Chondroid lipoma: multimodality imaging in a 9-year-old female.

Chondroid lipomas are rare, benign lipomatous tumors that occur most frequently in adults during the fourth decade of life. While a female predominance was observed in the initial series of 20 cases described in 1993, the subsequent 49 reported cases do not support a strong gender predilection. We report a case of a chondroid lipoma presenting in a 9-year-old female as a painless, enlarging, left gluteal mass. This is the second case to be reported in the first decade of life and the fourth pediatric case reported in the literature (age < 21). We review the imaging and pathology findings as well as present a comprehensive review of the current literature.

Optical properties of human amniotic fluid: implications for videofetoscopic surgery.

OBJECTIVE: Videofetoscopy typically demands the substitution of oft-turbid amniotic fluid with clear crystalloid. This maneuver can be cumbersome and may lead to complications. We sought to determine the optical properties of the amniotic fluid, as a pre-requisite for optimizing video image processing during videofetoscopy and eventually avoid amniotic fluid replacement. METHODS: Human amniotic fluid samples (n = 21) were procured at 19-36 weeks of gestation. Optical refraction and reflection indices were recorded as percentages of light transmission through the fluid using an integrated spectrometer covering wavelengths of 400-950 nm, with 1.0 nm resolution. Statistical analysis was by one-way ANOVA (p < 0.05). RESULTS: Peak optical refraction fell within a relatively limited window of the near-infrared spectrum, at 848.1 +/- 52.3 nm, regardless of gestational age or overall light absorbance. Within the visible spectrum, transmission was highest at the highest wavelengths. A statistically significant inverse relationship existed between gestational age and overall light transmission. Light reflection was negligible in all samples. CONCLUSIONS: Light transmission through amniotic fluid is optimal in the near-infrared spectrum and at the highest visible wavelengths, regardless of gestational age. Overall light transmission through amniotic fluid decreases throughout gestation. The light source and camera of videofetoscopy systems should be designed accordingly, possibly obviating the need for routine intraoperative amniotic fluid exchange.

Early versus late surgical management of complicated appendicitis in children: A statewide database analysis with one-year follow-up.

BACKGROUND: Complicated appendicitis is common in children, yet the timing of surgical management remains controversial. Some support initial antibiotics with delayed operation whereas others support immediate operation. While a few randomized trials have evaluated this question, they have been small, single-center trials with limited follow-up. We present a database analysis of outcomes in early versus late surgical management of complicated appendicitis with one-year follow-up. METHODS: We conducted a retrospective review of children with complicated appendicitis presenting between 2000 and 2013, utilizing a New York State database. We compare children undergoing later versus early appendectomy with a primary outcome measure of any complication within one year as determined from ICD-9 codes. RESULTS: 8840 children were included in the analysis, 7708 of whom underwent early appendectomy. Patients with late appendectomy were significantly more likely to have at least one complication when compared to those undergoing early appendectomy (34.6% vs 26.7%, p<0.01). CONCLUSIONS: We present the first population-level study evaluating early versus late appendectomy in children with complicated appendicitis with a one-year follow-up period. Children undergoing late appendectomy were more likely to have a complication than those undergoing early appendectomy. These data corroborated previous studies supporting early operative management. LEVEL OF EVIDENCE: This study provides level III evidence of a treatment study.

A comparative analysis of cartilage engineered from different perinatal mesenchymal progenitor cells.

We sought to compare engineered cartilaginous constructs derived from different perinatal mesenchymal progenitor cell (MPC) sources. Ovine MPCs isolated from amniotic fluid (AF, n = 8), neonatal bone marrow (BM, n = 6), and preterm umbilical cord blood (CB, n = 12) were expanded and comparably seeded onto synthetic scaffolds. Constructs were maintained in chondrogenic media containing transforming growth factor-beta. After 12-15 weeks, specimens were compared with native fetal hyaline and elastic cartilage by gross inspection, histology, immunohistochemistry, and quantitative extracellular matrix (ECM) assays. MPCs from AF proliferated significantly faster ex vivo when compared to MPCs from the other sources. Chondrogenic differentiation was evident in all groups, as shown by toluidine blue staining and expression of aggrecan, cartilage proteoglycan link protein, and collagen type II. Quantitatively, all engineered specimens had significantly lower levels of glycosaminoglycans than native hyaline cartilage. Elastin levels in AF-based constructs (156.0 +/- 120.4 microg/mg) were comparable to that of native elastic cartilage (235.8 +/- 54.2 microg/mg), both of which were significantly higher than in BM- and CB-based specimens. We conclude that the ECM profile of cartilage engineered from perinatal MPCs is highly dependent on cell source. ECM peculiarities should be considered when designing the optimal cartilaginous bioprosthesis for use in perinatal surgical reconstruction.

