Personalized medicine: Enhancing our understanding of pediatric growth with analytic morphomics

Evaluation of inguinal sonoanatomy regarding pericapsular nerve group (PENG) block in children: the relation of femoral artery, femoral nerve, lateral femoral cutaneous nerve and iliopsoas notch

BACKGROUND

Pericapsular nerve group (PENG) block is a novel technique that provides analgesia in hip surgeries while preserving motor function. This study aimed to identify developmental differences and variations regarding PENG block sonoanatomy in the inguinal region in children.

METHODS

A total of 150 children between 28 days and 18 years were included in this prospective, observational, descriptive study. The participants were divided into six groups according to growth and development periods. Ultrasonographic measurements representing block depth, needle length, and the vicinity of femoral nerve (FN) and femoral artery (FA) to the block area were collected.

RESULTS

Block depth: 16.2 ± 4.0 mm in infants (28 days-12 months); 33.5 ± 6.1 mm in adolescents (145-215 months). Needle length: 24.2 ± 5.9 mm in infants; 39.3 ± 6.6 mm in adolescents. The distance of FA to the block area: 4.4 ± 2.0 mm in infants; 11.6 ± 5.7 mm in adolescents. The distance of FN to the block area: 0.7 ± 0.8 mm in infants; 2.9 ± 4.0 mm in adolescents. FN-FA distance: 2.2 ± 1.4 mm in infants; 3.8 ± 1.8 mm in adolescents. In 49/150 (32.7%) cases the FN overlapped the perpendicular line between iliopsoas notch and skin. The lateral femoral cutaneous nerve (LFCN) was involved in the ultrasound frame in 11/50 (22%) children under the age of three.

CONCLUSIONS

Especially in children under three years of age, LFCN should be visualized during the pre-block preparation phase. The out-of-plane approach is not recommended in the PENG block due to the FN's alignment on the path of a vertical needle trace.

TRIAL REGISTRATION

NCT04860479.

Skeletal and Adipose Manifestations of Stress in a Contemporary Pediatric Sample

INTRODUCTION

Adverse experiences leading to physiological disruptions (stress) in early life produce cascade effects on various biological systems, including the endocrine and metabolic systems, which, in turn, shape the developing skeletal system. To evaluate the effects of stress on adipose and skeletal tissues, we examine the relationship between skeletal indicators of stress (porotic hyperostosis [PH] and cribra orbitalia [CO]), bone mineral density (BMD), vertebral neural canal (VNC) diameters, and adipose tissue distribution in a contemporary pediatric autopsy sample.

METHODS

Data is from 702 (409 males, 293 females) individuals from a pediatric (0.5-20.9 years) autopsy sample from New Mexico who died between 2011 and 2022. Data includes visceral adipose tissue (VAT) in the abdomen, heart, and liver, CO/PH, VNC size of the fifth lumbar vertebra, and BMD.

RESULTS

We find that adipose tissue distribution and location are differentially associated with CO/PH, BMD, and VNC size; VNC size is smaller, and liver adiposity is higher in those with CO/PH. Further, increased VAT and small VNC size are associated with PH presence and low BMD. Body mass index categories do not correspond with porous cranial lesion presence.

CONCLUSIONS

This paper provides evidence for the complex relationship between skeletal markers of early-life stress (CO/PH, reduced VNC size, low BMD) and endocrine system function. VAT distribution and VNC size are partly shaped by stressors during gestation, likely through alterations of the HPA axis. It is possible that alterations of the HPA axis due to gestational stress also shape the expression of porous cranial lesions during exposure to childhood stressors.

Analyzing Patterns of Skeletal Indicators of Developmental Stress Through the Double Lens of Ontogeny and the Life Course Approach in a Contemporary Reference Sample

OBJECTIVES

Skeletal indicators of developmental stress are commonly used to assess health, disease, and patterns of morbidity and mortality in past populations. Incorporating information about individual life history, such as adverse life events, allows for a more thorough understanding of their etiology. This paper adopts the double lens of ontogeny and the life course to analyze indicators of developmental stress in relation to known individual pathologies and developmental patterns of the cranium, vertebrae, and long bones.

MATERIAL AND METHODS

Six skeletal indicators were collected on CT scans or virtual skeletal reconstructions of 1033 contemporary deceased male and female individuals aged between 0 and 20 years from New Mexico: cribra orbitalia, porotic hyperostosis, Harris lines, stunting, vertebral neural canal diameters, and bone mineral density. Autopsy reports provided information on age, sex, disease type, and duration. Polychoric and polyserial correlations, boxplots, balloon plots, factor analyses of mixed data, and cluster analyses were used to explore patterns among indicators, ontogeny, sex, and disease.

RESULTS

The presence and prevalence of indicators varied depending on age and disease: Harris lines, stunted growth, and cribra orbitalia were common in younger age groups and in cases of long-term or respiratory illnesses, while porotic hyperostosis was more prevalent in adolescent and young adult males.

DISCUSSION

Skeletal indicators of developmental stress are most likely associated with the timing of adverse life events in relation to the corresponding ontogenetic patterns, developmental sensitivity to stressors, and developmental plasticity/canalization of the different skeletal elements that bear them.

The Emerging Role and Clinical Applications of Morphomics in Diagnostic Imaging

Analytic morphomics refers to the accurate measurement of specific biological markers of human body composition in diagnostic medical imaging. The increasing prevalence of disease processes that alter body composition including obesity, cachexia, and sarcopenia has generated interest in specific targeted measurement of these metrics to possibly prevent or reduce negative health outcomes. Typical morphomic measurements include the area and density of muscle, bone, vascular calcification, visceral fat, and subcutaneous fat on a specific validated axial level in the patient's cross-sectional diagnostic imaging. A distinct advantage of these measurements is that they can be made retrospectively and opportunistically with pre-existing datasets. We provide a narrative review of the current state of art in morphomics, but also consider some potential future directions for this exciting field. Imaging based quantitative assessment of body composition has enormous potential across the breadth and scope of modern clinical practice. From risk stratification to treatment planning, and outcome assessment, all can be enhanced with the use of analytic morphomics. Moreover, it is likely that many new opportunities for personalized medicine will emerge as the field evolves. As radiologists, embracing analytic morphomics will enable us to contribute added value in the care of every patient.

Skeletal Muscle Mass Assessment in Pediatric Patients: Development of a Normative Equation and Assessment of Factors Associated With a Low Skeletal Muscle Mass in PICU Patients

OBJECTIVES

To develop an equation for defining a low skeletal muscle mass (SMM) in children and to investigate risk factors and outcomes associated with low SMM in critically ill pediatric patients.

DESIGN

Single-center retrospective pediatric cohorts, 2011-2018.

