Metastatic pulmonary calcifications after pediatric liver transplantation.

BACKGROUND: Pulmonary calcification (PC) is a rare clinical entity observed following liver transplantation (LT). Most often identified in adults or in patients with concomitant renal failure, PC is rarely reported in children. While the clinical course of PC is largely benign, cases of progressive respiratory failure and death have been reported. Additionally, PC may mimic several other disease processes making diagnosis and management challenging. Currently, little is reported regarding the diagnosis, management, and long-term outcomes of children with PC following LT. METHODS: We performed a retrospective chart review of patients undergoing LT at our institution between 2006 and 2023. We identified two patients who developed PC following LT. Their diagnosis, clinical course, and long-term outcomes are reported. A literature review of the presentation, diagnosis, management, and outcomes of adult and pediatric patients with PC post-LT was also performed. CONCLUSIONS: Pulmonary calcifications are a rare but notable complication after pediatric liver transplantation. Our case series adds to the limited literature on this clinical entity in children but also highlights the fact that effective diagnosis and treatment may be safely accomplished without the use of lung biopsy.

Immediate extubation after pediatric liver transplantation: Update on a single-center experience.

PURPOSE: Immediate extubation (IE) following liver transplantation (LT) is increasingly common in adult patients. This study reviews our center's experience with IE in children following LT to determine characteristics predictive of successful IE and its effects on post-operative outcomes. METHODS: We performed a retrospective chart review of all patients who underwent LT at our institution between January 2005 and November 2022. Patients with concomitant lung transplants and chronic ventilator requirements were excluded. RESULTS: Overall, 235 patients met study criteria. IE was achieved in 164 (69.8%) patients across all diagnoses and graft types. Of IE patients, only two required re-intubation within 3 days post-transplant. IE patients exhibited significantly shorter ICU (2 [1, 3 IQR] vs. 4 [2, 4 IQR] days, p < .001) and hospital lengths of stay (17 [12, 24 IQR] vs. 22 [14, 42 IQR] days, p = .001). Pre-transplant ICU requirement, high PELD/MELD score, intraoperative transfusion, cold ischemia time, and pressor requirements were risk factors against IE. There was no association between IE and recipient age or weight. The proportion of patients undergoing IE post-transplant increased significantly over time from 2005 to 2022 (p < .001), underscoring the role of clinical experience and transplant team learning curve. CONCLUSION: Spanning 18 years and 235 patients, we report the largest cohort of children undergoing IE following LT. Our findings support that IE is safe across ages and clinical scenarios. As our center gained experience, the rate of IE increased from 40% to 83%. These trends were associated with lower ICU and LOS, the benefits of which include earlier patient mobility and improved resource utilization.

Host-derived oxidized phospholipids initiate effector-triggered immunity fostering lethality upon microbial encounter.

Macrophages detect invading microorganisms via pattern recognition receptors that recognize pathogen-associated molecular patterns, or via sensing the activity of virulence factors that initiates effector-triggered immunity (ETI). Tissue damage that follows pathogen encounter leads to the release of host-derived factors that participate to inflammation. How these self-derived molecules are sensed by macrophages and their impact on immunity remain poorly understood. Here we demonstrate that, in mice and humans, host-derived oxidized phospholipids (oxPLs) are formed upon microbial encounter. oxPL blockade restricts inflammation and prevents the death of the host, without affecting pathogen burden. Mechanistically, oxPLs bind and inhibit AKT, a master regulator of immunity and metabolism. AKT inhibition potentiates the methionine cycle, and epigenetically dampens Il10, a pluripotent anti-inflammatory cytokine. Overall, we found that host-derived inflammatory cues act as "self" virulence factors that initiate ETI and that their activity can be targeted to protect the host against excessive inflammation upon microbial encounter.

Innate immune cellular therapeutics in transplantation.

