Feasibility and safety of inserting transient biodegradable stents in the pylorus during pylorus-preserving gastrectomy for gastric cancer: a preliminary study in a porcine for proof of concept.

BACKGROUND: To evaluate whether insertion of self-biodegradable stent into the pylorus to prevent delayed-gastric emptying after pylorus-preserving gastrectomy is feasible and safe through porcine experiment. METHODS: Self-biodegradable dumbbell-shaped pyloric stents were designed from absorbable suture materials: poly(glycolide-co-caprolactone) (PGCL) or poly-p-dioxanone (PPDO). After gastrotomy on ten pigs, each stent was inserted: two shams, four PGCL stents, and four PPDO stents. Body weight (Bwt), body temperature (BT), complete blood cell (CBC) count, and plain X-ray were evaluated. On postoperative day (POD) 13, euthanasia was performed for histologic evaluation. RESULTS: Operation was successfully performed in all ten pigs. Without tagging suture, both stents migrated before POD 3. The migration was delayed up to POD 13, when the tagging sutures (-t) were applied between stent and stomach wall. Self-degradation of PGCL started from POD 3, and stents were completely excreted from the abdomen by POD 8. Although PPDO were also weakened as self-degradation progressed, its shape was maintained in gastrointestinal tract for 13 days. Unexpected sudden death occurred in the pig with PPDO-t2 on POD 10, which is more likely due to acute volvulus rather than stent-related complication. There was no significant difference between three groups in terms of Bwt, BT, CBC, and histology (sham vs. PGCL vs. PPDO, all p > 0.05). CONCLUSION: The concept of biodegradable stents made of absorbent suture material seems feasible in porcine experiment. Among them, PGCL which has shown rapid absorption, appears to be a more suitable material for transient pyloric absorbable stent when considering safety aspect.

Feasibility and safety of pure single-incision laparoscopic total and proximal gastrectomy for early gastric cancer: propensity score-matched comparison to multiport totally laparoscopic approach.

BACKGROUND: There have been few studies regarding the feasibility and safety of pure single-incision laparoscopic total gastrectomy (SITG) or proximal gastrectomy (SIPG) for early gastric cancer (EGC). The purpose of this study was to analyze the surgical outcome of all consecutive SITG or SIPG cases compared with multiport laparoscopic total gastrectomy (MLTG) or proximal gastrectomy (MLPG) for EGC. METHODS: We analyzed all consecutive SITG or SIPG cases with double-tract reconstruction for ECG, including the initial case, between March 2013 and December 2021. SITG/SIPG was performed on patients without significant systemic comorbidities through a 3-4 cm vertical transumbilical incision. SITG/SIPG was matched to multiport laparoscopic total or proximal gastrectomy (MLTG/MLPG) cases performed in the same period using a 1:3 propensity score matching, including sex, body mass index (BMI), age and type of resection, year of operation, and institution as covariates. We compared perioperative clinicopathological characteristics and early postoperative morbidity within 1 month after surgery between the SITG/SIPG and MLTG/MLPG groups. RESULTS: In total, 21 patients with SITG and 15 patients with SIPG were compared with those with MLTG (n = 264) and MLPG (n = 220). No conversion to an open or multiport approach occurred in the SITG/SIPG group. After matching, operation time was similar between SITG/SIPG and MLTG/MLPG (223.9 ± 63.5 min vs 234.8 ± 68.7 min, P = 0.402). Length of stay was not significantly different between SITG/SIPG and MLTG/MLPG (11.9 ± 15.4 days vs 8.4 ± 5.0 days, P = 0.210). The average number of retrieved lymph nodes was not significantly different between SITG and MLTG (53.1 ± 16.3 vs 63.2 ± 27.5, P = 0.115), but it was significantly higher in SIPG than MLPG (59.6 ± 27.2 vs 46.0 ± 19.7, P = 0.040). The overall complication rate (30.6% vs 25.9%, P = 0.666) and Clavien-Dindo grade III or higher complication rates (13.9% vs 6.5%, P = 0.175) were not significantly different between the SITG/SIPG and MLTG/MLPG groups. CONCLUSION: Cautious adoption of SITG/SIPG procedures for EGC is feasible and safe.

