Rodney Chan

Deep inferior epigastric artery perforator (DIEP) flap is an excellent option for breast reconstruction in young and active patients who have a history of chest wall radiation. One drawback, however, is that the entire capacity of abdominal pannus cannot be reliably transferred on a single pedicle. The purpose of this case report is to demonstrate a method of maximizing the volume of reconstruction with a dual-pedicled DIEP flap. A case is reported in which both antegrade and retrograde internal mammary vessels were used as recipient sites for a dual-pedicled, folded, stacked DIEP flap. Good flows were observed in both sets of recipient vessels intraoperatively. Postoperative imaging revealed patent vascular anastomoses of both pedicles. At 1-year follow-up, there was no evidence of fat necrosis and a satisfactory aesthetic outcome was achieved. To maximize the volume of the reconstructed breast, the entire abdominal pannus can be utilized. The retrograde limb of internal mammary ve...

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.

The injury caused by reperfusion of ischemic skeletal muscle is mediated by the membrane attack complex of complement (C) . This C activation results from local classical pathway activation after deposition of IgM in injured muscle, an event analogous to C deposition in the mucosa of the gut during reperfusion . Our past analysis has indicated that the injury is not uniform even within a single microscopic section. This study was performed to elucidate the exact site of IgM and C deposition on muscle injured by ischemia and reperfusion. C57Bl/6 mice were subjected to 2 h of tourniquet-induced hindlimb ischemia followed by reperfusion for 0-6 h. Three muscle groups (vastus, gastrocnemius, and soleus) of varying fast-myosin content were compared for muscle fiber damage and C deposition. Adjacent paraffin-embedded cross-sections were immunostained to correlate C3 deposition with muscle fiber type as defined by monoclonal antibodies. Muscle injury after ischemia and reperfusion is not u...

The parathyroid hormone (PTH) content of tissue aspirates is an accurate indicator of parathyroid tissue and can replace frozen section during parathyroid surgery. Prospective data collection in a tertiary care hospital with a single surgeon. One hundred sixty-seven consecutive patients completing limited parathyroid explorations. Parathyroid adenomas removed during limited parathyroid exploration were aspirated through a 22-gauge needle into 0.5 mL isotonic sodium chloride solution and the solution held on ice in a purple-top tube. Aspirates of in situ thyroid tissue were also taken for comparison. Samples were then assessed to monitor the physiologic impact of the surgery. The PTH content of tissue aspirates was compared with histologic identification of removed putative parathyroid tissue. Elevated tissue PTH content was associated with the identification of origin as parathyroid in every case. Tissue aspirates from pathologically proven parathyroid tissue had a mean PTH level of...

Ischemia with subsequent reperfusion (IR) injury is a significant clinical problem that occurs after physical and surgical trauma, myocardial infarction, and organ transplantation. IR injury of mouse skeletal muscle depends on the presence of both natural IgM and an intact C pathway. Disruption of the skeletal muscle architecture and permeability also requires mast cell (MC) participation, as revealed by the fact that IR injury is markedly reduced in c-kit defective, MC-deficient mouse strains. In this study, we sought to identify the pathobiologic MC products expressed in IR injury using transgenic mouse strains with normal MC development, except for the lack of a particular MC-derived mediator. Histologic analysis of skeletal muscle from BALB/c and C57BL/6 mice revealed a strong positive correlation (R(2) = 0.85) between the extent of IR injury and the level of MC degranulation. Linkage between C activation and MC degranulation was demonstrated in mice lacking C4, in which only li...

Complement is an important mediator of the injuries observed after skeletal muscle ischemia and subsequent reperfusion. Although the classical pathway had been assumed to be the major pathway of activation leading to injury, the mannose-binding lectin (MBL) pathway might also play a contributing role. In this study, we found that MBL-deficient mice had significant protection after skeletal muscle reperfusion injury compared with wild-type, classical pathway-specific C1q-deficient mice, or MBL-deficient mice reconstituted with recombinant human MBL. MBL-deficient mice, however, were not protected from permeability edema or secondary lung injury after ischemia-reperfusion. These data indicate that blockade of the classical pathway alone (C1q) is protective against permeability edema and remote pulmonary injury but not protective against histologic muscle injury. In contrast, blocking the MBL pathway alone protects against histological injury but is not protective against permeability ...

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 im...

