Restoring thalamocortical circuit dysfunction by correcting HCN channelopathy in Shank3 mutant mice.

Thalamocortical (TC) circuits are essential for sensory information processing. Clinical and preclinical studies of autism spectrum disorders (ASDs) have highlighted abnormal thalamic development and TC circuit dysfunction. However, mechanistic understanding of how TC dysfunction contributes to behavioral abnormalities in ASDs is limited. Here, our study on a Shank3 mouse model of ASD reveals TC neuron hyperexcitability with excessive burst firing and a temporal mismatch relationship with slow cortical rhythms during sleep. These TC electrophysiological alterations and the consequent sensory hypersensitivity and sleep fragmentation in Shank3 mutant mice are causally linked to HCN2 channelopathy. Restoring HCN2 function early in postnatal development via a viral approach or lamotrigine (LTG) ameliorates sensory and sleep problems. A retrospective case series also supports beneficial effects of LTG treatment on sensory behavior in ASD patients. Our study identifies a clinically relevant circuit mechanism and proposes a targeted molecular intervention for ASD-related behavioral impairments.

Comparison between the mesenteric fixation method (MEFIX) and conventional methods at preventing the occurrence of Petersen's hernia: a study protocol for a multicenter randomized controlled trial.

BACKGROUND: Petersen's hernia, which occurs after Billroth-II (B-II) or Roux-en-Y (REY) anastomosis, can be reduced by defect closure. This study aims to compare the incidence of bowel obstruction above Clavien-Dindo classification grade III due to Petersen's hernia between the mesenteric fixation method and the conventional methods after laparoscopic or robotic gastrectomy. METHODS: This study was designed as prospective, single-blind, non-inferiority randomized controlled multicenter trial in Korea. Patients with histologically diagnosed gastric cancer of clinical stages I, II, or III who underwent B-II or REY anastomosis after laparoscopic or robotic gastrectomy are enrolled in this study. Participants who meet the inclusion criteria are randomly assigned to two groups: a CLOSURE group that underwent conventional Petersen's defect closure method and a MEFIX group that underwent the mesenteric fixation method. The primary endpoint is the number of patients who underwent surgery for bowel obstruction caused by Petersen's hernia within 3 years after laparoscopic or robotic gastrectomy. DISCUSSION: This trial is expected to provide high-level evidence showing that the MEFIX method can quickly and easily close Petersen's defect without increased postoperative complications compared to the conventional method. TRIAL REGISTRATION: ClinicalTrials.gov NCT05105360. Registered on November 3, 2021.

Identifying the best candidates for reduced port gastrectomy.

BACKGROUND: Previous studies have focused on the non-inferiority of RPG compared with conventional port gastrectomy (CPG); however, we assumed that some candidates might derive more significant benefit from RPG over CPG. METHODS: We retrospectively analyzed the clinicopathological and perioperative parameters of 1442 patients with gastric cancer treated by gastrectomy between 2009 and 2022. The C-reactive protein level on postoperative day 3 (CRPD3) was used as a surrogate parameter for surgical trauma. Patients were grouped according to the extent of gastrectomy [subtotal gastrectomy (STG) or total gastrectomy (TG)] and lymph node dissection (D1+ or D2). The degree of surgical trauma, bowel recovery, and hospital stay between RPG and CPG was compared among those patient groups. RESULTS: Of 1442 patients, 889, 354, 129, and 70 were grouped as STGD1+, STGD2, TGD1+, and TGD2, respectively. Compared with CPG, RPG significantly decreased CRPD3 only among patients in the STGD1+ group (CPG: n = 653, 84.49 mg/L, 95% CI 80.53-88.45 vs. RPG: n = 236, 70.01 mg/L, 95% CI 63.92-76.09, P < 0.001). In addition, the RPG method significantly shortens bowel recovery and hospital stay in the STGD1+ (P < 0.001 and P < 0.001), STGD2 (P < 0.001 and P < 0.001), and TGD1+ (P = 0.026 and P = 0.007), respectively. No difference was observed in the TGD2 group (P = 0.313 and P = 0.740). CONCLUSIONS: The best candidates for RPG are patients who undergo STGD1+, followed by STGD2 and TG D1+, considering the reduction in CRPD3, bowel recovery, and hospital stay.