Exploring ideal operative time for best outcomes in gastric cancer surgery: A multi-institutional study based on KLASS-07 database.

Objective: While a rushed operation can omit essential procedures, prolonged operative time results in higher morbidity. Nevertheless, the optimal operative time range remains uncertain. This study aimed to estimate the ideal operative time range and evaluate its applicability in laparoscopic cancer surgery. Methods: A prospectively collected multicenter database of 397 patients who underwent laparoscopic distal gastrectomy were retrospectively reviewed. The ideal operative time range was statistically calculated by separately analyzing the operative time of uneventful surgeries. Finally, intraoperative and postoperative outcomes were compared among the shorter, ideal, and longer operative time groups. Results: The statistically calculated ideal operative time was 135.4-165.4 min. The longer operative time (LOT) group had a lower rate of uneventful, perfect surgery than the ideal or shorter operative time (IOT/SOT) group (2.8% vs. 8.8% and 2.2% vs. 13.4%, all P<0.05). Longer operative time increased bleeding, postoperative morbidities, and delayed diet and discharge (all P<0.05). Particularly, an uneventful, perfect surgery could not be achieved when the operative time exceeded 240 min. Regardless of ideal time range, SOT group achieved the highest percentage of uneventful surgery (13.4%), which was possible by surgeon's ability to retrieve a higher number of lymph nodes and perform ≥150 gastrectomies annually. Conclusions: Operative time longer than the ideal time range (especially ≥240 min) should be avoided. If the essential operative procedure were faithfully conducted without compromising oncological safety, an operative time shorter than the ideal range leaded to a better prognosis. Efforts to minimize operative time should be attempted with sufficient surgical experience.

Remission of type 2 diabetes after gastrectomy for gastric cancer: diabetes prediction score.

BACKGROUND: Although type 2 diabetes (T2D) remission after gastric cancer surgery has been reported, little is known about the predictors of postoperative T2D remission. METHODS: This study used data from a nationwide cohort provided by the National Health Insurance Service in Korea. We developed a diabetes prediction (DP) score, which predicted postoperative T2D remissions using a logistic regression model based on preoperative variables. We applied machine-learning algorithms [random forest, XGboost, and least absolute shrinkage and selection operator (LASSO) regression] and compared their predictive performances with those of the DP score. RESULTS: The DP score comprised five parameters: baseline body mass index (< 25 or ≥ 25 kg/m2), surgical procedures (subtotal or total gastrectomy), age (< 65 or ≥ 65 years), fasting plasma glucose levels (≤ 130 or > 130 mg/dL), and antidiabetic medications (combination therapy including sulfonylureas, combination therapy not including sulfonylureas, single sulfonylurea, or single non-sulfonylurea]). The DP score showed a clinically useful predictive performance for T2D remission at 3 years after surgery [training cohort: area under the receiver operating characteristics (AUROC) 0.73, 95% confidence interval (CI), 0.71-0.75; validation cohort: AUROC 0.72, 95% CI 0.69-0.75], which was comparable to that of the machine-learning models (random forest: AUROC 0.71, 95% CI 0.68-0.74; XGboost: AUROC 0.70, 95% CI 0.67-0.73; LASSO regression: AUROC 0.75, 95% CI 0.73-0.78 in the validation cohort). It also predicted the T2D remission at 6 and 9 years after surgery. CONCLUSIONS: The DP score is a useful scoring system for predicting T2D remission after gastric cancer surgery.

Glucose metabolic profiles evaluated by PET associated with molecular characteristic landscape of gastric cancer.

