Functional assessment and influencing factors after staged functional training in patients with ankle fractures

BACKGROUND The recovery of limb function after ankle fracture surgery is a gradual process.The main purpose of implementing early functional exercise,joint mobility,muscle contraction function,passive ankle flexion and extension exercises,or physical factor therapy techniques is to achieve the rapid recovery of normal physiological limb function.However,currently the most effective rehabilitation training method is staged limb functional exercise,which promotes rapid recovery of limb function while preventing adverse consequences caused by overwork or insufficient training.Staged limb functional exercise divides the rehabilitation process into multiple stages,each of which has specific training objectives and contents.This method helps patients gradually restore limb function.Nevertheless,some patients still exhibit poor limb function after standardized exercise.Therefore,a functional evaluation should be performed to analyze the impact of staged functional training after ankle fracture surgery.AIM To perform a functional evaluation and determine the influencing factors of staged functional training in patients with ankle fracture.METHODS A retrospective study enrolled 150 patients who underwent surgical treatment for ankle fracture from May 2020 to May 2022 at our hospital.Univariate and multivariate linear regression analyses were performed on general data,functional exercise compliance scale for orthopedic patients,Social Support Rating Scale(SSRS),American Orthopedic Foot and Ankle Score(AOFAS)Ankle-Hindfoot Score,and pain factors[serum bradykinin(BK),prostaglandin E2(PGE2),5-hydroxytryptamine(5-HT)].RESULTS Based on the AOFAS Ankle-Hindfoot Scale,the cases were divided into the excellent function(n=111)and ordinary function(n=39)groups.Univariate analysis revealed that monthly family income,education level,diabetes mellitus,functional exercise compliance scale of orthopedic patients score,SSRS,BK,PGE2,and 5-HT significantly influenced limb function after ankle fracture(P<0.05);Multiple linear regression analysis showed that the functional exercise compliance scale score,SSRS,BK,PGE2,and 5-HT were independent risk factors affecting functional performance after staged functional exercise(P<0.05).CONCLUSION Exercise compliance,SSRS,and pain level are the independent risk factors affecting functional performance after staged functional training following ankle surgery.Clinical nursing care after ankle surgery should include analgesic and health education measures to ensure optimal recovery of limb function.

Application Effect of Staged Health Education in the Nursing Care of Patients with Upper Gastrointestinal Bleeding

Objective:To investigate the application effect of staged health education in the care of patients with upper gastrointestinal bleeding.Methods:This study takes health education in the care of patients with upper gastrointestinal bleeding as the main direction.160 patients with upper gastrointestinal bleeding who received treatment in our hospital were selected as samples,and the grouping software was used to divide them into the reference group and the study group,with 80 patients each.The reference group and the study group used routine health education and staged health education respectively.Relevant research data were recorded during the nursing process,analyzed,and used as research indicators.Results:The compliance behavior of the study group was higher than that of the reference group after the staged nursing care,and at the same time,the nursing care satisfaction of the study group was higher than that of the reference group(P<0.05).Conclusion:The use of staged health education for the care of patients with upper gastrointestinal bleeding not only enhances the degree of patient awareness and compliance but also improves nursing satisfaction,which is worthy of promotion and application.

CD4^(+)CD25^(+) regulatory T cells decreased future liver remnant after associating liver partition and portal vein ligation for staged hepatectomy

BACKGROUND Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS)is an innovative surgical approach for the treatment of massive hepatocellular carcinoma(HCC),the key to successful planned stage 2 ALPPS is future liver remnant(FLR)volume growth,but the exact mechanism has not been elucidated.The correlation between regulatory T cells(Tregs)and postoperative FLR regeneration has not been reported.AIM To investigate the effect of CD4^(+)CD25^(+)Tregs on FLR regeneration after ALPPS.METHODS Clinical data and specimens were collected from 37 patients who developed massive HCC treated with ALPPS.Flow cytometry was performed to detect changes in the proportion of CD4^(+)CD25^(+)Tregs to CD4^(+)T cells in peripheral blood before and after ALPPS.To analyze the relationship between peripheral blood CD4^(+)CD25^(+)Treg proportion and clinicopathological information and liver volume.RESULTS The postoperative CD4^(+)CD25^(+)Treg proportion in stage 1 ALPPS was negatively correlated with the amount of proliferation volume,proliferation rate,and kinetic growth rate(KGR)of the FLR after stage 1 ALPPS.Patients with low Treg proportion had significantly higher KGR than those with high Treg proportion(P=0.006);patients with high Treg proportion had more severe postoperative pathological liver fibrosis than those with low Treg proportion(P=0.043).The area under the receiver operating characteristic curve between the percentage of Tregs and proliferation volume,proliferation rate,and KGR were all greater than 0.70.CONCLUSION CD4^(+)CD25^(+)Tregs in the peripheral blood of patients with massive HCC at stage 1 ALPPS were negatively correlated with indicators of FLR regeneration after stage 1 ALPPS and may influence the degree of fibrosis in patients’livers.Treg percentage was highly accurate in predicting the FLR regeneration after stage 1 ALPPS.

