大鼠不同体积肝移植术后门静脉血内毒素水平的动态变化

目的 比较大鼠不同体积肝移植术后门静脉血内毒素水平及其受体CDl4和Toll样受体4(TLR4)的变化以探讨肝移植小肝综合征的病因.方法 参照"Kamada二袖套法"和体内切肝法建立SD大鼠→SD大鼠原位100%(Ⅰ组)、50%(Ⅱ组)、30%(Ⅲ组)体积肝移植组和假手术组.于门静脉重新开放后1、3、6、12和24 h检测各组受鼠门静脉内毒素的水平以及肝组织CD14 mRNA和TLR4 mRNA的相对表达量.结果 Ⅰ、Ⅱ组术后门静脉血内毒素血症高峰出现在术后1 h,随后下降,Ⅰ组在术后3 h接近正常,Ⅱ组在术后12 h接近正常;Ⅲ组高峰出现在术后6 h,在术后24 h接近正常.Ⅰ、Ⅱ、Ⅲ组再灌注后CD14 mRNA、TLR4 mRNA相对表达量均明显增加,都在再灌注后3 h达到高峰,后渐下降,较假手术组显著升高(P＜0.01).结论 大鼠原位100%、50%、30%体积肝移植术后出现门静脉内毒素血症,供肝体积越小术后受者内毒素水平越高,持续时间越长,肝组织CD14 mRNA和TLR4 mRNA的相对表达量也越高,持续时间也越长.     

Effects of intrahepatic canine islet autotransplantation on the portal vein pressure and liver function

Currently, the most common method used for human islet transplantation is intrahepatic implantation via the portal vein, which may affect portal vein pressure and liver function. The aim of this study was to investigate the effects of intrahepatic canine islet autotransplantation on portal vein pressure and liver function. After total pancreatectomy was performed in 30 mongrel dogs, islets were isolated and transplanted back into the portal vein of the same dog. In our series, 12 dogs achieved normoglycemia (fasting glucose <200 mg/dL) without exogenous insulin after transplantation. The portal vein pressure increased from 4.6 +/- 1.5 to 7.7 +/- 2.9 cm H(2)O after islet infusion (P < .05). Alanine transferase amino transferase (ALT) levels gradually increased after pancreatectomy with the peak at 4 weeks after islet infusion. But the changes of portal vein pressure and ALT were not significantly different between successful and failed islet transplantation. In summary, elevation of portal vein pressure and liver enzymes were noted after intrahepatic canine islet autotransplantation. However, they did not influence the transplant outcome.     

The experimental study on the temporary portal vein arterialization in the canine liver transplantation: preliminary report

To evaluate the feasibility of temporary portal vein arterialization (PVA) in orthotopic partial liver transplantation (PLT), we performed 5 canine PLTs with PVA assessing the changes in arterial ketone body ratio (AKBR) as an index of hepatic energy status, and measuring portal pressure and flow. After anastomosis of hepatic vein, the graft liver was revascularized with arterial blood shunted from the external iliac artery to the hepatic side of the portal vein. By using this technique, both anhepatic period of the recipient and ischemic time, especially warm ischemic time, of the allograft were markedly shortened (31.0 +/- 4.5 min: Mean +/- SEM). Four out of 5 recipients survived for at least 5 days (13 days in average). The AKBR was restored immediately after PVA and showed almost the same values as those at preclamping and after completion of anastomoses of both portal vein and hepatic artery. No significant difference in portal venous pressure was observed between during PVA and after vascular reconstruction. Portal blood flow during PVA was about one fourth of the total hepatic blood flow at preclamping. These results suggest that PVA can be used as an alternative procedure in PLT.     

The role of TIPS for portal vein patency in liver transplant patients with portal vein thrombosis.

The purpose of this research was to study the efficacy and outcomes of transjugular intrahepatic shunt (TIPS) in end-stage liver disease (ESLD) patients with portal vein thrombosis (PVT) eligible for orthotopic liver transplant. Nine consecutive patients with PVT underwent TIPS as a nonemergent elective outpatient procedure. The primary indication for TIPS was to maintain portal vein patency for optimal surgical outcome. Eight patients underwent contrast enhanced computed tomography (CT) and 1 magnetic resonance imaging diagnosing PVT. Shunt creation was determined by available targets at the time of TIPS and by prior imaging. Patients were followed with portography, ultrasound, CT, or magnetic resonance imaging, and the luminal occlusion was estimated before and after TIPS. Primary endpoints were transplantation, removal from the transplant list, or death. Stabilization, improvement, or complete resolution of thrombosis was considered successful therapy. Failures included propagation of thrombosis or vessel occlusion, and poor surgical anatomy due to PVT. Of 9 patients with PVT, TIPS was successfully placed in all patients without complication or TIPS-related mortality. Eight of 9 patients (88.8%) had improvement at follow-up. One patient failed therapy and re-thrombosed. Two patients (22.2%) were transplanted without complication and had no PVT at the time of transplant. Eight of 9 patients were listed for transplant at the time of their TIPS. Eight of 9 PVTs were nonocclusive. Four of 9 patients (44%) had evidence of cavernous transformation. Two patients expired during follow-up 42 and 44 months after TIPS. Three patients remain on the transplant list. One patient has not been listed due to nonprogression of disease. One patient has been removed from the transplant list because of comorbid disease. In conclusion, TIPS is safe and effective in patients with PVT and ESLD requiring transplant. Patients can be successfully transplanted with optimal surgical anatomy.     

