Jeffrey Lisiecki

Demystifying the U.S. food and drug administration: Understanding regulatory pathways

Background: The field of plastic surgery has been at the forefront of ideation and innovation. Surgeon scientists today continue to develop novel products that fulfill the needs of the medical community and patients. Part of this process requires the approval from various regulatory agencies and offices, including the U.S. Food and Drug Administration. Unfortunately, medical training does not include regulatory knowledge, and many surgeon scientists find the regulatory pathway and U.S. Food and Drug Administration perplexing, overly complicated, and insurmountable. The authors aim to clearly outline the path of the regulatory process as it pertains to the U.S. Food and Drug Administration and its various jurisdictions that may relate to the plastic surgeon. Methods: The authors aim to demystify the classification system, 510(k), and Premarket Approval processes for devices; clarify the Investigational New Drug and New Drug Application requirements for drugs; and explain how human cells, tissues, and cellular or tissue-based products are classified and approvals obtained. Results: The structure of the U.S. Food and Drug Administration, its offices, and their roles are delineated, and the complex process of obtaining approval to market devices, drugs, biologics, and combination products is explained in a manner that is broadly useful to innovators whether new or experienced. Conclusion: The authors provide information for innovators and inventors developing promising technologies to be more knowledgeable and motivated to embrace the process in a fashion that will potentially save time and errors in U.S. Food and Drug Administration submissions.

Pierre Robin sequence and Treacher Collins hypoplastic mandible comparison using three-dimensional morphometric analysis.

AbstractPierre Robin sequence and Treacher Collins syndrome are both associated with mandibular hypoplasia. It has been hypothesized, however, that the mandible may be differentially affected. The purpose of this study was to therefore compare mandibular morphology in children with Pierre Robin sequence with children with Treacher Collins syndrome using three-dimensional analysis of computed tomographic scans. A retrospective analysis was performed identifying children with Pierre Robin sequence and Treacher Collins syndrome undergoing computed tomography. Three-dimensional reconstruction was performed, and ramus height, mandibular body length, and gonial angle were measured. These were then compared with those in control children with normal mandibles and with the clinical norms corrected for age and sex based on previously published measurements. Mandibular body length was found to be significantly shorter for children with Pierre Robin sequence, whereas ramus height was significantly shorter for children with Treacher Collins syndrome. This resulted in distinctly different ramus height–mandibular body length ratios. In addition, the gonial angle was more obtuse in both the Pierre Robin sequence and Treacher Collins syndrome groups compared with the controls. Three-dimensional mandibular morphometric analysis in patients with Pierre Robin sequence and Treacher Collins syndrome thus revealed distinctly different patterns of mandibular hypoplasiarelative to normal controls. These findings underscore distinct considerations that must be made in surgical planning for reconstruction.

Use of morphometric assessment of body composition to quantify risk of surgical-site infection in patients undergoing component separation ventral hernia repair.

Background: Body mass index does not allow accurate risk stratification for individuals undergoing component separation repair of ventral hernias. The authors hypothesized that tissue morphology measurements (morphomics) of preoperative computed tomography scans stratify the risk of surgical site infection in patients undergoing ventral hernia repair with a component separation technique. Methods: The authors identified 93 patients who underwent component release ventral hernia repair (2004 to 2012). The surgical technique involved release of the external oblique muscle lateral to the linea semilunaris. Using analytic morphomic techniques, the authors measured patients’ morphology using routine preoperative computed tomography scans. Two-sample t test was used to evaluate the effect of morphomic and demographic factors on surgical-site infection. Separate logistic regression analyses were performed on these morphomic factors to evaluate their predictive value in assessing the risk of surgical site infection, controlling for demographic covariates. Results: Surgical site infections were observed in 31 percent (n = 29) of the population. Subcutaneous fat area, total body area, and total body circumference had increased odds ratios for surgical site infection (p = 0.004, 0.014, and 0.012, respectively), indicating that these measures are better associated with surgical site infection than body mass index. These calculations control for demographic covariates, confirming that these morphomic parameters are predictive of surgical site infection. Conclusion: Specific morphomic values serve as superior predictors of surgical site infection in patients undergoing component separation technique hernia repair than currently used values such as body mass index. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Role of Anatomical Region and Hypoxia on Angiogenic Markers in Adipose-Derived Stromal Cells