Meta-analysis of efficacy and safety of concurrent or staged bilateral total knee arthroplasty

Objective: To study the safety and efficacy of concurrent bilateral total knee arthroplasty orstaged bilateral total knee replacement using meta-analysis. Methods: The databases of ChinaWanfang, CNKI, PubMed, Cochrane Library, and Web of Science were searched conducted formeta-analysis of the extracted data using Review Manager 5.3 software. Results: ①A total of 18retrospective cohort studies were included, 72 831 patients in the same period group and 103595 patients in the staging group. ②The results of meta showed that in the staging group, theincidence of postoperative cardiac complications[OR= 1.21, 95%CI=(1.10~1.34), P<0.000 1] ,neurological complications[OR=1.67, 95%CI=(1.29~2.16), P<0.000 1], deep vein thrombosis[OR=1.38, 95%CI(1.27~1.50), P<0.000 01], mortality[OR=2.18, 95%CI=(1.67~2.84),P<0.000 01] and perioperative blood loss [OR=246.75, 95%CI=(233.30~260.20)] were lessthan those in the same period group (P<0.000 01);The postoperative deep infection rate in thesame period group [OR=0.61, 95%CI=(0.52~0.71), P<0.000 01] was lower than that in thestaging group;The postoperative superficial infection rate [OR=0.96, 95%CI=(0.66~1.40)],revision rate of joint replacement [OR= 1.04, 95%CI=( 0.96~1.12)], HSS score [OR=0.10,95%CI=(-0.61~0.80), P=0.79] and knee joint activity score [OR=-0.23, 95%CI=(-1.25~0.78)]were not statistically significant between the two groups(P>0.05).Conclusion: Stagingbilateral total knee replacement can more effectively reduce the incidence of perioperativecomplications and reduce the amount of blood transfusion, while concurrent bilateral total kneereplacement can reduce the rate of deep infection. To further compare the efficacy and safety ofconcurrent or staged bilateral total knee arthroplasty, further studies must be conducted in theform of a randomized clinical trial to evaluate the results mentioned in this meta-analysis.

Outcomes of staged hepatectomies for liver malignancy

Liver malignancies are the fifth most common cause of death worldwide.Surgical intervention with curative intent is the treatment of choice for liver tumors as it provides long-term survival.However,only 20%of patients with metastatic liver lesions can be managed by curative liver resection.In most of the cases,hepatectomy is not feasible because of insufficient future liver remnant(FLR).Two-stage hepatectomy is advocated to achieve liver resection in a patient who is considered to not be a candidate for resection.Procedures of staged hepatectomy include conventional two-stage hepatectomy,portal vein embolization,and associating liver partition and portal vein ligation for a staged hepatectomy.Technical success is high for each of these procedures but variable between them.All the procedures have been reported as being effective in achieving a satisfactory FLR and completing the second-stage resection.Moreover,the overall survival and disease-free survival rates have improved significantly for patients who were otherwise considered nonresectable;yet,an increase in the morbidity and mortality rates has been observed.We suggest that this type of procedure should be carried out in high-flow centers and through a multidisciplinary approach.An experienced surgeon is key to the success of those interventions.

