Malcolm A. Lesavoy

Control of connective tissue metabolism by lasers: Recent developments and future prospects

Various laser modalities are currently in extensive use in dermatology and plastic surgery, particularly for treatment of vascular and pigmented lesions. A relatively new area of laser utilization involves the possible biologic effects of the lasers. In this overview, we are summarizing our recent studies, which indicate that lasers at specific wavelengths and energy densities modulate the connective tissue metabolism by skin fibroblasts both in vitro and in vivo. Specifically, the neodymium-yttrium-aluminum-garnet (Nd: YAG) laser was shown to selectively suppress collagen production both in fibroblast cultures and in normal skin in vivo, thus suggesting that this laser modality may be useful for the treatment of fibrotic conditions such as keloids and hypertrophic scars. Furthermore, two low-energy lasers, helium-neon (He-Ne) and gallium-arsenide (Ga-As), were shown to stimulate collagen production in human skin fibroblast cultures, suggesting that these lasers could be used for enhancement of wound healing processes. These experimental approaches illustrate the future possibilities for applying lasers for the modulation of various biologic functions of cells in tissues and attest to the potential role of lasers in the treatment of cutaneous disorders.

Effects of the Nd:YAG laser on DNA synthesis and collagen production in human skin fibroblast cultures

Human skin fibroblasts were subjected to treatment with a Neodymium:YAG laser at 1060 nm with varying levels of energy determined by a reproducible method of dosimetry. DNA synthesis in the cells was measured by the incorporation of [3H]thymidine, and collagen production was monitored by the synthesis of nondialyzable [3H]hydmxyprohne after incubation of cells with [3H]proline. Using energy levels equal to 1.7 × 103 l/cm2, a significant reduction in DNA synthesis was noted, while the cells remained viable as tested by the trypan blue exclusion lest. With energy levels higher or equal to 2.3 × 10 l/cm2, the suppression of DNA synthesis was accompanied by cell nonviability. The collagen production, when measured immediately following the treatment with 1.7 × 103 l/cm2, was markedly reduced, and similar effects were observed with higher energy levels. However, when the cells were tested for collagen production at 20 hours following laser treatment, there was a significant decrease in collagen production at energy levels as low as 1.1 × 103 l/cm2, a dose that did not affect DNA synthesis or cell viability. Thus, the results indicate that the Nd:YAG laser can selectively suppress collagen production without affecting cell proliferation. These observations suggest that laser treatment could potentially be used to reduce collagen deposition in conditions such as keloids and hyperlrophic scars.

Conservative treatment of cutis aplasia

Three cases of cutis aplasia are presented. The defects involved include full-thickness defects of scalp and cranium as well as full-thickness skin defects of the abdomen and thigh. All patients were treated conservatively with the use of Silvadene cream dressings. Healing was obtained in all patients.

Management of large scalp defects with local pedicle flaps.

Recent reports have emphasized free-flap reconstruction for large defects of the scalp and calvarium following resection of tumors, infection, or trauma. In most cases, however, a carefully planned local transposition or rotation flap may be equally effective, and the technical difficulties and donor-site problems associated with microsurgical tissue transfer are then avoided. We present 10 patients whose full-thickness scalp defects covered an average area of 241 cm2, or 27 percent, of the skull surface. Although this series included defects as large as 450 cm2, or 50 percent, of the skull surface area, each was easily managed with a local pedicle flap transfer. Four patients were reconstructed with parietal scalp transfer, four with an occipital scalp flap, and two with temporal scalp transfer. The technique and results are discussed.

The Transoral Treatment of Mandibular Fractures Using Noncompression Miniplates: A Prospective Study

A prospective study was performed to evaluate the efficacy of noncompression miniplates in the repair of mandible fractures treated at a large regional trauma center. The study included 54 cases of all types of adult mandible fractures with the exception of fractures of the condylar neck and ascending ramus. Cases were excluded in which preexisting infection was present. The technique consisted of a transoral approach followed by monocortical juxtaalveolar and subapical Osteosynthesis without long-term intermaxillary fixation. Overall, there were 7 complications associated with this technique (13%): 4 infections (7.4%), 1 malunion (1.9%), and 2 mental nerve paresthesias (3.7%). These results compare favorably with those reported in the literature and suggest that mandibular osteosynthesis using miniature malleable plates is a useful and effective method for the repair of selected mandible fractures.