Maintaining low transfusion and angioembolization rates in the age of nonoperative management of pediatric blunt splenic injury.

Nonoperative management of hemodynamically stable blunt splenic injury (BSI) is the gold standard in children. Recent studies from nonpediatric surgery-specialized trauma centers have demonstrated a rise in transfusion and angioembolization associated with decreased splenectomy rates. We investigate the rate of splenectomy and nonsurgical interventions (angioembolization, blood transfusion) for BSI in a pediatric surgery-specialized trauma center. We conducted a retrospective review of children (0 to 18 years) treated between September 2001 and September 2011 at a children's hospital. Analyzed data included presenting vital signs, nadir hemoglobin, splenic injury grade, Revised Trauma Score, and Injury Severity Score (ISS). Measured outcomes included transfusion, angioembolization, and splenectomy rates. The study period was divided into three time periods to identify possible trends and compared with national averages. There were 180 patients, 91 with multiple injuries (50.6%) and 89 (49.4%) with isolated BSI. Seventy-six per cent of patients were male, average age was 12.8 years, and average ISS was 14.7. The overall splenectomy rate was 1.7 per cent (1.1% for isolated splenic injury). Our angioembolization rate was 0.6 per cent compared with 7.4 to 16 per cent nationally. Our transfusion rate was 14.4 per cent overall and 5.6 per cent for isolated splenic injury compared with 9.5 to 24.9 per cent nationally. Intervention rates remained unchanged over the study period. Splenectomy rates have remained low at our institution without an increase in angioembolization or transfusion. Children with splenic injuries treated at dedicated pediatric hospitals can be successfully managed nonoperatively without angioembolization or blood transfusion.

Use of white blood cell count and negative appendectomy rate.

BACKGROUND: Despite increased utilization of laboratory, radiologic imaging, and scoring systems, negative appendectomy (NA) rates in children remain above 3% nationwide. We reviewed the clinical data of patients undergoing appendectomy to further reduce our NA rate. METHODS: A retrospective review was conducted of all appendectomies performed for suspected appendicitis at a tertiary children's hospital during a 42-month period. Preoperative clinical, laboratory, and radiographic data were collected. Variables absent or normal in more than half of NAs were further analyzed. Receiver operating characteristic curves were constructed for continuous variables by using appropriate cutoff points to determine sensitivity and false-positive rates. The results were validated by analyzing the 12 months immediately after the establishment of these rules. RESULTS: Of 847 appendectomies performed, 22 (2.6%) had a pathologically normal appendix. The only variables found to be normal in more than half of NAs were white blood cell (WBC) count (89%) and neutrophil count (79%). A receiver operating characteristic curve indicates that using WBC cutoffs of 9000 and 8000 per µL yielded sensitivities of 92% and 95%, respectively, and reduction in NA rates by 77% and 36%, respectively. Results observed in the subsequent 12 months confirmed these expected sensitivities and specificities. CONCLUSIONS: Absence of an elevated WBC count is a risk factor for NA. Withholding appendectomy for WBC counts <9000 and 8000 per µL reduces the NA rate to 0.6% and 1.2%, respectively. Missed true appendicitis in patients with normal WBC counts can be mitigated by a trial of observation in those presenting with early symptom onset.

Individualized image display improves performance in laparoscopic surgery.