Associating liver partition and portal vein ligation for staged hepatectomy： the current role and development

BACKGROUND： Associating liver partition and portal vein ligation for staged hepatectomy （ALPPS） has recently been developed to induce rapid liver hypertrophy and reduce posthepatectomy liver failure in patients with insufficient future liver remnant （FLR）. ALPPS is still considered to be in an early developmental phase because surgical indications and techniques have not been standardized. This article aimed to review the current role and future developments of ALPPS. DATA SOURCES： Studies were identified by searching MED- LINE and PubMed for articles from January 2007 to October 2016 using the keywords ＂associating liver partition and portal vein ligation for staged hepatectomy＂ and ＂ALPPS＂ Addi- tional papers were identified by a manual search of references from key articles. RESULTS： ALPPS induces more hypertrophy of the FLR in less time than portal vein embolization or portal vein ligation. The benefits of ALPPS include rapid hypertrophy 47%-110% of the liver over a median of 6-16.4 days, and 95%-100% com- pletion rate of the second stage of ALPPS. The main criticisms of ALPPS are centered on its high morbidity and mortality rates. Morbidity rates after ALPPS have been reported to be 15.3%-100%, with ≥ the Clavien-Dindo grade III morbidity of 13.6%-44%. Mortality rates have been reported to be 0%-29%. The important questions to ask even if oncologic long-term results are acceptable are： whether the gain in quality and quantity of life can be off balance by the substantial risks of morbidity and mortality, and whether stimulation of rapid liver hypertrophy also accelerates rapid tumor progression and spread. Up till now, the documentations of the ALPPS procedure come mainly from case series, and most of these series include heterogeneous groups of malignancies. The numbers are also too small to separately evaluate survival for different tumor etiologies. CONCLUSIONS： Currently, knowledge on ALPPS is limited, and prospective randomized studies are lacking. From the reported preliminary results, safety of the ALPPS procedure remains questionable. ALPPS should only be used in experienced, high-volume hepatobiliary centers.

Associating liver partition and portal vein ligation for staged hepatectomy: From technical evolution to oncological benefit

Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS) is a novel approach in liver surgery that allows for extensive resection of liver parenchyma by inducing a rapid hypertrophy of the future remnant liver. However,recent reports indicate that not all patients eligible for ALPPS will benefit from this procedure. Therefore,careful patient selection will be necessary to fully exploit possible benefits of ALPPS. Here,we provide a comprehensive overview of the technical evolution of ALPPS with a special emphasis on safety and oncologic efficacy. Furthermore,we review the contemporary literature regarding indication and benefits,but also limitations of ALPPS.

Role of associating liver partition and portal vein ligation for staged hepatectomy in colorectal liver metastases:A review

Colorectal cancer is the third most common cancer in the Western world. Approximately half of patients will develop liver metastases, which is the most common cause of death. The only potentially curative treatment is surgical resection. However, many patients retain a to small future liver remnant(FLR) to allow for resection directly. There are therefore strategies todecrease the tumor with neoadjuvant chemotherapy and to increase the FLR. An accepted strategy to increase the FLR is portal vein occlusion(PVO). A concern with this strategy is that a large proportion of patients will never be operated because of progression during the interval between PVO and resection. ALPPS(associating liver partition and portal vein ligation for staged hepatectomy) is a new procedure with a high resection rate. A concern with this approach is the rather high frequency of complications and high mortality, compared to PVO. In this review, it is shown that with ALPPS the resection rate was 97.1% for CRLM and the mortality rate for all diagnoses was 9.6%. The mortality rate was likely lower for patients with CRLM, but some data were lacking in the reports. Due to the novelty of ALPPS, the indications and technique are not yet established but there are arguments for ALPPS in the context of CRLM and a small FLR.

Rescue associating liver partition and portal vein ligation for staged hepatectomy after portal embolization: Our experience and literature review

