Uni- and multi-variate analysis of risk factors for early and late hepatic artery thrombosis after liver transplantation

Median Arcuate Ligament Syndrome (MALS) in Hepato-Pancreato-Biliary Surgery: A Narrative Review and Proposed Management Algorithm

Median arcuate ligament syndrome (MALS) is an uncommon condition characterized by the compression of the celiac trunk by the median arcuate ligament. Due to the anatomical proximity to the foregut, MALS has significant implications in hepato-pancreato-biliary (HPB) surgery. It can pose complications in pancreatoduodenectomy and orthotopic liver transplantation, where the collateral arterial supply from the superior mesenteric artery is often disrupted. The estimated prevalence of MALS in HPB surgery is approximately 10%. Overall, there is consensus for a cautious approach to MALS when embarking on complex foregut surgery, with a low threshold for intraoperative median arcuate ligament release or hepatic artery reconstruction. The role of endovascular intervention in the management of MALS prior to HPB surgery continues to evolve, but more evidence is required to establish its efficacy. Recognizing the existing literature gap concerning optimal management in this population, we describe our tertiary center experience as a clinical algorithm to facilitate decision-making. Research question: What is the significance and management of median arcuate ligament syndrome in patients undergoing hepato-pancreato-biliary surgery?

Intra-arterial lipo-prostaglandin E1 infusion for arterial spasm in liver transplantation: A case report

BACKGROUND

Hepatic artery obstruction is a critical consideration in graft outcomes after living donor liver transplantation. We report a case of diffuse arterial vasospasm that developed immediately after anastomosis and was managed with an intra-arterial infusion of lipo-prostaglandin E1 (PGE1).

CASE SUMMARY

A 57-year-old male with hepatitis B virus-related liver cirrhosis and hepatocellular carcinoma underwent ABO-incompatible living donor liver transplant. The grafted hepatic artery was first anastomosed to the recipient's right hepatic artery stump. However, the arterial pulse immediately weakened. Although a new anastomosis was performed using the right gastroepiploic artery, the patient's arterial pulse rate remained poor. We attempted angiographic intervention immediately after the operation; it showed diffuse arterial vasospasms like 'beads on a string'. We attempted continuous infusion of lipo-PGE1 overnight via an intra-arterial catheter. The next day, arterial flow improved without any spasms or strictures. The patient had no additional arterial complications or related sequelae at the time of writing, 1-year post-liver transplantation.

CONCLUSION

Angiographic evaluation is helpful in cases of repetitive arterial obstruction, and intra-arterial infusion of lipo-PGE1 may be effective in treating diffuse arterial spasms.

Impact of donor age on short-term outcomes after pediatric split liver transplantation

Background

Donor shortage is an important limitation of liver transplantation (LT). Split liver transplantation (SLT) may increase the sources of donors and reduce the problem of organ shortage. However, there are no standard criteria of the selection of SLT donor, especially regarding the donor age.

Methods

We retrospectively analyzed the clinical data of children who received initial SLT between January 2015 and December 2021. Based on the age of donors, the patients were divided into groups A (1-10 years old; n = 26), B (10-45 years old; n = 87), and C (45-55 years old; n = 27). The short-term (<1 year after SLT) outcomes of the recipients were analyzed.

Results

A total of 140 patients received SLT from 122 donors. The 1-, 3- and 12-month patient survival rates in group A were 100.0%, and the graft survival rates were 92.3%. The 1-, 3- and 12-month survival rates of patient and graft in group B were 97.7%, 96.6%, and 95.0%, respectively, and in group C were 85.2%, 85.2%, and 81.1%, respectively. The patient survival rate was significantly lower in group C than in groups A and B (p = 0.0082). There was no significant difference in graft survival between the three groups (p = 0.0545).

Conclusions

Similar results were obtained for pediatric SLT with donors <10 years old and 10-45 years old. Pediatric SLT can be performed with older donors (45-55 years) after strict donor selection and selection of appropriate recipients.

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.

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.

How to Handle Arterial Conduits in Liver Transplantation? Evidence From the First Multicenter Risk Analysis

OBJECTIVE

The aims of the present study were to identify independent risk factors for conduit occlusion, compare outcomes of different AC placement sites, and investigate whether postoperative platelet antiaggregation is protective.

BACKGROUND

Arterial conduits (AC) in liver transplantation (LT) offer an effective rescue option when regular arterial graft revascularization is not feasible. However, the role of the conduit placement site and postoperative antiaggregation is insufficiently answered in the literature.

STUDY DESIGN

This is an international, multicenter cohort study of adult deceased donor LT requiring AC. The study included 14 LT centers and covered the period from January 2007 to December 2016. Primary endpoint was arterial occlusion/patency. Secondary endpoints included intra- and perioperative outcomes and graft and patient survival.