Reconstructing the portal vein through a posterior pancreatic tunnel: New choice for portal vein thrombosis during liver transplantation

BACKGROUNDThrombectomy and anatomical anastomosis (TAA) has long been considered the optimal approach to portal vein thrombosis (PVT) in liver transplantation (LT). However, TAA and the current approach for non-physiological portal reconstructions are associated with a higher rate of complications and mortality in some cases.AIMTo describe a new choice for reconstructing the portal vein through a posterior pancreatic tunnel (RPVPPT) to address cases of unresectable PVT.METHODSBetween August 2019 and August 2021, 245 adult LTs were performed. Forty-five (18.4%) patients were confirmed to have PVT before surgery, among which seven underwent PV reconstruction via the RPVPPT approach. We retrospectively analyzed the surgical procedure and postoperative complications of these seven recipients that underwent PV reconstruction due to PVT.RESULTSDuring the procedure, PVT was found in all the seven cases with significant adhesion to the vascular wall and could not be dissected. The portal vein proximal to the superior mesenteric vein was damaged in one case when attempting thrombolectomy, resulting in massive bleeding. LT was successfully performed in all patients with a mean duration of 585 min (range 491-756 min) and mean intraoperative blood loss of 800 mL (range 500-3000 mL). Postoperative complications consisted of chylous leakage (n = 3), insufficient portal venous flow to the graft (n = 1), intra-abdominal hemorrhage (n = 1), pulmonary infection (n = 1), and perioperative death (n = 1). The remaining six patients survived at 12-17 mo follow-up.CONCLUSIONThe RPVPPT technique might be a safe and effective surgical procedure during LT for complex PVT. However, follow-up studies with large samples are still warranted due to the relatively small number of cases.     

Hepatic artery vs. portal vein infusion of microbeads: a large animal pre‐clinical model evaluating the intrahepatic capacity for cell infusion and imaging

Wang W, Liu S, Zheng W, Gao F, Hawthorne WJ, Yi S. Hepatic artery vs. portal vein infusion of microbeads: a large animal pre‐clinical model evaluating the intrahepatic capacity for cell infusion and imaging. Xenotransplantation 2010; 17: 207–214. © 2010 John Wiley & Sons A/S. Abstract: Background: Islet xeno‐transplantation via the portal vein has been proposed as an alternative of islet allo‐transplantation for treatment of type 1 diabetes. However, the precise hepatic capacity has not been addressed. Methods: We mimicked cell transplantation by infusion of dogs with alginate/poly‐1‐lysine/alginate (APA) microbeads via either the portal vein (PV) or hepatic artery (HA). The maximal adaptable capacity for infused microbeads was evaluated by examination of vasculature, microvasculature, hepatic hemodynamics, portal vein, and hepatic artery pressures and liver function in the microbead recipient dogs. Results: PV but not HA dogs demonstrated elevated portal pressure during the infusion procedure in a dose‐dependent manner. Four out of twelve PV dogs infused with 32 000 microbeads/kg developed acute liver infarction within 24 h after infusion with four of the remaining eight animals developing portal venous thrombosis within 24 h following infusion. All PV animals demonstrated abnormal alanine aminotransferase (ALT) values, and the extent and duration of increased ALT levels correlated with the increase in the number of microbeads infused. In contrast, HA animals infused with as many as 32 000 microbeads/kg had neither portal thrombosis nor abnormal liver function. Conclusions: The capacity for intrahepatic cell infusion is finite and the intrahepatic artery may have a less hemodynamic interference impact on transplantation of cells into the liver when a larger volume of cells is required to achieve curable outcomes in both allo‐ and xeno‐transplantation.     

