Peri-operative Anticoagulation Strategies, Bleeding and Thrombotic Complications in Pediatric Patients Undergoing Intervention for Congenital Portosystemic Shunts.

BACKGROUND: Congenital portosystemic shunts (CPSS) are rare congenital abnormalities causing abnormal blood flow between the portal vein and systemic circulation. This study reports on the peri-operative anticoagulation management of CPSS patients post closure, focusing on the incidence of thrombotic and bleeding complications. METHODS: This is a single-center retrospective analysis of CPSS patients who underwent surgery or endovascular intervention between 2005 and 2021. The protocol included unfractionated heparin (UFH) during and immediately after surgery, followed by either warfarin or low molecular weight heparin (LMWH) postoperatively. Outcomes assessed included postoperative thrombotic and bleeding complications. RESULTS: A total of 44 patients were included. Postoperatively, 89% received treatment-dose UFH, transitioning to warfarin or LMWH at discharge. Thrombotic complications occurred in 16% of patients, predominantly in the superior mesenteric vein. Surgical interventions and continuous infusion of tissue plasminogen activator (tPA) were used for clot resolution. Bleeding complications were observed in 64% of patients, primarily managed with transfusions and temporary UFH interruption. No deaths related to thrombotic, or bleeding events were reported. CONCLUSIONS: Our findings underscore the delicate balance required in anticoagulation management for CPSS patients, revealing an occurrence of both thrombotic and bleeding complications postoperatively. LEVELS OF EVIDENCE: Level II, retrospective study.

A History of Umbilical Vein Catheterization Does Not Preclude Children from a Successful Meso-Rex Bypass.

INTRODUCTION: Umbilical vein catheterization (UVC) can cause portal venous thrombosis, leading to the development of extrahepatic portal venous obstruction (EHPVO) and portal hypertension (PHT). The feasibility of the Meso-Rex bypass (MRB) for the treatment of EHPVO in patients with a history of UVC has been questioned. We compared the feasibility of performing an MRB in patients with or without a history of previous UVC. METHODS: A retrospective review of patients with EHPVO and known UVC status explored for a possible MRB at our institution was performed (1997-2022). Patients were categorized in two groups: with (UVC(+)) or without (UVC(-)) a history of UVC for comparison. A p-value less than 0.05 was considered significant. RESULTS: One hundred and eighty-seven patients were included (n = 57 in UVC(+); n = 130 in UVC(-)). Patients in the UVC group were significantly younger at surgery and the incidence of prematurity was higher. Other risk factors for the development of EHPVO were similar between the groups, but only history of UVC could predict the ability to receive MRB (odds ratio [OR]: 7.4 [3.5-15.4]; p < 0.001). The success rate of MRB was significantly higher in patients with no history of UVC (28/57 [49.1%] in UVC(+) vs. 114/130 [87.7%] in UVC(-); p < 0.001). However, MRB patency at discharge (25/28 [89.3%] in UVC(+) vs. 106/114 [94.7%] in UVC(-); p = 0.3) was equally high in both groups. CONCLUSION: Our results indicate that a history of UVC is not a contraindication to MRB. Half of the patients were able to successfully receive an MRB. Patients with symptomatic PHT from EHPVO should not be excluded from consideration for MRB based on UVC history.

Outcomes after ABO incompatible pediatric liver transplantation are comparable to ABO identical/compatible transplant.

Background: ABO incompatible (ABOi) liver transplantation (LT) was initially associated with a higher incidence of vascular, biliary, and rejection complications and a lower survival than ABO compatible (ABOc) LT. Various protocols have been proposed to manage anti-isohemagglutinin antibodies and hyperacute rejection. We present our experience with a simplified protocol using only plasmapheresis. Methods: A retrospective review of all patients who received an ABOi LT at our institution was performed. Comparisons were made based on era (early: 1997-2008, modern: 2009-2020) and severity of disease (status 1 vs. exception PELD at transplant). A pair-matched comparison was done to patients who received an ABOc LT. p < 0.05 was considered significant. Results: 17 patients received 18 ABOi LT (3 retransplants). Median age at transplant was 7.4 months (1.1-28.9). 66.7% patients were listed as status 1. Hepatic artery thrombosis (HAT) occurred in one patient (5.6%), there were 2 cases of portal vein thrombosis (PVT) (11.1%), and 2 biliary strictures (11.1%). Patient and graft survival improved in the ABOi modern era, although not significantly. In the pair-matched comparison, complications (HAT p = 0.29; PVT p = 0.37; biliary complications p = 0.15) and survival rates were similar. Patient and graft survivals were 100% in the non-status 1 ABOi patients compared to 67% (p = 0.11) and 58% (p = 0.081) respectively for patients who were transplanted as status 1. Conclusion: ABO incompatible liver transplants in infants with a high PELD score have excellent outcomes. Indications for ABO incompatible transplants should be liberalized to prevent deaths on the waiting list or deterioration of children with high PELD scores.

Fluid balance in pediatric postoperative liver transplant recipients.

