Three-dimensional printing in medicine: a systematic review of pediatric applications.

BACKGROUND: Three-dimensional printing (3DP) addresses distinct clinical challenges in pediatric care including: congenital variants, compact anatomy, high procedural risk, and growth over time. We hypothesized that patient-specific applications of 3DP in pediatrics could be categorized into concise, discrete categories of use. METHODS: Terms related to "three-dimensional printing" and "pediatrics" were searched on PubMed, Scopus, Ovid MEDLINE, Cochrane CENTRAL, and Web of Science. Initial search yielded 2122 unique articles; 139 articles characterizing 508 patients met full inclusion criteria. RESULTS: Four categories of patient-specific 3DP applications were identified: Teaching of families and medical staff (9.3%); Developing intervention strategies (33.9%); Procedural applications, including subtypes: contour models, guides, splints, and implants (43.0%); and Material manufacturing of shaping devices or prosthetics (14.0%). Procedural comparative studies found 3DP devices to be equivalent or better than conventional methods, with less operating time and fewer complications. CONCLUSION: Patient-specific applications of Three-Dimensional Printing in Medicine can be elegantly classified into four major categories: Teaching, Developing, Procedures, and Materials, sharing the same TDPM acronym. Understanding this schema is important because it promotes further innovation and increased implementation of these devices to improve pediatric care. IMPACT: This article classifies the pediatric applications of patient-specific three-dimensional printing. This is a first comprehensive review of patient-specific three-dimensional printing in both pediatric medical and surgical disciplines, incorporating previously described classification schema to create one unifying paradigm. Understanding these applications is important since three-dimensional printing addresses challenges that are uniquely pediatric including compact anatomy, unique congenital variants, greater procedural risk, and growth over time. We identified four classifications of patient-specific use: teaching, developing, procedural, and material uses. By classifying these applications, this review promotes understanding and incorporation of this expanding technology to improve the pediatric care.

Treatment of pediatric pulmonary hypertension with simvastatin: an observational study.

BACKGROUND: Animal studies and an adult human case series suggest that statins may have a role in the treatment of pulmonary hypertension. We reviewed the results of empirical therapy for children at Primary Children's Medical Center to determine whether simvastatin had a favorable effect on non-invasive estimates of pulmonary arterial pressure. MATERIALS AND METHODS: The medical records of children with pulmonary hypertension who were treated with simvastatin were reviewed. Mean measurements of the gradient of tricuspid valve regurgitation before and after treatment were compared by a paired t-test. A favorable response to simvastatin was defined as a 20% decrease in the average measurement of the gradient of tricuspid valve regurgitation or a 20% decrease in right ventricular anterior wall thickness when tricuspid valve regurgitation resolved during treatment. Potential factors associated with a favorable response to simvastatin were identified with a Fisher exact test. RESULTS: Twelve children, 4-15 years of age, had adequate Doppler velocity waveforms to reliably measure gradients of tricuspid valve regurgitation during a period of 1 year before treatment. Eleven patients had gradients of tricuspid valve regurgitation that could be measured during a period of 1 year after treatment. Patients were treated with simvastatin 0.09-0.28 mg/kg/day. Collectively, there was no difference between the average measurements of the gradient of tricuspid valve regurgitation before and after treatment (66 ± 21 mmHg vs. 63 ± 28 mmHg). Three of the five patients with clinical findings consistent with alveolar hypoxia and none of the seven patients without clinical findings consistent with alveolar hypoxia had a favorable response to treatment with simvastatin (P = 0.05). CONCLUSION: Simvastatin may decrease pulmonary arterial pressure in a subset of patients with pulmonary hypertension.