Bridging and downstaging treatments for hepatocellular carcinoma in patients on the waiting list for liver transplantation

Several therapeutic procedures have been proposed as bridging treatments for patients with hepatocellular carcinoma(HCC)awaiting liver transplantation(LT).The most used treatments include transarterial chemoembolization and radiofrequency ablation.Surgical resection has also been successfully used as a bridging procedure,and LT should be considered a rescue treatment in patients with previous HCC resection who experience tumor recurrence or post-treatment severe decompensation of liver function.The aims of bridging treatments include decreasing the waiting list dropout rate before transplantation,reducing HCC recurrence after transplantation,and improving post-transplant overall survival.To date,no data from prospective randomized studies are available;however,for HCC patients listed for LT within the Milan criteria,prolonging the waiting time over 6-12 mo is a risk factor for tumor spread.Bridging treatments are useful in containing tumor progression and decreasing dropout.Furthermore,the response to pre-LT treatments may represent a surrogate marker of tumor biological aggressiveness and could therefore be evaluated to prioritize HCC candidates for LT.Lastly,although a definitive conclusion can not be reached,the experiences reported to date suggest a positive impact of these treatments on both tumor recurrence and post-transplant patient survival.Advanced HCC may be downstaged to achieve and maintain the current conventional criteria for inclusion in the waiting list for LT.Recent studies have demonstrated that successfully downstaged patients can achieve a 5-year survival rate comparable to that of patients meeting the conventional criteria without requiring downstaging.

Reducing Paediatric Outpatient Waitlists—A Proposed Allied Health Multidisciplinary Approach

Extremely long Australian paediatric outpatient waiting lists have resulted in large numbers of children waiting to see a paediatrician. Analyses of the patient referrals suggest that a large proportion of children may benefit from allied health input, in addition to being seen by the paediatrician. This paper provides an organisational strategy that involves streamlining Allied Health clinical services in an effort to assist with bringing down a Paediatric Out-patient waitlist. The paper describes principles to guide the formation of a Paediatric Allied Health Multi-Disciplinary team that proposes assessment and brief interventions. The service would focus on supporting the paediatricians through the use of structured procedures, telephone intakes, multidisciplinary triage, shared and standardised assessments, collaborative formulations and reports, brief interventions, clinical-community linkages, and allied health student support. A variety of additional important organisational principles are proposed to facilitate patient flow from the perspective of streamlining administrative processes, having adequate administrative support, shared responsibilities, teamwork, flexibility, carrying out intake assessments, determining which referrals were appropriate for allied health, and working closely with medical staff.

餐饮等位系统需求分析与设计

随着人们生活水平的不断提高,外出就餐的人数也越来越多,尤其在节假日里,顾客在比较火爆的餐厅进行排队等台是不可避免的。这就要求餐厅经营者要切实提高管理水平,加入更多人性化等台管理因素。基于此现状本文探讨一个基于Android移动端的在线餐饮等位系统需求分析与设计。

Contemporary characteristics and outcomes of adults with familial dilated cardiomyopathy listed for heart transplantation

BACKGROUND Familial dilated cardiomyopathy(FDCM) account for 20%-30% of non-ischemic cardiomyopathies(NICM). Previous published data showed that some patients with FDCM tend to have rapidly progressive disease; however, five-year mortality was not significantly different in the familial and non-familial forms of NICM with optimal medical therapy.AIM To better define the characteristics and clinical outcomes of FDCM patients listed for heart transplantation(HT).METHODS We queried the United Network for Organ Sharing Registry to identify FDCM patients listed for HT between January 2008 and September 2015 and compared them to NICM and ischemic cardiomyopathy(ICM) patients. We included all patients ≥ 18 years old and we separated patients to three groups: FDCM, NICM and ICM. Chi-square test was used to compare between categorical variables, the t-test was used to compare between continues variables, and Cox-proportional hazards model was used to perform time-dependent survival analyses.RESULTS Of the 24809 adults listed for HT, we identified 677 patients(2.7%) with the diagnosis of FDCM. Compared to patients with NICM and ICM, FDCM patients were younger(FDCM 43.9 ± 13.5 vs NICM 50.9 ± 12.3, P < 0.001, vs ICM 58.5 ±8.1, P < 0.001), more frequently listed as status 2(FDCM 35.2% vs NICM 26.5%, P< 0.001), with significantly lower left ventricular assist device(LVAD) utilization(FDCM 18.4% vs NICM 25.1%, P < 0.001; vs ICM 25.6%, P < 0.001), but higher use of total artificial heart(FDCM 1.3% vs NICM 0.6%, P = 0.039; vs ICM 0.4%, P =0.002). Additionally, patients with FDCM were less frequently delisted for clinical deterioration or death and more likely to be transplanted compared to those with NICM [hazard ratio(HR): 0.617, 95% confidence interval(CI): 0.47-0.81; HR: 1.25,95%CI: 1.14-1.37, respectively], and ICM(HR: 0.5, 95%CI: 0.38-0.66; HR: 1.18,95%CI: 1.08-1.3, respectively). There was more frequent rejection among patients with FDCM(FDCM 11.4% vs NICM 9.8%, P = 0.28; vs ICM 8.4%, P = 0.034). One,three, and five post-transplant survival of patients with FDCM(91%, 88% and80%) was similar to those with NICM(91%, 84%, 79%, P = 0.225), but superior to those with ICM(89%, 82%, 75%, P = 0.008), respectively.CONCLUSION End-stage FDCM patients are more likely to be transplanted, more likely to have early rejection, and have similar or higher survival than patients with other cardiomyopathies.

