Shun-Cheng Chang

Adipose-derived stem cells seeded on acellular dermal matrix grafts enhance wound healing in a murine model of a full-thickness defect.

IntroductionThe promotion of wound healing using dermal substitutes has become increasingly widespread, but the outcomes of substitute-assisted healing remain functionally deficient. Adipose-derived stem cells (ASCs) have been investigated widely in regenerative medicine and tissue engineering, and they have the potential to enhance wound healing. In this study, we focused on investigating the effects and mechanism of ASCs combined with an acellular dermal matrix (ADM) to treat full-thickness cutaneous wounds in a murine model. MethodsThe ADM was prepared from the dorsal skin of nude mice by decellularization by treatment with trypsin followed by Triton X-100. The human ASCs were isolated and cultured from abdominal lipoaspirate. We created a rounded, 8-mm, full-thickness cutaneous wound in nude mice and divided the mice into the following 4 groups: silicon sheet cover only, silicon sheet with spreading ASCs, ADM only, and ASCs seeded on ADM. The granulation thickness was evaluated by histology after 7 days. Further comparisons between the ADM only and ASC-seeded ADM groups were undertaken by assessing the reepithelialization ratio and blood vessel density at postoperative days 9 and 14. Statistical analyses were conducted using Student 2-tailed t test. Immunofluorescent histology and ASC labeling were also performed to identify possible mechanisms. ResultsThe ADM was successfully prepared, and the cytometry analysis and differentiation assay provided the characterization of the human ASCs. A marked improvement in granulation thickness was detected in the ADM-ASC group in comparison with other 3 groups. A significantly increased rate of reepithelialization in the ADM-ASC group (80 ± 6%) compared to the ADM only group (60 ± 7%) was noted on postoperative day 9. The blood vessel density was evidently increased in the ADM-ASC group (7.79 ± 0.40 vessels per field) compared to the ADM only group (5.66 ± 0.23 vessels) on day 14. Cell tracking experiments demonstrated that labeled ASCs were colocalized with staining for VEGF or endothelial cell maker vWF after the transplantation of ADM-ASCs on postoperative day 14. ConclusionsAdipose-derived stem cells seeded on an ADM can enhance wound healing, promote angiogenesis, and contribute to newly formed vasculature, and VEGF-expressing ASCs can be detected after transplantation. This model could be used to improve the other clinical applications of ASCs and to decipher the detailed mechanism by which ASCs interact with wound tissue.

Sensate first dorsal metacarpal artery flap for resurfacing extensive pulp defects of the thumb

Finding an appropriate soft-tissue grafting material to close a wound located over the distal phalanx of the thumb, especially the pulp region, can be a difficult task. A sensate first dorsal metacarpal artery flap, mobilized from the dorsum of the adjacent index finger and used as an island pedicle skin flap, can be useful for this purpose. The pedicle includes the ulnar branch of the first dorsal metacarpal artery, the dorsal veins, and the cutaneous branch of the radial nerve. Although this tiny artery is anatomically variable, safe dissection can be achieved by including the radial shaft periosteum of the secondary metacarpal bone and the ulnar head fascia of the first interosseous muscle. This approach has been used for 8 individuals with extensive pulp defects of the thumb over the past 3 years. Skin defects in all patients were combined with bone, joint, or tendon exposure. All flaps survived completely. This 1-stage procedure is reliable and technically simple. It provides sensate coverage to the pulp of the thumb but also avoids nerve repair or more complicated microsurgery.

The effect of hyperbaric oxygen and air on cartilage tissue engineering.

AbstractThere is an urgent need to develop tissue-engineered cartilage for patients experiencing joint malfunction due to insufficient self-repairing capacity of articular cartilage. The aim of this research was to explore the effect of hyperbaric oxygen and air on tissue-engineered cartilage formation from human adipose-derived stem cells seeding on the gelatin/polycaprolactone biocomposites. The results of histological analyses indicate that under hyperbaric oxygen and air stimulation, the cell number of chondrocytes in cartilage matrix was not significantly increased, but the 1,9-dimethylmethylene blue assay showed that the glycosaminoglycans syntheses markedly increased compared to the control group. In quantification real-time polymerase chain reaction results, the chondrogenic-specific gene expression of SOX9, aggrecan, and COL2A1 were compared respectively. Within the limitation of this study, it was concluded that 2.5 atmosphere absolute oxygen and air may provide a stress environment to help cartilage tissue engineering development.

Surgical treatment of gynecomastia: complications and outcomes.