Clinical strategies for securing negative proximal margin in early gastric cancer.

Securing an appropriate proximal resection margin (PRM) is crucial for oncological safety in treating gastric cancer. This study investigated the clinicopathological characteristics of patients with incomplete PRM length of <2 cm in early gastric cancer. Clinicopathological data of 1,493 patients who underwent subtotal gastrectomy for early gastric cancer in 2012 to 2021 were retrospectively reviewed. Patients were divided into the PRM length of <2 cm and ≥2 cm groups based on pathological results. Univariate and multivariate analyses evaluated factors for incomplete PRM length. Factors related to patients with a relative PRM positive were also analyzed. The proportion of patients with a PRM length of <2 cm was 17.9% (267/1,493). Multivariate regression analysis revealed that age <50, preoperative endoscopic size of ≥3 cm, size discrepancy of ≥2 cm, and midbody tumor with a lesser curvature significantly contributed to the PRM length of <2 cm. Twenty-four patients had a relative PRM positive (24/1493, 1.6%). An incomplete PRM was the only risk factor for a positive relative PRM. Surgical treatment for early gastric cancer requires an accurate preoperative endoscopic tumor size and location evaluation. A more aggressive resection is recommended for patients with age <50, preoperative endoscopic size of ≥3 cm, size discrepancy of ≥2 cm, and midbody tumor with a lesser curvature.

Local Recurrence after Endoscopic Submucosal Dissection of Early Gastric Cancer.

Endoscopic submucosal dissection (ESD) is considered the treatment of choice for early gastric cancer (EGC) with a negligible risk of lymph node metastasis. Locally recurrent lesions on artificial ulcer scars are difficult to manage. Predicting the risk of local recurrence after ESD is important to manage and prevent the event. We aimed to elucidate the risk factors associated with local recurrence after ESD of EGC. Between November 2008 and February 2016, consecutive patients (n = 641; mean age, 69.3 ± 9.5 years; men, 77.2%) with EGC who underwent ESD at a single tertiary referral hospital were retrospectively analyzed to evaluate the incidence and factors associated with local recurrence. Local recurrence was defined as the development of neoplastic lesions at or adjacent to the site of the post-ESD scar. En bloc and complete resection rates were 97.8% and 93.6%, respectively. The local recurrence rate after ESD was 3.1%. The mean follow-up period after ESD was 50.7 ± 32.5 months. One case of gastric cancer-related death (0.15%) was noted, wherein the patient had refused additive surgical resection after ESD for EGC with lymphatic and deep submucosal invasion. Lesion size ≥15 mm, incomplete histologic resection, undifferentiated adenocarcinoma, scar, and the absence of erythema of the surface were associated with a higher risk of local recurrence. Predicting local recurrence during regular endoscopic surveillance after ESD is important, especially in patients with a larger lesion size (≥15 mm), incomplete histologic resection, surface changes of scars, and no erythema of the surface.

Application of the Falciform Ligament Patch for the Prevention of Duodenal Stump Leakage After Gastrectomy: Technical Report on a Case Series.

Background: Duodenal stump leakage (DSL) is a serious complication after gastrectomy. In this study, we developed a novel prevention technique using a falciform ligament patch (FLP) to prevent DSL among high-risk patients after gastrectomy. Materials and Methods: From January 2019 to July 2021, 14 patients who were judged to be at high risk for DSL during preoperative examinations or surgery were included in this retrospective study, and the FLP was applied to the duodenal stump. The falciform ligament was separated from the liver after duodenal transection during gastrectomy; the end part was used to cover the duodenal stump and was fixed using nonabsorbable polypropylene sutures. Results: In total, 14 patients who underwent FLP had one or two risk factors that were identified: 5 patients, gastric cancer duodenal invasion; 4 patients, gastric outlet obstruction (GOO); 1 patient, cancer involving the distal resection margin; 1 patient, duodenal gastrointestinal stromal tumor involving the distal resection margin; 1 patient, gastric cancer duodenal invasion and GOO; and 2 patients, cancer involving the distal resection margin and GOO. FLP construction was successful, and no patient developed complications of DSL. The average hospital stay was 11.9 days, and the patients were discharged without any morbidities after surgery. Conclusions: Therefore, the FLP can be used to prevent DSL among high-risk patients after gastrectomy.

