Graft-to-recipient weight ratio lower to 0.7% is safe without portal pressure modulation in right-lobe living donor liver transplantation with favorable conditions

BACKGROUND: The low graft-to-recipient weight ratio(GRWR) in adult-to-adult living donor liver transplantation(LDLT) is one of the major risk factors affecting graft survival. The goal of this study was to evaluate whether the lower limit of the GRWR can be safely reduced without portal pressure modulation in right-lobe LDLT. METHODS: From 2005 to 2011, 317 consecutive patients from a single institute underwent LDLT with right-lobe grafts without portal pressure modulation. Of these, 23 had a GRWR of less than 0.7%(group A), 27 had a GRWR of ≥0.7%, 【0.8%(group B), and 267 had a GRWR of more than and equal to 0.8%(group C). Medical records, including recipient, donor, operation factors, laboratory findings and complications were reviewed retrospectively. RESULTS: The baseline demographics showed low model for end-stage liver disease score(mean 16.3±8.9) and high percentage of hepatocellular carcinoma(231 patients, 72.9%). Three groups by GRWR demonstrated similar characteristics except recipient body mass index and donor gender. For smallforsize syndrome, there were 3(13.0%) in group A, 1(3.7%) in group B, and 2 patients(0.7%) in group C(P【0.001). Hepatic artery thrombosis was more frequently observed in group A than in groups B and C(8.7% vs 3.7% vs 1.9%, P=0.047). However, among the three groups, graft survival rates at 1 year(100% vs 96.3% vs 93.6%) and 3 years(91.7% vs 73.2% vs 88.1%) were not different(P=0.539). In laboratory measurements,there was no group difference in total bilirubin and albumin. However, prothrombin time was longer in group A within postoperative 1 week and platelet count was lower in groups A and B within postoperative 1 month. CONCLUSION: A GRWR lower to 0.7% is safe and does not need to modulate portal pressure in adult-to-adult LDLT using the right-lobe in favorable conditions including low model for end-stage liver disease score.

Living donor liver transplantation with body-weight more or less than 10 kilograms

AIM: To compare the outcomes of pediatric patients weighing less than or more than 10 kg who underwent liver transplantation.METHODS: Data for 196 pediatric patients who underwent living donor liver transplantation between June 1994 and February 2011 were reviewed retrospectively.The information for each patient was anonymized and de-identified before analysis. The data included information regarding the pre-transplant conditions, intraoperative fluid replacement and outcomes for each patient. The 196 patients were divided into two groups: those with body weights of less than 10 kg were included in group 1(G1; n =101), while those with body weights of more than 10 kg were included in group 2(G2; n = 95). For each group, the patients' ages, body weights, heights,pediatric end stage liver disease scores, anesthesia times, and warm and cold ischemic times were analyzed. In addition, between-group comparisons were also made. Mann-Whitney U tests were used to compare all the variables except for complications and survival rates, which were analyzed using χ 2 tests and Kaplan-Meier tests, respectively.RESULTS: The general medical conditions of the G1patients were worse than those of the G2 patients, as shown by the higher pediatric end stage liver disease scores and poorer Z-scores. In addition, the preoperative Hb and serum albumin levels were all lower for the G1 patients than for the G2 patients. The G1 patients also had significantly more intraoperative blood loss than the G2 patients. In addition, the intraoperative fluid requirements for the G1 patients,including leukocyte poor red blood cell transfusions,5% albumin infusions and crystalloid infusions, were significantly higher than those for the G2 patients. The risk of intraoperative portal vein thrombosis was higher for the patients in G1 than for those in G2. However,the one-year survival rates(95.9% and 96.8% for G1 and G2, respectively) and three-year survival rates(94.9% and 94.6% for G1 and G2, respectively) for both groups were similar.CONCLUSION: Patients weighing less than 10 kg typically have poorer conditions, but their survival rates are comparable to those of children weighing more than 10 kg.