BACKGROUND: Laparoscopic surgery has made great advances over the years, but it is still dependent on a single viewpoint. This single-lens system impedes multitasking and may provide suboptimal views of the operative field. We have previously developed a prototype of interactive laparoscopic image display to enable individualized manipulation of the displayed image by each member of the operating team. The current study examines whether the concept of individualized image display improves performance during laparoscopic surgery. MATERIALS AND METHODS: Individualized display of the endoscopic image was implemented in vitro using two cameras, independently manipulated by each operator, in a Fundamental of Laparoscopic Surgery (Society of American Gastrointestinal and Endoscopic Surgeons) endotrainer model. The standardized bead transfer and endoloop tasks were adapted to a two-operator exercise. Each team of two was paired by experience level (novice or expert) and was timed twice: once while using a single camera (control) and once using two cameras (individualized image). RESULTS: In total, 20 medical students, residents, and attending surgeons were paired in various combinations. Bead transfer times for the individualized image experiment were significantly shorter in the expert group (61.8 ± 14.8% of control, P=.002). Endoloop task performance time was significantly decreased in both novices (80.3 ± 44.4%, P=.04) and experts (69.5 ± 12.9%, P=.001) using the two-camera set-up. CONCLUSIONS: Many advances in laparoscopic image display have led to an incremental improvement in performance. They have been most beneficial to novices, as experts have learned to overcome the shortcomings of laparoscopy. Using a validated tool of laparoscopic training, we have shown that efficiency is improved with the use of an individualized image display and that this effect is more pronounced in experts. The concept of individual image manipulation and display will be further developed into a hands-free, intuitive system and must be validated in a clinical setting.

Amniotic mesenchymal stem cells enhance normal fetal wound healing.

Fetal wound healing involves minimal inflammation and limited scarring. Its mechanisms, which remain to be fully elucidated, hold valuable clues for wound healing modulation and the development of regenerative strategies. We sought to determine whether fetal wound healing includes a hitherto unrecognized cellular component. Two sets of fetal lambs underwent consecutive experiments at midgestation. First, fetuses received an intra-amniotic infusion of labeled autologous amniotic mesenchymal stem cells (aMSCs), in parallel to different surgical manipulations. Subsequently, fetuses underwent creation of 2 symmetrical, size-matched skin wounds, both encased by a titanium chamber. One of the chambers was left open and the other covered with a semipermeable membrane that allowed for passage of water and all molecules, but not any cells. Survivors from both experiments had their wounds analyzed at different time points before term. Labeled aMSCs were documented in all concurrent surgical wounds. Covered wounds showed a significantly slower healing rate than open wounds. Paired comparisons indicated significantly lower elastin levels in covered wounds at the mid time points, with no significant differences in collagen levels. No significant changes in hyaluronic acid levels were detected between the wound types. Immunohistochemistry for substance P was positive in both open and covered wounds. We conclude that fetal wound healing encompasses an autologous yet exogenous cellular component in naturally occurring aMSCs. Although seemingly not absolutely essential to the healing process, amniotic cells expedite wound closure and enhance its extracellular matrix profile. Further scrutiny into translational implications of this finding is warranted.

Preclinical regulatory validation of an engineered diaphragmatic tendon made with amniotic mesenchymal stem cells.

PURPOSE: Under a Food and Drug Administration directive, we examined definite long-term safety and efficacy aspects of an engineered diaphragmatic tendon graft as a regulatory prerequisite for clinical trials. METHODS: Newborn lambs (N = 27) underwent partial diaphragmatic replacement with a Teflon patch, a composite acellular bioprosthesis, or the same bioprosthesis seeded with autologous amniotic mesenchymal stem cells processed under Good Manufacturing Practice guidelines. Multiple safety and efficacy analyses were performed at different time points up to 14 months of age (ovine adulthood). RESULTS: There was no mortality. None of the blood tests or full body autopsy specimens showed any abnormality. There was a significantly higher failure rate in animals that received an acellular bioprosthetic graft vs an engineered graft, with no significant differences between Teflon and acellular bioprosthetic implants. Tensile strength and total collagen levels were significantly higher in engineered grafts than in acellular bioprosthetic grafts. On histology, lysozyme and myeloperoxidase stainings were unremarkable in all grafts. CONCLUSIONS: Diaphragmatic repair with a clinically viable autologous tendon engineered with amniotic mesenchymal stem cells leads to improved outcomes when compared with an equivalent acellular bioprosthesis, with no local or systemic adverse effects. Clinical trials of engineered diaphragmatic repair appear practicable within regulatory guidelines.