RESULTS

The cohort was composed of 565 LT. Infrarenal aortic placement was performed in 77% of ACs whereas supraceliac placement in 20%. Early occlusion (≤30 days) occurred in 8% of cases. Primary patency was equivalent for supraceliac, infrarenal, and iliac conduits. Multivariate analysis identified donor age >40 years, coronary artery bypass, and no aspirin after LT as independent risk factors for early occlusion. Postoperative antiaggregation regimen differed among centers and was given in 49% of cases. Graft survival was significantly superior for patients receiving aggregation inhibitors after LT.

CONCLUSION

When AC is required for rescue graft revascularization, the conduit placement site seems to be negligible and should follow the surgeon's preference. In this high-risk group, the study supports the concept of postoperative antiaggregation in LT requiring AC.

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.

Early Hepatic Artery Thrombosis After Living Donor Liver Transplant: A 13-Year Single-Center Experience in Jordan

OBJECTIVES

Early hepatic artery thrombosis is a serious complication that may follow living donor liver transplant. Acute graft loss and patient morbidity and mortality are possible consequences. The therapeutic algorithm includes surgical or interventional revascularization, conservative approaches, or retransplantation.

MATERIALS AND METHODS

Among 155 patients who underwent living donor liver transplant at our transplant center from 2004 to 2020, there were 5 who developed hepatic artery thrombosis. From our 13- year experience, we herein present their demographic and clinical characteristics, radiological imaging findings, perioperative courses, and the postoperative follow-up.

RESULTS

All patients displayed advanced liver disease with a Child-Pugh score of C and a mean Model for End-Stage Liver Disease score of 32. Underlying causes for end-stage liver disease included hepatitis B and C infection and cryptogenic liver cirrhosis. The mean patient age was 49 years; 2 patients were female. Living donor liver transplant was performed with donor tissue from immediate kin, according to Jordanian allocation rules. The diagnosis of hepatic artery thrombosis was made by Doppler ultrasonography and confirmed via computed tomography. After surgical revision of the anastomosis, our first patient experienced thrombotic recurrence. All patients received interventional catheterization with local thrombolysis and subsequently developed rethrombosis. Despite prevalent thrombosis, 4 patients achieved long-term survival without further deterioration of liver function. Cumulative 1-year, 5-year, and 10-year survival rates were 80%, 80%, and 60%, respectively. Spontaneous recanalization of the hepatic artery was observed in 1 patient.

CONCLUSIONS

Favorable long-term outcomes are achievable in patients with persistent hepatic artery thrombosis. When retransplant is not feasible and interventional approaches fail, conservative treatment with careful observation of liver function should be implemented. Attentive observation of collateral circulation toward the liver, distal of the thrombosis, may be beneficial to both graft and patient survival.

RISK FACTORS ASSOCIATED WITH HEPATIC ARTERY THROMBOSIS: ANALYSIS OF 1050 LIVER TRANSPLANTS

Background:

Hepatic artery thrombosis is an important cause of graft loss and ischemic biliary complications. The risk factors have been related to technical aspects of arterial anastomosis and non-surgical ones.

Aim:

To evaluate the risk factors for the development of hepatic artery thrombosis.

Methods:

The sample consisted of 1050 cases of liver transplant. A retrospective and cross-sectional study was carried out, and the variables studied in both donor and recipient.

Results:

Univariate analysis indicated that the variables related to hepatic artery thrombosis are: MELD (p=0.04) and warm time ischemia (p=0.005). In the multivariate analysis MELD=14.5 and warm ischemia time =35 min were independent risk factors for hepatic artery thrombosis. In the prevalence ratio test for analysis of the anastomosis as a variable, it was observed that patients with continuous suture had an increase in thrombosis when compared to interrupted suture.

Conclusions:

Prolonged warm ischemia time, calculated MELD and recipient age were independent risk factors for hepatic artery thrombosis after liver transplantation in adults. Transplanted patients with continuous suture had an increase in thrombosis when compared to interrupted suture. Re-transplantation due to hepatic artery thrombosis was associated with higher recipient mortality.

Outcomes of hemi- versus whole liver transplantation in patients from mainland china with high model for end-stage liver disease scores: a matched analysis

Background

Adult hemiliver transplantation (AHLT) is an important approach given the current shortage of donor livers. However, the suitability of AHLT versus adult whole liver transplantation (AWLT) for recipients with high Model for End-Stage Liver Disease (MELD) scores remains controversial.

