Does destination make a difference? Outcomes after a policy change affecting cutoff times for pre-hospital transport.

BACKGROUND: Facilitating primary triage and care at Pediatric Trauma Centers (PTCs) can improve outcomes for children after trauma. However, scene location and regional EMS regulations may result in initial evaluation occurring at non-pediatric facilities with later transportation to PTCs for definitive care. In this study, we assessed the results of a change in transport time cutoff from 30 to 45 minutes on pediatric patient outcomes. METHODS: After IRB approval, the Pediatric Trauma Database at a level 1 PTC was queried for patients seen before (January 1, 2015-December 31, 2017) and after (January 1, 2018-December 31, 2020) the implementation of a policy increasing transport cutoff time from 30 to 45 minutes. Patient outcomes were compared by transport status and ISS using generalized linear regression analysis. RESULTS: 505 patients were seen pre and 413 patients post policy changes. Both groups had similar numbers of severely injured patients (ISS ≥ 15, 64 (13%) pre and 61 (15%) post). Average transport time increased post change (pre 20 min (95% CI[18,22] min), post 29 min (95% CI[26,33] min, p = 0.0252), consistent with policy compliance. The proportion of transferred patients did not change after policy implementation (p = 0.5856), and the complications among all patients with ISS ≥ 15 did not significantly decrease (pre 75%, post 65.6%). However, those patients with ISS ≥ 15 admitted directly from the scene had a lower frequency of complications after the policy changes (pre 76%, post 59%, p = 0.0319), and in the post period transferred patients with an ISS ≥ 15 had a higher complication rate than those admitted directly from the scene (p < 0.0001). CONCLUSIONS: Direct scene admission to a PTC is associated with a lower complication profile for patients with higher ISS. Methods to ensure adherence to cutoff thresholds for EMS transport may have a positive benefit on patient outcomes. LEVEL OF EVIDENCE: IV, prognostic/epidemiological.

The hidden mortality of pediatric firearm violence.

INTRODUCTION: Firearms and motor vehicle collisions (MVC) are leading causes of mortality in children. We hypothesized that firearm injuries would have a higher mortality than MVCs in children and a higher level of resource utilization METHODS: Trauma patients <18 years old at a Level 1 pediatric trauma center sustaining gunshot wounds (GSW) or MVCs 2009-2019 were included. The primary outcome was mortality. The secondary outcome was immediate surgery. The California Department of Public Health's Overall Injury Surveillance tool was queried for patients <18 with GSW or MVC 2006-2015 to compare statewide case fatality rates (CFRs), and analyze proportions of GSWs by intent: assault, self-inflicted, and unintentional. RESULTS: Of 13,840 pediatric trauma patients at our institution, 295 GSWs (2.1%) and 4467 MVCs (32.3%) were included. Mortality was higher for GSWs (7.5% vs. 0.8%, p<0.0001). GSW patients were more likely to require immediate surgery (34.4% vs. 11.2%, p<0.0001). On multivariable analysis, GSW patients were 7.8-times more likely to die than MVC patients (OR 7.83, 95% CI 3.68-16.66, p<0.0001), adjusted for age, sex, and injury severity. Statewide, there were 10,790 pediatric GSWs with 1586 deaths (CFR 14.7%) vs. 710 deaths in 261,363 children in MVCs (CFR 0.3%, p<0.0001). The GSW CFR rose (13.4% to 16.5%, p = 0.05) while the MVC CFR decreased (0.5% to 0.2%, p<0.0001) in 2015 vs. 2006. CONCLUSION: Firearm violence in pediatric patients is significantly more lethal than MVCs and is resource intensive. The case fatality rate for pediatric firearm violence is rising. Resources must be directed at preventing pediatric firearm injuries. LEVEL OF EVIDENCE: Prognosis study, Level II.

Preliminary Evaluation of a Novel Fetal Guinea Pig Myelomeningocele Model.

