Pediatric Orthotopic Liver Transplantation Research Articles

Biliary complications in pediatric liver transplantation: findings of percutaneous transhepatic cholangiography in a large single-center cohort.

Although biliary complications after orthotopic liver transplantation represent a common source of morbidity and mortality, decreasing graft survival, consensus is lacking on their management in the pediatric population. The aim of this study was to present the prevalence of such biliary complications and their interventional radiologic management with representative images. This retrospective study reports our experience with percutaneous transhepatic cholangiography in the management of biliary complications after orthotopic liver transplantation in pediatric patients. This study enrolled all pediatric patients (<18years old) who underwent percutaneous transhepatic cholangiography for the management of biliary complications after orthotopic liver transplantation at a tertiary care center between January 2010 and December 2020. Diagnosis of biliary complications and indication to perform percutaneous transhepatic cholangiography were based on clinical, laboratory or radiologic data. Among the 301 orthotopic liver transplantations, 78 (26%) developed biliary complications that were managed by interventional radiology: these included 52 (17.3%) biliary strictures, 19 (6.3%) bile leaks, 5 (1.7%) biliary stones, 1 (0.3%) iatrogenic biliary obstruction and 1 (0.3%) vanishing syndrome. The median time interval between orthotopic liver transplantation and the diagnosis of biliary complications was 6.0years (interquartile range [IQR] 8.2years). Percutaneous transhepatic cholangiography and biliary duct catheterization were successful in all cases, with low rates of complications that were variable among subgroups. A wide spectrum of biliary complications can occur after pediatric orthotopic liver transplantation. In this large single-center experience, we highlight the value of percutaneous transhepatic cholangiography in their diagnosis and management. Percutaneous treatments in pediatric patients are safe and effective, providing resolution or serving as a bridge to surgery, including re-transplantation.

Arterioportal Fistulas (APFs) in Pediatric Patients: Single Center Experience with Interventional Radiological versus Conservative Management and Clinical Outcomes.

Arterioportal fistulas (APFs) are uncommon vascular abnormalities with a heterogeneous etiology. In pediatric orthotopic liver transplantation (OLT), APFs are frequently iatrogenic, following percutaneous liver interventions. The aim of this study was to report the 10-year experience of a tertiary referral center for pediatric OLT in the interventional radiological (IR) and conservative management of acquired APFs. A retrospective search was performed to retrieve pediatric patients (<18 years old) with a diagnosis of APF at color Doppler ultrasound (CDUS) or computed tomography angiography (CTA) from 2010 to 2020. Criteria for IR treatment were the presence of hemodynamic alterations at CDUS (resistive index <0.5; portal flow reversal) or clinical manifestations (bleeding; portal hypertension). Conservatively managed patients served as a control population. Clinical and imaging follow-up was analyzed. Twenty-three pediatric patients (median age, 4 years; interquartile range = 11 years; 15 males) with 24 APFs were retrieved. Twenty patients were OLT recipients with acquired APFs (16 iatrogenic). Twelve out of twenty-three patients were managed conservatively. The remaining 11 underwent angiography with confirmation of a shunt in 10, who underwent a total of 16 embolization procedures (14 endovascular; 2 transhepatic). Technical success was reached in 12/16 (75%) procedures. Clinical success was achieved in 8/11 (73%) patients; three clinical failures resulted in one death and two OLTs. After a median follow-up time of 42 months (range 1–107), successfully treated patients showed an improvement in hemodynamic parameters at CDUS. Conservatively managed patients showed a stable persistence of the shunts in six cases, spontaneous resolution in four, reduction in one and mild shunt increase in one. In pediatric patients undergoing liver interventions, APFs should be investigated. Although asymptomatic in most cases, IR treatment of APFs should be considered whenever hemodynamic changes are found at CDUS.