Methods

We divided patients undergoing AHLT and AWLT into subgroups according to their MELD scores (≥ 30: AHLT, n = 35; AWLT, n = 88; and < 30: AHLT, n = 323; AWLT, n = 323). Patients were matched by demographic data and perioperative conditions according to propensity scores. A cut-off value of 30 for MELD scores was determined by comparing the overall survival data of 735 cases of nontumor liver transplantation.

Results

Among patients with an MELD score ≥ 30 and < 30, AHLT was found to be associated with increased warm ischemia time, operative time, hospitalization time, and intraoperative blood loss compared with AWLT (P < 0.05). In the MELD ≥ 30 group, although the 5-year survival rate was significantly higher for AWLT than for AHLT (P = 0.037), there was no significant difference between AWLT and AHLT in the MELD < 30 group (P = 0.832); however, we did not observe a significant increase in specific complications following AHLT among patients with a high MELD score (≥ 30). Among these patients, the incidence of complications classified as Clavien-Dindo grade III or above was significantly higher in patients undergoing AHLT than in those undergoing AWLT (25.7% vs. 11.4%, P = 0.047). For the MELD < 30 group, there was no significant difference in the incidence of complications classified as Clavien-Dindo grade III or above for patients undergoing AHLT or AWLT.

Conclusion

In patients with an MELD score < 30, AHLT can achieve rates of mortality and overall survival comparable to AWLT. In those with an MELD score ≥ 30, the prognosis and incidence of complications classified as Clavien-Dindo III or above are significantly worse for AHLT than for AWLT; therefore, we may need to be more cautious regarding the conclusion that patients with a high MELD score can safely undergo AHLT.

Imaging post liver transplantation part I: vascular complications

Liver transplantation continues to rise in frequency, with over 1,000 procedures performed in the UK in 2018. Complications are increasingly uncommon but when they occur, early recognition and intervention is vital to save grafts. Imaging after the perioperative period is often performed at patients' local hospitals meaning that all radiologists and sonographers need to have an understanding of how to assess a transplant liver. Part I of this series will focus on vascular complications, including the normal postoperative vascular anatomy following liver transplantation, normal post-transplantation vascular imaging findings and abnormal findings that may prompt further investigation. Vascular complications following liver transplantation will be illustrated using a collection of cases.

Evaluation of implantable Doppler probe continuous monitoring of hepatic artery anastomosis after liver transplantation

Background

Thrombosis of hepatic artery anastomosis (HAT) after liver transplantation is a catastrophic and dreaded complication. Early identification of HAT can salvage the situation. To monitor the anastomosis, conventional daily transcutaneous Doppler is performed. However, it has disadvantages of being noncontinuous, operator-dependent and technically difficult. Implantable Doppler probes wrapped around the anastomosed vessel giving continuous signal may be an important tool; however, very few studies are performed to study its efficacy after intra-abdominal vascular anastomosis, and its role is not clearly established.

Methods

Patients who underwent deceased donor liver transplant surgery were part of the study. On hepatic arterial anastomosis, implantable Doppler probe was fixed for monitoring. Conventional daily transcutaneous Doppler was also performed and the results were compared.

Results

A total of 40 hepatic arterial anastomoses were studied. The incidence of HAT was 10.53%. For the implantable Doppler probe monitoring, sensitivity and negative predictive value was 100%, whereas specificity was 94.44% and positive predictive value was 66.66% with an overall accuracy of 95%. A mean of 10 h of lead time was gained by implantable Doppler probe monitoring.

Conclusion

Our study showed that there was high sensitivity and negative predictive value of implantable Doppler probe monitoring system, which makes it ideal for post-operative vascular anastomoses surveillance monitoring; however, abnormal positive finding on implantable Doppler probe monitoring needs to be confirmed by conventional transcutaneous Doppler. The implantable Doppler probe monitoring, because of its round the clock and continuous nature gives us a good lead time in identifying vascular complication, which translates into graft salvage and reduction in morbidity and mortality.

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.

Donor-to-recipient weight ratio is a risk factor for hepatic artery thrombosis after whole-liver transplantation in children under 25 kg

Hepatic artery thrombosis (HAT) following pediatric liver transplantation increases morbidity and risk of graft failure. We performed a retrospective chart review of all patients who underwent deceased-donor liver transplantation from August 2002 to July 2016. Multi-organ transplant recipients were excluded. We examined the incidence of HAT at our institution and sought to identify associated donor or recipient risk factors. A total of 127 deceased-donor liver transplant patients with a median age of 1.7 years (IQR 0.67-6.7) were identified. Of those, 14 developed HAT, all weighing under 25 kg. Among 100 patients under 25 kg, whole-liver graft recipients had an odds ratio of 3.98 (95% confidence interval [CI]: 1.03, 15.34; P = .045) for developing HAT compared with split-liver graft recipients. Within the whole-liver recipient group under 25 kg, 11 patients developed HAT with a median donor-to-recipient ratio (DRWR) of 0.9 (IQR: 0.7-1.2) compared with a median DRWR of 1.4 (IQR: 1.1-1.9) for those who did not develop HAT. Multivariate analysis showed DRWR to be an independent risk factor for HAT in patients weighing under 25 kg who received whole organ grafts, with an odds ratio of 3.89 (95% CI: 1.43, 10.54; P = .008) for each 0.5 unit decrease in DRWR. Our results suggest that in recipients under 25 kg 1) split-liver grafts may have a lower rate of HAT and 2) selecting whole organ donors with a higher DRWR may decrease the incidence of HAT.

