Long-term Oncologic Outcomes of Robotic Total Gastrectomy for Advanced Gastric Cancer.

PURPOSE: Although laparoscopic distal gastrectomy has rapidly replaced open distal gastrectomy, laparoscopic total gastrectomy (LTG) is less frequently performed owing to technical difficulties. Robotic surgery could be an appropriate minimally invasive alternative to LTG because it alleviates the technical challenges posed by laparoscopic procedures. However, few studies have compared the oncological safety of robotic total gastrectomy (RTG) with that of LTG, especially for advanced gastric cancer (AGC). Herein, we aimed to assess the oncological outcomes of RTG for AGC and compare them with those of LTG. MATERIALS AND METHODS: We retrospectively reviewed 147 and 204 patients who underwent RTG and LTG for AGC, respectively, between 2007 and 2020. Long-term outcomes were compared using inverse probability of treatment weighting (IPTW). RESULTS: After IPTW, the 2 groups exhibited similar clinicopathological features. The 5-year overall survival was comparable between the 2 groups (88.5% [95% confidence interval {CI}, 79.4%-93.7%] after RTG and 87.3% [95% CI, 80.1%-92.0%]) after LTG; log-rank P=0.544). The hazard ratio (HR) for death after RTG compared with that after LTG was 0.73 (95% CI, 0.40-1.33; P=0.304). The 5-year relapse-free survival was also similar between the 2 groups (75.7% [95% CI, 65.2%-83.4%] after RTG and 76.4% [95% CI, 67.9%-83.0%] after LTG; log-rank P=0.850). The HR for recurrence after RTG compared with that after LTG was 0.93 (95% CI, 0.60-1.46; P=0.753). CONCLUSIONS: Our findings revealed that RTG and LTG for AGC had similar long-term outcomes. RTG is an oncologically safe alternative to LTG and has technical advantages.

The effects of sarcopenic obesity on immediate postoperative outcomes after pancreatoduodenectomy: a retrospective cohort study.

Purpose: Several studies have evaluated the impact of sarcopenic obesity (SO) on postoperative complications, including postoperative pancreatic fistula (POPF), in patients undergoing pancreatoduodenectomy (PD). Previous studies have shown that SO increases POPF, but it remains unclear whether SO increases postoperative complications. In this study, we aimed to determine the relationship between SO and immediate postoperative complications. Methods: From January 2005 to December 2019, the medical records of patients who underwent PD for periampullary cancer were retrospectively reviewed. Skeletal muscle index (SMI) and visceral fat area (VFA) were calculated from preoperative computed tomography images. Patients with high VFA were classified as obese, while those with low SMI were classified as sarcopenic. Patients were divided into 4 groups: normal group, sarcopenia only group, obesity only group, and SO group. Postoperative outcomes were compared between groups, and factors affecting postoperative complications were analyzed by multivariate analysis. Results: Normal group (n = 176), sarcopenia only group (n = 130), obesity only group (n = 207), and SO group (n = 117) were analyzed retrospectively. SO group had significantly more frequent major complications compared to the normal group (P = 0.006), as well as a significantly more frequent clinically relevant POPF compared to the other groups (P = 0.002). In multivariate analysis, SO was an independent risk factor for major complications (P = 0.008) and clinically relevant POPF (P = 0.003). Conclusion: SO is a factor associated with poor immediate postoperative outcomes after PD for periampullary cancer.

Differential Impact of Subcutaneous and Visceral Fat on Bone Changes after Gastrectomy.

BACKGRUOUND: Osteoporosis and fragility fractures are crucial musculoskeletal complications in long-term survivors of gastric cancer. However, the relationship between changes in body composition after gastrectomy and bone loss has not been investigated. Therefore, this study aimed to explore whether computed tomography (CT)-derived body composition parameters are associated with bone loss after gastrectomy in patients with gastric cancer. METHODS: We retrospectively reviewed medical records and abdomen CT scans of patients who underwent gastrectomy at Yonsei University Severance Hospital between 2009 and 2018. Patients with non-metastatic gastric adenocarcinoma and preoperative and postoperative non-contrast CT scans were analyzed. Section area of skeletal muscle (SMA), visceral fat (VFA), and subcutaneous fat (SFA) were assessed using semi-automatic segmentation software. Changes in trabecular bone attenuation of L1 mid-vertebra level (L1 Hounsfield units [HU]) were measured. RESULTS: Fifty-seven patients (mean age, 65.5±10.6; 70.2% males) were analyzed, and the median duration was 31 months. Fortyseven patients (82.5%) lost weight after gastrectomy. Baseline SMA and VFA did not differ between the bone loss and preserved groups; however, baseline SFA was significantly higher in the bone preserved group than in the bone loss group (P=0.020). In a multivariable linear regression model adjusted for confounding factors, one standard deviation higher VFA at baseline was associated with greater annualized L1 HU loss (%) (P=0.034). However, higher preoperative SFA was associated with protection against bone loss after gastrectomy (P=0.025). CONCLUSION: Higher preoperative SFA exhibited a protective effect against bone loss after gastrectomy in patients with non-metastatic gastric cancer, whereas VFA exhibited a negative effect.