BACKGROUND: Although FDG-PET is widely used in cancer, its role in gastric cancer (GC) is still controversial due to variable [18F]fluorodeoxyglucose ([18F]FDG) uptake. Here, we sought to develop a genetic signature to predict high FDG-avid GC to plan individualized PET and investigate the molecular landscape of GC and its association with glucose metabolic profiles noninvasively evaluated by [18F]FDG-PET. METHODS: Based on a genetic signature, PETscore, representing [18F]FDG avidity, was developed by imaging data acquired from thirty patient-derived xenografts (PDX). The PETscore was validated by [18F]FDG-PET data and gene expression data of human GC. The PETscore was associated with genomic and transcriptomic profiles of GC using The Cancer Genome Atlas. RESULTS: Five genes, PLS1, PYY, HBQ1, SLC6A5, and NAT16, were identified for the predictive model for [18F]FDG uptake of GC. The PETscore was validated in independent PET data of human GC with qRT-PCR and RNA-sequencing. By applying PETscore on TCGA, a significant association between glucose uptake and tumor mutational burden as well as genomic alterations were identified. CONCLUSION: Our findings suggest that molecular characteristics are underlying the diverse metabolic profiles of GC. Diverse glucose metabolic profiles may apply to precise diagnostic and therapeutic approaches for GC.

Clinical significance of lipid droplets formed in the peritoneal fluid after laparoscopic surgery for gastric cancer.

BACKGROUND: Several studies have previously reported that laparoscopic surgery using an energy sealing device generates hazardous surgical smoke. However, the droplets appearing on the surface of peritoneal fluid irrigated with saline, after dissection phase of laparoscopic gastrectomy were ignored for a long time. This study aimed to investigate the composition and clinical significance of these droplet particles. METHODS: This study prospectively enrolled 15 patients with early gastric cancer (cT1NanyM0) who were scheduled for laparoscopic gastrectomy. Floating phases of peritoneal irrigation fluid containing droplets in dissected area were retrieved before and after surgical dissection. Using gas chromatography analysis, the areas under the peak were compared between the samples retrieved before and after surgical dissection. We also analyzed if the area value with significant change was related to the inflammatory response. RESULTS: In gas chromatography, the area values after laparoscopic surgical dissection were significantly increased in 10 out of 37 kinds of fatty acids, compared to those before surgical dissection. The significant increase in area value of α-linoleic and eicosadienoic acids were positively correlated with the elevated level of C-reactive protein at postoperative day 2 (Spearman's ρ = 0.843, P < 0.001; Spearman's ρ = 0.785, P = 0.001). CONCLUSIONS: The lipid droplets, generated after laparoscopic lymphadenectomy during gastric cancer surgery, contained various types of fatty acids, and some of them have been found to be associated with inflammatory response.

Prediction Model for Screening Patients at Risk of Malnutrition After Gastric Cancer Surgery.

BACKGROUND: Malnutrition after gastrectomy is associated with a poor prognosis; however, no accurate model for predicting post-gastrectomy malnutrition exists. Hence, we conducted a retrospective study to develop a prediction model identifying gastric cancer patients at high risk of malnutrition after gastrectomy. METHOD: Gastric cancer patients who underwent curative gastrectomy with more than one weight measurement during a 3-year follow-up period were included. Malnutrition was defined as body mass index (BMI) < 18.5 kg/m2 according to the European Society of Clinical Nutrition and Metabolism diagnostic criteria. BMI-loss pattern was analyzed using a group-based trajectory model. A prediction model for malnutrition 6 months after gastrectomy was developed based on significant risk factors, and then validated. RESULTS: Overall, 1421 patients were examined. The BMI-loss trajectory model showed significant BMI loss at 6 months after gastrectomy. Severe BMI loss (mean 21.5%; n = 109) was significantly associated with the elderly, female sex, higher preoperative BMI, advanced cancer stage, open surgery, total gastrectomy, Roux-en-Y reconstruction, chemotherapy, and postoperative complications (all p < 0.05). Malnutrition 6 months after gastrectomy was observed in 152 (11.9%) of 1281 patients. Preoperative BMI, sex, and type of operation were included in the final prediction model as predictive factors (p < 0.05). The C-index of the developmental set and bootstrap validation of the prediction model was 0.91 (95% confidence interval 0.89-0.94) and 0.91, respectively. CONCLUSION: The prediction model for the risk of malnutrition 6 months after gastrectomy was accurately developed, with three independent risk factors: low preoperative BMI, female sex, and total or proximal gastrectomy.