Impact of ABO-incompatibility on hepatic artery thrombosis in living donor liver transplantation

Background

The current era of rituximab-based regimens brought improved survival in ABO-incompatible (ABO-I) living donor liver transplantation (LDLT). Nevertheless, the actual risk for hepatic artery thrombosis (HAT) still remains to be investigated. The aim of this study was to evaluate the impact of ABO-incompatibility on HAT in adult LDLT patients.

Methods

Patients who received ABO-I LDLT were compared to those who received ABO-compatible (ABO-C) LDLT with a special focus on HAT.

Results

A total of 378 patients underwent LDLT from January 2012 to February 2018. Of those, ABO-I LDLT was performed in 78 consecutive patients. The other 300 patients with ABO-C LDLT constituted the comparator group. No significant differences were observed between the two groups in baseline and perioperative characteristics. HAT occurred in 11 (2.9%) patients, 2 and 9 patients in ABO-I and ABO-C LDLT groups, respectively, which didn't show any significant difference between the two groups (P=0.84). All were categorized into early HAT. Immediate revascularization by intraarterial thrombolysis was successfully employed in 8 patients. Surgical revision of anastomosis and retransplantation were performed in 1 and 2 patients, respectively. No one-year mortality was related to HAT in the two groups. The overall outcomes including biliary complications made no significant difference between the two groups.

Conclusions

ABO-incompatibility has no adverse impact on the incidence and treatment outcome of HAT in the current rituximab-based desensitization.

Risk factors of hepatic artery thrombosis in pediatric deceased donor liver transplantation

PURPOSE

Hepatic artery thrombosis (HAT) remains a life-threatening complication in liver transplantation. We aim to investigate the risk factors of HAT in deceased donor pediatric liver transplantation.

METHODS

104 recipients from 2014 to 2016 were enrolled; donor and recipient characteristics, surgical variables, graft and recipient survival rate were compared between recipients with or without HAT. Univariate and multivariate analysis were applied to identify the risk factors of HAT.

RESULTS

The recipient survival rate was 87.0% and 96.3% at 1 year, and 87.0% and 96.3% at 3 years in HAT and non-HAT groups without significant difference. The graft survival rate was 73.9% and 96.3% at 1 year, and 73.9% and 95.1% at 3 years in HAT and non-HAT groups; significant difference was observed between two groups at both 1 and 3 years. Donor age less than 8.5 months, graft weight less than 190 g and GRWR less than 2.2% were identified as independent risk factors for HAT. Recipients with HAT were associated with higher incidence of post-operative biliary complications.

CONCLUSIONS

Young donor age and small liver graft are risk factors for HAT in deceased donor pediatric liver transplantation.

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.

Recipient Selection for Optimal Utilization of Discarded Grafts in Liver Transplantation

BACKGROUND

In France, liver grafts that have been refused by at least 5 teams are considered for rescue allocation (RA), with the choice of the recipient being at the team's discretion. Although this system permits the use of otherwise discarded grafts in a context of organ shortage, outcomes and potential benefits need to be assessed.

METHODS

Between 2011 and 2015, outcomes of RA grafts (n = 33) were compared with SA grafts (n = 321) at a single French center.

RESULTS

Liver grafts in the RA group were older (63 ± 17 years vs 54 ± 18 years, P = 0.007) and had a higher DRI (1.86 ± 0.45 vs 1.61 ± 0.47, P = 0.010). Recipients in this group had a lower Model for End-Stage Liver Disease score (14 ± 5 vs 22 ± 10, P < 0.001) and had mostly hepatocellular carcinoma (67.0% vs 40.4%, P = 0.010). The balance of risk score was significantly lower in the RA group (5.5 ± 2.9 vs 9.2 ± 5.5, P < 0.001). There were higher rates of early and delayed hepatic artery thrombosis (15.2% vs 3.1%, P = 0.001) and retransplantation (18.2% vs 4.7%, P = 0.002) in the RA group. Patient survival was not different between groups, but graft survival was impaired (95% vs 82% at 1 year and 94% vs 74% at 3 years, P = 0.001).