Proximal Gastrectomy is Associated with Lower Incidence of Anemia and Vitamin B12 Deficiency Compared to Total Gastrectomy in Patients with Upper Gastric Cancer.

Purpose: Proximal gastrectomy is an alternative to total gastrectomy (TG) for early gastric cancer (EGC) treatment in the upper stomach. However, its benefits in terms of perioperative and long-term outcomes remain controversial. The aim of this study was to compare the perioperative, body compositional, nutritional, and survival outcomes of patients undergoing proximal gastrectomy with double-tract reconstruction (PG-DTR) and TG for pathological stage I gastric cancer in upper stomach. Materials and Methods: The study included 506 patients who underwent gastrectomy for pathological stage I gastric cancer in the upper stomach between 2015 and 2019. Clinicopathological, perioperative, body compositional, nutritional, and survival outcomes were compared between the PG-DTR and TG groups. Results: The PG-DTR and TG groups included 197 (38.9%) and 309 (61.1%) patients, respectively. The PG-DTR group had a lower rate of early complications (p=0.041), lower diagnosis rate of anemia and vitamin B12 deficiency (all p<0.001), and lower replacement rate of iron and vitamin B12 compared to TG group (all p<0.001). The PG-DTR group showed reduced incidence of sarcopenia at 6-months postoperatively, preserved higher amount of visceral fat after surgery (p=0.032 and p=0.040, respectively), and showed a higher hemoglobin level (p=0.007). Oncologic outcomes were comparable between the groups. Conclusion: The PG-DTR for EGC located in the upper stomach offered advantages of fewer complications, lower incidence of anemia and vitamin B12 deficiency, less decrease in visceral fat volume, and similar survival compared to TG. Consequently, PG-DTR may be considered a superior alternative treatment option to TG.

Photonic crystal-assisted sub-bandgap photocatalysis via triplet-triplet annihilation upconversion for the degradation of environmental organic pollutants.

This study explores novel approaches to enhance photocatalysis efficiency by introducing a photonic crystal (PC)-enhanced, multi-layered sub-bandgap photocatalytic reactor. The design aims to effectively utilize sub-bandgap photons that might otherwise go unused. The device consists of three types of layers: (1) two polymeric triplet-triplet annihilation upconversion (TTA-UC) layers converting low-energy green photons (λEx = 532 nm, 2.33 eV) to high-energy blue photons (λEm = 425 nm, 2.92 eV), (2) a platinum-decorated WO3 layer (Eg = 2.8 eV) serving as a visible-light photocatalyst, and (3) a PC layer optimizing both TTA-UC and photocatalysis. The integration of the PC layer resulted in a 1.9-fold increase in UC emission and a 7.9-fold enhancement in hydroxyl radical (•OH) generation, achieved under low-intensity sub-bandgap irradiation (17.6 mW cm-2). Consequently, the combined layered structure of TTA/Pt-WO3/TTA/PC achieved a remarkable 38.8-fold improvement in •OH production, leading to outstanding degradation capability for various organic pollutants (e.g., 4-chlorophenol, bisphenol A, and methylene blue). This multi-layered sub-bandgap photocatalytic structure, which uniquely combines TTA-UC and PC layers, offers valuable insights into designing efficient photocatalytic systems for future solar-driven environmental remediation.

Oxygen-enriched carbon quantum dots from coffee waste: Extremely active organic photocatalyst for sustainable solar-to-H2O2 conversion.

