Description of a novel robotic early post-prostatectomy anastomotic repair technique and institutional outcomes

Objective:A vesicourethral anastomotic leak(VUAL)is a known complication following robotic-assisted radical prostatectomy.The natural history of a VUAL has been well described and is frequently managed with prolonged catheterization.With increasing emphasis on patient reported outcomes,catheter duration and VUAL are associated with significant short-term quality of life impairment.We aimed to present a case series of our robotic early post-prostatectomy anastomotic repair technique,defined as revision within 6 weeks from index surgery.Methods:A single institution prospective database identified eleven patients with a VUAL from July 2016 to October 2022 who underwent robotic early post-prostatectomy anastomotic repair by a single surgeon.Patients were diagnosed with a VUAL on pre-operative CT urogram or CT/fluoroscopic cystogram.The primary outcome was resolution of the anastomotic leak,defined as no contrast extravasation on post-operative cystography.Secondary outcomes included post-repair catheter duration and continence on the last follow-up defined as pad(s)per day.Results:The mean time to intervention after robotic-assisted radical prostatectomy was 21 days.Eight of the eleven(72.7%)patients had no evidence of extravasation on postrepair cystogram.The range from intervention to first cystogram was 7e20 days.The median catheter duration for those with successful intervention was 10 days.The median catheter duration for those with the leak on initial post-operative cystogram was 20 days.At a mean follow-up time of 25 months,eight(72.7%)patients reported using no pads per day,and three(27.3%)patients reported one pad per day.Conclusion:Management of a VUAL has traditionally relied on prolonged catheter drainage and the tincture of time.As the role of robotic reconstruction has been shown to be a viable modality for management of bladder neck contracture,it is important to reconsider prior dogmas of urologic care.Our case series suggests that an early repair is safe and has a high success rate.Early robotic intervention gives providers an additional tool in aiding patient recovery.

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.

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.

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.

Effect of rapid rehabilitation nursing on improving clinical outcomes in postoperative patients with colorectal cancer

BACKGROUND Surgical resection is the cornerstone treatment for colorectal cancer.Rapid rehabilitation care predicated on evidence-based medical theory aims to improve postoperative nursing care,subsequently reducing the physical and mental traumatic stress response and helping patients who undergo surgery recover rapidly.AIM To assess the effect of rapid rehabilitation care on clinical outcomes,including overall postoperative complications,anastomotic leaks,wound infections,and intestinal obstruction in patients with colorectal cancer.METHODS We searched the PubMed,Web of Science,Embase,Elsevier Science Direct,and Springer Link databases from January 1,2010,to January 1,2024,to screen eligible studies on rapid rehabilitation care among patients who underwent colorectal cancer surgery.Patients were screened based on the inclusion and exclusion criteria.RevMan 5.4 software was used for statistical analysis of the data.RESULTS Twelve studies were enrolled,which included 2420 patients.The results showed that rapid rehabilitation care decreased the incidence of overall postoperative complications(OR:0.44,95%CI:0.26–0.74,P=0.002),anastomotic leaks(OR:0.68,95%CI:0.41–1.12,P=0.13),wound infections(OR:0.45,95%CI:0.29–0.72,P=0.0007),and intestinal obstruction(OR:0.54,95%CI:0.34–0.86,P=0.01)compared to conventional care.Further trials and studies are needed to confirm these results.CONCLUSION Rapid rehabilitation care decreased the occurrence of postoperative complications,anastomotic leaks,wound infections,and intestinal obstruction compared to conventional care in patients who underwent colorectal surgery.Therefore,promoting the application of rapid rehabilitation care in clinical practice cannot be overemphasized.

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.

Preservation of superior rectal artery in laparoscopic colectomy:The best choice for slow transit constipation?

Laparoscopic colectomy with ileorectal anastomosis may be beneficial for patients with slow transit constipation who do not respond to conservative treatment,particularly if the superior rectal artery(SRA)is preserved.Several important concerns have been addressed in this commentary.It is important to first go over the definition of surgical procedure as it is used in this text.Second,the current study lacked a control group that had SRA preservation.Thirdly,it would be best to use a prospective,randomized controlled study.Lastly,a description of the mesenteric defect’s state following a laparoscopic colectomy is necessary.