1396. Live Virus Vaccination Following Pediatric Liver Transplantation: Results from Two Academic Children’s Hospitals

BackgroundGuidelines for immunization following solid organ transplantation discourage live virus vaccination (LVV) in most recipients. Single-center studies support LVV as safe and effective in orthotopic liver transplant (OLT) recipients on steroid-free immunosuppression (IS). We retrospectively evaluated LVV after OLT at 2 pediatric hospitals.MethodsRecords from OLT recipients between Jan 2007 and Dec 2017 at Lurie Children’s (Chicago) and Children’s Hospital of Philadelphia were reviewed. Patients who underwent OLT at either institution, had ≥ 2 years of follow up, and had documentation of vaccination prior to OLT were included. Adverse events (AEs) within two weeks of receipt of LVV were captured. Factors that might influence the selection of patients for LVV were reviewed, including choice, dose, frequency, and levels of IS medications. IS in non-vaccinated patients was compared to vaccinated patients at two year post-transplant follow-up in both groups using Chi-Square and T-test.ResultsData from 249 patients met inclusion criteria. Varicella zoster (VZV) vaccine was given at least once to 92 patients post-transplant, and MMR to 91 (Table 1). Compared to patients who were re-vaccinated after transplant, those who received their first LVV after OLT were transplanted at a younger age (0.8 v 2.2 years) and received LVV sooner post-OLT (649 v 907 days). AEs were rare for either LVV: 2 experienced injection site reaction, 2 localized rash, and 1 had fever. One recipient experienced worsening rejection one month after MMR and received IV steroids and increased IS, but had no clinical findings concerning for viral infection from vaccination. Most LVV recipients were on a single IS agent both at time of LVV and 2 year post-OLT (Table 2), with tacrolimus the most frequent agent. Compared to those that did not received LVV post-OLT, those that did were on one IS agent more often. Tacrolimus levels were similar among patients receiving LVV post-OLT compared with those who did not.Table 1 Table 2 ConclusionIn a series of pediatric OLT recipients, post-OLT LVV was generally safe and well tolerated. Patients who received LVV post-OLT were more often on one IS agent at 2 year follow up compared to those who did not. Our study supports prospective efforts to define guidelines for patients who may safely receive LVV after OLT.DisclosuresKevin J. Downes, MD, Merck, Inc. (Grant/Research Support)

Standardization of post-operative antimicrobials reduced exposure while maintaining good outcomes in pediatric liver transplant recipients.

Infections following orthotopic liver transplant (OLT) result in significant morbidity and mortality, warranting careful consideration of risks associated with antibiotic overuse and benefits of infection prevention. In the absence of specific guidelines for antimicrobial prophylaxis in pediatric OLT, we developed a standardized approach to post-operative (post-op) antimicrobial therapy including 48hours of antibiotics, no vancomycin for post-op fever within the first 48hours, and caspofungin only for certain situations. The goal was to reduce antimicrobial utilization and adverse outcomes associated with longer duration of and broader treatment while maintaining good outcomes. The impact of this standardization on antimicrobial utilization and clinical outcomes at the largest pediatric liver transplant center in the United States is described. All individuals receiving an OLT from 1/1/17-9/30/17 (N=38) and 3/14/18-12/13/18 (N=27) were included in the pre-intervention (PreI) and post-intervention (PostI) groups, respectively. The intervention resulted in a significant reduction in individuals receiving post-op broad-spectrum gram-negative antibiotics for >48hours (76% PreI vs 44% PostI OLT recipients, P=.01) and post-op vancomycin use (50% PreI, vs 7.4% PostI, P<.001). There were no statistically significant differences between groups for post-op fever, positive pre-/post-operative cultures, receipt of massive transfusion, or hospital length of stay. In conclusion, following the implementation of a standardized approach to post-op prophylaxis, antimicrobial exposure was significantly reduced without affecting OLT recipient outcomes.

