Concurrent laparoscopic highly selective vagotomy with closure of duodenal ulcer perforations show good clinical results as primary repair alone.

OBJECTIVE: To compare clinical and operative results between laparoscopic primary repair (LPR) alone and LPR with highly selective vagotomy (LPR-HSV) in patients with duodenal ulcer perforation. METHODS: Clinical data from patients who underwent either LPR or LPR-HSV by resecting both sides of the neurovascular bundle using an ultrasonic or bipolar electrosurgical device for duodenal ulcer perforations, between 2010 and 2020, were retrospectively collected. Between-group differences in continuous and categorical variables were statistically analysed. RESULTS: Data from 184 patients (mean age, 49.6 years), who underwent either LPR (n = 132) or LPR-HSV (n = 52) were included. The mean operation time was significantly longer in the LPR-HSV group (116.5 ± 39.8 min) than in the LPR group (91.2 ± 33.3 min). Hospital stay was significantly shorter in the LPR-HSV group (8.6 ± 2.6 days) versus the LPR group (11.3 ± 7.1 days). The mean postoperative day of starting soft fluid diet was also significantly shorter in the LPR-HSV group (4.5 ± 1.4 days) than in the LPR group (5.6 ± 4 days). No between-group difference in morbidity rate was observed. The learning curve of the HSV procedure showed a stable procedure time after 10 operations. CONCLUSIONS: LPR with HSV may be a safe and feasible procedure for selective cases who are at high risk for ulcer recurrence.

Deep focus light-field camera for handheld 3D intraoral scanning using crosstalk-free solid immersion microlens arrays.

3D in vivo imaging techniques facilitate disease tracking and treatment, but bulky configurations and motion artifacts limit practical clinical applications. Compact light-field cameras with microlens arrays offer a feasible option for rapid volumetric imaging, yet their utilization in clinical practice necessitates an increased depth-of-field for handheld operation. Here, we report deep focus light-field camera (DF-LFC) with crosstalk-free solid immersion microlens arrays (siMLAs), allowing large depth-of-field and high-resolution imaging for handheld 3D intraoral scanning. The siMLAs consist of thin PDMS-coated microlens arrays and a metal-insulator-metal absorber to extend the focal length with low optical crosstalk and specular reflection. The experimental results show that the immersion of MLAs in PDMS increases the focal length by a factor of 2.7 and the transmittance by 5.6%-27%. Unlike conventional MLAs, the siMLAs exhibit exceptionally high f-numbers up to f/6, resulting in a large depth-of-field for light-field imaging. The siMLAs were fully integrated into an intraoral scanner to reconstruct a 3D dental phantom with a distance measurement error of 82 ± 41 µm during handheld operation. The DF-LFC offers a new direction not only for digital dental impressions with high accuracy, simplified workflow, reduced waste, and digital compatibility but also for assorted clinical endoscopy and microscopy.

Erratum: Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach.

This corrects the article on p. 3 in vol. 23, PMID: 36750993.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach.

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Korean practice guidelines for gastric cancer 2022: an evidence-based, multidisciplinary approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Ultra-wideband transmission filter based on guided-mode resonances in two terahertz metasurfaces.

This paper reports on a broadband transmission filter that employs the guided mode resonances pertaining to a terahertz metasurface composed of metallic gold disks with a quartz slab. Unlike structures involving conventional metasurfaces, two identical metasurfaces are placed on the upper and lower sides of a thick quartz slab. This structure can excite both even and odd guided mode resonances. The interaction of the two resonances at similar frequencies produces a broadband transmission peak. The sharp spectral feature of each resonance leads to the abrupt degradation of the transmission at the spectral edge, which can enable the development of the filter application. The proposed scheme can facilitate practical applications such as those of broadband filters at a terahertz frequency.

PHLPP1 Overexpression was Associated With a Good Prognosis With Decreased AKT Activity in Gastric Cancer.