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.

Preservation of hepatic branch of the vagus nerve reduces the risk of gallstone formation after gastrectomy.

BACKGROUND: Injury to the vagus nerve has been proposed to be associated with occurrence of gallstones after gastrectomy. We investigated the effect of preservation of hepatic branch of the vagus nerve on prevention of gallstones during laparoscopic distal (LDG) and pylorus-preserving gastrectomy (LPPG). METHODS: Preservation of the vagus nerve was reviewed of cT1N0M0 gastric cancer patients underwent LDG (n = 323) and LPPG (n = 144) during 2016-2017. Presence of gallstones was evaluated by ultrasonography (US) and computed tomography (CT). Incidences of gallstones were compared between the nerve preserved (h-DG, h-PPG) group and sacrificed (s-DG, s-PPG) group. Clinicopathological features were also compared. RESULTS: The 3-year cumulative incidence of gallstones was lower in the h-DG (2.7%, n = 85) than the s-DG (14.6%, n = 238) (p = 0.017) and lower in the h-PPG (1.6%, n = 123) than the s-PPG (12.9%, n = 21) (p = 0.004). Overall postoperative complication rate was similar between the h-DG and s-DG (p = 0.861) as well as between the h-PPG and s-PPG (p = 0.768). The number of retrieved lymph nodes station #1 and 3-year recurrence-free survival were not significantly different between the preserved group and sacrificed group. Injury to the vagus nerve (p = 0.001) and high body mass index (BMI) (≥ 27.5 kg/m2) (p = 0.040) were found to be independent risk factors of gallstone formation in multivariate analysis. CONCLUSIONS: Preservation of hepatic branch of the vagus nerve can be recommended for LDG as well as LPPG of early gastric cancer patients to reduce postoperative gallstone formation.

Current Status and Trends of Minimally Invasive Gastrectomy in Korea.

Since its introduction in the early 1990s, laparoscopic gastrectomy has been widely accepted for the treatment of gastric cancer worldwide. In the last decade, the Korean Laparoendoscopic Gastrointestinal Surgery Study group performed important clinical trials and exerted various efforts to enhance the quality of scientific knowledge and surgical techniques in the field of gastric cancer surgery. Laparoscopic gastrectomy has shifted to a new era in Korea due to recent advances and innovations in technology. Here, we discuss the recent updates of laparoscopic gastrectomy-namely, reduced-port, single-incision, robotic, image-guided, and oncometabolic surgery.

Prognostic Impact of Frozen Section Investigation and Extent of Proximal Safety Margin in Gastric Cancer Resection.

BACKGROUND AND AIMS: Guidelines propose different extents of macroscopic proximal margin for gastric cancer and frozen margin investigation in selected cases, but data is lacking. This study was to evaluate the necessary extent of macroscopic proximal margin, accuracy of frozen margin investigation, and prognostic impact of tumor-free proximal margin length in pT2-pT4 gastric cancer. STUDY DESIGN: Proximal and distal frozen margins were routinely investigated intraoperatively in all pT2-pT4 gastric cancers resected between 2011 and 2017. Macroscopic and microscopic proximal margin lengths were correlated. For R0-resections, survival analysis was performed for distal gastrectomy (DG) with microscopic proximal margin length ≤3 cm versus >3 cm. RESULTS: Overall, 1484 patients were included. Microscopic proximal margin lengths were macroscopically more often misestimated in diffuse histology (P = 0.0004), but extent of underestimation in centimeter was similar to intestinal and mixed/undetermined type (P = 0.134). Fifteen cases (1.0%) resulted in R1-resection, 10 at distal, and 5 at proximal margin but none with macroscopic proximal margin ≥3 cm and negative frozen section. Overall agreement of frozen margin and final pathology was 2951/2968 (99.4%). Proximal margin length in DG did not correlate with survival or recurrence in R0-resected patients. DISCUSSION: Diffuse histology is at higher risk for underestimation of proximal margin length, but extent of underestimation is similar in other Laurén subtypes. If ≥3 cm macroscopic proximal margin length is applied with intraoperative frozen margin confirmation, R1-resection can be avoided. CONCLUSION: In pT2-T4a gastric cancer, proximal margin of ≥3 cm plus frozen margin confirmation provides high oncological safety. In DG patients with R0-resection, proximal margin length does not correlate with survival or recurrence.