Juvenile erythrocytosis in children after liver transplantation: prevalence, risk factors and outcome

Most reports of post-transplant erythrocytosis have involved kidney recipients and, so far, there have been no large studies of onset of erythrocytosis after orthotopic liver transplantation (OLT) in children. We present a long-term survey of pediatric liver recipients, evaluating prevalence, outcome and the main potential causes of erythrocytosis, including a comprehensive mutational analysis of commonly related genes (mutations of HBB and HBA, JAK2, EPOR, VHL, EPAS1 and EGLN1). Between 2000 and 2015, 90 pediatric OLT recipients were observed for a median period of 8.7 years (range 1–20.4 [IQR 4.9–13.6] years). Five percent of the study population (4 males and 1 female) developed erythrocytosis at 8.5 years post OLT (range 4.1–14.9 [IQR 4.7–14.7]) at a median age of 16.6 years (range 8.2–18.8 [IQR 11.7–17.7]). Erythrocytosis-free survival after OLT was 98.6% at 5 years, 95% at 10 years, and 85% at 15 years, with an incidence rate of 6/1000 person-years. No cardiovascular events or thrombosis were reported. No germinal mutation could be clearly related to the development of erythrocytosis. One patient, with high erythropoietin levels and acquired multiple bilateral renal cysts, developed clinical hyper-viscosity symptoms, and was treated with serial phlebotomies. In conclusion, this prospective longitudinal study showed that erythrocytosis is a rare complication occurring several years after OLT, typically during adolescence. Erythrocytosis was non-progressive and manageable. Its pathogenesis is still not completely understood, although male gender, pubertal age, and renal cysts probably play a role.

Predictors of Immediate Tracheal Extubation in the Operating Room After Pediatric Liver Transplantation.

Pediatric orthotopic liver transplant recipients frequently need mechanical ventilation during the immediate posttransplant period. However, intensive care unit beds are costly and scarce; therefore, anticipating which patients will require postoperative mechanical ventilation support is important. In addition, immediate postoperative extubation may reduce the incidence of postoperative respiratory complications and improve patient outcomes after orthotopic liver transplant. Here, we aimed to determine the predictors of need for mechanical ventilation after orthotopic liver transplant in pediatric patients. We retrospectively analyzed the records of 57 pediatric patients who underwent orthotopic liver transplant (performed by the same team at Baskent University Hospital from April 1996 to August 2009). Patients were divided into 2 groups according to whether they required postoperative mechanical ventilation or not. Collected data included demographic features; comorbidities; cause of liver failure; perioperative laboratory values; intraoperative hemodynamic parameters; use and volume of crystalloids, colloids, and blood products; albumin levels; portal vein clamping time, requirement of inotropes/vasopressors; and anesthesia duration. Mean age and body weight of patients were 25.0 ± 23.1 months and 10.8 ± 5.3 kg, respectively. Of 57 patients, 26 (46%) needed postoperative mechanical ventilation. Compared with those who did not require postoperative mechanical ventilation, patients who required mechanical ventilation had growth failure (P = .03), higher mean intraoperative lactate level (P = .03), and higher mean intraoperative fresh frozen plasma/erythrocyte suspension (P = .049) and intraoperative vasopressor (P = .022) requirements. Multivariate logistic regression analysis revealed that growth failure (odds ratio = 37; P = .03) and higher intraoperative lactate level (odds ratio = 1.5; P = .03) were predictors of the need for mechanical ventilation. About 46% of our pediatric orthotopic liver transplant recipients required mechanical ventilation postoperatively. Growth failure and higher intraoperative lactate levels were associated with need for postoperative mechanical ventilation.

