Biofeedback therapy for children: What is the maximum number of sessions we should offer?

BACKGROUND: Biofeedback therapy is an effective but resource intensive treatment for pediatric dysfunctional voiding. Based on our center's experience, we evaluated the rate of clinical improvement from biofeedback in order to identify the maximum number of sessions to offer patients. METHODS: We reviewed 490 pediatric patients who underwent at least 6 sessions of biofeedback from 2013 to 2021. At each session, patients and their parents documented their urinary symptoms (urgency, frequency, pain, and difficulties with stream), incontinence, medications, and stool pattern. This longitudinal data was abstracted, and the log odds of urinary symptoms or incontinence was modelled with number of sessions as a predictor using generalized estimating equations and robust standard errors in SAS v9.4. Gender and bowel dysfunction were included as interactions terms. A logistic regression using absence of urinary symptoms at last biofeedback session as a dependent variable was done to further explore differences between genders. RESULTS: Patients were predominantly female (324/490, 66%) with a mean age of 8.9 years (SD 3.3 years). Most common symptoms at presentation were urinary urgency (389/490, 79%) and urinary incontinence (413/490, 84%). Medication use was common at the time of the first session (191/490, 39%) with males more likely to be on alpha-blockers (54/166 vs 1/324, p < 0.001) and females more likely to be on antibiotic prophylaxis (68/324 vs 2/166, p < 0.001). The probability of having urinary symptoms or incontinence decreased up to session 11 (9 months from initial visit). There was slower rate of improvement after session 8 (3 months). Controlling for age, symptoms, and medication use at initial visit, male patients were less likely to report symptom resolution at the time of the last session (OR 0.55, 95% CI 0.33, 0.89). The nadir for reporting symptoms occurred by session 22 for male patients, compared to session 10 for female patients. CONCLUSIONS: Clinical improvement from biofeedback for pediatric patients with dysfunctional voiding may take up to 9 months of therapy, but most cases that improve do so by 3 months. The effect of gender on biofeedback efficacy requires further study, but males may have slower response to biofeedback. Our data provides guidance on when maximum benefit from biofeedback can be expected before considering re-evaluation or other therapies for lower urinary tract symptoms.

Mandibular advancement reduces pharyngeal collapsibility by enlarging the airway rather than affecting velopharyngeal compliance.

Mandibular advancement devices (MADs) are frequently prescribed for obstructive sleep apnea (OSA) patients, but approximately one third of patients experience no therapeutic benefit. Understanding the mechanisms by which MADs prevent pharyngeal collapse may help optimize MAD therapy. This study quantified the relative contributions of changes in airspace cross-sectional area (CSA) versus changes in velopharyngeal compliance in determining MAD efficacy. Sixteen patients with moderate to severe OSA (mean apnea-hypopnea index of 32 ± 15 events/h) underwent measurements of the velopharyngeal closing pressure (PCLOSE ) during drug induced sedated endoscopy (DISE) via stepwise reductions in nasal mask pressure and recording of the intraluminal pressure with a catheter. Airspace CSA was estimated from video endoscopy. Pharyngeal compliance was defined as the slope of the area-pressure relationship of the velopharyngeal airspace. MAD therapy reduced PCLOSE from a median of 0.5 cmH2 O pre-advancement to a median of -2.6 cmH2 O post-advancement (p = 0.0009), increased the minimal CSA at the velopharynx by approximately 20 mm2 (p = 0.0067), but did not have a statistically significant effect on velopharyngeal compliance (p = 0.23). PCLOSE had a strong correlation with CSA but did not correlate with velopharyngeal compliance. Our results suggest that MADs reduce velopharyngeal collapsibility by increasing airway size as opposed to affecting velopharyngeal compliance. This contradicts the speculation of previous literature that the effectiveness of MADs is partially due to a reduction in velopharyngeal compliance resulting from stretching of the soft palate. These findings suggest that quantification of velopharyngeal CSA pre- and post-MAD advancement has potential as a biomarker to predict the success of MAD therapy.

Modeling early thermal injury using an ex vivo human skin model of contact burns.

BACKGROUND: Early mechanisms underlying the progressive tissue death and the regenerative capability of burn wounds are understudied in human skin. A clinically relevant, reproducible model for human burn wound healing is needed to elucidate the early changes in the human burn wound environment. This study reports a reproducible contact burn model on human skin that explores the extent of tissue injury and healing over time, and defines the inter-individual variability in human skin to enable use in mechanistic studies on burn wound progression and healing. METHODS: Using a customized burn device, contact burns of various depths were created on human skin by two operators and were evaluated for histologic depth by three raters to determine reproducibility. Early burn wound progression and wound healing were also evaluated histologically after the thermally injured human skin was cultured ex vivo for up to 14 days. RESULTS: Burn depths were reproducibly generated on human skin in a temperature- or time-dependent manner. No significant difference in operator-created or rater-determined depth was observed within each patient sample. However, significant inter-individual variation was identified in burn depth in ten patient samples. Burn-injured ex vivo human skin placed into culture demonstrated differential progression of cell death and collagen denaturation for high and low temperature contact burns, while re-epithelialization was observed in superficial burn wounds over a period of 14 days. CONCLUSION: This model represents an invaluable tool to evaluate the inter-individual variability in early burn wound progression and wound healing to complement current animal models and enhance the translation of preclinical research to improvements in patient care.