Impact of preoperative therapy on surgical outcomes of laparoscopic total gastrectomy for gastric/gastroesophageal junction cancer

Objective: As laparoscopic surgery is widely applied for primarily treated gastric cancer(GC)/gastroesophageal junction cancer(GEJC) and gains many advantages, the feasibility of laparoscopic total gastrectomy(LTG) for GC/GEJC patients who have received preoperative therapy(PT) has come to the fore. This study aims to analyze the safety and feasibility of LTG after PT for GC/GEJC patients.Methods: We retrospectively analyzed the data of 511 patients with GC/GEJC undergoing LTG, of which 405received LTG(LTG group) and 106 received PT+LTG(PT-LTG group) at Nanfang Hospital between June 2018and September 2022. The surgical outcomes were compared between the two groups.Results: The surgical duration was significantly longer in the PT-LTG group(P<0.001), while the incidence of intraoperative complications(P=1.000), postoperative complications(LTG group vs. PT-LTG group: 26.2% vs.23.6%, P=0.587), the classification of complication severity(P=0.271), and postoperative recovery was similar between two groups. Notably, the incidence of anastomotic complications of esophagojejunostomy was also comparable between the two groups(LTG group vs. PT-LTG group: 5.9% vs. 5.7%, P=0.918). The univariate and multivariate analysis confirmed that positive proximal margin [positive vs. negative: odds ratio(OR)=14.094, 95%confidence interval(95% CI): 2.639-75.260, P=0.002], rather than PT, has an impact on anastomotic complications after LTG(OR=0.945, 95% CI: 0.371-2.408, P=0.905).Conclusions: PT did not increase the surgical risk of LTG for GC/GEJC. Therefore, considering the positive effect of PT on long-term survival, the broader application of PT and LTG for GC/GEJC is supported by our findings.

Laparoscopic distal gastrectomy with D2 dissection for advanced gastric cancer

The successful application of the laparoscopic distal gastrectomy with D2 dissection for gastric cancer requires adequate understanding of the anatomic characteristics of peripancreatic and intrathecal spaces, the role of pancreas and vascular bifurcation as the surgical landmarks, as well as the variations of gastric vascular anatomy. The standardized surgical procedures based on distribution of regional lymph node should be clarified.

Impact of diabetes on prognosis of gastric cancer patients performed with gastrectomy

Objective: This study aimed to determine the impact of type 2 diabetes mellitus(T2 DM) on clinical outcomes of gastric cancer(GC) patients and explore whether metformin use and good glycemic control could reverse it.Methods: Clinicopathologic data of consecutive GC patients who underwent gastrectomy at Nanfang Hospital between October 2004 and December 2015 were included. Propensity score matching(PSM) was performed to balance the important factors of the disease status between non-T2 DM and T2 DM group. The last follow-up time was January 2019.Results: A total of 1,692 eligible patients(1,621 non-T2 DM vs. 71 T2 DM) were included. After PSM, nonT2 DM group(n=139) and T2 DM group(n=71) were more balanced in baseline variables. The 5-year cancerspecific survival(CSS) rate in T2 DM group(47.0%) was inferior to that in non-T2 DM group(58.0%), but did not reach statistical significance [hazard ratio(HR)=1.319, 95% confidence interval(95% CI): 0.868-2.005, P=0.192].While the 5-year progress-free survival(PFS) rate of T2 DM group(40.6%) is significantly worse than that in nonT2 DM group(56.3%)(HR=1.516, 95% CI: 1.004-2.290, P=0.045). Univariate and multivariate analyses showed that T2 DM was an independent risk factor for PFS but not for CSS. In T2 DM group, metformin use subgroup was associated with superior 5-year CSS and PFS in compared with non-metformin use subgroup, although the difference was not statistically significant(5-year CSS: 48.0% vs. 45.4%, HR=0.680, 95% CI: 0.352-1.313,P=0.246;5-year PFS: 43.5% vs. 35.7%, HR=0.763, 95% CI: 0.400-1.454, P=0.406). The 5-year CSS rate was47.5% in good glycemic control subgroup and 44.1% in poor glycemic control subgroup(HR=0.826, 95% CI:0.398-1.713, P=0.605). And both two subgroups yielded a similar 5-year PFS rate(42.2% vs. 36.3%, HR=0.908,95% CI: 0.441-1.871, P=0.792).Conclusions: DM promoted disease progress of GC after gastrectomy but had not yet led to the significant discrepancy of CSS. For GC patients with T2 DM, metformin use was associated with superior survival but without statistical significance, while better glycemic control could not improve the prognosis.