Abstract No. 648 Balloon angioplasty without metallic stenting for treatment of pediatric liver transplant postoperative venous anastomotic stenosis: long-term results

To describe our long-term experience using balloon angioplasty for treatment of portal and venous anastomotic stenosis in pediatric orthotopic liver transplant (OLT) patients without concomitant use of metal stents. With IRB approval, we retrospectively reviewed our pediatric OLT database for patients with significant venous anastomotic stenosis requiring treatment. Parameters analyzed included age at time of initial angioplasty, time from OLT to stenosis treatment. primary patency rate, time to stenosis recurrence, and long-term follow-up. Nineteen patients (12 female) underwent 37 angioplasty procedures. Eight patients had more than one OLT. In all patients, angioplasty was performed on their last liver. Mean age at first angioplasty was 6.3 years. Technical success was 100%. Treatment sites consisted of portal vein (13), IVC (5), mesocaval shunt (1). In the 12 patients (63%) requiring only one angioplasty, long-term patency post angioplasty was observed throughout their follow-up period (mean follow-up, 8 years; range, 1–18.3 years). Seven patients (37%) received more than one angioplasty. For those undergoing more than one angioplasty the mean interval between treatments was 18.8 months (median, 10.1 mo, range, 2 weeks-18 years). On long-term follow-up, 4 patients expired, unrelated to the procedure. Time from last treatment to time of death was 10.2 years, 8.6 years, 2.3 years and 0.1 years, respectively. Balloon angioplasty is an effective and durable method for the treatment of portal and venous anastomotic stenosis in pediatric liver transplant patients, avoiding use of metallic stents in growing children.

Staged Biliary Reconstruction After Orthotopic Liver Transplantation: A Practical Surgical Strategy for High-Acuity Adult Recipients.

Background.Biliary complications (BC) following orthotopic liver transplantation (OLT) is strongly associated with inferior patient outcomes and increased healthcare cost. BC in high-acuity patients can be lethal. While the utility of staged biliary reconstruction after liver transplantation (SBRALT) has been reported in adult and pediatric OLT, biliary outcome data are scarce. We sought to evaluate the clinical utility and outcomes of SBRALT in high-acuity transplant recipients.Methods.We conducted an analysis from our prospective database of 149 adult OLT between January 1, 2012, and September 30, 2017. Mean follow-up was 26 months. Variables were compared for Group I: one-stage OLT with biliary reconstruction (N = 58) versus Group II: SBRALT (N = 91).Results.Compared with Group I, patients in Group II had higher acuity of illness: median model for end-stage liver disease scores (19 vs 35 P = 0.002), requirement for pretransplant intensive care unit (29.3% vs 54.9%, P = 0.022), pretransplant renal replacement therapy (15.5% vs 48.4%), estimated blood loss (2000 vs 4750 mL, P < 0.001), and intraoperative packed red blood cells transfusion (4 vs 10 units, P < 0.001). For Group II, biliary reconstruction was performed between 1 and 6 days after OLT. Hepaticojejunostomy was performed in 8.6% (Group I) and 26.4% (Group II), P = 0.010. For Groups I and II, BC rates (8.6% vs 7.7%, P = 0.955) and 1-year graft failure-free survival rates (89.7% vs 88.2%, P = 0.845) were comparable.Conclusions.Graft failure-free survival and biliary outcomes of SBRALT in high-acuity recipients are excellent and comparable to one-stage OLT for low-risk patients. SBRALT is a practical surgical strategy in complex OLT.

P186 Antibody-mediated rejection following pediatric orthotopic liver transplant: a single center experience

P186 Antibody-mediated rejection following pediatric orthotopic liver transplant: a single center experience

Recanalization of Chronic Portal Vein Occlusion in Pediatric Liver Transplant Patients