AIM To report a single-center experience in rescue associating liver partition and portal vein ligation for staged hepatectomy(ALPPS), after failure of previous portal embolization. We also performed a literature review.METHODS Between January 2014 and December 2015, every patient who underwent a rescue ALPPS procedure in Toulouse Rangueil University Hospital, France, was included. Every patient included had a project of major hepatectomy and a previous portal vein embolization(PVE) with insufficient future liver remnant to body weight ratio after the procedure. The ALPPS procedure was performed in two steps(ALPPS-1 and ALPPS-2), separated by an interval phase. ALPPS-2 was done within 7 to 9 d after ALPPS-1. To estimate the FLR, a computed tomography scan examination was performed 3 to 6 wk after the PVE procedure and 6 to 8 d after ALPPS-1. A transcystic stent was placed during ALPPS-1 and remained opened duringthe interval phase, in order to avoid biliary complications. Postoperative liver failure was defined using the 50-50 criteria. Postoperative complications were assessed according to the Dindo-Clavien Classification.RESULTS From January 2014 to December 2015, 7 patients underwent a rescue ALPPS procedure. Median FLR before PVE, ALPPS-1 and ALPPS-2 were respectively 263 cc(221-380), 450 cc(372-506), and 660 cc(575-776). Median FLR/BWR before PVE, ALPPS-1 and ALPPS-2 were respectively 0.4%(0.3-0.5), 0.6%(0.5-0.8), and 1%(0.8-1.2). Median volume growth of FLR was 69%(18-92) after PVE, and 45%(36-82) after ALPPS-1. The combination of PVE and ALPPS induced a growth of median initial FLR of +408 cc(254-513), leading to an increase of +149%(68-199). After ALPPS-2, 4 patients had stage Ⅰ-Ⅱ complications. Three patients had more severe complications(one stage Ⅲ, one stage Ⅳ and one death due to bowel perforation). Two patients suffered from postoperative liver failure according to the 50/50 criteria. None of our patients developed any biliary complication during the ALPPS procedure.CONCLUSION Rescue ALPPS may be an alternative after unsuccessful PVE and could allow previously unresectable patients to reach surgery. Biliary drainage seems to reduce biliary complications.

Current status of associating liver partition with portal vein ligation for staged hepatectomy: Comparison with two-stage hepatectomy and strategies for better outcomes

Since its introduction in 2012,associating liver partition with portal vein ligation for staged hepatectomy(ALPPS)has significantly expanded the pool of candidates for liver resection.It offers patients with insufficient liver function a chance of a cure.ALPPS is most controversial when its high morbidity and mortality is concerned.Operative mortality is usually a result of posthepatectomy liver failure and can be minimized with careful patient selection.Elderly patients have limited reserve for tolerating the demanding operation.Patients with colorectal liver metastasis have normal liver and are ideal candidates.ALPPS for cholangiocarcinoma is technically challenging and associated with fair outcomes.Patients with hepatocellular carcinoma have chronic liver disease and limited parenchymal hypertrophy.However,in selected patients with limited hepatic fibrosis satisfactory outcomes have been produced.During the inter-stage period,serum bilirubin and creatinine level and presence of surgical complication predict mortality after stage II.Kinetic growth rate and hepatobiliary scintigraphy also guide the decision whether to postpone or omit stage II surgery.The outcomes of ALPPS have been improved by a combination of technical modifications.In patients with challenging anatomy,partial ALPPS potentially reduces morbidity,but remnant hypertrophy may compare unfavorably to a complete split.When compared to conventional two-stage hepatectomy with portal vein embolization or portal vein ligation,ALPPS offers a higher resection rate for colorectal liver metastasis without increased morbidity or mortality.While ALPPS has obvious theoretical oncological advantages over two-stage hepatectomy,the long-term outcomes are yet to be determined.

maturity of associating liver partition and portal vein ligation for staged hepatectomy-derived liver regeneration in a rat model

AIM To establish a rat model for evaluating the maturity of liver regeneration derived from associating liver partition and portal vein ligation for staged hepatectomy(ALPPS).METHODS In the present study, ALPPS, partial hepatecotmy(PHx), and sham rat models were established initially, which were validated by significant increase of proliferative markers including Ki-67, proliferating cell nuclear antigen, and cyclin D1. In the setting of accelerated proliferation in volume at the second and fifth day after ALPPS, the characteristics of newborn hepatocytes, as well as specific markers of progenitor hepatic cell, were identified. Afterwards, the detection of liver function followed by cluster analysis of functional gene expression were performed to evaluate the maturity.RESULTS Compared with PHx and sham groups, the proliferation of f LR was significantly higher in ALPPS group(P = 0.023 and 0.001 at second day, P = 0.034 and P < 0.001 at fifth day after stage I). Meanwhile, the increased expression of proliferative markers including Ki-67, proliferating cell nuclear antigen, and cyclin D1 verified the accelerated liver regeneration derived from ALPPS procedure. However, ALPPS-induced Sox9 positive hepatocytes significantly increased beyond the portal triad, which indicated the progenitor hepatic cell was potentially involved. And the characteristics of ALPPSinduced hepatocytes indicated the lower expression of hepatocyte nuclear factor 4 and anti-tryptase in early proliferative stage. Both suggested the immaturity of ALPPS-derived liver regeneration. Additionally, the detection of liver function and functional genes expression confirmed the immaturity of renascent hepatocytes derived in early stage of ALPPS-derived liver regeneration.CONCLUSION Our study revealed the immaturity of ALPPS-derived proliferation in early regenerative response, which indicated that the volumetric assessment overestimated the functional proliferation. This could be convincing evidence that the stage Ⅱ of ALPPS should be performed prudently in patients with marginally adequate f LR, as the ALPPS-derived proliferation in volume lags behind the functional regeneration.

