Influence of the Tissue Collection Procedure on the Adipogenic Differentiation of Human Stem Cells: Ischemic versus Well-Vascularized Adipose Tissue.

Clinical and basic science applications using adipose-derived stem cells (ADSCs) are gaining popularity. The current adipose tissue harvesting procedures introduce nonphysiological conditions, which may affect the overall performance of the isolated ADSCs. In this study, we elucidate the differences between ADSCs isolated from adipose tissues harvested within the first 5 min of the initial surgical incision (well-vascularized, nonpremedicated condition) versus those isolated from adipose tissues subjected to medications and deprived of blood supply during elective free flap procedures (ischemic condition). ADSCs isolated from well-vascularized and ischemic tissues positively immunostained for several standard stem cell markers. Interestingly, the percent change in the CD36 expression for ADSCs isolated from ischemic versus well-vascularized tissue was significantly lower in males than females (p < 0.05). Upon differentiation and maturation to adipocytes, spheroids formed using ADSCs isolated from ischemic adipose tissue had lower triglyceride content compared to those formed using ADSCs isolated from the well-vascularized tissue (p < 0.05). These results indicate that ADSCs isolated from ischemic tissue either fail to uptake fatty acids or fail to efficiently convert those fatty acids into triglycerides. Therefore, more robust ADSCs suitable to establish in vitro adipose tissue models can be obtained by harvesting well-vascularized and nonpremedicated adipose tissues.

Use of Nerve Transfer Procedures for Motor and Sensory Restoration of a High Median Nerve Injury.

High median nerve (HMN) injuries are unusual clinical conditions, but they generate significant disability of the affected extremities to perform even basic activities of daily living. Even though they can display different degrees of dysfunction due to overlapping innervation and musculature compensation, an early assessment of the existing functional deficits and a timely surgical approach can optimize the long-term outcome. The use of distal nerve transfer procedures has gained popularity since they reduce the distance between the injured zone and the disrupted targets, accelerate the nerve regeneration and subsequently optimize the postoperative motor and sensory recovery. This report describes a patient with a significant segmental loss of the median nerve at the upper third of the left arm after a motor vehicle accident that caused multiple other injuries. The motor deficit of this injury was managed soon after the admission with extensor carpi radialis brevis (ECRB) nerve transfer to the anterior interosseous nerve (AIN). Subsequently, double side-to-side cross-palm nerve allografts between the ulnar and median nerves were utilized to restore the sensory deficit of the HMN lesion. An important functional improvement was obtained with these nerve transfer procedures, and the patient successfully returned to the workforce without limitations. Other surgical options for motor and sensory reconstruction are briefly reviewed.

Management of Severe Multifactorial Eyelid Ectropion With Lateral Tarsal Strip Procedure and Full-Thickness Skin Graft.

Secondary ectropion is a relatively common anatomo-functional abnormality of the lower eyelids. They can be seen in numerous clinical settings and generate disabling symptoms and even severe complications such as corneal ulceration, globe perforation, and blindness. Based on their etiology, cases of secondary ectropion are grouped into involutional, paralytic, cicatricial, and mechanical. Multiple techniques have been developed to treat specific abnormalities associated with this condition. Therefore, a comprehensive local assessment is crucial to select one or more surgical procedures for each particular situation. This report describes a patient with multiple contributing factors for severe ectropion of left lower eyelid treated with lateral tarsal strip procedure and full-thickness skin graft. Other surgical options and their indications are briefly reviewed.

Surgical management of giant acne keloidalis nuchae lesions.

Acne keloidalis nuchae (AKN) is a progressive inflammatory condition that affects posterior neck and occiput. Treatment options include antibiotics, steroids, lasers, radiotherapy and surgery. We present three patients with advanced 'tumor-stage' AKN that underwent radical local excision followed by either immediate or delayed skin resurfacing, and briefly review existing literature.

Immediate allograft reconstruction of the infraorbital nerve following resection of polyostotic fibrous dysplasia lesion.

Processed nerve allografts (PNA) have increasingly been used as alternative to autogenous nerve grafts to repair nerve injuries in oral-maxillofacial surgeries. This case report describes an immediate PNA reconstruction of infraorbital nerve injury sustained during the ablation of a large expansile polyostotic fibrous dysplasia centered in the left maxilla.

Ameloblastoma: clinical presentation, multidisciplinary management and outcome.