A 3-year follow-up study of uncut Roux-en-Y reconstruction: clinical results and outcomes.

BACKGROUND: The goal of this study was to identify the clinical outcomes of uncut Roux-en-Y reconstruction in patients who underwent totally laparoscopic distal gastrectomy (TLDG) over 3-year follow-up. METHODS: From January 2016 to December 2017, 269 patients who underwent TLDG were enrolled in the study and analyzed retrospectively. They were classified into two groups according to the reconstruction method: uncut Roux-en-Y reconstruction (uncut RY) (n = 154) and Billroth II with Braun anastomosis (B-II/Braun) (n = 115). Postoperative endoscopic findings (residual food, bile reflux, gastritis, and esophagitis) and nutritional status (body weight, serum hemoglobin, total protein, and albumin levels) were assessed every 6 months for 3 years. RESULTS: Residual food was less frequent in the uncut RY group in the 6th month after TLDG (p = 0.022), but there were no differences between the two groups for the rest of the study period. The incidence of bile reflux and gastritis was low in the uncut RY group during all postoperative periods (all p < 0.001). In the B-II/Braun group, the frequency of reflux esophagitis was high in the 30th and 36th months after TLDG (both p < 0.001), and there were no differences between the two groups during the preceding periods. No significant differences were found with respect to nutritional status, such as body weight, serum hemoglobin, total protein, and albumin levels during all postoperative periods. CONCLUSIONS: Three-year follow-up outcomes showed that uncut RY can effectively reduce the incidence of bile reflux and gastritis in the remnant stomach compared to B-II/Braun after TLDG.

Actual 3-Year Survival After Reduced-Port Laparoscopic Distal Gastrectomy for Gastric Cancer (RpLDG): a Propensity Score Matching Analysis.

BACKGROUND: Total laparoscopic distal gastrectomy for early gastric cancer has been widely accepted; however, reduced-port laparoscopic distal gastrectomy has not gained the same popularity because of technical difficulties and oncologic safety issues. This study aimed to analyze the oncologic safety and short-term surgical outcomes of patients who underwent reduced-port laparoscopic distal gastrectomy (RpLDG) for gastric cancer. METHODS: Consecutive patients who underwent surgical treatment between January 2016 and May 2018 were included in this study. Of the 833 patients enrolled, 158 underwent RpLDG and were propensity-matched with 158 patients who underwent conventional port laparoscopic distal gastrectomy (CpLDG). The groups were compared in terms of short-term outcomes and disease-free and overall survival rates. RESULTS: The RpLDG group had shorter operation times (161.8 min vs. 189.0 min, p < 0.00) and shorter postoperative hospital stays (7.6 days vs. 9.1 days, p = 0.04) compared to the CpLDG group. Estimated blood loss was lower in the RpLDG group than in the CpLDG group (52.6 mL vs. 73.7 mL, p < 0.00), while hospital costs incurred by the RpLDG group were lower than those of the CpLDG group (10,033.7 vs. 11,016.8 USD, p < 0.00). No statistical differences were found regarding overall morbidity and occurrence of surgical complications of grade III or higher, as defined by the Clavien-Dindo classification. Furthermore, no significant differences between RpLDG and CpLDG were found in 3-year disease-free (99.4% vs. 98.1%; p = 0.42) and 3-year overall survival rates (98.7% vs. 96.8%; p = 0.25). CONCLUSION: Patients who underwent RpLDG had better short-term surgical outcomes than those who underwent CpLDG in terms of operation time, estimated blood loss, duration of hospital stay, and hospital costs. The oncologic safety of RpLDG was satisfactory.