Evolution of associating liver partition and portal vein ligation for staged hepatectomy: Simpler, safer and equally effective methods

Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS) has been recently demonstrated as a method to induce rapid and extensive hypertrophy within a short time and has been employed for a variety of primary and metastatic liver tumors. However, controversies remain due to its high morbidity and mortality. To enable safer surgery, liver surgeons have searched for better technical modifications, such as partial ALPPS, mini-ALPPS, minimally invasive ALPPS, and Terminal branches portal vein Embolization Liver Partition for Planned hepatectomy(TELPP). It seems that TELPP is very promising, because it has the main advantage of ALPPS-the rapid increase of future liver remnant volume, but the morbidity and mortality are much lower because only one surgical operation is required.

Complete or partial split in associating liver partition and portal vein ligation for staged hepatectomy: A systematic review and meta-analysis

BACKGROUND Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS)has been adopted by liver surgeons in recent years.However,high morbidity and mortality rates have limited the promotion of this technique.Some recent studies have suggested that ALPPS with a partial split can effectively induce the growth of future liver remnant(FLR)similar to a complete split with better postoperative safety profiles.However,some others have suggested that ALPPS can induce more rapid and adequate FLR growth,but with the same postoperative morbidity and mortality rates as in partial split of the liver parenchyma in ALPPS(p-ALPPS).AIM To perform a systematic review and meta-analysis on ALPPS and p-ALPPS.METHODS A systematic literature search of PubMed,Embase,the Cochrane Library,and ClinicalTrials.gov was performed for articles published until June 2019.Studies comparing the outcomes of p-ALPPS and ALPPS for a small FLR in consecutive patients were included.Our main endpoints were the morbidity,mortality,and FLR hypertrophy rates.We performed a subgroup analysis to evaluate patients with and without liver cirrhosis.We assessed pooled data using a random-effects model.RESULTS Four studies met the inclusion criteria.Four studies reported data on morbidity and mortality,and two studies reported the FLR hypertrophy rate and one study involved patients with cirrhosis.In the non-cirrhotic group,p-ALPPS-treated patients had significantly lower morbidity and mortality rates than ALPPStreated patients[odds ratio(OR)=0.2;95%confidence interval(CI):0.07–0.57;P=0.003 and OR=0.16;95%CI:0.03-0.9;P=0.04].No significant difference in the FLR hypertrophy rate was observed between the two groups(P>0.05).The total effects indicated no difference in the FLR hypertrophy rate or perioperative morbidity and mortality rates between the ALPPS and p-ALPPS groups.In contrast,ALPPS seemed to have a better outcome in the cirrhotic group.CONCLUSION The findings of our study suggest that p-ALPPS is safer than ALPPS in patients without cirrhosis and exhibits the same rate of FLR hypertrophy.

Long-term outcomes of staged recanalization for concurrent chronic total occlusion in patients with ST-segment elevation myocardial infarction after primary percutaneous coronary intervention