Non-Invasive Vibration-Stress of the Cirrhotic Liver of Patients Waiting for Transplantation Induces of Circulating CD133+ Stem Lymphocytes Committed Phenotypically toward the Liver

Background: Numerous studies of tissues’ regeneration have confessed the recovery of damaged liver by hematopoietic stem cells. The cells act not only by cell replacement in the target organ but also by delivering trophic factors that support endogenous liver regeneration. A little is known of how organ-derived signals recruit such committed cells into circulation. Objective: We investigated the roles of noninvasive mechanical percutaneous stress of cirrhotic human liver in numbers fluctuation of trophic, liver-specific alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells in lymphocytes of patients waiting for liver transplantation. Methods: To promote in blood the number of the alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells, committed to liver’ tissue, we activated mechanically the cirrhotic liver of patient by transcutaneous micro vibration received from skin-contacted electro-magnetic vibraphones generated mechanical pulses with amplitude 10 μm and smoothly changing frequency from 0.03 kHz to 18 kHz and back forth during one cycle duration 1 minute. The number of the alpha-fetoprotein-positive fraction of CD133-positive hematopoietic stem cells in lymphocytes of potential recipients was controlled by flow cytometry before and during daily sonication of skin area, which corresponds to liver projection on it. The 15 minutes cyclic sonication of the liver area performed daily for three weeks. Results: The sonication increased significantly averaged number of liver-specific alpha-fetoprotein-positive CD133-positive blood lymphocytes in 2 - 3 times compared to a base lane. The second similar sonication, the same zone after three weeks break showed differences with baseline, but it was statistically insignificant. The result was specifically related to the liver as it showed the control sonication of the backbone’s projection on the skin of a separate group of patients with cirrhotic liver from the waiting list. Conclusion: The stem cells committed to the liver recruit from the bone marrow into circulation, when organ mechanically stresses and secretes specific humoral signals to provoke of lymphopoiesis on host liver repair.

A mathematical model for shortening waiting time in pancreas-kidney transplantation

AIM: To simulate a hypothetical increase of 50% in the number of pancreas-kidney (PK) transplantations using less-than-ideal donors by a mathematical model. METHODS: We projected the size of the waiting list by taking into account the incidence of new patients per year, the number of PK transplantations carried out in the year and the number of patients who died on the waiting list or were removed from the list for other reasons. These variables were treated using a model developed elsewhere. RESULTS: We found that the waiting list demand will meet the number of PK transplantation by the year 2022. CONCLUSION: In future years, it is perfectly possible to minimize the waiting list time for pancreas transplantation through expansion of the donor pool using less-than-ideal donors.

