Rodney K Chan

U.S. Army Institute of Surgical Research, Houston, Texas, United States

Are you Rodney K Chan?

Claim your profile

Publications (54)133.86 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The use of autograft skin is essential in the treatment of full thickness burns and large cutaneous defects. Both autograft thickness and condition of the wound bed modulate aesthetic and functional outcomes. Thicker autografts contract less and maintain greater functionality as the scar matures. The presence of hypodermis can also positively affect the eventual appearance and functionality of the wound site by modulating contraction and alleviating inflammation and cellular stress responses. In this study we characterize wound-site physical and cellular characteristics following split-thickness skin grafting onto hypodermis vs. onto fascia. Compared to autografts grafted onto fascia, identical thickness autografts grafted onto fat demonstrated reduced contraction, enhanced mobility and vascularity, and reduced topographical variability. Grafts onto fat also showed reduced levels of myofibroblasts and leukocytic infiltration. The status of the wound bed prior to engraftment is an important contributor of skin quality outcome. The presence of hypodermis is associated with improved functional and aesthetic qualities of split thickness skin grafts, which are correlated with reduced presence of myofibroblasts and leukocytic infiltration. This article is protected by copyright. All rights reserved. © 2015 by the Wound Healing Society.
    Wound Repair and Regeneration 02/2015; DOI:10.1111/wrr.12267 · 2.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: The contemporary treatment of a full-thickness burn consists of early eschar excision followed by immediate closure of the open wound using autologous skin. However, most animal models study burn wound healing with the persistence of the burn eschar. Our goal is to characterize a murine model of burn eschar excision to study wound closure kinetics. Approach: C57BL/6 male mice were divided into three groups: contact burn, scald burn, or unburned control. Mice were burned at 80°C for 5, 10, or 20 s. After 2 days, the eschar was excised and wound closure was documented until postexcision day 13. Biopsies were examined for structural morphology and α-smooth muscle actin. In a subsequent interval-excision experiment (80°C scald for 10 s), the burn eschar was excised after 5 or 10 days postburn to determine the effect of a prolonged inflammatory focus. Results: Histology of both contact and scald burns revealed characteristics of a full-thickness injury marked by collagen coagulation and tissue necrosis. Excision at 2 days after a 20-s burn from either scald or contact showed significant delay in wound closure. Interval excision of the eschar, 5 or 10 days postburn, also showed significant delay in wound closure. Both interval-excision groups showed prolonged inflammation and increased myofibroblasts. Innovation and Conclusions: We have described the kinetics of wound closure in a murine model of a full-thickness burn excision. Both contact and scald full-thickness burn resulted in significantly delayed wound closure. In addition, prolonged interval-excision of the eschar appeared to increase and prolong inflammation.
    02/2015; 4(2):83-91. DOI:10.1089/wound.2014.0570
  • [Show abstract] [Hide abstract]
    ABSTRACT: Burns constitute approximately 10% of all combat-related injuries to the head and neck region. We postulated that the combat environment presents unique challenges not commonly encountered among civilian injuries. The purpose of the present study was to determine the features commonly seen among combat facial burns that will result in therapeutic challenges and might contribute to undesired outcomes. The present study was a retrospective study performed using a query of the Burn Registry at the US Army Institute of Surgical Research Burn Center for all active duty facial burn admissions from October 2001 to February 2011. The demographic data, total body surface area of the burn, facial region body surface area involvement, and dates of injury, first operation, and first facial operation were tabulated and compared. A subset analysis of severe facial burns, defined by a greater than 7% facial region body surface area, was performed with a thorough medical record review to determine the presence of associated injuries. Of all the military burn injuries, 67.1% (n = 558) involved the face. Of these, 81.3% (n = 454) were combat related. The combat facial burns had a mean total body surface area of 21.4% and a mean facial region body surface area of 3.2%. The interval from the date of the injury to the first operative encounter was 6.6 ± 0.8 days and was 19.8 ± 2.0 days to the first facial operation. A subset analysis of the severe facial burns revealed that the first facial operation and the definitive coverage operation was performed at 13.45 ± 2.6 days and 31.9 ± 4.1 days after the injury, respectively. The mortality rate for this subset of patients was 32% (n = 10), with a high rate of associated inhalational injuries (61%, n = 19), limb amputations (29%, n = 9), and facial allograft usage (48%, n = 15) and a mean facial autograft thickness of 10.5/1,000th in. Combat-related facial burns present multiple challenges, which can contribute to suboptimal long-term outcomes. These challenges include prolonged transport to the burn center, delayed initial intervention and definitive coverage, and a lack of available high-quality color-matched donor skin. These gaps all highlight the need for novel anti-inflammatory and skin replacement strategies to more adequately address these unique combat-related obstacles. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. All rights reserved.