BACKGROUND Recent research into adipose-derived stem cells (ASCs) suggests that anatomical location has a major impact on the metabolic profile and differentiation capacity of ASCs. By having a better understanding of how various ASCs respond to cellular stressors such as hypoxia, which are induced during routine surgical procedures, we can facilitate future development of cell-based therapies to improve wound healing. PATIENTS AND METHODS Human ASCs were isolated from the superficial and deep adipose layers of four patients undergoing elective abdominoplasty. ASCs were cultured in hypoxic (1% O2, 5% CO2, and 94% N2) conditions. After 12 and 48 hours, ASCs were assessed for markers of angiogenesis by mRNA levels of vascular endothelial growth factor A (VEGF-A), vascular endothelial growth factor B (VEGF-B), and hypoxia inducible factor 1 α (HIF-1α). Western blot analysis was performed to assess levels of VEGF-A, p-NF-κB, and NF-κB. In addition, in vitro analysis of angiogenesis was performed using Matrigel assay (BD Biosciences, Franklin Lakes, NJ). RESULTS We observed significant increases in deep ASCs VEGF-A, VEGF-B, and HIF-1α mRNA expression compared with the superficial layer after 24-hour hypoxia (p < 0.05). Similar results were found when examining protein expression levels, with the deep ASCs expressing significantly larger amounts of VEGF-A and p-NF-κB (p < 0.05) compared with the superficial layer. CONCLUSION Our results suggest that significant variations exist in the angiogenic profile of superficial and deep ASCs. We demonstrate that superficial ASCs are less prone to transcribe potent chemokines for angiogenesis, such as VEGF-A, VEGF-B, and HIF-1α and are less likely to translate VEGF-A and NF-κB. This may help with the selection of specific stem cell donor sites in future models for stem cell therapy.

Novel application of human morphomics to quantify temporal soft tissues in Pierre Robin and Treacher Collins.

Introduction Pierre Robin sequence (PR) and Treacher Collins syndrome (TC) are congenital disorders associated with multiple craniofacial abnormalities. The mandibular malformations linked with these maladies are closely associated with the form and function of the temporalis muscle. Despite these associations, a paucity of research has been directed at quantifying how these malformations affect the tissues of the temporal region. In this paper, we seek to quantify differences in the temporalis muscle and the temporal fat pad using a novel CT-derived analytic program to examine craniofacial morphomic indices within these patient groups in comparison to normal age-matched controls. We posit that the temporalis muscle and temporal fat pad, like other derivatives of the first branchial arch, are hypoplastic in patients with TC and PR compared to age-matched controls. Methods High-throughput image analysis was used to reconstruct the 3-dimensional (3D) anatomy and quantify morphomic measures of the temporalis muscle and temporal fat pad in children with PR, TC, and age-matched controls. These steps were completed in a semi-automated method using algorithms programmed in MATLAB v13.0. The 3D reconstructions were analyzed in 3 children with PR (6 temporal regions), 3 children with TC (6 temporal regions), and a control group of 19 children (38 temporal regions). We also quantified the same measurements in a localized “core” sample in the area of greatest thickness, providing a more consistent sample of the tissue position. Relationships between the temporal muscle and fat pad values and craniofacial abnormality type were assessed using Wilcoxon nonparametric test using exact distribution, with a P value of less than 0.05 being deemed significant. Results The mean age of our patients was 6.0 years in PR and 4.5 years in TC cohorts. We were able to establish an automated methodology to quantify the temporalis muscle and temporal fat pad based on CT characteristics. Localized temporalis volume and localized temporalis area were significantly smaller in children with PR than in the control group. Total temporalis fat volume and localized temporalis area were significantly less in children with TC than in the control group. When compared to each other, the PR group had small morphomic values compared to TC group. Conclusions There are significant morphomic differences in the temporalis muscle and the temporal fat pad in children with either PR or TC when compared to age-matched control group which can be measured from pre-existing CT scans. Specifically, both of these test groups show decreases in the morphomic measures of the temporalis region. The quantification of these changes corroborates and objectifies the clinical findings associated with these congenital deformities while simultaneously allowing for preoperative planning. Furthermore, this finding confirms that the hypoplasia seen in these patient populations is not only hypoplasia of the mandible but also of the surrounding functional matrix, which includes the temporalis muscle and temporal fat pad.