INTRODUCTION: Translational models of myelomeningocele (MMC) are needed to test novel in utero interventions. An ideal animal model for MMC has locomotor function at birth and is low cost enough to allow for high throughput. The rat MMC model is limited by immature locomotor function at birth. The ovine MMC model is a costly surgical model. Guinea pigs are uniquely suited for an MMC model being a small animal model with locomotor function at birth. We aimed to develop a retinoic acid (RA) model of MMC in the guinea pig and to evaluate if pregnant guinea pigs could tolerate uterine manipulation. METHODS: Time-mated Dunkin Hartley guinea pig dams were dosed with 60 mg/kg of RA between gestation age (GA) 12 and 15 days in the development of an RA model. Fetuses were grossly evaluated for MMC lesions at Cesarean section after GA 31 days. Evaluation of the ability of pregnant guinea pig dams to tolerate uterine surgical intervention was performed by hysterotomy of a separated group of time-mated guinea pigs at GA 45, 50, and 55. RESULTS: Forty-two pregnant guinea pigs were dosed with RA, with a total of 189 fetuses. The fetal demise rate was 38% (n = 71). A total of 118 fetuses were viable, 83% (n = 98) were normal fetuses, 8% (n = 10) had a neural tube defect, and 8% (n = 10) had a hematoma or other anomalies. No fetuses developed an MMC defect. None of the fetuses that underwent hysterotomy survived to term. CONCLUSION: RA dosed at 60 mg/kg in guinea pigs between GA 12 and 15 did not result in MMC. Dunkin Hartley guinea pigs did not tolerate a hysterotomy near term in our surgical model. Further work is needed to determine if MMC can be induced in guinea pigs with alternate RA dosing.

Total gastrectomy with delayed Hunt-Lawrence pouch reconstruction for neonatal gastric perforation presenting with hematemesis.

The differential for neonatal hematoma sis ranges from benign etiologies to life-threatening emergencies. Neonatal gastric perforation is a rare cause of neonatal hematoma sis but is a deadly condition, requiring prompt diagnosis and treatment. The etiology is usually related to conditions predisposing to over distension of the stomach, such as positive pressure ventilation or distal obstruction, but in some cases cannot be determined. Patients generally present with abdominal distension and respiratory distress. We present a case of a 1-day old term baby girl who developed sudden onset hematoma sis and clinical deterioration, who was found to have a large proximal gastric perforation requiring emergent total gastrectomy with delayed reconstruction.

In utero treatment of myelomeningocele with placental mesenchymal stromal cells - Selection of an optimal cell line in preparation for clinical trials.

BACKGROUND: We determined whether in vitro potency assays inform which placental mesenchymal stromal cell (PMSC) lines produce high rates of ambulation following in utero treatment of myelomeningocele in an ovine model. METHODS: PMSC lines were created following explant culture of three early-gestation human placentas. In vitro neuroprotection was assessed with a neuronal apoptosis model. In vivo, myelomeningocele defects were created in 28 fetuses and repaired with PMSCs at 3 × 105 cells/cm2 of scaffold from Line A (n = 6), Line B (n = 7) and Line C (n = 5) and compared to no PMSCs (n = 10). Ambulation was scored as ≥13 on the Sheep Locomotor Rating Scale. RESULTS: In vitro, Line A and B had higher neuroprotective capability than no PMSCs (1.7 and 1.8 respectively vs 1, p = 0.02, ANOVA). In vivo, Line A and B had higher large neuron densities than no PMSCs (25.2 and 27.9 respectively vs 4.8, p = 0.03, ANOVA). Line C did not have higher neuroprotection or larger neuron density than no PMSCs. In vivo, Line A and B had ambulation rates of 83% and 71%, respectively, compared to 60% with Line C and 20% with no PMSCs. CONCLUSION: The in vitro neuroprotection assay will facilitate selection of optimal PMSC lines for clinical use. LEVEL OF EVIDENCE: n/a. TYPE OF STUDY: Basic science.