Axillary breast tissue : clinical presentation and surgical treatment

Aberrant breast tissue is usually present along the milk line above or below the normal breast location. Occasionally, it is found in unusual locations, such as the axilla, scapula, thigh, and labia majora. Accessory axillary breast tissue is present in approximately 2% to 6% of women. Although this finding has been reported in a variety of clinical journals, such as Radiology and Human Pathology, it has received little attention in the plastic surgery literature. Axillary breast tissue, presenting as palpable thickenings in the axilla, can undergo monthly premenstrual changes, such as tenderness and swelling, difficulty with shoulder range of motion, and irritation from clothing. These symptoms may be exacerbated and become more apparent during puberty and pregnancy. In addition, it is cosmetically unsightful, and consequently, patients often desire surgery for improvement. We present a study of 28 patients who underwent surgical removal of their axillary breast tissue. From these successful reports, we recommend that axillary breast tissue should be surgically removed.

Muscle-Flap Coverage of Exposed Endoprostheses

A well-entrenched tenet in the orthopedic community is that dehiscent wounds overlying exposed endoprostheses should be treated by implant removal and delayed reconstruction. A new management protocol utilizing thorough soft-tissue debridement and myocutaneous or muscle-flap coverage was evaluated in four patients at the UCLA Medical Center who presented with exposed endoprostheses. These prostheses were placed for total-joint replacement or limb salvage surgery. All four prostheses and extremities were salvaged without the need for endoprosthesis removal or exchange, and no infections developed. The results suggest that late aseptic wound dehiscence with an exposed endoprosthesis need not be managed with prosthetic removal, arthrodesis, or amputation. This one-stage procedure avoided infection, allowed early mobilization, and shortened hospitalization.

Wound healing: biological effects of Nd:YAG laser on collagen metabolism in pig skin in comparison to thermal burn

Pig skin was treated with the Nd:YAG laser at 1,060 nm or electrocautery, at energy densities of 649 ± 20 J/cm2 and 612 J/cm2, respectively. Biopsies of treated areas and of normal skin were performed at 7, 14, and 60 days after treatment and processed for histology, electron microscopy and biochemical assays. Wound healing, as shown histologically, was similar in both treated groups. Depth of injury appeared to reach reticular dermis at day 7 in each treated group. However, thermal burn was more destructive of regular collagen, whereas the laser appeared to damage deep dermal blood vessels without destroying surrounding connective tissue. Biochemical assays revealed increased collagen production and increased collagenolytic activity 7 days after laser injury. However, by day 60, there was a reduction in total collagen content in laser treated skin below that of normal skin, which correlated with decreased collagen synthesis and unchanged collagenolytic activity. In burn specimens there was an initial decrease in total collagen content which reverted to normal by day 60. Active collagen degradation occurred at all 3 time points, but a marked increase in synthetic activity occurred as the burn scar was laid down. Laser treatment resulted in reduction of the amount of collagen below that in burn scarred or normal skin, suggesting that classical scar formation may be inhibited. These results indicate that the Nd:YAG laser may be useful for the treatment of keloids and hypertrophic scars.

Total abdominal wall reconstruction in the prune belly syndrome.

A total of 6 boys with the prune belly syndrome underwent total abdominal wall reconstruction by a technique that permits simultaneous bilateral orchiopexy and/or urinary tract reconstruction. Until now, the psychosocial implications of the abdominal wall disfigurement caused by this syndrome have been ignored. This procedure provides an excellent cosmetic result that, in turn, promotes psychological health and a positive body image in these children.

Umbilicus preservation with total abdominal wall reconstruction in prune-belly syndrome

A technique to preserve the umbilicus in abdominal wall reconstruction for prune-belly syndrome is presented. Our technique has been utilized in 5 cases with success.