Successful organ transplantation provides an opportunity to extend the lives of patients with end-stage organ failure. Selectively suppressing the donor-specific alloimmune response, however, remains challenging without the continuous use of non-specific immunosuppressive medications, which have multiple adverse effects including elevated risks of infection, chronic kidney injury, cardiovascular disease, and cancer. Efforts to promote allograft tolerance have focused on manipulating the adaptive immune response, but long-term allograft survival rates remain disappointing. In recent years, the innate immune system has become an attractive therapeutic target for the prevention and treatment of transplant organ rejection. Indeed, contemporary studies demonstrate that innate immune cells participate in both the initial alloimmune response and chronic allograft rejection and undergo non-permanent functional reprogramming in a phenomenon termed "trained immunity." Several types of innate immune cells are currently under investigation as potential therapeutics in transplantation, including myeloid-derived suppressor cells, dendritic cells, regulatory macrophages, natural killer cells, and innate lymphoid cells. In this review, we discuss the features and functions of these cell types, with a focus on their role in the alloimmune response. We examine their potential application as therapeutics to prevent or treat allograft rejection, as well as challenges in their clinical translation and future directions for investigation.

Critical elements of pediatric liver cancer surgery.

The appropriate management of pediatric liver malignancies, primarily hepatoblastoma and hepatocellular carcinoma, requires an in depth understanding of contemporary preoperative risk stratification, experience with advanced hepatobiliary surgery, and a good relationship with one's local or regional liver transplant center. While chemotherapy regimens have become more effective, operative indications more well-defined, and overall survival improved, the complexity of liver surgery in small children provides ample opportunity for protocol violation, inadequate resection, and iatrogenic morbidity. These guidelines represent the distillation of contemporary literature and expert opinion as a means to provide a framework for preoperative planning and intraoperative decision-making for the pediatric surgeon.

Pediatric Organ Donation and Transplantation: Across the Care Continuum.

This policy statement aims to enhance comfort and increase knowledge of pediatric organ donation and transplantation to the general pediatric community, specifically focusing on the pediatric health care professional and the medical home. The pediatric health care professional will care for neonates, infants, children, and adolescents who may become donors or transplant recipients and, thus, is a crucial member of the pediatric patient's care team. Understanding donation, transplantation, and follow-up care are important to primary care engagement. Furthermore, the pediatric health care professional may play a role in shaping public policies related to the process of organ donation and access to organ transplantation.

Intragraft B cell differentiation during the development of tolerance to kidney allografts is associated with a regulatory B cell signature revealed by single cell transcriptomics.

Mouse kidney allografts are spontaneously accepted in select, fully mismatched donor-recipient strain combinations, like DBA/2J to C57BL/6 (B6), by natural tolerance. We previously showed accepted renal grafts form aggregates containing various immune cells within 2 weeks posttransplant, referred to as regulatory T cell-rich organized lymphoid structures, which are a novel regulatory tertiary lymphoid organ. To characterize the cells within T cell-rich organized lymphoid structures, we performed single-cell RNA sequencing on CD45+ sorted cells from accepted and rejected renal grafts from 1-week to 6-months posttransplant. Analysis of single-cell RNA sequencing data revealed a shifting from a T cell-dominant to a B cell-rich population by 6 months with an increased regulatory B cell signature. Furthermore, B cells were a greater proportion of the early infiltrating cells in accepted vs rejecting grafts. Flow cytometry of B cells at 20 weeks posttransplant revealed T cell, immunoglobulin domain and mucin domain-1+ B cells, potentially implicating a regulatory role in the maintenance of allograft tolerance. Lastly, B cell trajectory analysis revealed intragraft differentiation from precursor B cells to memory B cells in accepted allografts. In summary, we show a shifting T cell- to B cell-rich environment and a differential cellular pattern among accepted vs rejecting kidney allografts, possibly implicating B cells in the maintenance of kidney allograft acceptance.

Adjuvant conditioning induces an immunosuppressive milieu that delays alloislet rejection through the expansion of myeloid-derived suppressor cells.