SETTING

Tertiary Emergency and Critical Care Center of Kyushu University Hospital in Japan.

PATIENTS

We studied two cohorts of pediatric patients 1-15 years old who underwent abdominal CT at the level of the third lumbar vertebra (L3). First a cohort of trauma patients presented to the emergency department in whom we developed an SMM regression equation. Second, a cohort of patients who had undergone abdominal CT within 3 days of PICU admission.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The equation for estimating normal SMM used sex, age, and weight. Low SMM was defined as less than 80% of normal. In the 112 patients in the PICU cohort, median (range) age was 68 (13-191) months, and 83 (74.1%) had underlying disease. There was low SMM in 54 patients (48.2%). Regarding associations, using odds ratio (OR) and 95% CI, we found that low dietary intake (OR 4.33 [95% CI, 1.37-13.70]; p = 0.013) and the presence of underlying disease (OR 7.44 [95% CI, 2.10-26.30]; p = 0.002) were independently associated with greater odds of low SMM. Low SMM, compared with normal SMM, was also associated with longer hospital stays (42.5 d vs. 20.5 d; p = 0.007; β, 1.59; 95% CI, 1.09-2.33; p = 0.016).

CONCLUSIONS

In this retrospective PICU cohort from a single center in Japan, we found that low SMM at PICU admission was present in almost half the cases. Low SMM, as defined by being less than 80% of the normal, was associated with greater odds of low dietary intake and underlying chronic disease. Furthermore, low SMM was associated with longer hospital stays.

Preoperative low muscle mass and early postoperative outcomes in children undergoing living donor liver transplantation: A retrospective study

Low skeletal muscle mass may develop in children with end-stage liver disease, affecting postoperative outcomes. We retrospectively investigated whether preoperative low muscle mass was associated with early postoperative outcomes in pediatric patients undergoing living donor liver transplantation (LDLT). Electronic medical records of children (age below 12 y) who underwent LDLT between February 1, 2007, and January 31, 2018, were reviewed. The cross-sectional areas of psoas, quadratus lumborum, and erector spinae muscles at the level of fourth-fifth lumbar intervertebral disks were measured using abdominal CT images, divided by the square of the height and were added to obtain the total skeletal muscle index (TSMI). The patients were divided into two groups according to the median TSMI in the second quintile (1859.1 mm 2 /m 2 ). Complications in the early postoperative period (within 30 d after surgery) classified as Clavien-Dindo grade 3 or higher were considered major complications. Logistic regression analyses were performed to determine the association between preoperative low muscle mass and early postoperative outcomes. In the study population of 123 patients (median age, 14 mo; range, 8-38 mo) who underwent LDLT, 29% and 71% were classified in the low (mean TSMI, 1642.5 ± 187.0 mm 2 /m 2 ) and high (mean TSMI 2188.1 ± 273.5 mm 2 /m 2 ) muscle mass groups, respectively. The rates of major complications, mechanical ventilation >96 hours, intensive care unit stay >14 days, hospital stay >30 days, and in-hospital mortality were not significantly different between the 2 groups. Additionally, adverse outcomes according to pediatric end-stage liver disease scores and sex were not significantly different between the 2 groups. In conclusion, preoperative low muscle mass defined by TSMI was not associated with early postoperative outcomes in pediatric patients undergoing LDLT.

Pediatric body composition based on automatic segmentation of computed tomography scans: a pilot study

BACKGROUND

Body composition during childhood may predispose to negative health outcomes later in life. Automatic segmentation may assist in quantifying pediatric body composition in children.

OBJECTIVE

To evaluate automatic segmentation for body composition on pediatric computed tomography (CT) scans and to provide normative data on muscle and fat areas throughout childhood using automatic segmentation.

MATERIALS AND METHODS

In this pilot study, 537 children (ages 1-17 years) who underwent abdominal CT after high-energy trauma at a Dutch tertiary center (2002-2019) were retrospectively identified. Of these, the CT images of 493 children (66% boys) were used to establish normative data. Muscle (psoas, paraspinal and abdominal wall) and fat (subcutaneous and visceral) areas were measured at the third lumbar vertebral (L3) level by automatic segmentation. A representative subset of 52 scans was also manually segmented to evaluate the performance of automatic segmentation.

RESULTS

For manually-segmented versus automatically-segmented areas (52 scans), mean Dice coefficients were high for muscle (0.87-0.90) and subcutaneous fat (0.88), but lower for visceral fat (0.60). In the control group, muscle area was comparable for both sexes until the age of 13 years, whereafter, boys developed relatively more muscle. From a young age, boys were more prone to visceral fat storage than girls. Overall, boys had significantly higher visceral-to-subcutaneous fat ratios (median 1.1 vs. 0.6, P<0.01) and girls higher fat-to-muscle ratios (median 1.0 vs. 0.7, P<0.01).

CONCLUSION

Automatic segmentation of L3-level muscle and fat areas allows for accurate quantification of pediatric body composition. Using automatic segmentation, the development in muscle and fat distribution during childhood (in otherwise healthy) Dutch children was demonstrated.

Establishment and validation of reference values for abdominal skeletal muscle compartments in children

BACKGROUND & AIMS

Sarcopenia, resulting from skeletal muscle loss, is a serious concern in children, for whom nutrition and physical activity are essential for growth. In sarcopenia research, the skeletal muscle mass is often obtained from computed tomography (CT) cross-sectional images in both adults and children; however, the method of evaluating skeletal muscle using CT, especially the area range to be measured, has not yet been validated in children. The aim of this study is to establish reference values for three compartments of the abdominal skeletal muscle area (aSMA) obtained from cross-sectional CT images, and to validate the differences among them by assessing correlations with physical development.

METHODS

We conducted a single-centre, retrospective, cross-sectional study and included patients aged 1-17 years who underwent abdominal CT at Chiba University Hospital from 2007 to 2020. Patients with chronic diseases such as malignant tumours and inflammatory bowel disease were excluded from the analysis. aSMA was obtained from CT cross-sections at the lumbar L3-L4 intervertebral disc level by dividing it into three compartments: the psoas muscle area (PMA), paraspinal muscle area (PSMA), and total skeletal muscle area (TSMA). Quartile regression curves by sex and muscle compartment were generated using non-crossover and nonparametric regression quantile estimation. The correlation between each compartment of aSMA with height and weight was assessed using Spearman's rank correlation coefficient.

RESULTS

We analysed the abdominal CT images of 593 children (male: n = 335, female: n = 258) and generated curves predictive for the 5th, 25th, 50th, 75th, and 95th percentiles for each compartment of aSMA by sex. In patients aged 13 years and older, boys had significantly larger aSMA areas than girls in all three compartments. Among the three compartments, PSMA had the strongest correlation coefficient with height and weight for both boys and girls.