CONCLUSION

Our results show that discarded liver grafts can be used provided that there is a strict recipient selection process, although hepatic artery thrombosis and retransplantation are more frequent. This strategy enables utilization of otherwise discarded grafts in the context of organ shortage.

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 Donor Risk Index on Risk of Hepatic Artery Thrombosis in Patients After Orthotopic Liver Transplantation

BACKGROUND

Hepatic artery thrombosis (HAT) is one of the most severe complications after liver transplantation (LT). HAT can lead to early graft loss and retransplantation or death of the recipient.

METHODS

This retrospective cohort study was conducted using data from patients treated between January 2008 and December 2013 in the Department of General, Transplant and Liver Surgery at the Medical University of Warsaw. A total of 750 patients underwent LT over this period.

RESULTS

HAT occurred in 27 patients (2.1%). The median DRI was 1.414 (IQR 1.103-1.578) points and median donor age was 47 (IQR 33-56) years. The optimal cut-off value of DRI in predicting HAT was ≥1.328 points. The cutoff point was characterized by sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 88.0%, 41.3%, 5.5% and 98.9%, respectively (AUC = 0.605, 95% CI 0.477-0.733). A DRI ≥1.328 was a significant risk factor for HAT (OR = 5.16, 95% confidence interval [CI] 1.529-17.48, P = .008). The optimal cutoff point for donor age was 50 years and was characterized by sensitivity, specificity, PPV, and NPV of 66.7%, 55.8%, 5.3%, and 97.8%, respectively. Donor age ≥50 years (OR = 2.53, 95% CI 1.123-5.714, P = .025) was a significant risk factor for HAT.

CONCLUSION

DRI is a clinically relevant factor that allows estimating the risk of HAT after liver transplantation from a deceased donor. To reduce the incidence of this complication, the allocation of organs taken from donors at DRI exceeding 1.328 for recipients without other HAT risk factors should be considered.

Placement of an Aortohepatic Conduit as an Alternative to Standard Arterial Anastomosis in Liver Transplantation

Background

The aim of this study was to assess the impact of placement of an aortohepatic conduit on graft and patient survival after liver transplantation (LT) in selected patients with an inadequate recipient hepatic artery (HA) for a standard arterial anastomosis.

Material/Methods

Of 331 patients who underwent deceased donor LT, 25 (7.6%) who received placement of an aortohepatic conduit at the time of transplantation were included. Clinical characteristics and outcomes, including postoperative complications, conduit patency, and graft and patient survival rates, were analyzed.

Results

All 25 patients included in this study presented a high preoperative Model for End-stage Liver Disease score (25.4±8.6; range, 6–42) and high rates of retransplantation (n=11, 44%) or previous abdominal – pelvic surgery (n=5, 20%). The observed postoperative vascular complications were portal vein thrombosis in 3 cases (12%) and anastomosis-site bleeding of the aortohepatic conduit in 1 case (4%); there was no HA thrombosis or stenosis in our analysis. With a median follow-up of 37 months (range, 0–69 months), all aortohepatic conduits were patent, and the graft and patient survival rates were 84% and 68%, respectively. The causes of death were graft failure (n=4), pneumonia (n=3), and cerebrovascular accidents (n=1).

Conclusions

Our results indicate that placement of an aortohepatic conduit is a feasible alternative to a standard arterial anastomosis in selected patients whose HA and surrounding potential inflow arteries are not suitable for standard arterial anastomosis.

Liver Retransplantation for Hepatic Abscess Due to Hepatic Artery Thrombosis: A Case Report

INTRODUCTION

Hepatic artery thrombosis (HAT) is a well-recognized complication of liver transplantation (LT). HAT is an important risk factor for infectious, in particular hepatic abscess, which can cause graft loss and increasing morbidity and mortality.

CASE REPORT

We present a case report of complicated LT in a 52-year-old Caucasian man with primary sclerosing cholangitis. In 2007 the patient was included on the waiting list in Padua for LT. In 2012 the patient underwent percutaneous transhepatic biliary drainage for bile duct stricture, complicated with acute pancreatitis. A diagnostic laparoscopy was performed with choledochotomy and Kehr's T tube drainage. On February 14, 2012, the patient underwent LT with arterial reconstruction and choledochojejunostomy. The postoperative course was complicated with HAT, multiple liver abscesses, and sepsis associated with bacteremia due to Enterococcus faecium despite massive intravenous antibiotic therapy and percutaneous drainages. On November 28, 2012, the patient underwent retransplantation. Four years after transplantation the patient is still in good general condition.

CONCLUSION

Hepatic abscess formation secondary to HAT following LT is a major complication associated with important morbidity and mortality. In selected cases retransplantation should be considered as our case demonstrates.