We studied 21 patients who underwent radical ameloblastoma excision followed by immediate reconstruction. Comorbidities, consumption of alcohol and/or tobacco and BMI status did not contribute to an unfavorable outcome. Giant ameloblastoma (≥5 cm) and/or tumor involving bony curvatures increased surgical complexity, the incidence of complications and hospital stay.

Use of cervicothoracic rotation flap and osteocutaneous radial forearm free flap for a complex multilayered cheek defect reconstruction.

We report the combination of osteocutaneous radial forearm free flap and extensive cervicothoracic flap to reconstruct a large through-and-through cheek and mandibular defect. In patients with difficult clinical settings, this approach reduces operative time and complications without compromising the functional and cosmetic outcomes.

Closed Incisional Negative Pressure Wound Therapy Sponge Width and Tension Off-Loading: A Laboratory Model.

Closed incisional negative pressure wound therapy (ciNPWT) has become commonplace in surgery. One mechanism ciNPWT may prevent incision site complications is by off-loading tension. This study aimed to find what width sponge using ciNPWT provides the most tension off-loading.A model was designed to test tension off-loading of a wound using ciNPWT. An incision was made in an anatomy model and closed with single stitch at the central axis. Force was applied tangentially using a force gauge at a steady rate until the wound dehisced at a peak force indicated by the 5-0 suture breaking. This was repeated 10 times for the following 4 trials: no ciNPWT and ciNPWT sponges cut a 3-, 6-, and 9-cm widths with 125 mm Hg of negative pressure.The mean peak force to dehisce the wound without ciNPWT was the lowest, 28.7 N. The mean force for the ciNPWT trials was 43.0, 38.7, and 36.4 N for V.A.C. sponges of 3, 6, and 9 cm in width, respectively. There was a statically significant difference among all the trials using one-way analysis of variance with Tukey posttest analysis with a P value of less than 0.0001.Closed incisional negative pressure wound therapy was shown to increase peak force required to dehisce an incision of up to 49.7% compared with closure without. There is an inverse relationship with sponge width and tension off-loading. The smaller the sponge, the more tension is off-loaded across the incision. Closed incisional negative pressure wound therapy with a 3-cm-wide sponge required the greatest peak force for dehiscence.

An unusual and delayed complication of hyaluronic acid filler injection: a case report.

48-year-old female with facial granulomatous nodules and fungal/bacterial infection after hyaluronic acid injection. She underwent anti-fungal/antibacterial therapy and local excision. The proposed mechanisms include inflammatory foreign body reaction and pathogen contamination. Providers must exercise caution with the use of facial fillers and demonstrate expertise in avoiding and managing potential complications.

Modified bridle tendon transfer procedure following a complete musculature loss of the anterior leg compartment: Case report and literature review.

The complete musculature loss of the anterior compartment of the leg is a rare complication that occurs as a result of local tissue damage, intracompartmental bleeding and ischemia-reperfusion events. It causes foot drop and equinovarus deformity that negatively impact the quality of life of affected patients. This report describes a modified bridle tendon transfer procedure to correct this defect in a case of extensive muscle necrosis secondary to local hemorrhage. A review of the literature was carried out to elucidate the benefits and risks associated to this technique.

Management of two major postoperative bleeding complications after mandible reconstruction with fibula free flap in a patient under chronic warfarin treatment.

We present a case of two separated life-threatening postoperative bleeding complications after mandible cancer resection and microsurgical fibula flap in a patient under permanent warfarin treatment. We used fresh frozen plasma, prothrombin complex concentrate to control bleedings. We consider to maintain similar patients in heparin/enoxaparin bridging for 1-2 weeks.

Total Nose and Upper Lip Replantation: A Case Report and Literature Review.

The nose plays a critical role in olfaction, air filtration and humidification, and facial aesthetics. Most nasal amputations result from animal bites, human bites, and lacerations from glass. Successful replantation yields the best aesthetic and functional outcomes and is preferred compared with multistage nasal reconstruction. However, nasal replantation is technically challenging; establishing venous outflow can be particularly difficult. A 17-year-old male sustained a complete nose and upper lip amputation in a motor vehicle accident. The midface segment was emergently replanted. Two arteries (left dorsal nasal artery, left superior labial artery) and 1 vein (branch of the left supratrochlear artery) were anastomosed using microsurgical technique. A vein graft, systemic anticoagulation, and postoperative leeching were important adjuncts. Total operative time was 10 hours. Cold ischemia time was 2 hours and warm ischemia time was 1 hour. Two arteries were anastomosed to minimize the risk of ischemia of the nose and/or upper lip. Complete survival of the replanted segment was achieved. Eighteen months postoperatively, the patient has bilateral nasal patency, intact septal support, and an excellent aesthetic result. All efforts should be made to establish a venous anastomosis during nasal replantation to maximize functional and aesthetic outcomes. Partial necrosis is common following artery-only replantation, leading to tissue loss and contracture.