    Journal of Oral and Maxillofacial Surgery 01/2015; 73(1):106-11. DOI:10.1016/j.joms.2014.08.022 · 1.28 Impact Factor
  • Journal of burn care & research: official publication of the American Burn Association 11/2014; DOI:10.1097/BCR.0000000000000219 · 1.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Oxygen plays an important role in wound healing, as it is essential to biological functions such as cell proliferation, immune responses and collagen synthesis. Poor oxygenation is directly associated with the development of chronic ischemic wounds, which affect more than 6 million people each year in the United States alone at an estimated cost of $25 billion. Knowledge of oxygenation status is also important in the management of burns and skin grafts, as well as in a wide range of skin conditions. Despite the importance of the clinical determination of tissue oxygenation, there is a lack of rapid, user-friendly and quantitative diagnostic tools that allow for non-disruptive, continuous monitoring of oxygen content across large areas of skin and wounds to guide care and therapeutic decisions. In this work, we describe a sensitive, colorimetric, oxygen-sensing paint-on bandage for two-dimensional mapping of tissue oxygenation in skin, burns, and skin grafts. By embedding both an oxygen-sensing porphyrin-dendrimer phosphor and a reference dye in a liquid bandage matrix, we have created a liquid bandage that can be painted onto the skin surface and dries into a thin film that adheres tightly to the skin or wound topology. When captured by a camera-based imaging device, the oxygen-dependent phosphorescence emission of the bandage can be used to quantify and map both the pO2 and oxygen consumption of the underlying tissue. In this proof-of-principle study, we first demonstrate our system on a rat ischemic limb model to show its capabilities in sensing tissue ischemia. It is then tested on both ex vivo and in vivo porcine burn models to monitor the progression of burn injuries. Lastly, the bandage is applied to an in vivo porcine graft model for monitoring the integration of full- and partial-thickness skin grafts.
    Biomedical Optics Express 11/2014; 5(11). DOI:10.1364/BOE.5.003748 · 3.50 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The goal of burn surgical therapy is to minimize mortality and to return survivors to their preinjury state. Prompt removal of the burn eschar, early durable coverage, and late corrections of functional deformities are the basic surgical principles. The operative burden, while presumed to be substantial and significant, is neither well described nor quantified. The burn registry at the U.S. Institute of Surgical Research Burn Center was queried from March 2003 to August 2011 for all active duty burn admissions; active duty subjects were chosen to eliminate subject follow-up as a significant variable. Subject demographics including age, sex, branch of service, injury type, injury severity score, transfusion, allograft use, length of stay, mechanism of injury, and survival were tabulated as were their percentage TBSA, specific body region involvement, and nature and dates of operations performed. Univariate analysis and multiple logistic regressions were performed to determine independent factors which predict early and late operative burden. In the 8-year study period, 864 active duty patients were admitted to the burn center. Among them, 569 (66%) were operative in nature. The operations that were performed during acute hospitalization were 62%, while the remaining 38% were performed following discharge. A linear relationship exists between TBSA and the number of acute operations with an average of one acute operation required per 5% TBSA. No direct relationships however were found between TBSA and the number of reconstructive operations. Based on multiple logistic regression, battle vs nonbattle (OR, 0.559; 95% confidence interval [CI], 0.298-1.050; P = .0706), injury severity score (OR, 1.021; 95% CI, 1.003-1.039; P = .0222), intensive care unit length of stay (OR, 1.076; 95% CI, 1.053-1.099; P ≤ .0001), allograft use (OR, 2.610; 95% CI, 1.472-4.628; P = .0010), and TBSA of the trunk (OR, 0.982; 95% CI, 0.965-1.000; P = .0439) (but not overall TBSA) were associated with a high acute operative burden. Battle vs nonbattle (OR, 0.546; 95% CI, 0.360-0.829; P = .0045), and TBSA of the upper extremities (OR, 1.008; 95% CI, 1.002-1.013; P = .0042) were noted to be significant variables in predicting late reconstruction operations. The operative burden of burn, not previously well characterized, consists of operations performed during as well as after the initial hospitalization. While injury severity and truncal involvement are significant determinants of acute surgical therapy, the presence of upper extremity burns is a significant determinant of reconstruction following discharge.