CONCLUSIONS

We generated quantile regression curves for three aSMA compartments obtained from cross-sectional CT images and established reference values in children. PSMA values were most strongly correlated with height and weight among the three aSMA compartments.

Low bone mineral density is associated with fatty liver disease and respiratory illness in a pediatric mortality sample

This study finds that fatty liver disease is associated with low bone density in a pediatric mortality sample. Since non-alcoholic fatty liver disease has increased in prevalence over the past few decades among children, a better understanding of the disease's impacts on bone health is of significance to clinicians.

PURPOSE

Chronic illness leads to decreased bone modeling and remodeling. This can be especially problematic during childhood and adolescence, since the majority of an individual's peak bone mass is achieved by the age of 20. In this study, we examine relationships between chronic illness and low bone mineral density (BMD) in a pediatric mortality sample (aged 0.5 to 20.9 years) from New Mexico. We also test whether low BMD is related to decelerated linear growth by examining its relationship to growth stunting and arrest (Harris lines).

METHODS

Hounsfield units (HU), a proxy for trabecular BMD, were obtained at the fourth lumbar vertebra and the femoral neck from postmortem CT scans. Linear regression was used to examine associations between z-standardized HU and age, sex, medical conditions, Harris lines, and growth stunting.

RESULTS

We find that lumbar HU is significantly lower for individuals with fatty liver disease and respiratory illness; femoral HU is significantly lower in individuals with Harris lines.

CONCLUSION

The mechanisms of low BMD in individuals with fatty liver disease and respiratory illness are likely multifactorial and involve vitamin D deficiency (malnutrition, malabsorption), systemic inflammation, and sedentary lifestyles. However, better awareness of this relationship can provide clinicians with the ability to introduce nutritional and behavioral interventions early to mitigate deleterious effects on bone. Harris lines, on the other hand, mark temporary growth cessation due to physiological stress followed by a rapid resumption of growth. Low BMD in these individuals may be due to bone mineralization lagging behind relatively rapid linear growth.

Reference values for MRI-derived psoas and paraspinal muscles and macroscopic fat infiltrations in paraspinal muscles in children

BACKGROUND

Sarcopenia, defined as loss of skeletal muscle mass, is a novel term associated with adverse outcomes in children. Magnetic Resonance Imaging (MRI) is a safe and precise technique for measuring tissue compartments and is commonly used in most routine paediatric imaging protocols. Currently, there is a lack of MRI-derived normative data which can help in determining the level of sarcopenia. This study aimed to introduce reference values of total psoas muscle area (tPMA), total paraspinal muscle area (tPSMA), and total macroscopic fat infiltrations of the PSMA (tMFI).

METHODS

In this retrospective study, the local database was searched for abdominal and pelvic region MRI studies of children aged from 1 to 18 years (mean age (standard deviation (SD)) of 9.8 (5.5) years) performed in the years 2010-2021. Children with chronic diseases and a history of surgical interventions were excluded from the analysis. Finally, a total of 465 healthy children (n = 233 girls, n = 232 boys) were enrolled in the study. The values of the tPMA, tPMSA, and tMFI were measured in square centimetres (cm² ) at the level of the L4/L5 intervertebral disc as the sum of the left and right regions. Age-specific and sex-specific muscle, fat, and body mass index percentile charts were constructed using the LMS method. Inter-observer agreement and intra-observer reproducibility were assessed using the Bland-Altman plots.

RESULTS

Both tPMA and tPSMA showed continuous increases in size (in cm² ) throughout all age groups. At the age of 18, the median tPMA areas reached 26.37 cm² in girls and 40.43 cm² in boys. Corresponding tPSMA values were higher, reaching the level of 40.76 cm² in girls and 56.66 cm² in boys. The mean value of tMFI within the paraspinal muscles was 5.0% (SD 3.65%) of their total area in girls and 3.5% (SD 2.25%) in boys with the actual difference between sexes up to 0.96 cm² . Excellent intra-observer reproducibility and inter-observer agreement were noted. Actual mean differences for tPMA were at the level of 0.43 and 0.39 cm² , respectively. Mean bias for tPSMA was 0.1 cm² for inter-observer and 0.05 cm² for intra-observer measurements.

CONCLUSIONS

Our findings demonstrate novel and highly reproducible sex-specific MRI-derived reference values of tPMS, tPSMA, and tMFI at the level of the L4/L5 intervertebral disc for children from 1 to 18 years old, which may guide a clinician in the assessment of sarcopenia, a prognostic outcome marker in children.

Defining Normal Ranges of Skeletal Muscle Area and Skeletal Muscle Index in Children on CT Using an Automated Deep Learning Pipeline: Implications for Sarcopenia Diagnosis

BACKGROUND. Skeletal muscle area (SMA), representing skeletal muscle cross-sectional area at the L3 vertebral level, and skeletal muscle index (SMI), representing height-normalized SMA, can serve as markers of sarcopenia. Normal SMA and SMI values have been reported primarily in adults. OBJECTIVE. The purpose of this study was to use an automated deep learning (DL) pipeline for muscle segmentation on abdominal CT to define normative age- and sex-based values for pediatric muscle cross-sectional area as a guide for diagnosis of sarcopenia in children. METHODS. This retrospective study reviewed records of patients who underwent abdominal CT at Cincinnati Children's Hospital Medical Center from January 1, 2009, to January 3, 2019. Patients were excluded on the basis of age outside of the eligible range (2.00-18.99 years), body mass index (BMI) outside of 5-95% age-based percentiles using CDC and WHO growth charts, known medical condition, medication use, support devices, surgery, or missing axial images at the L3 level. A previously validated automated DL pipeline was used to identify an axial slice at L3 and segment skeletal muscle to generate SMA and SMI. Pearson correlation coefficients were computed. Quantile regression analysis was used to plot SMA and SMI as functions of age and sex and to determine age- and sex-based percentile values. RESULTS. Of 8817 patients who underwent abdominal CT during the study period, 2168 (mean age, 12.3 ± 4.3 [SD] years; 1125 female patients, 1043 male patients) met inclusion criteria. Mean BMI-for-age percentile based on CDC and WHO growth charts was 64.8% ± 25.3% for female patients and 61.4% ± 25.8% for male patients. SMA showed strong correlation with weight, height, age, and BMI for male (0.79-0.94) and female (0.75-0.90) patients; SMI showed weak-to-moderate correlation with weight, height, age, and BMI for male (0.25-0.57) and female (0-0.43) patients. Normal SMA and SMI ranges for age and sex were expressed as curves and as a lookup table, identifying 54 male and 59 female patients with muscle measurements below the 5th percentile regression curve. CONCLUSION. By using an automated DL pipeline in a large sample of carefully selected children, normal ranges for SMA and SMI were calculated as functions of age and sex. CLINICAL IMPACT. The normative values should aid the diagnosis of sarcopenia in children.

