Intraoperative hepatic artery blood flow predicts early hepatic artery thrombosis after liver transplantation

Hepatic artery complications after orthotopic liver transplantation are associated with a high rate of graft loss and mortality (23% to 35%) because they can lead to liver ischemia. The reported incidence of hepatic artery thrombosis (HAT) after adult liver transplantation is 2.5% to 6.8%. Typically, these patients are treated with urgent surgical revascularization or emergent liver retransplantation. Since January 2007, we have recorded the postanastomotic hepatic artery flow after revascularization. The aim of this study was to assess the relationship between hepatic blood flow on revascularization and early HAT. Retrospectively, we reviewed perioperative variables from 110 consecutive liver transplantation performed at the Virgen del Rocío University Hospital (Seville, Spain) between January 2007 and October 2010. We evaluated the following preoperative (donor and recipient) and intraoperative variables: donor and recipient age, cytomegalovirus serology, ABO-compatibility, anatomical variations of the donor hepatic artery, number of arterial anastomoses, portal and hepatic artery flow before closure, cold ischemia time, and blood transfusion. These variables were included in a univariate analysis. Of the 110 patients included in the study, 85 (77.7%) were male. The median age was 52 years. ABO blood groups were identical between donor and recipient in all the patients. The prevalence of early HAT was 6.36% (7 of 110). Crude mortality with/without HAT was 22% versus 2% (P = .001), respectively. Crude graft loss rate with/without HAT was 27% versus 4% (P = .003), respectively. Early HAT was shown to be primarily associated with intraoperative hepatic artery blood flow (93.3 mL/min recipients with HAT versus 187.7 mL/min recipients without HAT, P < .0001). No retransplantation showed early HAT. In our experience, intraoperative hepatic artery blood flow predicts early HAT after liver transplantation.     

Routine Doppler ultrasound for the detection of clinically unsuspected vascular complications in the early postoperative phase after orthotopic liver transplantation

To assess the role of routine Doppler ultrasound in the detection of clinically unsuspected vascular complications in the early postoperative phase after orthotopic liver transplantation (OLT), the findings of 858 routinely performed Doppler ultrasound examinations were analyzed in 268 transplants. At various time intervals after OLT, we encountered 46 abnormal Doppler findings: hepatic artery (thrombosis), portal vein [anastomotic stenosis, (non)occlusive thrombosis or reversed flow], inferior vena cava [anastomotic stenosis with reversed flow, no flow, or (non)occlusive thrombosis], and hepatic veins (to-and-fro flow or stenosis with reversed flow) in 14, 20, 9, and 2 transplants, respectively. Most of these abnormal Doppler findings were confirmed by angiography, cavography, or surgery. The positive predictive value for hepatic artery thrombosis (HAT) was 12 out of 14, or 86 %. In the first 2 weeks after OLT, routine Doppler ultrasound revealed 20 of the 46 abnormal findings (43 %). Clinically unsuspected complications of the hepatic artery, portal vein, inferior vena cava, and hepatic veins were found in 9 of the 14 (64 %), 6 of the 20 (30 %), 3 of the 9 (33 %), and 2 of the 2 (100 %) transplants, respectively. The highest incidence – nine vascular complications – was found on the 1st day. On each of the remaining days (except for the 2nd and 9th days), one or two vascular complications were detected. HAT was found mainly in the 1st week. Vascular complications developed independently or concomitantly. We conclude that routine Doppler ultrasound is very important for the detection of clinically unsuspected vascular complications, particularly HAT, in the first 2 weeks after OLT. We recommend routine Doppler ultrasound of all hepatic vessels every 3 days in the early postoperative phase after OLT. Special attention should be paid to the 1st day. Received: 29 August 1997 Revised after revision: 10 February 1998 Accepted: 2 March 1998     