Important Developments in Burn Care.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Explain the epidemiology of severe burn injury in the context of socioeconomic status, gender, age, and burn cause. 2. Describe challenges with burn depth evaluation and novel methods of adjunctive assessment. 3. Summarize the survival and functional outcomes of severe burn injury. 4. State strategies of fluid resuscitation, endpoints to guide fluid titration, and sequelae of overresuscitation. 5. Recognize preventative measures of sepsis. 6. Explain intraoperative strategies to improve patient outcomes, including hemostasis, restrictive transfusion, temperature regulation, skin substitutes, and Meek skin grafting. 7. Translate updates in the pathophysiology of hypertrophic scarring into novel methods of clinical management. 8. Discuss the potential role of free tissue transfer in primary and secondary burn reconstruction. SUMMARY: Management of burn-injured patients is a challenging and unique field for plastic surgeons. Significant advances over the past decade have occurred in resuscitation, burn wound management, sepsis, and reconstruction that have improved outcomes and quality of life after thermal injury. However, as patients with larger burns are resuscitated, an increased risk of nosocomial infections, sepsis, compartment syndromes, and venous thromboembolic phenomena have required adjustments in care to maintain quality of life after injury. This article outlines a number of recent developments in burn care that illustrate the evolution of the field to assist plastic surgeons involved in burn care.

Modified Meek Micrografting Technique for Wound Coverage in Extensive Burn Injuries.

The modified Meek micrografting technique constitutes a rapid and efficient surgical approach for the skin coverage of extensive full-thickness burn injuries. A total of 10 burn patients (mean 68 ± 9.2% TBSA) admitted to our burn unit required one or more Meek micrografting procedures (mean 2.2 ± 0.5) to cover in average 43.4 ± 11.6% TBSA (range between 10 and 75% TBSA). This goal was achieved using a donor site area ranging between 2.5 and 18% TBSA. All patients developed local infection to Pseudomona aeruginosa (75%), Stenotrophomona maltophilia (25%), methicillin-resistant Staphylococcus aureus (12.5%), and Acinetobacter baumannii (12.5%). Thus, the average of Meek regrafting after graft-take failure was 13.1 ± 6.4% TBSA (median: 9%; range from 0 to 36%). The period to obtain stable definitive wound closure was in average of 67.2 ± 21 days post injury. The modified Meek micrografting provides a reliable and versatile method for the coverage of large burn wounds with limited autograft donor sites and is now routinely used in our institution. Its systematic use improves operating times and overall outcomes reducing the number of surgeries, increasing the percentage of graft take, and decreasing the length of stay.

Fibrocytes participate in the development of heterotopic ossification.

Heterotopic ossification (HO) is a complication of musculoskeletal injury characterized by the formation of mature bone in soft tissues. The etiology of HO is unknown. We investigated the role of bone marrow derived progenitor cells in HO pathophysiology. We isolated the cells from HO specimens by cell explantation. Using flow cytometry and immunofluorescence microscopy, we found that 35 to 65% of the HO cells exhibit a bone marrow derived fibrocyte profile consisting in spindle-shaped morphology associated with type 1 pro-collagen and LSP1 expression. When cultured in osteogenic differentiation medium, active machinery for bone mineralization (high gene expression of Anx2, TNAP, and Pit-1), and calcium/phosphate deposits were found. Interestingly, interferon-alpha 2b significantly reduced the proliferation rate and COL1 gene expression in HO cells. We have characterized a novel subset of bone marrow derived progenitor cells in the HO specimens. The findings from this research study will provide new insights into the development of HO in burn patients.

Characterization of heterotopic ossification in burn patients.

Heterotopic ossification (HO) is a clinical condition of ectopic bone formation in soft tissue. This clinical entity has been associated with genetic disorders, traumatic injuries, and musculoskeletal surgeries. In this regard, functional impairments secondary to scar contractures seen in burn injuries may be exacerbated with underlying HO. The appropriate prevention or management of this complication is crucial to optimize outcome in burn patients. This clinical study reviews the incidence of HO in our burned patients, diagnostic methods, therapeutic approaches including surgical timing and techniques.

Deep dermal fibroblast profibrotic characteristics are enhanced by bone marrow-derived mesenchymal stem cells.