Polymorphisms of the human platelet antigen-1, -2, -3, -5, and -15 systems and acute cellular liver transplant rejection

The human platelet antigen (HPA)-1, -2, -3, -5, and -15 systems are characterized as polymorphic alloantigens expressed on platelets and endothelial cells. In this retrospective study, we investigated, whether HPA-1, -2, -3, -5, and -15 incompatibilities are associated with acute cellular liver transplant rejection. A total of 96 Caucasian liver transplant recipients and corresponding donors were analyzed, 43 with biopsy proven acute cellular rejection (BPAR) and 53 without acute cellular rejection (No-BPAR). Polymorphisms of mentioned HPA systems were determined by polymerase chain reaction-sequence specific primers (PCR-SSP). Our data demonstrate that acute cellular rejection episodes were associated with HPA-3 incompatibility (58% HPA-3 incompatibility in BPAR group vs. 32% HPA-3 incompatibility in No-BPAR group, p=0.013). Furthermore, the frequency of HPA-3bb genotype was significantly higher in BPAR recipients as compared to No-BPAR recipients (30% vs 6%, p=0.002). On the other hand, there was no association between acute cellular rejection and the other tested HPA systems. We conclude that in the Caucasian population the HPA-3 system confers susceptibility to acute cellular rejection after 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.

Abdominal Arterial Anomalies in Children With Alagille Syndrome: Surgical Aspects and Outcomes of Liver Transplantation

OBJECTIVES

Angiogenic defects secondary to gene mutations of JAG1 and NOTCH2, causing arterial anomalies in Alagille syndrome (AGS), are well described in the literature. The study analyzes the frequency of abdominal arterial anomalies in children with AGS with an emphasis on outcomes following liver transplantation (LT).

METHODS

Between 1988 and 2013, 242 children with AGS were treated at our institution. We performed a retrospective analysis of 55 who underwent LT during the study period. Preoperative abdominal arterial findings, operative reports, arterial reconstruction technique, and early as well as late complications following LT were reviewed specifically focusing on arterial thrombosis.

RESULTS

Twenty-five patients had preoperative imaging available for analysis. Twelve of these patients showed celiac trunk stenosis (48.0%), 2, a superior mesenteric artery stenosis (8.0%) and one a stenosis of both renal arteries. Twenty patients (36.3%) underwent standard hepatic reconstruction using the native recipient hepatic artery. Thirty-five patients (63.7%) underwent aortic conduit reconstruction (ACR) from the infrarenal aorta using donor arterial conduits. Hepatic artery thrombosis occurred in 9 patients (16.3%). This number was higher in the standard arterial anastomosis group 7/20 (35.0%) than in those with ACR 2/35 (5.7%, P = 0.0079).

CONCLUSIONS

In this series, children with AGS pretransplant have a high prevalence of abdominal arterial anomalies. Preoperative abdominal vascular imaging makes it possible to anticipate whether or not a classical arterial revascularization can be performed or whether an ACR is required.

Reducing the incidence of hepatic artery thrombosis in pediatric liver transplantation: Effect of microvascular techniques and a customized anticoagulation protocol

We aimed to assess the incidence of HAT over three eras following implementation of microvascular techniques and a customized anticoagulation protocol in a predominantly cadaveric split liver transplant program. We retrospectively reviewed pediatric liver transplants performed between April 1986 and 2016 and analyzed the incidence HAT over three eras. In E1, 1986-2008, each patient received a standard dose of 5 U/kg/h of heparin and coagulation profiles normalized passively. In E2, 2008-2012, microvascular techniques were introduced. In E3, 2012-2016, in addition, a customized anticoagulation protocol was introduced which included replacement of antithrombin 3, protein C and S, and early heparinization. A total of 317 liver transplants were completed during the study period, with a median age of 31.7 months. In E1, 22% of grafts were cadaveric in situ split grafts, while the second and third eras used split grafts in 59.0% and 64.9% of cases, respectively. HAT occurred in 9.5% in the first era, 11.5% (P=.661) in the second, and dropped to 1.8% in the third era (P=.043). A routine anticoagulation protocol has significantly reduced the incidence of HAT post-liver transplantation in children in a predominantly cadaveric in situ split liver transplant program.

Preoperative Thromboelastography as a Sensitive Tool Predicting Those at Risk of Developing Early Hepatic Artery Thrombosis After Adult Liver Transplantation

BACKGROUND

Whilst causes of hepatic artery thrombosis (HAT) after liver transplantation (LT) are multifactorial, early HAT (E-HAT) remains pertinent complication impacting on graft and patient survival. Currently there is no screening tool that would identify patients with increased risk of developing E-HAT.

