Needle Microcores: Can They Pose an Occlusive Threat with Nonparticulate Injections?

SUMMARY

The incidence of vascular occlusion injuries has risen substantially along with the increasing popularity of cosmetic injectables. Among these occurrences, instances of soft-tissue ischemic events following the injection of nonparticulate solutions, such as botulinum, represent an enigmatic etiology that has yet to be fully understood. One hypothesized mechanism of injury underlying these events relates to the accidental capture and intravascular ejection of needle microcores, defined as submillimeter tissue fragments trapped by the beveled lumen of a needle during conventional injections. To test this hypothesis, the authors conducted a cytologic evaluation of dermal remnants incidentally captured by 31-G tuberculin needles following repeated injections into postrhytidectomy skin fragments. Their findings revealed the presence of dermal tissue microcores ranging from 100 to 275 μm in diameter with an overall microcoring incidence of 0.7%. These findings confirm the ability of ultrafine needles, commonly used in botulinum injections, to produce tissue microcores that may serve as causative agents of vascular occlusion with nonparticulate solutions. Awareness of this mechanism of injury may be of benefit in the early recognition and management of these rare occurrences.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Solitary Intrascrotal Plexiform Neurofibroma in a 10-Year-Old Male

Intrascrotal neurofibromas are extensive tumors that grow from peripheral nerves within the scrotum and are exceedingly rare among the benign extratesticular tumors. Though the risk is low, potential for malignancy and patient discomfort make diagnosis and surgical evaluation imperative. Pediatric neurofibromas are typically only associated with neurofibromatosis type 1. However, herein, we describe a rare case of a benign, intrascrotal plexiform neurofibroma in a 10-year-old male who lacks any stigmata associated with this genetic disorder. Diagnostic and surgical challenges as well as histopathological findings are discussed.

Twin Reversed Arterial Perfusion Sequence (TRAPS): An Illustrative Series of 13 Cases

Twin reversed-arterial-perfusion sequence (TRAPS) is a rare and severe complication of monochorionic twin pregnancies. It usually occurs in the setting of monochorionic placentation, when the heart of a normal appearing twin serves as the pump for one or more dysmorphic twins whose head, thoracic organs, and upper extremities do not fully develop or do not develop at all and thus lack cardiac activity. Anomalous vascular placental architecture causes a shift in arterial flow towards the acardiac twin(s). The exact physiopathologic mechanisms that lead to this devastating phenomenon are not well known. We reviewed the maternal history and the surgical pathology reports of the fetuses and placentas of 13 different cases of TRAPS that were collected in a 23-year study period at a single institution. Herein we summarize the characteristic findings and illustrate specific mechanical feto-placental circulation issues that appear to be instrumental in the development of TRAPS.

An animal model of necrotizing enterocolitis (NEC) in preterm rabbits

Creation of an animal model of necrotizing enterocolitis (NEC) allowing adjustment of severity and potential recoverability is needed to study effectiveness of prevention and treatment strategies. This study describes a novel model in preterm rabbits capable of adjusting severity of NEC-like histologic changes. Rabbit pups (n = 151) were delivered by cesarean section 2 days preterm. In the treatment groups, tissue adhesive was applied to anal openings to simulate the poor intestinal function and dysmotility of preterm neonates. Pups were placed into five groups: 3INT (3 day intermittent block), 4INT (4 day intermittent block), 3COM (3 day complete block), 4COM (4 day complete block), based on differences in type of anal blockage and day of life sacrificed. The fifth group, 4CON, was comprised of a control arm (n = 28) without anal block, with sacrifice of subjects on day 4. All pups were gavage fed with formula contaminated with Enterobacter cloacae, ranitidine, and indomethacin. Following sacrifice, the intestines were harvested for pathologic evidence of NEC. A blinded pathologist graded histologic changes consistent with NEC using a grading scale 0-4 with 4 being most severe. Fifty-seven pups (57/123) (46%) in the research arm survived to sacrifice, compared to 26/28 (93%) in the control arm of the investigation, p < 0.0001. The incidence and severity of NEC-like damage increased with the duration and completeness of the anal blockage. 44/57 (77%) of survivors revealed various degrees of NEC-like damage to large and small bowel, and 3/26 (12%) exhibited early NEC-like mucosal injury in the research and control arms, respectively. This animal model produces NEC-like pathologic changes in both small and large intestine in preterm rabbits. Because incidence and severity of damage increases with duration and completeness of intestinal dysmotility, this allows future effectiveness studies for nonsurgical treatment and prevention of NEC.

Differential changes in TGF-β/BMP signaling pathway in the right ventricular myocardium of newborns with hypoplastic left heart syndrome

BACKGROUND

Hypoplastic left heart syndrome (HLHS) is characterized by underdevelopment of the left ventricle (LV) and increased biomechanical stress on the right ventricle (RV) from single ventricle physiology. Despite the clinical significance, the signaling pathways active during RV remodeling and disease progression are not known. To address this, we examined differential changes in expression of genes associated with transforming growth factor-beta (TGF-beta)/bone morphogenetic protein (BMP) signaling in RV tissue isolated from HLHS patients relative to RV and LV tissue from control subjects.

METHODS AND RESULTS

Quantitative real-time polymerase chain reaction was used to detect changes in expression of 84 genes involved in TGF-beta/BMP-mediated cardiac development, cell growth, and differentiation in RV tissue collected from 6 neonates with HLHS undergoing stage 1 Norwood procedure (age, 1-7 days; mean, 4 days) and RV and LV tissue obtained from 5 infants with noncardiac pathology (age range, 1-135 days: mean, 85 days) that served as controls. Analysis of gene expression profiles between control-LV and control-RV revealed significant depression of TGF-beta/BMP signaling in RV compared with LV. Of the 84 genes analyzed, 38 were differentially expressed between HLHS-RV and control-RV, whereas only 22 compared with control-LV. Significant changes were observed in: tissue remodeling genes including Activin receptor type IIA (ACVR2A) (+2.13) and Activin receptor-like kinase 1 (ACVRL1) (+2.22); and cell survival, growth, and differentiation genes including CDC25A (+2.18), p21 (-3.64), p15 (+2.15), BMP5 (+4.58), BMP3 (+2.16), GDF3 (+8.59), NODAL (+2.32), and BMP binding endothelial regulator (BMPER) (+4.58). The most significant changes common to HLHS-RV versus control-RV and control-LV sample groups is observed for Anti müllerian hormone receptor 2 (AMHR2) (+18.79 control-RV, +3.38 control-LV), and the BMP antagonist Inhibin alpha (INHA) (+11.47 control-RV, +5.73 control-LV).

CONCLUSIONS

Although this descriptive study does not allow cause-effect inferences, our results suggest changes in cardiac development pathways and upregulation of genes associated with cell growth and differentiation in the neonatal RV of children with HLHS. These molecular profiles are more closely related to those observed in the normal LV rather than normal RV at similar maturational age. This work provides the basis for future mechanistic studies to elucidate the molecular mechanisms regulating RV remodeling in HLHS.