Surgical Video Review of Warm Ischemia Time during Laparoscopic Partial Nephrectomy and Impact on Positive Surgical Margins and Postoperative Complications

Introduction: A surgical video review is an emerging tool for quality improvement, especially in complex surgeries such as laparoscopic partial nephrectomy (LPN). Assessing and measuring the warm ischemia time (WIT) during LPN by dividing it into the time used for resection (ResT), time used for reconstruction (RecT) and intermediate time (IntT) has not been performed before. This study aimed to analyze the factors that can influence all these surgical times and assess their impact on positive surgical margins (PSM) and complication rates. Methods: We evaluated 36 surgical video recordings from patients who underwent LPN and measured WIT, ResT, RecT and IntT with a stopwatch. Factors such as tumor characteristics and surgeon experience were also recorded. SPSS software was used to identify the predictor factors for all these surgical times and to correlate the ResT with PSM and RecT with the complication rate. Results: We recorded a mean WIT of 887 seconds. The mean ResT, RecT and IntT were 240 (27.2% of WIT), 473 (52.6% of WIT) and 173 s (20.2% of WIT), respectively. We found a moderate correlation between the WIT (p = 0.030), IntT and the R.E.N.A.L. score (p = 0.019). The surgeon with less than 100 LPN had significantly longer WIT, ResT, and RecT values, with means of 977 (p = 0.015), 268 (p = 0.019) and 530 seconds (p = 0.015), respectively. No correlation was found between ResT and PSM (p = 0.418);however, a strong correlation was found between RecT and the probability of developing complications (p = 0.012). Conclusion: The surgeon’s experience influences WIT, ResT, and RecT, but not IntT, which depends on tumor complexity. RecT affects the probability of developing complications. IntT represents a fifth of the WIT and efforts to reduce the WIT should focus on reducing the IntT for complex tumors, by improving surgical planning.

Biliary tract injury caused by different relative warm ischemia time in liver transplantation in rats

BACKGROUND: There is a controversy over the degree of liver and biliary injury caused by the period of secondary warm ischemia. A liver autotransplantation model was adopted because it excludes the effects of infection and immunological rejection on bile duct injury. This study was undertaken to assess biliary tract injury caused by relative warm ischemia (secondary warm ischemia time in the biliary tract) and reperfusion. METHODS: One hundred and two rats were randomly divided into 5 groups: group I (control); groups 11 to V, relative warm ischemia times of 0 minute, 30 minutes, I hour and 2 hours. In addition to the levels of serum alkaline phosphatase, and total bilirubin, pathomorphology assessment and TUNEL assay were performed to evaluate biliary tract damage. RESULTS: Under the conditions that there were no significant differences in warm ischemia time, cold perfusion time and anhepatic phase, group comparisons showed statistically significant differences. The least injury occurred in group H (portal vein and hepatic artery reperfused simultaneously) but the most severe injury occurred in group V (biliary tract relative warm ischemia time 2 hours). CONCLUSIONS: Relative warm ischemia is one of the factors that result in bile duct injury, and the relationship between relative warm ischemia time the bile injury degree is time-dependent. Simultaneous arterial and portal reperfusion is the best choice to avoid the bile duct injury caused by relative warm ischemia. (Hepatobiliary Pancreat Dis Int 2009; 8: 247-254)

Dynamical changing patterns of histological structure and ultrastructure of liver graft undergoing warm ischemia injury from non-heart-beating donor in rats

AIM： To investigate the histological and ultra-structural characteristics of liver graft during different of warm ischemia time （WIT） in rats and to predict the maximum limitation of liver graft to warm ischemia. METHODS： The rats were randomized into 7 groups undergoing warm ischemia injury for 0, 10, 15, 20, 30, 45 and 60 min, respectively. All specimens having undergone warm ischemia injury were investigated dynamically by light and electron microscopy, and histochemistry staining. After orthotopic liver transplantation （OLT）, the recovery of morphology of liver grafts after 6, 24 and 48 h was observed. RESULTS： The donor liver from non-heart-beating donors （NHBD） underwent ischemia injury both in the warm ischemia period and in the reperfusion period. Morphological changes were positively related to warm ischemia injury in a time-dependent manner during the reperfusion period. The results demonstrated that different degrees of histocyte degeneration were observed when WIT was within 30 min, and became more severe with the prolongation of WIT, no obvious hepatocyte necrosis was noted in any specimen. In the group undergoing warm ischemia injury for 45 min, small focal necrosis occurred in the central area of hepatic Iobule first. In the group undergoing warm ischemia injury for 60 rain, patchy or diffused necrosis was observed and the area was gradually extended, while hepatic sinusoid endothelial cells were obviously swollen. Hepatic sinusoid was obstructed and microcirculation was in disorder.CONCLUSION： The rat liver graft undergoing warm ischemia injury is in the reversible stage when the WIT is within 30 min. The 45 min WIT may be a critical point of rat liver graft to endure warm ischemia injury. When the WIT is over 60 min, the damage is irreversible.