Preoperative portal vein embolization for major liver resection: a meta-analysis

INTRODUCTION: Preoperative portal vein embolization (PVE) is used clinically to prevent postoperative liver insufficiency. The current study examined the impact of portal vein embolization on liver resection. METHOD: A comprehensive Medline search to identify all registered literature in the English language on portal vein embolization. Meta-analysis was performed to assess the result of PVE and its impact on major liver resection. RESULT: A total of 75 publications met the search criteria but only 37 provided data sufficiently enough for analysis involving 1088 patients. The overall morbidity rate for PVE was 2.2% without mortality. Four weeks following PVE, 85% patients underwent the planned hepatectomy (n = 930). Twenty-three patients had transient liver failure following resection after PVE (2.5%) but 7 patients developed acute liver failure and died (0.8%).The reason for nonresection following PVE (n = 158, 15%) included inadequate hypertrophy of remnant liver (n = 18), severe progression of liver metastasis (n = 43), extrahepatic spread (n = 35), refusal to surgery (n = 1), poor general condition (n = 1), altered treatment to transcatheter artery embolization or chemotherapy (n = 24), complete remission after treatment with 3 cycles of fluoracil and interferon alpha in a patient with hepatocellular carcinoma (n = 1), incomplete pre- or postembolization scanning (n = 8). Of those who underwent laparotomy without resection, (n = 27) reasons included intraoperative finding of peritoneal dissemination (n = 15), portal node metastasis (n = 2), severe invasion of the tumor to the hepatic artery and portal vein (n = 1), and gross tumoral extension precluding curative resection (n = 9).Two techniques were used for portal vein embolization: percutaneous transhepatic portal embolization, (PTPE) and transileocolic portal embolization, (TIPE). The increase in remnant liver volume was much greater in PTPE than TIPE group (11.9% vs. 9.7%; P = 0.00001). However, the proportion of patients who underwent resection following PVE was 97% in TIPE and 88% PTPE, respectively (P = <0.00001). Although there was no significant difference in patients who had major complications post-PVE, the rate for minor complications was significantly higher among patients who had PTPE (53.6% vs. 0%, P = <0.0001). CONCLUSION: PVE is a safe and effective procedure in inducing liver hypertrophy to prevent postresection liver failure due to insufficient liver remnant.     

Intramucosal pH and liver endotoxin clearance during experimental liver transplantation

The study was designed to assess the gastrointestinal ischaemia and the influence of the specific Kupffer cell toxin gadolinium chloride (GdCl₃) on the hepatic and extrahepatic endotoxin [lipopolysaccharide (LPS)] clearance during experimental orthotopic liver transplantation (OLT) in pigs. In eight pig liver transplantations, the donors received 20 mg/kg of GdCl₃ 24 h before explantation, while controls (n = 8) received normal saline. Gastric and sigmoid intramucosal pH (pHi), LPS and endotoxin-neutralising capacity (ENC) levels were measured in the portal vein and superior vena cava after laparatomy, at the end of the anhepatic phase and 1 h after reperfusion. During the anhepatic phase, the sigmoid pHi decreased significantly from 7.32 ± 0.02 to 7.29 ± 0.03 (P < 0.001) and was associated with a substantial increase of portal LPS. Following reperfusion, the systemic LPS concentrations were significantly lower in the pretreated group [39 ± 23 pg/ml (Control); 14 ± 7 (GdCl₃); P < 0.05] suggesting an improved liver LPS clearance [86 % (GdCl₃); 58.2 % (Control); P < 0.05]. This corresponded to an increased ENC in the pretreated group [118 ± 52 ENU/ml (GdCl₃) vs 81 ± 45 ENU/ml (Control); P < 0.05]. The anhepatic phase induced splanchnic ischaemia which correlated with portal endotoxaemia. Donor preconditioning with GdCl₃ leads to lower systemic LPS concentrations in the recipient and increases ENC values in the early phase after OLT. An improved hepatocellular LPS extraction and/or an activation of the extrahepatic reticulo-endothelial system as a result of GdCl₃ treatment is discussed.     

Superior mesenteric vein inflow for liver transplantation when the portal vein is occluded

An alternative solution to the problem of liver transplantation in the patient with an occluded portal vein is described. It uses a bridge graft of donor iliac vein from the superior mesenteric vein at the base of the colonic mesentery. The graft is tunnelled over the pancreas and under the stomach to the region of the liver hilum to provide portal inflow. This procedure was employed successfully in four patients, with patency for more than 2 years in the patient with the longest follow-up. By this approach it is routinely possible to perform a transplant procedure in a recipient with an occluded portal vein.     

Ligation of a branch of the portal vein for carcinoma of the liver.

