Purpose: To compare encrustation resistance between silicon- and polytetrafluoroethylene (PTFE)-covered metallic ureteral stents (MUS) in an in vitro infection model and to determine the most effective material for reducing biofilm formation and encrustation. Materials and Methods: A total of 52 MUS were prepared: 26 silicon-covered and 26 PTFE-covered stents. Each sample was immersed in artificial urine inoculated with Proteus mirabilis in a biofilm reactor for 48 hours. After immersion, the stents were weighed to measure their encrustation level. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to assess the surface morphology and elemental composition of the encrustation deposits. Results: Silicon-covered stents showed a statistically significant reduction in weight gain due to encrustation compared to PTFE-co­vered stents (9.50±5.77 mg vs. 16.75±10.61 mg; p=0.004). Additionally, encrustation per unit length was lower in silicon-covered stents (0.76±0.45 mg/mm vs. 1.30±0.81 mg/mm; p=0.004). SEM and EDS analyses demonstrated lower calcium salt deposition on the silicon-co­vered stents, indicating greater resistance to encrustation. Conclusions Silicon-covered MUS demonstrated superior resistance to encrustation compared to PTFE-covered stents, supporting silicon as a more suitable covering material for long-term MUS applications. This finding may lead to extended stent lifespans and a reduced frequency of stent replacements, benefiting both patients and healthcare systems.

Retrorectal tumors, although rare, pose diagnostic and treatment challenges due to their nonspecific symptoms and complex anatomical location. This single-center case series reports short-term outcomes of laparoscopic transabdominal resection as a surgical approach for large retrorectal tumors. Between 2017 and 2020, five patients underwent this procedure. The median patient age was 53.2 years (range, 34–60 years), and the median operating time was 130 minutes (range, 95–205 minutes). All tumors were located in the retrorectal space. The median tumor size was 5.8 × 4.3 cm (range, 3.5–7.5 cm). Biopsy results included epidermoid cysts, tailgut cyst, lipoma, and keratinous cyst. The median hospital stay was 7.8 days (range, 5–11 days), and the median follow-up duration was 78.0 days (range, 14–219 days). One patient developed a postoperative surgical site infection. Overall, laparoscopic transabdominal resection appears to be a minimally invasive and effective treatment option for retrorectal tumors.

Retrorectal tumors, although rare, pose diagnostic and treatment challenges due to their nonspecific symptoms and complex anatomical location. This single-center case series reports short-term outcomes of laparoscopic transabdominal resection as a surgical approach for large retrorectal tumors. Between 2017 and 2020, five patients underwent this procedure. The median patient age was 53.2 years (range, 34–60 years), and the median operating time was 130 minutes (range, 95–205 minutes). All tumors were located in the retrorectal space. The median tumor size was 5.8 × 4.3 cm (range, 3.5–7.5 cm). Biopsy results included epidermoid cysts, tailgut cyst, lipoma, and keratinous cyst. The median hospital stay was 7.8 days (range, 5–11 days), and the median follow-up duration was 78.0 days (range, 14–219 days). One patient developed a postoperative surgical site infection. Overall, laparoscopic transabdominal resection appears to be a minimally invasive and effective treatment option for retrorectal tumors.

Retrorectal tumors, although rare, pose diagnostic and treatment challenges due to their nonspecific symptoms and complex anatomical location. This single-center case series reports short-term outcomes of laparoscopic transabdominal resection as a surgical approach for large retrorectal tumors. Between 2017 and 2020, five patients underwent this procedure. The median patient age was 53.2 years (range, 34–60 years), and the median operating time was 130 minutes (range, 95–205 minutes). All tumors were located in the retrorectal space. The median tumor size was 5.8 × 4.3 cm (range, 3.5–7.5 cm). Biopsy results included epidermoid cysts, tailgut cyst, lipoma, and keratinous cyst. The median hospital stay was 7.8 days (range, 5–11 days), and the median follow-up duration was 78.0 days (range, 14–219 days). One patient developed a postoperative surgical site infection. Overall, laparoscopic transabdominal resection appears to be a minimally invasive and effective treatment option for retrorectal tumors.

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Objective: Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. Methods: Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. Results: Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. Conclusion This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.

Purpose: Rectal prolapse is a benign disease in which the rectum protrudes below the anus. Although many studies have been reported on the treatment of primary rectal prolapse for many years, there is a lack of treatment or clinical research results on recurrent rectal prolapse. This study aimed to evaluate the outcomes of surgical approaches for recurrent rectal prolapse. Methods: We studied patients who underwent surgical treatment for recurrent rectal prolapse disease from March 2016 to February 2021. We analyzed the previous operation methods in patients with recurrent rectal prolapse, as well as the operation time, complication rate, hospital stay, and re-recurrence rates in the perineal and abdominal approach groups. Results: Out of a total of 239 patients, 41 patients who underwent surgery for recurrent rectal prolapse were retrospectively enrolled. Recurrent rectal prolapses were surgically treated either by the perineal approach (n = 25, 61.0%) or by the abdominal approach (n = 16, 39.0%). The operation times were significantly longer in the abdominal approach than in the perineal approach (98.44 minutes vs. 58.00 minutes, P = 0.001). Hospital stay was significantly longer in the abdominal approach than in the perineal approach (9.19 days vs. 6.00 days, P = 0.012). Re-recurrence rate after repeat repair was not significantly different between the 2 groups (P = 0.777). Conclusion Although the perineal approach shortened the operation time and hospital stay, there were no significant differences between the 2 groups in postoperative complications and re-recurrence rate. Both approaches can be good surgical options for the treatment of recurrent rectal prolapse.