Reducing Supply Cost by Standardization of Surgical Equipment in Laparoscopic Appendectomy.

BACKGROUND AND OBJECTIVES: Compensation for increased medical services from reimbursement systems are sometimes insufficient. Generally, appendectomies are performed by individual surgeons with their preferred instrument. Surgical equipment standardization is known to reduce medical cost without compromising patient safety. Hence, we investigated the effectiveness of surgical equipment standardization to reduce the required operative cost for laparoscopic appendectomy at our tertiary hospital. METHODS: Nine surgeons at our tertiary hospital agreed to use standardized equipment for laparoscopic appendectomy. We compared outcomes among patients who underwent laparoscopic appendectomy between December 2012 and June 2013 before standardization (control group) and between August 2015 and February 2016 after standardization. Participating provider and staff convenience was also surveyed using a questionnaire. RESULTS: The implementation of standardized equipment for laparoscopic appendectomy decreased intraoperative supply cost from US $552.92 to $450.17. Operative times also decreased from 73.8 to 53.3 minutes. However, hospital days and complication rates remained unchanged. Participants responded that surgical equipment standardization improved efficiency in the operating room and reduced the cost. CONCLUSION: Surgical equipment standardization in laparoscopic appendectomy is effective in reducing intraoperative supply cost without compromising patient safety.

Impending Rupture With a Twisted Huge Appendiceal Mucocele Treated With Totally Laparoscopic Resection: A Case Series.

Torsion of the appendix is rare, and appendiceal mucocele can be one of its causes. The first case was of a 49-year-old man who visited the emergency room (ER) for abdominal pain. Abdominal computed tomography (CT) showed appendiceal mucocele with suspected torsion and rupture. The patient underwent laparoscopic exploration and appendectomy. The second case was of a 69-year-old man who visited the ER for epigastric pain. Abdominal CT showed suspicious appendiceal mucocele with ischemic change, indicating torsion of the appendix. The twisted appendix was successfully removed by laparoscopic exploration. An appendiceal mucocele is one of the causes of twisted appendix. With torsion, the mucocele can be diagnosed as rupture by ischemia which may lead to pseudomyxoma peritonei. For this reason, open laparotomy has traditionally been preferred. However, an unruptured appendiceal mucocele or impending rupture with torsion of the appendiceal mucocele can be treated with totally laparoscopic surgery.

Clinical features of internal hernia after gastrectomy for gastric cancer.

Purpose: Internal hernia after gastrectomy is a rare but potentially life-threatening condition without surgical intervention. Clinical risk factors of internal hernia should, hence, be reviewed after gastrectomy. From 2008 to 2018, patients who underwent gastrectomy for gastric cancer were investigated. Methods: Abdominal computed tomography (CT) was used to screen for internal hernia, and surgical exploration was performed to confirm the diagnosis. Using retrospective statistical analysis, the incidence, characteristics, and risk factors were identified, and the characteristics of the internal hernia group were reviewed. Results: The overall incidence of internal hernia was 0.9%. From statistical analysis, it was found that laparoscopic surgery was almost five times riskier than open gastrectomy (odds ratio [OR], 4.947; 95% confidence interval [CI], 1.308-18.710; p = 0.019). Body mass index < 25 kg/m2 (OR, 4.596; 95% CI, 1.056-20.004; p = 0.042) and proximal gastrectomy (OR, 4.238; 95% CI, 1.072-16.751; p = 0.039) were also associated with internal hernia. Among 20 patients with internal hernia, 12 underwent laparotomy, and five had their bowels removed due to ischemia. All patients with bowel resected had suffered from short bowel syndrome. Conclusion: Suspecting an internal hernia should be an important step when a patient with a history of laparoscopic gastrectomy visits for medical care. When suspected, emergent screening through CT scan and surgical intervention should be considered as soon as possible to prevent lifetime complications accordingly.

Reduced fasting time in patients who underwent totally laparoscopic distal gastrectomy.

