Risk factors associated with early hepatic artery thrombosis after orthotopic liver transplantation - univariable and multivariable analysis

Systematic Review and Meta-Analysis of the Outcomes After Hepatic Artery Reconstruction in Pediatric Liver Transplantation Using a Microscope Versus Surgical Loupe

BACKGROUND

To review the impact of the operating microscope (OM) for reconstruction of the hepatic artery (HA) by comparing the outcomes with standard loupe reconstruction (SL) in pediatric liver transplantation (LT).

METHODS

Studies comparing the application of OM and SL for the reconstruction of the HA in primary pediatric LT were included from a systematic search of MEDLINE, Cochrane Library and EMBASE from inception to June 2022. Re-transplantation, dual grafts and auxiliary transplants were excluded. Primary outcome was the rate of HA thrombosis (HAT). Secondary outcomes were graft loss and mortality.

RESULTS

There were 1261 liver recipients from 9 included studies published until June 2022. There were 484 patients in the OM group and 777 patients in the SL group. HAT incidence with OM was significantly lower with OR = 0.18 (95% CI: 0.07-0.48). The 1-year graft survival was significantly better in the OM group with OR = 2.77 (95% CI: 1.13-6.80). 1-year overall mortality was also significantly lower with OM with OR = 0.39 (0.18-0.86). The use of OM did not significantly impact the incidence of HAT in the living donor liver transplant subgroup. Differences in time for hepatic HA reconstruction, total operating time and length of hospital stay did not reach statistical significance.

CONCLUSION

The use of OM has reduced the risk of HAT, graft loss and mortality in pediatric liver transplantation. Adoption of microsurgical principles in general may have contributed to the improved outcomes with SL reconstruction of HA in pediatric LT.

Donor Atheromatous Disease is a Risk Factor for Hepatic Artery Thrombosis After Liver Transplantation

The increasing age of liver donors and transplant candidates, together with the growing prevalence of metabolic comorbidities, could impact the risk of vascular complications after liver transplantation. We enrolled a consecutive cohort of adult patients undergoing liver transplantation from 2012 to 2021 who had a blinded pathological assessment of atherosclerosis in the donor and recipient hepatic arteries (HA). Patients receiving partial or reduced grafts, retransplantation, or combined organ transplantation were excluded. The relationship between HA atherosclerosis and HA thrombosis after liver transplantation was evaluated using logistic regression in the whole study cohort and in a propensity score-matched subpopulation. Among 443 eligible patients, 272 had a full pathological evaluation of the donor and recipient HA and were included in the study. HA atheroma was present in 51.5% of donors and in 11.4% of recipients. HA thrombosis occurred in 16 patients (5.9%), being more likely in patients who received a donor with HA atherosclerosis than in those without (10.7% vs. 0.8%; p < 0.001). Donor HA atherosclerosis was an independent risk factor of HA thrombosis (OR = 17.79; p = 0.008), and this finding was consistent in the propensity score-matched analysis according to age, sex, complex arterial anastomosis, and alcoholic liver disease (OR = 19.29; p = 0.007). Atheromatous disease in the recipient had no influence on the risk of HA thrombosis (OR = 1.70; p = 0.55). In conclusion, patients receiving donors with HA atherosclerosis are at increased risk for HA thrombosis after liver transplantation. The evaluation of the donor graft vasculature could guide antiplatelet therapy in the postoperative period.

Prognostic value of ultrasound in early arterial complications post liver transplant

Liver transplantation is the primary therapeutic intervention for end-stage liver disease. However, vascular complications, particularly those involving the hepatic artery, pose significant risks to patients. The clinical manifestations associated with early arterial complications following liver transplantation are often nonspecific. Without timely intervention, these complications can result in graft failure or patient mortality. Therefore, early diagnosis and the formulation of an optimal treatment plan are imperative. Ultrasound examination remains the predominant imaging modality for detecting complications post liver transplantation. This article comprehensively reviews common causes and clinical presentations of early hepatic artery complications in the post-transplantation period and delineates abnormal sonographic findings for accurate diagnosis of these conditions. Overall, ultrasound offers the advantages of convenience, safety, effectiveness, and non-invasiveness. It enables real-time, dynamic, and precise evaluation, making it the preferred diagnostic method for post-liver transplantation assessments.

Vascular Complications After Liver Transplantation

OBJECTIVES

Vascular complications after liver transplant can be lethal. High levels of suspicion and aggressive use of diagnostic tools may help with early diagnosis and treatment. Here, we share our experiences regarding this topic.

MATERIALS AND METHODS

Adult and pediatric patients who had liver transplant between February 1997 and June 2018 in our clinic were included in the study. Patients were grouped according to age (pediatric patients were those under 18 years old), male versus female, indication for transplant, type of liver transplant, type of vascular complication, treatment, and survival aftertreatment.We analyzed the statistical incidence of vascular complications according to age, male versus female, and type of liver transplant.

RESULTS

Our analyses included 607 liver transplant procedures, including 7 retransplants, with 349 (57.4%) from living donors and 258 (42.6%) from deceased donors. Of total patients, 539 were adults (89.8%) and 61 were children (10.2%). Vascular complications occurred in 25 patients (4.1%), with hepatic artery complications seen in 13 patients (2.1%) (10 adults [1.8%] and 3 children [4.9%]), portal vein complications seen in 9 patients (1.5%) (6 adults [1.1%] and 3 children [4.9%]), and hepatic vein complications seen in 3 patients (0.5%) (2 adults [0.36%] and 1 child [1.6%]). Rate of vascular complications was statistically higher in pediatric patients (11.4% vs 3.3%; P = .007) and higher but not statistically in recipients of livers from living donors (5.2% vs 2.7%; P = .19). Twelve patients (48.8%) were treated with endovascular approach, and 11 (0.44%)required surgicaltreatment. Two patients underwent immediate retransplant due to hepatic artery thrombosis.

CONCLUSIONS

Because vascular complications are the most severe complications afterlivertransplant,there must be close follow-up of vascular anastomoses, particularly early postoperatively, with radiologic methods. In cases of vascular complications, emergent treatment, including endovascular interventions, surgery, and retransplant, must be performed.

Viscoelastic Management of Coagulopathy during the Perioperative Period of Liver Transplantation

Viscoelastic testing (VET) in liver transplantation (LT) has been used since its origin, in combination with standard laboratory testing (SLT). There are only a few, small, randomized controlled trials that demonstrated a reduction in transfusion rates using VET to guide coagulation management. Retrospective analyses contrasting VET to SLT have demonstrated mixed results, with a recent concern for overtreatment and the increase in postoperative thrombotic events. An oversight of many studies evaluating VET in LT is a single protocol that does not address the different phases of surgery, in addition to pre- and postoperative management. Furthermore, the coagulation spectrum of patients entering and exiting the operating room is diverse, as these patients can have varying anatomic and physiologic risk factors for thrombosis. A single transfusion strategy for all is short sighted. VET in combination with SLT creates the opportunity for personalized resuscitation in surgery which can address the many challenges in LT where patients are at a paradoxical risk for both life-threatening bleeding and clotting. With emerging data on the role of rebalanced coagulation in cirrhosis and hypercoagulability following LT, there are numerous potential roles in VET management of LT that have been unaddressed.

Perioperative prothrombin complex concentrate and fibrinogen administration are associated with thrombotic complications after liver transplant

BACKGROUND

Use of intraoperative prothrombin complex concentrates (PCC) and fibrinogen concentrate administration has been linked to thrombotic events. However, it is unknown if its use is associated with thrombotic events after liver transplant.

METHODS AND ANALYSIS

We conducted a post hoc analysis of a prospectively conducted registry database study on patients who underwent liver transplant between 2004 and 2017 at Heidelberg University Hospital, Heidelberg, Germany. Univariate and multivariate analyses were used to determine the association between PCC and fibrinogen concentrate administration and thrombotic complications.

