Construction and validation of a risk-prediction model for anastomotic leakage after radical gastrectomy: A cohort study in China

Objectives:Anastomotic leakage(AL)stands out as a prevalent and severe complication following gastric cancer surgery.It frequently precipitates additional serious complications,significantly influencing the overall survival time of patients.This study aims to enhance the risk-assessment strategy for AL following gastrectomy for gastric cancer.Methods:This study included a derivation cohort and validation cohort.The derivation cohort included patients who underwent radical gastrectomy at Sir Run Run Shaw Hospital,Zhejiang University School of Medicine,from January 1,2015 to December 31,2020.An evidence-based predictor questionnaire was crafted through extensive literature review and panel discussions.Based on the questionnaire,inpatient data were collected to form a model-derivation cohort.This cohort underwent both univariate and multivariate analyses to identify factors associated with AL events,and a logistic regression model with stepwise regression was developed.A 5-fold cross-validation ensured model reliability.The validation cohort included patients from August 1,2021 to December 31,2021 at the same hospital.Using the same imputation method,we organized the validation-queue data.We then employed the risk-prediction model constructed in the earlier phase of the study to predict the risk of AL in the subjects included in the validation queue.We compared the predictions with the actual occurrence,and evaluated the external validation performance of the model using model-evaluation indicators such as the area under the receiver operating characteristic curve(AUROC),Brier score,and calibration curve.Results:The derivation cohort included 1377 patients,and the validation cohort included 131 patients.The independent predictors of AL after radical gastrectomy included age65 y,preoperative albumin<35 g/L,resection extent,operative time240 min,and intraoperative blood loss90 mL.The predictive model exhibited a solid AUROC of 0.750(95%CI:0.694e0.806;p<0.001)with a Brier score of 0.049.The 5-fold cross-validation confirmed these findings with a calibrated C-index of 0.749 and an average Brier score of 0.052.External validation showed an AUROC of 0.723(95%CI:0.564e0.882;p?0.006)and a Brier score of 0.055,confirming reliability in different clinical settings.Conclusions:We successfully developed a risk-prediction model for AL following radical gastrectomy.This tool will aid healthcare professionals in anticipating AL,potentially reducing unnecessary interventions.

Endoscopic ultrasound-guided tissue sampling induced pancreatic duct leak resolved by the placement of a pancreatic stent:A case report

BACKGROUND Pancreatic ductal leaks complicated by endoscopic ultrasonography-guided tissue sampling(EUS-TS)can manifest as acute pancreatitis.CASE SUMMARY A 63-year-old man presented with persistent abdominal pain and weight loss.Diagnosis:Laboratory findings revealed elevated carbohydrate antigen 19-9(5920 U/mL)and carcinoembryonic antigen(23.7 ng/mL)levels.Magnetic resonance imaging of the pancreas revealed an approximately 3 cm ill-defined space-occupying lesion in the inferior aspect of the head,with severe encasement of the superior mesenteric artery.Pancreatic ductal adenocarcinoma was confirmed after pathological examination of specimens obtained by EUS-TS using the fanning method.Interventions and outcomes:The following day,the patient experienced severe abdominal pain with high amylase(265 U/L)and lipase(1173 U/L)levels.Computed tomography of the abdomen revealed edematous wall thickening of the second portion of the duodenum with adjacent fluid collections and a suspicious leak from either the distal common bile duct or the main pancreatic duct in the head.Endoscopic retrograde cholangiopancreatography revealed dye leakage in the head of the main pancreatic duct.Therefore,a 5F 7 cm linear plastic stent was deployed into the pancreatic duct to divert the pancreatic juice.The patient’s abdominal pain improved immediately after pancreatic stent insertion,and amylase and lipase levels normalized within a week.Neoadjuvant chemotherapy was then initiated.CONCLUSION Using the fanning method in EUS-TS can inadvertently cause damage to the pancreatic duct and may lead to clinically significant pancreatitis.Placing a pancreatic stent may immediately resolve acute pancreatitis and shorten the waiting time for curative therapy.When using the fanning method during EUSTS,ductal structures should be excluded to prevent pancreatic ductal leakage.