BACKGROUND: Positive fluid balance (FB) is associated with poor outcomes in critically ill children but has not been studied in pediatric liver transplant (LT) recipients. Our goal is to investigate the relationship between postoperative FB and outcomes in pediatric LT recipients. METHODS: We performed a retrospective cohort study of first-time pediatric LT recipients at a quaternary care children's hospital. Patients were stratified into three groups based on their FB in the first 72 h postoperatively: <10%, 10-20%, and > 20%. Outcomes were pediatric intensive care unit (PICU) and hospital length of stay, ventilator-free days (VFD) at 28 days, day 3 severe acute kidney injury, and postoperative complications. Multivariate analyses were adjusted for age, preoperative admission status, and Pediatric Risk of Mortality (PRISM)-III score. RESULTS: We included 129 patients with median PRISM-III score of 9 (interquartile range, IQR 7-15) and calculated Pediatric End-stage Liver Disease score of 15 (IQR 2-23). A total of 37 patients (28.7%) had 10-20% FB, and 26 (20.2%) had >20% FB. Greater than 20% FB was associated with an increased likelihood of an additional PICU day (adjusted incident rate ratio [aIRR] 1.62, 95% CI: 1.18-2.24), an additional hospital day (aIRR 1.39, 95% CI: 1.10-1.77), and lower likelihood of a VFD at 28 days (aIRR 0.85, 95% CI: 0.74-0.97). There were no differences between groups in the likelihood of postoperative complications. CONCLUSIONS: In pediatric LT recipients, >20% FB at 72 h postoperatively is associated with increased morbidities, independent of age and severity of illness. Additional studies are needed to explore the impact of fluid management strategies on outcomes.

Identification of Early Clinical and Histological Factors Predictive of Kasai Portoenterostomy Failure.

Background: It is impossible to predict which patients with biliary atresia (BA) will fail after Kasai portoenterostomy (KPE). We evaluated the predictive nature of pre-KPE clinical and histological factors on transplant-free survival (TFS) and jaundice clearance. Methods: A retrospective review of patients who received a KPE at our institution (1997−2018) was performed. Primary outcomes were two-year TFS, five-year TFS, and jaundice clearance 3 months after KPE. p < 0.05 was considered significant. Results: Fifty-four patients were included in this study. The two-year TFS was 35.1%, five-year TFS was 24.5%, and 37% patients reached a direct bilirubin (DB) ≤ 2.0 mg/dL 3 months post KPE. The median age at biopsy was younger in the five-year TFS (39.0 (24.5−55.5) vs. 56.0 days (51.0−67.0), p = 0.011). Patients with DB ≤ 1.0 mg/dL 3 months after KPE were statistically younger at biopsy (DB ≤ 1.0 44.0 (26.0−56.0) vs. DB > 1.0 56.0 days (51.0−69.0), p = 0.016). Ductal plate malformation was less frequent in the five-year TFS (16/17, 94.1%, vs. 1/17, 5.9%, p = 0.037). Portal fibrosis (19/23, 82.6%, vs. 4/23, 17.4%, p = 0.028) and acute cholangitis (6/7, 85.7%, vs. 1/7, 14.3%, p = 0.047) occurred less frequently in two-year TFS. Conclusion: Older age at biopsy, acute cholangitis, portal fibrosis, and ductal plate malformation were associated with lower native liver survival. Evaluation in a larger study population is needed to validate these results.

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.

Primary Liver Transplantation vs. Transplant after Kasai Portoenterostomy for Infants with Biliary Atresia.

Introduction: Primary liver transplants (pLT) in patients with biliary atresia (BA) are infrequent, since most babies with BA undergo a prior Kasai portoenterostomy (KPE). This study compared transplant outcomes in children with BA with or without a prior KPE. We hypothesized that pLT have less morbidity and better outcomes compared to those done after a failed KPE. Methods: A retrospective review of patients with BA transplanted at our institution was performed. Patients were included if they received a pLT or if they were transplanted less than 2 years from KPE. Outcomes were compared between those groups. Comparisons were also made based on era (early: 1997−2008 vs. modern: 2009−2020). p < 0.05 was considered significant. Results: Patients who received a pLT were older at diagnosis (141.5 ± 46.0 vs. KPE 67.1 ± 25.5 days, p < 0.001). The time between diagnosis and listing for transplant was shorter in the pLT group (44.5 ± 44.7 vs. KPE 140.8 ± 102.8 days, p < 0.001). In the modern era, the calculated PELD score for the pLT was significantly higher (23 ± 8 vs. KPE 16 ± 8, p = 0.022). Two waitlist deaths occurred in the KPE group (none in pLT, p = 0.14). Both the duration of transplant surgery and transfusion requirements were similar in both groups. There was a significant improvement in graft survival in transplants after KPE between eras (early era 84.3% vs. modern era 97.8%, p = 0.025). The 1-year patient and graft survival after pLT was 100%. Conclusions: Patient and graft survival after pLT are comparable to transplants after a failed KPE but pLT avoids a prior intervention. There was no significant difference in pre- or peri-transplant morbidity between groups other than wait list mortality. A multicenter collaboration with more patients may help demonstrate the potential benefits of pLT in patients predicted to have early failure of KPE.