RESULTS

Data from 939 transplantations were included in the analysis. Perioperative PCC or fibrinogen administration was independently associated with the primary composite endpoint Hepatic artery thrombosis (HAT), Portal vein thrombosis (PVT), and inferior vena cava thrombosis [adjusted HR: 2.018 (1.174; 3.468), p = 0.011]. PCC or fibrinogen administration was associated with the secondary endpoints 30-day mortality (OR 4.225, p < 0.001), graft failure (OR 3.093, p < 0.001), intraoperative blood loss, red blood cell concentrate, fresh frozen plasma and platelet transfusion, longer hospitalization, and longer length of stay in intensive care units (ICUs) (all p < 0.001). PCC or fibrinogen administration were not associated with pulmonary embolism, myocardial infarction, stroke, or deep vein thrombosis within 30 days after surgery.

CONCLUSION

A critical review of established strategies in coagulation management during liver transplantation is warranted. Perioperative caregivers should exercise caution when administering coagulation factor concentrate during liver transplant surgery. Prospective randomized controlled trials are needed to establish causality for the relationship between coagulation factors and thrombotic events in liver transplantation. Further studies should be tailored to identify patient subgroups that will likely benefit from PCC or fibrinogen administration.

Feasible management of median arcuate ligament syndrome in orthotopic liver transplantation recipients

BACKGROUND

In orthotopic liver transplantation (OLT) recipients, median arcuate ligament syndrome (MALS) is considered a risk factor for hepatic arterial thrombosis (HAT), which is dreadful for OLT recipients. Different alternative surgical procedures have been proposed to overcome the impact of MALS on transplantation, but clinical evidence is still scarce.

AIM

To evaluate the feasible surgical management of MALS to reduce complications in OLT patients.

METHODS

Data for 288 consecutive patients who underwent OLT at The First Hospital of Jilin University between January 2017 and July 2020 were retrospectively reviewed. The surgical management of median arcuate ligament (MAL) and modifications to the arterial anastomosis were recorded. The perioperative and long-term prognosis of MALS recipients were noted. Detailed preoperative and postoperative data of patients were analyzed in a descriptive manner.

RESULTS

Eight patients with MALS were included in this study. The first patient with MALS received no intervention during the primary surgery and developed postoperative HAT. Salvage liver transplantation with MAL division was successfully performed. Gastroduodenal artery (GDA) preservation with splenic artery ligation was performed on three patients, only GDA preservation was performed on two patients, and no intervention was performed on two patients. No patient developed HAT after surgery and postoperative recovery was satisfactory.

CONCLUSION

The preservation of collateral circulation between the superior mesenteric artery and celiac trunk via the GDA with or without splenic artery ligation is a safe and feasible alternative to MAL division.

Techniques of hepatic arterial reconstruction in liver transplantation

BACKGROUND

Hepatic artery reconstruction is an essential part of liver transplantation. This difficult stage of the operation is even more demanding in living donor liver transplantation than in deceased donor liver transplantation. One of the most important advances in hepatic artery reconstruction for living liver grafts was the introduction of microsurgical techniques involving an operative microscope or surgical loupe. Many surgical reconstruction techniques have been used in this field.

PURPOSE

In this article, first, we will talk about the hepatic artery reconstruction techniques that are frequently used in deceased donor liver transplantation, and afterward, we will talk about the hepatic artery reconstruction techniques used in living donor liver transplantation, which include the hepatic artery reconstruction technique we use and call "one stay corner suture technique".

CONCLUSIONS

We think high-volume transplant centers should tend to develop a standardized technique for doing hepatic artery reconstruction with their teams. We think the "one stay corner suture technique" can be easily applied in centers that perform LDLT.

Clinical Outcomes of Liver Transplantation for Patients Over 60 Years Old: A Single-Center Experience

OBJECTIVES

Although advanced age is no longer considered an absolute contraindication for liver transplant, transplant in elderly patients with comorbid diseases remains debatable because of high risks with surgery. Here, we report patient outcomes in this population.

MATERIALS AND METHODS

We retrospectively reviewed medical records of 276 liver transplant recipients, grouped by age. Group 1 (≤59 years old) consisted of 247 recipients, and group 2 (≥60 years old) consisted of 29 recipients. Reviewed data included age, sex, cause of liver disease, presence of hepatocellular carcinoma, Child-Pugh and Model for End-Stage Liver Disease scores, survival, and posttransplant complications.

RESULTS

In both groups, most patients (n = 108) required liver transplant for hepatitis B virus. Mean age was 40 ± 12.3 and 63 ± 2.3 years in groups 1 and 2, respectively, with more men than women in both group 1 (71.7% vs 28.3%) and group 2 (75.9% vs 24.1%). No significant differences were shown between groups for patient characteristics, except group 1 had significantly higher Model for End-Stage Liver Disease score. Group 1 mean survival time was 10.2 ± 0.6 years, with patient survival rates at 1, 5, 10, and 15 years of 65.5%, 53%, 46.3%, and 40%, respectively. In group 2, respective results were 10.6 ± 1.3 years and 75.9%, 68.6%, 61%, and 48.8% (no significant difference vs group 1).

CONCLUSIONS

Liver transplant recipients >60 years of age had survival rates, acute rejection rates, and complications similar to younger recipients. Liver transplant should not be withheld from older recipients on the basis of age alone. However, comprehensive screening for comorbidities should be performed.

Hip, vertebral, and wrist fracture risks and schizophrenia: a nationwide longitudinal study

BACKGROUND

Fractures are a great health issue associated with morbidity, quality of life, life span, and health care expenditure. Fractures are correlated with cardiovascular disease, type 2 diabetes mellitus, cerebrovascular disease, and some psychiatric disorders. However, representative national data are few, and longitudinal cohort studies on the association between schizophrenia and the subsequent fracture risk are scant. We designed a nationwide population-based cohort study to investigate the association of schizophrenia with hip, vertebral, and wrist fractures over a 10-year follow-up.

METHODS

Data of patients with schizophrenia (International Classification of Diseases, Ninth Revision, Clinical Modification code 295) and matched over January 2000-December 2009) were extracted from Taiwan National Health Insurance Research Database. A Cox proportional-hazards regression model was constructed to calculate hazard ratios (HRs) for fractures between the schizophrenia and control cohorts.

RESULTS

Of 2028 people with schizophrenia (mean age: 36.3 years, 49.4% female), 89 (4.4%) reported newly diagnosed fractures-significantly higher than the proportion in the control population (257, 3.2%; P = 0.007). The incidences of hip (1.2%, P = 0.009) and vertebral (2.6%, P = 0.011) fractures were significantly higher in the schizophrenia cohort than in the control cohort. In Cox regression analysis, hip (adjusted HR: 1.78, 95% confidence interval [CI]: 1.08-2.93) and vertebral (adjusted HR: 1.40, 95% CI: 1.01-1.95) fracture risks were significantly higher in patients with schizophrenia. Furthermore, a sex-based subgroup analysis revealed that the risk of hip fracture remained significantly higher in female patients with schizophrenia (HR: 2.68, 95% CI: 1.32-5.44) than in female controls. On the other hand, there was no significant interaction between effects of sex and schizophrenia on the risk of fractures.

CONCLUSIONS

Over a 10-year follow-up, hip and vertebral fracture risks were higher in the people with schizophrenia than in the controls. The risk of fractures in patients with schizophrenia does not differ between female and male.

The effect of end-ischaemic normothermic machine perfusion on donor hepatic artery endothelial integrity

BACKGROUND

Ex vivo normothermic machine liver perfusion (NMLP) involves artificial cannulation of vessels and generation of flow pressures. This could lead to shear stress-induced endothelial damage, predisposing to vascular complications, or improved preservation of donor artery quality. This study aims to assess the spatial donor hepatic artery (HA) endothelial quality downstream of the cannulation site after end-ischaemic NMLP.

METHODS

Remnant HA segments from the coeliac trunk up to the gastroduodenal artery branching were obtained after NMLP (n = 15) and after static cold storage (SCS) preservation (n = 15). Specimens were fixed in 10% neutral buffered formalin and sectioned at pre-determined anatomical sites downstream of the coeliac trunk. CD31 immunohistostaining was used to assess endothelial integrity by a 5-point ordinal scale (grade 0: intact endothelial lining, grade 5: complete denudation). Endothelial integrity after SCS was used as a control for the state of the endothelium at commencement of NMP.