Influence of warm ischemia injury on hepatic functional status and survival of liver graft in rats

OBJECTIVES: To investigate the changing patterns of functional and histological status, observe the posttransplantation survival of liver graft under different warm ischemia time (WIT) in rats, and determine the maximum limitation of liver graft to warm ischemia. METHODS: According to WIT, the rats were randomized into 7 groups, with WIT of 0, 10, 15, 20, 30, 45, 60 minutes respectively. Serum concentrations of alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase were measured at 1, 2, 3 and 5 days after orthotopic liver transplantation respectively. Liver graft specimens were observed histopathologically at the same interval. The rats' survival in each subgroup was observed. RESULTS: In terms of graft survival, there was no significant difference between subgroups within 30-minute WIT. In the group with 30-minute WIT, the recipient rats' survival rate was 83.3% (10/12) at one week, 58.3% (7/12) at one month, and 50.0% (6/12) at 3 months. In the group with 45-minute WIT, the recipient rats' survival rate was 66.7% (8/12) at one week, 33.3% (4/12) at one month, and 8.3% (1/12) at 3 months, whereas only 8.3% (1/12) of the rats had one-week survival in the group with 60-minute WIT. CONCLUSIONS: These results indicate that rat liver graft could be safely subject to warm ischemia within 30 minutes. When WIT is prolonged to 45 minutes, the recipients long-term survival is severely insulted, and both function and histological structure of liver graft may develop irreversible damage when WIT is prolonged to 60 minutes.

Dynamical changing patterns of glycogen and enzyme histochemical activities in rat liver graft undergoing warm ischemia injury

AIM:To investigate the changing patterns of glycogen and enzyme histochemical activities in rat liver graft under a different warm ischemia time (WIT) and to predict the tolerant time limitation of the liver graft to warm ischemia injury. METHODS: The rats were randomized into five groups, WIT was 0,15,30,45,60 min, respectively, and histochemical staining of liver graft specimens was observed. The recovery changes of glycogen and enzyme histochemistry activities were measured respectively 6 and 24 h following liver graft implantation. RESULTS: The activities of succinic dehydrogenase, cytochrome oxidase, apyrase (Mg++-ATPase) and content of glycogen were decreased gradually after different WIT in a time-dependent manner. The changes were significant when WIT was over 30 min. CONCLUSION: Hepatic injury is reversible within 30 min of warm ischemia injury. Glycogen and enzyme histochemistry activities of liver grafts and their recovery potency after reperfusion may serve as criteria to evaluate the quality of liver grafts.

Effects of warm ischemia time on biliary injury in rat liver transplantation

AIM:To investigate the effect of different secondary warm ischemia time (SWIT) on bile duct injury in livertransplanted rats. METHODS:Forty-eight male inbred Sprague-Dawley rats were randomly assigned into four groups:a shamoperation group and three groups with secondary biliary warm ischemia time of 0 min, 10 min and 20 min. A rat model of autologous liver transplantation under ether anesthesia was established, and six rats were killed in each group and blood samples and the median lobe of the liver were collected for assay at 6 h and 24 h after hepatic arterial reperfusion. RESULTS:With prolongation of biliary warm ischemia time, the level of vascular endothelial growth factor-A was significantly decreased, and the value at 24 h was higher than that at 6 h after hepatic arterial reperfusion, but with no significant difference. The extended biliary SWIT led to a significant increase in bile duct epithelial cell apoptosis, and a decrease in the number of blood vessels, the bile duct surrounding the blood vessels and bile duct epithelial cell proliferation in the early postoperative portal area. Pathologic examinations showed that inflammation of the rat portal area was aggravated, and biliary epithelial cell injury was significantly worsened. CONCLUSION:A prolonged biliary warm ischemia time results in aggravated injury of the bile duct and the surrounding vascular plexus in rat autologous orthotopic liver transplantation.