    Journal of burn care & research: official publication of the American Burn Association 08/2014; DOI:10.1097/BCR.0000000000000132 · 1.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Bone regeneration and healing is an area of extensive research providing an ever-expanding set of not only therapeutic solutions for surgeons but also diagnostic tools. Multiple factors such as an ideal graft, the appropriate biochemical and mechanical wound environment, and viable cell populations are essential components in promoting healing. While bony tissue performs many functions, critical is mechanical strength, followed closely by structure. Many tools are available to evaluate bone quality in terms of quantity, structure, and strength; the purpose of this article is to identify the factors that can be evaluated and the advantages and disadvantages of each in assessing the quality of bone healing in both preclinical research and clinical settings.
    Wound Repair and Regeneration 05/2014; 22(S1). DOI:10.1111/wrr.12167 · 2.77 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: INTRODUCTION: Non-battle injuries (NBIs) can be a source of significant resource utilization for the armed forces in a deployed setting. While the incidence and severity of craniomaxillofacial (CMF) battle injuries (BIs) have reportedly increased in the ongoing U.S. military conflicts in Iraq and Afghanistan, the prevalence and the nature of NBIs are not well described. MATERIAL AND METHODS: The Joint Theater Trauma Registry was queried from October 2001 to February 2011, covering Operations Enduring Freedom and Iraqi Freedom, for both NBIs and BIs to the CMF region. Patient demographics, injury severity score, mechanism and type of injury were included in the query. Using ICD-9 diagnosis codes, CMF injuries were classified according to type (wounds, fractures, burns, vascular injuries, and nerve injuries). Statistical analysis was performed for comparative analysis. RESULTS: NBIs constituted 24.3% of all patients with CMF injuries evacuated to a regional combat support hospital (CMF BIs 75.4%). These injuries were characterized by blunt trauma, most commonly motor vehicle collisions (37%), and falls (20%). As compared to CMF BIs, CMF NBIs resulted in less mortality (1.3% vs. 3.1%, p < 0.0001), fewer injuries per patient (1.87 vs. 2.26, p = 0.055), and a decreased severity score (ISS) (8.38 vs. 12.98, p < 0.0001). However, a significant percentage of CMF NBIs still required evacuation out of theater (27.8% of NBIs vs. 42.2% of BIs, p < 0.0001), depleting the combat strength of the deployed forces. CONCLUSIONS: CMF NBIs accounted for a substantial portion of total CMF injuries. Though characterized predominantly by blunt trauma with an overall better prognosis, its burden to the limited resources of a deployment can be significant. This descriptive study highlights the need to allocate appropriate resources for treatment of these injuries as well as strategies to reduce both its incidence and severity. LEVEL OF EVIDENCE: IV Prognostic.
    Journal of cranio-maxillo-facial surgery: official publication of the European Association for Cranio-Maxillo-Facial Surgery 04/2013; DOI:10.1016/j.jcms.2013.01.035 · 1.25 Impact Factor
  • Atlas of the oral and maxillofacial surgery clinics of North America 03/2013; 21(1):61-8. DOI:10.1016/j.cxom.2012.12.003
  • [Show abstract] [Hide abstract]
    ABSTRACT: PURPOSE: The mandible is the most commonly fractured bone in the craniomaxillofacial skeleton among military casualties. The purpose of this study was to characterize the nature and severity of mandibular fractures incurred by US military personnel during combat. MATERIALS AND METHODS: We queried the Joint Theater Trauma Registry from October 2001 to April 2011 using all pertinent International Classification of Diseases, Ninth Revision codes to identify fractures of the mandible. Fractures were then classified based on type and location. Chart reviews were performed on the subset of patients who were treated at San Antonio Military Medical Center to further classify the anatomic pattern and treatment of these fractures. RESULTS: We identified 391 patients with mandibular fractures, of whom 45 were transferred to San Antonio Military Medical Center. Open fractures were seen in 75% of patients. Two or more fractures of the mandible were seen in 51% of patients. Comminuted fractures were present in 84%, and 31% had segmental losses. Eighty-six percent of fractures were operative; two-thirds of patients required a single surgical procedure, whereas the remaining one-third required multiple procedures. Forty-six percent of patients had pan-facial fractures. CONCLUSIONS: Mandibular fractures as a result of combat blast injuries were characterized by a high incidence of open, comminuted, multiple fractures. Associated facial fractures were common.
    Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 01/2013; DOI:10.1016/j.joms.2012.10.030 · 1.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study provides objective data on the practice of allograft usage in severely burned patients. Furthermore, gaps in our knowledge are identified, and areas for further research are delineated. Using an institutional review board-approved protocol, active duty military patients injured while deployed in support of overseas contingency operations and treated at our burn center between March 2003 and December 2010 were identified. Their electronic medical records were reviewed for allograft use, TBSA burned, injury severity score, anatomic distribution of burns, operative burden, length of stay, transfusions, and outcome. Among 844 patients, 112 (13.3%) received allograft and 732 (86.7%) did not. The amount of allograft used per patient varied and was not normally distributed (median, 23.5; interquartile range, 69.5). Patients received allograft skin an average of 12.75 times during their admission. Allografted patients sustained severe burns (¼, 53.8% TBSA); most were transfused (71.2%) and grafted frequently, averaging every 7.45 days. Most commonly, allograft was placed on the extremities (66.5%) followed by the trunk (44.2%); however, the vast majority of allografted patients also had concomitant burns of the head (91.1%) and hands (87.5%). All-cause mortality among the allografted patients was 19.1%. In conclusion, allograft is commonly used in the surgical treatment of severe burns. Although there are no anatomic limitations to allograft placement, there are distinct patterns of use. Given the role of allograft in the acute management of large burns, there is need for further investigation of its effect on mortality, morbidity, and antigenicity.
    Journal of burn care & research: official publication of the American Burn Association 01/2013; 34(1):168-75. DOI:10.1097/BCR.0b013e318270000f · 1.55 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Improved armor and battlefield medicine have led to better survival in the wars in Iraq and Afghanistan than any previous ones. Increased frequency and severity of craniomaxillofacial injuries have been proposed. A comprehensive characterization of the injury pattern sustained during this 10-year period to the craniomaxillofacial region is needed to improve our understanding of these unique injuries, to optimize the treatment for these patients, and to potentially direct strategic development of protective equipment in the future. The Joint Theater Trauma Registry was queried from October 19, 2001, to March 27, 2011, covering operations Enduring Freedom and Iraqi Freedom for battle injuries to the craniomaxillofacial region, including patient demographics and mechanism of injury. Injuries were classified according to type (wounds, fractures, burns, vascular injuries, and nerve injuries) using DRG International Classification of Diseases-9th Rev. diagnosis codes. In this 10-year period, craniomaxillofacial battle injuries to the head and neck were found in 42.2% of patients evacuated out of theater. There is a high preponderance of multiple wounds and open fractures in this region. The primary mechanism of injury involved explosive devices, followed by ballistic trauma. Modern combat, characterized by blast injuries, results in higher than previously reported incidence of injury to the craniomaxillofacial region. Epidemiologic study, level IV.
    12/2012; 73(6 Suppl 5):S453-8. DOI:10.1097/TA.0b013e3182754868
  • Source
    12/2012; 73(6 Suppl 5):S409-16. DOI:10.1097/TA.0b013e318275499f
  • [Show abstract] [Hide abstract]
    ABSTRACT: Facial injuries sustained by US military personnel during the wars in Iraq and Afghanistan have increased compared with past conflicts. Characterization of midface fractures (orbits, maxilla, zygoma, and nasal bones) sustained on the battlefield is needed to improve our understanding of these injuries, to optimize treatment, and to potentially direct strategic development of protective equipment in the future. The military's Joint Theater Trauma Registry was queried for midface fractures from 2001 to 2011 using International Classification of Diseases, Ninth Revision diagnosis codes. Stratification was then performed, and individual treatment records from Brooke Army Medical Center were reviewed. Analysis of the fracture pattern, treatment, and complications was performed. One thousand seven hundred sixty individuals with midface fractures were identified. Those fractures sustained in battle were characterized by a predominance of open fractures, blast etiology, and associated injuries. Detailed record reviews of the patients treated at our institution revealed 45% of all midface fractures as operative. Thirty-one percent of these were treated at levels III and IV facilities outside the continental United States before arrival at our institution. Patients with midface fractures underwent multiple operations. There was a 30% rate of complication among operative fractures characterized by malalignment, implant exposure, and infection. Midface battle injuries also had a high incidence of orbital fractures and severe globe injuries. Midface fractures sustained in the battlefield have a high complication rate, likely as a result of the blast mechanism of injury with associated open fractures, multiple fractures, and associated injuries. These cases present unique challenges, often requiring both soft tissue and skeletal reconstruction.
