Shyi-Gen Chen

Reconstruction of burn scar of the upper extremities with artificial skin.

The management of upper‐extremity burn contractures is a major challenge for plastic surgeons. After approval by the Food and Drug Administration, artificial skin (Integra) has been available in Taiwan since 1997. From January of 1997 to July of 1999, the authors applied artificial skin to 13 severely burned patients for the reconstruction of their upper extremities, resulting in an increased range of motion in the upper‐extremityjoints and improved skin quality. An additional benefit was the rapid reepithelialization of the donor sites. There were no complications of infection throughout the therapeutic course, and the overall results were satisfactory. During the 2‐year study, scar condition was monitored between 8 and 24 months, and a good appearance and pliable skin were obtained according to the Vancouver Scar Scale. According to this evaluation of Oriental skin turgor, normal pigmentation was restored about 6 months after the resurfacing procedure. For patients with severe burns in whom there is insufficient available skin for a full‐thickness skin graft or another appropriate flap for scar revision, Integra is an alternative. The two major concerns in dealing with artificial skin are (1) a 10‐ to 14‐day waiting period for maturation of the neo‐dermis, necessitating a two‐stage operation, and (2) prevention of infection with antibiotics and meticulous wound care. (Plast. Reconstr. Surg. 108: 378, 2001.)

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.

The distally based lesser saphenous venofasciocutaneous flap for ankle and heel reconstruction.

&NA; Finding an appropriate soft‐tissue grafting material to close a wound located over the ankle and heel can be a difficult task. The distally based lesser saphenous venofasciocutaneous flap mobilized from the posterior aspect of the upper leg, used as an island pedicle skin flap, can be useful for this purpose. The vascular supply to the flap is derived from the retrograde perfusion of the accompanying arteries of the lesser saphenous vein. These arteries descend along both sides of the lesser saphenous vein to the distal third of the leg, either terminating or anastomosing with the septocutaneous perforators of the peroneal artery. Between February of 1999 and March of 2001, four variants of this flap were applied in 21 individuals, including 11 fasciocutaneous, five fascial, three sensory, and two fasciomyocutaneous flaps. Skin defects among all patients were combined with bone, joint, and/or tendon exposure. The authors found that the flap was reliable and technically simple to design and execute. This one‐stage procedure not only preserves the major arteries and the sural nerve of the injured leg, but it also has proved valuable for covering a weight‐bearing heel and filling a deep defect, because it potentially provides protective sensation and a well‐vascularized muscle fragment. When conventional local flaps are inadequate, this flap should be considered for its reliability and low associated morbidity. (Plast. Reconstr. Surg. 110: 1664, 2002.)

The comparison of early fluid therapy in extensive flame burns between inhalation and noninhalation injuries.

Over the last half century, advances in treatment have changed the principal cause of death in burn patients from burn shock and wound sepsis to pulmonary sepsis, of which inhalation injury has always played a key role in morbidity and mortality. Even though Navar et al., Am. J. Surg. 1985;150:716-720 have noted that patients with inhalation injury had a mean fluid requirement of 5.8 ml/kg/% burn to achieve resuscitation from early burn shock, while patients without inhalation injury required only a mean fluid of 4.0 ml/kg/% burn, to achieve successful resuscitation in inhalation injured patients with minimum but adequate fluid has always been a challenge. To further define the difference of early fluid therapy between inhalation and noninhalation in extensively burned patients, a retrospective analysis was carried out in the Tri-Service General Hospital. Sixty-two flame burned patients (aged from 16 to 81 years-old with a mean age of 33.2+/-15.1 years: with burn size ranging from 30% to 98% TBSA with a mean burn size of 60.5+/-22.7%; 26 with inhalation injury; noninhalation 36) were reviewed during a 5-year period. The Parkland formula is the initial choice of fluid regimen with 4 ml/kg/% burn and the amount of replacement is monitored by urine output and is titrated to maintain urine output between 0.5 and 1.0 ml/kg/h. The mean amounts of fluid requirements of both inhalation and noninhalation burned patients were 3.1 +/- 1.0 and 2.3+/-0.8 ml/kg/% burn respectively (p < 0.05). Our study showed less fluid requirement for both inhalation and noninhalation injured patients in comparison with the Navar study and Parkland predictions in the first 24 h postburn. Furthermore, the inhalation injured patients definitely required volumes of fluid in excess of those required in noninhalation injured cases.

The management of white phosphorus burns

Phosphorus burns are a rarely encountered chemical burn, typically occurring in battle, industrial accidents, or from fireworks. Death may result even with minimal burn areas. Early recognition of affected areas and adequate resuscitation is crucial. Amongst our 2765 admissions between 1984 and 1998, 326 patients had chemical burns. Seven admissions were the result of phosphorus burns. Our treatment protocol comprises 1% copper sulfate solution for neutralization and identification of phosphorus particles, copious normal saline irrigation, keeping wounds moist with saline-soaked thick pads even during transportation, prompt debridement of affected areas, porcine skin coverage or skin grafts for acute wound management, as well as intensive monitoring of electrolytes and cardiac function in our burns center. Intravenous calcium gluconate is mandatory for correction of hypocalcemia. Of the seven, one patient died from inhalation injury and the others were scheduled for sequential surgical procedures for functional and cosmetic recovery. Cooling affected areas with tap water or normal saline, prompt removal of phosphorus particles with mechanical debridement, intensive monitoring, and maintenance of electrolyte balance are critical steps in initial management. Fluid resuscitation can be adjusted according to urine output. Early excision and skin autografts summarize our phosphorus burn treatment protocol.

