Modeling Tissue Expansion with Isogeometric Analysis: Skin Growth and Tissue Level Changes in the Porcine Model.

BACKGROUND: Tissue expansion relies on the ability of skin to grow in response to sustained mechanical strain. This study focuses on correlation of cellular and histologic changes with skin growth and deformation during tissue expansion. METHODS: Tissue expanders were placed underneath the skin of five Yucatan minipigs and inflated with one fill of 60 cc of saline 1 hour, 24 hours, 3 days, and 7 days before the animals were killed, or two fills of either 30 cc or 60 cc at 10 and 3 days or 14 and 7 days before the animals were killed. Skin biopsy specimens and three-dimensional photographs were used to calculate skin growth and stretch according to the authors' novel finite element analysis model. RESULTS: The mitotic index of keratinocytes in the basal layer increased 1 hour after stimulus was applied (4 percent) (p = 0.022), peaked at approximately day 3 (26 percent) (p < 0.0001), and tapered by day 7 (12.5 percent) (p = 0.012) after tissue expansion. The authors demonstrated that it is the volume per fill rather than the total volume in the expander that scales the magnitude of response. Lastly, the authors demonstrated that the ratio of deformation attributable to growth versus stretch (Fgrowth/Fstretch) after 60 cc of tissue expansion fill was 1.03 at 1 hour, 0.82 at 1 day, 0.85 at day 3, and 0.95 at 7 days. CONCLUSIONS: Peak cell proliferation occurred 3 days after tissue expansion fill and is scaled in response to stimulus magnitude. The growth component of deformation equilibrates to the stretch component at day 7, as cell proliferation has started to translate to skin growth.

Prophylactic Use of Buccal Fat Flaps to Improve Oral Mucosal Healing following Furlow Palatoplasty.

Furlow palatoplasty is increasingly used both for primary palatoplasty and for secondary correction of velopharyngeal insufficiency. Although Furlow palatoplasty offers the advantage of lengthening the palate, the most tenuous component of the oral mucosal repair is anterior transposition of the oral mucosal Z-plasty flap, with superficial separation of the oral mucosa observed in up to 53 percent of cases of secondary Furlow palatoplasty. To mitigate this problem, the authors prophylactically placed pedicled buccal fat pad flaps to provide an additional vascular layer to promote healing of the overlying oral mucosal Z-plasty flap. The authors report their experience comprising seven patients who underwent Furlow palatoplasty with buccal fat flap augmentation. Four of these patients had secondary Furlow palatoplasty procedures; one of them experienced oral mucosal separation that healed uneventfully. No patients developed an oronasal fistula. The authors' experience suggests that buccal fat flaps may minimize vascular compromise and dehiscence of the oral mucosal Z-plasty following Furlow palatoplasty. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, IV.

Improving tissue expansion protocols through computational modeling.

Tissue expansion is a common technique in reconstructive surgery used to grow skin in vivo for correction of large defects. Despite its popularity, there is a lack of quantitative understanding of how stretch leads to growth of new skin. This has resulted in several arbitrary expansion protocols that rely on the surgeon's personal training and experience rather than on accurate predictive models. For example, choosing between slow or rapid expansion, or small or large inflation volumes remains controversial. Here we explore four tissue expansion protocols by systematically varying the inflation volume and the protocol duration in a porcine model. The quantitative analysis combines three-dimensional photography, isogeometric kinematics, and finite growth theory. Strikingly, all four protocols generate similar peak stretches, but different growth patterns: Smaller filling volumes of 30 ml per inflation did not result in notable expander-induced growth neither for the short nor for the long protocol; larger filling volumes of 60 ml per inflation trigger skin adaptation, with larger expander-induced growth in regions of larger stretch, and more expander-induced growth for the 14-day compared to the 10-day expansion protocol. Our results suggest that expander-induced growth is not triggered by the local stretch alone. While stretch is clearly a driver for growth, the local stretch at a given point is not enough to predict the expander-induced growth at that location. From a clinical perspective, our study suggests that longer expansion protocols are needed to ensure sufficient growth of sizable skin patches.

Parent Coping Support Interventions During Acute Pediatric Hospitalizations: A Meta-Analysis.

CONTEXT: Parents may experience psychological distress when a child is acutely hospitalized, which can negatively affect child outcomes. Interventions designed to support parents' coping have the potential to mitigate this distress. OBJECTIVE: To describe interventions designed to provide coping support to parents of hospitalized children and conduct a meta-analysis of coping support intervention outcomes (parent anxiety, depression, and stress). DATA SOURCES: We searched Pubmed, Embase, PsycINFO, Psychiatry Online, and Cumulative Index to Nursing and Allied Health Literature from 1985 to 2016 for English-language articles including the concepts "pediatric," "hospitalization," "parents," and "coping support intervention." STUDY SELECTION: Two authors reviewed titles and abstracts to identify studies meeting inclusion criteria and reviewed full text if a determination was not possible using the title and abstract. References of studies meeting inclusion criteria were reviewed to identify additional articles for inclusion. DATA EXTRACTION: Two authors abstracted data and assessed risk of bias by using a structured instrument. RESULTS: Initial searches yielded 3450 abstracts for possible inclusion. Thirty-two studies met criteria for inclusion in the systematic review and 12 studies met criteria for inclusion in the meta-analysis. The most commonly measured outcomes were parent depression, anxiety, and stress symptoms. In meta-analysis, combined intervention effects significantly reduced parent anxiety and stress but not depression. Heterogeneity among included studies was high. LIMITATIONS: Most included studies were conducted at single centers with small sample sizes. CONCLUSIONS: Coping support interventions can alleviate parents' psychological distress during children's hospitalization. More evidence is needed to determine if such interventions benefit children.

Mental Health Conditions and Symptoms in Pediatric Hospitalizations: A Single-Center Point Prevalence Study.

BACKGROUND: Children and adolescents necessitating hospitalization for physical health conditions are at high risk for mental health conditions; however, the prevalence of mental health conditions and symptoms among hospitalized children and adolescents is uncertain. The objective of this study was to determine the proportion of hospitalized children and adolescents who have diagnosed mental health disorders or undiagnosed mental health problems. METHODS: In this single-center point prevalence study of hospitalized children between the ages of 4 and 21 years, patients or their parents reported known mental health diagnoses and use of services using the Services Assessment for Children and Adolescent, and they reported patient mental health symptoms using the Pediatric Symptom Checklist, 17-item form (PSC-17). RESULTS: Of 229 eligible patients, 119 agreed to participate. Demographic characteristics of patients who enrolled were not statistically significantly different from those of patients who declined to participate. Among participants, 26% (95% confidence interval [CI], 18%-35%) reported a known mental health diagnosis. On the PSC-17, 29% (95% CI, 21%-38%) of participants had a positive screen for mental health symptoms. Of those with a positive screen, 38% (95% CI, 21%-55%) had no known mental health diagnosis, and 26% (95% CI, 12%-43%) had not received ambulatory mental health services in the 12 months before hospitalization. CONCLUSIONS: Mental health conditions and symptoms are common among patients hospitalized in a tertiary children's hospital, and many affected patients are not receiving ambulatory mental health services.