Single vs dual(en bloc) kidney transplants from donors ≤ 5 years of age: A single center experience

AIM: To compare outcomes between single and dual en bloc(EB) kidney transplants(KT) from small pediatric donors. METHODS: Monocentric nonprospective review of KTs from pediatric donors ≤ 5 years of age. Dual EB KT was defined as keeping both donor kidneys attached tothe inferior vena cava and aorta, which were then used as venous and arterial conduits for the subsequent transplant into a single recipient. Donor age was less useful than either donor weight or kidney size in decision-making for kidney utilization as kidneys from donors < 8 kg or kidneys < 6 cm in length were not transplanted. Post-transplant management strategies were standardized in all patients.RESULTS: From 2002-2015, 59 KTs were performed including 34 dual EB and 25 single KTs. Mean age of donors(17 mo vs 38 mo, P < 0.001), mean weight(11.0 kg vs 17.4 kg, P = 0.046) and male donors(50% vs 84%, P = 0.01) were lower in the dual EB compared to the single KT group, respectively. Mean cold ischemia time(21 h), kidney donor profile index(KDPI; 73% vs 62%) and levels of serum creatinine(SCr, 0.37 mg/d L vs 0.49 mg/d L, all P = NS) were comparable in the dual EB and single KT groups, respectively. Actuarial graft and patient survival rates at 5-years follow-up were comparable. There was one case of thrombosis resulting in graft loss in each group. Delayed graft function incidence(12% dual EB vs 20% single KT, P = NS) was slightly lower in dual EB KT recipients. Initial duration of hospital stay(mean 5.4 d vs 5.6 d) and the one-year incidences of acute rejection(6% vs 16%), operative complications(3% vs 4%), and major infection were comparable in the dual EB and single KT groups, respectively(all P = NS). Mean 12 mo SCr and abbreviated MDRD levels were 1.17 mg/d L vs 1.35 mg/d L and 72.5 m L/min per 1.73 m^2 vs 60.5 m L/min per 1.73 m^2(both P = NS) in the dual EB and single KT groups, respectively. CONCLUSION: By transplanting kidneys from young pediatric donors into adult recipients, one can effectively expand the limited donor pool and achieve excellent medium-term outcomes.

Outcomes of adult patients adopting small-for-size grafts in living donor liver transplantation: A systematic review and meta-analysis

Background: Small-for-size graft(SFSG) has emerged as one of the very contentions in adult-to-adult living donor liver transplantation(LDLT) as a certain graft size is related to recipients’ prognosis. Graftto-recipient weight ratio(GRWR)≥0.8% was considered as a threshold to conduct LDLT. However, this also has been challenged over decades as a result of technique refinements. For a better understanding of SFSG in practice, we conducted this meta-analysis to compare the perioperative outcomes and long-term outcomes between patients adopting the grafts with a lower volume(GRWR < 0.8%, SFSG group) and sufficient volume(GRWR ≥ 0.8%, non-SFSG group) in adult-to-adult LDLT. Data sources: The studies comparing recipients adopting graft with a GRWR < 0.8% and ≥ 0.8% were searched by three authors independently in Pub Med, Web of Science, Embase, the Cochrane Library, MEDLINE and Google Scholar databases until September 2018 and data were analyzed by RevMan 5.3.5. Results: Sixteen studies with a total of 3272 subjects were included in this meta-analysis. In terms of small-for-size syndrome(SFSS), no significant difference was found in subjects enrolled after year 2010(before 2010, OR = 3.00, 95% CI: 1.69–5.35, P = 0.0002;after 2010, OR = 1.23, 95% CI: 0.79–1.90, P = 0.36;P for interaction: 0.02). There was no significant difference in operative duration, blood loss, cold ischemia time, biliary complications, acute rejection, postoperative bleeding, hospitalization time, perioperative mortality, and 1-, 3-and 5-year overall survival rates between two groups. Conclusions: This meta-analysis suggested that adopting SFSG in adult LDLT has comparable outcomes to those with non-SFSG counterparts since 2010.