Sarcopenia prevalence in pediatric intestinal transplant recipients: Implications on post-transplant outcomes

BACKGROUND

Sarcopenia has been associated with poor surgical outcomes but has not been studied in pediatric intestinal transplantation. We aimed to determine sarcopenia prevalence in intestinal transplant recipients and the association of sarcopenia with outcomes.

METHODS

We performed a cross-sectional retrospective chart review of intestinal transplant recipients from 2000-present. We estimated total psoas muscle area (tPMA) at L3-L4 and L4-L5 from computed tomography scans prior to or in the immediate peri-operative period. Sarcopenia was defined by tPMA below the 5^th percentile for age and sex. We built a Cox-proportional hazards model to determine the association between sarcopenia and patient and graft survival.

RESULTS

Of the 56 intestinal transplant recipients included, 36 (64%) were sarcopenic. Graft survival was 79% at one year and 59% at five years. Overall patient survival was 86% at one year and 76% at five years. Peri-transplant sarcopenia was associated with improved graft survival (Hazard ratio 0.42, 95% confidence interval: 0.20-0.88) but not overall survival (Hazard ratio 0.47, 95% confidence interval: 0.19-1.20).

CONCLUSIONS

In this first report of sarcopenia in pediatric intestinal transplant, we found a high sarcopenia prevalence without an association with worse outcomes. The potential improved graft survival in sarcopenic patients along with underlying mechanisms warrant further exploration.

Sarcopenia in Children with Solid Organ Tumors: An Instrumental Era

Sarcopenia has recently been studied in both adults and children and was found to be a prognostic marker for adverse outcome in a variety of patient groups. Our research showed that sarcopenia is a relevant marker in predicting outcome in children with solid organ tumors, such as hepatoblastoma and neuroblastoma. This was especially true in very ill, high-risk groups. Children with cancer have a higher likelihood of ongoing loss of skeletal muscle mass due to a mismatch in energy intake and expenditure. Additionally, the effects of cancer therapy, hormonal alterations, chronic inflammation, multi-organ dysfunction, and a hypermetabolic state all contribute to a loss of skeletal muscle mass. Sarcopenia seems to be able to pinpoint this waste to a high degree in a new and objective way, making it an additional tool in predicting and improving outcome in children. This article focuses on the current state of sarcopenia in children with solid organ tumors. It details the pathophysiological mechanisms behind sarcopenia, highlighting the technical features of the available methods for measuring muscle mass, strength, and function, including artificial intelligence (AI)-based techniques. It also reviews the latest research on sarcopenia in children, focusing on children with solid organ tumors.

Sarcopenia is highly prevalent in children with autoimmune liver diseases and is linked to visceral fat and parent-perceived general health

BACKGROUND

Patients with autoimmune hepatitis (AIH) and primary or autoimmune sclerosing cholangitis are at nutritional risk; their body composition and has not been extensively studied. We aimed to describe their body composition and identify clinical links.

METHODS

Using magnetic resonance imaging (MRI), two reviewers segmented total psoas muscle area (tPMSA), visceral fat area (VFA) and subcutaneous fat area (mm2 ) and measured visceral and subcutaneous thickness (mm). Clinical, laboratory and quality of life (QoL; using PedsQL) data were collected. Sarcopenia was defined as tPMSA ≤5th percentile. Analysis of variance, Wilcoxon rank test and multivariable modelling were performed. A paediatric cohort with non-alcoholic fatty liver disease (NAFLD) was used as a comparator following propensity score matching.

RESULTS

Fifty-eight patients with autoimmune liver disease (AILD) (33 [57%] with AIH) were included: median age 16 years (interquartile range [IQR]: 13-18), 33 (57%) male. Median time from diagnosis to MRI was 15 months (IQR: 2-39 months). Two patients (3%) had a BMIz indicative of mild malnutrition. tPMSA was measurable in 52 subjects (90%). Of those, 25 (48%) had sarcopenia. Sarcopenic patients had a lower blood urea nitrogen compared to non-sarcopenic (median [IQR]: 9.5 [8.0, 12.0] vs 11 [10, 14] mg/dL; P = .023). There was no difference in corticosteroid use between groups. The VFA of sarcopenic patients was higher (3156 [2064, 7492]) vs 2084 [688, 3092]) mm2 ; P = .005). Patient-reported QoL negatively associated with VFA and general health negatively associated with VFA. Compared with NAFLD, the odds ratio for sarcopenia with AILD was 14.5 (95% confidence interval: 2.3-90.7).

CONCLUSION

In autoimmune liver diseases, sarcopenia is highly prevalent, associated with increased visceral fat and QoL.

Does sarcopenia affect outcomes in pediatric surgical patients? A scoping review

OBJECTIVE

Adults with sarcopenia have a greater risk of postoperative complications, a higher rate of ICU admission, and an increased length of hospital stay. Few studies have explored the prevalence or importance of sarcopenia in the pediatric population. This study reviews the published literature on sarcopenia in the pediatric population, including pediatric surgery.

METHODS

Original studies related to sarcopenia in children were identified using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines and the PubMed database.

RESULTS

A total of 390 articles were screened, with 28 meeting inclusion criteria. Twenty (71%) studies provided a means to define abnormal and 18 studies (64%) showed that a specific disease process could impact lean muscle mass in children. Only 4 (14%) studies associated the change in muscle mass with an outcome. Two studies investigated sarcopenia and outcomes in the pediatric surgical patient and demonstrated associations with worse outcomes.

CONCLUSION

Despite studies showing an association between sarcopenia and negative outcomes in the adult surgical population, there remains a paucity of evidence regarding the impact of sarcopenia on the pediatric population. Future studies are needed to ascertain the relationship between muscle mass and outcomes in pediatric surgical patients.