Introduction: The aim of this study was to perform a clinicopathologic analysis of PHLPP1 expression in gastric cancer patients and analyze AKT activity with chemotherapy drug treatment in cancer subtypes. Materials and Methods: Surgically resected gastric cancer tissue specimens were obtained from 309 patients who underwent gastrectomy, and PHLPP1 expression was validated by tissue microarray analysis with immunohistochemistry. We assessed whether PHLPP1 selectively dephosphorylates Ser473 of AKT in an in-vitro study. Results: We found that the PHLPP1 overexpression (OE) group showed significantly greater proportions of differentiated subtype samples and early T stage samples, lower lymph node metastasis, and lower TNM stage than the PHLPP1 underexpression (UE) group. The overall survival of the PHLPP1-OE group was significantly higher (53.39 ± 0.96 months) than that of the PHLPP1-UE group (47.82 ± 2.57 months) (P = .01). In vitro analysis, we found that the PHLPP1-OE group showed a significant decrease in relative AKT S-473 levels in both cell lines (MKN-74 and KATO-III). We found that treatment with chemotherapy drugs decreased the activity of Ser473 in the MKN-74 cell line with PHLPP1 OE, but it did not affect the activity of Ser473 in KATO-III cells. Conclusion: We found that patients who overexpressed PHLPP1 showed low recurrence and good prognosis. PHLPP1 was found to work by lowering the activity of AKT Ser473 in gastric cancer. Additionally, we found a clue regarding the mechanism of chemotherapeutic drug resistance in a cell line of signet ring cell origin and will uncover this mechanism in the future.

Prevention of Petersen's hernia using jejunal mesentery fixing (Mefix).

BACKGROUND: The aim of this study was to compare the 1 year incidence of Petersen's hernia between individuals who were treated with the jejunal mesentery fixing (Mefix) method and those with the closure of Petersen's space method. MATERIAL AND METHODS: We retrospectively collected clinical data of patients who underwent gastrectomy for gastric cancers with the closure of Petersen's space defect (N = 49) and Mefix (N = 26). The Mefix method was performed by fixing the jejunal mesentery (jejunojejunostomy below 30 cm) to the transverse mesocolon using nonabsorbable barbed sutures. RESULTS: The procedure time for mesentery fixing (3.7 ± 1.1 mins) was significantly shorter than that for Petersen's space closure (7.5 ± 1.5 mins) (p < .001) although the operation times were similar between the two groups. There was no incidence of Petersen's hernias postoperatively in both groups. One case of reoperation was reported in the closure group due to small bowel obstruction by kinking of the jejunojejunostomy. CONCLUSION: We found no occurrence of Petersen's hernias postoperatively in either group. We also found that the Mefix method was faster and easier to perform than the closure method. The Mefix method is an excellent alternative method to prevent the occurrence of Petersen's hernia after B-II or Roux-en-Y reconstruction.

Multi-Focus Image Fusion Using Focal Area Extraction in a Large Quantity of Microscopic Images.

The non-invasive examination of conjunctival goblet cells using a microscope is a novel procedure for the diagnosis of ocular surface diseases. However, it is difficult to generate an all-in-focus image due to the curvature of the eyes and the limited focal depth of the microscope. The microscope acquires multiple images with the axial translation of focus, and the image stack must be processed. Thus, we propose a multi-focus image fusion method to generate an all-in-focus image from multiple microscopic images. First, a bandpass filter is applied to the source images and the focus areas are extracted using Laplacian transformation and thresholding with a morphological operation. Next, a self-adjusting guided filter is applied for the natural connections between local focus images. A window-size-updating method is adopted in the guided filter to reduce the number of parameters. This paper presents a novel algorithm that can operate for a large quantity of images (10 or more) and obtain an all-in-focus image. To quantitatively evaluate the proposed method, two different types of evaluation metrics are used: "full-reference" and "no-reference". The experimental results demonstrate that this algorithm is robust to noise and capable of preserving local focus information through focal area extraction. Additionally, the proposed method outperforms state-of-the-art approaches in terms of both visual effects and image quality assessments.

Prediction of the possibility of laparoscopic reduction of Petersen's hernia after gastrectomy: multicenter observational cohort study.

