Visceral obesity and anastomotic leakage rates in colorectal cancer: a systematic review and meta-analysis

BackgroundNumberous studies have heatedly discussed whether obesity is a risk factor for anastomotic leakage (AL) because of the increasing number of colorectal cancer (CRC) cases and high incidence of CRC in patients with obesity.ObjectiveWe aimed to explore the relationship between visceral obesity(VO) and AL after CRC surgery. The databases of Pubmed, Embase, and the Cochrane Library were searched for relevant data and articles published until November 1, 2022. We identified the difference in the incidence of AL after CRC surgery between patients with and without VO. The quality of included studies was evaluated using the Newcastle- Ottawa Scale, and odds ratio (OR) and 95% CI were used to assess the association between VO and AL.ResultsThis meta-analysis included 7 studies with 2,136 patients. The OR of patients with VO versus those without VO was 2.15 (95%CIs = 1.46–3.15, test for heterogeneity: P = 0.29, I2 = 18%) based on the fixed-effect model in seven studies. Notably, the difference between the two groups was statistically significant (Z = 3.91 P < 0.0001). Patients with VO in the colon cancer group exhibited a higher incidence of AL (OR = 2.88, 95% CIs = 1.38–5.99, test for heterogeneity: P = 0.27, I2 = 20%) than those in the rectal cancer group (OR = 2.74, 95% CIs = 1.13–6.65, test for heterogeneity: P = 0.20, I2 = 38%). In the studies in the relevant literature, heterogeneity was low. Regarding patients with VO, four Asian studies reported increased morbidity due to AL (OR = 2.79, 95% CIs = 1.35–5.78, test for heterogeneity: P = 0.35, I2 = 9%) compared with three non-Asian studies.ConclusionsOur findings confirmed the significant relationship between VO and AL. Thus, VO could be considered a reliable risk factor of surgery for colon cancer

Submicron structure random field on granular soil material with retinex algorithm optimization

In this paper, a Retinex scale optimized image enhancement algorithm is proposed, which can enhance the micro vision image and eliminate the influence of the uneven illumination. Based on that, a random geometric model of the microstructure of granular materials is established with Monte-Carlo method, the numerical simulation including consolidation process of granular materials is compared with the experimental data. The results have proved that the random field method with Retinex image enhancement algorithm is effective, the image of microstructure of granular materials becomes clear and the contrast ratio is improved, after using Retinex image enhancement algorithm to enhance the CT image. The fidelity of enhanced image is higher than that dealing with other method, which have explained that the algorithm can preserve the microstructure information of the image well. The result of numerical simulation is similar with the one obtained from conventional three axis consolidation test, which proves that the simulation result is reliable

Calculation of Soil Deformation Caused by Shield Tunneling through the Sludge Layer with Plastic Drainage Plates

Due to a lack of engineering experience, research on ground deformation during shield machine tunneling in sludge layers is limited, especially in areas with plastic drainage plates installed for ground stabilization. When the shield passes through this area, the shield cutterhead may be jammed by the drainage plates, resulting in excavation surface instability, excess ground deformation, and schedule delay. In this work, a Mindlin solution for ground deformation in such a layer is obtained, considering four factors: the frontal additional pressure generated by the shield cutterhead due to the soil squeezing effect, the uneven lateral friction between the shield shell and the soil, the frontal friction generated by the shield cutterhead when cutting through the drainage plate, and the shield machine restart after shutdown. The results show that the theoretical curve is in good agreement with the measured values. The maximum settlement was approximately 10 m behind the excavation surface, and the maximum uplift was approximately 5 m in front of the excavation surface. The most influential factor among all the studied factors was the additional pressure on the shield cutter, which accounted for approximately 56% of the maximum settlement and 60% of the maximum uplift. The soil settlement mainly occurred within 12 m on both sides of the tunnel axis. The maximum settlements at the different soil depths tested were all directly below the tunnel axis

Risk Analysis and Control Measures for Slurry Shield Tunneling Diagonally under an Urban River Embankment

The construction of urban cross-river tunnels usually requires passing under river embankments, which inevitably disturbs the embankment substratum and causes ground deformation. Previous engineering cases have shown that embankment settlement is greater than ordinary surface settlement and that uneven settlement results in cracks of in the embankment, reducing the embankment stability. Based on a cross-river tunnel project in China, the construction risks caused by the additional stress on the embankment substratum, asymmetrical embankment load, and shield tunneling in saturated fine sand are analyzed during a large-diameter slurry shield tunneling below an urban river embankment diagonally. Additionally, relevant risk control measures, such as slurry pressure, jacking thrust setting, and driving velocity in the saturated fine sand stratum, are evaluated. The results show that during shield tunneling under a diagonal urban river embankment, the additional stress and asymmetrical load effects should be considered, and the shield slurry pressure and jacking thrust should be adjusted according to the distance between the cutter head and the embankment. Furthermore, based on settlement monitoring data, the driving velocity of the shield should be reasonably adjusted in a timely manner to avoid disturbing the fine sand stratum below the embankment