RESULTS

In the SCS specimens, regardless of the anatomical site, near complete endothelial denudation was present throughout the HA (median scores 4.5-5). After NMLP, significantly less endothelial loss in the distal HA was present compared to SCS grafts (NMLP vs. SCS: median grade 3 vs. 4.5; p = 0.042). In NMLP specimens, near complete endothelial denudation was present at the cannulation site in all cases (median grade: 5), with significantly less loss of the endothelial lining the further from the cannulation site (proximal vs. distal, median grade 5 vs. 3; p = 0.005).

CONCLUSION

Loss of endothelial lining throughout the HA after SCS and at the cannulation site after NMLP suggests extensive damage related to surgical handling and preservation injury. Gradual improved endothelial lining along more distal sites of the HA after NMLP indicates potential for re-endothelialisation. The regenerative effect of NMLP on artery quality seems to occur to a greater extent further from the cannulation site. Therefore, arterial cannulation for machine perfusion of liver grafts should ideally be as proximal as possible on the coeliac trunk or aortic patch, while the site of anastomosis should preferentially be attempted distal on the common HA.

Prediction of Graft Survival Post-liver Transplantation by L-GrAFT Risk Score Model, EASE Score, MEAF Scoring, and EAD

Background: Early allograft dysfunction (EAD) is correlated with poor patient or graft survival in liver transplantation. However, the power of distinct definitions of EAD in prediction of graft survival is unclear. Methods: This retrospective, single-center study reviewed data of 677 recipients undergoing orthotopic liver transplant between July 2015 and June 2020. The following EAD definitions were compared: liver graft assessment following transplantation (L-GrAFT) risk score model, early allograft failure simplified estimation score (EASE), model for early allograft function (MEAF) scoring, and Olthoff criteria. Risk factors for L-GrAFT₇ high risk group were evaluated with univariate and multivariable logistic regression analysis. Results: L-GrAFT₇ had a satisfied C-statistic of 0.87 in predicting a 3-month graft survival which significantly outperformed MEAF (C-statistic = 0.78, P = 0.01) and EAD (C-statistic = 0.75, P < 0.001), respectively. L-GrAFT₁₀, EASE was similar to L-GrAFT₇, and they had no statistical significance in predicting survival. Laboratory model for end-stage liver disease score and cold ischemia time are risk factors of L-GrAFT₇ high-risk group. Conclusion: L-GrAFT₇ risk score is capable for better predicting the 3-month graft survival than the MEAF and EAD in a Chinese cohort, which might standardize assessment of early graft function and serve as a surrogate endpoint in clinical trial.

Transarterial chemoembolization of hepatocellular carcinoma before liver transplantation and risk of post-transplant vascular complications: a multicentre observational cohort and propensity score-matched analysis

BACKGROUND

Transarterial chemoembolization (TACE) in patients with hepatocellular cancer (HCC) on the waiting list for liver transplantation may be associated with an increased risk for hepatic artery complications. The present study aims to assess the risk for, primarily, intraoperative technical hepatic artery problems and, secondarily, postoperative hepatic artery complications encountered in patients who received TACE before liver transplantation.

METHODS

Available data from HCC liver transplantation recipients across six European centres from January 2007 to December 2018 were analysed in a 1 : 1 propensity score-matched cohort (TACE versus no TACE). Incidences of intraoperative hepatic artery interventions and postoperative hepatic artery complications were compared.

RESULTS

Data on postoperative hepatic artery complications were available in all 876 patients (425 patients with TACE and 451 patients without TACE). Fifty-eight (6.6 per cent) patients experienced postoperative hepatic artery complications. In total 253 patients who had undergone TACE could be matched to controls. In the matched cohort TACE was not associated with a composite of hepatic artery complications (OR 1.73, 95 per cent c.i. 0.82 to 3.63, P = 0.149). Data on intraoperative hepatic artery interventions were available in 825 patients (422 patients with TACE and 403 without TACE). Intraoperative hepatic artery interventions were necessary in 69 (8.4 per cent) patients. In the matched cohort TACE was not associated with an increased incidence of intraoperative hepatic artery interventions (OR 0.94, 95 per cent c.i. 0.49 to 1.83, P = 0.870).

CONCLUSION

In otherwise matched patients with HCC intended for liver transplantation, TACE treatment before transplantation was not associated with higher risk of technical vascular issues or hepatic artery complications.

An Orthotopic Liver Transplantation Patient Survived Without Hepatic Artery Flow Due to Thrombosis: A Case Report

BACKGROUND

Hepatic artery thrombosis (HAT), a serious complication after orthotopic liver transplantation, almost always leads to morbidity and mortality without urgent revascularization or retransplantation, especially if HAT occurs within a few days after transplantation.

CASE PRESENTATION

Herein we describe a case report of an orthotopic liver transplantation patient surviving without hepatic artery flow due to HAT on postoperative day 1. Reanastomosis, thrombectomy, and intra-arterial thrombolysis were performed, but only retrograde arterial flow by Doppler ultrasound, not by angiography, could be demonstrated in the hepatic artery. This case report is in compliance with the Declaration of Helsinki and the Declaration of Istanbul.

CONCLUSION

Based on the evidence from this patient, we believe that patients with failed revascularization can experience a long-term survival with conservative treatment. Retransplantation should be evaluated based on laboratory findings because graft function in individual patients can recover.

Complications of liver transplant

Liver transplantation has become a definitive treatment for patients with end-stage liver disease and those meeting Milan criteria for hepatocellular carcinoma. The morbidity and mortality associated with liver transplantation continues to decrease thanks to refinements in surgical technique, immunosuppression, and imaging. In particular, imaging plays a vital role by facilitating early detection of post-operative complications and enabling prompt treatment. Post-operative complications that lead to graft failure and patient morbidity/mortality can be generally categorized as vascular, biliary, parenchymal, and malignant. Vascular complications include stenosis and thrombosis of the hepatic artery, portal vein, and inferior vena cava; hepatic artery pseudoaneurysm; arteriovenous fistula; and celiac stenosis. Biliary abnormalities include strictures, bile leak, obstruction, recurrent disease, and infection. While imaging is not primarily utilized to diagnose allograft rejection, it plays an important role in excluding mechanical causes of graft dysfunction that can mimic rejection. Ultrasound is routinely performed as the first-line imaging evaluation for the detection and follow-up of early and delayed complications. Cholangiography and magnetic resonance cholangiopancreatography are useful in detecting and characterizing biliary complications. Computed tomography is often used to further evaluate abnormal findings on ultrasound or for the characterization of post-operative fluid collections. The aim of this review is to discuss and illustrate the imaging findings of complications associated with liver transplantation and their role in facilitating treatment.

The learning curve for piggyback liver transplantation: identifying factors challenging surgery

BACKGROUND

This study aimed to quantify the learning curve of piggyback liver transplantation and to identify factors that impact the operative time and blood transfusion during the learning curve.

METHODS

A retrospective review was performed on consecutive cases of patients' first piggyback liver transplantations that were performed by a single surgeon. The learning curve for the operative time was evaluated using the cumulative sum method.

RESULTS

There were 181, consecutive, first-time piggyback liver transplantations. The median operative time was 345 minutes (range: 180-745 minutes) with a median transfusion rate of 4 packed red blood cell units (range: 0-23 units). The cumulative sum learning curve identified 3 phases: an initial phase (1-70 piggyback liver transplantations), a plateau phase (71-101 piggyback liver transplantations), and a stable phase (102-181 piggyback liver transplantations). Over the 3 phases, there were significant decreases in the median duration of the surgery (388.8 vs 344.8 vs 326.9 minutes; P = .004, P = .0004, P ≤ .0001) and the number of red blood cell units transfused (6.00 vs 3.90 vs 3.71; P = .02, P = .79, P = .0006). Multivariable analysis identified that the following factors impacted the operative time: surgeon experience (P = .00006), previous upper abdominal surgery (P = .01), portocaval shunt fashioning (P = .0003), early portal section (P = .00001), multiple arterial graft reconstruction (P = .03), and the length of the retrohepatic inferior vena covered by segment 1 (P = .0006). Independent risk factors for increased blood loss were surgeon experience (P = .0001), previous upper abdominal surgery (P = .002), the retrohepatic inferior vena cava encirclement by segment 1 (P = .0001), severe portal hypertension (P = .01), early portal section (P = .001), and low prothrombin time (P = .00001).