Total Psoas Muscle Area as a Marker for Sarcopenia Is Related to Outcome in Children With Neuroblastoma

Background: Sarcopenia describes a generalized loss of skeletal muscle mass, strength, or function. Determined by measuring the total psoas muscle area (tPMA) on cross-sectional imaging, sarcopenia is an independent marker for poor post-surgical outcomes in adults and children. Children with cancer are at high risk for sarcopenia due to immobility, chemotherapy, and cachexia. We hypothesize that sarcopenic children with neuroblastoma are at higher risk for poor post-operative outcomes. Patients and Methods: Retrospective analysis of children with neuroblastoma ages 1-15 years who were treated at our hospital from 2008 to 2016 with follow-up through March 2021. Psoas muscle area (PMA) was measured from cross-sectional images, using computed tomography (CT) and magnetic resonance imaging (MRI) scans at lumbar disc levels L3-4 and L4-5. tPMA is the sum of the left and right PMA. Z-scores were calculated using age- and gender-specific reference values. Sarcopenia was defined as a tPMA z-score below -2. A correlation of tPMA z-scores and sarcopenia with clinical variables and outcome was performed. Results: One hundred and sixty-four children with workup for neuroblastoma were identified, and 101 children fulfilled inclusion criteria for further analysis, with a mean age of 3.92 years (SD 2.71 years). Mean tPMA z-score at L4-5 was -2.37 (SD 1.02). Correlation of tPMA z-score at L4-5 with weight-for-age z-score was moderate (r = 0.54; 95% CI, 0.38, 0.66). No association between sarcopenia and short-term outcome was observed. Sarcopenia had a sensitivity of 0.82 (95% CI, 0.62-0.93) and a specificity of 0.48 (95% CI 0.36-0.61) in predicting 5-year survival. In a multiple regression analysis, pre-operative sarcopenia, pre-operative chemotherapy in the NB2004 high-risk group, unfavorable tumor histology, and age at diagnosis were associated with 5-year survival after surgery, with hazard ratios of 4.18 (95% CI 1.01-17.26), 2.46 (95% CI 1.02-5.92), 2.39 (95% CI 1.03-5.54), and 1.01 (95% CI 1.00-1.03), respectively. Conclusion: In this study, the majority of children had low tPMA z-scores and sarcopenia was a risk factor for decreased 5-year survival in children with neuroblastoma. Therefore, we suggest measuring the tPMA from pre-surgical cross-sectional imaging as a biomarker for additional risk stratification in children with neuroblastoma.

Low psoas muscle index as an unfavorable factor in children with end-stage liver disease undergoing liver transplantation

Sarcopenia is common in cirrhotic adults and associated with waitlist mortality and worse outcome after liver transplantation. Psoas muscle mass has been used to define sarcopenia. Therefore, we aimed to determine the association between psoas muscle mass and waitlist mortality as well as post-transplant outcome in children with end-stage liver disease. Medical records and abdominal imaging of pediatric liver transplant candidates during 2010-2019 were reviewed. A subset of images was measured by two radiologists to determine inter-rater reliability. Psoas muscle surface area was determined at intervertebral lumbar disk 3-4 (L3-4) and 4-5 (L4-5) levels. PMI was calculated by psoas muscle surface area divided by height squared. We included 105 children, most with biliary atresia (84%). Patients with waitlist mortality had lower PMI compared to the ones who survived to transplantation (PMI at L3-4 levels 352.8 ± 162.5 vs. 416.8 ± 136.2 mm² /m² and at L4-5 levels 497.3 ± 167.8 vs. 571.4 ± 163.4 mm² /m² , both p = .04), but not in the multivariate analyses. For transplanted patients (n = 75), a higher rate of re-operation (39% vs. 15%, p = .03) and longer hospital stay (53 vs. 45 days, p = .02) were found in patients with lower PMI. Lower PMI is associated with higher re-operation rate and longer hospital stay following transplantation, but not waitlist mortality. PMI may be taken into consideration with other biomarkers to predict post-transplant complications.

Higher Mortality in Pediatric Liver Transplant Candidates With Sarcopenia

Little is known about the impact of sarcopenia (reduced muscle mass and function) in pediatric chronic liver disease. We compared psoas muscle surface area (PMSA), measured at the 4th lumbar vertebrae, in children listed for liver transplantation (LT) to that of healthy controls and studied the impact of sarcopenia on transplant-associated outcomes. The effect of PMSA (raw value and z score) on survival was studied using multivariable proportional hazards, whereas the impact of PMSA on other transplant-associated outcomes was assessed by multivariable linear or logistic regression. The correlation of PMSA with anthropometric values and markers of disease severity was studied using Spearman's rank-order correlation. Mean PMSA was significantly lower in LT candidates (n = 57, 699.4 ± 591.9 mm² [mean ± SD]) than controls (n = 53, 1052.9 ± 960.7 mm² ; P = 0.02). For LT candidates, there was an increased risk of death (either while on the waiting list or following transplantation) with lower PMSA (hazard ratio [HR], 1.6 per 100 mm² [P = 0.03]; 95% confidence interval [CI], 1.1-2.8), amounting to a 4.9 times higher risk of death for every 1 unit decrease in PMSA z score (HR, 4.9 [P = 0.05], 95% CI, 1.2-34.5), adjusting for age and sex. PMSA did not correlate with posttransplant length of intubation, hospital length of stay, or perioperative complications. PMSA also did not correlate with calculated (r = 0.10, P = 0.60) or appealed Model for End-Stage Liver Disease/Pediatric End-Stage Liver Disease scores (r = 0.10, P = 0.69). Pediatric LT candidates have a significant reduction in muscle compared with controls. LT candidates with lower PMSA experience significant increases in mortality. As such, sarcopenia may provide a novel indicator of disease severity in children with chronic liver disease.

Sarcopenia is a Predictor for Adverse Clinical Outcome in Pediatric Inflammatory Bowel Disease

OBJECTIVES

Inflammatory bowel disease (IBD) has a high impact on nutritional status. Sarcopenia is related to higher risk of surgery and rescue therapy in adults with IBD; however, comparable data in pediatric populations are scarce. We evaluated muscle mass as a predictor of disease outcome in pediatric IBD.

METHODS

All pediatric IBD patients who underwent magnetic resonance enterography (MRE) during 2008 to 2019 were included. Muscle mass was assessed by measuring the area of the psoas muscle at the upper level of L3 on MRE. The psoas area divided by the body surface area (BSA) yielded the psoas index. Clinical and radiological data, including disease location, activity, course, and medications were documented. The control group included non-IBD children who underwent an MR imaging study.

RESULTS

We enrolled 101 IBD patients, 69 (68.3%) with Crohn disease (CD) and 32 (31.7%) with ulcerative colitis (UC) (mean age 15.03 ± 3.27 years). The psoas index was significantly lower in the IBD patients compared with the 87 controls (326 vs 528, respectively, P < 0.001). Patients with a psoas index in the lowest quartile had significantly higher risk for biologic therapy (multivariate analysis, hazard ratio [HR] = 12.1, P = 0.046) and disease exacerbation (HR = 9, P = 0.047) independently of body mass index, compared with patients with a psoas index in the uppermost quartile.