Impact of open hepatectomy on postoperative bile leakage in patients with biliary tract cancer

BACKGROUND Bile leakage is a common and serious complication of open hepatectomy for the treatment of biliary tract cancer.AIM To evaluate the incidence,risk factors,and management of bile leakage after open hepatectomy in patients with biliary tract cancer.METHODS We retrospectively analyzed 120 patients who underwent open hepatectomy for biliary tract cancer from February 2018 to February 2023.Bile leak was defined as bile drainage from the surgical site or drain or the presence of a biloma on imaging.The incidence,severity,timing,location,and treatment of the bile leaks were recorded.The risk factors for bile leakage were analyzed using univariate and multivariate logistic regression analyses.RESULTS The incidence of bile leak was 16.7%(20/120),and most cases were grade A(75%,15/20)according to the International Study Group of Liver Surgery classification.The median time of onset was 5 d(range,1-14 d),and the median duration was 7 d(range,2-28 d).The most common location of bile leakage was the cut surface of the liver(70%,14/20),followed by the anastomosis site(25%,5/20)and the cystic duct stump(5%,1/20).Most bile leaks were treated conservatively with drainage,antibiotics,and nutritional support(85%,17/20),whereas some required endoscopic retrograde cholangiopancreatography with stenting(10%,2/20)or percutaneous transhepatic cholangiography with drainage(5%,1/20).Risk factors for bile leakage include male sex,hepatocellular carcinoma,major hepatectomy,blood loss,and blood transfusion.CONCLUSION Bile leakage is a frequent complication of open hepatectomy for biliary tract cancer.However,most cases are mild and can be conservatively managed.Male sex,hepatocellular carcinoma,major hepatectomy,blood loss,and blood transfusion were associated with an increased risk of bile leak.

Preoperative neutrophil-to-lymphocyte ratio predicts symptomatic anastomotic leakage in elderly colon cancer patients: Multicenter propensity score-matched analysis

BACKGROUND The neutrophil-to-lymphocyte ratio(NLR),a composite inflammatory biomarker,is associated with the prognosis in patients with colorectal tumors.However,whether the NLR can be used as a predictor of symptomatic postoperative ana-stomotic leakage(AL)in elderly patients with colon cancer is unclear.AIM To assess the role of the NLR in predicting the occurrence of symptomatic AL after surgery in elderly patients with colon cancer.METHODS Data from elderly colon cancer patients who underwent elective radical colectomy with anastomosis at three centers between 2018 and 2022 were retrospectively analyzed.Receiver operating characteristic curve analysis was performed to determine the best predictive cutoff value for the NLR.Twenty-two covariates were matched using a 1:1 propensity score matching method,and univariate and multivariate logistic regression analyses were used to determine risk factors for the development of postoperative AL.RESULTS Of the 577 patients included,36(6.2%)had symptomatic AL.The optimal cutoff value of the NLR for predicting AL was 2.66.After propensity score matching,the incidence of AL was significantly greater in the≥2.66 NLR subgroup than in the<2.66 NLR subgroup(11.5%vs 2.5%;P=0.012).Univariate logistic regression analysis revealed statistically significant correlations between blood transfusion intraoperatively and within 2 d postoper-atively,preoperative albumin concentration,preoperative prognostic nutritional index,and preoperative NLR and AL occurrence(P<0.05);multivariate logistic regression analysis revealed that an NLR≥2.66[odds ratio(OR)=5.51;95%confidence interval(CI):1.50-20.26;P=0.010]and blood transfusion intraoperatively and within 2 d postoperatively(OR=2.52;95%CI:0.88-7.25;P=0.049)were risk factors for the occurrence of symptomatic AL.CONCLUSION A preoperative NLR≥2.66 and blood transfusion intraoperatively and within 2 d postoperatively are associated with a higher incidence of postoperative symptomatic AL in elderly patients with colon cancer.The preoperative NLR has predictive value for postoperative symptomatic AL after elective surgery in elderly patients with colon cancer.