PURPOSE: The aim of this study was to analyze the effects of reduced fasting time on postoperative recovery in patients who underwent totally laparoscopic distal gastrectomy (TLDG). METHODS: This retrospective study included 347 patients who underwent TLDG. Patients were divided into 2 groups: reduced fasting time group (n = 139) and conventional feeding group (n = 208). We compared the total hospital cost and recovery parameters, such as postoperative complications, mean hospital stay, day of first flatus, initiation of soft diet, and serum CRP levels, between the 2 groups. RESULTS: The reduced fasting time group had a lower total hospital cost (P < 0.001) than the conventional feeding group. Regarding postoperative complications, there was no significant difference between the 2 groups (P = 0.085). Patients in the reduced fasting time group had a significantly shorter duration of mean hospital stay (P < 0.001), an earlier first flatus (P = 0.002), an earlier initiation of soft diet (P < 0.001), and lower level of serum CRP concentration (day of surgery, P = 0.036; postoperative days 2, 5, and 7, P = 0.01, 0.009, and 0.012, respectively) than patients in the conventional feeding group. CONCLUSION: Reduced fasting time can enhance postoperative recovery in patients who undergo TLDG and may reduce medical costs.

Potential Therapeutic Approaches for the Intussusception Through a Side-to-Side Jejunojejunal Anastomosis After Laparoscopic Gastrectomy.

We reviewed our experience with the management of intussusception presenting as a complication of laparoscopic gastrectomy (LG) and studied the feasibility of a laparoscopic intervention to treat or prevent this condition. We retrospectively analyzed the data of 12 patients diagnosed with intussusception, following gastrectomy, from 2008 to 2017, including clinical manifestations, incidence, post-LG time-interval before diagnosis, and treatment. Totally, 12/2300 gastrectomy patients (0.52%) developed intussusception. All 12 had undergone laparoscopic distal gastrectomy for gastric cancer (12/1250, 0.96%) and presented with intussusception through a side-to-side jejunojejunal anastomosis. The mean latency period was 423.8 (range: 86 to 1500) days. Four patients underwent emergent laparoscopic reduction of the efferent loop without bowel resection, along with fixation of the reduced jejunum to the afferent loop and the small bowel mesentery, to prevent a recurrence. One patient required open surgery with manual reduction and segmental resection of the gangrenous small bowel portion. All operated patients recovered without any complications. Intussusception resolved spontaneously in the remaining 7/12 patients. We found that a laparoscopic approach can be used for preventing or managing post-LG intussusception. We found that recurrence can be prevented or treated by anchoring and fixing the (reduced) efferent loop to the afferent loop and the small bowel mesentery.

Can Proximal Gastrectomy with Double-Tract Reconstruction Replace Total Gastrectomy? A Propensity Score Matching Analysis.

BACKGROUND: This retrospective cohort study compared proximal gastrectomy (PG) with double-tract reconstruction (DTR) versus total gastrectomy (TG) with Roux-en-Y reconstruction in terms of clinical outcomes. METHODS: All consecutive patients with upper early gastric cancer (EGC) who underwent PG-DTR or TG in 2008-2016 were selected. TG patients who matched PG-DTR patients in age, sex, body mass index, clinical stage, and ASA score were selected by propensity score matching. Groups were compared in terms of clinicopathological characteristics, clinical outcomes, early (≤ 30 days), late (> 30 days), and severe (Clavien-Dindo grade ≥ III) postoperative complications, 1-year reflux morbidity, recurrence, and mortality. RESULTS: Of 322 patients, 52 underwent PG-DTR. A matching TG group of 52 patients was selected. The PG-DTR group had smaller tumors (p = 0.02), smaller proximal and distal resection margins (p = 0.01, p < 0.01), and fewer retrieved lymph nodes (p < 0.01). PG-DTR associated with shorter times to diet and hospital stay (both p = 0.02). Groups did not differ in early (11.3 vs. 19.2%, p = 0.19), late (1.9 vs. 5.7%, p = 0.31), or severe complication rates (7.7 vs. 13.5%, p = 0.34). At 1 year, the groups did not differ in reflux symptoms (Visick score) or endoscopic esophagitis (Los Angeles Classification). There were no recurrences. Five-year overall survival rates were 100 and 81.6% (p = 0.02), respectively. CONCLUSION: PG-DTR associated with better clinical outcomes and survival. Complication and reflux rates were similar. PG-DTR may be suitable for upper EGC.