    The Journal of craniofacial surgery 11/2012; 23(6):1587-91. DOI:10.1097/SCS.0b013e318256514a · 0.68 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Large body surface area burns pose significant therapeutic challenges. Clinically, the extent and depth of burn injury may mandate the use of allograft for temporary wound coverage while autografts are serially harvested from the same donor areas. The paucity of donor sites in patients with burns involving large surface areas highlights the need for better skin substitutes that can achieve early and complete coverage and retain normal skin durability with minimal donor requirements. We have isolated autologous stem cells from the adipose layer of surgically debrided burned skin (dsASCs), using a point-of-care stem cell isolation device. These cells, in a collagen-polyethylene glycol fibrin-based bilayer hydrogel, differentiate into an epithelial layer, a vascularized dermal layer, and a hypodermal layer. All-trans-retinoic acid and fenofibrate were used to differentiate dsASCs into epithelial-like cells. Immunocytochemical analysis showed a matrix- and time-dependent change in the expression of stromal, vascular, and epithelial cell markers. These results indicate that stem cells isolated from debrided skin can be used as a single autologous cell source to develop a vascularized skin construct without culture expansion or addition of exogenous growth factors. This technique may provide an alternative approach for cutaneous coverage after extensive burn injuries.
    07/2012; 2012:841203. DOI:10.1155/2012/841203
    This article is viewable in ResearchGate's enriched format
  • Davin Mellus, Rodney K. Chan
    Perioperative Nursing Clinics 03/2012; DOI:10.1016/j.cpen.2011.10.006
  • [Show abstract] [Hide abstract]
    ABSTRACT: Oral incompetence following composite reconstruction of total and subtotal lower lip defects without any functioning lower lip muscle is a difficult problem for reconstructive surgeons. The authors retrospectively reviewed the use of a novel bilateral temporalis suspension technique for oral incompetence following lower lip reconstruction over a 10-year period. The timing of the reconstruction, cause of the defect, period of follow-up, and any complications were noted. Three cases of lower lip resuspension using bilateral temporalis flaps and fascia lata grafts were performed from 2000 to 2010. Two cases were secondary to burn trauma and one was from ballistic trauma. All patients underwent traditional means of reconstruction using free microvascular composite tissue transfer with and without fascial slings. All three patients presented with persistent lower lip incompetence. The average interval between the initial reconstructive operations and the resuspension operations was 1.6 years. All patients achieved dynamic oral competence at the first postoperative visit. At a mean follow-up of 3.6 years, all patients had maintained lower lip function. Dynamic lower lip resuspension with bilateral temporalis flaps and fascia lata grafts is an option for refractory lower lip drooping following total and subtotal loss, especially after conventional static reconstruction and without any functional orbicularis muscle. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.
    Plastic and Reconstructive Surgery 01/2012; 129(1):119-22. DOI:10.1097/PRS.0b013e31823620b0 · 3.33 Impact Factor
  • Journal of Oral and Maxillofacial Surgery 09/2011; 69(9). DOI:10.1016/j.joms.2011.06.174 · 1.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Locoregional breast cancer recurrence is a relatively rare event, occurring more frequently in patients diagnosed with more advanced stages of cancer and those with inflammatory features. While typical signs of recurrence after reconstruction include the development of a mass in the native skin or deep chest wall, oncologic relapse may also rarely be heralded by subtle cutaneous changes. This article describes a patient with inflammatory breast cancer who underwent neoadjuvant chemotherapy, mastectomy, radiation therapy, and hormonal therapy followed by delayed reconstruction with a deep inferior epigastric artery perforator flap and subsequently presented with a recurrence manifest as a localized rash over the upper abdomen. Surgeons who perform breast reconstruction should be attuned to both common and uncommon recurrence symptoms, as they may be the first to diagnose recrudescent disease.
    Annals of plastic surgery 03/2011; 66(3):233-4. DOI:10.1097/SAP.0b013e3181ee70b2 · 1.29 Impact Factor
  • Journal of Plastic Reconstructive & Aesthetic Surgery 02/2011; 64(5):e135-6. DOI:10.1016/j.bjps.2010.12.017 · 1.47 Impact Factor

Publication Stats

690 Citations
133.86 Total Impact Points


  • 2010–2015
    • U.S. Army Institute of Surgical Research
      Houston, Texas, United States
  • 2014
    • University of Texas Southwestern Medical Center
      Dallas, Texas, United States
  • 2013
    • Uniformed Services University of the Health Sciences
      베서스다, Maryland, United States
  • 2011–2012
    • Brooke Army Medical Center
      Houston, Texas, United States
  • 2006–2011
    • Brigham and Women's Hospital
      • • Division of Plastic Surgery
      • • Department of Surgery
      Boston, MA, United States
  • 2003–2010
    • Harvard Medical School
      • Department of Surgery
      Boston, Massachusetts, United States
  • 2004–2009
    • Harvard University
      Cambridge, Massachusetts, United States