Warm ischemia time and elevated serum uric acid are associated with metabolic syndrome after liver transplantation with donation after cardiac death

AIM To describe the prevalence of posttransplant metabolic syndrome(PTMS) after donation after cardiac death(DCD) liver transplantation(LT) and the pre-and postoperative risk factors.METHODS One hundred and forty-seven subjects who underwent DCD LT from January 2012 to February 2016 were enrolled in this study. The demographics and the clinical characteristics of pre-and post-transplantation were collected for both recipients and donors. PTMS was defined according to the 2004 Adult Treatment Panel-Ⅲ criteria. All subjects were followed monthly for the initial 6 mo after discharge, and then, every 3 mo for 2 years. The subjects were followed every 6 mo or as required after 2 years post-LT.RESULTS The prevalence of PTMS after DCD donor orthotopic LT was 20/147(13.6%). Recipient's body mass index(P = 0.024), warm ischemia time(WIT)(P = 0.045), and posttransplant hyperuricemia(P = 0.001) were significantly associated with PTMS. The change in serum uric acid levels in PTMS patients was significantly higher than that in non-PTMS patients(P < 0.001). After the 1 s t mo, the level of serum uric acid of PTMS patients rose continually over a period, while it was unaltered in non-PTMS patients. After transplantation, the level of serum uric acid in PTMS patients was not associated with renal function.CONCLUSION PTMS could occur at early stage after DCD LT with growing morbidity with the passage of time. WIT and post-LT hyperuricemia are associated with the prevalence of PTMS. An increased serum uric acid level is highly associated with PTMS and could act as a serum marker in this disease.

Establishment of a rat liver transplantation model with prolonged biliary warm ischemia time

AIM:To investigate the impact of different time points of secondary warm ischemia on bile duct in a rat autologous liver transplantation model with external bile drainage.METHODS:One hundred and thirty-six male inbred SD rats were randomly assigned to one of four groups(Ⅰ-Ⅳ) according to the secondary warm ischemia time of 0,10,20 and 40 min.A rat model of autologous liver transplantation with continuous external biliary drainage under ether anesthesia was established.Ten rats in each group were used to evaluate the one-week survival rate.At 6 h,24 h,3 d and 7 d after reperfusion of the hepatic artery,6 rats were killed in each group to collect the blood sample via the infrahepatic vena cava and the median lobe of liver for assay.Warm ischemia time of liver,cold perfusion time,anhepaticphase,operative duration for biliary external drainage and survival rates in the four groups were analyzed for the establishment of models.RESULTS:No significant difference was shown in warm ischemia time,anhepatic phase and operative duration for biliary external drainage among the four groups.Five of the 40 rats in this study evaluated for the one-week survival rate died,including three deaths of severe pulmonary infection in group Ⅳ.A significant decrease of one-week survival rate in group Ⅳ was noted compared with the other three groups.With the prolongation of the biliary warm ischemia time,the indexes of the liver function assessment were significantly elevated,and biliary epithelial cell apoptosis index also increased.Pathological examinations showed significantly aggravated inflammation in the portal area and bile duct epithelial cell injury with the prolonged secondary warm ischemia time.Microthrombi were found in the micrangium around the biliary tract in some sections from groups Ⅲ and Ⅳ.CONCLUSION:The relationship between secondary warm ischemia time and the bile duct injury degree is time-dependent,and 20 min of secondary warm ischemia time is feasible for the study of bile duct injury.