Spinal Angulation: A Limitation of the Fetal Lamb Model of Myelomeningocele.

INTRODUCTION: The surgically induced fetal lamb model is the most commonly used large animal model of myelomeningocele (MMC) but is subject to variation due to surgical technique during defect creation. MATERIAL AND METHODS: Thirty-one fetal lambs underwent creation of the MMC defect, followed by defect repair with either an extracellular matrix (ECM) patch (n = 10) or ECM seeded with placental mesenchymal stromal cells (n = 21). Postnatal hindlimb function was assessed using the Sheep Locomotor Rating (SLR) scale. Postmortem magnetic resonance imaging of the lumbar spine was used to measure the level and degree of spinal angulation, as well as cross-sectional area of remaining vertebral bone. RESULTS: Median level of angulation was between the 2nd and 3rd lumbar vertebrae, with a median angle of 24.3 degrees (interquartile range 16.2-35.3). There was a negative correlation between angulation degree and SLR (r = -0.44, p = 0.013). Degree of angulation also negatively correlated with the normalized cross-sectional area of remaining vertebral bone (r = -0.75, p < 0.0001). DISCUSSION: Surgical creation of fetal MMC leads to varying severity of spinal angulation in the ovine model, which affects postnatal functional outcomes. Postnatal assessment of spinal angulation aids in standardization of the surgical model of fetal MMC repair.

High density placental mesenchymal stromal cells provide neuronal preservation and improve motor function following in utero treatment of ovine myelomeningocele.

PURPOSE: The purpose of this study was to determine whether seeding density of placental mesenchymal stromal cells (PMSCs) on extracellular matrix (ECM) during in utero repair of myelomeningocele (MMC) affects motor function and neuronal preservation in the ovine model. METHODS: MMC defects were surgically created in 33 fetuses and repaired following randomization into four treatment groups: ECM only (n = 10), PMSC-ECM (42 K cells/cm2) (n = 8), PMSC-ECM (167 K cells/cm2) (n = 7), or PMSC-ECM (250-300 K cells/cm2) (n = 8). Motor function was evaluated using the Sheep Locomotor Rating Scale (SLR). Serial sections of the lumbar spinal cord were analyzed by measuring their cross-sectional areas which were then normalized to normal lambs. Large neurons (LN, diameter 30-70 µm) were counted manually and density calculated per mm2 gray matter. RESULTS: Lambs treated with PMSCs at any density had a higher median SLR score (15 [IQR 13.5-15]) than ECM alone (6.5 [IQR 4-12.75], p = 0.036). Cross-sectional areas of spinal cord and gray matter were highest in the PMSC-ECM (167 K/cm2) group (p = 0.002 and 0.006, respectively). LN density was highest in the greatest density PMSC-ECM (250-300 K/cm2) group (p = 0.045) which positively correlated with SLR score (r = 0.807, p < 0.0001). CONCLUSIONS: Fetal repair of myelomeningocele with high density PMSC-ECM resulted in increased large neuron density, which strongly correlated with improved motor function. TYPE OF STUDY: Basic science. LEVEL OF EVIDENCE: N/A.

Epidemiology of Hirschsprung disease in California from 1995 to 2013.

PURPOSE: This study seeks to update current epidemiology of Hirschsprung disease (HD) in California. METHODS: Using data from the California Office of Statewide Health Planning and Development Linked Birth (1995-2012) and Patient Discharge Databases (1995-2013), patients from either dataset with an ICD-9 diagnosis code of HD (751.3) or procedure code of Soave (48.41), Duhamel (48.65), or Swenson/other pull-through (48.49) were included. Patients > age 18 during their first admission were excluded. RESULTS: Of 9.3 million births, 2,464 patients were identified. Incidence was 2.2 cases/10,000 live births, with rates peaking at 2.9/10,000 births in 2002. Incidence was highest among African American (4.1/10,000) and Asian/Pacific Islander (2.5/10,000) births. Most were male (n = 1652, 67.1%). Sixty patients (2.4%) had Down syndrome. The median gestational age at birth was 38 weeks 6 days (interquartile range [IQR] 37 weeks 1 day-40 weeks 1 day). Mortality during the first year of life was 1.7%. Median age at death was 14.5 days (IQR 0-113 days). CONCLUSION: This is one of the largest population-based studies of HD. In California, the incidence of HD is stable, risk is highest among African American children, and the mortality rate is < 2%.

