Antithrombotic management and thrombosis rates in children post-liver transplantation: A case series and literature review

Ten-year follow-up of cavoportal hemitransposition in pediatric liver transplantation for complete portomesenteric venous thrombosis: A case report and literature review

BACKGROUND

Portal vein thrombosis is a potentially devastating complication following pediatric liver transplantation. In rare instances of complete portomesenteric thrombosis, cavoportal hemitransposition may provide graft inflow. Here we describe long-term results following a case of pediatric cavoportal hemitransposition during liver transplantation and review the current pediatric literature.

METHODS

A 9-month-old female with a history of biliary atresia and failed Kasai portoenterostomy underwent living donor liver transplantation, which was complicated by portomesenteric venous thrombosis. The patient underwent retransplantation with cavoportal hemitransposition on postoperative day 12.

OUTCOME

The patient recovered without further complication, and 10 years later, she continues to do well, with normal graft function and no clinical sequelae of portal hypertension. CT scan with 3-D vascular reconstruction demonstrated recanalization of the splanchnic system, with systemic drainage to the inferior vena cava via an inferior mesenteric vein shunt. The cavoportal anastomosis remains patent with hepatopetal flow. Of the 12 previously reported cases of pediatric cavoportal hemitransposition as portal inflow in liver transplantation, this is the longest-known follow-up with a viable allograft. Notably, sequelae of portal hypertension were also rare in the 12 previously reported cases, with no cases of long-term renal dysfunction, lower extremity edema, or ascites.

CONCLUSIONS

Long-term survival beyond 10 years with normal graft function is feasible following pediatric cavoportal hemitransposition. Complications related to portal hypertension were generally short-lived, likely due to the development of robust collateral circulation. Additional reports of long-term outcomes are necessary to facilitate informed decision making when considering pediatric cavoportal hemitransposition for liver graft inflow.

Hepatic artery thrombosis and use of anticoagulants and antiplatelet agents in pediatric liver transplantation

BACKGROUND

Hepatic artery thrombosis (HAT) is a reported complication of 5%-10% of pediatric liver transplantations, rates 3-4 times that seen in adults. Early HAT (seen within 14 days after transplant) can lead to severe allograft damage and possible urgent re-transplantation. In this report, we present our analysis of HAT in pediatric liver transplant from a national clinical database and examine the association of HAT with anticoagulant or antiplatelet medication administered in the post-operative period.

METHODS

Data were obtained from the Pediatric Health Information System database maintained by the Children's Hospital Association. For each liver transplant recipient identified in a 10-year period, diagnosis, demographic, and medication data were collected and analyzed.

RESULTS

Our findings showed an average rate of HAT of 6.3% across 31 centers. Anticoagulant and antiplatelet medication strategies varied distinctly among and even within centers, likely due to the fact there are no consensus guidelines. Notably, in centers with similar medication usage, HAT rates continue to vary. At the patient level, use of aspirin within the first 72 h of transplantation was associated with a decreased risk of HAT, consistent with other reports in the literature.

CONCLUSION

We suggest that concerted efforts to standardize anticoagulation approaches in pediatric liver transplant may be of benefit in the prevention of HAT. A prospective multi-institutional study of regimen-possibly including aspirin-following transplantation could have significant value.

Practice patterns in the management of pediatric iliofemoral arterial thrombosis

BACKGROUND

Acute arterial thrombosis can be life- and limb-threatening. Most pediatric patients with iliofemoral arterial thrombosis are treated successfully with medical therapy; however, expert consensus is limited, and many recommendations are based on the extrapolation of adult data. We aim to understand treatment patterns and long-term outcomes after pediatric acute iliofemoral arterial thrombosis, from which management recommendations can be informed.

METHODS

A single-institution retrospective study of pediatric patients diagnosed with iliofemoral arterial thrombosis from 2009 to 2018 was performed. Multiple parameters of management and follow-up were evaluated. Children anticoagulated for ≤28 days versus >28 days were compared. Data analysis used Fisher exact and Mann-Whitney U tests.

RESULTS

Two hundred thirty-six children were included. Median age at diagnosis was 65 days (interquartile range 17-163), with 207 diagnosed as infants, 15 diagnosed between 1 to 2 years, and 14 diagnosed between 2 to 16 years. The median treatment duration was 28 days (interquartile range 13-42); patients treated for >28 days had a longer time for thrombus resolution, and more follow-up ultrasounds were performed. Limb length discrepancy did not differ between the groups (1.0% vs 6.3%, P = .06), and no patients were documented to have developed peripheral arterial disease over a median 6.5-year follow-up. Multiple treatment strategies were employed, the most common being heparin bridged to enoxaparin (25.0%) and enoxaparin monotherapy (21.6%). Eight patients (3.4%) underwent surgical intervention.