原位肝移植术中肝动脉变异及术后肝动脉血栓形成的处理

目的探讨肝移植术中肝动脉变异及术后肝动脉血栓形成的处理。方法统计2000年8月至2002年12月期间进行肝移植术的67例次供、受者肝动脉的变异情况；分析肝动脉的重建方式，探讨肝动脉变异与手术后肝动脉血栓形成的关系、肝动脉血栓形成的危险因素及肝动脉血栓形成后的处理。结果67例次供者肝脏和65例受者肝脏共出现肝动脉变异12例次，发生频率最高的为右肝动脉起源于肠系膜上动脉(5例)及左肝动脉起源于胃左动脉(3例)。肝动脉的重建方式如下：供者及受者肝总动脉与胃十二指肠动脉分叉处成型后吻合58例；腹主动脉与肝动脉搭桥2例；利用变异的肝动脉分支吻合7例。手术后发生肝动脉血栓形成3例，均经腹股沟处股动脉插管行肝动脉溶栓治疗，此3例患者中死亡1例。结论避免变异的肝动脉损伤、选择适当的肝动脉吻合方式可以保证移植肝脏的动脉血供。肝动脉血栓形成与肝动脉变异无关。作为肝动脉血栓形成后的保守治疗方法，肝动脉内溶栓治疗有可能避免2次移植。     

原位肝移植肝动脉重建临床分析

目的 总结分析原位肝移植肝动脉重建经验,提高肝移植疗效和受体存活率.方法 总结1995年5月至2006年12月实施的183例肝移植临床资料,常规动脉重建163例,供者腹腔动脉干Carrell's袖片或肝总动脉-脾动脉汇合部与受者肝左-右动脉汇合部吻合25例,胃十二指肠-肝固有动脉汇合部吻合134例,腹腔动脉干吻合4例.采用髂动脉.腹主动脉搭桥20例.术后根据凝血酶原时间(PT),应用普通肝素或低分子肝素抗凝.术中、术后应用多普勒超声监测肝动脉血供.结果 183例肝移植患者中有6例发生肝动脉并发症,发生率为3.28%(6/183),其中肝动脉血栓形成(hepatic artery thrombosis,HAT)5例,肝动脉狭窄(hepatic artery stenosis,HAS)1例.常规通路动脉重建组动脉并发症发生率1.84%(3/163),髂动脉-腹主动脉搭桥组为15.0%(3/20),两者比较差异有统计学意义(X2=9.73,P＜0.01).6例并发症患者中有1例HAT于术后19 d死于多器官功能衰竭,另5例通过介入治疗治愈,死亡率16.7%.结论 正确地选择肝动脉重建吻合的部位和术后有效的抗凝治疗减少HAT和HAS的发生,多普勒超声的早期发现和放射介入的及时治疗可以挽救移植物,避免再移植.     

Correlation between intraoperative blood flows and hepatic artery strictures in liver transplantation

Hepatic artery strictures (HASs) may be a source of morbidity and mortality in liver transplant recipients. This study evaluated the potential correlation between intraoperative arterial and venous blood flows measured after implantation of the liver allograft and the occurrence of postoperative HASs requiring repair. Prospectively collected data from 1,038 patients with complete data sets who underwent initial orthotopic liver transplantations between December 1984 and December 1999 were used. Electromagnetic flow measurements were routinely obtained in these cases. Hepatic artery and portal vein patency were reassessed routinely according to our protocol in the first postoperative day by Doppler ultrasound. When considered hemodynamically significant, strictures were corrected. There was a 6.2% incidence (n = 64) of hepatic artery stenosis in our transplant population. When considered as a whole, the hepatic artery stenosis group had lower intraoperative flow volumes than transplant recipients who did not develop strictures (mean flows, 452 v 518 mL/min, respectively; P = .025). The hepatic artery stenosis group also had lower intraoperative portal vein flows compared with the group without hepatic artery stenosis (1.80 v 2.11 L/min, respectively; P = .0043). Strictures were less frequent among transplant recipients with cryptogenic cirrhosis. We did not observe differences among the groups for retransplantation or patient and graft survival. In our series, there was a 6.2% incidence of postoperative HASs. We observed a significant association between intraoperative hepatic artery and portal vein flows and postoperative HASs. (Liver Transpl 2002;8:160-163.)     