Solar-driven artificial photosynthesis offers a promising avenue for hydrogen peroxide (H2O2) generation, an efficient and economical replacement for current methods. The efficiency and selectivity hurdles of the two-electron oxygen reduction reaction (ORR) in solar-to- H2O2 conversion are substantial barriers to large scale production. In this manuscript, a simple biomass-assisted synthesis was performed to produce oxygen-enriched carbon quantum dots (OE-CQDs) from spent coffee waste, acting as an efficient photocatalyst for solar-powered H2O2 production. OE-CQDs can stabilize and store light-generated electrons effectively, boosting charge separation and enhancing photocatalytic performance with longevity. The maximal photocatalytic H2O2 production was achieved viz the utilization of OE-CQDs with generation rate of 356.86 µmol g-1 h-1 by retaining 80% activity without any external sacrificial donors. The outstanding performance of synthesized OE-CQDs under light exposure at wavelength (λ) of 280 nm has been ensured by the quantum yield value of 9.4% upon H2O2 generation. The combinatorial benefits of OE-CQDs with their authentic crystalline structure and oxygen enrichment, is expected to be enhancing the ORR activity through accelerating charge transfer, and optimizing oxygen diffusion. Consequently, our eco-friendly method holds considerable promise for creating highly efficient, metal-free photocatalysts for artificial H2O2 production.

Predicting peritoneal recurrence after radical gastrectomy for gastric cancer: Validation of a prediction model (PERI-Gastric 1 and PERI-Gastric 2) on a Korean database.

BACKGROUND: Peritoneal recurrence is a significant cause of treatment failure after radical gastrectomy for gastric cancer. The prediction of metachronous peritoneal recurrence would have a significantly impact risk stratification and tailored treatment planning. This study aimed to externally validate the previously established PERI-Gastric 1 and 2 models to assess their generalizability in an independent population. METHODS: Retrospective external validation was conducted on a cohort of 8564 patients who underwent elective gastrectomy for stage Ib-IIIc gastric cancer between 1998 and 2018 at the Yonsei Cancer Center. Discrimination was tested using the area under the receiver operating characteristic curves (AUROC). Accuracy was tested by plotting observations against the predicted risk of peritoneal recurrence and analyzing the resulting calibration plots. Clinical usefulness was tested with a decision curve analysis. RESULTS: In the validation cohort, PERI-Gastric 1 and PERI-Gastric 2 exhibited an AUROC of 0.766 (95 % C.I. 0.752-0.778) and 0.767 (95 % C.I. 0.755-0.780), a calibration-in-the-large of 0.935 and 0.700, a calibration belt with a 95 % C.I. over the bisector in the risk range of 24%-33 % and 35%-47 %. The decision curve analysis revealed a positive net benefit in the risk range of 10%-42 % and 15%-45 %, respectively. CONCLUSIONS: This study presents the external validation of the PERI-Gastric 1 and 2 scores in an Eastern population. The models demonstrated fair discrimination and satisfactory calibration for predicting the risk of peritoneal recurrence after radical gastrectomy, even in Eastern patients. PERI-Gastric 1 and 2 scores could also be applied to predict the risk of metachronous peritoneal recurrence in Eastern populations.

Superior lymph node harvest by fluorescent lymphography during minimally invasive gastrectomy for gastric cancer patients with high body mass index.

BACKGROUND: Fluorescent lymphography (FL) using indocyanine green (ICG) allows for the visualization of all draining lymph nodes (LNs), thereby increasing LN retrieval. However, no studies have assessed the efficacy of FL in high body mass index (BMI) gastric cancer patients, even as LN yield decreases with increasing BMI in gastrectomy. This study aimed to investigate the influence of FL on LN retrieval in high BMI gastric cancer patients. METHODS: Gastric cancer patients who underwent laparoscopic or robotic gastrectomies from 2013 to 2021 were included. Patients were classified into two groups, with FL (FL group) or without FL (non-FL group). The effect of FL on LN retrieval was assessed by BMI. Inverse probability of treatment weighting (IPTW) was used to ensure comparability between groups. RESULTS: Retrieved LN number decreased as BMI increased regardless of FL application (P < 0.001). According to the IPTW analysis, the mean retrieved LN number was significantly higher in the FL group (48.4 ± 18.5) than in the non-FL group (39.8 ± 16.3, P < 0.001), irrespective of BMI. The FL group exhibited a significantly higher proportion of patients with 16 or more LNs (99.5%) than the non-FL group (98.1%, P < 0.001). The FL group also had a significantly higher proportion of patients with 30 or more LNs (86.6%) than the non-FL group (72.2%, P < 0.001). In both the normal and high-BMI patients, the FL group had a significantly larger percentage of patients with a higher nodal classification than the non-FL group. CONCLUSION: FL resulted in more LN retrieval, even in high BMI patients. FL ensures accurate staging by maintaining the appropriate retrieved LN number in high BMI gastric cancer patients.

