Won Jai Lee

Correlation of neotongue volume changes with functional outcomes after long-term follow-up of total glossectomy.

As the survival rate of tongue cancer has increased, longer-term results of tongue reconstruction are also being considered. The aim of this study was to report the long-term outcomes of total glossectomy. Of 14 patients who underwent total glossectomy, 11 were reconstructed with the rectus abdominis musculocutaneous free flap and 3 with the anterolateral thigh free flap. We reviewed survival rate, swallowing capacity, speech intelligibility, and volume reduction in flaps. Swallowing capacity and speech intelligibility were evaluated by visual analog scale scores (7 points) at 1 to 7 years after surgery, and changes in neotongue volume were examined by dividing volume into 4 stages. The 5-year disease-specific survival rate was 71%. Almost all patients were able to eat a soft diet and resume verbal communication. However, a sufficient volume of the reconstructed tongue was decreased over the course of time. Volume change was more definitive in the cases using the anterolateral thigh free flap than the rectus abdominis musculocutaneous free flap. Neotongue volume was also correlated with swallowing capacity and speech intelligibility. In total tongue reconstruction, wide and thick flaps such as the rectus abdominis musculocutaneous flap had better outcomes. Overcorrection with a sufficient flap volume is recommended for adequate oral intake owing to volume loss caused by radiation therapy, and functional muscle transfer should also be considered to prevent muscle atrophy. Lastly, static suspension procedures are emphasized to prevent airway aspiration for larynx preservation.

Effect of human adipose derived stem cells on scar formation and remodeling in a pig model: a pilot study.

BACKGROUND Adipose‐derived stem cells (ASCs) have positive effects in the wound healing process. OBJECTIVE To clarify whether ASCs positively mitigate scar formation in the wound remodeling process. MATERIALS AND METHODS Full‐thickness skin defects were created on the dorsal skin of Yorkshire pigs. After the defects were transformed into early scars, ASCs were injected, and the same amount of phosphate buffered saline (PBS) was injected in the control group. Clinical and histologic examinations were performed. RESULTS In the experimental group, the areas of scars were smaller than those of control groups. The color of scars was more similar to that of the surrounding normal tissue, and scar pliability was better. The number of mast cells decreased, and more‐mature collagen arrangement was noted. In the early period of scar remodeling, the expression of transforming growth factor beta (TGF‐&bgr;)3 and matrix metalloproteinase 1 (MMP1) was greater in the experimental group than in control group. In the late period, the level of alpha smooth muscle actin and tissue inhibitor of metalloproteinase 1 were dramatically less, although the level of MMP1 was lower in the experimental group than in control group. CONCLUSIONS Local injection of ASCs decreases scar size and provides better color quality and scar pliability. It decreases the activity of mast cells and inhibits the action of TGF‐&bgr; against fibroblasts and positively stimulates scar remodeling through greater expression of MMP molecules.

Early postoperative treatment of thyroidectomy scars using a fractional carbon dioxide laser

BACKGROUND Ablative carbon dioxide fractional laser systems (CO2 FS) have been effectively used to improve the appearance of scarring after surgical procedures, but an optimal treatment time has not been established. OBJECTIVE To evaluate the efficacy and safety of CO2 FS in early postoperative thyroidectomy scars. METHODS Twenty‐three Korean women with thyroidectomy scars were enrolled in this study. All patients underwent a single session of two passes of a CO2 FS with a pulse energy setting of 50 mJ and a density of 100 spots/cm2 2 to 3 weeks after surgery. RESULTS Mean Vancouver Scar Scale (VSS) scores were statistically significantly lower after laser treatment. Three months after CO2 FS treatment of thyroidectomy scarring, 12 of 23 participants showed clinical improvement of more than 51% from 2 to 3 weeks after surgery. The mean grade of clinical improvement based on independent clinical assessment was 2.6 ± 0.9. CONCLUSION Early postoperative CO2 FS treatment of thyroidectomy scars is effective and safe. The authors have indicated no significant interest with commercial supporters.

The effect of human placenta extract in a wound healing model.

Human placenta had been used on wound healing such as burns, chronic ulcers, and skin defects. Recently, human placenta has been widely used in the form of human placental extracts (HPE) by clinical field. However, it is unclear what the effect of HPE is on wound healing. We studied the effect and mechanism of HPE on wound healing.In this study, 10 mice (imprinting control region mice, 5 week old males, 30 g) were divided into an experimental group and a control group. An 8-mm diameter single full-thickness skin defect was made on the back by skin punch biopsy. At least 2.0 × 10−3 mL/30 g HPE was injected into the boundaries of the wound. Wound size measurements were taken by digital image every 3 days over 2 weeks. Hematoxylin and eosin (H and E), transforming growth factor beta (TGF-&bgr;), vascular endothelial growth factor (VEGF), and CD31+ immunohistochemical stains were performed on the 6th and 14th day.The experimental group showed acceleration in the decrease of wound size compared with the control group from the third day to the ninth day. TGF-&bgr; on the 6th day showed a statistically significant increase in the experimental group. VEGF on the 14th day showed a statistically significant increase in the experimental group. CD31+ was increased in the experimental group as wound healing progressed, but this increase was not statistically significant. The total number of vessels increased in the experimental group, but this was not statistically significant.We conclude that administering HPE directly to a wound margin promoted wound healing. This mechanism appears to be related to an increase in TGF-&bgr; in the early phase of wound healing and VEGF in the late phase.

