and associated endoscopic characteristics. Results: A total of 639 lesions were analyzed. The rates of en-bloc and complete resection were 98.1% and 95.5%, respectively. A total of 15 local recurrent lesions were found (2.3%). The endoscopic findings of primary lesions associated with local recurrence were a lesion size ≥20 mm (odds ratio, OR, 4.408; 95% confidence interval, CI, 1.369–14.186, p = .013) and incomplete endoscopic resection (OR 17.059, 95% CI 4.887–59.551, p < .001). During follow-up endoscopic examinations, atypical scar findings (non-flat morphology, erythematous color change and uneven surface pattern) were significant endoscopic findings to predict local recurrence. Local recurrence was absent for ESD scars with even-flat morphology without erythema. Conclusion: Lesions with larger size (≥ 20 mm) and incompletely resected lesions had higher risk of local recurrence. Endoscopic forceps biopsy is unnecessary for even-flat ESD scar without erythematous changes.

Endoscopic submucosal dissection of gastric neoplasms using a snare tip

Abstract Background: Endoscopic submucosal dissection (ESD) enables the complete removal of gastric lesions regardless of tumor size. ESD is typically performed using one of several available electrocautery knives and endoscopic mucosal resection (EMR) is performed using a diathermic snare. We aimed to investigate the clinical outcomes and complications in patients in whom a snare tip was used for ESD. Materials and methods: We retrospectively evaluated the medical records of 30 patients who underwent removal of a gastric lesion using a snare tip by ESD or hybrid ESD (ESD with snaring). For hybrid ESD, snaring was performed after an adequate submucosal dissection. The clinical outcomes according to the endoscopic procedure performed were evaluated. Results: ESD was performed in 12 patients and hybrid ESD was performed in 26 patients. Overall en-bloc and complete resection rates were both 97.4%. There was one case where piece-meal resection was performed in the hybrid ESD group. There were no procedure related complications such as perforation or bleeding. The mean specimen size was 2.8 ± 0.6 cm in the ESD group and 2.3 ± 0.5 cm in the hybrid ESD group (p = .031). The mean procedure time did not differ between the two methods (12.8 min in ESD and 9.7 min in hybrid ESD, p = .060). Conclusions: The snare tip can be used as an electrocautery knife to incise the mucosa and dissect the submucosa during removal of a gastric lesion.

Preprocedural prediction of non-curative endoscopic submucosal dissection for early gastric cancer

Background and aim Endoscopic submucosal dissection (ESD) has been accepted as the treatment of choice for early gastric cancer (EGC) without lymph node metastasis. However, additional surgical gastrectomy should be considered after non-curative endoscopic resection. We aimed to evaluate the predictive factors associated with non-curative endoscopic resection. Methods Between November 2008 and June 2015, a retrospective study was conducted in a single, tertiary, referral hospital. A total of 596 EGC lesions resected by ESD were analyzed. Non-curative endoscopic resection was defined as the occurrence of lesions associated with piecemeal resection, positive resection margins, lymphovascular invasion, or lesions that did not meet the expanded indications for ESD. Results The rate of non-curative endoscopic resection was 16.1%. The mean follow-up period was 35.3 ± 25.0 months. Associated predictive factors for non-curative endoscopic resection were female sex (OR, 2.470; p = 0.004), lesion size ≥ 20 mm (OR 3.714; p < 0.001), longer procedure time (OR 2.449, p = 0.002), ulceration (OR 3.538, p = 0.002), nodularity (OR 2.967, p<0.001), depression (OR 1.806, p = 0.038), undifferentiated carcinoma (OR 2.825, p = 0.031) and lesion located in the mid or upper third of stomach (OR 7.135 and OR 4.155, p<0.001, respectively). As the number of risk factors increased, the risk of non-curative ESD also increased. Conclusions Prior to selection of ESD, the risks associated with non-curative ESD should be considered so that appropriate treatment modalities may be selected.