Reduction rate of C-reactive protein as an early predictor of postoperative complications and a reliable discharge indicator after gastrectomy for gastric cancer.

PURPOSE: Postoperative complications (PCs) after gastrectomy are associated with readmission and longer hospital stay. This study aimed to determine the role of CRP as an early predictor of PCs and a reliable discharge indicator after gastrectomy. METHODS: Clinicopathologic data and PCs of 613 patients who underwent gastrectomy for gastric cancer in 2015-2016 were retrospectively analyzed, including consecutive blood samples for CRP obtained preoperatively, at the operative day, and postoperatively. Following the Clavien-Dindo classification, the patients were divided into a group with major PCs and a group with minor/no PCs. Diagnostic accuracy was determined by the area under the receiver operating characteristic curve (AUC). Clinical factors related to major PCs were identified using univariate and multivariate logistic regression analyses. RESULTS: PCs occurred in 89 patients (14.5%). The most significant predictive factor for major PCs was a CRP concentration reduction rate of ≤38.1% (AUC, 0.82; sensitivity, 76.4%; specificity, 76.1%) between postoperative day (POD) 3 and 5 (R5), followed by ≤11.1% (AUC, 0.75; sensitivity, 73%; specificity, 76%) between POD 2 and 3 (R4). When both factors were applied (R4 ≤ 11.1% and R5 ≤ 38.1%), the specificity was 91.6%; when only one condition was satisfied (R4 ≤ 11.1% or R5 ≤ 38.1%), the sensitivity was 91%. CONCLUSION: CRP concentration reduction rates between POD 3 and 5 and between POD 2 and 3 were the best combination factors to predict PCs and indicate a safe discharge after gastrectomy for gastric cancer.

Atraumatic Liver Retraction Using Nelaton Catheters During Totally Laparoscopic Gastrectomy.

This study introduces a novel technique for liver retraction during laparoscopic gastrectomy and assesses its impact on postoperative recovery. This study included 139 patients in whom Nelaton catheters (n=57) or Nathanson retractors (n=82) were used for liver retraction. Serum liver enzyme levels were measured preoperatively and on the first, second, third, fifth, and seventh postoperative days. Clinicopathologic features and postoperative recovery variables between the 2 groups were compared. The aspartate aminotransferase, alanine aminotransferase, and C-reactive protein levels were significantly lower (P<0.001, P<0.001, and P=0.007, respectively), and the day of first flatus, the day of initiating a soft diet, and the length of hospital stay were shorter in the Nelaton catheter U-shaped retractor group than those seen in the Nathanson retractor group (P=0.035, P=0.002, and P=0.024, respectively). Atraumatic liver retraction with Nelaton catheters is recommended in laparoscopic gastrectomy.

Congenital adhesion band causing small bowel obstruction: What's the difference in various age groups, pediatric and adult patients?