Arterial conduits for hepatic artery revascularisation in adult liver transplantation

Arterial complications after orthotopic liver transplantation (OLT), including hepatic artery thrombosis (HAT), are important causes of early graft failure. The use of an arterial conduit is an accepted alternative to the utilisation of native recipient hepatic artery for specific indications. This study aims to determine the efficacy of arterial conduits and the outcome in OLT. We retrospectively reviewed 1,575 cadaveric adult OLTs and identified those in which an arterial conduit was used for hepatic revascularisation. Data on the primary disease, indication for using arterial conduit, type of vascular graft, operative technique and outcome were obtained. Thirty-six (2.3%) patients underwent OLT in which arterial conduits were used for hepatic artery (HA) revascularisation. Six of these were performed on the primary transplant, while the rest (n=30) were performed in patients undergoing re-transplantation, including six who had developed hepatic artery aneurysms. The incidence of arterial conduits was 0.4% (6/1,426 cases) in all primary OLTs and 20.1% (30/149 cases) in all re-transplants. Twenty-nine procedures utilised iliac artery grafts from the same donor as the liver, six used iliac artery grafts from a different donor, and a single patient underwent a polytetrafluoroethylene (PTFE) graft. Two techniques were used: infra-renal aorto-hepatic artery conduit and interposition between the donor and recipient native HAs, or branches of the HAs. The 30-day mortality rate for operations using an arterial conduit was 30.6%. Three conduits thrombosed at 9, 25 and 155 months, respectively, but one liver graft survived without re-transplantation. The arterial conduits had 1- and 5-year patency rates of 88.5% and 80.8%. The 1- and 5-year patient survival rates were 66.7% and 44%. We can thus conclude that an arterial conduit is a viable alternative option for hepatic revascularisation in both primary and re-transplantation. Despite a lower patency rate than that of native HA in the primary OLT group, the outcomes of arterial conduit patency and patient survival rates are both acceptable at 1 and 5 years, especially in the much larger re-OLT group.     

肝移植术中超声检查对肝动脉并发症的应用价值

目的　探讨肝移植术中超声 (IOUS)对肝动脉并发症的应用价值。方法　对 2 6例肝移植受者施行IOUS检查 ,以峰值速度 (HAV) >4 0cm/s和阻力指数 (RI) >0 5为正常肝动脉的标准。结果　共施行 2 7例次IOUS检查 ,其中检查阳性 (HAV <4 0cm/s或RI <0 5 ) 7例次 ,经 0 5 %普鲁卡因浸泡 ,解除血管痉挛或再次吻合后 ,仍未能达到上述标准的 3例中术后出现HAT和HAS各 1例 ,其余病人术后均未出现肝动脉并发症。IOUS对动脉并发症诊断的敏感度、特异度、阳性预测价值和阴性预测价值分别为 10 0 % (2 / 2 )、96 % (2 4 / 2 5 )、6 6 7% (2 / 3)和 10 0 % (2 4 / 2 4 )。结论　IOUS对肝动脉并发症较高的诊断价值 ,吻合后肝动脉RI应大于 0 5 ,HAV应大于 4 0cm/s ,对于RI <0 5 ,HAV<4 0cm/s的病例在排除动脉扭曲成角和解除血管痉挛后仍不能达到上述标准者应重新吻合肝动脉。     

Intraoperative flow measurement of native liver and allograft during orthotopic liver transplantation in children

Hepatic hemodynamic changes during liver transplantation (OLT) in children have not yet been studied. We measured intraoperative portal vein flow (PVF) and hepatic arterial flow (HAF) (mL/min) in 53 children and 58 grafts during OLT. Flows were measured in the native organ and in the allograft. In the native liver, PVF and HAF are similar; after transplantation they return to the physiological situation. No flow differences were seen between whole and partial grafts. Among the 8 (14%) portal vein thromboses, PVF was lower in both the native liver and the graft than in the no thrombosis group (P < .05). PVF <5 mL/min/kg was a risk factor to develop PV thrombosis. No graft loss occurred in 3 cases without PVF at the time of OLTs despite the observation that repermeabilization was not possible. In 4 patients with PVF <5 mL/min/kg, after tying a spontaneous spleno-renal shunt (n = 3) or performing a porto-renal vein anastomosis (n = 1), PVF reached >20 mL/min/kg, avoiding thrombosis. In conclusion, PVF and HAF measurements during pediatric OLT may predict patients at high risk for development of PV thrombosis.     