Advances in immunosuppression have been relatively stagnant over the past 2 decades, and transplant recipients continue to experience long-term morbidity associated with immunosuppression regimens. Strategies to reduce or eliminate the dosage of immunosuppression medications are needed. We discovered a novel administration strategy using the classic adjuvant alum to condition murine islet transplant recipients, known as adjuvant conditioning (AC), to expand both polymorphonuclear and monocytic myeloid-derived suppressive cells (MDSCs) in vivo. These AC MDSCs potently suppress T cell proliferation when cultured together in vitro. AC MDSCs also facilitate naïve CD4+ T cells to differentiate into regulatory T cells. In addition, we were able to demonstrate a significant delay in alloislet rejection compared with that by saline-treated control following adjuvant treatment in a MDSC-dependent manner. Furthermore, AC MDSCs produce significantly more interleukin (IL)-10 than saline-treated controls, which we demonstrated to be critical for the increased T cell suppressor function of AC MDSCs as well as the observed protective effect of AC against alloislet rejection. Our data suggest that adjuvant-related therapeutics designed to expand MDSCs could be a useful strategy to prevent transplant rejection and curb the use of toxic immunosuppressive regimens currently used in transplant patients.

Outcomes of internal biliary diversion using cholecystocolostomy for patients with severe Alagille syndrome.

Alagille syndrome (AGS) is a disorder that leads to increased serum cholesterol and bile acids, which can result in debilitating xanthomas and pruritus. External biliary drainage and transplantation are effective treatments for AGS. Internal biliary diversion with Roux-en-Y cholecystocolostomy has been described for other biliary conditions, but not AGS. Three patients with severe pruritus due to AGS underwent Roux-en-Y cholecystocolostomy for internal biliary drainage. Retrospective analysis compared preoperative and post-operative lab values and symptom scores (0, none-4, severe). Three patients underwent cholecystocolostomy. All patients had at least three diagnostic criteria for AGS. Mean preoperative pruritus score was 3.33 (range, 2-4) and mean post-operative score was 1. Mean preoperative xanthoma score was 1.33 (range, 0-4) and post-operative score was 1 at 2-month follow-up. Roux-en-Y cholecystocolostomy can be considered for AGS, which is refractory to medical management. This procedure accomplishes internal biliary diversion without significant physiologic derangements.

Organ allocation in pediatric abdominal transplant.

Pediatric patients constitute an important group within the general transplant population, given the opportunity to significantly extend their lives with successful transplantation. Children have historically received special consideration under the various abdominal solid organ allocation algorithms, but matching patients with size and weight restrictions with appropriate donors remains an ongoing issue. Here, we describe the historical trends in pediatric organ allocation policies for liver, kidney, intestine, and pancreas transplantation. We also review recent changes to these allocation policies, with particular attention to recent amendments to geographical prioritization, with the dissolution of donor service areas and United Network for Organ Sharing (UNOS) regions and the subsequent creation of acuity circles.

Functional side-to-side splenorenal shunts to treat extrahepatic portal vein thrombosis in children.

BACKGROUND: Surgical shunts are commonly used to manage complications resulting from extrahepatic portal vein thrombosis (EHPVT) in children. We describe a single-center experience utilizing a functional Side-to-Side Splenorenal Shunt (fSRS), created using either an enlarged inferior mesenteric vein (IMV) or left adrenal vein (LAV). METHODS: Pediatric patients with isolated EHPVT who were poor candidates for a Rex shunt and who underwent a fSRS procedure at our institution between 2003 and 2020 were reviewed. The pre/post shunt portosystemic gradient change, rates of early and late complications, postoperative shunt patency, and mortality were evaluated. RESULTS: Twelve EHPVT patients (mean age of 6.1 years) underwent a fSRS procedure. The mean portosystemic gradient change for the cohort was -11.7 mmHg (±4.9). There were no cases of recurrent variceal bleeding or episodes of shunt thrombosis reported after fSRS procedures. CONCLUSIONS: Surgical shunts continue to be an important adjunct in the treatment of complications related to EHPVT. The functional Side-to-Side Splenorenal Shunt is a safe alternative that is easy to perform, involves minimal dissection and requires only a single anastomosis.

Triple gallbladder with heterotopic gastric mucosa: a case report.

