Robotic versus laparoscopic gastrectomy for gastric cancer: A Western propensity score matched analysis.

BACKGROUND: Robot-assisted gastrectomy (RG) has been shown to be safe and feasible in the treatment of gastric cancer (GC). However, it is unclear whether RG is equivalent to laparoscopic gastrectomy (LG), especially in the Western world. Our objective was to compare the outcomes of RG and LG in GC patients. METHODS: We reviewed all gastric adenocarcinoma patients who underwent curative gastrectomy by minimally invasive approach in our institution from 2009 to 2022. Propensity score matching (PSM) analysis was conducted to reduce selection bias. DaVinci Si platform was used for RG. RESULTS: A total of 156 patients were eligible for inclusion (48 RG and 108 LG). Total gastrectomy was performed in 21.3% and 25% of cases in LG and RG, respectively. The frequency of stage pTNM II/III was 48.1%, and 54.2% in the LG and RG groups (p = 0.488). After PSM, 48 patients were matched in each group. LG and RG had a similar number of dissected lymph nodes (p = 0.759), operative time (p = 0.421), and hospital stay (p = 0.353). Blood loss was lower in the RG group (p = 0.042). The major postoperative complications rate was 16.7% for LG and 6.2% for RG (p = 0.109). The 30-day mortality rate was 2.1% and 0% for LG and RG, respectively (p = 1.0). There was no significant difference between the LG and RG groups for disease-free survival (79.6% vs. 61.2%, respectively; p = 0.155) and overall survival (75.9% vs. 65.7%, respectively; p = 0.422). CONCLUSION: RG had similar surgical and long-term outcomes compared to LG, with less blood loss observed in RG.

Polyphosphates can stabilize but also aggregate colloids.

Phosphates are well known as dispersants for a variety of colloidal particles. Here however we use rheological measurements to show that high molecular weight polyphosphates (PP) can instead act as a flocculant for LAPONITE® clay platelets. The proposed mechanism is bridging of PP between clay particle edges, leading to highly charged clusters forming a Wigner glass. Dynamic light scattering shows a bimodal cluster size distribution, independent of PP molecular weight, but the highest molecular weight gave the highest viscous and loss moduli for the PP-clay solid. These unique all-inorganic solids may have application in solid-state ionic conducting materials, controlled release fertilizers and biomedical applications.

The Impact of Polyphosphates on the Colloidal Stability of Laponite Particles.

The effect of polyphosphate (polyP) adsorption on the colloidal properties of disc-shaped laponite (LRD) particles was examined in aqueous dispersions with a focus on elucidating the interparticle forces that govern the colloidal stability of the systems. The charge and aggregation rate data of bare LRD exhibited an ionic strength-dependent trend, confirming the presence of double-layer repulsion and van der Waals attraction as major surface interactions. The charge of LRD particles significantly increased in magnitude at elevated polyP concentrations as a result of polyP adsorption and subsequent overcharging of the positively charged sites on the edges of the LRD discs. A transition from stable to unstable LRD colloids was observed with increasing polyP doses indicating the formation of aggregates in the latter systems due to depletion forces and/or bridging interactions induced by dissolved or adsorbed polyP, respectively. The degree of phosphate polymerization influenced neither the charge nor the aggregation mechanism. The findings clearly confirm that polyP adsorption was the driving phenomenon to induce particle aggregation in contrast to other clay types, where phosphate derivatives act as dispersion stabilizing agents. This study provides valuable insights into the early stages of aggregation in colloidal systems involving LRD and polyPs, which have a crucial role in predicting further material properties that are important to designing LRD-polyP composites for applications such as potential phosphate sources in chemical fertilizers.

Gastric partitioning for the treatment of malignant gastric outlet obstruction.

BACKGROUND: Gastric outlet obstruction (GOO) is one of the main complications in stage IV gastric cancer patients. This condition is usually managed by gastrojejunostomy (GJ). However, gastric partitioning (GP) has been described as an alternative to overcoming possible drawbacks of GJ, such as delayed gastric emptying and tumor bleeding. AIM: To compare the outcomes of patients who underwent GP and GJ for malignant GOO. METHODS: We retrospectively analyzed 60 patients who underwent palliative gastric bypass for unresectable distal gastric cancer with GOO from 2009 to 2018. Baseline clinicopathological characteristics including age, nutritional status, body mass index, and performance status were evaluated. Obstructive symptoms were graded according to GOO score (GOOS). Surgical outcomes evaluated included duration of the procedure, surgical complications, mortality, and length of hospital stay. Acceptance of oral diet after the procedure, weight gain, and overall survival were the long-term outcomes evaluated. RESULTS: GP was performed in 30 patients and conventional GJ in the other 30 patients. The mean follow-up was 9.2 mo. Forty-nine (81.6%) patients died during that period. All variables were similar between groups, with the exception of worse performance status in GP patients. The mean operative time was higher in the GP group (161.2 vs 85.2 min, P < 0.001). There were no differences in postoperative complications and surgical mortality between groups. The median overall survival was 7 and 8.4 mo for the GP and GJ groups, respectively (P = 0.610). The oral acceptance of soft solids (GOOS 2) and low residue or full diet (GOOS 3) were reached by 28 (93.3%) GP patients and 22 (75.9%) GJ patients (P = 0.080). Multivariate analysis demonstrated that GOOS 2 and GOOS 3 were the main prognostic factors for survival (hazard ratio: 8.90, 95% confidence interval: 3.38-23.43, P < 0.001). CONCLUSION: GP is a safe and effective procedure to treat GOO. Compared to GJ, it provides similar surgical outcomes with a trend to better solid diet acceptance by patients.

Management of postoperative complications of lymphadenectomy.

Gastric cancer remains a disease with poor prognosis, mainly due to its late diagnosis. Surgery remains as the only treatment with curative intent, where the goal is radical resection with free-margin gastrectomy and extended lymphadenectomy. Over the last two decades there has been an improvement on postoperative outcomes. However, complications rate is still not negligible even in high volume specialized centers and are directly related mainly to the type of gastric resection: total or subtotal, combined with adjacent organs resection and the extension of lymphadenectomy (D1, D2 and D3). The aim of this study is to analyze the complications specific-related to lymphadenectomy in gastric cancer surgery.