Research on Leak Location Method of Water Supply Pipeline Based on MVMD

At present,the leakage rate of the water distribution network in China is still high,and the waste of water resources caused by water distribution network leakage is quite serious every year.Therefore,the location of pipeline leakage is of great significance for saving water resources and reducing economic losses.Acoustic emission technology is the most widely used pipeline leak location technology.The traditional non-stationary random signal de-noising method mainly relies on the estimation of noise parameters,ignoring periodic noise and components unrelated to pipeline leakage.Aiming at the above problems,this paper proposes a leak location method for water supply pipelines based on a multivariate variational mode decomposition algorithm.This method combines the two parameters of the energy loss coefficient and the correlation coefficient between adjacent modes,and adaptively determines the decomposition mode number K according to the characteristics of the signal itself.According to the correlation coefficient,the effective component is selected to reconstruct the signal and the cross-correlation time delay is estimated to determine the location of the pipeline leakage point.The experimental results show that this method has higher accuracy than the cross-correlation method based on VMD and the cross-correlation method based on EMD,and the average relative positioning error is less than 2.2%.

Successful outcome of sphincterotomy and 7 French pigtail stent insertion in the management of post-cholecystectomy bile leaks

BACKGROUND:Endoscopic retrograde cholangiopancrea-tography(ERCP)is widely used to manage post-cholecystectomy bile leaks.However,the best endoscopic intervention remains controversial.We investigated the success of a 7 French double pigtail stent following sphincterotomy in the management of such bile leaks. METHODS:Between July 1998 and June 2008,48 patients were referred for ERCP for presumed post-cholecystectomy bile leaks.Leaks were confirmed at ERCP and managed by a combination of sphincterotomy and stent insertion unless contraindicated. RESULTS:Bile duct cannulation was successful in 44(91.7%)patients.A leak of the cystic duct was demonstrated in 19(43.2%)patients,the duct of Luschka in 11(25.0%),and the common hepatic duct in 5 (11.4%).Complete transection of the common bile duct occurred in 4 patients.The remaining patients had no cholangiographic evidence of a leak.Sphincterotomy was performed in 34 patients.A 7 French double pigtail plastic stent was placed in all 35 patients with cholangiographic evidence of a bile leak.No bile leaks were demonstrated at a follow-up of 8-16 weeks and all stents were removed successfully. CONCLUSION:The combination of sphincterotomy and insertion of a 7 French double pigtail stent results in excellent outcomes in the management of post-cholecystectomy bile leaks.

Aesthetic Features of Leaking Windows in Traditional Gardens in South of the Yangtze River

Gardening style in south of the Yangtze River was reviewed, and aesthetic features of local gardens were summarized as full of humanistic connotations, modeling after the nature, graceful and free from vulgarity, refined and refreshing, implying profound significance in detailed designs, integrated virtual and real scenery. On this basis, form and meaning of leaking windows in the gardens were analyzed, and artistic means of designing leaking windows were summarized from the perspectives of leaking through scenery and borrowed scenery, virtual and real scenery, in-motion and in-position scenery.

Choosing the best endoscopic approach for post-bariatric surgical leaks and fistulas:Basic principles and recommendations

Post-surgical leaks and fistulas are the most feared complication of bariatric surgery.They have become more common in clinical practice given the increasing number of these procedures and can be very difficult to treat.These two related conditions must be distinguished and characterized to guide the appropriate treatment.Leak is defined as a transmural defect with communication between the intra and extraluminal compartments,while fistula is defined as an abnormal communication between two epithelialized surfaces.Traditionally,surgical treatment was the preferred approach for leaks and fistulas and was associated with high morbidity with significant mortality rates.However,with the development of novel devices and techniques,endoscopic therapy plays an increasingly essential role in managing these conditions.Early diagnosis and endoscopic therapy initiation after clinical stabilization are crucial to success since clinical success rates are higher for acute leaks and fistulas when compared to late and chronic leaks and fistulas.Several endoscopic techniques are available with different mechanisms of action,including direct closure,covering/diverting or draining.The treatment should be individualized by considering the characteristics of both the patient and the defect.Although there is a lack of high-quality studies to provide standardized treatment algorithms,this narrative review aims to provide a summary of the current scientific evidence and,based on this data and our extensive experience,make recommendations to help choose the best endoscopic approach for the management of post-bariatric surgical leaks and fistulas.