INTRODUCTION: Petersen's hernia (PH) is a potentially fatal complication of bowel infarction that is difficult to treat by laparoscopic reduction. AIM: To define predictive computed tomography (CT) profiles to identify PH patients who would be suitable for laparoscopic reduction by a comparative analysis between patients treated by laparoscopic and open reduction. MATERIAL AND METHODS: We retrospectively collected the clinical data of patients (n = 28) who underwent PH reduction surgery after minimally invasive gastrectomy for gastric cancer in the period 2015-2018 at four training hospitals. We examined the preoperative CT scans to identify the indications for laparoscopic PH reduction. RESULTS: We compared the laparoscopic reduction group (laparoscopic group, n = 15) and the open reduction group (open group, n = 13). Patients in the laparoscopic group were younger (55.7 ±10.4) than those in the open group (69.3 ±9.1), but there were no differences in clinical or laboratory findings. We found that there were two CT profiles with significant differences between the open and laparoscopic groups: superior mesenteric vein (SMV) narrowing and small bowel dilation. We found that small bowel dilatation was an independent factor on multivariate analysis for laparoscopic PH reduction. CONCLUSIONS: We found that small bowel dilatation is the most important CT profile for identifying PH patients contraindicated for laparoscopic reduction. Despite the retrospective design of this study, these CT profiles are expected to define the scope of laparoscopic reduction in PH patients and to establish indications for the laparoscopic approach.

Postoperative morbidity and quality of life between totally laparoscopic total gastrectomy and laparoscopy-assisted total gastrectomy: a propensity-score matched analysis.

BACKGROUND: This study aimed to evaluate the surgical outcome and quality of life (QoL) of totally laparoscopic total gastrectomy (TLTG) compared with laparoscopy-assisted total gastrectomy (LATG) in patients with clinical stage I gastric cancer. METHODS: From 2012 to 2018, EGC patients who underwent TLTG (n = 223), including the first case with intracorporeal hemi-double stapling, were matched to those who underwent LATG (n = 114) with extracorporeal circular stapling, using 2:1 propensity score matching (PSM). Prospectively collected morbidity was compared between the TLTG and LATG groups in conjunction with the learning curve. The European Organization for Research and Treatment of Cancer (EORTC) QoL questionnaires QLQ-C30, STO22, and OG25 were prospectively surveyed during postoperative 1 year for patient subgroups. RESULTS: After PSM, grade I pulmonary complication rate was lower in the TLTG group (n = 213) than in the LATG group (n = 111) (0.5% vs. 5.4%, P = 0.007). Other complications were not different between the groups. The learning curve of TLTG was overcome at the 26th case in terms of the comprehensive complication index. The TLTG group after learning curve showed lower grade I pulmonary complication rate than the matched LATG group (0.5% vs. 4.7%, P = 0.024). Regarding postoperative QoL, the TLTG group (n = 63) revealed less dysphagia (P = 0.028), pain (P = 0.028), eating restriction (P = 0.006), eating (P = 0.004), odynophagia (P = 0.023) than the LATG group (n = 21). Multivariate analyses for each QoL item demonstrated that TLTG was the only common independent factor for better QoL. CONCLUSIONS: TLTG reduced grade I pulmonary complications and provided better QoL in dysphagia, pain, eating, odynophagia than LATG for patients with clinical stage I gastric cancer.

A comparison of quality of life between patients with small and large gastric remnant volumes after gastrectomy for gastric cancer.

ABSTRACT: The impact of gastric remnant volumes (GRVs) after gastrectomy on patients' quality of life (QOL) has not yet been clarified. The aim of the present study was to compare QOL after gastrectomy between small and large gastric remnant volume patients.We prospectively collected clinical data from 78 consecutive patients who underwent distal gastrectomy with Billroth II gastrojejunostomy for gastric cancer. The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Stomach questionnaire and gastric computed tomography scans were performed. The patients were subdivided into 2 groups by remnant stomach volume (the S group ≤110 mL vs L group >110 mL).The worst scores for most items were observed at postoperative month 1 and usually improved thereafter. There was no difference in the STO22 score except for dysphagia between the S and L groups after gastrectomy (P > .05). The QOL score of dysphagia was different at postoperative 6 months (S vs L, 12.4 vs 22.8, P < .03), but there was no difference at postoperative months 1, 3, 12, 24, or 36 (P > .05).The remnant gastric volume after partial gastrectomy affects neither functional differences nor QOL after 6 months following appropriate radical surgery.

Transcriptome Analysis and the Prognostic Role of NUDC in Diffuse and Intestinal Gastric Cancer.