CONCLUSION

Pediatric iliofemoral arterial thrombosis is primarily a disease of infants treated adequately with heparin or enoxaparin, infrequently requires surgical intervention, and is rarely associated with long-term complications. When guided by thrombus resolution on ultrasound, a four-week or shorter course of anticoagulation does not increase the need for surgical intervention or long-term complications.

Impact of patent foramen ovale on short-term outcomes in children with biliary atresia undergoing living donor liver transplantation: a retrospective cohort study

OBJECTIVE

To investigate the impact of patent foramen ovale (PFO) on the short-term outcomes of living donor liver transplantation (LDLT) in children with biliary atresia.

METHODS

With the approval of the hospital ethics committee, 304 children with biliary atresia who underwent LDLT in our center from January 2020 to December 2021 were enrolled. According to the results of echocardiography before the operation, the subjects were divided into the PFO group (n = 73) and the NoPFO group (n = 231). The baseline characteristics; intraoperative recipient-related data and donor-related data; incidence of postreperfusion syndrome (PRS); postoperative mechanical ventilation time; ICU stay duration; postoperative hospital stay duration; liver function index; incidences of postoperative complications including acute renal injury (AKI), graft dysfunction, hepatic artery thrombosis (HAT) and portal vein thrombosis (PVT); and one-year survival rate were compared between the two groups.

RESULTS

The median age in the PFO group was 6 months and that in the NoPFO group was 9 months (P < 0.001), and the median height (65 cm) and weight (6.5 kg) in the PFO group were significantly lower than those in the NoPFO group (68 cm, 8.0 kg) (P < 0.001). The preoperative total bilirubin level (247 vs. 202 umol/L, P = 0.007) and pediatric end-stage liver disease (PELD) score (21 vs. 16, P = 0.001) in the PFO group were higher than those in the NoPFO group. There were no significant differences in the intraoperative PRS incidence (46.6% vs. 42.4%, P = 0.533 ), postoperative mechanical ventilation time (184 vs. 220 min, P = 0.533), ICU stay duration (3.0 vs. 2.5 d, P = 0.267), postoperative hospital stay duration (22 vs. 21 d, P = 0.138), AKI incidence (19.2% vs. 24.7%, P = 0.333), graft dysfunction incidence (11.0% vs. 12.6%, P = 0.716), HAT incidence (5.5% vs. 4.8%, P = 0.762), PVT incidence (2.7% vs. 2.2%, P = 0.675) or one-year survival rate (94.5% vs. 95.7%, P = 0.929) between the two groups.

CONCLUSION

The presence of PFO has no negative impact on short-term outcomes in children with biliary atresia after LDLT.

Treatments and outcomes of intra-operative portal vein thrombosis in living-donor liver transplantation due to biliary atresia

BACKGROUND

Pediatric living-donor liver transplantation (LDLT) has become one of the most effective therapies for pediatric end-stage liver diseases. We aim to investigate the risk factors for intra-operative portal vein thrombosis (PVT) and the short- and long-term outcomes in children post LDLT.

METHODS

This was a retrospective analysis from 584 cases of biliary atresia (BA) patients who had undergone LDLT from January 2014 to December 2019 at our hospital. Patients were divided into PVT and non-PVT groups according to the occurrence of PVT during LDLT.

RESULTS

The median age of recipients at transplantation was 7.22 (quartiles, 6.03, 9.50) months, the incidence of intra-operative PVT was 5.31% (31/584). The independent risk factors for intra-operative PVT were the diameter of the recipient's PV not greater than 4 mm and a higher ratio of graft-to-recipient PV diameter. The cumulative survival rates of grafts and recipients were 93.5% and 93.5% in the PVT group, and 94.9% and 95.3% in the non-PVT group, respectively, without significant difference. The recovery of graft function was similar in recipients with or without interposed graft vessel (IGV). However, the incidence of PV stenosis was higher in recipients with IGV after LDLT.

CONCLUSION

Intra-operative PVT is a common complication in pediatric LDLT, but an excellent prognosis can be achieved by appropriate and individualized surgical treatment. We noted that intra-operative PVT did not affect the survival rates of grafts and recipients, but there was a higher incidence of PV complications after LDLT.

LEVEL OF EVIDENCE

Ⅲ.

Antithrombin supplementation for prevention of vascular thrombosis after pediatric liver transplantation

AIMS

After liver transplantation (LT), synthesis of coagulation factors by the graft recovers faster for pro thrombotic than anti thrombotic factors, resulting in a potential pro thrombotic imbalance. We studied the thrombotic and hemorrhagic complications in our pediatric LT series, providing supplementation of fresh frozen plasma (FFP) and/or antithrombin (AT) in the prophylactic antithrombotic regimen.