Abstract Gynecomastia is defined as the benign enlargement of the male breast. Multiple surgical options have been used to improve outcomes. The aim of this study was to analyze the surgical approaches to the treatment of gynecomastia and their outcomes over a 10-year period. All patients undergoing surgical correction of gynecomastia in our department between 2000 and 2010 were included for retrospective evaluation. The data were analyzed for etiology, stage of gynecomastia, surgical technique, complications, risk factors, and revision rate. The surgical result was evaluated with self-assessment questionnaires. A total of 41 patients with 75 operations were included. Techniques included subcutaneous mastectomy alone or with additional ultrasound-assisted liposuction (UAL) and isolated UAL. The surgical revision rate for all patients was 4.8%. The skin-sparing procedure gave good surgical results in grade IIb and grade III gynecomastia with low revision and complication rates. The self-assessment report revealed a good level of overall satisfaction and improvement in self-confidence (average scores 9.4 and 9.2, respectively, on a 10-point scale). The treatment of gynecomastia requires an individualized approach. Subcutaneous mastectomy combined with UAL could be used as the first choice for surgical treatment of grade II and III gynecomastia.

Comparison of hatchet-shaped tensor fascia lata flap and pedicle anterior lateral thigh flap for treatment of trochanteric sores: a retrospective analysis of 48 patients.

PurposeSurgical reconstruction of trochanteric sores remains a formidable task for plastic surgeons. Diverse types of flaps have been proposed for use in this situation, each with particular advantages and limitations. This study aimed to compare the surgical outcomes between the hatchet-shaped tensor fascia lata (TFL) flap and the pedicle anterior lateral thigh (ALT) flap in treatment of trochanteric sores. MethodsForty-eight patients with trochanteric sores were operated on under spinal or general anesthesia using TFL or ALT flaps between August 2007 and November 2010. In the TFL group, 26 hatchet-shaped TFL musculocutaneous flaps were performed on 24 patients. In the ALT group, 25 pedicle ALT musculocutaneous flaps were performed on 24 patients. Surgical outcomes were retrospectively analyzed. ResultsNo significant difference was detected between the TFL and ALT groups in terms of age, preoperative disease period, obesity (body mass index), American Society of Anesthesiologists score, comorbidity, the defect size, follow-up time, and complication rate. The recurrence rate and the flap size were significantly higher in the TFL group than in the ALT group (P = 0.022; P < 0.001). The operation time was longer in the ALT group (P < 0.001). ConclusionsThe pedicle ALT flap is a more effective treatment than the TFL flap for the surgical management of trochanteric sores. The hatchet-shaped TFL flap should be reserved for the reconstruction of recurrent trochanteric sores or for use in the critically ill patient who cannot tolerate longer anesthesia and operation time.

The lower trapezius musculocutaneous flap for head and neck reconstruction: two decades of clinical experience.

BackgroundMicrosurgical free flap has gained the popularity over pedicle flap nowadays in the reconstruction of head and neck. However, pedicled flaps remain a promising alternative and have a remarkable position in selected patients. This review study aimed to determine the reliability and versatility of the lower trapezius musculocutaneous flap for reconstructing complex defects in the head and neck. MethodsBetween 1993 and 2012, 22 male and 10 female patients underwent a total of 32 lower trapezius flap reconstructions for complex defects that included neoplasm extirpation (n = 21), radionecrosis (n = 6), dehisced laminectomy (n = 2), pressure sore (n = 2), and necrotizing fasciitis (n = 1). The most common site of defect was the perioral region, followed by the neck, posterior skull, back, temporal region, shoulder, and the upper arm. Flap design was based on the defect size and location, as well as the ability to close the donor site primarily and to preserve muscle function. Outcome has been evaluated by the hospital course, postoperative morbidity, mortality, resultant cosmetics, and function at donor and recipient sites. ResultsStable wound coverage with total flap survival was achieved in 30 (93.75%) patients, 2 patients had partial flap necrosis which required flap reinsertion and skin graft coverage. All donor sites were closed primarily. Seroma developed in 2 (6.25%) patients, which were solved by needle aspiration. All muscle function was preserved. Eight patients died of their primary disease. ConclusionsFor selected patients who have advanced stage cancer, surgical sequelae after free flap surgery, unable to tolerate microsurgery, or special defect location, pedicled lower trapezius musculocutaneous flap provides efficient and effective reconstruction for complex defects especially in the head and neck.

The effects of microenvironment on wound healing by keratinocytes derived from mesenchymal stem cells

AbstractEmbryonic stem cells (ESCs) are pluripotent cells that can differentiate into various cell types, including keratinocyte-like cells, within suitable microniches. In this study, we aimed to investigate the effects of culture media, cell coculture, and a tissue-engineering biocomposite on the differentiation of mouse ESCs (MESCs) into keratinocyte-like cells and applied these cells to a surgical skin wound model. MESCs from BALB/c mice (ESC26GJ), which were transfected using pCX-EGFP expressing green fluorescence, were used to track MESC-derived keratinocytes. Weak expression of the keratinocyte early marker Cytokeratin 14 (CK-14) was observed up to 12 days when MESCs were cultured in a keratinocyte culture medium on tissue culture plastic and on a gelatin/collagen/polycaprolactone (GCP) biocomposite. MESCs cocultured with human keratinocyte cells (HKCs) also expressed CK-14, but did not express CK-14 when cocultured with human fibroblast cells (HFCs). Furthermore, CK-14 expression was observed when MESCs were cocultured by seeding HKCs or HFCs on the same or opposite side of the GCP biocomposite. The highest CK-14 expression was observed by seeding MESCs and HKCs on the same side of the GCP composite and with HFCs on the opposite side. To verify the effectiveness of wound healing in vivo, adipose-derived stem cells were applied to treat surgical wounds in nude mice. An obvious epidermis multilayer and better collagen deposition during wound healing were observed, as assessed by Masson staining. This study demonstrated the potential of keratinocyte-like differentiation from mesenchymal stem cells for use in promoting wound closure and skin regeneration.

