Minimally invasive surgery for gastric cancer: A comparison between robotic, laparoscopic and open surgery

AIM To investigate the role of minimally invasive surgery for gastric cancer and determine surgical, clinical, and oncological outcomes.METHODS This is a propensity score-matched case-control study, comparing three treatment arms: robotic gastrectomy(RG), laparoscopic gastrectomy(LG), open gastrectomy(OG). Data collection started after sharing a specific study protocol. Data were recorded through a tailored and protected web-based system. Primary outcomes: harvested lymph nodes, estimated blood loss, hospital stay, complications rate. Among the secondary outcomes, there are: operative time, R0 resections, POD of mobilization, POD of starting liquid diet and soft solid diet. The analysis includes the evaluation of type and grade of postoperative complications. Detailed information of anastomotic leakages is also provided.RESULTS The present analysis was carried out of 1026 gastrectomies. To guarantee homogenous distribution of cases, patients in the RG, LG and OG groups were 1:1:2 matched using a propensity score analysis with a caliper = 0.2. The successful matching resulted in a total sample of 604 patients(RG = 151; LG = 151; OG = 302). The three groups showed no differences in all baseline patients characteristics, type of surgery(P = 0.42) and stage of the disease(P = 0.16). Intraoperative blood loss was significantly lower in the LG(95.93 ± 119.22) and RG(117.91 ± 68.11) groups compared to the OG(127.26 ± 79.50, P = 0.002). The mean number of retrieved lymph nodes was similar between the RG(27.78 ± 11.45), LG(24.58 ± 13.56) and OG(25.82 ± 12.07) approach. A benefit in favor of the minimally invasive approaches was found in the length of hospital stay(P < 0.0001). A similar complications rate was found(P = 0.13). The leakage rate was not different(P = 0.78) between groups.CONCLUSION Laparoscopic and robotic surgery can be safely performed and proposed as possible alternative to open surgery. The main highlighted benefit is a faster postoperative functional recovery.

Effects of aging treatment and heat input on the microstructures and mechanical properties of TIG-welded 6061-T6 alloy joints

Aging treatment and various heat input conditions and mechanical properties of TIG welded 606I-T6 alloy joints were adopted to investigate the microstructural evolution by microstructural observations, microhardness tests, and tensile tests. With an increase in heat input, the width of the heat-affected zone （HAZ） increases and grains in the fusion zone （FZ） coarsen. Moreover, the hardness of the HAZ decreases, whereas that of the FZ decreases initially and then increases with an increase in heat input. Low heat input results in the low ultimate tensile strength of the welded joints due to the presence of partial penetrations and pores in the welded joints. After a simple artificial aging treatment at 175℃ for 8 h, the microstructure of the welded joints changes slightly. The mechanical properties of the welded joints enhance significantly after the aging process as few precipitates distribute in the welded seam.

Effect of intensive vs conventional insulin therapy on perioperative nutritional substrates metabolism in patients undergoing gastrectomy

AIM: To investigate the effect of intensive vs conventional insulin therapy on perioperative nutritional substrates metabolism in patients undergoing radical distal gastrectomy. METHODS: Within 24 h of intensive care unit management, patients with gastric cancer were enrolled after written informed consent and randomized to the intensive insulin therapy (IIT) group to keep glucose levels from 4.4 to 6.1 mmol/L or the conventional insulin therapy (CIT) group to keep levels less than 10 mmol/L. Resting energy expenditure (REE), respiratory quotient (RQ), resting energy expenditure per kilogram (REE/kg), and the lipid oxidation rate were monitored by the indirect calorimeter of calcium citrate malate nutrition metabolism investigation system. The changes in body composition were analyzed by multi-frequency bioimpedance analysis. Blood fasting glucose and insulin concentration were measured for assessment of Homeostasis model assessment of insulin resistance. RESULTS: Sixty patients were enrolled. Compared with preoperative baseline, postoperative REE increased by over 22.15% and 11.07%; REE/kg rose up to 27.22 ± 1.33 kcal/kg and 24.72 ± 1.43 kcal/kg; RQ decreased to 0.759 ± 0.034 and 0.791 ± 0.037; the lipid oxidation ratio was up to 78.25% ± 17.74% and 67.13% ± 12.76% supported by parenteral nutrition solutions from 37.56% ± 11.64% at the baseline; the level of Ln-HOMA-IR went up dramatically (P < 0.05, respectively) on postoperative days 1 and 3 in the IIT group. Meanwhile the concentration of total protein, albumin and triglyceride declined significantly on postoperative days 1 and 3 compared with pre-operative levels (P < 0.05, respectively). Compared with the CIT group, IIT reduced the REE/kg level (27.22 ± 1.33 kcal/kg vs 29.97 ± 1.47 kcal/kg, P = 0.008; 24.72 ± 1.43 kcal/kg vs 25.66 ± 1.63 kcal/kg, P = 0.013); and decreased the Ln-HOMA-IR score (P = 0.019, 0.028) on postoperative days 1 and 3; IIT decreased the level of CRP on postoperative days 1 and 3 (P = 0.017, 0.006); the total protein and albumin concentrations in the IIT group were greater than those in the CIT group (P = 0.023, 0.009). Postoperative values of internal cell fluid (ICF), fat mass, protein mass (PM), muscle mass, free fat mass and body weight decreased obviously on postoperative 7th day compared with the preoperative baseline in the CIT group (P < 0.05, respectively). IIT reduced markedly consumption of fat mass, PM and ICF compared with CIT (P = 0.009 to 0.026). CONCLUSION: There were some benefits of IIT in decreasing the perioperative insulin resistance state, reducing energy expenditure and consumption of proteins and lipids tissue in patients undergoing gastrectomy.