METHODS

This was a retrospective observational single center study. All isolated pediatric LTs performed between 1/11/2009 and 31/12/2019 (n = 181) were included. Postoperatively, in addition to low molecular weight heparin, 22 patients (12%) received FFP (10 ml/kg twice daily for 10 days), 27 patients (15%) were given FFP (reduced duration) and AT (50-100 IU/kg/day if AT activity remained <70%), and 132 (73%) received AT only. Complications, outcome, and coagulation profiles in postoperative days 0-10 were analyzed.

RESULTS

In all three treatment groups, AT activity normalized by day 4 while prothrombin remained <70% of normal until day 9. Hepatic artery thrombosis (HAT), portal vein thrombosis (PVT), and hemorrhagic complications occurred in 2.8%, 3.3%, and 3.9% of LTs. One- and 5-year patient and graft survival were 88% (±2.4% Standard Error) and 84% (±2.5%), and 86% (±2.6%) and 84% (±2.7%), respectively, without difference between groups. HAT were associated with low AT on days 0 and 1, and PVT with low AT on day 0.

CONCLUSIONS

Low antithrombin activity after LT was associated with postoperative thromboses. FFP and/or AT supplementation allowed early normalization of AT activity, while thrombotic or hemorrhagic complications were rare, suggesting efficient and safe management of post-LT coagulopathy.

Early thrombotic and hemorrhagic complications associated with a risk-adjusted postoperative anticoagulation protocol after pediatric liver transplantation

BACKGROUND

Systemic anticoagulation after pediatric liver transplantation (pLT) is believed to reduce the incidence of vascular thrombosis, but it may also cause an increase in hemorrhagic complications.

PROCEDURE

A 5-year retrospective review of pLT done at our institution was performed (2014-2018). The occurrence of early hemorrhagic and thrombotic complications was compared when using low-dose or high-dose anticoagulation after transplant (p < .05 considered significant).

RESULTS

Sixty-nine patients received 73 transplants during the study period. Median age at transplant was 2.3 years (40 days to 18.5 years). Low-dose anticoagulation was utilized in 71% cases. Additionally, six patients were converted from low-dose to high-dose anticoagulation because of a thrombotic event or concerns for suboptimal vascular inflow. Postoperative anticoagulation was discontinued in 18 occurrences due to bleeding (low dose 19%, high dose 47% vs. low dose to high dose 17%, p = .085). Surgical take back for bleeding occurred in 17 occasions (low dose 13.5%, high dose 53% vs. low dose to high dose 33%, p = .005). The overall incidence of hepatic artery thrombosis (HAT) and portal vein thrombosis were each 5.5%, respectively. While patient survival was not statistically different between groups, graft survival was significantly lower in the high-dose group (low dose 93%, high dose 73% vs. low dose to high dose 100%, p = .046). However, graft losses from HAT were similar between groups (low dose 2%, high dose 7% vs. low dose to high dose 0%, p = .56).

CONCLUSION

The use of a standardized risk-adjusted anticoagulation protocol after pLT is associated with a low occurrence of thrombotic and hemorrhagic complications. High-dose anticoagulation leads to more bleeding, but those risks outweigh the risks of possible graft loss.

LncRNA Snhg1 Plays an Important Role via Sequestering rno-miR-139-5p to Function as a ceRNA in Acute Rejection After Rat Liver Transplantation Based on the Bioinformatics Analysis

In order to explore the molecular mechanism of acute rejection after liver transplantation (ARLT) in rats, we employed the GSE36798 data set in the Gene Expression Omnibust (GEO) database to construct a related ceRNA network. This dataset contained a total of 16 samples (8 graft samples and 8 plasma samples). Each kind of sample was divided into acute rejection (AR) groups and non-acute rejection (NR) groups, and each group had 4 replicates. First, we performed principal component analysis (PCA) with downloaded data to compare the difference between samples in a macroscopic way. Then, we used the “limma” R package to screen out differentially expressed miRNAs among different groups and used the “pheatmap” R package to perform bidirectional hierarchical clustering analysis for these differentially expressed miRNAs. The miRWalk database and the LncBase V.2 database were applied to predict downstream target genes and upstream-related lncRNAs, respectively. Meanwhile, the String database was used to predict the relationship between target genes, and the aforementioned results were processed for visualization by Cytoscape software. In addition, we exhibited the ultimate ceRNA network, including two lncRNAs, two miRNAs, and 77 mRNAs. Finally, we constructed a rat model of ARLT and applied graft specimens to relevant experimental verification. We found that the lncRNA Snhg1/rno-miR-139-5p axis might be involved in the regulation of ARLT in rats. In short, we demonstrated the differentially expressed miRNA profile, constructed a related ceRNA network, and screened out a possible regulatory axis. In view of the conservation of genes among species, this work was expected to provide a new strategy for the treatment and prevention of ARLT in the clinical setting.