Chest wall repair with engineered fetal bone grafts: an efficacy analysis in an autologous leporine model.

PURPOSE: We sought to compare the efficacy of engineered fetal bone grafts with acellular constructs in an autologous model of chest wall repair. METHODS: Rabbits (n = 10) with a full-thickness sternal defect were equally divided in 2 groups based on how the defect was repaired, namely, either with an autologous bone construct engineered with amniotic mesenchymal stem cells on a nanofibrous scaffold or a size-matched identical scaffold with no cells. Animals were killed at comparable time-points 18 to 20 weeks postimplantation for multiple analyses. RESULTS: Gross evidence of nonunion confirmed by micro-computed tomography scanning was present in 3 (60%) of 5 of the acellular implants but in no engineered grafts. Histology confirmed the presence of bone in both types of repair, albeit seemingly less robust in the acellular grafts. Mineral density in vivo was significantly higher in engineered grafts than in acellular ones, with more variability among the latter. There was no difference in alkaline phosphatase activity between the groups. CONCLUSIONS: Chest wall repair with an autologous osseous graft engineered with amniotic mesenchymal stem cells leads to improved and more consistent outcomes in the midterm when compared with an equivalent acellular prosthetic repair in a leporine model. Amniotic fluid-derived engineered bone may become a practical alternative for perinatal chest wall reconstruction.

Structural and biomechanical characteristics of the diaphragmatic tendon in infancy and childhood: an initial analysis.

BACKGROUND: Engineered tendon grafts have been shown, experimentally, to be promising alternatives for partial diaphragmatic replacement. This study was aimed at determining the cellularity, extracellular matrix composition, and biomechanical characteristics of the diaphragmatic tendon in infants and children to be used as a reference for proper diaphragmatic graft engineering. METHODS: The left diaphragmatic tendon was procured at autopsy from 13 patients divided into 2 groups. Group I (n = 9) consisted of newborns and infants. Group II (n = 4) consisted of children and adolescents. Samples underwent quantitative assays for total DNA, glycosaminoglycans, collagen, and elastin contents. Biomechanical measurements included modular and ultimate tensile strength analyses. Statistical comparisons were by the 2-sample Student's t test. RESULTS: Group I showed significantly higher levels of total DNA, glycosaminoglycans, collagen, and elastin than group II. Conversely, group II tended to have higher modular and ultimate tensile strengths. CONCLUSIONS: In neonates and infants, the diaphragmatic tendon has increased cell density and higher levels of major extracellular matrix components than in older children, in whom the diaphragmatic tendon tends to have higher tensile strength. Engineered diaphragmatic constructs should be tailored to the distinct anatomical, functional, and biomechanical characteristics of the diaphragmatic tendon at different age groups.

Differential risk for neonatal surgical airway intervention in prenatally diagnosed neck masses.

PURPOSE: We aimed to identify risk factors for neonatal surgical airway intervention among fetuses with prenatally diagnosed cervical masses. METHODS: An 8-year retrospective review identified 23 consecutive patients with a prenatal diagnosis of a neck mass, managed at a single tertiary center. Variables analyzed included anticipated diagnosis, extent of the mass, need for any surgical airway intervention in the neonatal period, final histopathology data, and survival. Statistical analysis was based on the Fisher and Fisher-Freeman-Halton exact tests (significance set at P < or = .05) and exact 95% confidence intervals for risk differences. RESULTS: Eight patients underwent termination of pregnancy or were lost to follow-up. The imaging-based prenatal diagnosis was confirmed postnatally in 93% (14/15) of the remaining patients. Final diagnoses included lymphatic malformation (8), teratoma (6), and esophageal duplication (1). Teratomas were associated with a significantly higher risk for neonatal airway intervention than lymphatic malformations (67% vs 11%, P = .02). The majority of such procedures were performed under ex utero intrapartum treatment. Survival was 93% (14/15). CONCLUSIONS: Cervical teratomas are significantly more likely to demand surgical airway intervention in the neonate, typically under ex utero intrapartum treatment, than cervical lymphatic malformations. These findings should be considered in the prenatal counseling for fetal cervical masses.