Pain and function deteriorate in patients awaiting total joint arthroplasty that has been postponed due to the COVID-19 pandemic

BACKGROUND Elective total joint arthroplasty(TJA)procedures have been postponed as part of the coronavirus disease 2019(COVID-19)response to avert healthcare system collapse.Total hip arthroplasty(THA)and total knee arthroplasty(TKA)procedures comprise the highest volume of elective procedures performed at health care facilities worldwide.AIM To determine the demand for TJA despite the pandemic and the impact of surgery postponement on physical and mental health.METHODS We conducted a prospective cross-sectional telephonic interview-based study on patients awaiting THA and TKA at an academic institution in South Africa.The questionnaire consisted of four sections.The first section recorded baseline demographic data and medical co-morbidities,the length of time spent awaiting TJA,and the patients’desire to undergo elective surgery despite the COVID-19 pandemic.Section 2 and Section 3 assessed the patients’current physical and mental health,respectively,as a consequence of deferred surgical intervention.The last section established the patients’perception of the healthcare system’s response to the COVID-19 pandemic and necessity to postpone elective surgery.Patients received counseling and education on the current state of surgery during the COVID-19 pandemic and associated risks.Thereafter,patients were once again asked about their desire to undergo TJA during the COVID-19 pandemic.RESULTS We included 185 patients(65.95%female;mean age:50.28 years)awaiting TJA for a mean of 26.42±30.1 mo.Overall,88.65%of patients wanted TJA despite the COVID-19 pandemic.Patients awaiting TJA for 1-3 years were 3.3-fold more likely to want surgery than those waiting<1 year(P<0.000).Patients with comorbidities were 8.4-fold less likely to want TJA than those with no comorbidities(P=0.013).After receiving education,the patients wanting TJA decreased to 54.05%.Patients who changed their opinion after education had less insight on the increased morbidity(P=0.046)and mortality(P=0.001)associated with COVID-19.Despite awaiting TJA for shorter period(24.7±20.38 mo),patients who continued to demand TJA had greater pain(P<0.000)and decreased function(P=0.043)since TJA postponement.CONCLUSION There is deterioration in health for patients,who have had elective procedures postponed during the COVID-19 pandemic.Waiting lists should be prioritized for urgency with the re-initiation of elective surgery.

日本少子化社会中的“待机儿童”:成因与消解

儿童照顾政策是日本应对日益加速的少子高龄化社会进程、提高社会成员生育意愿的重要环节。但"育儿支援新制度"、"幼保无偿化"等看似相当充裕的儿童照顾政策效果却未达预期:不仅新出生儿童数量没有实现增加,无法进入照顾机构的"待机儿童"也成为困扰日本政府与社会成员的新问题。由于日本儿童照顾体系中独特的保育所与幼儿园二元分立的历史构造,儿童照顾资源整合难度较大;更多女性参与劳动力市场导致家庭能够提供的儿童照顾减少,各类儿童照顾政策的实施又拉动了潜在的儿童照顾需求。日本的经验表明,应对少子化危机、解决待机儿童难题需要在增加儿童照顾供给总量、提高政策普惠性与公平性的同时,调整儿童照顾机构使用时间与使用限制等供给结构,提高儿童照顾对于社会成员的可得性与可及性。

生命法学领域之相关问题探析——论人体器官接受人的确定标准

人体器官的稀缺,使器官接受人的确定标准成为人体器官捐献和移植的核心。时间标准、地域标准、优先权标准和严格医学标准是确定准接受人的初始标准;若准接受人顺位发生冲突,应综合考量最优医学标准、家庭角色和社会服务因素。不得武断地认为老年人应当后于年轻人、品行不端的人当然轮后于他人接受器官移植手术;不应简单基于等待人的不良嗜好拒绝或者当然延长其等待时间;应当有区别地限制接受器官移植手术的次数。

体能测试的时间安排模型

本文讨论了某校学生体能测试的时间安排问题。从台阶试验的体检时间出发，将五个测试项目分为三大项，四大项，三大项与四大项（混合）编排三种方式建立动态规划排序模型，利用MATLAB得到各时段的各班安排顺序表。计算比较得出最佳方案是三大项与四大项（混合编排）。最后我们给出了在规定时间内各班安排顺序表的手工编排原则与方法。