BACKGROUND: Triple gallbladder is a rare congenital anomaly of the biliary tract that can be associated with heterotopic tissue. Gallbladder triplication results from the failure of rudimentary bile ducts to regress during embryological development, and can be difficult to distinguish from Todani type II choledochal cysts and biliary duplication cysts. CASE PRESENTATION: A 2-year-old patient presented to our institution with intermittent abdominal pain for 1 year. She had elevated transaminases with imaging concerning for a choledochal cyst. After assessment with magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography, she was diagnosed with a gallbladder multiplication and a common bile duct stricture. She underwent laparoscopic cholecystectomy, which confirmed the diagnosis of triple gallbladder. One of the three gallbladders demonstrated heterotopic gastric mucosa on final pathology, including at the cystic duct margin. Follow up testing with a technetium 99 m scan demonstrated a subtle focus of increased activity in the right upper abdomen at the expected location of the common bile duct, concerning for the presence of residual gastric mucosa. The patient remains well without abdominal pain. CONCLUSIONS: We describe the first case of heterotopic gastric mucosa in a triple gallbladder in a young patient presenting with chronic abdominal pain. We also demonstrate the safety and feasibility of laparoscopic cholecystectomy in young children with triple gallbladder. Finally, we propose an interdisciplinary approach to the management of common bile duct strictures in the setting of ectopic acid secretion, involving a combination of medical management, endoscopic intervention, and possible salvage laparoscopic Roux-en-Y hepaticojejunostomy.

Midaortic syndrome and renovascular hypertension.

Midaortic syndrome (MAS) is a rare condition characterized by stenosis of the abdominal aorta with or without the involvement of branch vessels. The majority of cases are thought to be idiopathic though MAS has been associated with a number of conditions including granulomatous vasculitis, neurofibromatosis-1 (NF-1), Alagille Syndrome, fibromuscular dysplasia (FMD), and Williams syndrome. Patients typically present with hypertension due to decreased renal perfusion. Less common presentations include renal insufficiency, heart failure, claudication, stroke, and abdominal pain. Imaging modalities help establish the diagnosis of MAS including duplex ultrasound, computed tomography angiography (CTA), magnetic resonance angiography (MRA), and angiography. Initial therapy focuses on medical management with antihypertensives prior to intervention. Invasive interventions are indicated when there is evidence of end organ damage or dysfunction such as decreased renal function, poorly growing kidneys, cerebrovascular accident, left ventricular hypertrophy or frank cardiac failure. Endovascular interventions may assist in diagnosis and may treat some lesions although reintervention rates are high. Most patients require some type of surgical intervention, and a variety of surgical options are available based on anatomic findings. Renal revascularization may be accomplished by renal artery bypass, autotransplantation, or renal artery reconstruction. Aortic lesions may be repaired using patch angioplasty or aortoaortic bypass. Mesenteric arteries do not typically require reconstruction as they are rarely symptomatic. More novel options include the use of tissue expanders to lengthen the aorta to allow for primary aortic reconstruction (TESLA) or the use of the meandering mesenteric artery as an autologous aortic bypass graft (MAGIC).

Prenatal diagnosis of rapidly enlarging choledochal cyst with gastric outlet obstruction.

Choledochal cysts are congenital malformations of the biliary tract that involve aberrant configurations of the pancreaticobiliary ductal system. The pathology exists on a spectrum from fusiform dilation of the common bile duct to multiple dilations involving the intra- and extrahepatic bile ducts with potential risks of malignant transformation and hepatic fibrosis. Advancements in ultrasound technology have increased the incidence of prenatal diagnosis of choledochal cysts. Here, we present the case of a prenatally diagnosed initially asymptomatic Type I choledochal cyst with rapid progression in the neonatal period to a complete gastric outlet obstruction within the first month of life. We demonstrate the feasibility of cyst resection and reconstruction with Roux-en-Y hepaticojejunostomy in the neonatal age group. Finally, we discuss management of the case based on evolving imaging findings and laboratory evidence of impending liver dysfunction.

Short Bowel Syndrome and Kidney Transplantation: Challenges, Outcomes, and the Use of Teduglutide.