PurposeTo evaluate technical and clinical success and report long-term outcomes of portal vein (PV) recanalization in pediatric orthotopic liver transplant (OLT) patients with chronic PV occlusion. Materials and MethodsThis is a retrospective review of 15 OLT patients (5 males) with chronic PV occlusion who underwent PV recanalization (33 procedures) between October 2011 and February 2018. Median age was 4.5 years (range, 1–16 years); median weight was 16.6 kg (range, 11.5–57.3 kg). Median time interval from OLT to first intervention was 3.25 years (range, 0.6–15.7 years). Clinical presentations included hypersplenism (n = 12), gastrointestinal bleeding (n = 9), and ascites (n = 3). One patient had incidental diagnosis of PV occlusion. Primary, primary-assisted, and secondary patency at 3, 6, 12, and 24 months were evaluated. ResultsTechnically successful PV recanalization and reduction of PV pressure gradient to ≤ 5 mm Hg was performed in 13/15 patients (87%). Ten of 15 (67%) patients had successful recanalization with the first attempt. Clinical success, defined as improvement in signs and symptoms of portal hypertension, was achieved in 12/13 (92%) patients. Five of 33 (15%) major complications (Society of Interventional Radiology class C), including perisplenic hematoma (n = 2), hemoperitoneum (n = 2), and hepatic artery pseudo aneurysm (n = 1), were managed with pain medication and blood product replacement. Median follow-up was 22 months (range, 1–77 months). Median primary patency was 5 months. Primary patency at 3, 6, 12, and 24 months was 53.8%, 46.2%, 38.5%, and 30.8%, respectively. Primary-assisted patency was 84.6%, 76.9%, 53.8%, and 46.2%, respectively. Secondary patency was 92.3%, 84.6%, 53.8%, and 46.2%, respectively. ConclusionsPV recanalization is a safe and effective minimally invasive option in the management of chronic PV occlusion after pediatric OLT.

Staged biliary reconstruction after liver transplantation: A novel surgical strategy for high acuity pediatric transplant recipients

IntroductionBiliary complications after pediatric orthotopic liver transplantation remain causes of significant patient morbidity. Staged operative approach in complex hepatobiliary surgery has improved postoperative outcomes but has not been evaluated in pediatric orthotopic liver transplantation. We sought to analyze the outcomes of staged biliary reconstruction after orthotopic liver transplantation in high acuity patients. MethodsA retrospective analysis of 43 pediatric orthotopic liver transplantations at our center (January 2013 through December 2017). Median follow-up was 25 months. Variables were compared for group I: 1-stage orthotopic liver transplantation with biliary anastomosis (n = 6) versus group II: staged biliary reconstruction orthotopic liver transplantation (n = 37). ResultsComparing groups I and II, median age (7.3 vs 4.8 years), weight (27 vs 19 kg), proportion of urgent orthotopic liver transplantation (50% vs 65%), partial graft orthotopic liver transplantation (33% vs 35%), and intraoperative red blood cell transfusion volume (11 vs 21 mL/kg) were comparable. Roux-en-Y hepaticojejunostomy was performed in 67% (group I) and 49% (group II). There was no biliary complication in both groups. For groups I and II, 3-year survival rates for graft (100% vs 92%, P = .477) and patient (100% vs 97%, P = .679) were comparable. ConclusionOur study showed excellent outcomes with staged biliary reconstruction orthotopic liver transplantation in high acuity pediatric transplant recipients. This is the first report showing clinical applicability of staged biliary reconstruction orthotopic liver transplantation in children.

No Child Left Behind: Liver Transplantation in Critically Ill Children

Advances in critical care prolong survival in children with liver failure, allowing more critically ill children to undergo orthotopic liver transplantation (OLT). In order to justify the use of a scarce donor resource and avoid futile transplants, we sought to determine survival in children who undergo OLT while receiving pre-OLT critical care. We analyzed 13,723 pediatric OLTs using the United Network for Organ Sharing (UNOS) database from 1987 to 2015, including 6,746 recipients in the Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease (MELD/PELD) era (2002 to 2015). There were 1,816 recipients (26.9%) admitted to the ICU at the time of transplantation. We also analyzed 354 pediatric OLT recipients at our center from 2002 to 2015, one of the largest institutional experiences. Sixty-five recipients (18.3%) were admitted to the ICU at the time of transplantation. Kaplan-Meier, volume threshold, and multivariable analyses were performed. Patient survival improved steadily over the study period, (66% 1-year survival in 1987 vs 92% in 2015; p < 0.001). Our institutional experience of ICU recipients in the MELD/PELD era had acceptable outcomes (87% 1-year survival), even among our sickest recipients with vasoactive medications, mechanical ventilation, dialysis, and molecular adsorbent recirculating system requirements. Volume analysis revealed inferior outcomes (hazard ratio [HR] 1.68; 95% CI 1.11 to 2.51) in low-volume centers (<5 annual cases). Identifiable risk factors (previous transplantation, elevated serum sodium, hemodialysis, mechanical ventilation, body weight < 6 kg, and low center volume) increased risk of mortality. This analysis demonstrates that the use of advanced critical care in children and infants with liver failure is justified because OLT can be performed on the sickest children and acceptable outcomes achieved. It is an appropriate use of a scarce donor allograft in a child who would otherwise succumb to a terminal liver disease.