A reliability-oriented genetic algorithm-levenberg marquardt model for leak risk assessment based on time-frequency features

Since leaks in high-pressure pipelines transporting crude oil can cause severe economic losses,a reliable leak risk assessment can assist in developing an effective pipeline maintenance plan and avoiding unexpected incidents.The fast and accurate leak detection methods are essential for maintaining pipeline safety in pipeline reliability engineering.Current oil pipeline leakage signals are insufficient for feature extraction,while the training time for traditional leakage prediction models is too long.A new leak detection method is proposed based on time-frequency features and the Genetic Algorithm-Levenberg Marquardt(GA-LM)classification model for predicting the leakage status of oil pipelines.The signal that has been processed is transformed to the time and frequency domain,allowing full expression of the original signal.The traditional Back Propagation(BP)neural network is optimized by the Genetic Algorithm(GA)and Levenberg Marquardt(LM)algorithms.The results show that the recognition effect of a combined feature parameter is superior to that of a single feature parameter.The Accuracy,Precision,Recall,and F1score of the GA-LM model is 95%,93.5%,96.7%,and 95.1%,respectively,which proves that the GA-LM model has a good predictive effect and excellent stability for positive and negative samples.The proposed GA-LM model can obviously reduce training time and improve recognition efficiency.In addition,considering that a large number of samples are required for model training,a wavelet threshold method is proposed to generate sample data with higher reliability.The research results can provide an effective theoretical and technical reference for the leakage risk assessment of the actual oil pipelines.

Discovery of pockmarks in the Zengmu Basin,southern South China Sea and the implication

The Zengmu Basin located in the shallow water area of the southern South China Sea,is rich in oil and gas resources,within which faults and mud-diapir are developed,but it is unknown whether oil and gas migrate to the seafloor surface.The newly collected multibeam data across the Zengmu Basin reveal a large number of depressions,with depths of 2-4 m,widths of several tens of meters,large distribution range of 1.8-8 km along survey line,up to~50 km,and their backscatter intensity(-26 dB)is much greater than that of the surrounding area(-38 dB).Combined with the developed mud-diapir and fracture structures,and abundant oil and gas resources within this basin,these depressions are presumed to be pockmarks.Furthermore,more than 110 mono-sized small circular pockmarks,with a depth of less than 1 m and a width of 5 m,are observed in an area of less than 0.03 km2,which are not obliterated by sediment infilling with high sedimentation rate,implying an existence of unit-pockmarks that are or recently were active.In addition,seismic profiles across the Zengmu Basin show characterization of upward migration of hydrocarbons,expressed as mud-diapir structures,bright spots in the shallow formation with characteristics of“low frequency increase and high frequency attenuation”.The subbottom profiles show the mud-diapir structures,as well as the gas-bearing blank zones beneath the seafloor.These features suggest large gas leaking and occurrence of large amounts of carbonate nodules on the seafloor.This indicates the complex and variable substrate type in the Zengmu Basin,while the area was once thought to be mainly silty sand and find sand.This is the first report on the discovery of pockmarks in the Zengmu Basin;it will provide basic information for submarine stability and marine engineering in China’s maritime boundaries.

A sutureless technique for securing leaking sclerotomies with viscoelastic substances in 23-gauge microincision vitrectomy surgery