Outcome of patients undergoing right lobe living donor liver transplantation with small-for-size grafts

AIM:To investigate the outcome of living donor liver transplantation(LDLT)recipients transplanted with small-for-size grafts(SFSGs).METHODS:Between November 2001 and December2010,196 patients underwent LDLT with right lobe liver grafts at our center.Recipients were divided into 2 treatment groups:group A with an actuarial graft-to-recipient weight ratio(aGRWR)<0.8%(n=45)and group B with an aGRWR≥0.8%(n=151).We evaluated serum liver function markers within 4 wk after transplantation.We also retrospectively evaluated the outcomes of these patients for potential effects related to the recipients,the donors and the transplantation procedures based upon a review of their medical records.RESULTS:Small-for-size syndrome(SFSS)developed in 7 of 45 patients(15.56%)in group A and 9 of 151patients(5.96%)in group B(P=0.080).The levels of alanine aminotransferase and aspartate aminotransferase in group A were higher than those in group B during early period after transplantation,albeit not significantly.The cumulative 1-,3-and 5-year liver graft survival rates were 82.22%,71.11%and 71.11%for group A and 81.46%,76.82%,and 75.50%for group B patients,respectively(P=0.623).However,univariate analysis of risk factors associated with graft survival in group A demonstrated that the occurrence of SFSS after LDLT was the only significant risk factor affecting graft survival(P<0.001).Furthermore,multivariate analysis of our data did not identify any additional significant risk factors accounting for poor graft survival.CONCLUSION:Our study suggests that LDLT recipients with an aGRWR<0.8%may have liver graft outcomes comparable to those who received larger size grafts.Further studies are required to ascertain the safety of using SFSGs.

Splenectomy in living donor liver transplantation and risk factors of portal vein thrombosis

Background:Graft inflow modulation(GIM)during adult-to-adult living donor liver transplantation(LDLT)is a common strategy to avoid small-for-size syndrome,and some transplant surgeons attempt small size graft strategy with frequent GIM procedures,which are mostly performed by splenectomy,in LDLT.However,splenectomy can cause serious complications such as portal vein thrombosis and overwhelming postsplenectomy infection.Methods:Forty-eight adult-to-adult LDLT recipients were enrolled in this study and retrospectively reviewed.We applied the graft selection criteria,which routinely fulfill graft-to-recipient weight ratio≥0.8%,and consider GIM as a backup strategy for high portal venous pressure(PVP).Results:In our current strategy of LDLT,splenectomy was performed mostly due to hepatitis C and splenic arterial aneurysms,but splenectomy for GIM was intended to only one patient(2.1%).The final PVP values≤20 mmHg were achieved in all recipients,and no significant difference was observed in patient survival or postoperative clinical course based on whether splenectomy was performed or not.However,6 of 18 patients with splenectomy(33.3%)developed postsplenectomy portal vein thrombosis(PVT),while none of the 30 patients without splenectomy developed PVT after LDLT.Splenectomy was identified as a risk factor of PVT in this study(P<0.001).Our study revealed that a lower final PVP could be risk factor of postsplenectomy PVT.Conclusions:Using sufficient size grafts was one of the direct solutions to control PVP,and allowed GIM to be reserved as a backup procedure.Splenectomy should be avoided as much as possible during LDLT because splenectomy was found to be a definite risk factor of PVT.In splenectomy cases with a lower final PVP,a close follow-up is required for early detection and treatment of PVT.