Dynamic microcirculatory changes in liver graft from non-heart-beating donor with warm ischemia injury in rat

BACKGROUND: Since the 1990s, liver grafts from non- heart-beating donor (NHBD) have become an alternative because of the deficiency of grafts from heart-beating-do- nors (HBDs). Warm ischemia injury, however, directly influences the grafts' activity and functional recovery after operation. We investigated the microcirculatory change of liver graft at different warm ischemia time (WIT) in rats and determined the maximum limitation of liver graft to warm ischemia. METHODS: According to WIT, 120 rats were divided ran- domly into 5 groups of 0, 15 , 30 , 45 , 60 minutes respec- tively. The microcirculatory changes of their liver grafts were measured including serum level of hyaluronic acid (HA) and ultrastructural changes. After orthotopic liver transplantation (OLT), the recovery of microcirculation of the liver grafts after 24 hours, 48 hours and 3 days was ob- served. RESULTS: Microcirculatory changes and function of the liver grafts became normal after reperfusion when the WIT was less than 30 minutes. In the 45-minute WI group, part of blood sinusoids was full of cytoplasmic blebs stemming from the microvilli of hepatocytes and hemocytes. The se- rum level of HA in each group after 45 minutes of WI re- covered after reperfusion. CONCLUSIONS: The microcirculatory change of rat liver graft is reversible when the WIT is less than 30 minutes: rat liver graft could be safely subject to warm ischemia within30 minutes. The maximal 45 minutes of WI can be tolera- ted by the microcirculatory function of liver graft. After 60 minutes of WI, irreversible disturbance of microcirculation may appear.

Energy metabolism and survival of liver grafts from non-heart-beating donor rats with warm ischemia injury

BACKGROUND: The shortage of donor livers is a critical limiting factor for the use of liver transplantation in treatment of end-stage liver diseases. Organs from non- heart-beating donors seem to be an effective option to alleviate this problem. Warm ischemia injury, however, directly influences the grafts' activity and functional recovery after operation. We investigated the energy metabolism and post-transplant survival of liver grafts after different warm ischemia times (WITs) in rats and determined the maximum limit for liver grafts with warm ischemia. METHODS: Rats were randomized into 7 groups with WITs of 0 (control), 10, 15, 20, 30, 45 or 60 minutes. The indices of energy metabolism were measured by reversed- phase high performance liquid chromatograpy and all liver graft specimens were subjected to ultrastructural observation. After orthotopic liver transplantation (OLT), the recovery of energy metabolism in liver grafts after 24 and 48 hours and the survival of the rats were assessed. RESULTS: The levels of adenosine triphosphate (ATP) and energy charge (EC) decreased gradually after different WITs in a time-dependent manner, and this was especially significant within 30 minutes. The levels of ATP and EC in liver grafts with 30 minutes of warm ischemia largely recovered 24 hours after OLT, with 45 minutes of warm ischemia partially recovered 48 hours after OLT, and with 60 minutes of warm ischemia, hardly recovered even 48 hours after OLT. The survival time after OLT did not significantly change with up to 30 minutes of WIT, while long-term survival was reduced with 45 and 60 minutes of WIT.CONCLUSIONS: The levels of ATP and EC after OLT may be important criteria for evaluating the quality of a liver graft. The WIT of a liver graft is closely related to the recovery of hepatic energy metabolism and the graft survival.

Can the rat donor liver tolerate prolonged warm ischemia?

The last two decades of the twentieth century have witnessed increasingly successful rates of liver transplantation. The number of liver transplantations has increased steadily while the number of organ donors has remained relatively constant. Thus a great disparity has developed between the demand and supply of donor organs and remains a major limiting factor for further expansion of liver transplantation. Although many procedures, such as split liver[1] , living-related transplantation[2] , and xenotransplantation[3], have been attempted clinically to overcome the shortage, it is hoped that livers harvested from non-heart-beating donors (NHBDs) would alleviatethe problem of organ shortage, which again becomes the focus of attention[4-9]. However, sensitivity of the liver to warm ischemia remains a major worry for use of theNHBDs. The aim of this animal study was to assess if murine liver could tolerate prolonged period of warm ischemia and to determine the optimum timing of intervention in the cadaver donor in order to preserve liver viability.

Cold ischemia time in liver transplantation:An overview

The standard approach to organ preservation in liver transplantation is by static cold storage and the time between the cross-clamping of a graft in a donor and its reperfusion in the recipient is defined as cold ischemia time(CIT).This simple definition reveals a multifactorial time frame that depends on donor hepatectomy time,transit time,and recipient surgery time,and is one of the most important donor-related risk factors which may influence the graft and recipient’s survival.Recently,the growing demand for the use of marginal liver grafts has prompted scientific exploration to analyze ischemia time factors and develop different organ preservation strategies.This review details the CIT definition and analyzes its different factors.It also explores the most recent strategies developed to implement each timestamp of CIT and to protect the graft from ischemic injury.