CONCLUSION

Easily identifiable factors related to recipients (segment 1 morphology, previous upper abdominal surgery, severe portal hypertension) and to surgeon (operative experience, portocaval shunt fashioning, early portal section, and multiple arterial reconstructions) impact operative time and blood loss during the learning curve of piggyback liver transplantation. These factors can be used for grading the difficulties of liver transplantation to tailor the surgical strategy.

Decreased Incidence of Hepatic Artery Thrombosis in Pediatric Liver Transplantation Using Technical Variant Grafts: Report of the Society of Pediatric Liver Transplantation Experience

OBJECTIVE

To evaluate risk factors for hepatic artery thrombosis (HAT) and examine the long-term outcomes of graft and patient survival after HAT in pediatric recipients of liver transplantation.

STUDY DESIGN

Using multicenter data from the Society of Pediatric Liver Transplantation, Kaplan-Meier and Cox regression analyses were performed on first-time pediatric (aged <18 years) liver transplant recipients (n = 3801) in the US and Canada between 1995 and 2016.

RESULTS

Of children undergoing their first liver transplantation, 7.4% developed HAT within the first 90 days of transplantation and, of those who were retransplanted, 20.7% developed recurrent HAT. Prolonged warm ischemia times increased the odds of developing HAT (OR, 1.11; P = .02). Adolescents aged 11-17 years (OR, 0.53; P = .03) and recipients with split, reduced, or living donor grafts had decreased odds of HAT (OR, 0.59; P < .001 compared with whole grafts). Fifty percent of children who developed HAT developed graft failure within the first 90 days of transplantation (adjusted hazard ratio, 11.87; 95% CI, 9.02-15.62) and had a significantly higher post-transplant mortality within the first 90 days after transplantation (adjusted hazard ratio, 6.18; 95% CI, 4.01-9.53).

CONCLUSIONS

These data from an international registry demonstrate poorer long-term graft and patient survival in pediatric recipients whose post-transplant course is complicated by HAT. Notably, recipients of technical variant grafts had lower odds of HAT compared with whole liver grafts.

Reconstruction of the hepatic artery using the superior mesenteric artery for liver transplantation

Background

To investigate the application of the superior mesenteric artery (SMA) for the in vitro reconstruction of the hepatic artery for liver transplantation, and to improve the success rate and safety of donor liver transplantation.

Methods

The donor liver and the pancreas were obtained, and the SMA and its branches were used to reconstruct the hepatic artery. Liver transplantation was performed after reconstruction to understand the intraoperative situation after donor liver opening, as well as postoperative liver function. Color Doppler ultrasound of the transplanted liver was also performed.

Results

During the period from September 2016 to March 2020, a total of 98 pancreases were obtained. The common hepatic artery and gastroduodenal artery loop (CHA-GDA) were preserved to the donor pancreas, and only the proper hepatic artery (PHA) or left/right hepatic artery (LHA/RHA) were preserved to the donor liver. If the PHA of the donor liver was short or absent, the SMA was used for lengthening the PHA or in vitro reconstruction of the LHA/RHA, followed by implantation of the donor liver after reconstruction. A total of 17 cases of this type of donor liver required mesenteric artery lengthening or reconstruction. After opening, the donor liver was well-filled, bile secretion was normal, and liver function recovered as scheduled after surgery. Color Doppler ultrasound and CT angiography (CTA) of the transplanted liver revealed that hepatic arteries were normal without complications such as hepatic artery embolism.

Conclusions

In vitro reconstruction of the hepatic artery with the SMA is an effective new method of vascular reconstruction, which ensures the blood flow of the hepatic artery, reduces the anastomosis difficulty of the arteries of the donor liver, and reduces the occurrence of vascular complications.

Additional value of superb microvascular imaging for assessing hepatic arterial blood flow after pediatric liver transplantation

BACKGROUND

The aim of this study was to explore the value of SMI compared with conventional ultrasonography for assessing hepatic arterial blood flow after pediatric liver transplantation.

METHODS

From March 2018 to November 2018, a total of 105 pediatric recipients with biliary atresia underwent liver transplantation in our hospital. Ultrasound examinations were performed at the bedside in the intensive care unit to check the patency of the blood flow in the hepatic allograft. CDI, PDI, cSMI, and mSMI were performed to assess the display, orientation, and distribution of the graft hepatic artery. Ultrasound examinations were performed by one radiologist, and the images were judged by two observers.

RESULTS

The median age, weight, and height of the recipients were 6.97 (5.92, 9.58) months, 6.50 (6.00, 7.80) kg, and 64.00 (62.00, 68.00) cm, respectively. The measure of kappa agreement was 0.902, 0.889, 0.882, and 0.882 for CDI, PDI, cSMI, and mSMI, respectively. HAT occurred in 7 pediatric recipients and was confirmed by CTA (computed tomography angiography) and surgery. The diagnostic performance of sensitivity, specificity, PPV (positive predictive value), NPV (negative predictive value), and accuracy were 100%, 92.86%, 50%, 100%, and 93.33% for CDI and 100%, 98.98%, 87.50%, 100%, and 99.05% for SMI.

CONCLUSIONS

As an additional method to CDI, SMI can clearly show the distribution of hepatic arterial blood flow and provide more details, thereby markedly improving the diagnostic performance of postoperative HAT.

Pyogenic liver abscess in liver transplant recipient: A warning signal for the risk of recurrence and retransplantation

BACKGROUND

Pyogenic liver abscesses in liver transplant recipients (PLA-LTR) are a rare disease whose specificities compared with PLA in non-transplanted patients (PLA-C) are unknown.

METHODS

A retrospective case-control study was conducted in a French academic hospital from January 1, 2010, to December 31, 2014.

RESULTS

Among 176 patients diagnosed with PLA, 14 were LTR; each case was matched with 3 PLA-C controls by date of PLA diagnosis and pathophysiological mechanism of PLA. Median time from liver transplantation to PLA diagnosis was 34.5 months. Among 14 PLA-LTR, 8/14 (57.1%) had bacteremia and 10/14 (71.4%) had positive PLA cultures. Most commonly isolated bacteria were Enterobacteriaceae (9/14; 64.3%), Enterococcus spp. (4/14; 28.6%), and anaerobic bacteria (3/14; 21.4%). Clinical, radiological, and microbiological characteristics did not significantly differ between PLA-LTR and PLA-C but there was a tendency toward more diabetic patients and a less acute presentation. All but one PLA-LTR were associated with ischemic cholangitis, whereas this was a rare cause among PLA-C (13/14 vs 3/42, respectively, P < .001) among patients with PLA-LTR. In contrast, hepatobiliary neoplasia was rare in PLA-LTR but frequent in PLA-C (1/14 vs 24/42, P = .001). No significant difference was found between PLA-LTR and PLA-C in terms of duration of antibiotic therapy (6.5 and 6 weeks, respectively), PLA drainage rates (10/14 and 26/42, respectively), or mortality at 12 months after PLA diagnosis (2/14 and 5/42, respectively). Recurrence rates within the first year were observed in 6/14 patients (42.9%), and retransplantation was needed in 5/14 (35.7%).

CONCLUSIONS

Occurrence of PLA in LTR is a severe event leading to high risk of recurrence and retransplantation.

Endovascular Treatment of Aortohepatic Conduit Stenosis Following Liver Transplant

BACKGROUND

Aortohepatic conduits (AHCs) are valuable alternatives when conventional hepatic artery anastomoses are not possible. However, AHCs have earlier and higher occlusion rates and reduced graft and patient survival. While endovascular therapy is safe and effective for conventional anastomotic stenoses, data on AHC stenoses are limited. This study reviewed outcomes for endovascular management of AHC stenosis at a single liver transplant center.

METHODS

A retrospective review of a prospectively maintained database was performed on the endovascular management of AHC stenosis between January 1, 2000, and December 31, 2016. Medical records, laboratory data, and imaging were analyzed for technical and hemodynamic success, primary and assisted primary patency, and patient and graft survival.