High intensity focused ultrasound,liver disease and bridging therapy

High-intensity focused ultrasound(HIFU)is a noninvasive modality that uses an extracorporeal source of focused ultrasound energy.This technique was introduced by Lynn et al and is able to induce coagulative necrosis in selected tissues without damaging adjacent structures.Although HIFU has been studied for 50years,recent technological developments now allow its use for tumours of the liver,prostate and other sites.In liver disease,HIFU has been used to treat unresectable,advanced stages of hepatocellular carcinoma(HCC)and liver metastases.Hepatocellular carcinoma is a serious health problem worldwide and is endemic in some areas because of its association with hepatitis B and C viruses(in 20%of cases).Liver transplantation(LT)has become one of the best treatments available because it removes both the tumour and the underlying liver disease such as cirrhosis(which is present in approximately 80%of cases).The prerequisite for longterm transplant success depends on tumour load and strict selection criteria regarding the size and number of tumour nodules.The need to obtain the optimal benefit from the limited number of organs available has prompted strict selection criteria limited to only those patients with early HCC who have a better long-term outcome after LT.The so-called"bridging therapy"has the aim of controlling disease burden for patients who are on the organ transplant waiting list.Amongst various treatment options,transarterial chemoembolisation and radiofrequency ablation are the most popular treatment choices.Recently,Cheung et al demonstrated that HIFU ablation is a safe and effective method for the treatment of HCC patients with advanced cirrhosis as a bridging therapy and that it reduced the dropout rate from the liver transplant waiting list.In this commentary,we discuss the current value of HIFU in the treatment of liver disease,including its value as a bridging therapy,and examine the potential advantages of other therapeutic strategies.

Value of pretransplant albumin-bilirubin score in predicting outcomes after liver transplantation

BACKGROUND Due to the significant shortage of organs and the increasing number of candidates on the transplant waiting list, there is an urgent need to identify patients who are most likely to benefit from liver transplantation. The albuminbilirubin(ALBI) grading system was recently developed to identify patients at risk for adverse outcomes after hepatectomy. However, the value of the pretransplant ALBI score in predicting outcomes after liver transplantation has not been assessed.AIM To retrospectively investigate the value of the pretransplant ALBI score in predicting outcomes after liver transplantation.METHODS The clinical data of 272 consecutive adult patients who received donation after cardiac death and underwent liver transplantation at our centre from March 2012 to March 2017 were analysed in the cohort study. After the exclusion of patients who met any of the exclusion criteria, 258 patients remained. The performance of the ALBI score in predicting overall survival and postoperative complications after liver transplantation was evaluated. The optimal cut-off value of preoperative ALBI was calculated according to long-term survival status. The outcomes after liver transplantation, including postoperative complications and survival analysis, were measured.RESULTS The remaining 258 consecutive patients were included in the analysis. The median follow-up time was 17.30(interquartile range: 8.90-28.98) mo. Death occurred in 35 patients during follow-up. The overall survival rate was 81.0%.The preoperative ALBI score had a significant positive correlation with the overall survival rate after liver transplantation. The calculated cut-off for ALBI scores to predict postoperative survival was-1.48. Patients with an ALBI score >-1.48 had a significantly lower survival rate than those with an ALBI score ≤-1.48(73.7% vs 87.6%, P < 0.05), and there were no statistically significant differences in survival rates between patients with a model for end stage liver disease score ≥ 10 and < 10 and different Child-Pugh grades. In terms of the specific complications,a high ALBI score was associated with an increased incidence of biliary complications, intraabdominal bleeding, septicaemia, and acute kidney injury after liver transplantation(P < 0.05 for all).CONCLUSION The ALBI score predicts overall survival and postoperative complications after liver transplantation. The ALBI grading system may be useful in risk-stratifying patients on the liver transplant waiting list.

Selection of patients with hepatocellular carcinoma for livertransplantation:Past and future

The aim of liver transplantation(LT) for hepatocellular carcinoma(HCC) is to ensure a rate of disease-free survival similar to that of patients transplanted due to benign disease. Therefore, we are forced to adopt strict criteria when selecting candidates for LT and prioritizing patients on the waiting list(WL), to have clarified indications for bridging therapy for groups at risk for progression or recurrence, and to establish certain limits for downstaging therapies. Although the Milan criteria(MC) remain the standard and most employed criteria for indication of HCC patients for LT by far, in the coming years, criteria will be consolidated that take into account not only data regarding the size/volume and number of tumors but also their biology. This criteria will mainly include the alpha fetoprotein(AFP) values and, in view of their wide variability, any of the published logarithmic models for the selection of candidates for LT. Bridging therapy is necessary for HCC patients on the WL who meet the MC and have the possibility of experiencing a delay for LT greater than 6 mo or any of the known risk factors for recurrence. It is difficult to define single AFP values that would indicate bridging therapy(200, 300 or 400 ng/m L); therefore, it is preferable to rely on the criteria of a French AFP model score > 2. Other single indications for bridging therapy include a tumor diameter greater than 3 cm, more than one tumor, and having an AFP slope greater than 15 ng/m L per month or > 50 ng/m L for three months during strict monitoring while on the WL. When considering the inclusion of patients on the WL who do not meet the MC, it is mandatory to determine their eligibility for downstaging therapy prior to inclusion. The upper limit for this therapy could be one lesion up to 8 cm, 2-3 lesions with a total tumor diameter up to 8 cm, or a total tumor volume of 115 cm^3. Lastly, liver allocation and the prioritization of patients with HCC onthe WL should take into account the recently described HCC model for end-stage liver disease, which considers hepatic function, HCC size and the number and the log of AFP values. This formula has been calibrated with the survival data of non-HCC patients and produces a dynamic and more accurate assessment model.