METHODS

We analyzed the native procoagulant state of LT recipients, identified through pretransplant thromboelastographic (TEG) data among other known risk factors, to identify risk factors for E-HAT.

RESULTS

The outcomes of 828 adult patients undergoing LT between 2008 and 2013 were analyzed. Overall, 79 (9.5%) patients experienced HAT, E-HAT was diagnosed in 23, and in the remainder this was "late" HAT. The maximum amplitude (MA) on preoperative TEG was significantly higher in patients diagnosed with E-HAT compared with those who did not (71.2 mm vs 57.9 mm; P < 0.0001). Receiver operating characteristic analysis with the cutoff value for MA of 65 mm or greater returned area under the curve of 0.750 (P < 0.001) predicting E-HAT with a sensitivity of 70%. A total of 7% of patients with an MA of 65 mm or greater went on to develop E-HAT (hazard ratio, 5.28; 95% confidence interval, 2.10-12.29; P < 0.001), whereas only 1.2% patients with an MA less than 65 mm experienced E-HAT.

CONCLUSIONS

Preoperative TEG may reliably identify group of recipients at greater risk of developing E-HAT, and intense surveillance and anticoagulation prophylaxis may avoid this serious complication after LT.

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.

Diagnosis and outcomes of collateral arterial formation after irreversible early hepatic artery thrombosis in pediatric liver recipients

BACKGROUND

Early hepatic artery thrombosis (eHAT) has been recognized as an important cause of graft loss and mortality. However, the incidence, etiology and outcome are not clear, especially for children. The present study was to investigate the formation of collateral artery flow after irreversible eHAT and its impact on patient's prognosis.

METHODS

We analyzed eHAT after liver transplantation in children from October 2006 to April 2015 in our center, illustrated the formation of collateral hepatic artery flow after irreversible eHAT and explored the diagnosis, complications, treatment and prognosis. The basic and follow-up ultrasonographic images were also compared.

RESULTS

Of the 330 pediatric liver recipients, 22 (6.67%) developed eHAT within 1 month. Revascularization attempts including surgical thrombectomy, interventional radiology and conservational treatment (thrombolysis) were successful in 5 patients. Among the 17 patients who had irreversible eHAT, follow-up ultrasonography revealed that collateral artery flow was developed as early as 2 weeks after eHAT. Liver abscess and bile duct complication occurred secondary to eHAT in variable time.

CONCLUSIONS

Collateral arterial formation is a compensatory adaptation to eHAT to supply blood to liver grafts. However, the severe bile duct damage secondary to eHAT is irreversible and retransplantation is unavoidable.

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.

Dorsal approach plus branch patch technique is the preferred method for liver transplanting small babies with monosegmental grafts

PURPOSE

When living donor liver transplantation (LDLT) is performed on small infant patients, the incidence of hepatic artery complications (HACs) is high. Here, we present a retrospective analysis that focuses on our surgical procedure for hepatic arterial reconstruction and the outcomes of monosegmental LDLT.

METHODS

Of the 275 patients who underwent LDLT between May 2001 and December 2015, 13 patients (4.7 %) underwent monosegmental LDLT. Hepatic artery reconstruction was performed under a microscope. The size discrepancy between the graft and the recipient's abdominal cavity was defined as the graft to recipient distance ratio (GRDR) between the left hepatic vein and the portal vein (PV) bifurcation on a preoperative computed tomography scan. HACs were defined as hepatic arterial hypoperfusion.

RESULTS

Recipient hepatic arteries were selected for the branch patch technique in five cases (38.5 %), and the diameter was 2.2 ± 0.6 mm. The anastomotic approaches selected were the dorsal position of the PV in seven cases (53.8 %) and the ventral position in six, and the GRDRs were 2.8 ± 0.4 and 1.9 ± 0.5, respectively (p = 0.012). The incidence rate of HACs caused by external factors, such as compression or inflammation around the anastomotic site, was significantly higher in monosegmental than in non-monosegmental graft recipients (15.4 vs. 1.1 %, p < 0.001).

CONCLUSION

Although monosegmental graft recipients experienced HACs caused by external factors around the anastomotic field, hepatic arterial reconstruction could be safely performed. Important components of successful hepatic arterial reconstructions include the employment of the branch patch technique and the selection of the dorsal approach.

Resolution of Hepatic Artery Thrombosis in 2 Pediatric Liver Transplant Patients

Hepatic artery thrombosis (HAT) is a serious complication after liver transplantation. This is the first report of spontaneous resolution of HAT in pediatric liver transplant patients on low molecular weight heparin therapy. A total of 2 patients, a 26-month-old boy who presented with acute liver failure and required emergent liver transplantation and a 15-year-old boy with ulcerative colitis and autoimmune hepatitis-primary sclerosing cholangitis overlap underwent liver transplantation for progressive cirrhosis; both developed HAT during the postoperative period. They were both treated with low molecular weight heparin. Follow-up imaging for both patients showed resolution of HAT without evidence of collateral flow.