Factors Associated with Postoperative Prolonged Mechanical Ventilation in Pediatric Liver Transplant Recipients.

Introduction Almost all pediatric orthotopic liver transplant (OLT) recipients require mechanical ventilation in the early postoperative period. Prolonged postoperative mechanical ventilation (PPMV) may be a marker of severe disease and may be associated with morbidity and mortality. We determined the incidence and risk factors for PPMV in children who underwent OLT. Methods This was a retrospective analysis of data collected on 128 pediatric OLT recipients. PPMV was defined as postoperative ventilation ≥ 4 days. Perioperative characteristics were compared between cases and control groups. Multivariable logistic regression analysis was used to calculate odds ratios for PPMV after controlling for relevant cofactors. Results An estimated 25% (95% CI, 17.4%–32.6%) required PPMV. The overall incidence of PPMV varied significantly by age group with the highest incidence among infants. PPMV was associated with higher postoperative mortality (p = 0.004) and longer intensive care unit (p < 0.001) and hospital length of stay (p < 0.001). Multivariable analysis identified young patient age, preoperative hypocalcemia, and increasing duration of surgery as independent predictors of PPMV following OLT. Conclusion The incidence of PPMV is high and it was associated with prolonged ICU and hospital LOS and higher posttransplant mortality. Surgery duration appears to be the only modifiable predictor of PPMV.

Sa2071 Small Bowel Balloon Enteroscopy as a Treatment Modality for Retained Biliary Stents after Pediatric Orthotopic Liver Transplantation

Sa2071 Small Bowel Balloon Enteroscopy as a Treatment Modality for Retained Biliary Stents after Pediatric Orthotopic Liver Transplantation

Pediatric Liver Transplantation Across the ABO Blood Group Barrier: Is It an Obstacle in the Modern Era?

The initial experience with ABO incompatible (ABOi) orthotopic liver transplantations (OLTs) was dismal. In the current study, we investigated whether ABOi pediatric OLTs could achieve acceptable patient outcomes. The option for ABOi transplantation is vital because critically ill children have limited access to donor liver allografts. Kaplan-Meier and multivariate Cox analysis was performed on data collected from 13,179 pediatric OLT recipients in the United Network for Organ Sharing database, including 540 ABOi recipients. We also analyzed 18 pediatric recipients of ABOi OLTs at Texas Children's Hospital. Recipients were divided into 2 groups: transplanted between 1987 to 2002 (remote era) and 2002 to 2013 (modern era). Analysis revealed 4 main points. First, there was a significant (p < 0.01) improvement in ABOi OLT survival in the modern era. Second, threshold analysis revealed superior outcomes (p < 0.01) for OLT recipients younger than 2 years of age. Third, survival outcomes for ABOi and ABO-identical OLTs were the same for recipients younger than 2 years: ABOi was 91.8% (1 year) and 88.4% (5 year), and ABO identical was 91.5% (1 year) and 86.7% (5 year) (p= 0.94). Lastly, we found identical OLT results when analyzing our own institutional experience. To date, there has been a 92.9% survival rate in the modern era compared with 75% in the remote era. All recipients younger than 2 years (n= 9) are still alive, compared with 78% of those older than 2 years. This analysis revealed a significant improvement in the survival of ABOi liver transplant recipients in the modern era. Importantly, ABOi liver transplantation can be performed inrecipients younger than 2 years of age with equivalent outcomes compared with ABO-identical recipients.