原位肝移植肝动脉并发症的预防和治疗

目的 总结分析原位肝移植肝动脉重建及其并发症的防治经验,提高肝移植疗效和受体存活率。方法 总结1995年5月至2005年4月实施的122例肝移植临床资料,肝动脉重建采用供者腹腔动脉干Carrell’s袖片或肝总动脉-脾动脉汇合部与受者肝左-右动脉汇合部袖片吻合21（16．76％）,与受者胃十二指肠-肝固有动脉汇合部吻合87例（71．76％）,采用髂动脉-腹主动脉搭桥14例（11．48％）。术后根据凝血酶原时间（PT）,应用普通肝素或低分子肝素预防性抗凝。术中、术后应用多普勒超声监测肝动脉血供。结果 术后肝动脉血栓形成（HAT）3例,肝动脉狭窄（HAS）2例。1例HAT于术后19d死于多器官功能衰竭,另4例通过放射介入治疗治愈。其余病例随访2～62个月,未见肝动脉血栓形成（HAT）和肝动脉狭窄（HAS）。本组肝动脉并发症发生率为4．10％。结论 正确地选择肝动脉重建吻合的部位和术后有效的抗凝治疗可减少HAT和HAS的发生,多普勒超声监测能早期发现HAT和HAS,挽救移植物,避免再移植。     

Liver Transplantation Using University of Wisconsin or Celsior Preserving Solutions in the Portal Vein and Euro-Collins in the Aorta

Introduction

Orthotopic liver transplantation (OLT) is today the gold standard treatment of the end-stage liver disease. Different solutions are used for graft preservation. Our objective was to compare the results of cadaveric donor OLT, preserved with the University of Wisconsin (UW) or Celsior solutions in the portal vein and Euro-Collins in the aorta.

Methods

We evaluated retrospectively 72 OLT recipients, including 36 with UW solution (group UW) and 36 with Celsior (group CS). Donors were perfused in situ with 1000 mL UW or Celsior in the portal vein of and 3000 mL of Euro-Collins in the aortia and on the back table managed with 500 mL UW or Celsior in the portal vein, 250 mL in the hepatic artery, and 250 mL in the biliary duct. We evaluated the following variables: donor characteristics, recipient features, intraoperative details, reperfusion injury, and steatosis via a biopsy after reperfusion. We noted grafts with primary nonfunction (PNF), initial poor function (IPF), rejection episodes, biliary duct complications, hepatic artery complications, re-OLT, and recipient death in the first year after OLT.

Results

The average age was 33.6 years in the UW group versus 41 years in the CS group (P = .048). There was a longer duration of surgery in the UW group (P = .001). The other recipient characteristics, ischemia-reperfusion injury, steatosis, PNF, IPF, rejection, re-OLT, and recipient survival were not different. Stenosis of the biliary duct occured in 3 (8.3%) cases in the UW group and 8 (22.2%) in the CS (P = .19) with hepatic artery thrombosis in 4 (11.1%) CS versus none in the UW group (P = .11).

Conclusion

Cadaveric donor OLT showed similar results with organs preserved with UW or Celsior in the portal vein and Euro-Collins in the aorta.     