Prediction of Postoperative Mortality in Patients with Organ Failure After Gastric Cancer Surgery.

BACKGROUND: Scarce data are available on the characteristics of postoperative organ failure (POF) and mortality after gastrectomy. We aimed to describe the causes of organ failure and mortality related to gastrectomy for gastric cancer and to identify patients with POF who are at a risk of failure to rescue (FTR). METHODS: The study examined patients with POF or in-hospital mortality in Seoul National University Hospital between 2005 and 2014. We identified patients at a high risk of FTR by analyzing laboratory findings, complication data, intensive care unit records, and risk scoring including Acute Physiology and Chronic Health Evaluation (APACHE) IV, Sequential Organ Failure Assessment (SOFA) score, and Simplified Acute Physiology Score (SAPS) 3 at ICU admission. RESULTS: Among the 7304 patients who underwent gastrectomy, 80 (1.1%) were identified with Clavien-Dindo classification (CDC) grade ≥ IVa. The numbers of patients with CDC grade IVa, IVb, and V were 48 (0.66%), 11 (0.15%), and 21 (0.29%), respectively. Pulmonary failure (43.8%), surgical site complication (27.5%), and cardiac failure (13.8%) were the most common causes of POF and mortality. Cancer progression (100%) and cardiac events (45.5%) showed high FTR rates. In univariate analysis, acidosis, hypoalbuminemia, SOFA, APACHE IV, and SAPS 3 were identified as risk factors for FTR (P < 0.05). Finally, SAPS 3 was identified as an independent predictive factor for FTR. CONCLUSIONS: Cancer progression and acute cardiac failure were the most lethal causes of FTR. SAPS 3 is an independent predictor of FTR among POF patients after gastrectomy.

Near-infrared fluorescence-guided surgery using indocyanine green facilitates secure infrapyloric lymph node dissection during laparoscopic distal gastrectomy.

PURPOSE: We aimed to investigate the usefulness of near-infrared indocyanine green (ICG)-enhanced fluorescence guidance for infrapyloric LN dissection in laparoscopic distal gastrectomy. METHODS: This study enrolled patients with early gastric cancer scheduled for laparoscopic distal gastrectomy. After intraoperative submucosal injection of ICG (0.1 mg/mL), LN dissection was conducted under near-infrared ICG fluorescence guidance. The operation time, bleeding events during infrapyloric LN dissection were analyzed. Cases were retrospectively 1:3 propensity-score matched to patients who underwent laparoscopic distal gastrectomy without ICG injection. RESULTS: The mean time from midline omentectomy to exposure of the right gastroepiploic vein was significantly shorter in the ICG group (n = 20) than in the non-ICG group (n = 60) (13.05 ± 5.77 vs 18.68 ± 7.92 min; p = 0.001), and the incidence of bleeding during infrapyloric LN dissection was lower in the ICG group (20% vs 68.3%, p < 0.001). The two groups did not differ significantly regarding the number of LNs retrieved from the infrapyloric area (p = 0.434). CONCLUSIONS: Near-infrared ICG fluorescence guidance facilitates safe and fast infrapyloric LN dissection in laparoscopic distal gastrectomy.

Pylorus-preserving gastrectomy for early cancer involving the upper third: can we go higher?