Expanded Efficacy and Indication of Extracorporeal Membrane Oxygenation for Preoperative Pulmonary Bleeding on Pediatric Cadaveric Orthotopic Liver Transplantation

Expanded Efficacy and Indication of Extracorporeal Membrane Oxygenation for Preoperative Pulmonary Bleeding on Pediatric Cadaveric Orthotopic Liver Transplantation

Epstein‐barr DNA serology and positron‐emission tomography imaging of the head and neck in pediatric transplant recipients

Epstein-Barr virus (EBV) infection is a potential precursor of post-transplantation lymphoproliferative disorder (PTLD) in the pediatric transplant patient. Positron-emission tomography (PET) imaging is increasingly utilized in this population to monitor for neoplasia and PTLD. We assess the association between EBV serum titers and Waldeyer's ring and cervical lymph node PET positivity in the pediatric transplant recipient. Retrospective analysis of EBV serology and PET imaging results in pediatric orthotopic liver transplantation (OLT) recipients. Imaging results and laboratory data were reviewed for all pediatric OLT recipients from January 2005 to July 2011 at a single institution. Charts were evaluated for PET positivity at Waldeyer's ring or cervical lymphatics, and for EBV serology results. Demographic data extracted include patient sex and age at transplantation. A total of 122 pediatric OLT recipients were reviewed. Twelve patients (10%) underwent PET imaging. Overall, four patients (33%) had evidence of PET positivity at Waldeyer's ring or cervical lymphatics. Five patients (42%) had positive EBV serology. There was a significant association between PET imaging results and EBV DNA serology results (P = .01). PTLD surveillance in the pediatric transplant recipient is an important component of long-term care in this population. Although PET imaging is a new modality in monitoring pediatric transplant recipients for early signs of PTLD, an association between EBV serology and PET imaging results appears to exist. With increased implementation, PET imaging will likely prove valuable in its ability to monitor the transplant recipient at risk for PTLD.

998

Introduction: Orthotopic liver transplantation (OLT) patients requiring renal replacement therapy (RRT) generally experience worse outcomes. The purpose of this study is to identify outcomes and survival predictors among pediatric OLT patients receiving perioperative RRT in the pediatric intensive care unit (PICU) and to identify predictors of successful RRT termination. Methods: An IRB-approved retrospective review of our hospital's pediatric patients (0-21 years of age) between January 1, 2000 and December 31, 2011 was conducted. Categorical associations with survival status were tested for statistical significance using Fisher's exact test. Continuous variables were compared between survival status using the Wilcoxon rank sum test or unpaired t-test as appropriate. A Kaplan-Meier curve was constructed to estimate survival rates over time. A mixed model was used to test for differences in urine output. A P-value <0.05 was considered statistically significant. Results: Seventeen patients received RRT within a perioperative OLT period (mean age, 9.23 years; range, 2 months-19 years). Mean BSA was 0.95 m2 (range, 0.14-1.95 m2). Survivors were older at the time of RRT (mean, 11.8 years v. 3 years, P=0.004) and had a higher BSA than non-survivors (mean, 1.18 years v. 0.40 years, P<0.01). Dialysis included intermittent and continuous modalities. Higher urine output during the last 24 hours of RRT was associated with successful RRT termination (mean, 1.36 mL/kg/h v. 0.47 mL/kg/h, P=0.002). Neither calculated glomerular filtration rate at PICU admission nor prior to starting RRT was associated with survival. Twelve patients (70%) survived to hospital discharge with one receiving a renal transplantation. One required dialysis after discharge. Survival from RRT initiation was 82% at 3 months, 76% at 6 months, 71% at one year and 65% at three years. Conclusions: Among pediatric OLT patients receiving perioperative RRT in the PICU, older age is associated with survival, and urine output during the last 24 hours of RRT predicts successful RRT termination. This study supports the use of RRT in pediatric perioperative OLT patients and may help guide patient selection and timing of RRT termination.