The injury sustained by reperfused skeletal muscle is inflammatory and is initiated by binding of pre-formed IgM to involved tissue, followed by local complement activation and further inflammation. A clone of natural IgM has been described that initiates this injury, suggesting that specific antigens are exposed on ischemic tissues that act as ligands for this pathogenic antibody. In these experiments, we examine the properties of short peptide sequences, and their homologues, that bind to the antigen-combining site of this pathogenic IgM clone. A 12-mer phage display library was biopanned with the pathogenic IgM clone and then negatively selected against an inactive natural IgM clone. All 8 clones that bound specifically to the pathogenic IgM had closely related amino acid sequences. P8 is the clone that bound most avidly. Tissue lysates from ischemic tissue were reacted with pathogenic IgM, and immune complexes isolated and analyzed on SDS-PAGE. Bands were excised and sequenced, identifying non-muscle myosin as the protein reacting with pathogenic antibody in ischemic gut and glycogen phosphorylase as the counterpart in ischemic skeletal muscle. Both proteins contain sequence homologous to P8; N2 and GP1 are the natural 12-mers homologues that are contained within non-muscle myosin and glycogen phosphorylase, respectively. Wild-type C57/Bl6 mice, divided into groups receiving saline, P8, N2, GP1, or a random peptide at the start of the experiment, were subjected to 2 hours of tourniquet induced hind limb ischemia and 3 hours of reperfusion. Muscle was assessed for injury with histology and for immune activation with histochemistry. Intravenous administration of P8, N2, and GP1 led to significant attenuation of muscle injury (13 +/- 1.8 injured fibers/50 counted, 12 +/- 0.81, 8.0 +/- 0.73 respectively) after reperfusion injury compared to animals receiving saline (26 +/- 2.3) or the same mass of a random peptide (22 +/- 2.3), P less than .05. This level of protection from injury is comparable to that seen in the absence of antibody altogether. As well, P8-treated animals exhibited a marked decrease in deposition of IgM (as well as C3) in comparison to saline treated controls. Specific peptide blockade of an injury-inducing IgM clone decreased the local consequences of skeletal muscle ischemia/reperfusion injury in wild-type animals that have the full repertoire of IgM specificities. This indicates that the antibodies that initiate reperfusion injury have specificity only for P8-related antigens. This could also indicate that the variety of relevant ischemic antigens is quite restricted.

Background. Skeletal muscle reperfusion injury is mediated by IgM natural antibodies and by comple- ment activation, as shown by the attenuation of reper- fusion injury seen in mice with no natural IgM (1) and in mice deficient in complement C3 and C4 (2). We postulate that tissue, when ischemic, expresses neoan- tigens to which preformed natural IgM antibodies bind, in

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.

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.

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. Therapeutic, V.

Ischemia with subsequent reperfusion (IR) injury is a significant clinical problem that occurs after physical and surgical trauma, myocardial infarction, and organ transplantation. IR injury of mouse skeletal muscle depends on the presence of both natural IgM and an intact C pathway. Disruption of the skeletal muscle architecture and permeability also requires mast cell (MC) partici- pation, as revealed by

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 indepen...

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 oxy...

Murine hindlimb reperfusion injury (I/R), is initiated by activation of the classical pathway of complement. Complement receptor-2 knockout mice (Cr2-/-) are protected from I/R injury due to defective B-1 cells with a resulting deficient natural immunoglobulin M (IgM) repertoire. Cr2-/- and wild type (WT) mice were studied to isolate the antibody or antibodies responsible for initiation of I/R. IgM-secreting B-1 cell clones were produced with hybridoma technology from WT cells. Of 21 clones tested in murine I/R models, only 1 clone, CM22, was found to restore injury in protected mice. Cr2-/- mice reconstituted with IgM from individual clones, WT serum, or saline were subjected to 2 hours hindlimb ischemia and 3 hours reperfusion and compared with WT. Muscle injury in Cr2-/- mice reconstituted with CM22 was similar to injury in WT mice reconstituted with saline and Cr2-/- mice reconstituted with WT serum. This injury was 137% greater (P < .05) than in both Cr2-/- mice reconstituted with saline and those reconstituted with a different IgM clone, CM31. IgM and C3 deposition was found only on injured muscle of WT mice or Cr2-/- mice reconstituted with CM22 or WT serum. A single clone of self-reactive IgM, CM22, can initiate complement-dependent I/R injury.

The increased focus on quality and efficiency improvement within academic surgery has met with variable success among plastic surgeons. Traditional surgical performance metrics, such as morbidity and mortality, are insufficient to improve the majority of today's plastic surgical procedures. In-process analyses that allow rapid feedback to the surgeon based on surrogate markers may provide a powerful method for quality improvement. The authors reviewed performance data from all bilateral reduction mammaplasties performed at their institution by eight surgeons between 1995 and 2007. Multiple linear regression analyses were conducted to determine the relative impact of key factors on operative time. Explanatory learning curve models were generated, and complication data were analyzed to elucidate clinical outcomes and trends. A total of 1068 procedures were analyzed. The mean operative time for bilateral reduction mammaplasty was 134 +/- 34 minutes, with a mean operative experience of 11 +/- 4.7 years and total resection volume of 1680 +/- 930 g. Multiple linear regression analyses showed that operative time (R = 0.57) was most closely related to surgeon experience and resection volume. The complication rate diminished in a logarithmic fashion with increasing surgeon experience and in a linear fashion with declining operative time. The results of this study suggest a three-phase learning curve in which complication rates, variance in operative time, and operative time all decrease with surgeon experience. In-process statistical analyses may represent the beginning of a new paradigm in academic surgical quality and efficiency improvement in low-risk surgical procedures.