Short- and long-term outcomes associated with enhanced recovery after surgery protocol vs conventional management in patients undergoing laparoscopic gastrectomy

BACKGROUND At present,the enhanced recovery after surgery(ERAS)protocol is widely implemented in the field of gastric surgery.However,the effect of the ERAS protocol on the long-term prognosis of gastric cancer has not been reported.AIM To compare the effects of ERAS and conventional protocols on short-term outcomes and long-term prognosis after laparoscopic gastrectomy.METHODS We retrospectively analyzed the data of 1026 consecutive patients who underwent laparoscopic gastrectomy between 2012 and 2015.The patients were divided into either an ERAS group or a conventional group.The groups were matched in a 1:1 ratio using propensity scores based on covariates that affect cancer survival.The primary outcomes were the 5-year overall and cancer-specific survival rates.The secondary outcomes were the postoperative short-term outcomes and inflammatory indexes.RESULTS The patient demographics and baseline characteristics were similar between the two groups after matching.Compared to the conventional group,the ERAS group had a significantly shorter postoperative hospital day(7.09 d vs 8.67 d,P<0.001),shorter time to first flatus,liquid intake,and ambulation(2.50 d vs 3.40 d,P<0.001;1.02 d vs 3.64 d,P<0.001;1.47 d vs 2.99 d,P<0.001,respectively),and lower medical costs($7621.75 vs$7814.16,P=0.009).There was a significantly higher rate of postoperative complications among patients in the conventional group than among those in the ERAS group(18.1 vs 12.3,P=0.030).Regarding inflammatory indexes,the C-reactive protein and procalcitonin levels on postoperative day 3/4 were significantly different between the two groups(P<0.001 and P=0.025,respectively).The ERAS protocol was associated with significantly improved 5-year overall survival and cancer-specific survival rates compared with conventional protocol(P=0.013 and 0.032,respectively).When stratified by tumour stage,only the survival of patients with stage III disease was significantly different between the two groups(P=0.044).CONCLUSION Adherence to the ERAS protocol improves both the short-term outcomes and the 5-year overall survival and cancer-specific survival of patients after laparoscopic gastrectomy.

Promotion of Sema4D expression by tumor-associated macrophages: Significance in gastric carcinoma

AIM To study the role of semaphorin 4 D(Sema4 D) expression promoted by tumor-associated macrophages(TAMs) in gastric carcinoma cells and its clinical significance in the invasion and metastasis of gastric carcinoma.METHODS CD68 and Sema4 D expression was analyzed in gastric carcinoma and adjacent normal tissues from 290 patients using the immunohistochemical streptavidinperoxidase method, and their relationships with clinicopathological features were evaluated. Human M2 macrophages were induced in vitro and co-cultured in non-contact with gastric carcinoma SGC-7901 cells. Changes in the secretory Sema4 D level in the SGC-7901 cell supernatant were measured using an enzymelinked immunosorbent assay. The effects of TAMs on SGC-7901 cell invasion and migration were assessed with invasion and migration assays, respectively.RESULTS CD68 and Sema4 D protein expression was significantly higher in gastric carcinoma tissues than in adjacent normal tissues(71.7% vs 33.8% and 74.5% vs 42.8%, respectively; P < 0.01). CD68 and Sema4 D protein expression was significantly associated with histological differentiation, TNM stage, and lymph node metastasis(P < 0.05), and their expression levels were positively correlated with one another(r = 0.467, P < 0.01). In the in vitro experiment, secretory Sema4 D protein expression was significantly increased in the supernatant of SGC-7901 cells co-cultured with TAMs compared with the blank control(1224.13 ± 29.43 vs 637.15 ± 33.84, P < 0.01). Cell invasion and metastasis were enhanced in the Transwell invasion and migration assays(P < 0.01).CONCLUSION TAMs promote the invasion and metastasis of gastric carcinoma cells possibly through upregulated secretory Sema4 D protein expression. Combined detection of TAM markers, CD68 and Sema4 D, in gastric carcinoma tissue shows potential to predict the trend of gastric carcinoma progression.