Do antibacterial-coated sutures reduce wound infection in head and neck cancer reconstruction?

BACKGROUND Surgical wound infection is a common complication, which increases the hospital stay and costs after surgery for head and neck cancer. In this study, we evaluated the effect of Triclosan-coated sutures on surgical wounds and analyzed the risk factors for wound infections in head and neck cancer surgery. PATIENTS AND METHODS From January 2007 to December 2009, 253 consecutive patients underwent wide excision of a head or neck cancer and reconstructive procedures. All patient data were collected prospectively. Of these, 241 patients were included in this study, divided into two groups. The Triclosan group contained 112 patients, whose surgical wounds were closed with Triclosan-coated sutures (Vicryl Plus). The control group included the remaining 129 patients, whose surgical wounds were closed with conventional Vicryl sutures. We conducted a retrospective, multivariate analysis to determine independent risk factors for the cervical wound infection. RESULTS The cervical wound infection rate was 14.9% (17/112) in the Triclosan group and 14.7% (19/129) in the control group, and these rates were not significantly different. Tumour stage and delayed intra-oral flap healing were independent risk factors for cervical wound infection. CONCLUSIONS In this preliminary study, Triclosan-coated Vicryl sutures did not reduce the infection rate of cervical wounds after head or neck cancer surgery. The effectiveness of this suture material in head and neck cancer surgery should be considered with caution.

Assessment of the perforators of anterolateral thigh flaps using 64-section multidetector computed tomographic angiography in head and neck cancer reconstruction

BACKGROUND The anterolateral thigh (ALT) flap is a frequent choice for free flap transfer in head and neck cancer reconstruction because of its versatility. Preoperative mapping of the perforator pedicles of an ALT flap is still a challenge because of variations in vasculature. Although computed tomographic angiography (CTA) is used increasingly to evaluate the peripheral vasculature, the use of this method for evaluating the perforators of an ALT flap has not been described in detail. METHODS From September 2008 to March 2009, 32 patients underwent preoperative CTA before free ALT flap transfer for head and neck cancer reconstruction. The perforators were marked on a 64-section multidetector CT image for each patient. The preoperatively mapped perforators were compared with the actual intraoperative findings. Flap success rates and associated morbidity and complications were recorded. RESULTS Preoperative CTA identified major variations in perforators. Eighty-four were found by preoperative CTA; 64 of these were mapped to be explored during the operation, and 13 additional perforators were identified during surgery. The accuracy rate of identifying the branching origin of the ALT perforators was 98% (63/64). All of the ALT flaps survived except for one with necrosis (survival rate 97%). There was no donor site morbidity. CONCLUSIONS Preoperative mapping of perforators by CTA proved valuable in free ALT flap transfer and shortened the operation time significantly. This modality provides useful information for head and neck cancer reconstruction in difficult cases, especially in patients with large or through-and-through defects that might need multiple perforators in flap design.

The boomerang flap in managing injuries of the dorsum of the distal phalanx.

Finding an appropriate soft-tissue grafting material to close a wound located over the dorsum of a finger, especially the distal phalanx, can be a difficult task. The boomerang flap mobilized from the dorsum of the proximal phalanx of an adjacent digit can be useful when applied as an island pedicle skin flap. The vascular supply to the skin flap is derived from the retrograde perfusion of the dorsal digital artery. Mobilization and lengthening of the vascular pedicle are achieved by dividing the distal end of the dorsal metacarpal artery at the bifurcation and incorporating two adjacent dorsal digital arteries into one. The boomerang flap was used in seven individuals with injuries involving the dorsal aspect of the distal phalanx over the past year. Skin defects in all patients were combined with bone, joint, or tendon exposure. The authors found that the flap was reliable and technically simple to design and execute. This one-step procedure preserves the proper palmar digital artery to the fingertip and has proven valuable for the coverage of wide and distal defects because it has the advantages of an extended skin paddle and a lengthened vascular pedicle. When conventional local flaps are inadequate, the boomerang flap should be considered for its reliability and low associated morbidity.

Computed tomography angiography imaging for the chimeric anterolateral thigh flap in reconstruction of full thickness buccal defect

Background:  Microvascular free flap transplantation is the current most common choice for reconstruction of difficult through‐and‐through buccal defect after cancer extirpation. The chimeric anterolateral thigh (ALT) flap is an ideal flap to cover this full thickness defect, but variation in the location of perforators is a major concern. Herein, we introduce computed tomographic angiography (CTA)‐guided mathematical perforators mapping for chimeric ALT flap design and harvest.

Skin injury in the operating room

Skin injury occurring in the operating room may occur as a result of electrical current, thermal injury, chemical irritation and mechanical stress. Between 1 December 1996 and 28 February 1997, 19 cases of skin injury from a total of 3657 operations were noted in our hospital. These injuries tend to be ignored because of their early spontaneous healing. We suggest that medical staff should pay more attention to this complication and prevent it from occurring.