Submicron structure random field on granular soil material with retinex algorithm optimization

In this paper, a Retinex scale optimized image enhancement algorithm is proposed, which can enhance the micro vision image and eliminate the influence of the uneven illumination. Based on that, a random geometric model of the microstructure of granular materials is established with Monte-Carlo method, the numerical simulation including consolidation process of granular materials is compared with the experimental data. The results have proved that the random field method with Retinex image enhancement algorithm is effective, the image of microstructure of granular materials becomes clear and the contrast ratio is improved, after using Retinex image enhancement algorithm to enhance the CT image. The fidelity of enhanced image is higher than that dealing with other method, which have explained that the algorithm can preserve the microstructure information of the image well. The result of numerical simulation is similar with the one obtained from conventional three axis consolidation test, which proves that the simulation result is reliable

Transanal drainage tube for the prevention of anastomotic leakage after rectal cancer surgery: a meta−analysis of randomized controlled trials

BackgroundAnastomotic leakage (AL) is a serious complication of anterior resection for rectal cancer. The use of transanal drainage tubes (TDT) during surgery to prevent AL remains controversial. Therefore, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to determine the efficacy of TDT in reducing AL.MethodsRelevant data and studies published from inception until November 1, 2022, were retrieved from PubMed, Embase, and Cochrane Library databases to compare the incidence of AL after anterior resection for rectal cancer with and without TDT.ResultsThis meta-analysis included 5 RCTs comprising 1385 patients. The results showed that the intraoperative use of TDT could not reduce the incidence of AL after rectal cancer surgery (risk ratio [RR], 0.91; 95% confidence interval [CI], 0.52–1.59; p = 0.75). A subgroup analysis of different degrees of AL revealed that TDT did not reduce the incidence of postoperative grade B AL (RR, 1.18; 95% CI, 0.67–2.09; p = 0.56) but decreased the incidence of grade C AL (RR, 0.28; 95% CI: 0.12–0.64; p = 0.003). Further, TDT did not reduce the incidence of AL in patients with rectal cancer and a stoma (RR, 2.40; 95% CI, 1.01–5.71; p = 0.05).ConclusionTDT were ineffective in reducing the overall incidence of AL, but they might be beneficial in reducing the incidence of grade C AL in patients who underwent anterior resection. However, additional multicenter RCTs with larger sample sizes based on unified control standards and TDT indications are warranted to validate these findings

Impact of sex on treatment-related adverse effects and prognosis in nasopharyngeal carcinoma

Abstract Background In nasopharyngeal cancer (NPC), women have a lower incidence and mortality rate than men. Whether sex influences the prognosis of NPC patients remains debatable. We retrospectively examined the influence of sex on treatment-related side effects and prognosis in NPC. Methods Clinical data of 1,462 patients with NPC treated at the Southern Hospital of Southern Medical University from January 2004 to December 2015 were retrospectively examined. Statistical analysis was performed to assess differences in overall survival (OS), distant metastasis-free survival (DMFS), local recurrence-free survival(LRFS), and progression-free survival(PFS), as well as treatment-related adverse effects, including myelosuppression, gastrointestinal responses, and radiation pharyngitis and dermatitis, between men and women. Results Women had better 5-year OS (81.5% vs. 87.1%, P = 0.032) and DMFS (76.2% vs. 83.9%, P = 0.004) than men. Analysis by age showed that the prognoses of premenopausal and menopausal women were better than those of men, whereas prognoses of postmenopausal women and men were not significantly different. Additionally, women had a better prognosis when stratified by treatment regimen. Furthermore, chemotherapy-related adverse effects were more severe in women than in men; however, the incidences of radiation laryngitis and dermatitis were not significantly different between the sexes. Logistic regression analysis revealed that the female sex was an independent risk factor for severe myelosuppression and gastrointestinal reactions. Conclusions Chemotherapy-related side effects are more severe but the overall prognosis is better in women with NPC than in men with NPC. Patients may benefit from a personalized treatment approach for NPC. Trial registration This study was approved by the Medical Ethics Committee of Nanfang Hospital of the Southern Medical University (NFEC-201,710-K3)