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.

Housing of electrosynthetic biofilms using a roll-up carbon veil electrode increases CO2 conversion and faradaic efficiency in microbial electrosynthesis cells.

Electrode-driven microbial electron transfer enables the conversion of CO2 into multi-carbon compounds. The electrosynthetic biofilms grow slowly on the surface and are highly susceptible to operational influences, such as hydrodynamic shear stress. In this study, a cylindrical roll-up carbon felt electrode was developed as a novel strategy to protect biofilms from shear stress within the reactor. The fabricated electrode allowed hydrogen bubble formation inside the structure, which enabled microbes to uptake hydrogen and convert CO2 to multi-carbon organic compounds. The roll-up electrode exhibited faster start-up and biofilm formation than the conventional linear shape carbon felt. The acetate yield and cathodic faradaic efficiency increased by 80% and 34%, respectively, and the bioelectrochemical stability was improved significantly. The roll-up structure increased biofilm development per unit electrode surface by three to five-fold. The roll-up configuration improved biofilm formation on the electrode, which enhanced the performance of microbial electrosynthesis-based CO2 valorization.

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.

The Intraoperative Administration of Dexmedetomidine Alleviates Postoperative Inflammatory Response in Patients Undergoing Laparoscopy-Assisted Gastrectomy: A Double-Blind Randomized Controlled Trial.

Surgical stress can compromise the immune system of patients with cancer, affecting susceptibility to perioperative infections, tumor progression, treatment responses, and postoperative recovery. Perioperatively reducing inflammatory responses could improve outcomes. We determined the impact of intraoperative dexmedetomidine administration on the inflammatory response and postoperative recovery in patients undergoing elective laparoscopy-assisted gastrectomy. These patients were randomly assigned to the dexmedetomidine or control group (n = 42 each). The primary endpoint was the C-reactive protein (CRP) level on postoperative day 1. The secondary endpoints included the perioperative interleukin (IL)-6 levels, postoperative numerical rating scale (NRS) scores, and rescue analgesic doses. There were no significant between-group differences in terms of CRP levels. The IL-6 levels at the end of the surgery, NRS scores in the post-anesthesia care unit, and rescue pethidine requirements within the first hour postoperatively were significantly lower in the dexmedetomidine group than in the control group. The bolus deliveries-to-attempts ratio (via patient-controlled analgesia) at 2 h differed significantly between the two groups. However, IL-6 reduction was confined to a single timepoint, and the postoperative analgesic effects lasted for the first 2 h postoperatively. Low-dose dexmedetomidine infusion (0.4 µg kg-1 h-1) during laparoscopy-assisted gastrectomy exerts minimal anti-inflammatory effects.

Impact of Coronavirus Disease 2019 on Gastric Cancer Diagnosis and Stage: A Single-Institute Study in South Korea.

PURPOSE: Gastric cancer (GC) is among the most prevalent and fatal cancers worldwide. National cancer screening programs in countries with high incidences of this disease provide medical aid beneficiaries with free-of-charge screening involving upper endoscopy to detect early-stage GC. However, the coronavirus disease 2019 (COVID-19) pandemic has caused major disruptions to routine healthcare access. Thus, this study aimed to assess the impact of COVID-19 on the diagnosis, overall incidence, and stage distribution of GC. MATERIALS AND METHODS: We identified patients in our hospital cancer registry who were diagnosed with GC between January 2018 and December 2021 and compared the cancer stage at diagnosis before and during the COVID-19 pandemic. Subgroup analyses were conducted according to age and sex. The years 2018 and 2019 were defined as the "before COVID" period, and the years 2020 and 2021 as the "during COVID" period. RESULTS: Overall, 10,875 patients were evaluated; 6,535 and 4,340 patients were diagnosed before and during the COVID-19 period, respectively. The number of diagnoses was lower during the COVID-19 pandemic (189 patients/month vs. 264 patients/month) than before it. Notably, the proportion of patients with stages 3 or 4 GC in 2021 was higher among men and patients aged ≥40 years. CONCLUSIONS: During the COVID-19 pandemic, the overall number of GC diagnoses decreased significantly in a single institute. Moreover, GCs were in more advanced stages at the time of diagnosis. Further studies are required to elucidate the relationship between the COVID-19 pandemic and the delay in the detection of GC worldwide.