INTRODUCTION: There have been few studies about gene differences between patients with diffuse-type gastric cancer and those with intestinal-type gastric cancer. The aim of this study was to compare the transcriptomes of signet ring cell gastric cancer (worst prognosis in diffuse-type) and well-differentiated gastric cancer (best prognosis in intestinal-type); NUDC was identified, and its prognostic role was studied. MATERIALS AND METHODS: We performed next-generation sequencing with 5 well-differentiated gastric cancers and 3 of signet ring cell gastric cancer surgical samples. We performed gene enrichment and functional annotation analysis using the Database for Annotation, Visualization and Integrated Discovery bioinformatics resources. Immunohistochemistry was used to validate NUDC expression. RESULTS: Overall, 900 genes showed significantly higher expression, 644 genes showed lower expression in signet ring cell gastric cancer than in well-differentiated gastric cancers, and there was a large difference in adhesion, vascular development, and cell-to-cell junction components between the 2 subtypes. We performed variant analysis and found 52 variants and 30 cancer driver genes, including NUDC. We analyzed NUDC expression in gastric cancer tissue and its relationship with prognosis. Cox proportional hazard analysis identified T stage, N stage, and NUDC expression as independent risk factors for survival (P < 0.05). The overall survival of the NUDC-positive group was significantly higher (53.2 ± 0.92 months) than that of the NUDC-negative group (44.6 ± 3.7 months) (P = 0.001) in Kaplan-Meier survival analysis. CONCLUSION: We found 30 cancer driver gene candidates and found that the NUDC-positive group showed significantly better survival than the NUDC-negative group via variant analysis.

A comparison of postoperative outcomes after open and laparoscopic reduction of Petersen's Hernia: a multicenter observational cohort study.

BACKGROUND: The aim of this multicenter cohort study was to compare the clinical courses between open and laparoscopic Petersen's hernia (PH) reduction. METHOD: We retrospectively collected the clinical data of patients who underwent PH repair surgery after gastrectomy for gastric cancer from 2015-2018. Forty patients underwent PH reduction operations that were performed by six surgeons at four hospitals. Among the 40 patients, 15 underwent laparoscopic PH reduction (LPH), and 25 underwent open PH reduction (OPH), including 4 patients who underwent LPH but required conversion to OPH. RESULTS: We compared the clinical factors between the LPH and OPH groups. In the clinical course, we found no differences in operation times or intraoperative bowel injury, morbidity, or mortality rates between the two groups (p > 0.05). However, the number of days on a soft fluid diet (OPH vs. LPH; 5.8 vs. 3.7 days, p = 0.03) and length of hospital stay (12.6 vs. 8.2 days, p = 0.04) were significantly less in the LPH group than the OPH group. Regarding postoperative complications, the OPH group had a case of pneumonia and sepsis with multi-organ failure, which resulted in mortality. In the LPH group, one patient experienced recurrence and required reoperation for PH. CONCLUSION: Laparoscopic PH reduction was associated with a faster postoperative recovery period than open PH reduction, with a similar incidence of complications. The laparoscopic approach should be considered an appropriate strategy for PH reduction in selected cases.

Clinical Significance of Intra-operative Gastroscopy for Tumor Localization in Totally Laparoscopic Partial Gastrectomy.

BACKGROUND: Tumor localization during totally laparoscopic gastrectomy is challenging owing to the invisibility of tumors on the serosal surface. We aimed to evaluate the clinical significance of intra-operative gastroscopy in totally laparoscopic partial gastrectomy. METHODS: We reviewed 1084 gastric cancer patients who underwent either intra- or extracorporeal partial gastrectomy between 2014 and 2018. The intracorporeal group with intra-operative gastroscopy (intra-operative gastroscopy group, n = 187), the intracorporeal group without intra-operative gastroscopy (non-intra-operative gastroscopy group, n = 267), and the extracorporeal group (n = 630) were evaluated for the adequacy of surgical resection margins. We assessed whether total gastrectomy could be avoided according to the performance of intra-operative gastroscopy if the tumor was located within 3-5 cm away from the gastroesophageal junction. RESULTS: The proximal margin positivity was lesser in the intra-operative gastroscopy group than in the non-intra-operative gastroscopy group (0% versus 2.2%; P = 0.045) but similar to that in the extracorporeal group (0% versus 0.6%; P = 0.579). The number of cases with proximal resection margins < 1 cm was lower in the intra-operative gastroscopy group than in the non-intra-operative gastroscopy group (3.7% versus 9.4%; P = 0.025) but comparable with that in the extracorporeal group (3.7% versus 4.1%; P = 0.815). Among 94 patients with lesions located within 3-5 cm apart from the gastroesophageal junction, the intra-operative gastroscopy group (n = 47) had fewer patients who underwent total gastrectomy than the non-intra-operative gastroscopy group (n = 47) (12.8% versus 44.7%; P = 0.001). Intra-operative gastroscopy was the only independent factor that prevented total gastrectomy (P = 0.001). CONCLUSION: Intra-operative gastroscopy can provide margin safety during intracorporeal partial gastrectomy, avoiding unnecessary total gastrectomy.