1例扩张型心肌病供受体体重不匹配儿童心脏移植术后护理

经多学科协作,对宁夏医科大学总医院2022年3月收治的1例扩张型心肌病患儿密切监测血流动力学变化,进行规范化的疼痛管理,实施心脏围术期加速康复外科(ERAS)护理,保护性隔离,积极进行心理干预。结果患儿术后移植心脏功能恢复良好,出院前生命体征平稳。出院后随访3个月,患儿病情稳定,未发生排斥反应。

PE-UHMW聚合用氧基硅烷内给电子体Ziegler-Natta催化剂的制备及应用

采用实验室自制的两种复合型氧基硅烷内给电子体:二甲基二(2-酚基乙氧基)硅烷(IED1)和二甲基二(2-氯乙氧基)硅烷(IED2),将两种内给电子体配置Ziegler-Natta催化剂并进行乙烯的催化聚合以制备超高分子量聚乙烯(PE-UHMW)。考察了两种内给电子体加入对Ziegler-Natta催化剂的载钛量、催化剂活性、催化剂的微观形貌及聚合物分子量等因素的影响,并考察催化剂加入量、聚合温度、聚合时间、助催化剂加入量对PE-UHMW聚合效果的影响。由于IED1结构中含有4个含氧基团,电子云密度高于IED2,因此IED1对催化剂活性以及聚合物分子量影响较大。最终确定PE-UHMW聚合工艺条件为:以IED1为内给电子体,催化剂加入量为12 mg/L,IED1与载体氯化镁的物质的量之比为1∶4,聚合温度为75℃,聚合时间为2 h,催化剂中Al/Ti物质的量之比为80。在此工艺条件下催化剂的催化效率为17.1 kg/(g·h),催化剂载钛量为5.8%,PE-UHMW堆密度为0.3 g/cm^(3),PE-UHMW分子量为4.0×10^(6)。

氢气和外给电子体对负载型Ziegler-Natta催化丁烯-1聚合的影响

研究了氢气和烷氧基硅烷类外给电子体对负载型Ziegler—Natta丁烯-1专用催化剂聚合性能的影响，并采用GPC、DSC和偏光显微镜，对聚合物进行了分析。结果表明：聚合活性随氢气加入量的增加先上升后下降；不同外给电子体时，以加入DCPMS时催化剂活性和产物等规度最高；降低氢气加入量和增大外给电子体烷基空间体积均可使聚丁烯-1相对分子质量增大。聚合物的相对分子质量对聚丁烯-1的结晶影响明显，在Mw-23．5×10^4g／mol时的聚丁烯-1的熔点较高、结晶度也高。

外给电子体对聚丙烯性能的影响

综述了用Ziegler-Natta催化剂制备聚丙烯时加入的外给电子体对聚丙烯等规度、分子量分布和熔融指数的影响,并深入讨论了不同外给电子体组合对聚丙烯性能的影响。采用合适的外给电子体组合可以制备出高熔融指数、宽分子量分布的高性能聚丙烯。

宽分子量分布、宽等规指数分布聚丙烯的制备及在高速BOPP中的应用

分析了非对称外给电子体及非对称加氢气的聚合方法对聚丙烯分子结构的影响,并用DSC和GPC等表征手段对聚丙烯结构进行分析。结果表明:非对称外给电子体技术制备的聚丙烯的等规指数分布较宽,具有低等规度的大分子和高等规度的小分子的特征,使聚丙烯等规序列分布均匀化,有利于提高薄膜挺度,并提高薄膜厚度均匀性,而非对称加氢技术制备的聚丙烯分子量分布较宽,保证了聚丙烯熔体高速拉伸的稳定性。非对称外给电子体和非对称加氢技术制备的聚丙烯具有高速拉膜稳定性好、成膜率高、无破膜,模头无烟雾和油性物质、不结焦,厚薄均匀、表面平整性好,挺度高、透明性好的优点,成功应用于高速、高挺度BOPP工业化生产。