Demystifying the U.S. Food and Drug Administration: I. Understanding agency structure and function.

The U.S. Food and Drug Administration is the government agency responsible for oversight of the safety and efficacy of pharmaceuticals and devices, including biologics and devices that combine biologics with other materials. Within the U.S. Food and Drug Administration, the Center for Biologics Evaluation and Research is specifically responsible for the evaluation and approval of biological products. This department of the U.S. Food and Drug Administration has a series of mechanisms in place to aid researchers in the process of developing new biologics. This article outlines the study phases involved in developing new biologics and how the Center for Biologics Evaluation and Research and investigators can work together to facilitate this process. It also discusses issues specific to biologics that have been encountered in the past and that investigators should consider when developing and obtaining approval for new biologics. The equivalent center within the U.S. Food and Drug Administration for approving medical devices is the Center for Devices and Radiological Health. The equivalent process of development and approval of medical devices is similarly discussed. Finally, essential contacts for investigators within the Center for Biologics Evaluation and Research and the Center for Devices and Radiological Health are provided.

Adipose-derived mesenchymal stem cells from ventral hernia repair patients demonstrate decreased vasculogenesis.

Introduction. In adipose tissue healing, angiogenesis is stimulated by adipose-derived stromal stem cells (ASCs). Ventral hernia repair (VHR) patients are at high risk for wound infections. We hypothesize that ASCs from VHR patients are less vasculogenic than ASCs from healthy controls. Methods. ASCs were harvested from the subcutaneous fat of patients undergoing VHR by the component separation technique and from matched abdominoplasty patients. RNA and protein were harvested on culture days 0 and 3. Both groups of ASCs were subjected to hypoxic conditions for 12 and 24 hours. RNA was analyzed using qRT-PCR, and protein was used for western blotting. ASCs were also grown in Matrigel under hypoxic conditions and assayed for tubule formation after 24 hours. Results. Hernia patient ASCs demonstrated decreased levels of VEGF-A protein and vasculogenic RNA at 3 days of growth in differentiation media. There were also decreases in VEGF-A protein and vasculogenic RNA after growth in hypoxic conditions compared to control ASCs. After 24 hours in hypoxia, VHR ASCs formed fewer tubules in Matrigel than in control patient ASCs. Conclusion. ASCs derived from VHR patients appear to express fewer vasculogenic markers and form fewer tubules in Matrigel than ASCs from abdominoplasty patients, suggesting decreased vasculogenic activity.

Temporal morphomics as a model for determining preoperative risk of blood transfusion in nonsyndromic craniosynostosis patients.