RESULTS

Seven patients underwent angioplasty a median of 142 days after transplant, and 2 required reintervention. The primary patency rate was 67% at 6 months and 22% at 1 year. The assisted primary patency rate was 83% at 6 months and 42% at 1, 3, and 5 years. Patient and graft survival were 86% at 6 months and 71%, 57%, and 38% at 1, 3, and 5 years, respectively. Four conduits were patent at last follow-up. There were no major adverse events after angioplasty. One reintervention was complicated by acute AHC thrombosis after stenting, causing biliary necrosis, sepsis, and death. There was no 30-day mortality, retransplant, or surgical revascularization because of endovascular intervention.

CONCLUSIONS

Endovascular treatment of AHC stenosis appears to be safe with a high technical success rate but lower long-term patency than standard hepatic arterial anastomoses.

Impact of Hepatic Artery Thrombosis on the Success of a Liver Transplant Because of Hepatocellular Carcinoma

BACKGROUND

Hepatic artery thrombosis is one of the most serious complications after liver transplant. Our objective is to evaluate the impact of arterial thrombosis on the postoperative evolution of a series of patients who received transplants because of hepatocellular carcinoma.

METHODS

A retrospective study of 100 consecutive hepatocellular carcinoma liver transplants was performed from January 2011 to November 2017.

RESULTS

Of the 100 transplant recipients, we have observed hepatic artery thrombosis in 4 of them, 3 premature and 1 delayed. All of them received retransplants after diagnosis by hepatic artery ultrasonography and arteriography. The descriptive analysis showed a significant relationship between the appearance of hepatic artery thrombosis with variables of postoperative severity, such as arrhythmias, atelectasis, pleural effusion, hemodialysis requirement, acute kidney failure, and respiratory failure. Although patients with hepatic artery thrombosis had a longer mean hospital stay, this was not statistically significant. There was decreased graft survival and overall survival of patients who experienced hepatic artery thrombosis.

CONCLUSION

Although the incidence of hepatic artery thrombosis has been relatively low (4%), the early detection of risk factors, such as arterial anatomic anomalies that condition a complex anastomosis, should draw our attention, thus having at our disposal strict ultrasonography and arteriography surveillance protocols as well as prophylactic anticoagulation guidelines for receptors at risk.

Perioperative management of antithrombotic treatment

End-stage liver disease is characterized by multiple and complex alterations of hemostasis that are associated with an increased risk of both bleeding and thrombosis. Liver transplantation further challenges the feeble hemostatic balance of patients with decompensated cirrhosis, and the management of antithrombotic treatment during and after transplant surgery, which is particularly difficult. Bleeding was traditionally considered the major concern during and early after surgery, but it is increasingly recognized that transplant recipients may also develop thrombotic complications. Pathophysiology of hemostatic complications during and after transplantation is multifactorial and includes pre-, intra-, and postoperative risk factors. Risk stratification is important, as it helps the identification of high-risk recipients in whom antithrombotic prophylaxis should be considered. In recipients who develop thrombosis during or after surgery, prompt treatment is indicated to prevent graft failure, retransplantation, and death.

One-Year Recipient Morbidity of Liver Transplantation Using Pure Laparoscopic Versus Open Living Donor Right Hepatectomy: Propensity Score Analysis

Donor safety and graft results of pure laparoscopic living donor right hepatectomy (LLDRH) have previously been compared with those of open living donor right hepatectomy (OLDRH). However, the clinical outcomes of recipients at 1-year follow-up have never been accurately compared. We aimed to compare 1-year outcomes of recipients of living donor right liver transplantation (LRLT) using pure LLDRH and OLDRH. From May 2013 to May 2017, 197 consecutive recipients underwent LRLT. Donor hepatectomies were performed either by OLDRH (n = 127) or pure LLDRH (n = 70). After propensity score matching, 53 recipients were included in each group for analysis. The clinical outcomes at 1-year follow-up were compared between the 2 groups. The primary outcome was recipient death or graft failure during the 1-year follow-up period. In the propensity-matched analysis, the incidence of death or graft failure during the 1-year follow-up period was not different between the 2 groups (3.8% versus 5.7%; odds ratio [OR], 1.45; 95% confidence interval [CI], 0.24-8.95; P = 0.69). However, the composite of Clavien-Dindo 3b-5 complications was more frequent in the pure LLDRH group (OR, 2.62; 95% CI, 1.15-5.96; P = 0.02). In conclusion, although pure LLDRH affords a comparable incidence of fatal complications in recipients, operative complications may increase at the beginning of the program. The safety of the recipients should be confirmed to accept pure LLDRH as a feasible option.

Comparison of Supraceliac and Infrarenal Aortic Conduits in Liver Transplantation: Is There a Difference in Patency and Postoperative Renal Dysfunction?

Aorto-hepatic conduits can provide arterial inflow for liver transplants in cases where the native hepatic artery is unsuitable for use.

Median Arcuate Ligament Compression in Orthotopic Liver Transplantation: Results from a Single-Center Analysis and a European Survey Study

Median arcuate ligament compression (MALC) potentially causes arterial complications in orthotopic liver transplantation (OLT). Here we aimed to investigate the incidence of MALC and its impact on clinical outcome after OLT. In addition, we performed an international survey among 52 European liver transplant centers to explore local protocols on the management of these patients. Data of 286 consecutive OLT recipients from a prospective database were analyzed retrospectively (05/2010-07/2017). Preoperative computed-tomography images were evaluated. Celiac axis stenosis due to MALC was found in 34 patients (12%). Intrinsic stenosis was present in 16 (6%) patients. Twenty-six patients (77%) with MALC underwent standard arterial revascularization with median arcuate ligament (MAL)-division. Patients treated for MALC had comparable baseline data and no difference was found in early- and long-term outcome compared to the rest of our cohort. Our survey found heterogeneous strategies regarding diagnosis and treatment of MALC. Only 29% of the centers reported the division of MAL in these patients as routine procedure. Even though there is no consensus on diagnosis and management of MALC among European centers, a surgical division of MAL is feasible and safe and should be considered in OLT recipients with MALC.

A systematic review and meta-analysis of rescue revascularization with arterial conduits in liver transplantation

Although aortohepatic conduits (AHCs) provide an effective technique for arterialization in liver transplantation (LT) when the native recipient artery is unusable, various publications report higher occlusion rates and impaired outcome compared to conventional anastomoses. This systematic review and meta-analysis investigates the published evidence of outcome and risk of AHCs in LT using bibliographic databases and following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Primary and secondary outcome were artery occlusion as well as graft and patient survival. Twenty-three retrospective studies were identified with a total of 22 113 patients with LT, of whom 1900 patients (9%) received an AHC. An AHC was used in 33% of retransplantations. Early artery occlusion occurred in 7% (3%-16%) of patients with AHCs, compared to 2% (1%-3%) without conduit (OR 3.70; 1.63-8.38; P = .001). The retransplantation rate after occlusion was not significantly different in both groups (OR 1.46; 0.67-3.18; P = .35). Graft (HR 1.38; 1.17-1.63; P < .001) and patient (HR 1.57; 1.12-2.20; P = .009) survival was significantly lower in the AHC compared to the nonconduit group. In contrast, graft survival in retransplantations was comparable (HR 1.00; 0.82-1.22; P = .986). Although AHCs provide an important rescue option, when regular revascularization is not feasible during LT, transplant surgeons should be alert of the potential risk of inferior outcome.

Overdose of Tacrolimus as the Trigger Causing Progression of Posterior Reversible Encephalopathy Syndrome and Subsequent Hepatic Infarction After Liver Transplant: A Case Report

Posterior reversible encephalopathy syndrome is a neurotoxic state accompanied by unique brain imaging patterns and neurologic abnormalities, typically associated with several complex clinical conditions such as preeclampsia/eclampsia, solid-organ transplant procedures, autoimmune diseases, and immunosuppressive agents. The detailed mechanism of posterior reversible encephalopathy syndrome is not known, and the current therapy is only supportive care. Here, we present a 33-year-old parturient woman with preeclampsia complicated with hemolysis, elevated liver enzymes, and low platelet syndrome, fulminant hepatitis B, acute fatty liver, and posterior reversible encephalopathy syndrome. The patient developed gross hepatic infarction soon after liver transplant. After several possible causes were excluded, we found that progression of underlying posterior reversible encephalopathy syndrome-induced endothelial damage by overdose of tacrolimus may have been the major cause for deteriorating hypoperfusion of the transplanted liver and fatal graft failure. In liver transplant recipients, severe posttransplant hypoperfusion of the grafted liver may result in loss of the liver allograft and even mortality. Poor control of underlying posterior reversible encephalopathy syndrome-associated endothelial damage because of tacrolimus overdose may lead to severe hypoperfusion of grafted hepatic vessels and subsequent hepatic infarction. This report highlights tacrolimus as a potential trigger of posterior reversible encephalopathy syndrome and may inform clinical decisions regarding tacrolimus administration in liver transplant recipients with preexisting or newly developed posterior reversible encephalopathy syndrome.