Assessment of Warm and Cold Ischemia on Functions of the Operated Kidney with ^99mTc-DMSA in Renal Masses: A Prospective and Randomized Study

Objective: To examine the effect of warm and cold ischemia on functions of the operated kidney in cases with a normal contralateral kidney undergoing nephron sparing surgery. Methods: This study enrolled 40 patients with a normal contralateral kidney and without a renal function threatening risk factor, who were operated with NSS. The patients were randomized at admission. They were divided into 2 equal groups as warm and cold ischemia. An ice application for 10 minutes was done to cold ischemia group after clamping renal artery. Renal functions were evaluated with Technesium-99m-Dimercaptosuccinic Acid (DMSA) and serum creatinine at the preoperative and postoperative (day 1, day 15, month 6, and month 12) period. Statistical analysis was done with Mann Whitney U test, Wilcoxon Signed Rank test, and Fredman test. A p value below 0.05 was considered statistically significant. Results: There were no significant differences between the groups in terms of age, body mass index, ischemia time, tumor size, amount of hemorrhage, and procedure time. Both groups had a significantly higher DMSA uptake at the preoperative period compared with the postoperative period (postoperative day 1, day 15, month 6, and month 12) (p 0.001). However, both groups had similar DMSA uptake results at the postoperative period. Preoperative and postoperative creatinine levels were not significantly different from each other in both groups. Conclusion: Based on tumor localization, nephron sparing surgery without use of superficial cooling appears as a viable option for small renal masses.

Donor hepatectomy time and liver transplantation outcomes: An opportunity that cannot be dismissed

The probability of developing primary dysfunction(PD)is a function of the probability of ischemia/reperfusion(I/R)injury.The probability of I/R injury in turn,is a function of several donor and transplantation process variables,among which is ischemia time.Custodio et al studied the duration of a special type of warm ischemia and showed,contrary to what is known,that a longer duration is not statistically different from a shorter one in PD development.This finding opens the door to the unforeseen opportunity of training fellows in performing hepatectomies,since the duration will not jeopardize liver transplant outcomes,albeit with some precautions.

Normothermic regional perfusion mobile teams in controlled donation after circulatory death pathway: Evidence and peculiarities

To facilitate the implementation of controlled donation after circulatory death(cDCD)programs even in hospitals not equipped with a local Extracorporeal Membrane Oxygenation(ECMO)team(Spokes),some countries and Italian Regions have launched a local cDCD network with a ECMO mobile team who move from Hub hospitals to Spokes for normothermic regional perfusion(NRP)implantation in the setting of a cDCD pathway.While ECMO teams have been clearly defined by the Extracorporeal Life Support Organization,regarding composition,responsibilities and training programs,no clear,widely accepted indications are to date available for NRP teams.Although existing NRP mobile networks were developed due to the urgent need to increase the number of cDCDs,there is now the necessity for transplantation medicine to identify the peculiarities and responsibility of a NRP team for all those centers launching a cDCD pathway.Thus,in the present manuscript we summarized the character-istics of an ECMO mobile team,highlighting similarities and differences with the NRP mobile team.We also assessed existing evidence on NRP teams with the goal of identifying the characteristic and essential features of an NRP mobile team for a cDCD program,especially for those centers who are starting the program.Differences were identified between the mobile ECMO team and NRP mobile team.The common essential feature for both mobile teams is high skills and experience to reduce complications and,in the case of cDCD,to reduce the total warm ischemic time.Dedicated training programs should be developed for the launch of de novo NRP teams.