BACKGROUND: Pylorus-preserving gastrectomy (PPG) is commonly performed for early gastric cancer (EGC) located in middle third of the stomach. We investigated the surgical, oncological, and functional outcomes of PPG involving the upper third of stomach. METHODS: We included all patients of the period 2013-2016 who underwent PPG, distal subtotal gastrectomy (DSG), and total gastrectomy (TG) for EGC involving the upper third by carefully defining the localization. Surgical, oncological, and functional outcome analyses included postoperative morbidity, lymph-node metastasis, tumor recurrence, postoperative body weight, body mass index, hemoglobin, total protein, albumin, quantification of intraabdominal fat, and gallstone development. RESULTS: Overall, 288 cases were analyzed: 145 PPG, 61 DSG, and 82 TG. In the study period, patients potentially underwent PPG for EGC involving the upper third, if enough proximal remnant stomach was found whilst achieving a sufficient proximal margin. PPG resulted in less operation time (p < 0.001), less blood loss (p = 0.002) and lower postoperative morbidity compared to TG. For lymph-node (LN) stations being resected in all groups, no difference was found in number of resected LN. Recurrence-free survival was similar for all groups. PPG showed advantages regarding postoperative body weight, hemoglobin, total protein, albumin in postoperative 6 and 12 month follow-up. Lowest decrease of abdominal fat area after 12 months was seen for PPG. Gallstone incidence was significantly lower after PPG compared to TG (p < 0.001). CONCLUSIONS: For EGC involving the upper third, PPG can be another good option with lower postoperative morbidity, better functional outcomes, and same oncological safety.

Clinical outcomes of intraoperative manual dilatation of pylorus in pylorus-preserving gastrectomy: a retrospective analysis.

BACKGROUND: Delayed gastric emptying is one of the most disturbing complications of pylorus-preserving gastrectomy (PPG) and it increases hospital stay. We investigated the clinical outcome of intraoperative manual dilatation of the pylorus as a preventive method of pyloric spasm after PPG. MATERIALS AND METHODS: We reviewed gastric cancer patients who underwent PPG between January 2014 and December 2016 at Seoul National University Hospital by a single surgeon. During operation, manual dilatation (MD) was performed after laparoscopic dissection and gastric resection by mini-laparotomy. Pyloric stenosis was diagnosed by the finding of severe narrowing in pylorus on upper gastrointestinal series (UGIS), if patients suffered from postprandial abdominal fullness and discomfort. Patient's characteristics, surgical data and complication data were reviewed and compared between the groups (MD vs non-MD). RESULTS: 232 patients were included in this study. 93 patients underwent manual dilatation (40.1%). The overall complication rate was 12.9% in the MD group and 18.7% in the non-MD group (p = 0.242). Mean postoperative stay was 10.0 ± 5.8 in the MD group versus 10.9 ± 8.4 in the non-MD group (p = 0.304). Only one case suffered pylorus stenosis in the MD group (1.1%) but there were twelve cases seen in the non-MD group (8.6%), which reflects a significant difference (p = 0.019). CONCLUSION: Simple intraoperative manual dilatation of pylorus may provide prevention from pyloric stenosis caused by pyloric spasms for patients who undergo PPG.

The anatomical configuration of the splenic artery influences suprapancreatic lymph node dissection in laparoscopic gastrectomy: analysis using a 3D volume rendering program.

BACKGROUND: The aim of this study is to categorize splenic artery and vein configurations, and examine their influence on suprapancreatic lymph node (LN) dissection in laparoscopic gastrectomy. METHODS: Digital Imaging and Communications in Medicine images from 169 advanced cancer patients who underwent laparoscopic gastrectomy with D2 dissection were used to reconstruct perigastric vessels in 3D using a volume rendering program (VP Planning®). Splenic artery and vein configuration were classified depending on the relative position of their lowest part in regard to the pancreas. Number of resected LNs and surgical outcomes were analyzed. RESULTS: The splenic artery was categorized as superficial (36.7%), middle (49.1%), and concealed (14.2%), and the splenic vein was categorized as superior (6.5%), middle (42.0%), and inferior to the pancreas (51.5%). The number of resected LNs around the proximal half of the splenic artery (#11p) and the proportion of the splenic vein located inferiorly to the pancreas were significantly higher in splenic arteries of concealed types. LN metastasis of station #7 was an independent risk factor of LN metastasis in station #11p (p = 0.010). Concealed types showed a tendency towards longer operating times, more blood loss, longer hospital stays, and a higher postoperative morbidity. CONCLUSION: Concealed types of splenic artery are associated with an increased difficulty in the dissection of LN station #11p around the splenic artery. A 3D volume rendering program is a useful tool to rapidly and intuitively identify individual anatomical variations, to plan a tailored surgical strategy, and to predict potential challenges.