CONCLUSIONS

Sarcopenia correlates with the radiological severity of pediatric IBD and serves as a predictor for adverse clinical disease outcome. Muscle mass measurement in MRE studies may serve as a possible marker for disease outcome in this population.

Sarcopenia in Children With End-Stage Liver Disease on the Transplant Waiting List

Sarcopenia predicts morbidity and mortality in adults with end-stage liver disease (ESLD) and is determined by total psoas muscle area (tPMA) measurement from computed tomography (CT) imaging. Recently developed pediatric age- and sex-specific tPMA growth curves provide the opportunity to ascertain prevalence and impact of sarcopenia in children awaiting liver transplantation (LT). This retrospective single-center study evaluated sarcopenia in children between 1 and 16 years with ESLD and a clinically indicated abdominal CT less than 3 months before first isolated LT. Sarcopenia was defined as tPMA z score less than -2 measured at the intervertebral L4-5 level. Patient demographic, biochemical, and outcome data were recorded. tPMA was compared with other measures of nutritional status using univariate and multivariate logistic analyses. Outcome measures included 1-year morbidity events and mortality after LT. CT images from 25 (64% female) children with median age of 5.50 (interquartile range [IQR], 3.75-11.33) years were reviewed. Ten children (40%) had a tPMA z score less than -2. Sarcopenia was associated with lower z scores for weight (odds ratio [OR], 0.38; P = 0.02), height (OR, 0.32; P = 0.03), and nutritional support before LT (OR, 12.93; P = 0.01). Sarcopenic children had a longer duration of pediatric intensive care unit (PICU) stay (3.50 [IQR, 3.00-6.00] versus 2.00 [IQR, 2.00-3.50] days; P = 0.03). Sarcopenia was prevalent in 40% of children with ESLD awaiting LT, and lower tPMA z score was associated with deficient anthropometrics and need for nutritional support before LT. Post-LT PICU duration was increased in children with sarcopenia, reflecting adverse outcomes associated with muscle loss. Further studies are needed to elucidate the underlying mechanisms of sarcopenia in children with ESLD.

Morphometric Changes in Children With Small Bowel Crohn Disease During Induction of Therapy: A Pilot Study

OBJECTIVE

Children and adolescents with Crohn disease (CD) commonly gain weight during treatment induction, which is thought to be a marker of better health. Body composition is, however, rarely assessed at diagnosis, and changes during early treatment are not often quantified. Therefore, it is unknown if these gains are truly healthy. We sought to evaluate skeletal muscle changes during initial treatment for CD by using routine imaging.

METHODS

Single-center prospective study. Pediatric patients diagnosed with small bowel CD underwent serial magnetic resonance enterography (MRE) imaging, laboratory testing, and disease-activity assessment, at diagnosis, 1 and 6 months of treatment. MRE-based cross-sectional morphometry was used to measure psoas muscle cross sectional area (CSA). Psoas CSA z-scores were calculated using normative data.

RESULTS

We enrolled 30 children (ages 9--17 years). Twenty-eight of 30 (93%) received anti-tumor necrosis factor therapy and 4 required surgical resection. Children with below-average psoas CSA and body mass index (BMI) z-scores at diagnosis were much more likely to fail treatment or undergo surgery by 6 months compared with those with higher z-scores (55% vs 0%; P = 0.001). Children with no activity limitations at diagnosis had significantly larger muscle gains in the first month, compared with those whose activity was limited at diagnosis (P = 0.012). Most patients had higher psoas CSA z-scores by 6 months, and these increases were associated with weight and BMI z-score increases.

CONCLUSIONS

Skeletal muscle growth contributes to weight gain during treatment induction in most patients with CD. Psoas muscle CSA on diagnostic imaging may have prognostic value in children with CD.

Establishing Reference Values for Lean Muscle Mass in the Pediatric Patient

OBJECTIVES

Adults with decreased muscle mass experience worse outcomes and more frequent complications. The effects of sarcopenia on pediatric outcomes are unknown. Our objective was to define reference values for lean muscle mass in a healthy pediatric population to facilitate future studies on the impact of lean muscle mass on pediatric outcomes.

PATIENTS AND METHODS

Bilateral psoas muscle surface area was measured by computed tomography in a healthy pediatric population undergoing evaluation after trauma. Pearson correlation coefficients (PCCs) were calculated for age, weight, height, body mass index (BMI), total psoas muscle area, and psoas muscle index (PMI; defined as psoas muscle area divided by height squared). Quantile regression was used to determine age- and sex-specific percentiles of psoas muscle area and PMI.

RESULTS

Analysis of 494 male and 288 female patients with available imaging (median age: 9.3 years, interquartile range: 5.4-13.4; 63.1% male) was performed. For males, age correlated strongly with total psoas volume (PCC = 0.87), height (0.95), and weight (0.88) and poorly with BMI (0.45). In females, age correlated strongly with total psoas volume (0.88), height (0.92), weight (0.88) and poorly with BMI (0.19). Gender-specific curves and charts were created using output from the quantile regression from reference values of the total psoas muscle area corresponding to the 25th, 50th, and 75th percentiles across all ages.

CONCLUSIONS

We created gender-specific reference charts for total and height-normalized psoas muscle area in healthy children based on age. These results can be used in future studies to establish the effects of sarcopenia in pediatric patients.

CT validation of SVC-RA junction location for pediatric central line placement: is vertebral bodies below the carina accurate?

PURPOSE

The key landmark for tip position of a central venous catheter (CVC) is the SVC-RA junction. In adults, localization of the SVC-RA junction may be assessed as a function of vertebral body units (VBU) below the carina during CVC placement. We investigated the relationship between the SVC-RA junction and the carina in children.

MATERIALS AND METHODS

584 CT scans of 0-18 years were analyzed. The carina was marked automatically by software while the SVC-RA junction and vertebrae were marked manually. The SVC-RA junction to carina (JC) distance was the primary study measurement reported in both VBU and mm.

RESULTS

The data show an average JC distance of 1.25 VBU for 0-1 year, 1.27 VBU for 1-4 years, 1.34 VBU for 4-9 years, 1.53 VBU for 9-15 years, and 1.64 VBU for 15-18 years. A positive relationship between weight and JC distance was also demonstrated.

CONCLUSION

JC distance is a useful predictor of SVC-RA junction location in children. Significant relationships were shown between JC distance and both age and weight. Due to small differences between age groups, however, average JC distance for all comers (1.48 VBU, 95% CI 0.7 - 2.3) can be used for SVC-RA junction identification in CVC placement.

Morphomic Signatures Derived from Computed Tomography Predict Hepatocellular Carcinoma Occurrence in Cirrhotic Patients

BACKGROUND AND AIMS

Computed tomography (CT) provides scans of the human body from which digitized features can be extracted. The aim of this study was to examine the role of these digital biomarkers for predicting subsequent occurrence of hepatocellular carcinoma (HCC) in cirrhotic patients.