Association between viscoelastic tests-guided therapy with synthetic factor concentrates and allogenic blood transfusion in liver transplantation: a before-after study

Background

Perioperative bleeding and transfusion are important causes of morbidity and mortality in patients undergoing liver transplantation. The aim of this study is to assess whether viscoelastic tests-guided therapy with the use of synthetic factor concentrates impact transfusion rates of hemocomponents in adult patients undergoing liver transplantation.

Methods

This is an interventional before-after comparative study. Patients undergoing liver transplantation before the implementation of a protocol using thromboelastometry and synthetic factor concentrates were compared to patients after the implementation. Primary outcome was transfusion of any hemocomponents. Secondary outcomes included: transfusion of red blood cells (RBC), fresh frozen plasma (FFP), cryoprecipitate or platelets, clinical complications, length of stay and in-hospital mortality.

Results

A total of 183 patients were included in the control and 54 in the intervention phase. After propensity score matching, the proportion of patients receiving any transfusion of hemocomponents was lower in the intervention phase (37.0 vs 58.4%; OR, 0.42; 95% CI, 0.20–0.87; p = 0.019). Patients in the intervention phase received less RBC (30.2 vs 52.5%; OR, 0.21; 95% CI, 0.08–0.56; p = 0.002) and FFP (5.7 vs 27.3%; OR, 0.11; 95% CI, 0.03–0.43; p = 0.002). There was no difference regarding transfusion of cryoprecipitate and platelets, complications related to the procedure, hospital length of stay and mortality.

Conclusions

Use of a viscoelastic test-guided transfusion algorithm with the use of synthetic factor concentrates reduces the transfusion rates of allogenic blood in patients submitted to liver transplantation.

Trial registration

This trial was registered retrospectively on November 15th, 2018 – clinicaltrials.gov – Identifier: NCT03756948.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0664-8) contains supplementary material, which is available to authorized users.

Hepatic artery occlusion in liver transplantation: What counts more, the type of reconstruction or the severity of the recipient's disease?

Although the type of hepatic artery revascularization technique is known to have an impact on patency rates, independent perioperative risk factors on patient outcomes are poorly defined. All consecutive adult patients undergoing cadaveric liver transplantation (n = 361) from July 2007 to June 2016 in a single institution were analyzed. Primary outcomes were early (<30 days) hepatic artery occlusion and primary hepatic artery patency rate. A multivariate model was used to identify independent risk factors for occlusion and the need of arterial conduit, as well as their impact on graft and patient survival. Arterial revascularization without additional reconstruction (end-to-end arterial anastomosis [AA]) was performed in 77% (n = 279), arterial reconstruction (AR) in 15% (n = 53), and aortohepatic conduit (AHC) in 8% (n = 29) of patients. AHC had the highest mean intraoperative flow (275 mL/minute; P = 0.02) compared with AA (250 mL/minute) and AR (200 mL/minute; P = 0.02). There were 43 recipients (12%) who had an occlusive event with successful revascularization in 20 (47%) recipients. One-year primary patency rates of AA, AR, and AHC were 97%, 88%, and 74%, respectively. Aortic calcification had an impact on early occlusion. AR (odds ratio [OR], 3.68; 95% confidence interval [CI], 1.26-10.75; P = 0.02) and AHC (OR, 6.21; 95% CI, 2.02-18.87; P = 0.001) were independent risk factors for early occlusion. Dyslipidemia additionally independently contributed to early occlusion (OR, 2.74; 95% CI, 0.96-7.87; P = 0.06). The 1- and 5-year graft survival rates were 83% and 70% for AA, 75% and 69% for AR, and 59% and 50% for AHC (P = 0.004), respectively. In conclusion, arterial patency is primarily determined by the type of vascular reconstruction rather than patient or disease characteristics. The preoperative lipid status is an independent risk factor for early occlusion, whereas overall occlusion is only based on the performed vascular reconstruction, which is also associated with reduced graft and patient survival. Liver Transplantation 24 790-802 2018 AASLD.

Impact of aberrant left hepatic artery ligation on the outcome of liver transplantation

The preservation of a graft's aberrant left hepatic artery (LHA) during liver transplantation (LT) ensures optimal vascularization of the left liver but can also be considered a risk factor for hepatic artery thrombosis (HAT). In contrast, ligation of an aberrant LHA may lead to hepatic ischemia with the potential risk of graft dysfunction and biliary complications. The aim of this study was to prospectively analyze the impact on the surgical strategy for LT of 5 tests performed to establish whether an aberrant LHA was an accessory or a replaced artery, thus leading to the design of a decisional algorithm. From August 2005 to December 2016, 395 whole LTs were performed in 376 patients. Five parameters were evaluated to determine whether an aberrant LHA was an accessory or a replaced artery. On the basis of our decision algorithm, an aberrant LHA was ligated during surgery when assessed as accessory and preserved when assessed as replaced. A total of 138 anatomical variants of hepatic arterial vascularization occurred in 120/395 (30.4%) grafts. Overall, the incidence of an aberrant LHA was 63/395 (15.9%). The LHA was ligated in 33 (52.4%) patients and preserved in 30 (47.6%) patients. After a mean follow-up period of 50.9 ± 39.7 months, the incidence of HAT, primary nonfunction, early allograft dysfunction, biliary stricture or leaks, and overall survival was similar in the 2 groups. In conclusion, once shown to be an accessory, an LHA can be safely ligated without clinical consequences on the outcome of LT. Liver Transplantation 24 204-213 2018 AASLD.

Hepatic artery and biliary complications in liver transplant recipients with radioembolization bridging treatment for hepatocellular carcinoma

BACKGROUND

Locoregional bridging treatments are commonly applied in patients with hepatocellular carcinoma (HCC) prior to liver transplantation to prevent tumor progression during waiting time. It remains unknown whether pre-transplant radioembolization treatment may increase the prevalence of hepatic artery and biliary complications post-transplant.

METHODS

We performed a retrospective review of 173 consecutive patients with HCC who underwent liver transplantation at our transplant center between January 2007 and December 2016.

RESULTS

Radioembolization bridging treatment was applied in 42 patients while 131 patients received other or no forms of bridging treatment. The overall prevalence of intra-operative and early post-operative hepatic artery complications was 9.5% in the radioembolization group and 9.2% in the control group (P = 1.000). Biliary complications were significantly less frequent in the radioembolization group (4.8% vs 17.6%, P = .0442). In multivariable analysis, radioembolization was not significantly associated with an increased risk of arterial complications. Considering biliary complications, radioembolization bridging treatment was the only factor significantly associated with decreased odds (OR 0.187 (0.039, 0.892), P = .036).

CONCLUSIONS

Radioembolization is not associated with higher odds of hepatic artery complications following liver transplantation. There may even be a protective effect regarding biliary complications. Radioembolization as a bridge to transplantation may effectively be applied without compromising successful liver transplantation.

Identifying independent risk factors for graft loss after primary liver transplantation

PURPOSE

The aim of the study is the identification of independent risk factors for re-transplantation after primary liver transplantation beyond the occurrence of hepatic artery thrombosis.

METHODS

Eight hundred thirty-four adult patients undergoing primary liver transplantation were analyzed. A propensity score was developed using multivariable binary logistic regression with hepatic artery thrombosis as the dependent variable. The logit link function of the propensity score was included into multivariable Cox regression analysis for graft survival to adjust the study population.