体重对婴幼儿活体肝移植预后的影响

目的评估婴幼儿体重与活体肝移植预后的关系,探讨体重对预后的影响。方法选取2006年10月至2010年12月上海交通大学医学院附属仁济医院实施的44例婴幼儿活体肝移植,术前诊断均为胆道闭锁,移植物类型均为肝左外叶。回顾性分析受者性别、术龄、体重、PELD评分、葛西手术史、GRWR、供肝冷缺血时间、术中失血量、围术期并发症及累积生存率等临床数据,并根据体重将受者分为两组:第1组,体重<7.55 kg(n=19);第2组,体重>7.55 kg(n=25)。随访截止时间为2011年2月,平均随访时间为(17.5±13.3)月。结果 44例受者死亡9例,总体1年累积生存率为81.2%。两组受者性别、PELD评分、葛西手术史、GRWR、供肝冷缺血时间、术中失血量及围术期并发症等的分布情况无统计学差异,受者术龄分布存在显著性差异。结果对比显示,第1组和第2组的1年累积生存率分别为68.0%和91.2%。结论体重是影响婴幼儿活体肝移植预后的因素之一,低体重受者的生存率低于高体重受者,术前应尽量促进患儿的生长发育以改善其预后。

双份无关供者脐血移植治疗成人体重急性白血病

目的探索非亲缘性双份脐血移植(CBT)治疗成人体重急性白血病的可行性及并发症的防治。方法对3例成人体重(>50kg)急性白血病患者(1例ALL-NR,2例ANLL-CR1)进行双份无关供者脐血移植,预处理方案采用白消安/环磷酰胺(BU/Cy)方案加抗胸腺细胞球蛋白(ATG),移植物抗宿主病(GVHD)的预防用环胞菌素A(CsA)、甲氨蝶呤(MTX)及霉酚酸酯(MMF)±赛尼哌(Zenapax);肝静脉闭塞病(VOD)的预防用低分子右旋糖酐及肝素。结果例1、例2中性粒细胞绝对值(ANC)>0.5×109/L的时间分别为+17d、+16d,血小板>50×109/L的时间为+40d、+37d;DNA指纹图分别在+18d、+21d外周血VNTR检测显示为供者1型;例1+33d骨髓象完全缓解;+120d出现复发。例2染色体核型为46,XY;于+55d血型转为A型,目前已无病存活50个月。例3于+27d回输自体外周血干细胞,恢复自身造血,目前无病生存46个月。结论对于成人体重受者接受HLA配型部分相合的2份脐血移植在临床上是可行的。

供受体体重不匹配儿童心脏移植的围手术期处理

目的 总结 1例 13岁终末期扩张型心肌病儿童施行原位心脏移植术 ,因供受体体重不匹配所带来的围手术期有关问题的处理经验。方法 供体 2 8岁 ,体重 63kg ,主动脉直径 2 .8cm。受体 13岁 ,体重37kg。主动脉直径 1.7cm。术中采用主动脉成形处理供受体主动脉直径不匹配。术后采用大剂量血管扩张剂控制成人心脏移植到儿童所带来的高心输出量并发症 ,并针对儿童代谢快的特点调整免疫抑制剂的用量。结果 术后血流动力学稳定。第 12天心肌活检病理学检查无排斥反应 ,31d出院 ,随访 18个月 ,心功能良好。结论 扩张型心肌病的儿童 ,可采用成人供心施行心脏移植术。

分子量及酰基供体对酶促魔芋葡甘聚糖酰化反应的影响

研究了在有机介质叔丁醇中魔芋葡甘聚糖(KGM)的分子量及酰基供体对固定化脂肪酶Novozym 435催化KGM乙酰化反应的影响.KGM的分子量对酶促其酰化反应的活性及产物取代度有显著影响.随着KGM分子量的增大,酶催化反应的速率逐渐下降,产物的取代度逐渐减小.KGM分子量对该反应的影响与不同分子量KGM的溶解度、体系粘度、空间位阻及颗粒形态等因素有关.以不同链长的脂肪酸乙烯酯为酰基供体时,随着酰基供体中脂肪酸碳链的增长,酶促KGM酰化反应速率逐渐下降,产物的取代度逐渐减小,且该酰化反应具有高度的区域选择性,反应均发生在C6-OH上.