Among patients with short bowel syndrome who commonly have kidney disease, kidney transplantation remains challenging. We describe the clinicopathologic course of a 59-year old man with short bowel syndrome secondary to Crohn's disease who underwent a deceased donor kidney transplant that was complicated by recurrent acute kidney allograft injury due to volume depletion from diarrhea, ultimately requiring the placement of permanent intravenous access for daily volume expansion at home resulting in the recovery of allograft function. Teduglutide treatment at 1.8 years post-transplant led to a dramatic decrease in diarrhea. A literature review of similar cases yielded 18 patients who underwent 19 kidney transplants. Despite high rates of complications, at the time of last follow-up (median 2.1 years [0.04-7]), 94% of the patients were still alive and 89% had functioning allografts, with a median eGFR of 37.5 [14-122] ml/min/1.73m2. In conclusion, despite high rates of complications, kidney transplantation in patients with short bowel syndrome is associated with acceptable short- and midterm outcomes. Further, we report for the first time the effects of the glucagon-like peptide-2 analogue teduglutide for short bowel syndrome in a kidney transplant recipient.

Resolution of a High Grade and Metastatic BK Polyomavirus-Associated Urothelial Cell Carcinoma Following Radical Allograft Nephroureterectomy and Immune Checkpoint Treatment: A Case Report.

BACKGROUND: BK viral infection in the posttransplant setting continues to cause serious morbidity with effects ranging from allograft nephropathy and dysfunction to urothelial malignancy. RESULTS: In this report, we present a patient that developed BK-associated nephropathy and, 6 years later, locally advanced urothelial malignancy in the renal allograft with nodal, muscle, and extremity involvement. Following radical allograft nephroureterectomy, he was treated with palliative radiation and the immune checkpoint inhibitor atezolizumab. Follow-up imaging at 1 year demonstrated radiographic complete response. CONCLUSIONS: This report supports the growing body of evidence supporting the association of urothelial malignancy and BK virus infection in renal transplant recipients. Further, it highlights the novel application of immune checkpoint inhibitors in the treatment of advanced posttransplant malignancy, in particular when the allograft is removed and the tumor is possibly of donor origin.

Pediatric liver transplant following near catastrophic head bleed: Lessons learned.

Evaluation for liver transplant candidacy is a multidisciplinary effort that involves all aspects of clinical care including social work, nutrition, and a multitude of medical specialties. The prognosis of a pretransplant clinical condition is integrated into the decision to list a patient. Herein, we report a successful liver transplant and recovery of a 3-month-old male following a large right hemispheric subdural hematoma related to acute coagulopathy secondary to undiagnosed end-stage liver disease. On presentation with jaundice, lethargy, and unequal pupils, a CT scan was obtained which demonstrated a large right subdural hematoma with herniation. Once his coagulopathy was corrected, he went for decompressive craniectomy. He survived with medically controlled seizures and improving L-sided neglect and extremity weakness. Six weeks later, given his continued neurologic recovery and worsening liver function, the decision was made to list him for liver transplantation. One month later, he underwent orthotopic liver transplant. His post-operative hospital course was complicated by DVTs and heparin-induced thrombocytopenia, but no neurologic decline, and he was eventually discharged from the hospital on post-op day 26. Three years later, he has a well-functioning allograft and no clinically evident neurologic deficits. The prognosis following pediatric neurologic trauma remains somewhat unclear as recovery and neurologic examinations can be influenced by numerous extrinsic factors. This is one of the first reports of near full neurologic recovery of a pediatric liver transplant recipient following a large subdural hematoma with herniation.

Pediatric liver transplantation.

Considerable strides have been made over the last several decades toward improving outcomes in pediatric liver transplantation. Refinements in surgical technique has allowed for the use of living donor and deceased donor split-liver grafts, thus expanding the pool of available organs and reducing waitlist mortality. The use of a multidisciplinary team continues to be paramount in the care of the transplant recipient. With improvements in overall graft and survival, indications for liver transplantation have also broadened. Currently, pediatric transplant patients have a 5-year survival of over 85%. Long-term morbidity is mainly associated with complications from immunosuppression and chronic rejection. Here we review indications for liver transplantation in children, surgical considerations, post-operative complications, and long-term outcomes.

