In JoVE (1)

Other Publications (17)

Articles by Chad A. Purnell in JoVE

 JoVE Bioengineering

Quantification of Strain in a Porcine Model of Skin Expansion Using Multi-View Stereo and Isogeometric Kinematics

1Mechanical Engineering, Purdue University, 2Division of Plastic Surgery, Ann and Robert H. Lurie Children's Hospital of Chicago, Northwestern University Feinberg School of Medicine, 3Mechanical Engineering, Bioengineering, Cardiothoracic Surgery, Stanford University

JoVE 55052

Other articles by Chad A. Purnell on PubMed

Retrospective Analysis of Communication with Patients Undergoing Radiological Breast Biopsy

The Journal of Supportive Oncology. Nov-Dec, 2010  |  Pubmed ID: 21265393

This study explored the perceptions of women after receiving breast biopsy results over the phone in order to determine patient preferences about the timing, setting, and provider they preferred when receiving biopsy results. Participants were recruited at a large university cancer center and surveyed by phone approximately 2 weeks after they received biopsy results. A 24-item survey was developed concerning how the biopsy results were communicated, the communication skills of the person reporting the diagnosis, and ways to improve the communication of results. The survey also asked about the relative importance of hearing the results quickly, from the most knowledgeable provider, from a primary care physician, or in person. We surveyed 59 patients (25 cancer, 34 benign). Patients from both groups were satisfied with the communication skills of the person who gave the results. However, patients with cancer and patients undergoing their first breast biopsy were more likely to need additional materials to understand their results (P = 0.018, P = 0.036, respectively). Both cancer and benign groups ranked hearing the results quickly as the most important aspect of communication and hearing the results in person as least important. This study suggests that patients value hearing cancer diagnoses quickly more than in person. Patients having their first biopsy or with a diagnosis of cancer would prefer to have additional materials to help them understand their diagnosis.

Repair of Recurrent Hernia After Biologic Mesh Failure in Abdominal Wall Reconstruction

American Journal of Surgery. Nov, 2014  |  Pubmed ID: 25118163

Biologic mesh is commonly used in abdominal wall reconstruction but may result in increased hernia recurrence. There are minimal data on repair of these recurrent hernias.

Multi-view Stereo Analysis Reveals Anisotropy of Prestrain, Deformation, and Growth in Living Skin

Biomechanics and Modeling in Mechanobiology. Oct, 2015  |  Pubmed ID: 25634600

Skin expansion delivers newly grown skin that maintains histological and mechanical features of the original tissue. Although it is the gold standard for cutaneous defect correction today, the underlying mechanisms remain poorly understood. Here we present a novel technique to quantify anisotropic prestrain, deformation, and growth in a porcine skin expansion model. Building on our recently proposed method, we combine two novel technologies, multi-view stereo and isogeometric analysis, to characterize skin kinematics: Upon explantation, a unit square retracts ex vivo to a square of average dimensions of [Formula: see text]. Upon expansion, the unit square deforms in vivo into a rectangle of average dimensions of [Formula: see text]. Deformations are larger parallel than perpendicular to the dorsal midline suggesting that skin responds anisotropically with smaller deformations along the skin tension lines. Upon expansion, the patch grows in vivo by [Formula: see text] with respect to the explanted, unexpanded state. Growth is larger parallel than perpendicular to the midline, suggesting that elevated stretch activates mechanotransduction pathways to stimulate tissue growth. The proposed method provides a powerful tool to characterize the kinematics of living skin. Our results shed light on the mechanobiology of skin and help us to better understand and optimize clinically relevant procedures in plastic and reconstructive surgery.

The Role of Smile Train and the Partner Hospital Model in Surgical Safety, Collaboration, and Quality in the Developing World

The Journal of Craniofacial Surgery. Jun, 2015  |  Pubmed ID: 26080141

The partner hospital model identifies hospitals in the developing world to educate and enable local surgeons to deliver effective cleft care. This study aimed to determine the outcomes of this model on safety, education, and quality of surgical care.