基于3D Slicer软件的局限性肾癌供血动脉解剖分布研究

目的利用3D Slicer软件分析局限性肾癌供血动脉进入肿瘤的位置、数目与分布规律,为肾部分切除术中精准缝合提供解剖依据。方法收集2021年1月—2022年6月西安交通大学第二附属医院泌尿外科因肾癌行肾部分切除术的患者资料,将患者术前肾动脉计算机断层扫描(CT)血管成像资料以DICOM格式导入3D Slicer软件,从水平面、矢状面和冠状面对肿瘤-血管的相对位置进行重建,分析各平面中肿瘤供血动脉的数目及分布特点。结果共收集112例(男59例、女53例)肾癌患者相关资料,肿瘤均为单发,RENAL评分为4~10分,肿瘤分期T1a 58例、T1b 48例、T2a 6例。其中38例(33.93%)有1条肿瘤供血动脉、53例(47.32%)有2条肿瘤供血动脉、21例(18.75%)有3条肿瘤供血动脉。这207条肿瘤供血动脉中有22条(10.63%)经肿瘤-肾脏接触面(肿瘤床)浅部进入肿瘤,有185条(89.37%)经肿瘤床深部进入肿瘤。结论在局限性肾癌中,近90%的供血动脉由肿瘤床深部进入肿瘤,为肾部分切除术中精准肿瘤切除及创面缝合提供了解剖依据。

温针灸对后循环缺血眩晕大鼠神经递质和IKB/NF-κB信号通路的影响

目的:研究温针灸对后循环缺血眩晕大鼠神经递质和人核因子κB抑制蛋白(inhibitor of NF-κB,IKB)/核转录因子κB(nuclear factor-κB,NF-κB)信号通路的影响。方法:应用随机数字表法将70只SD大鼠随机分为温针灸组、假手术组、模型组、普通针刺组和药物组各14只。假手术组仅分离大鼠右侧颈总动脉(common carotid artery,CCA)及右侧锁骨下动脉(subclavian artery,SCA),不进行CCA及SCA结扎术,直接缝合,其余各组进行CCA及SCA结扎建立后循环缺血眩晕大鼠模型。假手术组及模型组不进行干预;药物组给予盐酸氯桂利嗪治疗;普通针刺组在药物组基础上于“风池“”率谷“”百会”穴进行普通针刺;温针灸组在药物组基础上于“风池“”率谷“”百会”穴进行温针灸。干预结束后,采用激光多普勒血流仪检测各组大鼠前庭神经核血流量下降率;应用TUNEL法检测各组大鼠前庭神经核细胞凋亡指数(apoptotic index,AI);蛋白免疫印迹(western blot,WB)法检测各组大鼠前庭神经核B淋巴细胞因子相关X蛋白(Bcl-2-associated X protein,Bax)、B淋巴细胞瘤2(B cell lymphama,Bcl-2)和含半胱氨酸的天冬氨酸蛋白水解酶3(cysteinyl aspartate specific proteinase 3,caspase-3)蛋白表达;检测各组大鼠脑组织IKB mRNA、NF-κB mRNA及IKB、NF-κB p65蛋白表达;酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测大鼠神经递质变化情况。结果:与模型组比较,药物组、温针灸组和普通针刺组大鼠治疗后右侧前庭神经血流下降率、前庭神经核AI均降低(P<0.05),温针灸组低于普通针刺组和药物组(P<0.05);与模型组比较,药物组、温针灸组和普通针刺组大鼠前庭神经核Bax和Caspase-3蛋白表达降低,Bcl-2蛋白表达升高(P<0.05),温针灸组Bax和Caspase-3蛋白表达低于药物组和普通针刺组(P<0.05),Bcl-2蛋白表达高于药物组和普通针刺组(P<0.05);与模型组比较,药物组、温针灸组和普通针刺组大鼠海马区与大脑皮质中乙酰胆碱酶、谷氨酸浓度降低,去甲肾上腺素、5-羟色胺、γ-氨基丁酸浓度升高(P<0.05),温针灸组乙酰胆碱酶、谷氨酸浓度低于普通针刺组和药物组(P<0.05),5-羟色胺、γ-氨基丁酸高于药物组和普通针刺组(P<0.05);与模型组比较,药物组、温针灸组和普通针刺组大鼠脑组织中IKB、NF-κBp65蛋白及mRNA表达降低(P<0.05),温针灸组低于普通针刺组和药物组(P<0.05)。结论:温针灸能够改善后循环缺血眩晕大鼠眩晕症状,降低神经细胞凋亡,调节神经递质紊乱,其作用机制可能与调控IKB/NF-κB信号通路有关。