Experimental study of face passive failure features of a shallow shield tunnel in coastal backfill sand

Face passive failure can severely damage existing structures and underground utilities during shallow shield tunneling,especially in coastal backfill sand.In this work,a series of laboratory model tests were developed and conducted to investigate such failure,for tunnels located at burial depth ratios for which C/D=0.5,0.8,1,and 1.3.Support pressures,the evolution of failure processes,the failure modes,and the distribution of velocity fields were examined through model tests and numerical analyses.The support pressure in the tests first rose rapidly to the elastic limit and then gradually increased to the maximum value in all cases.The maximum support pressure decreased slightly in cases where C/D=0.8,1,and 1.3,but the rebound was insignificant where C/D=0.5.In addition,the configuration of the failure mode with C/D=0.5 showed a wedge-shaped arch,which was determined by the outcropping shear failure.The configuration of failure modes was composed of an arch and the inverted trapezoid when C/D=0.8,1,and 1.3,in which the mode was divided into lower and upper failure zones.

Diabetes mellitus promoted lymph node metastasis in gastric cancer: a 15-year single-institution experience

Background: Previous studies have revealed that diabetes mellitus (DM) promotes disease progress of gastric cancer (GC). This study aimed to further investigating whether DM advanced lymph nodes (LNs) metastasis in GC.Methods: The clinicopathologic data of GC patients with >15 examined LN (ELN) between October 2004 and December 2019 from a prospectively maintained database were included. The observational outcomes included the number (N3b status) and anatomical distribution (N3 stations) of metastatic LN (MLN).Results: A total of 2142 eligible patients were included in the study between October 2004 and December 2019. N3 stations metastasis (26.8% in DMvs. 19.3% in non-DM,P = 0.026) and N3b status (18.8% in DMvs. 12.8% in non-DM,P = 0.039) were more advanced in the DM group, and multivariate logistic regression analyses confirmed that DM was an independent factor of developing N3 stations metastasis (odds ratio [OR] = 1.771,P= 0.011) and N3b status (OR= 1.752,P= 0.028). Also, multivariate analyses determined DM was independently associated with more MLN (β = 1.424,P = 0.047). The preponderance of N3 stations metastasis (DMvs. non-DM, T1-2: 2.2%vs. 4.9%, T3: 29.0%vs. 20.3%, T4a: 38.9%vs. 25.8%, T4b: 50.0%vs. 36.6%;ELN16-29: 8.6%vs. 10.4%, ELN30-44: 27.9%vs. 20.5%, ELN ≥ 45: 37.7%vs. 25.3%), N3b status (DMvs. non-DM, T1-2: 0%vs. 1.7%, T3: 16.1%vs. 5.1%, T4a: 27.8%vs. 19.1%, T4b: 44.0%vs. 28.0%;ELN16-29: 8.6%vs. 7.9%, ELN30-44: 18.0%vs. 11.8%, ELN ≥ 45: 26.4%vs. 17.3%), and the number of MLN (DMvs. non-DM, T1-2: 0.4vs. 1.1, T3: 8.6vs. 5.2, T4a: 9.7vs. 8.6, T4b: 17.0vs. 12.8;ELN16-29: 3.6vs. 4.6, ELN30-44: 5.8vs. 5.5, ELN ≥ 45: 12.0vs. 7.7) of DM group increased with the advancement of primary tumor depth stage and raising of ELN.Conclusions: DM was an independent risk factor for promoting LN metastasis. The preponderance of LN involvement in the DM group was aggravated with the advancement of tumor depth.