RESULTS

Graft loss was observed in 134 patients (16.1%). Independent significant risk factors for graft loss were recipient platelet count (p = 0.040; HR: 1.002; 95%-CI: 1.000-1.003), preoperative portal vein thrombosis (p = 0.032; HR: 1.797; 95%-CI: 1.054-2.925), donor age (p < 0.001; HR: 1.026; 95%-CI: 1.012-1.040), percentage of macrovesicular steatosis of the graft (p = 0.011; HR: 1.037; 95%-CI: 1.009-1.061), early complications leading to revision surgery (p < 0.001; HR: 2.734; 95%-CI: 1.897-3.956), duration of the transplant procedure (p < 0.001; HR: 1.005; 95%-CI: 1.003-1.007) as well as transplantation of a split liver graft (p = 0.003; HR: 2.637; 95%-CI: 1.420-4.728). The logit of the propensity score did not reach statistical significance in the final multivariable Cox regression model (p = 0.111) indicating good adjustment for the occurrence of hepatic artery thrombosis.

CONCLUSION

Liver transplant programs might benefit from regular donor organ biopsies to assess the amount of macrovesicular steatosis. An elevated recipient platelet count can promote reperfusion injury leading to graft loss. A liver graft from an elderly donor should not be split or be transplanted in a recipient with detected portal vein thrombosis.

Coagulopathy Before and After Liver Transplantation: From the Hepatic to the Systemic Circulatory Systems

The hemostatic environment in patients with cirrhosis is a delicate balance between prohemostatic and antihemostatic factors. There is a lack of effective laboratory measures of the hemostatic system in patients with cirrhosis. Many are predisposed to pulmonary embolus, deep vein thrombosis, and portal vein thrombosis in the pretransplantation setting. This pretransplantation hypercoagulable milieu seems to extend for at least several months post-transplantation. Patients with nonalcoholic fatty liver disease, inherited thrombophilia, portal hypertension in the absence of cirrhosis, and hepatocellular carcinoma often require individualized approach to anticoagulation. Early reports suggest a potential role for low-molecular-weight heparins and direct-acting anticoagulants.

The role of arterial conduits for revascularisation in adult orthotopic liver transplantation

The successful outcome in orthotopic liver transplantation (OLT) is critically dependent on the uncompromised hepatic graft blood inflow. Arterial conduits represent a good solution in cases where conventional revascularisation is not possible. The purpose of this systematic review is to analyse the published evidence on the use of arterial conduits in adult OLT. After review of the Pubmed and EMBASE databases, 19 relevant studies were identified and analysed. Even though patient survival was comparable, most large studies reported worse 1-, 3- and 5-year graft survival rates compared to grafts with standard arterial revascularisation. Primary grafts were more commonly affected than re-grafts. Early and late hepatic artery thrombosis occurred more commonly, while the use of an arterial conduit was identified as an independent risk factor. The overall biliary complications were comparable, however, ischaemic cholangiopathy was encountered about 3 times more in patients with arterial conduits and strongly correlated with the occurrence of late HAT. In conclusion, the use of arterial conduit is a useful option in adult OLT in cases that the conventional revascularisation technique cannot be used or results in suboptimal arterial inflow. More studies directly addressing issues such as pre-operative evaluation regarding the need for arterial conduit, the types of vessels used, positioning of the conduit and post-operative management are required.

Liver transplant recipients with portal vein thrombosis receiving an organ from a high-risk donor are at an increased risk for graft loss due to hepatic artery thrombosis

We hypothesize that recipients with pretransplant portal vein thrombosis (PVT) receiving organs from high-risk donors (HRD) are at an increased risk of HAT. Data on all liver transplants in the United States from February 2002 to March 2015 were analyzed. Recipients were sorted into two groups: those with PVT and those without. HRDs were defined by donor risk index (DRI) >1.7. Multivariable logistic regression models were constructed to assess the independent risk factors for HAT with the resultant graft loss ≤90 days from transplantation. A total of 60 404 candidates underwent liver transplantation; of those recipients, 623 (1.0%) had HAT, of which 66.0% (n = 411) received organs from HRDs compared with 49.3% (n = 29 473) in recipients without HAT (P < 0.001); 2250 (3.7%) recipients had pretransplantation PVT and received organs from HRDs. On adjusted multivariable analysis, PVT with a HRD organ was the most significant independent risk factor (OR 3.56, 95% CI 2.52-5.02, P < 0.001) for the development of HAT. Candidates with pretransplant PVT who receive an organ from a HRD are at the highest risk for postoperative HAT independent of other measurable factors. Recipients with pretransplant PVT would benefit from careful donor selection and possibly anticoagulation perioperatively.

Doppler ultrasonography in living donor liver transplantation recipients: Intra- and post-operative vascular complications

Living-donor liver transplantation has provided a solution to the severe lack of cadaver grafts for the replacement of liver afflicted with end-stage cirrhosis, fulminant disease, or inborn errors of metabolism. Vascular complications remain the most serious complications and a common cause for graft failure after hepatic transplantation. Doppler ultrasound remains the primary radiological imaging modality for the diagnosis of such complications. This article presents a brief review of intra- and post-operative living donor liver transplantation anatomy and a synopsis of the role of ultrasonography and color Doppler in evaluating the graft vascular haemodynamics both during surgery and post-operatively in accurately defining the early vascular complications. Intra-operative ultrasonography of the liver graft provides the surgeon with useful real-time diagnostic and staging information that may result in an alteration in the planned surgical approach and corrections of surgical complications during the procedure of vascular anastomoses. The relevant intra-operative anatomy and the spectrum of normal and abnormal findings are described. Ultrasonography and color Doppler also provides the clinicians and surgeons early post-operative potential developmental complications that may occur during hospital stay. Early detection and thus early problem solving can make the difference between graft survival and failure.

Pre-transplant portal vein thrombosis is an independent risk factor for graft loss due to hepatic artery thrombosis in liver transplant recipients

BACKGROUND

Hepatic artery thrombosis is an uncommon but catastrophic complication following liver transplantation. We hypothesize that recipients with portal vein thrombosis are at increased risk.

METHODS

Data on all liver transplants in the U.S. during the MELD era through September 2014 were obtained from UNOS. Status one, multivisceral, living donor, re-transplants, pediatric recipients and donation after cardiac death were excluded. Logistic regression models were constructed for hepatic artery thrombosis with resultant graft loss within 90 days of transplantation.

RESULTS

63,182 recipients underwent transplantation; 662 (1.1%) recipients had early hepatic artery thrombosis; of those, 91 (13.8%) had pre-transplant portal vein thrombosis, versus 7.5% with portal vein thrombosis but no hepatic artery thrombosis (p < 0.0001). Portal vein thrombosis was associated with an increased independent risk of hepatic artery thrombosis (OR 2.17, 95% CI 1.71-2.76, p < 0.001) as was donor risk index (OR 2.02, 95% CI 1.65-2.48, p < 0.001). Heparin use at cross clamp, INR, and male donors were all significantly associated with lower risk.

DISCUSSION

Pre-transplant portal vein thrombosis is associated with post-transplant hepatic artery thrombosis independent of other factors. Recipients with portal vein thrombosis might benefit from aggressive coagulation management and careful donor selection. More research is needed to determine causal mechanism.

Vascular complications after adult living donor liver transplantation: Evaluation with ultrasonography

Living donor liver transplantation (LDLT) has been widely used to treat end-stage liver disease with improvement in surgical technology and the application of new immunosuppressants. Vascular complications after liver transplantation remain a major threat to the survival of recipients. LDLT recipients are more likely to develop vascular complications because of their complex vascular reconstruction and the slender vessels. Early diagnosis and treatment are critical for the survival of graft and recipients. As a non-invasive, cost-effective and non-radioactive method with bedside availability, conventional gray-scale and Doppler ultrasonography play important roles in identifying vascular complications in the early postoperative period and during the follow-up. Recently, with the detailed vascular tracing and perfusion visualization, contrast-enhanced ultrasound (CEUS) has significantly improved the diagnosis of postoperative vascular complications. This review focuses on the role of conventional gray-scale ultrasound, Doppler ultrasound and CEUS for early diagnosis of vascular complications after adult LDLT.