BACKGROUND: A congenital adhesion band is a rare condition, but may induce a small bowel obstruction (SBO) at any age. However, only a few sporadic case reports exit. We aimed to identify the clinical characteristics of congenital adhesion band manifesting a SBO stratified by age group between pediatric and adult patients. METHODS: The medical records of all patients with a SBO between Jan 1, 2009 and Dec 31, 2015 were retrospectively reviewed. Cases associated with previous surgical procedure and cases of secondary obstruction due to inflammatory processes or tumor and other systemic diseases were excluded. The patients were divided into two groups according to age below or above 18 years: pediatric and adult. The basic clinical characteristics were analyzed and compared between groups. RESULTS: Of 251 patients with a SBO, 15 (5.9%) met the inclusion criteria; 10 cases in pediatric group (mean age 17.9 ± 38.7 months) and 5 cases in adult group (mean age 60.0 ± 19.7 years). The pediatric group (66.6%) included 3 neonates, 5 infants, and 2 school children. They usually presented with bilious vomiting (50.0%) and abdominal distention (60.0%), and demonstrated a high rate of early operation (80.0%) and bowel resection (70.0%). In contrast, the adult group (33.3%) presented with abdominal pain (100%) in all cases and underwent a relatively simple procedure of band release using a laparoscopic approach (60%). However, group differences did not reach statistical significance. In addition, two groups did not differ in the time interval to the operation or in the range of the operation (p = 0.089 vs. p = 0.329). No significant correlation was found between the time interval to the operation and the necessity of bowel resection (p = 0.136). There was no mortality in either group. CONCLUSIONS: Congenital adhesion band is a very rare condition with diverse clinical presentations across ages. Unlike adult patients, pediatric patients showed a high proportion of early operation and bowel resection. A good result can be expected with an early diagnosis and prompt management regardless of age.

Risk factors for lymph node metastasis in mucosal gastric cancer and re-evaluation of endoscopic submucosal dissection.

PURPOSE: The selection of the appropriate treatment strategy for patients with mucosal gastric cancer (MGC) remains controversial. In the present study, we aimed to determine the risk factors for lymph node (LN) metastasis in MGC and reassess the role of endoscopic submucosal dissection (ESD). METHODS: We examined 1,191 MGC patients who underwent curative gastrectomy between January 2005 and December 2014. We determined the clinicopathologic risk factors for LN metastasis among the MGC patients. RESULTS: Among 1,191 patients with MGC, 42 patients (3.5%) had LN metastasis. Univariate analysis indicated that age ≤ 50 years (P = 0.045), tumor invasion to the muscularis mucosa (P < 0.001), tumor size > 2 cm (P = 0.014), presence of ulceration (P = 0.01), diffuse type as per Lauren classification (P = 0.005), and undifferentiated-type histology (P = 0.001) were associated with LN metastasis. Moreover, multivariate analysis indicated that tumor invasion to the muscularis mucosa (P = 0.001; odds ratio [OR], 4.909), presence of ulceration (P = 0.036; OR, 1.982), and undifferentiated-type histology (P = 0.025; OR, 4.233) were independent risk factors for LN metastasis. In particular, LN metastasis was observed in some MGC cases with indications for ESD, including absolute indications (1 of 179, 0.6%) and expanded indications (9 of 493, 1.8%). CONCLUSION: Although MGC patients can be treated via ESD, we recommend that they undergo a more aggressive treatment strategy if they have tumor invasion to the muscularis mucosa, ulceration, or undifferentiated-type histology in the final pathology report.

Duodenal stump fistula after gastrectomy for gastric cancer: risk factors, prevention, and management.

PURPOSE: A duodenal stump fistula is one of the most severe complications after gastrectomy for gastric cancer. We aimed to analyze the risk factors for this problem, and to identify the methods used for its prevention and management. METHODS: We retrospectively reviewed the clinical data of 716 consecutive patients who underwent curative gastrectomy with a duodenal stump for gastric cancer between 2008 and 2013. RESULTS: A duodenal stump fistula occurred in 16 patients (2.2%) and there were 2 deaths in this group. Univariate analysis revealed age >60 years (odds ratio [OR], 3.09; 95% confidence interval [CI], 0.99-9.66), multiple comorbidities (OR, 4.23; 95% CI, 1.50-11.92), clinical T stage (OR, 2.91; 95% CI, 1.045-8.10), and gastric outlet obstruction (OR, 8.64; 95% CI, 2.61-28.61) to be significant factors for developing a duodenal stump fistula. Multivariate analysis identified multiple comorbidities (OR, 3.92; 95% CI, 1.30-11.80) and gastric outlet obstruction (OR, 5.62; 95% CI, 1.45-21.71) as predictors of this complication. CONCLUSION: Multiple comorbidities and gastric outlet obstruction were the main risk factors for a duodenal stump fistula. Therefore, preventive methods and aggressive management should be applied for patients at high risk.