Portal Vein Arterialization for Hepatic Artery Thrombosis in Liver Transplantation: A Case Report, Doppler-Ultrasound Aspects, and Review of the Literature

Portal vein arterialization (PVA) is a salvage procedure for insufficient hepatic arterial or portal vascularization. It plays a role in auxiliary and orthotopic liver transplantation (OLT). In OLT, current indications for PVA include hepatic artery thrombosis (HAT), pre-OLT or post-OLT extended splanchnic vein thrombosis, intraoperative low portal flow, and anatomic variations like the absence of portal and mesenteric veins. Out of the transplantation domain, PVA is used both in extensive surgery for malignancies of the liver, biliary tract, and pancreas and in the treatment of fulminant hepatic failure (FHF) due to intoxications. We describe a case of acute post-OLT HAT successfully treated with PVA as a short bridge to retransplantation. By Doppler ultrasound of clinical PVA we detected an increased intrahepatic portal flow velocity, with disappearance of the arterial spikes, a finding that needs further investigation. PVA represents a rare surgical procedure. In fact, it has been used most of all in urgent conditions or in case of abrupt vascular complications during surgery. According to the literature, PVA emerges as a salvage procedure for poor arterial or portal hepatic flow, both in OLT and in general abdominal surgery. The outcome of this procedure is unpredictable. The aim of the shunt is to gain time, awaiting the onset of collateral arterial vessels or the performance of definitive surgery. Its early thrombosis may be a catastrophic event, due to acute liver ischemia. In contrast, a late occlusion is often well tolerated. Strict surveillance is always useful because sometimes it is mandatory to embolize the arterioportal fistula to treat or to prevent the onset of portal hypertension.     

Diagnosis and treatment of hepatic artery thrombosis after liver transplantation

The aim of this study was to examine the clinical presentation and time of hepatic artery thrombosis (HAT) after orthotopic liver transplantation (OLT), stressing the role of imaging modalities. Therapeutic options are described, such as retransplantation (Re-OLT), hepatic resections and revascularization procedures, focusing on complications and outcome in a consecutive series of 687 OLT. Over the period from 1986 to 1999, 687 OLT were carried out in 601 patients, 592 of whom were adults and 95 pediatric subjects. Of these operations 601 were primary OLT and 86 Re-OLT (71 I Re-OLT, 14 II Re-OLT and 1 III Re-OLT). In this retrospective study, we reviewed rejection episodes, time of HAT (early or late), possible cause of HAT, day of suspected diagnosis of HAT and day of confirmation of diagnosis. Clinical presentation, management, complications, outcome, survival rates and the need for Re-OLT were also recorded. The incidence of HAT was 2.47% (17/687). Early HAT (n = 9, < 30 days) was diagnosed 15.6 days after OLT (range: 3-25 days), whereas late HAT (n = 8, > 30 days) occurred 295.1 days after OLT (range: 38-1830 days). In two asymptomatic patients (2/17: 11.7%), HAT was discovered incidentally. Most of the patients (11/17: 64.7%) presented with increased liver function test values and fever. Relapsing bacteremia occurred in 7/17 cases (41.1%), whereas a biliary stricture and biliary leak were diagnosed in 3/17 (17.6%) and in 1/17 patients (5.8%), respectively. Fulminant hepatic failure was the clinical presentation in 2/17 cases (11.7%). In one case the clinical presentation was acute and chronic rejection (1/17: 5.8%). Intrahepatic abscesses were diagnosed in one case (1/17: 5.8%), as well as an intrahepatic haemorrhage (1/17: 5.8%). Doppler ultrasound (DUS) correctly revealed HAT in 9 of the 17 patients (52.9% sensitivity). In 8 of the 9 patients (88.8%) in whom HAT was diagnosed by DUS, angiography was also performed to confirm the diagnosis. Overall, angiography detected HAT in 14/17 patients (82.3% sensitivity). HAT management consisted of immediate Re-OLT in 6 patients 6.8 days (range: 3-12 days) after diagnosis. Delayed Re-OLT was performed in 6 patients 529.1 days (range: 68-1920 days) after diagnosis. The overall retransplantation rate was 70.5% (12/17). Two patients died despite undergoing intraarterial urokinase treatment. Three grafts were salvaged, but suffered biliary stricture due to ischemic cholangitis and underwent hepatico-jejunostomy. A II Re-OLT was carried out in 4 of 12 patients (33.3%). The overall mortality rate was 41.1% (7/17). One-year and 3-year overall survival rates were 58.8% (10/17) and 47.0% (8/17), respectively. Both 5- and 10-year overall survival rates were 11.7% (2/17). Although the results of OLT have improved dramatically over the past few years, HAT is still associated with substantial morbidity, a high incidence of graft failure and high mortality rates. The use of DUS to screen for HAT has permitted earlier diagnosis, but early angiographic evaluation of the hepatic arteries is still needed for accurate diagnosis of HAT and remains the gold standard. Retransplantation is the definitive solution for HAT in the majority of cases, though it is essentially the patient's clinical condition that dictates the form of management.     