Purpose: Diffuse large B-cell lymphoma (DLBCL) is the most common hematologic malignancy worldwide. Although substantial improvement has been achieved by the frontline rituximab-based chemoimmunotherapy, up to 40%-50% of patients will eventually have relapsed or refractory disease, whose prognosis is extremely dismal. Materials and Methods: We have carried out two prospective cohort studies that include over 1,500 DLBCL patients treated with rituximab plus CHOP (#NCT01202448 and #NCT02474550). In the current report, we describe the outcomes of refractory DLBCL patients. Patients were defined to have refractory DLBCL if they met one of the followings, not achieving at least partial response after 4 or more cycles of R-CHOP; not achieving at least partial response after 2 or more cycles of salvage therapy; progressive disease within 12 months after autologous stem cell transplantation. Results: Among 1,581 patients, a total of 260 patients met the criteria for the refractory disease after a median time to progression of 9.1 months. The objective response rate of salvage treatment was 26.4%, and the complete response rate was 9.6%. The median overall survival (OS) was 7.5 months (95% confidence interval, 6.4 to 8.6), and the 2-year survival rate was 22.1%±2.8%. The median OS for each refractory category was not significantly different (p=0.529). Conclusion In line with the previous studies, the outcomes of refractory DLBCL patients were extremely poor, which necessitates novel approaches for this population.

Purpose: Febrile neutropenia (FN) can cause suboptimal treatment and treatment-related mortality (TRM) in diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). Materials and methods: We conducted a prospective cohort study to evaluate the effectiveness of pegfilgrastim prophylaxis in DLBCL patients receiving R-CHOP, and we compared them with the PROCESS cohort (n=485). Results: Since January 2015, 986 patients with DLBCL were enrolled. Pegfilgrastim was administered at least once in 930 patients (94.3%), covering 90.3% of all cycles. FN developed in 137 patients (13.9%) in this cohort (23.7% in the PROCESS cohort, p<0.001), and 4.2% of all cycles (10.2% in the PROCESS cohort, p<0.001). Dose delay was less common (≥3 days: 18.1% vs. 23.7%, p=0.015; ≥5 days: 12.0% vs. 18.3%, p=0.023) in this cohort than in the PROCESS cohort. The incidence of TRM (3.2% vs. 5.6%, p=0.047) and infection-related death (1.8% vs. 4.5%, p=0.004) was lower in this cohort than in the PROCESS cohort. The 4-year overall survival (OS) and progression-free survival (PFS) rates of the two cohorts were not different (OS: 73.0% vs. 71.9%, p=0.545; PFS: 69.5% vs. 68.8%, p=0.616). However, in patients aged ≥75 years, the 4-year OS and PFS rates were higher in this cohort than in the PROCESS cohort (OS: 49.6% vs. 33.7%, p=0.032; PFS: 44.2% vs. 30.3% p=0.047). Conclusion Pegfilgrastim prophylaxis is effective in the prevention of FN and infection-related death in DLBCL patients receiving R-CHOP, and it also improves OS in patients aged ≥75 years.

Background/Aims: The adenoma detection rate (ADR) does not reflect the complete detection of every adenoma during colonoscopy; thus, many surrogate indicators have been suggested.This study investigated whether the ADR and surrogate quality indicators reflect the adenoma miss rate (AMR) when performing qualified colonoscopy. Methods: We performed a prospective, multicenter, cross-sectional study of asymptomatic examinees aged 50 to 75 years who underwent back-to-back screening colonoscopies by eight endoscopists. The ADR and surrogate quality indicators, including polyp detection rate, total number of adenomas per colonoscopy, additional adenomas found after the first adenoma per colonoscopy (ADR-Plus), and total number of adenomas per positive participant, were calculated for the prediction of AMR. Results: A total of 371 back-to-back colonoscopies were performed. There was a significant difference in ADRs (range, 44% to 75.4%; p=0.024), polyp detection rates (range, 56% to 86.9%; p=0.008) and adenomas per positive participants (range, 1.19 to 2.30; p=0.038), and a tendency of a difference in adenomas per colonoscopy (range, 0.62 to 1.31; p=0.051) and ADR-Plus (range, 0.13 to 0.70; p=0.054) among the endoscopists. The overall AMR was 20.1%, and AMRs were not different (range, 13.9 to 28.6; p>0.05) among the endoscopists. No quality indicators were significantly correlated with AMR. The number of adenomas found during the first colonoscopy was an independent factor for increased AMR (odds ratio, 1.79; p<0.001). Conclusions The colonoscopy quality indicators were significantly different among high-ADR endoscopists, and none of the quality indicators reflected the AMR of good quality colonoscopy performances. The only factor influencing AMR was the number of adenomas detected during colonoscopy.