Background: Estimates of blood loss during craniosynostosis surgeries have ranged from 42 to 126 percent of infant’s total blood volume. Currently, no risk model has been developed to determine the likelihood of needing a blood transfusion. The authors propose an objective model, based on patients’ three-dimensional anatomical characteristics, to stratify the likelihood of needing perioperative packed red blood cells. Methods: High-throughput image analysis from already ordered preoperative computed tomographic scans was used to reconstruct the three-dimensional anatomy of the temporalis muscle and overlying temporal fat pad. Using these morphomic measurements, the authors created a risk assessment model of the amount of packed red blood cells infused based on morphomic variations in temporal soft tissue. Results: The authors evaluated 139 infants with nonsyndromic craniosynostosis from the University of Michigan Health System. Results show the need for blood transfusion ranged from 94.1 percent among patients in the smallest quartile for temporal fat pad volume compared with 65.7 percent among the group with the largest quartile for temporal fat pad volume (p = 0.0057). Using multivariable linear regression, temporal fat pad volume (p = 0.012) and fat pad thickness (p = 0.036) were independent predictors for amount of packed red blood cells required. Conclusions: The authors demonstrate that patients with diminished temporal fat pad volume are significantly more likely to need increased packed red blood cell transfusions. In addition, by use of multivariable linear regression, their data suggest that temporal fat pad volume and thickness were independent predictors for the amount of required transfusion of packed red blood cells. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Morphomic measurement of the temporalis muscle and zygomatic bone as novel predictors of hospital-based clinical outcomes in patients with mandible fracture

Introduction Patients with mandibular fracture often have comorbidities and concomitant injuries making the decision for when and how to operate a challenge. Physicians describe “temporalis wasting” as a finding that indicates frailty; however, this is a subjective finding without quantitative values. In this study, we demonstrate that decreased morphomic values of the temporalis muscle and zygomatic bone are an objective measure of frailty associated with increased injury-induced morbidity as well as negative impact on overall hospital-based clinical outcomes in patients with mandible fracture. Methods Computed tomographic (CT) scans from all patients with a diagnosis of a mandible fracture in the University of Michigan trauma registry and with a hospital admission were collected from the years 2004 to 2011. Automated, high-throughput CT analysis was used to reconstruct the anatomy and quantify morphomic values (temporalis volume, area and thickness, and zygomatic thickness) in these patients using MATLAB v13.0 (MathWorks Inc, Natick, MA, USA). Subsequently, a subset of 16 individuals with a Glasgow Coma Scale of 14 or 15 was analyzed to control for brain injury. Clinical data were obtained, and the association between morphomic measurements and clinical outcomes was evaluated using Pearson correlation for unadjusted analysis and multiple regression for adjusted analysis. Results The mean age of patients in the study was 47.1 years. Unadjusted analysis using Pearson correlation revealed that decreases in zygomatic bone thickness correlated strongly with increases in hospital, intensive care unit, and ventilator days (P < 0.0001, P = 0.0003, and P = 0.0017, respectively). Furthermore, we found that decreases in temporalis mean thickness correlated with increases in hospital and ventilator days (P = 0.0264 and P = 0.0306, respectively). Similarly, decreases in temporalis local mean thickness are significantly correlated with increases in hospital and ventilator days (P = 0.0232 and P = 0.0472, respectively). Conclusions Decreased thicknesses of the zygomatic bone and temporalis muscle are significantly correlated with higher hospital, ventilator, and intensive care unit days in patients with mandibular fracture receiving reconstructive operations. This morphomic methodology provides an accurate, quantitative means to evaluate craniofacial trauma patient frailty, injury, and outcomes using routinely obtained CT scans. In the future, we plan to apply this approach to determine preoperative risk stratification and assist in surgical planning.

Abstract 114: use of morphomic analysis for preoperative risk stratification in patients undergoing major head and neck cancer surgery.

introduCtion: Post-operative complications following major head and neck cancer surgery (MHNCS) are associated with significant morbidity and mortality. The ability to stratify pre-operative risk based on already available objective measures could improve pre-operative counseling and decision making. Currently, pre-operative risk is assessed based on comorbidities. Traditionally, patient assessment has been performed using comorbidities. However, an emerging field of patient assessment involves the evaluation anatomic morphology to measure patient frailty. We hypothesize that the morphologic characteristics of the temporalis region in patients undergoing MHNCS can serve as a reliable marker for risk of complications.