Safety and feasibility of reduced-port robotic distal gastrectomy for gastric cancer: a phase I/II clinical trial using the da Vinci Single Port(SP) robotic system.

Minimally invasive surgery reduces surgical trauma and the size and number of incisions. The da Vinci SP robotic surgical system was designed to overcome the technical demands of single-incision laparoscopic surgery. This study aimed to demonstrate the safety and feasibility of single-port (SP) robotic distal gastrectomy (SPRDG) for patients with gastric cancer using the da Vinci SP system (Intuitive Surgical Inc., Sunnyvale, CA, USA). This study was designed as a single-arm prospective phase I/II clinical trial of SPRDG (first posted date: 21/09/2021, NCT05051670; clinicaltrials.gov). SPRDG using the da Vinci SP system was performed on 19 patients with gastric cancer between December 2021 and October 2022. The primary outcome was the safety of SPRDG as measured by major postoperative complications. The secondary outcomes were operation time, bleeding amount, bowel motility recovery, and length of hospital stay. SPRDG was performed in all 19 patients without unexpected events, such as use of additional trocars or conversion to laparoscopic or open surgery. No major complications occurred postoperatively (0/19, 0.0%). The mean operation time was 218 min (range 164-286 min). The mean hospital stay duration was 3.2 days (range 2-4 days). This phase I/II clinical trial, performed by a single expert surgeon, demonstrated the safety and feasibility of SPRDG with the da Vinci SP system in selected patients with gastric cancer. SPRDG could be a reasonable alternative to conventional or reduced-port minimally invasive gastrectomy, as it has cosmetic advantages, early recovery, and safe discharge.

Intracorporeal modified delta-shaped gastroduodenostomy during 2-port distal gastrectomy: technical aspects and short-term outcomes.

Purpose: Surgeons have become increasingly interested in reduced-port gastrectomy to minimize trauma while maintaining oncologic safety. Although gastroduodenostomy has the benefits of better nutritional outcomes and fewer postoperative complications than other types of reconstruction, gastroduodenostomy is not a preferred option for reduced-port distal gastrectomy because of technical difficulties. In this study, we describe our intracorporeal modified delta-shaped gastroduodenostomy technique, which is easily applicable during 2-port distal gastrectomy. Methods: We retrospectively reviewed our database of 30 consecutive patients with gastric cancer who underwent 2-port distal gastrectomy with intracorporeal modified delta-shaped gastroduodenostomy from October 2016 to May 2021. In this reduced-port approach, we used a Tropian Single port (TROPIAN TECH) via a 25-mm transumbilical incision and a 12-mm port at the right flank. All anastomoses were performed using a 60-mm endolinear stapler. We used 3 additional sutures to provide proper traction and support for the anastomosis. Results: Mean ± standard deviation of operation time was 148.9 ± 34.7 minutes; reconstruction time was 13.2 ± 4.6 minutes; estimated blood loss was 29.3 ± 44.4 mL; and length of hospital stay was 4.5 ± 1.2 postoperative days. A total of 11 patients (36.7%) had a Clavien-Dindo grade I or grade II complication, and there were no grade IIIa or higher complications. Conclusion: Intracorporeal modified delta-shaped gastroduodenostomy was safely performed via a 2-port approach, resulting in acceptable surgical outcomes and no major complications.

Fluorescence-guided Two-port Robotic Gastrectomy Versus Conventional Laparoscopic Gastrectomy: A Nonrandomized Controlled Trial.