Feasibility of using marginal liver grafts in living donor liver transplantation

Liver transplantation(LT) is one of the most effective treatments for end-stage liver disease caused by related risk factors when liver resection is contraindicated. Additionally,despite the decrease in the prevalence of hepatitis B virus(HBV) over the past two decades,the absolute number of HBs Ag-positive people has increased,leading to an increase in HBV-related liver cirrhosis and hepatocellular carcinoma. Consequently,a large demand exists for LT. While the wait time for patients on the donor list is,to some degree,shorter due to the development of living donor liver transplantation(LDLT),there is still a shortage of liver grafts. Furthermore,recipients often suffer from emergent conditions,such as liver dysfunction or even hepatic encephalopathy,which can lead to a limited choice in grafts. To expand the pool of available liver grafts,one option is the use of organs that were previously considered "unusable" by many,which are often labeled "marginal" organs. Many previous studies have reported on the possibilities of using marginal grafts in orthotopic LT; however,there is still a lack of discussion on this topic,especially regarding the feasibility of using marginal grafts in LDLT. Therefore,the present review aimed to summarize the feasibility of using marginal liver grafts for LDLT and discuss the possibility of expanding the application of these grafts.

Obesity and bariatric surgery in kidney transplantation:A clinical review

Obesity is increasing worldwide,and this has major implications in the setting of kidney transplantation.Patients with obesity may have limited access to transplantation and increased posttransplant morbidity and mortality.Most transplant centers incorporate interventions aiming to target obesity in kidney transplant candidates,including dietary education and lifestyle modifications.For those failing nutritional restriction and medical therapy,the use of bariatric surgery may increase the transplant candidacy of patients with obesity and endstage renal disease(ESRD)and may potentially improve the immediate and late outcomes.Bariatric surgery in ESRD patients is associated with weight loss ranging from 29.8% to 72.8% excess weight loss,with reported mortality and morbidity rates of 2% and 7%,respectively.The most commonly performed bariatric surgical procedures in patients with ESRD and in transplant patients are laparoscopic sleeve gastrectomy(LSG)and laparoscopic Roux-en-Y gastric bypass.However,the correct timing of bariatric surgery and the ideal type of surgery have yet to be determined,although pretransplant LSG seems to be associated with an acceptable risk-benefit profile.We review the impact of obesity on kidney transplant candidates and recipients and in potential living kidney donors,exploring the potential impact of bariatric surgery in addressing obesity in these populations,thereby potentially improving posttransplant outcomes.

Liver transplant allocation policies and outcomes in United States: A comprehensive review

Liver transplant allocation policies in the United States has evolved over 3 decades.The donor liver organs are matched,allocated and procured by the Organ Procurement and Transplantation Network which is administered by the United Network of Organ Sharing(UNOS),a not-for-profit organization governed by the United States human health services.We reviewed the evolution of liver transplant allocation policies.Prior to 2002,UNOS used Child-Turcotte-Pugh score to list and stratify patients for liver transplantation(LT).After 2002,UNOS changed its allocation policy based on model for end-stage liver disease(MELD)score.The serum sodium is the independent indicator of mortality risk in patients with chronic liver disease.The priority assignment of MELD-sodium score resulted in LT and prevented mortality on waitlist.MELD-Sodium score was implemented for liver allocation policy in 2016.Prior to the current and most recent policy,livers from adult donors were matched first to the status 1A/1B patients located within the boundaries of the UNOS regions and donor-service areas(DSA).We reviewed the disadvantages of the DSA-based allocation policies and the advantages of the newest acuity circle allocation model.We then reviewed the standard and non-standard indications for MELD exceptions and the decision-making process of the National Review Liver Review Board.Finally,we reviewed the liver transplant waitlist,donation and survival outcomes in the United States.