Parasacral Perforator Flaps for Reconstruction of Sacral Pressure Sores.

BackgroundDespite advances in reconstruction techniques, pressure sores continue to present a challenge to the plastic surgeon. The parasacral perforator flap is a reliable flap that preserves the entire contralateral side as a future donor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior gluteal artery are still possible. We present our experience of using parasacral perforator flaps in reconstructing sacral defects. MethodsBetween August 2004 and January 2013, 19 patients with sacral defects were included in this study. All the patients had undergone surgical reconstruction of sacral defects with a parasacral perforator flap. The patients’ sex, age, cause of sacral defect, flap size, flap type, numbers of perforators used, rotation angle, postoperative complications, and hospital stay were recorded. ResultsThere were 19 parasacral perforator flaps in this series. All flaps survived uneventfully except for 1 parasacral perforator flap, which failed because of methicillin-resistant Staphylococcus aureus infection. The overall flap survival rate was 95% (18/19). The mean follow-up period was 17.3 months (range, 2–24 months). The average length of hospital stay was 20.7 days (range, 9–48 days). No flap surgery-related mortality was found. Also, there was no recurrence of sacral pressure sores or infected pilonidal cysts during the follow-up period. ConclusionsPerforator-based flaps have become popular in modern reconstructive surgery because of low donor-site morbidity and good preservation of muscle. Parasacral perforator flaps are durable and reliable in reconstructing sacral defects. We recommend the parasacral perforator flap as a good choice for reconstructing sacral defects.

Bipedicled flap for the reconstruction of soft tissue defects of the Achilles tendon.

AbstractSoft tissue defects exposing the Achilles tendon are common in patients who have undergone trauma or in those with pressure ulcers associated with vascular diseases. The purpose of this article was to present our experience of 11 patients who underwent reconstruction of soft tissue defects of the Achilles tendon using bipedicled fasciocutaneous flaps. Between August 2008 and August 2012, 11 patients were admitted to our hospital, presenting with soft tissue defects overlying the Achilles tendon. After adequate debridement, the 11 patients underwent bipedicled fasciocutaneous flap placement to resurface the complex soft tissue defects and provide a gliding surface for the exposed Achilles tendon. The patients’ age, comorbidity, etiology, defect size and location, wound culture, skin graft size, complications, surgery duration, and follow-up period were reviewed. The 11 fasciocutaneous bipedicled flaps survived completely, and the wounds healed satisfactorily at a mean follow-up period of 20.9 months (range, 6-48 months). Only 1 flap was complicated with wound dehiscence and superficial necrosis of its lateral edge, which healed conservatively. The donor sites were covered with split-thickness skin grafts and healed well without complications. The bipedicled fasciocutaneous flap is a reliable flap for coverage of defects overlying the Achilles tendon, especially in patients with vascular problems and/or elderly patients. The ease of handling, short operative time, and early recovery of mobilization function are of great benefit to patients. Thus, the bipedicled fasciocutaneous flap can be a valuable alternative for defect reconstructions overlying the Achilles tendon, with satisfactory results both functionally and cosmetically.

Partial Calcanectomy Facilitates Wound Closure of Heel Defects in High-Risk Patients.

BackgroundHeel ulcers in patients with severe peripheral artery occlusive disease represent a challenge to the treating physician. They become more difficult to treat with underlying medical comorbidities. The purpose of this report is to document evidence that partial calcanectomy is simple to perform and clears infected bone, tissue, and ulceration. MaterialsBetween July 2011 and August 2013, 30 consecutive patients presented to our department with heel wounds caused by diabetes mellitus and pressure. After evaluation by a vascular surgeon, 12 patients diagnosed with near total occlusive peripheral vascular disease were included in this report. Of the 12 patients, 7 were women. Their ages ranged from 65 to 79 years (mean, 73.3 years). After admission, surgical debridement was performed emergently with subsequent partial calcanectomy and wound closure. ResultsEight heel wounds (75%) healed completely with no further surgery to achieve defect coverage. Wound dehiscence developed in 4 patients (25%). The mean number of debridements was 1.75 (range, 1–3) with a total operation time of 71.5 minutes (range, 45–114 min). One patient died of acute myocardial infarction 2 weeks after discharge. The mean length of hospital stay was 8.3 days (range, 5–16 days). ConclusionIn this study, we demonstrate that partial calcanectomy is practical for the treatment of plantar heel ulcers in patients with severe comorbidities. With proper surgical planning and postoperative care, partial calcanectomy is a viable alternative to below-the-knee amputation and may better serve the patient who would otherwise be restricted to a sedentary lifestyle.