Background In patients with acute ST-segment elevation myocardial infarction(STEMI)who undergo primary percutaneous coronary intervention(PCI),approximately 10%are concomitant with a chronic total occlusion(CTO)in a non-culprit vessel.However,the impact of staged CTO recanalization on prognosis in this cohort remains disputable.This study aimed to compare the long-term outcomes of staged CTO recanalization versus medical therapy in patients with STEMI after primary PCI.Methods Between January 2005 and December 2016,a total of 287 patients were treated with staged CTO-PCI(n=91)or medical therapy(n=196)after primary PCI in our center.The primary endpoint was major adverse cardiovascular and cerebrovascular event(MACCE),defined as a composite of all-cause death,nonfatal myocardial infarction(MI),stroke or unplanned revascularization.After propensity-score matching,77 pairs of well-balanced patients were identified.Results The mean follow-up period was 6.06 years.Overall,the incidence of the primary endpoint of MACCE was significantly lower in staged CTO-PCI group than that in medical therapy group in both overall population(22.0%vs.46.9%;hazard ratio(HR)=0.48,95%CI:0.29-0.77)and propensity-matched cohorts(22.1%vs.42.9%;HR:0.48,95%CI:0.27-0.86).In addition,staged CTO-PCI was also associated with reduced risk of the composite of cardiac death,nonfatal MI or stroke compared with medical therapy in both overall population(9.9%vs.26.5%;hazard ratio(HR)=0.39,95%CI:0.19-0.79)and propensity-matched cohorts(9.1%vs.22.1%;HR:0.40,95%CI:0.16-0.96).After correction of the possible confounders,staged CTO-PCI was independently associated with reduced risks of MACCE(adjusted HR:0.46,95%CI:0.28-0.75),the composite of cardiac death,nonfatal MI or stroke(adjusted HR:0.45,95%CI:0.22-0.94)and all-cause mortality(adjusted HR:0.32,95%CI:0.13-0.83).Moreover,the results of sensitivity analysis were almost concordant with the overall analysis.Conclusions In patients with STEMI and a concurrent CTO who undergo primary PCI,successful staged recanalization of CTO in the non-culprit vessels is associated with better clinical outcomes during long-term follow-up.

Performance of supersonic model combustors with staged injections of supercritical aviation kerosene

Supersonic model combustors using two-stage injections of supercritical kerosene were experimentally investigated in both Mach 2.5 and 3.0 model combustors with stagnation temperatures of approximately 1,750 K. Supercritical kerosene of approximately 760 K was prepared and injected in the overall equivalence ratio range of 0.5-1.46. Two pairs of integrated injector/flameholder cavity modules in tandem were used to facilitate fuel-air mixing and stable combustion. For single-stage fuel injection at an upstream location, it was found that the boundary layer separation could propagate into the isolator with increasing fuel equivalence ratio due to excessive local heat release, which in turns changed the entry airflow conditions. Moving the fuel injection to a further downstream location could alleviate the problem, while it would result in a decrease in combustion efficiency due to shorter fuel residence time. With two-stage fuel injections the overall combustor performance was shown to be improved and kerosene injections at fuel rich conditions could be reached without the upstream propagation of the boundary layer separation into the isolator. Furthermore, effects of the entry Mach number and pilot hydrogen on combustion performance were also studied.

A quantitative model for danger degree evaluation of staged operation of earth dam reservoir in flood season and its application

Based on the natural disaster risk evaluation mode, a quantitative danger degree evaluation model was developed to evaluate the danger degree of earth dam reservoir staged operation in the flood season. A formula for the overtopping risk rate of the earth dam reservoir staged operation was established, with consideration of the joint effect of flood and wind waves in the flood sub-seasons with the Monte Carlo method, and the integrated overtopping risk rate for the whole flood season was obtained via the total probability approach. A composite normalized function was used to transform the dam overtopping risk rate into the danger degree, on a scale of 0-1. Danger degree gradating criteria were divided by four significant characteristic values of the dam overtopping rate, and corresponding guidelines for danger evaluation are explained in detail in this paper. Examples indicated that the dam overtopping danger degree of the Chengbihe Reservoir in China was 0.33-0.57, within the range of moderate danger level, and the flood-limiting water level （FLWL） can be adjusted to 185.00 m for the early and main flood seasons, and 185.00-187.50 m for the late flood season. The proposed quantitative model offers a theoretical basis for determination of the value of the danger degree of an earth dam reservoir under normal operation as well as the optimal scheduling scheme for the reservoir in each stage of the flood season.