Fetal Surgery for Myelomeningocele: A Systematic Review and Meta-Analysis of Outcomes in Fetoscopic versus Open Repair.

BACKGROUND/OBJECTIVES: The Management of Myelomeningocele (MMC) Study (MOMS) showed that prenatal repair of MMC resulted in improved neurological outcomes but was associated with high rates of obstetrical complications. This study compares outcomes of open and fetoscopic MMC repair. DATA SOURCES: PubMed and Embase studies reporting outcomes of fetal MMC repair published since the completion of the MOMS. RESULTS: We analyzed 11 studies and found no difference in mortality or the rate of shunt placement for hydrocephalus. Percutaneous fetoscopic repair was associated with higher rates of premature rupture of membranes (91 vs. 36%, p < 0.01) and preterm birth (96 vs. 81%, p = 0.04) compared to open repair, whereas fetoscopic repair via maternal laparotomy reduced preterm birth. The rate of dehiscence and leakage from the MMC repair site was higher after both types of fetoscopic surgery (30 vs. 7%, p < 0.01), while the rate of uterine dehiscence was higher after open repair (11 vs. 0%, p < 0.01). DISCUSSION: Fetoscopic repair is a promising alternative to open fetal MMC repair with a lower risk of uterine dehiscence; however, fetoscopic techniques should be optimized to overcome the high rate of dehiscence and leakage at the MMC repair site. A fetoscopic approach via maternal laparotomy reduces the risk of preterm birth.

Lessons from the Barn to the Operating Suite: A Comprehensive Review of Animal Models for Fetal Surgery.

The International Fetal Medicine and Surgery Society was created in 1982 and proposed guidelines for fetal interventions that required demonstrations of the safety and feasibility of intended interventions in animal models prior to application in humans. Because of their short gestation and low cost, small animal models are useful in early investigation of fetal strategies. However, owing to the anatomic and physiologic differences between small animals and humans, repeated studies in large animal models are usually needed to facilitate translation to humans. Ovine (sheep) models have been used the most extensively to study the pathophysiology of congenital abnormalities and to develop techniques for fetal interventions. However, nonhuman primates have uterine and placental structures that most closely resemble those of humans. Thus, the nonhuman primate is the ideal model to develop surgical and anesthetic techniques that minimize obstetrical complications.

Fetal surgical repair with placenta-derived mesenchymal stromal cell engineered patch in a rodent model of myelomeningocele.

PURPOSE: The purpose of this study is to determine the feasibility of fetal surgical repair of myelomeningocele (MMC) in a rodent model using human placental mesenchymal stromal cells (PMSCs) seeded onto extracellular matrix (ECM) and to characterize the resulting changes in spinal cord tissue. METHODS: Fetal rodents with retinoic acid (RA) induced MMC underwent surgical repair of the MMC defect using an ECM patch on embryonic age (EA) 19 and were collected via caesarean section on EA 21. Various seeding densities of PMSC-ECM and ECM only controls were evaluated. Cross-sectional compression (width/height) and apoptotic cell density of the lumbosacral spinal cord were analyzed. RESULTS: 67 dams treated with 40mg/kg of RA resulted in 352 pups with MMC defects. 121 pups underwent MMC repair, and 105 (86.8%) survived to term. Unrepaired MMC pups had significantly greater cord compression and apoptotic cell density compared to normal non-MMC pups. Pups treated with PMSC-ECM had significantly less cord compression and demonstrated a trend towards decreased apoptotic cell density compared to pups treated with ECM only. CONCLUSION: Surgical repair of MMC with a PMSC-seeded ECM disc is feasible with a postoperative survival rate of 86.8%. Fetal rodents repaired with PMSC-ECM have significantly less cord deformity and decreased histological evidence of apoptosis compared to ECM only controls.