Flap Reconstruction for Esophageal Perforation Complicating Anterior Cervical Spinal Fusion: An 18-year Experience

Plastic and Reconstructive Surgery. Global Open. May, 2015  |  Pubmed ID: 26090290

Esophageal injury following anterior cervical discectomy and fusion (ACDF) poses a significant reconstructive challenge. Buttressing flap repairs have proven beneficial; however, there remains a paucity of evidence to guide optimal flap selection.

Assessing the Impact of Blood Loss in Cranial Vault Remodeling: A Risk Assessment Model Using the 2012 to 2013 Pediatric National Surgical Quality Improvement Program Data Sets

Plastic and Reconstructive Surgery. Dec, 2015  |  Pubmed ID: 26267397

Most cranial vault remodeling for craniosynostosis is associated with substantial blood loss necessitating transfusion. The transfusion of over 25 ml/kg of red blood cells has long been considered an important safety threshold and has been proposed as a potential marker of health care quality, despite a lack of evidence. The authors sought to ascertain risk factors for transfusion in cranial vault remodeling and to quantify the effect of transfusion volume on postoperative complications.

Assessment of Head Shape by Craniofacial Teams: Structuring Practice Parameters to Optimize Efficiency

The Journal of Craniofacial Surgery. Sep, 2015  |  Pubmed ID: 26267560

Since the initiation of the "Back to Sleep Campaign" by the American Academy of Pediatrics in 1992, the incidence of referrals for positional plagiocephaly has increased by 600%. Although patients with positional plagiocephaly rarely require operative intervention, they often do require treatment with cranial molding helmets or positioning changes. The increased volume of patients makes the task of separating cases of craniosynostosis from positional head shape problems more difficult. The authors sought to determine how providers are handling this increased workload of head shape abnormality patients, especially with respect to the largest practices.

Modeling Tissue Expansion with Isogeometric Analysis: Distinguishing True Skin Growth from Elastic Skin Stretch

Plastic and Reconstructive Surgery. Oct, 2015  |  Pubmed ID: 26397523

Assessing the Impact of Blood Loss in Cranial Vault Remodeling: A Risk Assessment Model Using the 2012-2013 Pediatric National Surgical Quality Improvement Program Datasets

Plastic and Reconstructive Surgery. Oct, 2015  |  Pubmed ID: 26397536

Genetics of Cleft Palate and Velopharyngeal Insufficiency

Journal of Pediatric Genetics. Mar, 2015  |  Pubmed ID: 27617110

Velopharyngeal insufficiency (VPI) can occur in the setting of an unrepaired or repaired cleft lip and palate. The rate of VPI has been documented as high as 33% in some studies with higher rates of recurrences following surgery associated with genetic syndromes such as 22q11.2 deletions. The primary cause of VPI in these groups is still identified as the anatomic abnormalities of the velum. In this review, the anatomy and physiology of the velum are discussed along with genetic mutations associated with VPI.

The Incompatibility of Living Systems: Characterizing Growth-Induced Incompatibilities in Expanded Skin

Annals of Biomedical Engineering. May, 2016  |  Pubmed ID: 26416721

Skin expansion is a common surgical technique to correct large cutaneous defects. Selecting a successful expansion protocol is solely based on the experience and personal preference of the operating surgeon. Skin expansion could be improved by predictive computational simulations. Towards this goal, we model skin expansion using the continuum framework of finite growth. This approach crucially relies on the concept of incompatible configurations. However, aside from the classical opening angle experiment, our current understanding of growth-induced incompatibilities remains rather vague. Here we visualize and characterize incompatibilities in living systems using skin expansion in a porcine model: We implanted and inflated two expanders, crescent, and spherical, and filled them to 225 cc throughout a period of 21 days. To quantify the residual strains developed during this period, we excised the expanded skin patches and subdivided them into smaller pieces. Skin growth averaged 1.17 times the original area for the spherical and 1.10 for the crescent expander, and displayed significant regional variations. When subdivided into smaller pieces, the grown skin patches retracted heterogeneously and confirmed the existence of incompatibilities. Understanding skin growth through mechanical stretch will allow surgeons to improve-and ultimately personalize-preoperative treatment planning in plastic and reconstructive surgery.