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.

Late liver function test abnormalities post-adult liver transplantation: a review of the etiology, investigation, and management

Approximately 24,000 liver transplants are performed annually worldwide, almost 7000 of which are performed in the USA. Survival is excellent and continues to improve, with 1-year survival currently exceeding 85 %, but effective management of patients after liver transplantation is critical to achieve optimal results. A plethora of diseases can affect the transplanted allograft, ranging from recurrence of the original disease to de novo liver pathology, and diagnosis can be complicated by nonclassical presentation, de novo disease, or inconclusive histology. Patients can remain asymptomatic despite significant damage to the transplanted liver, so prompt identification and treatment of liver disease after transplantation is crucial to preserve allograft function. Liver function tests are routinely taken throughout the postoperative period to monitor the graft. Although nonspecific, they are inexpensive, noninvasive, and sensitive for allograft disease and can quickly alert physicians to the presence of asymptomatic pathology. This review will outline possible causes of liver function test abnormalities in the late posttransplant period and provide guidance for investigation, diagnosis, and management.

[Vascular reconstruction in visceral transplantation surgery]

Vascular reconstruction is obligatory in transplantation surgery. A differentiation is made between routine vascular reconstructions, which are required for all solid organ transplantations and special cases. Because of the shortage of organs it is often necessary to use organs with complex anatomical vascular prerequisites, which requires high vascular surgical expertise for individualized reconstruction. Non-routine reconstructions are often also necessary on the side of the recipient. This review article presents both the routine and exceptional types of reconstruction.

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.

The effect of Doppler ultrasound on early vascular interventions and clinical outcomes after liver transplantation

BACKGROUND

During the immediate postoperative period after liver transplantation (LT), postoperative bleeding and vascular complications (stenosis, thrombosis) are the two most common complications that require therapeutic decisions. Doppler ultrasound (DUS) is the established method for screening vascular patency after LT during the immediate postoperative period. The objective of our study was to evaluate the impact of DUS performed on postoperative days (POD) 1 and 2 on early vascular interventions.

METHODS

We studied 200 patients who had undergone living donor or deceased donor liver transplantation between January 2011 and March 2012. Postoperative liver DUS findings of up to POD 14, including patency of hepatic artery, portal vein, and hepatic vein, were retrieved. Patients with normal DUS findings on POD 1 and POD 2 were classified as the normal early DUS group. Patients with abnormal DUS findings at POD1 or POD2 were classified as the abnormal early DUS group. Frequency of vascular interventions was compared between the two groups. Risk factors that predict vascular interventions also were assessed.

RESULTS

On POD 1 and 2, 81.5 % (163/200) had normal DUS findings and management was not altered by subsequent DUS findings. Two patients in the normal group were found to have hepatic artery dissection and hepatic vein thrombosis on routine CT on POD 7 and received vascular intervention. DUS results in the two patients were normal until POD 6, but DUS performed after the CT on POD 7 were consistent with the CT findings. Of the 37 recipients who showed abnormal DUS findings on POD 1 or 2, the DUS findings were normalized or unchanged thereafter in 33 patients and no vascular interventions were performed. Two patients underwent hepatic artery thrombectomy on POD 2, one patient required a portal vein thrombectomy on POD 1, and one patient died on POD 3 due to bleeding. The overall incidence of vascular complication requiring vascular interventions was 2.5 %. Logistic regression identified abnormal DUS findings on POD 1 or 2 as an independent risk factor of vascular complications requiring intervention.

CONCLUSIONS

In LT recipients who demonstrate normal DUS findings in the first 2 postoperative days, additional DUS screening may have value only when clinically indicated.

Iatrogenic-related transplant injuries: the role of the interventional radiologist

As advances in surgical techniques and postoperative care continue to improve outcomes, the use of solid organ transplants as a treatment for end-stage organ disease is increasing. With the growing population of transplant patients, there is an increasing need for radiologic diagnosis and minimally invasive procedures for the management of posttransplant complications. Typical complications may be vascular or nonvascular. Vascular complications include arterial stenosis, graft thrombosis, and development of fistulae. Common nonvascular complications consist of leaks, abscess formation, and stricture development. The use of interventional radiology in the management of these problems has led to better graft survival and lower patient morbidity and mortality. An understanding of surgical techniques, postoperative anatomy, radiologic findings, and management options for complications is critical for proficient management of complex transplant cases. This article reviews these factors for kidney, liver, pancreas, islet cell, lung, and small bowel transplants.