Placental mesenchymal stromal cells seeded on clinical grade extracellular matrix improve ambulation in ovine myelomeningocele.

PURPOSE: The purpose of this study was to investigate the effects of placental mesenchymal stromal cells (PMSCs) seeded on a clinical grade porcine small intestinal submucosa (SIS)-derived extracellular matrix (ECM) on hindlimb motor function in an ovine fetal repair model of myelomeningocele (MMC). METHODS: MMC defects were surgically created in 21 fetuses at median gestational age 78 (range 76-83) days. Fetuses were randomly assigned to repair 25days later with ECM only or PMSC-ECM. Surviving fetuses were delivered at term. Motor function was evaluated using the Sheep Locomotor Rating (SLR) scale (0-15). Histologic analysis of the spinal cord (SC) was completed. RESULTS: Fetal viability was 71%. 5 of 8 (63%) lambs repaired with PMSC-ECM ambulated independently versus only 1 of 6 (17%) repaired with ECM only (p=0.04, χ2 test). SLR scores and large neuron densities were higher in the PMSC-ECM group. The cross-sectional areas of the SC and the gray matter were equally preserved. CONCLUSIONS: Fetal repair of MMC with PMSCs seeded on SIS-ECM improves hindlimb motor function in lambs. Using ECM helps to preserve the architecture of the SC, but adding PMSCs improves the lamb's ability to walk and increases large neuron density. Clinical studies are needed to show benefits in humans. LEVELS OF EVIDENCE/TYPE OF STUDY: Basic Science.

Potential clinical applications of placental stem cells for use in fetal therapy of birth defects.

Placental stem cells are of growing interest for a variety of clinical applications due to their multipotency and ready availability from otherwise frequently discarded biomaterial. Stem cells derived from the placenta have been investigated in a number of disease processes, including wound healing, ischemic heart disease, autoimmune disorders, and chronic lung or liver injury. Fetal intervention for structural congenital defects, such as spina bifida, has rapidly progressed as a field due to advances in maternal-fetal medicine and improving surgical techniques. In utero treatment of structural, as well as non-structural, congenital disorders with cell-based therapies is of particular interest given the immunologic immaturity and immunotolerant environment of the developing fetus. A comprehensive literature review was performed to assess the potential utilization of placenta-derived stem cells for in utero treatment of congenital disorders. Most studies are still in the preclinical phase, utilizing animal models of common congenital disorders. Future research endeavors may include autologous transplantation, gene transfers, induced pluripotent stem cells, or cell-free therapies derived from the stem cell secretome. Though much work still needs to be done, placental stem cells are a promising therapeutic agent for fetal intervention for congenital disease.

New directions in fetal surgery for myelomeningocele.

The treatment of children with myelomeningocele (MMC) has improved over time, from supportive management to early postnatal closure to prenatal repair of the defect. The Management of Myelomeningocele Study (MOMS) showed that prenatal repair of MMC resulted in improved neurological outcomes compared to postnatal closure. Follow-up studies showed that prenatal repair was, as with any other fetal intervention, associated with higher rates of obstetrical complications. There was no significant difference in urological outcomes. Long-term follow-up of ambulatory status, executive functioning, and urological outcomes is needed to determine the durable effects of fetal MMC repair on mobility, functional independence, and the prevalence of renal insufficiency in patients with MMC who survive to adulthood. The future of fetal MMC repair consists of developing strategies to reduce maternal morbidity and improve infant outcomes. Fetoscopic MMC repair has been suggested as an alternative to open repair that may reduce obstetrical complications and the need for cesarean delivery in subsequent pregnancies. Translational research using mesenchymal stromal cells to augment fetal repair of ovine MMC has shown improvement in motor function.