Traumatic neuroma of remnant cystic duct mimicking duodenal subepithelial tumor: A case report.

BACKGROUND: Gastrointestinal subepithelial tumors (GSTs), incidentally detected during upper gastrointestinal (GI) endoscopy, may be lesions derived from the GI wall or may be caused by compression from external organs. In general, traumatic neuroma is a benign nerve tumor that results from postoperative nerve injury, occurring in the bile duct as one of the complications after cholecystectomy. This is the first case report demonstrating that neuroma of the cystic duct can be incorrectly perceived as a duodenal subepithelial tumor by compressing the duodenal wall. CASE SUMMARY: We report the case of a 72-year-old man with traumatic neuroma of the cystic duct after cholecystectomy. This tumor was mistaken for a duodenal subepithelial tumor on preoperative upper GI endoscopy and endoscopic ultrasonography due to external compression of the GI wall. The patient had no symptoms, and his laboratory test results were normal. However, in a series of follow-up endoscopies, the tumor was found to have grown in size, so it was surgically resected. The lesion was completely removed by laparoscopic endoscopic cooperative surgery. The patient was discharged on postoperative day 7 without complications. CONCLUSION: Traumatic neuroma of the cystic duct can be mistaken for GSTs in GI endoscopy.

Fluorescent stem peptide mimics: In situ probes for peptidoglycan crosslinking.

Understanding the mechanisms of bacterial cell wall synthesis is essential for microbiology and medicine alike. A key step in this process is peptidoglycan crosslinking, which confers mechanical strength to the cell wall and represents a target for numerous classes of antibiotics. However, the biology of crosslinking remains poorly understood due to a lack of tools for studying the reaction in vivo. Recently, we developed a class of synthetic probes called fluorescent stem peptide mimics (FSPMs) that meet this need, allowing quantification and localization of crosslinking activity in live bacteria. We have utilized FSPMs to describe novel aspects of peptidoglycan synthesis in the human pathogen, Staphylococcus aureus. To enable wider use of our methodology, we provide detailed protocols herein for the synthesis of FSPMs, labeling of live bacteria, and evaluation of crosslinking by flow cytometry and super-resolution microscopy. We believe that FSPMs, together with complementary biosynthetic probes and traditional bacteriologic methods, will help to advance our understanding of peptidoglycan biology and accelerate the search for new antibiotics.

PRDX4 overexpression is associated with poor prognosis in gastric cancer.

Peroxiredoxin IV (PRDX4) is a multifunctional protein that is involved in cell protection against oxidative injury, regulation of cell proliferation, modulation of intracellular signaling, and the pathogenesis of tumors. We previously conducted a proteomic analysis to investigate tumor-specific protein expression in gastric cancer. The aim of the present study was to investigate whether PRDX4 could be a marker of poor prognosis in patients with gastric cancer. Immunohistochemistry was used to validate PRDX4 as a prognostic marker for gastric cancer. Short hairpin RNA (shRNA)-mediated knockdown of PRDX4 expression in AGS cells and MKN28 cells was used for functional studies, and PRDX4 overexpression in PRDX4-depleted cells was used for knock-in studies. Based on immunohistochemistry data, TNM stage and PRDX4 were independent prognostic factors in the Cox proportional hazard model (P<0.05). In the survival analysis, the PRDX4-overexpressing group demonstrated significantly worse survival than the PRDX4-underexpression group (P<0.01). In vitro, knockdown of PRDX4 expression by shRNA caused a significant decrease in cancer invasion. Conversely, overexpression of PRDX4 in PRDX4-depleted cancer cells promoted migration and invasion. By measuring the expression of EMT-related genes, we found that E-cadherin was increased in shPRDX4 cells compared with control shMKN28 cells, and snail and slug were decreased in shPRDX4-1 cells compared with sh-control cells. Furthermore, the expression levels of these genes could be recovered in rescue experiments. In conclusion, the results of the present study suggested that PRDX4 is a marker of poor prognosis in gastric cancer and that PRDX4 is associated with cancer cell migration and invasion via EMT.