BackgroundA generally acceptable definition and a severity grading system for anastomotic leakages (ALs) following rectal resection were not available until 2010, when the International Study Group of Rectal Cancer (ISGRC) proposed a definition and a grading system for AL.MethodsA search for published data was performed using the MEDLINE database (2000 to December 5, 2012) to perform a systematic review of the studies that described AL, grade AL according to the grading system, pool data, and determine the average rate of AL for each grade after anterior resection (AR) for rectal cancer.ResultsA total of 930 abstracts were retrieved; 40 articles on AR, 25 articles on low AR (LAR), and 5 articles on ultralow AR (ULAR) were included in the review and analysis. The pooled overall AL rate of AR was 8.58% (2,085/24,288); the rate of the asymptomatic leakage (Grade A) was 2.57%, that of AL that required active intervention without relaparotomy (Grade B) was 2.37%, and that of AL that required relaparotomy (Grade C) was 5.40%. The pooled rate of AL that required relaparotomy was higher in AR (5.40%) than in LAR (4.70%) and in ULAR (1.81%), which could be attributed to the higher rate of protective defunctioning stoma in LAR (40.72%) and ULAR (63.44%) compared with that in AR (30.11%).ConclusionsThe new grading system is simple that the ALs of each grade can be easily extracted from past publications, therefore likely to be accepted and applied in future studies.

Reduced graphene oxide (rGO) has numerous potential applications, such as molecular sensor, gas separation membrane, etc. The performance of these devices is often subject to the environment humidity due to the interaction of rGO with water. However, the atomically detailed information on the dynamical and thermodynamic properties of water on the surface of graphene-based materials as well as its underlying molecular mechanism is largely unknown. By performing neutron scattering on hydrated rGO powders, composed by well separated monolayer and few-layer rGO sheets, we found three components of surface water. One remains liquid at −80 °C, while the other two freeze into ice in a stepwise manner above −40 °C. Although slightly slower than the other two, the nonfreezing water diffuses an order of magnitude faster on rGO than those confined in the hydrophilic bulk phase, such as compact powder or membrane. Complementary molecular dynamics simulation revealed that the heterogeneity of surface water arises from the gradual attenuation of the electrostatic interaction between water and oxide groups on rGO within a few hydration layers. These findings are fundamental for understanding of interfacial hydration and ice formation in many materials, and valuable for various applications using graphene-based materials.

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Background Anastomotic leakage (AL) is one of most severe postoperative complications following low anterior resection (LAR) for rectal cancer, and has an adverse impact on postoperative recovery. The occurence of AL is associated with several factors, while few studies explored the role of intracorporeal barbed suture reinforcement in it. Methods Consecutive cases underwent laparoscopic LAR for rectal cancer from Mar. 2018 to Feb. 2021 in our center were retrospectively collected. Cases were classified into the intracorporeal barbed suture reinforcement group and the control group according to whether performing intracorporeal reinforcement with barbed suture, and AL incidences were compared between two groups. Propensity score matching (PSM) was then performed based on identified risk factors to reduce biases from covariates between two groups. AL incidences in the matched cohort were compared. Results A total of 292 cases entered into the study, and AL incidences were significantly lower in the intracorporeal barbed suture reinforcement group compared with the control group (10.00% vs 2.82%, P = 0.024). Sex, BMI, preoperative adjuvant chemoradiotherapy and anastomotic level were chose for PSM analyses based on previous studies. In the matched cohort, the AL incidences were still significantly lower in the intracorporeal barbed suture reinforcement group (10.57% vs 2.44%, SD = 0.334). Conclusions Intracorporeal barbed suture reinforcement is associated with low AL incidences after laparoscopic LAR for rectal cancer, which is a potential procedure for reducing AL and worthy of application clinically.