原位肝移植肝动脉血栓形成的预防和治疗

目的 总结原位肝移植肝动脉重建及其并发症的防治经验，以提高肝移植疗效和受体存活率。方法 分析9年间实施的85例原位肝移植患者的临床资料。肝动脉重建采用供者腹腔动脉干Carrell’s袖片或肝总动脉-脾动脉汇合部与受者肝左-右动脉部吻合16例(18．82％)，与受者胃十二指肠-肝固有动脉汇合部吻合61例(71．76％)，采用髂动脉-腹主动脉搭桥8例(9．42％)。术后根据凝血酶原时间(PT)，使用普通肝素或低分子肝素预防性抗凝。术中、术后应用多普勒超声监测肝动脉血供。结果 1例术中发生肝动脉血栓形成(HAT)，立即行血栓切除，重新吻合动脉，现已随访13个月，肝动脉保持通畅。其余84例随访2～54个月，未见HAT发生。全组HAT发生率为1．2％。结论 正确选择肝动脉重建吻合的部位和术后有效的抗凝治疗可以减少HAT的发生；多普勒超声监测能早期发现HAT，挽救移植物，避免再移植。     

Early Modulation of Portal Graft Inflow in Adult Living Donor Liver Transplant Recipients With High Portal Inflow Detected by Intraoperative Color Doppler Ultrasound

Splenic flow clearly contributes to portal hyperperfusion in end-stage liver disease patients with hypersplenism. Early modulation of portal graft inflow can relieve the partial graft from the deleterious effects of this portal overflow. Color Doppler ultrasound may play an important role in the intraoperative detection of patients with high recipient portal inflow. Among 138 cases, portal inflow increased after liver transplantation, namely recipient portal inflow (rPVF) of 60 to 554 mL/min/100 g graft weight (mean = 156 mL/min/100 g). There were eight cases in which the rPVF was >250 mL/min/100 g graft weight. In the early period of this study, there were two patients with high portal inflow (rPVF > 250 mL/min/100 g graft) who did not undergo modulation of the portal flow. Small-for-size syndrome occurred in two patients. Later in the series, six patients underwent intraoperative splenic arterial ligation or splenectomy; only one of them displayed prolonged hyperbilirubinemia. The incidence of small-for-size syndrome between these two groups was significant (P = .048). No complication occurred related to the splenic artery ligation or the splenectomy. In conclusion, early modulation of portal graft inflow can protect the graft from portal overflow damage. Intraoperative Doppler ultrasound measurement is an optimal modality for detection of high rPVF.     

Intraoperative blood flow measurements and liver allograft function: preliminary results

INTRODUCTION: Our previous studies showed a correlation of intraoperative renal allograft blood flow and immediate functions. A similar relation is not well established for liver transplantation. The aim of this study was to assess the relation between hepatic blood flow on revascularization and immediate liver graft function (IF). METHODS: Studies evaluating arterial and portal flow in newly transplanted livers were started in May 2004. Total hepatic artery and portal vein blood flow were assessed in 15 liver transplant recipients. Parenchymal flow was also recorded. Measurements were taken at 30 and 120 minutes after simultaneous arterial/portal reperfusion. Flow results were correlated with IF. RESULTS: Mean arterial blood flow (ABF) was 16.3 mL/min/100 g in both measurements. Portal flow was reduced from 168 to 127 mL/min/100 g from the first to the second measurement. Mean parenchymal flow (PF) did not alter over time (29.1 and 30.4 mL/min/100 g, respectively). Among recorded flow results we observed a significant correlation between PF with IF measured as: bile volume (R = 0.36 to 0.62; P < .05), serum AST (R = -0.4 to -0.68; P < .05), and ALT level (R = -0.2 to -0.71; P < .05), bilirubin level as well as INR (R = -0.39 to -0.61; P < .05) assayed daily for 14 days. Similar observations were made between ABF and INR, hiatal parenchymal flow, and ALT as well as INR. CONCLUSIONS: These preliminary results suggest hepatic blood flow may be a reliable predictor of graft viability and function. Of the variables measured, portal blood flow seems to be the most valuable indicator of liver function.     