How to preserve the native or reconstructed esophagus after perforations or postoperative leaks: A multidisciplinary 15-year experience

BACKGROUND Esophageal perforation or postoperative leak after esophageal surgery remain a life-threatening condition.The optimal management strategy is still unclear.AIM To determine clinical outcomes and complications of our 15-year experience in the multidisciplinary management of esophageal perforations and anastomotic leaks.METHODS A retrospective single-center observational study was performed on 60 patients admitted at our department for esophageal perforations or treated for an anastomotic leak developed after esophageal surgery from January 2008 to December 2023.Clinical outcomes were analyzed,and complications were evaluated to investigate the efficacy and safety of our multidisciplinary management based on the preservation of the native or reconstructed esophagus,when feasible.RESULTS Among the whole series of 60 patients,an urgent surgery was required in 8 cases due to a septic state.Fifty-six patients were managed by endoscopic or hybrid treatments,obtaining the resolution of the esophageal leak/perforation without removal of the native or reconstructed esophagus.The mean time to resolution was 54.95±52.64 days,with a median of 35.5 days.No severe complications were recorded.Ten patients out of 56(17.9%)developed pneumonia that was treated by specific antibiotic therapy,and in 6 cases(10.7%)an atrial fibrillation was recorded.Seven patients(12.5%)developed a stricture within 12 months,requiring one or two endoscopic pneumatic dilations to solve the problem.Mortality was 1.7%.CONCLUSION A proper multidisciplinary approach with the choice of the most appropriate treatment can be the key for success in managing esophageal leaks or perforations and preserving the esophagus.

Surgeon Perspectives on Anastomotic Leaks and FluidAI’s StreamTM Platform: Integrating Qualitative Insights for Technological Innovation

Purpose: This article investigates the critical importance of integrating surgeons’ direct input into the development of innovative technologies that address gaps in surgical care, including those aimed at reducing anastomotic leaks (AL), a major complication in gastrointestinal surgery. While traditional quantitative research methods are prevalent, they often overlook the invaluable insights of the surgeons who manage these complications firsthand. Subjects and Methods: This study employs a qualitative approach, utilizing semi-structured interviews with 40 surgeons from various specialties, including general, bariatric, colorectal, trauma, hepato-biliary, and thoracic surgery. The interviews were designed to probe the needs of surgeons, challenges currently faced, and gaps in clinical practice, research, and technology for detection and/or management of AL. The data were analyzed using thematic analysis, which revealed significant gaps in current technologies for early detection and prevention of leaks. Results: Surgeons expressed strong interest in FluidAI’s Stream™ Platform, a non-invasive medical device designed to monitor postoperative drainage fluid in real-time, providing continuous data on AL risk. The ability of this platform to offer early prediction through pH and electrical conductivity analysis was particularly appealing to participants, who emphasized the importance of timely interventions in improving patient outcomes. The study’s findings highlight not only the clinical challenges but also the emotional toll that AL takes on surgeons, underlining the need for innovations that are both data-driven and humanistic. Conclusion: By centering surgeons’ perspectives, this research advocates for a human-centered approach to technological advancement, ensuring that new tools are both clinically effective and aligned with the real-world needs of surgical practitioners.

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.

Endoscopic luminal stenting:Current applications and future perspectives

Endoscopic luminal stenting(ELS)represents a minimally invasive option for the management of malignant obstruction along the gastrointestinal tract.Previous studies have shown that ELS can provide rapid relief of symptoms related to esophageal,gastric,small intestinal,colorectal,biliary,and pancreatic neoplastic strictures without compromising cancer patients’overall safety.As a result,in both palliative and neoadjuvant settings,ELS has largely surpassed radiotherapy and surgery as a first-line treatment modality.Following the abovementioned success,the indications for ELS have gradually expanded.To date,ELS is widely used in clinical practice by well-trained endoscopists in managing a wide variety of diseases and complications,such as relieving non-neoplastic obstructions,sealing iatrogenic and non-iatrogenic perforations,closing fistulae and treating post-sphincterotomy bleeding.The abovementioned development would not have been achieved without corresponding advances and innovations in stent technology.However,the technological landscape changes rapidly,making clinicians’adaptation to new technologies a real challenge.In our mini-review article,by systematically reviewing the relevant literature,we discuss current developments in ELS with regard to stent design,accessories,techniques,and applications,expanding the research basis that was set by previous studies and highlighting areas that need to be further investigated.

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.

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%.

Clinical management of dural defects:A review

Dural defects are common in spinal and cranial neurosurgery.A series of complications,such as cerebrospinal fluid leakage,occur after rupture of the dura.Therefore,treatment strategies are necessary to reduce or avoid complications.This review comprehensively summarizes the common causes,risk factors,clinical complications,and repair methods of dural defects.The latest research progress on dural repair methods and materials is summarized,including direct sutures,grafts,biomaterials,non-biomaterial materials,and composites formed by different materials.The characteristics and efficacy of these dural substitutes are reviewed,and these materials and methods are systematically evaluated.Finally,the best methods for dural repair and the challenges and future prospects of new dural repair materials are discussed.

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.

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.