Potassium Supplementation Requirement Post Orthotopic Liver Transplantation in Children

Electrolyte disturbances, particularly hypokalemia, are a potentially underreported phenomenon among the over 500 pediatric orthotopic liver transplantations (OLTs) performed annually in the United States. Differing from the reported adult hyperkalemia during OLT, intraoperative hypokalemia has been documented in pediatric patients; however, biomedical literature reporting on the occurrence of postoperative potassium disturbances is lacking. The maintenance of potassium homeostasis is crucial to a patient’s cardiac, neuromuscular, and renal functions; alterations to potassium homeostasis may complicate their postoperative course. The goals of the study were to investigate and quantify the degree of potassium supplementation required in patients with postoperative hypokalemia and to determine whether pediatric post OLT patients possessed altered potassium needs. This retrospective study analyzed serum potassium concentrations and potassium supplementation within the pediatric OLT patients who had procedures performed between 1985-2011 at Mayo Clinic in Rochester, MN. Postoperative data from a sample size of 60 patients was examined by chart review and compared to the patient’s own baseline. Postoperative hypokalemia was noted in approximately 50% of patients within the first three postoperative days. Due to this hypokalemic state, patients required 0.5 m Eq/kg/day of potassium supplementation on average. The highest incidence of decreased serum potassium occurred within the first 72 hours post-transplantation. Age less than one year and use of diuretics were the identified variables associated with increased incidence of potassium supplementation. In conclusion, potassium supplementation is necessary in pediatric patients post OLT due to the high incidence of hypokalemia. Anticipatory and sufficient potassium supplementation in the initial postoperative period may be warranted, especially in infants. Further studies are needed to determine the etiology of this finding and its impact on morbidity and mortality in this patient population.

Predictors of Immediate Tracheal Extubation in the Operating Room after Pediatric Liver Transplantation

Introduction: Pediatric orthotopic liver transplant (OLT) recipients frequently need mechanical ventilation during the immediate posttransplant period. However, intensive care unit beds are costly and scarce, and therefore it is important to anticipate the patients who will require postoperative mechanical ventilation support. In addition immediate postoperative extubation may reduce the incidence of postoperative respiratory complications and improve patient outcome after OLT. In this study we aimed to determine the predictors of mechanical ventilation need after OLT in pediatric patients. Methods: The records of 57 pediatric patients who underwent OLT, performed by the same team in the Baskent University Hospital from April 1990 to August 2009, were retrospectively analyzed. The patients were divided into two groups according to whether they required postoperative mechanical ventilation or not. Collected data included demographic features, co-morbidities, etiology of the liver failure, perioperative laboratory values, intraoperative hemodynamic parameters, use and volume of crystalloids, colloids, blood products and albumin, portal vein clamping time, requirement of inotropes, vasopressors, and duration of anesthesia. Results: The mean age and body weight of the patients were 25.0±23.1 months and 10.8±5.3 kg, respectively. Out of 57 patients, 26 (46%) needed postoperative mechanical ventilation. Compared with those who did not require postoperative mechanical ventilation those who did had growth failure (P=.03), higher mean intraoperative lactate level (P=.03), higher mean intraoperative fresh frozen plasma and erythrocyte suspension requirement per kg (P=.049), and intraoperative vasopressor requirement (P=.022). Multivariate logistic regression analysis revealed that growth failure (odds ratio, 37; P=.03) and a higher intraoperative lactate level (odds ratio, 1.5; P=.03) were predictors of mechanical ventilation need in these patients. Conclusion: 46% of our pediatric OLT recipients required mechanical ventilation postoperatively. Growth failure and higher intraoperative lactate levels were associated with postoperative mechanical ventilation need in our patients.