Outcome of extra-anatomic vascular reconstruction in orthotopic liver transplantation

BACKGROUND: Portal venous and hepatic arterial reconstruction are critical to successful outcomes in orthotopic liver transplantation (OLT). With portal vein thrombosis or inadequate hepatic arterial inflow, extra-anatomic vascular reconstruction is required. However, the clinical outcomes following extra-anatomic vascular reconstruction are largely unknown. METHODS: To determine the outcomes associated with extra-anatomic vascular reconstruction, we performed a retrospective review of 205 OLT recipients transplanted between 1995 and 2000. RESULTS: Extra-anatomic portal venous inflow was based upon the recipient superior mesenteric vein using donor iliac vein graft in a retrogastric position (n = 12). Extra-anatomic arterial inflow was based on recipient infrarenal aorta using donor iliac artery graft through the transverse mesocolon (n = 25). OLT with routine anatomic vascular construction served as control (n = 168). Extra-anatomic vascular reconstruction was not associated with increased morbidity, mortality, operating room time, length of stay, or thrombosis. CONCLUSION: We conclude that extra-anatomic vascular conduits are associated with excellent long-term outcomes and provide acceptable alternatives for vascular reconstruction in OLT.     

Transit time flow measurement in on-pump and off-pump coronary artery surgery

OBJECTIVE: Transit time flow measurement is frequently used during coronary artery bypass with and without cardiopulmonary bypass to detect graft dysfunction resulting from technical errors. METHODS: Intraoperative transit time flow measurement measurements of 896 patients requiring surgery for double- or triple-vessel disease were reviewed retrospectively. Six-hundred and ninety-five patients were operated on-pump (Group A: coronary artery bypass with cardiopulmonary bypass), and 201 patients off-pump (Group B: coronary artery bypass without cardiopulmonary bypass). Transit time flow measurement measurements were analyzed for mean flow (mL/min). In total, measurements of 2247 grafts were analyzed. RESULTS: Transit time flow measurement flows were lower in coronary artery bypass without cardiopulmonary bypass patients (left internal thoracic artery to left anterior descending artery: Group A, 37 [31, 40] mL/min vs Group B, 24 [20, 26] mL/min; saphenous vein graft to left anterior descending artery: Group A, 46.5 [40, 56] mL/min vs Group B, 21 [14, 57] mL/min. Troponin I release was reduced in the coronary artery bypass without cardiopulmonary bypass patients, with median values of 7.8 [7.0, 8.3] microg/L in Group A and 1.2 [0.9, 2.3] microg/L in Group B. CONCLUSION: Evaluation of transit time flow measurement is valuable in determining coronary graft patency after coronary artery bypass with cardiopulmonary bypass and coronary artery bypass without cardiopulmonary bypass. Decreased troponin I release suggests a myocardial benefit of coronary artery bypass without cardiopulmonary bypass compared to coronary artery bypass with cardiopulmonary bypass, although the intraoperative transit time flow measurement flow measurements are markedly lower.     