AIM:To introduce and evaluate the clinical efficacy of a new technique,the use of viscoelastic substances(VS)to close leaking sclerotomy in 23G microincision vitrectomy,and to observe its effect on the visual acuity and intraocular pressure(IOP)of patients.METHODS:Patients who underwent 23G vitrectomy in Ningbo Eye Hospital before the use of VS technique(June 2019 to September 2020)and after the use of VS technique(October 2020 to December 2021)were selected as the subjects of this study.The above cases underwent operation by the same surgeon and were retrospectively analyzed.VS technique was used as the alternative to suturing,in which a small amount of VS was injected at the leaking sclerotomy and then gently massaged to confirm leaking sclerotomy closure.RESULTS:A total of 174 eyes were covered in the study,including 84 eyes in the control group(before the use of VS technique)and 90 eyes in the VS technique group.The number of eyes that needed to be sutured decreased considerably from 42.9%in the control group to 3.3%in the VS technique group,and the proportion of subconjunctival hemorrhage at 1-2d after surgery decreased remarkably from 35.7%in the control group to 2.2%in the VS technique group.No substantial differences in the incidence of mean IOP and low IOP were found between 1-2 and 3-20d after surgery in the VS technique group.No major complications associated with VS technique were identified during the study.CONCLUSION:In 23G microincision vitrectomy,VS technique is a safe,simple,and effective method to close leaking sclerotomy.

Negligible Warming Caused by Nord Stream Methane Leaks

Unanticipated sabotage of two underwater pipelines in the Baltic Sea(Nord Stream 1 and 2)happened on 26September 2022.Massive quantities of natural gas,primarily methane,were released into the atmosphere,which lasted for about one week.As a more powerful greenhouse gas than CO_(2),the potential climatic impact of methane is a global concern.Using multiple methods and datasets,a recent study reported a relatively accurate magnitude of the leaked methane at 0.22±0.03 million tons(Mt),which was lower than the initial estimate in the immediate aftermath of the event.Under an energy conservation framework used in IPCC AR6,we derived a negligible increase in global surface air temperature of 1.8×10^(-5)℃ in a 20-year time horizon caused by the methane leaks with an upper limit of 0.25 Mt.Although the resultant warming from this methane leak incident was minor,future carbon release from additional Earth system feedbacks,such as thawing permafrost,and its impact on the methane mitigation pathways of the Paris Agreement,warrants investigation.

Progress in the study and treatment of peri-device leak after left atrial appendage closure

For patients with atrial fibrillation with an increased risk of stroke and contraindications to long-term anticoagulation,percutaneous left atrial appendage closure(LAAC)has become an important alternative to long-term oral anticoagulation.Incomplete closure of the LAAC during the procedure leads to faster blood flow in the interstitial space around the device,resulting in peri-device leak(PDL),which is not uncommon.Studies are still inconclusive in determining the incidence,long-term safety,and management of PDL.Therefore,this article reviewed the progress made in the research and treatment of PDL after LAAC.

Surgical treatment of mixed cervical spondylosis with spontaneous cerebrospinal fluid leakage: A case report

BACKGROUND Spontaneous cerebrospinal fluid(CSF)leaks associated with cervical spondylosis are rare.To our knowledge,only a few cases have been reported in which treatment is challenging and varies from case to case.Here,we review the literature and describe the surgical treatment of a 70-year-old woman who presented with a CSF leak due to a cervical spine spur.CASE SUMMARY A 70-year-old female patient who was treated for a cerebral infarction,presented with complains of weakness in the right lower extremity and a feeling of stepping on cotton.The patient underwent regular neck massage and presented with neck and right shoulder pain radiating to the right upper extremity one-month ago.Magnetic resonance imaging showed a strip of leaking cerebrospinal fluid posterior to the C1-4 vertebrae,and computed tomography showed a“sickleshaped”disc prolapse with calcification in C4/5.We chose to perform an anterior cervical discectomy.When the prolapsed C4/5 disc was scraped,clear fluid leakage was observed,and exploration revealed a 1 mm diameter rupture in the anterior aspect of the dura mater,which was compressed continuously with cotton patties,with no significant cerebrospinal fluid leakage after 1 h.CONCLUSION Three months after surgery,the patient was asymptomatic and follow-up imaging demonstrated complete resolution.