Clostridium difficile Infections after Blunt Trauma: A Different Patient Population?

BACKGROUND: The epidemiology of Clostridium difficile-associated infection (CDI) has changed, and it is evident that susceptibility is related not only to exposures and bacterial potency, but host factors as well. Several small studies have suggested that CDI after trauma is associated with a different patient phenotype. The purpose of this study was to examine and describe the epidemiologic factors associated with C. difficile in blunt trauma patients without traumatic brain injury using the Trauma-Related Database as a part of the "Inflammation and Host Response to Injury" (Glue Grant) and the University of Florida Integrated Data Repository. METHODS: Previously recorded baseline characteristics, clinical data, and outcomes were compared between groups (67 C. difficile and 384 uncomplicated, 813 intermediate, and 761 complicated non-C. difficile patients) as defined by the Glue Grant on admission and at days seven and 14. RESULTS: The majority of CDI patients experienced complicated or intermediate clinical courses. The mean ages of all cohorts were less than 65 y and CDI patients were significantly older than uncomplicated patients without CDI. The CDI patients had increased days in the hospital and on the ventilator, as well as significantly higher new injury severity scores (NISS), and a greater percentage of patients with NISS >34 points compared with non-CDI patients. They also had greater Marshall and Denver multiple organ dysfunction scores than non-CDI uncomplicated patients, and greater creatinine, alkaline phosphatase, neutrophil count, lactic acid, and PiO2:FiO2 compared with all non-CDI cohorts on admission. In addition, the CDI patients had higher glucose concentrations and base deficit from uncomplicated patients and greater leukocytosis than complicated patients on admission. Several of these changes persisted to days seven and 14. CONCLUSION: Analysis of severe blunt trauma patients with C. difficile, as compared with non-CDI patients, reveals evidence of increased inflammation, immunosuppression, worse acute kidney injury, higher NISS, greater days in the hospital and on the ventilator, higher organ injury scores, and prolonged clinical courses. This supports reports of an increased prevalence of CDI in a younger population not believed previously to be at risk. This unique population may have specific genomic or inflammation-related risk factors that may play more important roles in disease susceptibility. Prospective analysis may allow early identification of at-risk patients, creation of novel therapeutics, and improved understanding of how and why C. difficile colonization transforms into infection after severe blunt trauma.

Successful implementation of a packed red blood cell and fresh frozen plasma transfusion protocol in the surgical intensive care unit.

BACKGROUND: Blood product transfusions are associated with increased morbidity and mortality. The purpose of this study was to determine if implementation of a restrictive protocol for packed red blood cell (PRBC) and fresh frozen plasma (FFP) transfusion safely reduces blood product utilization and costs in a surgical intensive care unit (SICU). STUDY DESIGN: We performed a retrospective, historical control analysis comparing before (PRE) and after (POST) implementation of a restrictive PRBC/FFP transfusion protocol for SICU patients. Univariate analysis was utilized to compare patient demographics and blood product transfusion totals between the PRE and POST cohorts. Multivariate logistic regression models were developed to determine if implementation of the restrictive transfusion protocol is an independent predictor of adverse outcomes after controlling for age, illness severity, and total blood products received. RESULTS: 829 total patients were included in the analysis (PRE, n=372; POST, n=457). Despite higher mean age (56 vs. 52 years, p=0.01) and APACHE II scores (12.5 vs. 11.2, p=0.006), mean units transfused per patient were lower for both packed red blood cells (0.7 vs. 1.2, p=0.03) and fresh frozen plasma (0.3 vs. 1.2, p=0.007) in the POST compared to the PRE cohort, respectively. There was no difference in inpatient mortality between the PRE and POST cohorts (7.5% vs. 9.2%, p=0.39). There was a decreased risk of urinary tract infections (OR 0.47, 95%CI 0.28-0.80) in the POST cohort after controlling for age, illness severity and amount of blood products transfused. CONCLUSIONS: Implementation of a restrictive transfusion protocol can effectively reduce blood product utilization in critically ill surgical patients with no increase in morbidity or mortality.