Sternal repair with bone grafts engineered from amniotic mesenchymal stem cells.

PURPOSE: We aimed at determining whether osseous grafts engineered from amniotic mesenchymal stem cells (aMSCs) could be used in postnatal sternal repair. METHODS: Leporine aMSCs were isolated, identified, transfected with green fluorescent protein (GFP), expanded, and seeded onto biodegradable electrospun nanofibrous scaffolds (n = 6). Constructs were dynamically maintained in an osteogenic medium and equally divided into 2 groups with respect to time in vitro as follows: 14.6 or 33.9 weeks. They were then used to repair full-thickness sternal defects spanning 2 to 3 intercostal spaces in allogeneic kits (n = 6). Grafts were submitted to multiple analyses 2 months thereafter. RESULTS: Chest roentgenograms showed defect closure in all animals, confirmed at necropsy. Graft density as assessed by microcomputed tomographic scans increased significantly in vivo, yet there were no differences in mineralization by extracellular calcium measurements preimplantation and postimplantation. There was a borderline increase in alkaline phosphatase activity in vivo, suggesting ongoing graft remodeling. Histologically, implants contained GFP-positive cells and few mononuclear infiltrates. There were no differences between the 2 construct groups in any comparison. CONCLUSIONS: Engineered osseous grafts derived from amniotic mesenchymal stem cells may become a viable alternative for sternal repair. The amniotic fluid can be a practical cell source for engineered chest wall reconstruction.

Preclinical regulatory validation of a 3-stage amniotic mesenchymal stem cell manufacturing protocol.

PURPOSE: Because of the 4 to 6-month interval between a diagnostic amniocentesis and birth, clinical application of amniotic mesenchymal stem cell (AMSC)-based therapies demands a 3-stage cell manufacturing process, including isolation/primary expansion, cryopreservation, and thawing/secondary expansion. We sought to determine the feasibility and cell yield of such a staged cell manufacturing process, within regulatory guidelines. METHODS: Human AMSCs isolated from diagnostic amniocentesis samples (n = 11) were processed under Food and Drug Administration-accredited good manufacturing practice. Expanded cells were characterized by flow cytometry and cryopreserved for 3 to 5 months. Cell release criteria included more than 90% CD29+, CD73+, and CD44+; less than 5% CD34+ and CD45+; negative mycoplasma quantitative polymerase chain reaction (QPCR) and endotoxin assay; and at least 70% viability. RESULTS: Isolation and ample expansion of AMSCs was achieved in 54.5% (6/11) of the samples. Early processing and at least a 2-mL sample were necessary for reliable cell manufacturing. Cell yield before cryopreservation was 223.2 +/- 65.4 x 10(6) cells (44.6-fold expansion), plus a 14.7 x 10(6)-cell backup, after 36.3 +/- 7.8 days. Cell viability postthaw was 88%. Expanded cells maintained a multipotent mesenchymal progenitor profile. CONCLUSIONS: Human amniotic mesenchymal stem cells can be manufactured in large numbers from diagnostic amniocentesis, by an accredited staged processing, under definite procurement guidelines. These data further support the viability of clinical trials of amniotic mesenchymal stem cell-based therapies.

Isolation of mesenchymal stem cells from amniotic fluid and placenta.

Diverse progenitor cell populations, including mesenchymal, hematopoietic, trophoblastic, and possibly more primitive stem cells can be isolated from the amniotic fluid and the placenta. At least some of the amniotic and placental cells share a common origin, namely the inner cell mass of the morula. Indeed, most types of progenitor cells that can be isolated from these two sources share many characteristics. This unit will focus solely on the mesenchymal stem cells, the most abundant progenitor cell population found therein and, unlike some of the other stem cell types, present all through gestation. Protocols for isolation, expansion, freezing, and thawing of these cells are presented. Preference is given to the simplest methods available for any given procedure.