酮/酯复配内给电子体催化剂的制备及其乙烯聚合评价

用酮类和二酯类为复配内给电子体制备了一种高效乙烯聚合催化剂,用FTIR分析了单个内给电子和复配内给电子体对催化剂结构的影响,结果表明3种催化剂中给电子性能为邻苯二甲酸>邻苯二甲酸/二异丁酯乙酰丙酮>二异丁酯乙酰丙酮。用凝胶渗透色谱(GPC)和差示扫描量热仪(DSC)对3种催化剂所制备的聚乙烯进行了表征,与单个内给电子体催化剂制备的聚乙烯相比,复配内给电子体催化剂所制备的聚乙烯具有更高的聚合活性,更明显的"共单体效应"和更宽的相对分子量分布。

成人—成人间活体右半肝移植

目的报道对高度紧急的成人终末期肝病患者进行活体右半肝移植的经验。病人及方法自１９９６年５月到１９９８年８月，对１５例高度紧急的成人终末期肝病患者进行了活体右半肝移植。１３例术前在重症监护病房，２例因肝病的并发症而住院。供体和受体的平均体重分别为５８ｋｇ（４１～８４ｋｇ）和６６ｋｇ（４５～１００ｋｇ），９例受体体重大于供体，最低的供体同受体体重比例为０．６２∶１。如果估计左肝叶的体重小于受体预计标准肝重量的４０％，则选择右半肝。结果供体手术的平均失血量为８００ｍｌ（３００～１６００ｍｌ），供体的平均住院时间为１３天（６～３８天）。１４例供体未输血。２例供体术后发生并发症，１例是切口疝，另１例是胆道狭窄，他们在出院后需要接受第二次手术。移植肝的平均重量为７１９克（４９０～１１４０ｇ），所有移植肝均立即恢复功能，病人精神状态康复，凝血酶原时间恢复正常。１１例受体需要再次手术探查。２例（１３．３％）患者死亡，１例在术后１６天死于全身性念珠菌感染。另１例在术后２２天死于门静脉栓塞。１３例（８６．７％）受体存活，生活质量良好。结论认为由一支具有丰富肝切除及肝移植经验的医生队伍来行右半肝的活体肝移植能达到较好的结果，采用?

以聚丙二醇二苯甲酸酯为给电子体的丙烯聚合催化剂

采用聚丙二醇二苯甲酸酯(PPGDB)为内给电子体制备了一种新的丙烯聚合催化剂MgCl2/PPGDB/TiCl4.该催化剂用于丙烯聚合时,除了具有与以邻苯二甲酸二异丁酯为给电子体的催化剂相当的活性和立体定向性外,其特点在于所得产物的分子量分布较宽(Mw/Mn>8.0).采用红外光谱研究了催化剂中PPGDB与MgCl2的作用机制,结果表明PPGDB中的酯官能团和醚官能团可同时与MgCl2配位.这种双官能团的配位作用是所得聚合物分子量分布较宽的主要原因.

超高分子量聚丙烯的制备

超高分子量聚丙烯(UHMWPP)是一种黏均分子量百万以上,具有超高的强度、超高的耐磨性、较强的抗氧化能力的热塑性工程塑料,可用于制备高强度、高模量、耐腐蚀、抗冲击、耐应力开裂的聚丙烯产品。本工作的目的在于制备出分子量超过200万的聚丙烯,将其用作3D打印材料来解决由于分子链较长引起高熔体黏度和低流动性而导致加工难成型问题。本工作基于传统的Ziegler-Natta催化剂,对主催化剂进行金属离子和有机物的负载,通过控制丙烯的链转移来控制聚丙烯的分子量,并且在聚合反应过程中不加入氢气(带有活性氢的物质),以防止其成为聚合反应的终止剂。研究了聚合反应温度、聚合反应时间、助催化剂和外给电子体对聚丙烯分子量的影响。采用黏度法、升温淋洗分级法等表征了制备的聚丙烯分子量。通过聚合工艺优化,在聚合反应温度70℃、聚合反应时间60min、助催化剂三异丁基铝、外给电子体P Donor下,最终制备出了黏均分子量超过204万的超高分子量聚丙烯。