Comprehensive Analysis of the Neutrophil-to-Lymphocyte Ratio for Preoperative Prognostic Prediction Nomogram in Gastric Cancer.

BACKGROUND: The role of neutrophil-to-lymphocyte ratio (NLR) and preoperative prediction model in gastric cancer is controversial, while postoperative prognostic models are available. This study investigated NLR as a preoperative prognostic indicator in gastric cancer. METHODS: We reviewed patients with primary gastric cancer who underwent surgery during 2007-2010. Preoperative clinicopathologic factors were analyzed with their interaction and used to develop a prognosis prediction nomogram. That preoperative prediction nomogram was compared to a nomogram using pTNM or a historical postoperative prediction nomogram. The contribution of NLR to a preoperative nomogram was evaluated with integrated discrimination improvement (IDI). RESULTS: Using 2539 records, multivariable analysis revealed that NLR was one of the independent prognostic factors and had a significant interaction with only age among other preoperative factors (especially significant in patients < 50 years old). NLR was constantly significant between 1.1 and 3.1 without any distinctive cutoff value. Preoperative prediction nomogram using NLR showed a Harrell's C-index of 0.79 and an R2 of 25.2%, which was comparable to the C-index of 0.78 and 0.82 and R2 of 26.6 and 25.8% from nomogram using pTNM and a historical postoperative prediction nomogram, respectively. IDI of NLR to nomogram in the overall population was 0.65%, and that of patients < 50 years old was 2.72%. CONCLUSIONS: NLR is an independent prognostic factor for gastric cancer, especially in patients < 50 years old. A preoperative prediction nomogram using NLR can predict prognosis of gastric cancer as effectively as pTNM and a historical postoperative prediction nomogram.

Bolus exposure as a novel predictor of postoperative symptom resolution after laparoscopic nissen fundoplication: A two-institutional retrospective cohort study.

BACKGROUND: Even in the absence of definite evidence of pathological acid reflux, antireflux surgery (ARS) can still effectively improve gastroesophageal reflux symptoms. Nonetheless, predicting postoperative reflux symptom improvement has been primarily dependent on acid-based parameters. No objective index reflecting both acid and non-acid reflux was identified to select ARS candidates. MATERIALS AND METHODS: Prospectively collected data of 121 patients with gastroesophageal reflux disease (GERD), who underwent laparoscopic Nissen fundoplication from two institutions, were retrospectively reviewed. The patients reported preoperative and postoperative GERD symptoms using the Korean version of the GERD questionnaire, along with the gastroesophageal reflux disease-health-related quality of life (GERD-HRQL). The patients assessed for reflux symptoms using bolus exposure, acid exposure time (AET), and DeMeester score (DMS) as measurements were selected. For each reflux parameter, its association, correlation, and predictive capacity of the degree of postoperative symptom resolution were analyzed using chi-squared tests, point-biserial correlations, logistic regression analyses, and receiver operating characteristic curve analyses. RESULTS: 72 patients were eligible for this study. Bolus exposure was superior to the other parameters in terms of the degree of association and correlation with resolution of typical symptoms. Bolus exposure also showed a higher diagnostic accuracy in predicting the resolution of epigastric pain (area under the curve [AUC]=0.723, P=0.013) and regurgitation (AUC=0.981, P<0.001). Secondary analyses were performed in patients without pathological reflux, defined as the DMS-negative (DMS<14.7) or AET-negative (AET<6%) groups. In the secondary analyses, bolus exposure showed considerable diagnostic accuracy with statistical significance for all typical symptoms in both in the DMS-negative (heartburn: AUC=0.717, P=0.025; epigastric pain: AUC=0.717, P=0.025; regurgitation: AUC=0.975, P<0.001) and AET-negative (heartburn: AUC=0.681, P=0.045; epigastric pain: AUC=0.749, P=0.009; regurgitation: AUC=0.975, P<0.001) groups. CONCLUSION: Bolus exposure, a parameter of total reflux, was superior to AET or DMS in defining candidates for ARS. Further studies investigating the surgical indications for ARS in patients with non-acid reflux using bolus exposure are required.