METHODS

A cohort of 269 patients with cirrhosis were recruited and prospectively followed for the occurrence of HCC in Taiwan. CT scans were retrospectively retrieved and computationally processed using analytic morphomics. A predictive score was constructed using Cox regression and the generalized iterative modeling method, maximizing the log likelihood of the time to HCC development. An independent cohort of 274 patients from University of Michigan was utilized to examine the predictive validity of this score in a Western population.

RESULTS

Of the 27 digitized features at the 12th thoracic vertebral level, six features were significantly associated with HCC occurrence. Two digitized features (fascia eccentricity and the bone mineral density) were able to stratify patients into high- and low-risk groups with distinct cumulative incidence of HCC in both the training and validation cohorts (P = 0.015 and 0.044, respectively). When the two digitized features were tested in the Michigan cohort, only bone mineral density remained an effective predictor.

CONCLUSION

Digitized features derived from the CT were effective in predicting subsequent occurrence of HCC in cirrhosis patients. The bone mineral density measured on CT was an effective predictor for patients in both Taiwan and USA.

Paediatric reference values for total psoas muscle area

BACKGROUND

Sarcopenia, the unintentional loss of skeletal muscle mass, is associated with poor outcomes in adult patient populations. In adults, sarcopenia is often ascertained by cross-sectional imaging of the psoas muscle area (PMA). Although children with chronic medical illnesses may be at increased risk for muscle loss because of nutritional deficiencies, physical deconditioning, endocrine anomalies, and systemic inflammation, consistent quantitative definitions for sarcopenia in children are lacking. We aimed to generate paediatric reference values for PMA at two intervertebral lumbar levels, L3-4 and L4-5.

METHODS

In this cross-sectional study, we analysed abdominal computed tomography scans of consecutive children presenting to the emergency department. Participants were children 1-16 years who required abdominal cross-sectional imaging after paediatric trauma between January 1, 2005 and December 31, 2015 in a large Canadian quaternary care centre. Children with a documented chronic medical illness or an acute spinal trauma at presentation were excluded. Total PMA (tPMA) at levels L3-4 and L4-5 were measured in square millimetres (mm² ) as the sum of left and right PMA. Age-specific and sex-specific tPMA percentile curves were modelled using quantile regression.

RESULTS

Computed tomography images from 779 children were included. Values of tPMA at L4-5 were significantly larger than at L3-4 at all ages, but their correlation was high for both girls (r = 0.95) and boys (r = 0.98). Amongst girls, tPMA 50th percentile values ranged from 365 to 2336 mm² at L3-4 and from 447 to 2704 mm² for L4-5. Amongst boys, 50th percentile values for tPMA ranged between 394 and 3050 mm² at L3-4 and from 498 to 3513 mm² at L4-5. Intraclass correlation coefficients were excellent at L3-4 (0.97, 95% CI 0.94 to 0.981) and L4-5 (0.99, 95% CI 0.986 to 0.995). Weight and tPMA were correlated, stratified by sex for boys (L3-4 r = 0.90; L4-5 r = 0.90) and for girls (L3-4 r = 0.87; L4-5 r = 0.87). An online application was subsequently developed to easily calculate age-specific and sex-specific z-scores and percentiles.

CONCLUSIONS

We provide novel paediatric age-specific and sex-specific growth curves for tPMA at intervertebral L3-4 and L4-5 levels for children between the ages of 1-16 years. Together with an online tool (https://ahrc-apps.shinyapps.io/sarcopenia/), these tPMA curves should serve as a reference enabling earlier identification and targeted intervention of sarcopenia in children with chronic medical conditions.

A North American Expert Opinion Statement on Sarcopenia in Liver Transplantation

Loss of muscle mass and function, or sarcopenia, is a common feature of cirrhosis and contributes significantly to morbidity and mortality in this population. Sarcopenia is a main indicator of adverse outcomes in this population, including poor quality of life, hepatic decompensation, mortality in patients with cirrhosis evaluated for liver transplantation (LT), longer hospital and intensive care unit stay, higher incidence of infection following LT, and higher overall health care cost. Although it is clear that muscle mass is an important predictor of LT outcomes, many questions remain, including the best modality for assessing muscle mass, the optimal cut-off values for sarcopenia, the ideal timing and frequency of muscle mass assessment, and how to best incorporate the concept of sarcopenia into clinical decision making. For these reasons, we assembled a group of experts to form the North American Working Group on Sarcopenia in Liver Transplantation to use evidence from the medical literature to address these outstanding questions regarding sarcopenia in LT. We believe sarcopenia assessment should be considered in all patients with cirrhosis evaluated for liver transplantation. Skeletal muscle index (SMI) assessed by computed tomography constitutes the best-studied technique for assessing sarcopenia in patients with cirrhosis. Cut-off values for sarcopenia, defined as SMI < 50 cm2 /m2 in male and < 39 cm2 /m2 in female patients, constitute the validated definition for sarcopenia in patients with cirrhosis. Conclusion: The management of sarcopenia requires a multipronged approach including nutrition, exercise, and additional pharmacological therapy as deemed necessary. Future studies should evaluate whether recovery of sarcopenia with nutritional management in combination with an exercise program is sustainable as well as how improvement in muscle mass might be associated with improvement in clinical outcomes.

Sarcopenia in Chronic Liver Disease: Impact on Outcomes

Malnutrition is a common complication in patients with end-stage liver disease (ESLD) awaiting liver transplantation (LT). Malnutrition and sarcopenia overlap in etiology and outcomes, with sarcopenia being defined as reduced skeletal muscle mass and muscle function. The purpose of this review was to identify the prevalence of sarcopenia with and without obesity in adults and children with ESLD and to assess the methodological considerations in sarcopenia diagnosis and the association of sarcopenia with pre- and post-LT outcomes. A total of 38 articles (35 adult and 3 pediatric articles) retrieved from PubMed or Web of Science databases were included. In adults, the prevalence rates of pre-LT sarcopenia, pre-LT sarcopenic obesity (SO), post-LT sarcopenia, and post-LT SO were 14%-78%, 2%-42%, 30%-100%, and 88%, respectively. Only 2 adult studies assessed muscle function in patients diagnosed with sarcopenia. The presence of pre-LT sarcopenia is associated with higher wait-list mortality, greater postoperative mortality, higher infection risk and postoperative complications, longer intensive care unit (ICU) stay, and ventilator dependency. The emerging pediatric data suggest that sarcopenia is prevalent in pre- and post-LT periods. In 1 pediatric study, sarcopenia was associated with poor growth, longer perioperative length of stay (total/ICU) and ventilator dependency, and increased rehospitalization in children after LT. In conclusion, there is a high prevalence of sarcopenia in adults and children with ESLD. Sarcopenia is associated with adverse clinical outcomes. The present review is limited by heterogeneity in the definition of sarcopenia and in the methodological approaches in assessing sarcopenia. Future studies are needed to standardize the sarcopenia diagnosis and muscle function assessment, particularly in the pediatric population, to enable early identification and treatment of sarcopenia in adults and children with ESLD.