Pediatric Liver Transplantation: Long-Term Follow-Up Issues

Pediatric liver transplant is an established life-saving procedure for children with end-stage liver diseases, achieving excellent graft and patient survival but with effects on quality of life and psychological welfare in the long-term. With the natural increase in the number of pediatric transplant patients becoming adults, it is essential to successfully plan and manage issues affecting late outcomes in the vulnerable pediatric transplant population. This study offers an overview of the long-term surgical complications, the consequences of immunosuppression (such as posttransplant diabetes, hypertension, cardiovascular disease, and renal dysfunction), and the infection and malignancy risks. Finally, because quality of life is now an inclusive measurement of patient satisfaction, guidance on how to facilitate the transition to adulthood, empowering transplant recipients, is also provided.

Hepatic artery reconstruction using an operating microscope in pediatric liver transplantation-Is it worth the effort?

INTRODUCTION

In pediatric liver transplantation (pLT), hepatic artery thrombosis (HAT) is associated with inferior transplant outcome. Hepatic artery reconstruction (HAR) using an operating microscope (OM) is considered to reduce the incidence of HAT.

METHODS

HAR using an OM was compared to a historic cohort using surgical loupes (SL) in pLT performed between 2009 and 2020. Primary endpoint was the occurrence of HAT. Secondary endpoints were 1-year patient and graft survival determined by Kaplan-Meier analysis and complications. Multivariate analysis was used to identify independent risk factors for HAT and adverse events.

RESULTS

A total of 79 pLTs were performed [30 (38.0%) living donations; 49 (62.0%) postmortem donations] divided into 23 (29.1%) segment 2/3, 32 (40.5%) left lobe, 4 (5.1%) extended right lobe, and 20 (25.3%) full-size grafts. One-year patient and graft survival were both 95.2% in the OM group versus 86.2% and 77.8% in the SL group (p = .276 and p = .077). HAT rate was 0% in the OM group versus 24.1% in the SL group (p = .013). One-year patient and graft survival were 64.3% and 35.7% in patient with HAT, compared to 93.9% and 92.8% in patients with no HAT (both p < .001). Multivariate analysis revealed HAR with SL (p = .022) and deceased donor liver transplantation (DDLT) (p = .014) as independent risk factors for HAT. The occurrence of HAT was independently associated with the need for retransplantation (p < .001) and biliary leakage (p = .045).

CONCLUSION

In pLT, the use of an OM is significantly associated to reduce HAT rate, biliary complications, and graft loss and outweighs the disadvantages of delayed arterial perfusion and prolonged warm ischemia time (WIT).

Association of Plasma Fibrinogen Levels on Postoperative Day 1 with 2-Year Survival of Orthotopic Liver Transplantation for HBV-Related HCC

OBJECTIVE

To clarify the prognostic values of hemostatic parameters to predict the survival of patients undergoing orthotopic liver transplantation (OLT) for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC).

METHODS

The data of 182 consecutive adult patients who underwent OLT for HBV-related HCC were subjected to univariate and multivariate analyses.

RESULTS

Ascites and fibrinogen levels on postoperative day (POD) 1 were independent predictors of postoperative 2-year mortality (both P <.05). Kaplan-Meier survival analysis showed that the higher the fibrinogen level on POD 1, the better the 1- and 2-year survival of patients with ascites (P <.05), whereas the fibrinogen level on POD 1 was associated with 1-year (P <.05) but not 2-year survival of patients without ascites.

CONCLUSION

Fibrinogen on POD 1 is a predictor of 2-year post-OLT survival of patients with HBV-related HCC with ascites.

Liver Transplantation in Children: An Overview of Organ Allocation and Surgical Management

Liver transplantation is the standard treatment for children with end-stage liver disease, primary hepatic neoplasms, or liver-localized metabolic defects. Perioperative mortality is almost absent, and long-term survival exceeds 90%. Organ shortage is managed thanks to advances in organ retrieval techniques; living donation and partial liver transplantation almost eliminated waiting list mortality, thus leading to expanding indications for transplantation. The success of pediatric liver transplantation depends on the prompt and early referral of patients to transplant Centers and on the close and integrated multidisciplinary collaboration between pediatricians, hepatologists, surgeons, intensivists, oncologists, pathologists, coordinating nurses, psychologists, and social workers.