Dynamic properties and liquefaction behaviour of cohesive soil in northeast India under staged cyclic loading

Estimation of strain-dependent dynamic soil properties, e.g. the shear modulus and damping ratio, along with the liquefaction potential parameters, is extremely important for the assessment and analysis of almost all geotechnical problems involving dynamic loading. This paper presents the dynamic properties and liquefaction behaviour of cohesive soil subjected to staged cyclic loading, which may be caused by main shocks of earthquakes preceded or followed by minor foreshocks or aftershocks, respectively. Cyclic triaxial tests were conducted on the specimens prepared at different dry densities （1.5 g/cm3 and 1.75 g/cm3） and different water contents ranging from 8% to 25%. The results indicated that the shear modulus reduction （G/Gmax） and damping ratio of the specimen remain unaffected due to the changes in the initial dry density and water content. Damping ratio is significantly affected by confining pressure, whereas G/Gmax is affected marginally. It was seen that the liquefaction criterion of cohesive soils based on single-amplitude shear strain （3.75% or the strain at which excess pore water pressure ratio becomes equal to 1, whichever is lower） depends on the initial state of soils and applied stresses. The dynamic model of the regional soil, obtained as an outcome of the cyclic triaxial tests, can be successfully used for ground response analysis of the region.

Micro-annulus generation under downhole conditions: Insights from three-dimensional staged finite element analysis of cement hardening and wellbore operations

A micro-annulus(MA)is defined as a high permeability zone or gap initiating/occurring at the casingcement and cement-formation interfaces during the wellbore life span.An MA can significantly compromise wellbore integrity by establishing enhanced fluid flow pathways.This study uses a staged finite element approach to simulate wellbore integrity during various loading steps of wellbore operations under downhole conditions.Particular emphasis is placed on the processes of cement poro-elastic property evolution,volume variation,and pore pressure variation as part of the cement hardening step.The resulting state of stress during the life cycle of a typical injection well(i.e.hardening,completion,and injection)is analyzed to assess the onset and evolution of micro-annuli at various interfaces of the composite wellbore system under downhole conditions.The results show that cement shear failure is observed at the casing-cement interface during pressure testing(excessive wellbore pressure);and tensile debonding failure initiates at the cement-formation interface due to cement shrinkage during hardening and injection-related cooling(thermal cycling).Sensitivity analyses considering several parameters show that:(1)the degree of poro-elastic bulk shrinkage has significant implications for both shear and tensile failure initiation e the less the cement shrinks,the less likely the failure initiation is;(2)cement integrity increases with increasing depth;(3)cement pore pressure evolution has significant implications for tensile failure e if cement pore pressure decreases more,higher temperature differences can be sustained before an MA occurs;and(4)cement temperature fluctuations during hardening promote initiation of debonding failure.In summary,the results presented indicate that establishing downhole conditions to quantitatively analyze MA generation is necessary.The results are different compared to laboratory studies without considering/simulating downhole conditions.The knowledge from this study can raise the awareness of predicting and evaluating MA under downhole conditions and can be used to supplement and improve future laboratory experiments.

Associating liver partition and portal vein ligation for staged hepatectomy in the treatment of colorectal cancer liver metastases

Colorectal cancer(CRC)is a common malignancy of the digestive system.Colorectal liver cancer metastasis(CRLM)occurs in approximately 50%of the patients and is the main cause of CRC mortality.Surgical resection is currently the most effective treatment for CRLM.However,given that the remnant liver volume after resection should be adequate,only a few patients are suitable for radical resection.Since Dr.Hans Schlitt first performed the associating liver partition and portal vein ligation for staged hepatectomy(ALPPS)for CRLM in 2012,ALPPS has received considerable attention and has continually evolved in recent years.This review explains the technical origin of the ALPPS procedure for CRLM and evaluates its efficacy,pointing to its favorable postoperative outcomes.We also discuss the patient screening strategies and optimization of ALPPS to ensure long-term survival of patients with CRLM in whom surgery cannot be performed.Finally,further directions in both basic and clinical research regarding ALPPS have been proposed.Although ALPPS surgery is a difficult and high-risk technique,it is still worth exploration by experienced surgeons.

Abdominal cross-sectional imaging of the associating liver partition and portal vein ligation for staged hepatectomy procedure

Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS) is a recently introduced technique aimed to perform two-stage hepatectomy in patients with a variety of primary or secondary neoplastic lesions. ALPSS is based on a preliminary liver resection associated with ligation of the portal branch directed to the diseased hemiliver(DH), followed by hepatectomy after an interval of time in which the future liver remnant(FLR) hypertrophied adequately(partly because of preserved arterialization of the DH). Multidetector computed tomography(MDCT) and magnetic resonance imaging(MRI) play a pivotal role in patients' selection and FLR assessment before and after the procedure, as well as in monitoring early and late complications, as we aim to review in this paper. Moreover, we illustrate main abdominal MDCT and MRI findings related to ALPPS.