Inferior gluteal artery perforator flap: a viable alternative for ischial pressure sores

The ischial area is by far the most common site for pressure sores in wheelchair-bound paraplegic patients, because most of the pressure of the body is exerted on this area in the seated position. Even after a series of successful pressure sore treatments, the site is very prone to relapse from the simplest everyday tasks. Therefore, it is crucial to preserve the main pedicle during primary surgery. Several surgical procedures, such as myocutaneous flap and perforator flap, have been introduced for the treatment of pressure sores. During a 4-year time period at our institute, we found favourable clinical results using the inferior gluteal artery perforator (IGAP) procedure for ischial sore treatment. A total of 23 patients (20 males and three females) received IGAP flap surgery in our hospital from January 2003 to January 2007. Surgery was performed on the same site again in 10 (43%) patients who had originally relapsed after undergoing the conventional method of pressure sore surgery. The average age of patients was 47.4 years (range 26-71 years). Most of the patients were paraplegic (16 cases, 70%) and others were either quadriplegic (four cases, 17%) or ambulatory (three cases, 13%). Based on hospital records and clinical photographs, we attempted to assess the feasibility and practicability of the IGAP flap procedure through comparative analysis of several parameters including the size of the defective area, treatment modalities, relapses, complications, and postoperative treatments. The average follow-up duration for 23 subjects was 25.4 months (range 5-42 months). All flaps survived without major complications. Partial flap necrosis developed in one case but secondary healing was achieved and the final outcome was not impaired. Most of the cases healed well during the follow-up period. Postoperative complications such as wound dehiscence and fistula developed in some subjects, but all healed well with a secondary treatment. A total of five cases relapsed after surgery due to tissue deficit and these were treated with bursectomy and muscle transposition flap to fill the dead space. We propose that the IGAP flap should be considered a viable alternative to other methods of ischial pressure sore surgery owing to its many advantages, which include the ability to preserve peripheral muscle tissue, the variability of flap designs, relatively good durability, and the low donor site morbidity rate.

The Use of Matriderm and Autologous Skin Graft in the Treatment of Full Thickness Skin Defects

Background For patients with full thickness skin defects, autologous Split-thickness skin grafts (STSG) are generally regarded as the mainstay of treatment. However, skin grafts have some limitations, including undesirable outcomes resulting from scars, poor elasticity, and limitations in joint movement due to contractures. In this study, we present outcomes of Matriderm grafts used for various skin tissue defects whether it improves on these drawbacks. Methods From January 2010 to March 2012, a retrospective review of patients who had undergone autologous STSG with Matriderm was performed. We assessed graft survival to evaluate the effectiveness of Matriderm. We also evaluated skin quality using a Cutometer, Corneometer, Tewameter, or Mexameter, approximately 12 months after surgery. Results A total of 31 patients underwent STSG with Matriderm during the study period. The success rate of skin grafting was 96.7%. The elasticity value of the portion on which Matriderm was applied was 0.765 (range, 0.635-0.800), the value of the trans-epidermal water loss (TEWL) was 10.0 (range, 8.15-11.00) g/hr/m2, and the humidification value was 24.0 (range, 15.5-30.0). The levels of erythema and melanin were 352.0 arbitrary unit (AU) (range, 299.25-402.75 AU) and 211.0 AU (range, 158.25-297.00 AU), respectively. When comparing the values of elasticity and TEWL of the skin treated with Matriderm to the values of the surrounding skin, there was no statistically significant difference between the groups. Conclusions The results of this study demonstrate that a dermal substitute (Matriderm) with STSG was adopted stably and with minimal complications. Furthermore, comparing Matriderm grafted skin to normal skin using Cutometer, Matriderm proved valuable in restoring skin elasticity and the skin barrier.

Gluteal artery perforator flap: a viable alternative for sacral radiation ulcer and osteoradionecrosis

Radiotherapy is a crucial part in the treatment of cancer; however, it may cause adverse effects to normal tissue such as radiation-induced ulcer and osteoradionecrosis. The few cases of conservative management that were reported had a limited value and unsatisfactory results. The most reliable method to treat sacral radiation ulcer and osteoradionecrosis is a wide excision of the affected tissue, followed by coverage with well-vascularised tissue. Musculocutaneous free flaps and local gluteus maximus musculocutaneous flaps have been used; however, there were many drawbacks such as dissection of recipient vessel in the previously radiated area and donor-site morbidity. During a 4-year time period at our institute, we found favourable clinical results using gluteal artery perforator procedure for radiation-induced ulcers and osteoradionecrosis of the sacral area. The 10 patients, who were treated with gluteal artery perforator flaps, had chronic non-healing radiation ulcers or bone exposure of the sacrum. Intra-operatively, massive debridement of bone and soft tissue was performed, while the well-vascularised skin with only a colour change was preserved. The flap was designed to include two or more perforators using Doppler flowmetry and the perforators were preserved with surrounding subcutaneous tissue during the flap elevation. The mean post-operative follow-up period was 25.7 months. As regards the surgery, there was one major complication (of partial flap loss) and three minor complications (of wound dehiscence). In the patient with partial flap loss due to infection and a floating flap, the contralateral superior gluteal artery perforator flap was used to treat complications. Other complications were conservatively treated and well healed. Gluteal perforator flaps are a valuable alternative in treating sacral radiation ulcers and osteoradionecrosis. Sufficient excision of devitalised tissue is a crucial procedure to achieve optimal results.