Intraoperative hemodynamics in liver transplantation comparing orthotopic with heterotopic transplantation in the pig

The intraoperative hemodynamic changes and several graft function parameters were studied comparing orthotopic liver transplantation with auxiliary partial liver transplantation (APLT) in the pig. Thirty-one Yorkshire pigs (ca. 25 kg b.w.) were randomly allocated to OLT (n = 16) or APLT (n = 15). During the construction of portal anastomosis the median cardiac output dropped to 67% of the initial value in OLT and to 49% in APLT (P less than 0.02). Median duration of the portal flow interruption was shorter in APLT: 15 min versus 48 min in OLT (P less than 0.002). After unclamping of the aorta, the median systolic blood pressure dropped to 75 mmHg in OLT and to 90 mmHg in APLT (P less than 0.02). APLT is less time-consuming: median duration of transplantation was 128 min versus 165 min in OLT (P less than 0.002). SGOT levels were lower in APLT than in OLT (median SGOT on the first postoperative day 67 was IU/L versus 177 IU/L, P less than 0.002). It is concluded that APLT is a shorter procedure than OLT with a shorter portal flow interruption, being less offensive to the recipient.     

Pre‐operative trans‐catheter arterial chemo‐embolization increases hepatic artery thrombosis after liver transplantation – a retrospective study

Little is known about nonsurgical risk factors for hepatic artery thrombosis (HAT ) after liver transplantation (LT ). We determined risk factors for HAT occurring within 90 days post‐LT and analysed the effect of HAT on graft and patient survival. Donor and recipient demographics, surgery‐related data and outcome in transplants complicated by thrombosis (HAT +) and their matched controls (HAT ?) were compared. Risk factors were assessed by univariate logistic regression. Median (IQR ) is given. A total of 25 HAT occurred among 1035 adult LT (1/1997–12/2014) and 50 controls were manually matched. Donor and recipient demographics were similar. Pre‐LT trans‐catheter arterial chemo‐embolization (TACE ) was more frequent in HAT + (HAT + 20% vs. HAT ? 4%, P = 0.037). HAT + had longer implantation [HAT + 88 min (76–108) vs. HAT ? 77 min (66–93), P = 0.028] and surgery times [HAT + 6.25 h (5.18–7.47) vs. HAT ? 5.25 h (4.33–6.5), P = 0.001]. Early graft dysfunction and sepsis were more frequent in HAT + and hospitalization longer. TACE had the greatest odds ratio in unadjusted analysis (OR : 6, 95% CI : 1.07–33.53, P = 0.03). All but seven grafts were lost after HAT (HAT + 72% vs. HAT ? 36%, P = 0.003); however, patient survival was unaffected (HAT + 79.8% vs. HAT ? 76%, P = 0.75). LT candidates undergoing TACE are at risk of developing HAT early after transplant.     

A pilot study on early versus delayed hypertonic saline dextran resuscitation in a porcine model of near-lethal liver injury: early hemodynamic response and short-term survival

BACKGROUND: We studied the effects of early versus delayed fluid resuscitation on hemodynamic response and short-term survival in a porcine model of severe hepatic injury associated with hemorrhagic shock. MATERIALS AND METHODS: Eighteen anesthetized swine were randomized after standardized liver injury into two groups: early resuscitation (ER, n = 9) and delayed resuscitation (DR, n = 9). The ER and DR groups were resuscitated with hypertonic saline dextran (HSD) 20 min and 40 min after the injury, respectively. Mean arterial pressure (MAP), cardiac output (CO), and arterial blood gases were measured in addition to vascular blood flow rates in the aorta, hepatic artery and portal vein. The duration of follow-up was 100 min. RESULTS: MAP decreased from 112 +/- 4 to 23 +/- 2 mmHg (P < 0.05) during 20 min after the injury. Bolus infusion of HSD significantly elevated MAP, CO, and flow rates in the aorta, portal vein and common hepatic artery in both groups. Portal vein flow remained relatively high during the shock. Intra-abdominal bleeding (ER, 701 +/- 42 mL; DR 757 +/- 78 mL) and the mortality rate (ER 44%; DR 33%) did not differ between the groups 100 min after injury (P > 0.05). Aortic flow, portal vein flow, common hepatic artery flow, MAP, CO, PaO(2), PaCO(2), base deficit, pH, hemoglobin measurements, and the volume of blood shed into the intraperitoneal cavity did not affect survival in the Cox regression analysis. CONCLUSIONS: Early versus delayed fluid infusion with HSD resulted in a comparable hemodynamic response and survival 100 min after injury. No rebleeding was observed.