右美托咪定对大鼠热/冷缺血后供肾的保护作用及机制研究

目的探索右美托咪定(Dex)对大鼠热缺血、冷缺血后供肾的保护作用及其潜在机制。方法将21只雄性SD大鼠随机分为对照组、模型组(0µmol/L Dex组)和Dex组(1µmol/L Dex组),每组7只。采用放血法处死大鼠,热缺血30 min后摘取肾,对照组供肾直接固定或-80℃保存,模型组和Dex组供肾分别置于含0µmol/L Dex和1µmol/L Dex的威斯康星大学器官保存液中4℃冷藏24 h,模拟供肾冷缺血状态。肾组织行HE染色后观察形态学变化并进行组织损伤评分,比色法测定N-乙酰-β-D-氨基葡萄糖苷酶(NAG)活力,TUNEL法检测细胞凋亡情况,Western blot检测受体相互作用蛋白激酶3(RIPK3)蛋白表达水平,免疫荧光法测定磷酸化混合谱系激酶结构域样假激酶(pMLKL)表达水平。结果对照组肾小球、肾小管无明显异常,模型组部分肾小管扩张,肾小管上皮细胞扁平,Dex组肾小管损伤较模型组缓解。与对照组比较,模型组和Dex组肾损伤评分、NAG活性升高,TUNEL阳性凋亡细胞数增多,pMLKL和RIPK3表达水平增加(P<0.05)。与模型组比较,Dex组肾损伤评分、NAG活性降低,TUNEL阳性凋亡细胞数减少,pMLKL表达水平下降(P<0.05)。结论Dex对大鼠热缺血、冷缺血后供肾具有保护作用,其机制与减少细胞凋亡、抑制坏死性凋亡有关。

腹腔镜供肝获取手术的发展与展望

近年来,得益于微创外科技术的进步,腹腔镜供肝获取手术(LLDH)得到了迅速的发展。从2002年该项技术首次报道以来,各大移植中心一直在不断探索发展和积累经验。相比于传统的开放手术,该项技术有着创伤小、术中出血少、术后并发症发生率低等优点。但同时,在热缺血时间管理、克服学习曲线、避免胆道并发症以及出血控制等方面存在着一定的难点,仍需更多的探索以解决这些问题。一些新技术和新方法的应用也使该项技术更加安全、高效。本文从LLDH的发展历程、手术难点和并发症、技术改进等三个方面进行讨论,并展望该项技术的未来前景和发展方向。

Protective effects of ischemic preconditioning and application of lipoic acid prior to 90 min of hepatic ischemia in a rat model

AIM： To compare different preconditioning strategies to protect the liver from ischemia/reperfusion injury focusing on the expression of pro- and anti-apoptotic proteins. Interventions comprised different modes of ischemic preconditioning （IP） as well as pharmacologic pretreatment by α-lipoic acid （LA）. METHODS： Several groups of rats were compared： sham operated animals, non-pretreated animals （nt）, animals receiving IP （10 rain of ischemia by clamping of the portal triad and 10 min of reperfusion） prior to sustained ischemia, animals receiving selective ischemic preconditioning （IPsel, 10 min of ischemia by selective clamping of the ischemic lobe and 10 rain of reperfusion） prior to sustained ichemia, and animals receiving 500 1μmol α-LA injected i.v. 15 min prior to the induction of 90 min of selective ischemia. RESULTS： Cellular damage was decreased only in the LA group. TUNEL-positive hepatocytes as well as necrotic hepatocyte injury were also decreased only by LA（19 ± 2 vs 10 ± 1, P〈 0.05 and 29 ± 5 vs 12 ± 1, P 〈 0.05）. Whereas caspase 3- activities in liver tissue were unchanged, caspase 9- activity in liver tissue was decreased only by LA pretreatment （3.1 ± 0.3 vs 1.8 ± 0.2, P 〈 0.05）. Survival rate as the endpoint of liver function was increased after IP and LA pretreatment but not after IPsel. Levels of lipid peroxidation （LPO） in liver tissue were decreased in the IP as well as in the LA group compared to the nt group. Determination of pro- and anti-apoptotic proteins showed a shift towards anti-apoptotic proteins by LA. In contrast, both our IP strategies failed to influence apototic cell death. CONCLUSION： IP, consisting of 10 min of ischemia and 10 min of reperfusion, ischemia/reperfusion injury protects only partly against of the liver prior to 90 min of selective ischemia. IPsel did not influence ischemic tolerance of the liver. LA improved tolerance to ischemia, possibly by downregulation of pro-apoptotic Bax.