Management of early hepatic artery occlusion after liver transplantation with failed rescue

Hepatic artery thrombosis is a serious complication after liver transplantation which often results in biliary complications, early graft loss, and patient death. It is generally thought that early hepatic artery thrombosis without urgent re-vascularization or re-transplantation almost always leads to mortality, especially if the hepatic artery thrombosis occurs within a few days after transplantation. This series presents 3 cases of early hepatic artery thrombosis after living donor liver transplantation, in which surgical or endovascular attempts at arterial re-vascularization failed. Unexpectedly, these 3 patients survived with acceptable graft function after 32 mo, 11 mo, and 4 mo follow-up, respectively. The literatures on factors affecting this devastating complication were reviewed from an anatomical perspective. The collective evidence from survivors indicated that modified nonsurgical management after liver transplantation with failed revascularization may be sufficient to prevent mortality from early hepatic artery occlusion. Re-transplantation may be reserved for selected patients with unrecovered graft function.

Preoperative transarterial chemoembolization does not increase hepatic artery complications after liver transplantation: A single center 12-year experience

BACKGROUND

As a bridge to liver transplantation or downstaging therapy for hepatocellular carcinoma (HCC) patients, preoperative transarterial chemoembolization (TACE) has potential risks in causing damage to hepatic artery (HA), resulting in severe postoperative complications.

AIM

To evaluate the impact of pre-TACE on postoperative hepatic artery complications (HAC) for HCC patients in a single liver transplant center.

MATERIALS AND METHODS

Clinical data of 450 HCC patients undergoing orthotopic liver transplantation (OLT) from January 2001 to December 2013 were retrospectively analyzed. Patients were divided into Group 1 (with pre-TACE) and Group 2 (without pre-TACE). Preoperative characteristics and postoperative HAC were compared.

RESULTS

One hundred and eleven patients (69 men; median age, 37±9.9 years) in Group 1 were compared with 339 patients (244 men; median age, 38.8±8.0 years) in Group 2. Patients were comparable in donor/recipients characteristics between groups. Histological review for native liver samples showed that Edema was the most often seen complication following pre-OLT TACE (troncluar: 87 vs 9; segmental: 91 vs 10; liver parenchyma: 93 vs 8; P=0.000). Fibrosis, thrombosis and aneurysm were only seen in Group 1. There were no significant difference in postoperative HAC (5/111 (4.5%) vs 5/339 (1.5%), P=0.131) between groups.

CONCLUSION

Our single institution experience showed that it might be safe to perform pre-TACE in HCC patients before OLT. It would not increase postoperative HAC risk.

The recipient celiac trunk as an alternative to the native hepatic artery for arterial reconstruction in adult liver transplantation

During liver transplantation (LT), the recipient hepatic artery (RHA) cannot always be used, and alternatives include aortohepatic conduits and the splenic artery (SA). We report our experience with arterial reconstruction on the recipient celiac trunk (RCT), which has rarely been described. Since January 2013, we have been using the RCT when the RHA could not be used. All cases were discussed in a multidisciplinary LT meeting, and arterial patency or anomalies were systemically viewed with computed tomography (CT) scan. The RCT was used after section-ligation of all celiac trunk collaterals. Until May 2014, the RHA could not be used in 11/139 (8%) patients who underwent LT. Postoperative arterial patency was assessed by serial Doppler ultrasound and CT scan. The advantages and disadvantages of the different arterial conduits were evaluated. The RCT was used in 7/11 (64%) patients. Mean follow-up was 10 (6-15) months. The patency rate was 100%, and 1 patient with associated portal shunting died at day 20 from septic complications. No related gastric or splenic complications were encountered. The RCT could not be used in 4 patients with reconstruction on the SA (n = 2), infrarenal (n = 1), and supraceliac aorta (n = 1). The patency rate was 75%. One patient with SA conduit and portal shunting developed pancreatitis/anastomotic pseudoaneurysm with secondary rupture. An emergency infrarenal conduit was created, which was later embolized because of infected pseudoaneurysms. Although the literature reports a higher risk of thrombosis with aortohepatic conduits, no long-term results are available for the SA conduits, and only 1 report is available for the RCT. In conclusion, this study shows that the RCT is a good alternative to the RHA and can be used in two-thirds of patients with inadequate RHA flow.

Diagnosis and Management of Hepatic Artery Complications After Liver Transplantation

BACKGROUND

We assessed the usefulness of color Doppler imaging in diagnosis and monitoring hepatic artery complications after liver transplantation.

METHODS

Subjects were 421 liver transplant recipients who underwent serial ultrasound (US) color Doppler evaluations of the hepatic arteries after surgery.

RESULTS

We saw 4 hepatic arterial complications after liver transplantation (13 thrombosis, 29 stenosis, 2 kinking, 2 pseudo-aneurysm, and 2 pseudo-aneurysm rupture). All subjects underwent US color Doppler examination periodically after surgery. In 6 cases of early thrombosis, hepatic arterial obstruction was diagnosed with absence of Doppler signals; in the other 7 cases (late hepatic artery thrombosis), thrombosis was suspected for the presence of intra-parenchymal "tardus-parvus" waveforms. In all of the cases, computed tomography angiography showed obstruction of the main arterial trunk and the development of compensatory collateral circles (late hepatic artery thrombosis). In 10 of the 29 cases of stenosis, Doppler ultrasonography examination revealed stenotic tract and intra-hepatic tardus-parvus waveforms; in 17 stenosis cases, the site of stenosis could not be identified, but intra-parenchymal tardus-parvus waveforms were recorded. In 2 patients, hepatic artery stenosis occurred with ischemic complications.

CONCLUSIONS

The use of US color Doppler examination allows the early diagnosis of hepatic arterial complications after liver transplantation. Tardus-parvus waveforms indicated severe impairment of hepatic arterial perfusion from either thrombosis or severe stenosis. The presence of these indirect signs enhanced the accuracy of color Doppler diagnosis, and detection should prompt therapy.

Effect of small donor weight and donor-recipient weight ratio on the outcome of liver transplantation in children

A small donor weight is a risk factor for HAT with potential for graft loss. To test this hypothesis, we evaluated outcomes of pediatric liver transplants utilizing donors <20 kg using the UNOS database from 01/2003 to 01/2012 (n = 1311). All isolated liver transplants with whole organ grafts were included. Recipients were divided into four groups based on donor weight: group 1, donor weight <5 kg (n = 34 [2%]); group 2, 5-10 kg (431 [33%]); group 3, 10-15 kg (560 [43%]); and group 4, 15-20 kg (286 [22%]). Actuarial patient survival for the first year post-transplant was significantly lower in groups 1 and 2 compared to groups 3 and 4 (p = 0.002), similarly the one-yr graft function (p < 0.0001). The difference was due to graft loss within the first month for groups 1 and 2. HAT was significantly higher in groups 1 and 2 compared to others (p = 0.0006). Logistic regression analysis demonstrated donor weight as the most predictive factor with analysis of the ROC curve showing a cutoff point at 7.8 kg. The donor-recipient weight ratio did, in none of the models, gain statistical significance.

Impact of hepatic arterial hemodynamics in predicting early hepatic arterial thrombosis in pediatric recipients younger than three yr after living donor liver transplantation

We used Doppler US to evaluate the changes in hepatic arterial hemodynamics that occur following LDLT in pediatric recipients, with a view to assessing the utility of these parameters in predicting early HAT. A retrospective review of 144 pediatric recipients (73 males, 71 females) who underwent routine Doppler US in the first week after LDLT was undertaken, and changes in hepatic arterial hemodynamics were assessed. The HARI and HAPSV were compared in patients with early HAT (defined as occurring in the first postoperative week) and a control group, and the utility of these parameters in predicting early HAT after LDLT was determined. A total of 11 pediatric recipients experienced early HAT, being diagnosed on average four and a half days after LDLT. HARI and HAPSV values were significantly different between the early HAT group and controls. HARI values <0.6 on the day before the onset of early HAT were able to predict HAT development with a sensitivity of 81.8% and specificity of 95.2%. This provides evidence for routine Doppler US examination in these patients and supports consideration of more intensive anticoagulation in these high-risk patients.