Hypertrophic scars are a significant fibroproliferative disorder complicating deep injuries to the skin. We hypothesize that activated deep dermal fibroblasts are subject to regulation by bone marrow-derived mesenchymal stem cells (BM-MSCs), which leads to the development of excessive fibrosis following deep dermal injury. We found that the expression of fibrotic factors was higher in deep burn wounds compared with superficial burn wounds collected from burn patients with varying depth of skin injury. We characterized deep and superficial dermal fibroblasts, which were cultured from the deep and superficial dermal layers of normal uninjured skin obtained from abdominoplasty patients, and examined the paracrine effects of BM-MSCs on the fibrotic activities of the cells. In vitro, deep dermal fibroblasts were found higher in the messenger RNA (mRNA) levels of type 1 collagen, alpha smooth muscle actin, transforming growth factor beta, stromal cell-derived factor 1, and tissue inhibitor of metalloproteinase 1, an inhibitor of collagenase (matrix metalloproteinase 1). As well, deep dermal fibroblasts had low matrix metalloproteinase 1 mRNA, produced more collagen, and contracted collagen lattices significantly greater than superficial fibroblasts. By co-culturing layered fibroblasts with BM-MSCs in a transwell insert system, BM-MSCs enhanced the fibrotic behavior of deep dermal fibroblasts, which suggests a possible involvement of BM-MSCs in the pathogenesis of hypertrophic scarring.

Strategies to increase flap survival in nasal reconstruction in patients with deep panfacial burns.

Total nasal reconstruction requires the management of skin, cartilage, and nasal mucosa. This three-dimensional surgical approach is especially restricted in patients with severe deformities after deep panfacial burns. In this regard, the development of tissue fibrosis reduces the quality and reliability of surrounded donor sites, limiting the surgical options and flap survival outcomes. This report discusses the benefit of tissue protection procedures, such as flap delay and leech therapy, in the total nasal reconstruction of a patient with split-thickness skin grafts on donor sites for forehead and nasolabial flaps.

Reprogrammed fibrocytes induce a mixed Th1/Th2 cytokine response of naïve CD4(+) T cells.

Naïve CD4(+) T cells develop different effector T cells and cytokine profiles after antigenic stimulation. It has been previously documented that fibrocytes function as antigen presenting cells inducing proliferation as well as Th2 cytokine response in naïve CD4(+) T cells. Our group has reported that several circulating cell types recruited to the wound site can be transformed into anti-fibrotic profile cells, which subsequently induce MMP-1 stimulation in dermal fibroblasts. Here, we report how similar reprogramming pathway of fibrocytes could modify the CD4(+) T cell response. Our findings confirmed that reprogrammed fibrocytes induce CD4(+) T cell activation with a mixed Th1/Th2 cytokine response. Since a reciprocal positive feedback between Th2 cells and fibrocytes exist to amplify and perpetuate the pro-fibrotic stimulation in dermal fibroblasts, the novel transdifferentiation of regular mature fibrocytes into reprogrammed fibrocytes appears to be a promising strategy to reverse the Th2 cytokine overproduction, and subsequently control the local fibrogenesis.

Fibrocytes can be reprogrammed to promote tissue remodeling capacity of dermal fibroblasts.

Fibroblasts play a pivotal role in wound healing process participating in both tissue fibrosis and remodeling. However, it remains unclear which factors activate such diversity of fibroblast responses and how this decision-making process is made. Previous reports have demonstrated that wound milieu stimulates the transformation of circulating precursor cells into fibrocytes. These pro-fibrogenic cells promote the collagen production by resident fibroblasts. Conversely, recruited cells with anti-fibrogenic profile that can compete with fibrocytes have not been identified. This report describes a novel transdifferentiation process of fibrocytes induced by changing culture conditions. The reprogrammed fibrocytes markedly increased cell proliferation and MMP-1 expression in dermal fibroblasts. The MMP-1 up-regulation was directly related to the number of fibrocytes that followed this cell transformation. In vitro and in vivo results have confirmed that TGF-ß deprivation plays an important role in this novel fibrocyte differentiation pathway. Our findings demonstrate that, changing the fibrocyte commitment, it is possible to exponentially stimulate the tissue remodeling capacity of dermal fibroblasts. These results will open new research approaches to understand the role of cell transdifferentiation and local environment not only in the wound healing process of skin, but also in several other fibrocyte-associated diseases such as lung fibrosis, asthma, liver cirrhosis, chronic pancreatitis, and atherosclerosis.