Morbidity and Mortality After Laparoscopy-Assisted Distal Gastrectomy and Totally Laparoscopic Distal Gastrectomy to Treat Gastric Cancer: An Interim Report: A Phase III Multicenter, Prospective, Randomized Trial (The KLASS-07 Trial).

PURPOSE: We conducted a randomized prospective trial (KLASS-07 trial) to compare laparoscopy-assisted distal gastrectomy (LADG) and totally laparoscopic distal gastrectomy (TLDG) for gastric cancer. In this interim report, we describe short-term results in terms of morbidity and mortality. METHODS AND METHODS: The sample size was 442 participants. At the time of the interim analysis, 314 patients were enrolled and randomized. After excluding patients who did not undergo planned surgeries, we performed a modified per-protocol analysis of 151 and 145 patients in the LADG and TLDG groups, respectively. RESULTS: The baseline characteristics, including comorbidity status, did not differ between the LADG and TLDG groups. Blood loss was somewhat higher in the LADG group, but statistical significance was not attained (76.76±72.63 vs. 62.91±65.68 mL; P=0.087). Neither the required transfusion level nor the operation or reconstruction time differed between the 2 groups. The mini-laparotomy incision in the LADG group was significantly longer than the extended umbilical incision required for specimen removal in the TLDG group (4.79±0.82 vs. 3.89±0.83 cm; P<0.001). There were no between-group differences in the time to solid food intake, hospital stay, pain score, or complications within 30 days postoperatively. No mortality was observed in either group. CONCLUSIONS: Short-term morbidity and mortality rates did not differ between the LADG and TLDG groups. The KLASS-07 trial is currently underway. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03393182.

Reappraisal of optimal reconstruction after distal gastrectomy - a study based on the KLASS-07 database.

BACKGROUNDS: This study aimed to compare the incidence of bile reflux, quality of life (QoL), and nutritional status among Billroth II (BII), Billroth II with Braun anastomosis (BII-B), and Roux-en-Y (RY) reconstruction after laparoscopic distal gastrectomy (LDG). MATERIALS AND METHODS: We reviewed the prospective data of 397 patients from a multicentre database who underwent LDG for gastric cancer between 2018 and 2020 at 20 tertiary teaching hospitals in Korea. Postoperative endoscopic findings, QoL surveys using the European Organization for Research and Treatment of Cancer questionnaire (C30 and STO22), and nutritional and surgical outcomes were compared among groups. RESULTS: In endoscopic findings, bile reflux was the lowest in the RY group ( n =67), followed by the BII-B ( n =183) and BII groups ( n =147) at 1 year (3.0 vs. 67.8 vs. 84.4%, all P <0.05). The anti-reflux capability of BII-B was statistically better than that of BII, but not as perfect as that of RY. From the perspective of QoL, BII-B was not inferior to RY, but better than BII reconstruction in causing fewer STO22 reflux symptoms at 6 and 12 months. However, only RY caused fewer C30 nausea symptoms than BII at 6 and 12 months, but not BII-B. Nutritional status and morbidities were similar among the three groups, and the operative time did not differ between the BII-B and RY groups. CONCLUSIONS: BII-B cannot substitute for RY in preventing bile reflux, shortening the operative time, or reducing morbidities. Regarding short-term QoL, BII-B was sufficient to reduce STO22 reflux symptoms but failed to reduce C30 nausea symptoms postoperatively.