Enhanced chondrogenic responses of human articular chondrocytes onto silk fibroin/wool keratose scaffolds treated with microwave-induced argon plasma.

Silk fibroin (SF) is a natural, degradable, fibrous protein that is biocompatible, is easily processed, and possesses unique mechanical properties. Another natural material, wool keratose (WK), is a soluble derivative of wool keratin, containing amino acid sequences that induce cell adhesion. Here, we blended SF and WK to improve the poor electrospinability of WK and increase the adhesiveness of SF. We hypothesized that microwave-induced argon plasma treatment would improve chondrogenic cell growth and cartilage-specific extracellular matrix formation on a three-dimensional SF/WK scaffold. After argon plasma treatment, static water contact angle measurement revealed increased hydrophilicity of the SF/WK scaffold, and scanning electron microscopy showed that treated SF/WK scaffolds had deeper and more cylindrical pores than nontreated scaffolds. Attachment and proliferation of neonatal human knee articular chondrocytes on treated SF/WK scaffolds increased significantly, followed by increased glycosaminoglycan synthesis. Our results suggest that microwave-induced, plasma-treated SF/WK scaffolds have potential in cartilage tissue engineering.

Endothelial‐to‐mesenchymal transition induced by Wnt 3a in keloid pathogenesis

Endothelial‐to‐mesenchymal transition is a phenotypic conversion characterized by down‐regulation of vascular endothelial markers and the acquisition of a mesenchymal phenotype. We hypothesized that keloid fibroblasts are of endothelial origin and that endothelial‐to‐mesenchymal transition substantially contributes to collagen accumulation during the development and progression of keloids. Wingless protein (Wnt‐3a) protein expression was examined using immunohistochemistry in keloid tissues. Human dermal microvascular endothelial cells (HDMECs) were treated with Wnt‐3a. mRNA and protein expression of endothelial (vascular endothelial cadherin) and mesenchymal (vimentin, snail family transcription factor [slug], and α‐smooth muscle actin) cell markers were measured using real‐time RT‐PCR and immunocytochemistry, respectively. Additionally, coexpression of CD31 (cluster of differentiation 31), and endothelial cell marker, and vimentin in the vascular endothelium of keloid tissues was examined using immunofluorescence. Wnt‐3a overexpression was observed in human keloid tissues. Wnt‐3a treatment significantly reduced vascular endothelial cadherin mRNA expression and induced vimentin and slug mRNA expression in HDMECs. HDMECs became spindle‐shaped and exhibited reduced expression of CD31 and increased expression of vimentin, slug, and α‐smooth muscle actin. Moreover, coexpression of CD31 and vimentin was observed in the dermal vascular endothelium of keloid tissues from two patients with clinically active keloids. In conclusion, transient conversion of HDMECs to a mesenchymal phenotype may contribute to dermal fibrosis of keloid and hypertrophic scars.

Robot-Assisted Free Flap in Head and Neck Reconstruction

Background Robots have allowed head and neck surgeons to extirpate oropharyngeal tumors safely without the need for lip-split incision or mandibulotomy. Using robots in oropharyngeal reconstruction is new but essential for oropharyngeal defects that result from robotic tumor excision. We report our experience with robotic free-flap reconstruction of head and neck defects to exemplify the necessity for robotic reconstruction. Methods We investigated head and neck cancer patients who underwent ablation surgery and free-flap reconstruction by robot. Between July 1, 2011 and March 31, 2012, 5 cases were performed and patient demographics, location of tumor, pathologic stage, reconstruction methods, flap size, recipient vessel, necessary pedicle length, and operation time were investigated. Results Among five free-flap reconstructions, four were radial forearm free flaps and one was an anterolateral thigh free-flap. Four flaps used the superior thyroid artery and one flap used a facial artery as the recipient vessel. The average pedicle length was 8.8 cm. Flap insetting and microanastomosis were achieved using a specially manufactured robotic instrument. The total operation time was 1,041.0 minutes (range, 814 to 1,132 minutes), and complications including flap necrosis, hematoma, and wound dehiscence did not occur. Conclusions This study demonstrates the clinically applicable use of robots in oropharyngeal reconstruction, especially using a free flap. A robot can assist the operator in insetting the flap at a deep portion of the oropharynx without the need to perform a traditional mandibulotomy. Robot-assisted reconstruction may substitute for existing surgical methods and is accepted as the most up-to-date method.