Role of ablation therapy in conjunction with surgical resection for neuroendocrine tumors involving the liver

BACKGROUND Resection of hepatic metastasis from neuroendocrine tumors(NETs)improves quality of life and prolongs 5-year survival.Ablation can be utilized with surgery to achieve complete resection.Although several studies report long-term out-comes for patients undergoing ablation,none have explored perioperative effects of ablation in patients with metastatic NETs.AIM To determine if intra-operative ablation during hepatectomy increases risk of ad-verse outcomes such as surgical site infections(SSIs),bleeding,and bile leak.METHODS A retrospective analysis of the hepatectomy National Surgical Quality Impro-vement Program database from 2015-2019 was performed to determine the odds of SSIs,bile leaks,or bleeding in patients undergoing intraoperative ablation when compared to hepatectomy alone.RESULTS Of the 966 patients included in the study,298(30.9%)underwent ablation during hepatectomy.There were 78(11.7%)patients with SSIs in the hepatectomy alone group and 39(13.1%)patients with a SSIs in the hepatectomy with ablation group.Bile leak occurred in 41(6.2%)and 14(4.8%)patients in the two groups,respec-tively;bleeding occurred in 117(17.5%)and 33(11.1%),respectively.After con-trolling for confounding variables,ablation did not increase risk of SSI(P=0.63),bile leak(P=0.34)or bleeding(P=0.07)when compared to patients undergoing resection alone on multivariate analysis.CONCLUSION Intraoperative ablation with hepatic resection for NETs is safe in the perioperative period without significant increased risk of infection,bleeding,or bile leak.Surgeons should utilize this modality when appropriate to a-chieve optimal disease control and outcomes.

Experimental models of high-risk bowel anastomosis in rats:A systematic review

BACKGROUND Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity,that negatively affect the patients’quality of life.Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation.Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features.Despite the advances in experimental protocols and techniques,designing a high-quality study is still challenging for the investigators as there is a plethora of different models used.AIM To review current state of the art for experimental protocols in high-risk anastomosis in rats.METHODS This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.To identify eligible studies,a comprehensive literature search was performed in the electronic databases PubMed(MEDLINE)and Scopus,covering the period from conception until 18 October 2023.RESULTS From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis.Methods of assessing anastomotic healing were extracted and were individually appraised.CONCLUSION Anastomotic healing studies have evolved over the last decades,but the findings are yet to be translated into human studies.There is a need for high-quality,well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.

Trans-Frame Aortic Regurgitation of New-Generation Aortic Bioprosthesis

A widely used aortic valve bioprosthesis is susceptible to regurgitation between the sewing ring and the frame of the valve due to its relatively thin fabric coverage. In some cases this leak has been shown to resolve with administration of protamine, however, tension on this area from annular sutures placed in an asymmetric bicuspid valve annulus may exacerbate the defect.

基于LEAK软件对液氯制取系统中装置泄漏概率的预测研究

氯碱厂液氯制取系统是一个密封性的循环系统,循环介质为液氯及氯气,一旦发生泄漏将造成人员中毒,危及到作业人员的身体健康。为定量计算氯气液化装置的泄漏概率,以某氯碱厂液氯制取系统中装置为研究对象,运用挪威船级社(DNV)的设备同类失效概率数据库,利用LEAK软件,以泄漏源工况为主要随机性因素,通过辨识研究装置中气体泄漏危险源、构建装置泄漏定量预测模型、修正相关系数,进而对氯气液化装置的泄漏概率进行了模拟计算,得出装置可能的泄漏位置和泄漏概率,可为化工企业安全管理提供指导。

使用Visual Leak Detector检测c/c++程序内存泄漏

针对内存泄漏检测问题,本文通过示例说明使用软件Visual Leak Detector来检测泄漏点的方法。通过实验说明该方法在检测一般的c/c++程序内存泄漏时,可以提高检测效率。

Outcome of stenting in biliary and pancreatic benign and malignant diseases:A comprehensive review

Endoscopic stenting has become a widely method for the management of various malignant and benign pancreatico-biliary disorders. Biliary and pancreatic stents are devices made of plastic or metal used primarily to establish patency of an obstructed bile or pancreatic duct and may also be used to treat biliary or pancreatic leaks,pancreatic fluid collections and to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis. In this review,relevant literature search and expert opinions have been used to evaluate the outcome of stenting in biliary and pancreatic benign and malignant diseases.