Postoperative Flank Defects, Hernias, and Bulges: A Reliable Method for Repair

Plastic and Reconstructive Surgery. Mar, 2016  |  Pubmed ID: 26910684

Although there is a high incidence of flank defects after lateral abdominal access, there is a paucity of large studies discussing this problem. Most studies express nihilism regarding their surgical management. The goal of this study was to describe the authors' conceptualization of flank defects, with a determination of the number of true hernias versus bulges, and outcomes of surgical repair in these patients.

Treatment of Foot and Ankle Neuroma Pain With Processed Nerve Allografts

Foot & Ankle International. Oct, 2016  |  Pubmed ID: 27340257

Localized nerve pain in the foot and ankle can be a chronic source of disability after trauma and has been identified as the most common complication following operative interventions in the foot and ankle. The superficial location of the injured nerves and lack of suitable tissue for nerve implantation make this pain refractory to conventional methods of neuroma management. We describe a novel strategy for management using processed nerve allografts to bridge nerve gaps created by resection of both end neuromas and neuromas-in-continuity.

Evaluating the Rule of 10s in Cleft Lip Repair: Do Data Support Dogma?

Plastic and Reconstructive Surgery. Sep, 2016  |  Pubmed ID: 27556606

Cleft lip represents one of the most common birth defects in the world. Although the timing of cleft lip repair is contingent on a number of factors, the "rule of 10s" remains a frequently quoted safety benchmark. Initially reported by Wilhelmsen and Musgrave in 1966 and modified by Millard in 1976, this rule referred to performing surgery once patients had reached cutoffs in weight, hemoglobin, and age/leukocyte count. Despite significant advances in both surgical and anesthetic technique, the oft-quoted "rule of 10s" has not been systematically investigated since its inception.

Resolution of Cosmetic Buttock Injection-induced Inflammatory Reaction and Heart Failure After Excision of Filler Material

Plastic and Reconstructive Surgery. Global Open. Oct, 2016  |  Pubmed ID: 27826475

We present a case of a 66-year-old woman who developed heart failure and severe inflammatory reaction after the illicit cosmetic injections of polymethyl-methacrylate or polyacrylamide hydrogel from a primary care provider. After medical optimization, an en bloc excision of all injectable materials and gluteus muscle was performed, which resulted in exposure of bilateral sciatic nerves. Within 10 days, the patient's heart failure resolved and inflammatory state improved. This is the first known report of heart failure due to buttock injections and subsequent improvement after surgery.

Donor-site Morbidity of Medial and Lateral Thigh-based Flaps: A Comparative Study

Plastic and Reconstructive Surgery. Global Open. Nov, 2016  |  Pubmed ID: 27975004

Free and pedicled medial and lateral thigh-based flaps are common reconstructive procedures. However, there have been no comparative studies of morbidity between medial and lateral donor sites.

Postoperative Temporal Hollowing: Is There a Surgical Approach That Prevents This Complication? A Systematic Review and Anatomic Illustration

Journal of Plastic, Reconstructive & Aesthetic Surgery : JPRAS. Mar, 2017  |  Pubmed ID: 27894915

Temporal hollowing is a common complication following surgical dissection in the temporal region. Our objectives were to: (1) review and clarify the temporal soft tissue relationships - supplemented by cadaveric dissection - to better understand surgical approach variations and elucidate potential etiologies of postoperative hollowing; (2) identify if there is any evidence to support a surgical approach that prevents hollowing through a systematic review.

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