Portal branch ligation, a new surgical treatment for unresectable carcinoma of the liver, was performed in twenty patients. All the patients tolerated the procedure, and morbidity and mortality were minimal, even in patients in poor general condition. The responses to ligation differed considerably, but significant palliation was attained in some patients and one survived six years. The effect of portal branch ligation on the tumor appears to be closely related to the degree of tumor vascularity, tumor malignancy, and portal circulatory disturbances such as cirrhosis, portal hypertension, or portal thrombosis. We believe that the present procedure can be recommended for clinical application in some patients with unresectable carcinoma of the liver.     

Classification of portal vein anatomy for partial liver transplantation

The anatomy of the portal vein is usually classified as 3 to 5 patterns and simple compared with the anatomy of the hepatic artery. The variety of portal vein anatomy was examined in 287 living donors for liver transplantation. More than 90% of donors showed a normal bifurcation type; 6% showed the trifurcation type. Only 3% displayed a separate origin of the right paramedian and the right lateral branches. There was no anomalous pattern that had not been reported previously. In our series, we conclude that it is rare for 2 or more stumps of portal vein to appear in partial liver transplantation. The frequency is much less if the left liver or the right lateral liver graft is used for adult-to-adult living donor liver transplantation.     

Temporary portal vein arterialization as an attractive option in canine orthotopic partial liver transplantation.

We performed 22 canine orthotopic partial liver transplantations (PLTs) with three different revascularization methods; portal vein arterialization (PVA group, n = 11), hepatic arterial shunt (HAS group, n = 5), and conventional portal vein reperfusion (control group, n = 6). Our purpose was to evaluate the feasibility of PVA as a revascularization technique in PLT assessing the changes in arterial ketone body ratio (KBR) as an index of hepatic energy status. After the first anastomosis (left hepatic vein), the ischemic partial liver graft was revascularized with arterial blood flow shunted from the external iliac artery to the hepatic side of the portal vein (PVA group) or the proper hepatic artery (HAS group). Both anhepatic period and ischemia time were significantly shortened in groups PVA and HAS as compared with those in control. In the PVA group, 10 out of 11 recipients survived for at least 5 days (14.2 +/- 3.8 days, mean +/- SEM), while 3 out of 5 (5.2 +/- 1.0) survived in the HAS group and 4 out of 6 (6.2 +/- 1.3) in the controls. Although portal blood flow during PVA was only about 25% of the total hepatic blood flow at preclamping, the KBR was rapidly restored after PVA and showed almost the same values at preclamping. The KBR values during the arterialization time and initial velocity of KBR recovery in the PVA group were significantly higher than those in the HAS and control groups. These results suggest that PVA presents an attractive option in PLT.     

门静脉血栓对终末期肝硬化病人行肝移植手术的影响

目的探讨合并门静脉血栓(portal vein thrombosis,PVT)的终末期肝硬化病人行肝移植手术的处理方法及其疗效。方法回顾性分析2010年1月至2015年12月在中山大学附属第一医院器官移植中心接受肝移植手术的152例终末期肝硬化病人的临床资料。32例合并PVT的病人作为PVT组,其中Ⅰ级10例、Ⅱ级13例、Ⅲ级8例、Ⅳ级1例。其余120例无PVT的病人作为对照组。结果PV/T组术前脾切除史的比例明显高于对照组(46.8%比18.3%,P0.05),差异有统计学意义。PVT组较对照组明显延长无肝期时间[(72.5±25.3)min比(57.6±18.4)min,P0.05]和总手术时间[(622.4±183.5)min比(503.2±123.6)min],差异均有统计学意义。2组病人在术中出血量、ICU住院时间、术后并发症发生率、围手术期病死率、1年及3年生存率的比较上差异均无统计学意义(P0.05)。PVT组术后再栓塞率高于对照组(9.4%比1.7%,P0.05)。结论门静脉血栓一定程度上增加了终末期肝硬化病人肝移植手术的难度,Ⅰ~Ⅲ级PVT不影响病人的预后,仍可通过肝移植手术取得良好的疗效。Ⅳ级PVT肝移植手术的难度和风险会明显增加,应谨慎对待。     

门静脉重建技术在肝切除术中的应用

门静脉重建技术是复杂肝脏外科手术的必备技术.结合精准肝切除技术可使复杂肝胆肿瘤治疗达到手术切缘无残留或肉眼无残留,从而有效提高患者存活时间及生存质量.该技术要求对肝脏入肝血管解剖及胆道解剖极其熟悉.同时,还需术前精确评估影像学资料,制定手术预案,充分利用团队力量,合理运用术中超声、冷冻复苏血管技术、血管成型技术,以达到最佳治疗效果.