Liver transplantation in adults:Choosing the appropriate timing

Liver transplantation is indicated in patients with acute liver failure,decompensated cirrhosis,hepatocellular carcinoma and rare liver-based genetic defects that trigger damage of other organs.Early referral to a transplant center is crucial in acute liver failure due to the high mortality with medical therapy and its unpredictable evolution.Referral to a transplant center should be considered when at least one complication of cirrhosis occurs during its natural history.However,because of the shortage of organ donors and the short-term mortality after liver transplantation on one hand and the possibility of managing the complications of cirrhosis with other treatments on the other,patients are carefully selected by the transplant center to ensure that transplantation is indicated and that there are no medical,surgical and psychological contraindications.Patients approved for transplantation are placed on the transplant waiting list and prioritized according to disease severity.Thus,the appropriate timing of transplantation depends on recipient disease severity and,although this is still a matter of debate,also on donor quality.These two variables are known to determine the "transplant benefit"(i.e.,when the expected patient survival is better with,than without,transplantation) and should guide donor allocation.

Kidney transplantation in older recipients:Preemptive high KDPI kidney vs lower KDPI kidney after varying dialysis vintage

AIM To evaluate the outcomes of transplanting marginal kidneys preemptively compared to better-quality kidneys after varying dialysis vintage in older recipients.METHODS Using OPTN/United Network for Organ Sharing database from 2001-2015, we identified deceased donor kidney(DDK) transplant recipients > 60 years of age who either underwent preemptive transplantation of kidneys with kidney donor profile index(KDPI) ≥ 85%(marginal kidneys) or received kidneys with KDPI of 35%-84%(better quality kidneys that older wait-listed patients would likely receive if waited longer) after being on dialysis for either 1-4 or 4-8 years. Using a multivariate Cox model adjusting for donor, recipient and transplant related factors-overall and death-censored graft failure risks along with patient death risk of preemptive transplant recipients were compared to transplant recipients in the 1-4 and 4-8 year dialysis vintage groups.RESUTLS The median follow up for the whole group was 37 mo(interquartile range of 57 mo). A total of 6110 DDK transplant recipients above the age of 60 years identified during the study period were found to be eligible to be included in the analysis. Among these patients350 received preemptive transplantation of kidneys with KDPI ≥ 85. The remaining patients underwent transplantation of better quality kidneys with KDPI 35-84% after being on maintenance dialysis for either 1-4 years(n = 3300) or 4-8 years(n = 2460). Adjusted overall graft failure risk and death-censored graft failure risk in preemptive high KDPI kidney recipients were similar when compared to group that received lower KDPI kidney after being on maintenance dialysis for either 1-4 years(HR 1.01, 95%CI: 0.90-1.14, P = 0.84 and HR 0.96, 95%CI: 0.79-1.16, P = 0.66 respectively) or 4-8 years(HR 0.82, 95%CI: 0.63-1.07, P = 0.15 and HR 0.81, 95%CI: 0.52-1.25, P = 0.33 respectively). Adjusted patient death risk in preemptive high KDPI kidney recipients were similar when compared to groups that received lower KDPI kidney after being on maintenance dialysis for 1-4 years(HR 0.99, 95%CI: 0.87-1.12, P = 0.89) but lower compared to patients who were on dialysis for 4-8 years(HR 0.74, 95%CI: 0.56-0.98, P = 0.037).CONCLUSION In summary, our study supports accepting a "marginal" quality high KDPI kidney preemptively in older waitlisted patients thus avoiding dialysis exposure.

肝移植治疗门静脉高压症的作用与地位及需要注意的问题

肝移植是治疗门静脉高压症终末期肝病唯一有效的方法。但由于临床上供肝严重匮乏，实际应用时还无法满足庞大的需求。把握好门静脉高压症肝移植的指征和时机，科学处理好移植等待期间或加入移植等待名单前各类并发症，可以避免不必要的肝移植、降低移植等待名单病死率。门静脉高压症肝移植围术期处理有其特殊之处及需要注意的问题，了解并掌握这些特殊之处，处理好这些需要注意的问题，对提高门静脉高压症肝移植成功率、加速肝移植术后康复、降低手术死亡率有着十分重要的意义。

PKI中CRL撤消延迟的研究

首先建立了使用 CRL发布证书撤消信息的数学模型 .在对模型进行分析得基础上 ,对撤消延迟进行了分析 ,得到了撤消延迟的表达式并提出了发布 CRL的最佳方法 .最后给出了计算机仿真结果 ,对理论分析正确性进行了验证 .