Aplasia cutis congenita is failure of development of all layers of the skin. This condition most commonly affects the scalp and is typically an isolated finding. In rare instances, it can affect other anatomic sites and may be associated with syndromes or other causes. We discuss an infant born with extensive aplasia cutis congenita of the trunk related to twin fetal demise (fetus papyraceous). Conservative management with moist dressings led to satisfactory healing.

Burns, especially those involving large surface areas, represent a complex wound healing problem. Platelet-derived growth factor (PDGF) is released by activated platelets to recruit inflammatory cells toward the wound bed. It has effects on promoting angiogenesis and granulation tissue formation. However, the effectiveness of topical PDGF on wound closure is variable, ranging from little improvement observed in pig models to dramatic improvement reported in a diabetic mouse model. Here, we sought to determine the effectiveness of commercially sold PDGF-BB (Regranex) on wound closure in genetically diabetic mice. C57BL/KsJ db+/db+ mice and its host strain bearing dorsal 1.5-cm wounds were divided into groups (n = 8 in each group) receiving topical application of either Regranex (10 microg/wound) or vehicle for 5 consecutive days after wounding. The rate of wound closure was analyzed using computerized planimetry. The amount of granulation tissue was determined histologically. Our data indicate that diabetic mice exhibit a significant delay in wound closure when compared with their host strain. Topical application of Regranex did not improve the time to wound closure but did significantly increase the amount of granulation tissue. Our current study using commercially available Regranex failed to reproduce the previously reported finding that PDGF improved wound closure in healing impaired genetically diabetic mice.

To determine whether a highly visible device that clearly indicates whether the head-of-bed is adequately elevated would increase rates of compliance with head-of-bed elevation guidelines. A prospective, single-center, multi-unit, two-phase study. Surgical, thoracic, trauma, and medical intensive care units. Cohort of intubated patients. A 4-wk trial was performed. At the onset of the trial, nurses were reminded to maintain head-of-bed elevation > 30 degrees. Over the subsequent 2 wks, head-of-bed elevations of intubated patient beds were measured. An Angle Indicator, designed to clearly display whether the head-of-bed was adequately elevated, was then placed on side rails of beds of ventilated patients, and head-of-bed elevation measurements were taken for an additional 2 wks. A survey was then handed out to nursing staff to assess satisfaction with the device. A total of 268 bed measurements were made. The average head-of-bed elevation was 21.8 degrees on beds without the device (n = 166) and 30.9 degrees on beds with the device (n = 102; p < .005). When compliance is defined as a bed angle of > or = 28 degrees, 23% of beds without the device were compliant while 71.5% of the beds with the device were compliant. The relative risk and odds ratio of having the device on a compliant bed were 2.2 and 9.25, respectively (p < .005). Seventy-two percent of nurses surveyed (n = 32) found it to be an improvement over existing methods, 88% found it helpful, and 84% would like it routinely used. The Angle Indicator improved rates of adherence to bed-elevation guidelines, and hospital staff found it helpful.

Reperfusion injury is a common clinical problem that lacks effective therapy. Two decades of research implicating oxygen free radicals and neutrophils has not led to a single successful clinical trial. The aim was to review new clinical and preclinical data pertaining to the alleviation of reperfusion injury. A review of the literature was undertaken by searching the MEDLINE database for the period 1966-2003 without language restrictions. Evidence now points to complement and immune complexes as critical players in mediating reperfusion injury. Ischaemia is postulated to induce a phenotypical cellular change through the surface expression of a neoantigen. Preformed circulating natural IgM antibodies are then trapped and complement is activated. Final events leading to reperfusion injury include formation of the membrane attack complex and mast cell degranulation.

Patients with primary hyperparathyroidism and negative preoperative localization imaging have a different outcome than patients with positive imaging. Prospective single-surgeon case series. Referral center. Forty-two patients with primary hyperparathyroidism, indications for surgery, and both cervical ultrasonographic results and technetium Tc 99m sestamibi nuclear images that were nonlocalizing over a 5- year span. Extent of surgery required to produce cure; operative findings. Of 430 patients undergoing surgery for primary hyperparathyroidism, 351 underwent both ultrasonographic and sestamibi imaging. Among 351 patients, the imaging results of 42 patients did not show an adenoma, and these patients underwent cervical exploratory surgery. Of 42 patients, 41 were cured at a mean follow-up of 90 days; 1 patient underwent surgical reexploration and was cured by removal of a mediastinal adenoma. To achieve initial cure, 12 of 42 patients (28.6%) required partial thyroidectomy, 9 (21.4%) required partial thymectomy, 17 (40.5%) required paratracheal dissection to access or devascularize an obscure adenoma. Pathologic examination disclosed single adenoma in 26 of 42 patients (61.9%), parathyroid hyperplasia in 14 (33.3%), and double adenoma in 2 (4.8%). Patients whose preoperative localization studies fail to localize solitary adenoma commonly require extensive surgery to cure hyperparathyroidism. Lack of localization may be a reasonable criterion on which to base referral of the patient to a high-volume medical center.