Objective: To compare the number of retrieved lymph nodes between conventional laparoscopic gastrectomy (CLG) and robotic gastrectomy integrated with fluorescence guidance and a two-port system (integrated robotic gastrectomy, IRG). Background: The benefits of robotic surgery over laparoscopic surgery for gastric cancer have not yet been established. Using built-in features of robotic system, further benefit can be provided to the patients with effective lymphadenectomy and enhanced recovery. Methods: A nonrandomized controlled trial was performed by a single surgeon at single-center, tertiary referral hospital between January 2018 and October 2021. Overall, 140 patients scheduled to undergo minimally invasive subtotal gastrectomy for early gastric cancer were enrolled. The primary endpoint was the number of retrieved lymph nodes. Secondary endpoints were complications, hospital stay, pain score, body image, and operative cost. Results: This study analyzed 124 patients in the per-protocol group (IRG, 64; CLG, 60). The number of retrieved lymph nodes was higher in the IRG group than those in the CLG group (IRG vs CLG; 42.1 ± 17.9 vs 35.1 ± 14.6, P = 0.019). Moreover, other surgical parameters, such as hospital stay (4.1 ± 1.0 vs 5.2 ± 1.8, P < 0.001) and body image scale (better in 4 of the 10 questions), were significantly better in the IRG than in the CLG. Conclusions: Robotic surgical procedures integrated with fluorescence guidance and a reduced-port system yielded more retrieved lymph nodes. In addition, the IRG group showed better perioperative surgical outcomes, particularly regarding the length of hospital stay and postoperative body image. Trial registration: NCT03396354.

Splenic hilar lymph node dissection enhances survival in Bormann type 4 gastric cancer.

Splenic hilar (no.10) lymph node dissection during total gastrectomy is no longer recommended for advanced proximal gastric cancer. However, the treatment efficacy of no.10 lymph node dissection in Borrmann type 4 tumors remains unclear. We enrolled 539 patients who underwent total gastrectomy for Borrmann type 4 tumors between 2006 and 2016 in four major institutions in Korea. We compared the long-term survival of the no.10 lymph node dissection (n = 309) and no-dissection groups (n = 230) using the propensity score (inverse probability of treatment weighting). The treatment effects of no.10 lymph node dissection were estimated in the weighted sample using the Cox proportional hazards regression model with a robust sandwich-type variance estimator. After inverse probability of treatment weighting, there were 540.4 patients in the no.10 lymph node dissection group and 532.7 in the no-dissection group. The two groups showed well-balanced baseline characteristics, including tumor node metastasis stage. The 5-year survival rates in the no.10 lymph node dissection and no-dissection groups were 45.7% and 38.6%, respectively (log-rank p = 0.036, hazard ratio 0.786, 95% confidence interval 0.630-0.982). Multivariate analysis revealed that no.10 lymph node dissection was an independent favorable prognostic factor (adjusted hazard ratio 0.747, 95% confidence interval 0.593-0.940) after adjusting for other prognostic factors. Sensitivity analyses in other inverse probability of treatment weighting models and the propensity score matching model showed similar results. Patients undergoing no.10 lymph node dissection showed improved survival compared to those without. No.10 lymph node dissection is recommended during total gastrectomy for patients with Borrmann type 4 gastric cancer.

Phonozen-mediated photodynamic therapy comparing two wavelengths in a mouse model of peritoneal carcinomatosis.

BACKGROUND: This study assessed the therapeutic efficacy of intraperitoneal photodynamic therapy (PDT) using photosensitizer activation at two different wavelengths, 405 and 664 nm, in a mouse model of peritoneal carcinomatosis. METHODS: The dark and light cytotoxicity of chlorin e6-polyvinylpyrrolidone (Phonozen) were measured in vitro under 402 ± 14 and 670 ± 18 nm LED activation in bioluminescent human gastric cancer cells, MKN45-luc. Cell viability was measured at 6 h after irradiation using the PrestoBlue assay. Corresponding in vivo studies were performed in athymic nude mice by intraperitoneal injection of 1 × 106 MKN45-luc cells. PDT was performed 10 d after tumor induction and comprised intraperitoneal injection of Phonozen followed by light irradiation at 3 h, delivered by a diffusing-tip optical fiber placed in the peritoneal cavity and coupled to a 405 or 664 nm diode laser to deliver a total energy of 50 J (20 mice per cohort). Whole-body bioluminescence imaging was used to track the tumor burden after PDT out to 130 days, and 5 mice in each cohort were sacrificed at 4 h post treatment to measure the acute tumor necrosis. RESULTS: Photosensitizer dose-dependent photocytotoxicity was higher in vitro at 405 than 664 nm. In vivo, PDT reduced the tumor growth rate at both wavelengths, with no statistically significant difference. There was substantial necrosis, and median survival was significantly prolonged at both wavelengths compared with controls (46 and 46 vs. 34 days). CONCLUSIONS: Phonozen-mediated PDT results in significant cytotoxicity in vitro as well as tumor necrosis and prolonged survival in vivo following intraperitoneal light irradiation. Blue light was more photocytotoxic than red in vitro and had marginally higher efficacy in vivo.