Pediatric Sarcopenia: A Paradigm in the Overall Definition of Malnutrition in Children?

BACKGROUND

Malnutrition is a common complication in children with chronic diseases. Sarcopenia is one component of malnutrition, characterized by reduced skeletal muscle mass (SMM) and muscle function. The presence of sarcopenia is associated with adverse outcomes in children. Although there is growing research interest in sarcopenia, no review has been done on this novel concept in pediatrics. The purpose of this review was to explore current evidence in sarcopenia with and without obesity and to evaluate the knowledge gaps in the assessment of childhood sarcopenia.

METHODS

A total of 12 articles retrieved from PubMed or Web of Science databases were included.

RESULTS

Limited studies have elucidated sarcopenia in pediatrics. Challenges in sarcopenia assessment include heterogeneity in definition and absence of standardized body composition methods used to measure SMM and muscle function tests. There is a lack of age-specific and gender-specific normative data for SMM, particularly in young children and infants. None of the studies incorporated muscle function assessment, causing potential bias and misclassification of sarcopenia. The research in childhood sarcopenia is also hampered by low study quality, limited number of outcomes-based research, and lack of longitudinal data.

CONCLUSION

Consensus needs to be reached in methodological approaches in sarcopenia diagnosis, body composition measurements, and age-appropriate muscle function tests in pediatrics. Careful considerations on growth, neurocognitive status, and factors influencing development in various clinical populations are warranted. Early identification of sarcopenia is crucial to enable targeted treatment and prevention to be carried out across the pediatric clinical populations.

Computed Tomography Evidence of Psoas Muscle Atrophy Without Concomitant Tendon Wasting in Early Sepsis

BACKGROUND

Morphomic studies have demonstrated a correlation between sarcopenia and clinical outcomes in septic patients. However, tendon morphomics has not yet been studied in this context. The purpose of the present study was to evaluate tendon morphology in septic patients through analytic morphomics. We hypothesized that morphomic analyses would reveal concomitant muscle and tendon wasting in sepsis patients. The results of this study may help to implement different rehabilitation modalities for critically ill patients.

MATERIALS AND METHODS

The volume and fat content of bilateral psoas muscles and tendons were measured on abdominal computed tomography scans of 25 ICU septic and 25 control trauma patients admitted to the University of Michigan between 2011 and 2012. Univariate and multivariate analyses were performed to determine the relationship between psoas muscle and tendon morphometric data, and the association with clinical variables such as smoking and comorbidities.

RESULTS

Average psoas muscle volume was 12.21 ± 5.6 cm³ for control patients and 9.318 ± 3.3 cm³ in septic patients (P = 0.0023). The average psoas muscle/fat ratio for septic patients was 0.0288 ± 0.071 cm³, compared with 0.0107 ± 0.008 cm³ in the control group (P = 0.075). Average tendon volume in the septic population (0.508 ± 0.191 cm³) was not different than the control cohort (0.493 ± 0.182 cm³) (P = 0.692).

CONCLUSIONS

Our results demonstrate significantly smaller psoas muscle volume in septic patients than in age-, gender-, and BMI-matched trauma patients but no demonstrable change in tendon morphology between patient groups. These findings begin to define the boundaries of clinical application within the field of morphomics.

Evaluating the "cushion effect" among children in frontal motor vehicle crashes

BACKGROUND

The "Cushion Effect," the phenomenon in which obesity protects against abdominal injury in adults in motor vehicle accidents, has not been evaluated among pediatric patients. This work evaluates the association between subcutaneous fat cross-sectional area, quantified using analytic morphomic techniques and abdominal injury.

METHODS

This retrospective study includes 119 patients aged 1 to 18years involved in frontal impact motor vehicle accidents (2003-2015) with computed tomography scans. Subcutaneous fat cross-sectional area was measured and converted to age- and gender-adjusted percentiles from population-based normative data. Multivariable analysis determined the risk of the primary outcome, Maximum Abbreviated Injury Scale (MAIS) 2+ abdominal injury, after adjusting for age, weight, seatbelt status, and impact rating.

RESULTS

MAIS 2+ abdominal injuries occurred in 20 (16.8%) of the patients. Subcutaneous fat area percentile was not significantly associated with MAIS 2+ abdominal injury on multivariable logistic regression (adjusted Odds Ratio, 0.86; 95% CI, 0.72-1.03; p=0.10).

DISCUSSION

The "cushion effect" was not apparent among pediatric frontal motor vehicle crash victims in this study. Future work is needed to investigate other analytic morphomic measures. By understanding how body composition relates to injury patterns, there is a unique opportunity to improve vehicle safety design.

LEVEL OF EVIDENCE

Prognosis Study, Level III.

Sarcopenia in Children With End-Stage Liver Disease

BACKGROUND

Sarcopenia, reflected by decreased psoas muscle surface area (PMSA), has been identified as a novel and independent predictor of wait-list mortality and outcomes in adult liver transplantation (LT). We hypothesized that children with end-stage liver disease (ESLD) would have smaller PMSA than healthy controls.

METHODS

Computer tomography images of children (ages 0 to 18 years) listed for LT in 2015 and a control group comprised 2:1 age- and gender-matched healthy pediatric trauma victims were reviewed. PMSA was determined at 2 intervertebral disc (L3/4; L4/5) levels. A subset of images was reviewed by 2 radiologists to determine interrater correlation.

RESULTS

A total of 23 children with ESLD were included, and the most prevalent diagnosis was biliary atresia (61%). On both lumbar levels, median PMSA was significantly smaller in ESLD subjects compared with the 46 healthy controls (L4/5; median total PMSA (tPMSA) 407 mm (interquartile range 339-537) versus controls 513 mm (interquartile range 437-672); P = 0.004), independent of participants' weight z scores (r = 0.01; P = 0.95). Excellent interrater correlation was seen (intraclass correlation 0.99).

CONCLUSIONS

In this retrospective pilot study, PMSA was significantly lower in children with ESLD compared with healthy age- and gender-matched controls. Because this finding was independent of growth in ESLD subjects, PMSA may represent a novel objective nutritional biomarker in children with advanced liver disease.