An in vivo histopathological comparison of single and double pulsed modes of a fractionated CO(2) laser.

INTRODUCTION: Studies examining the histopathological changes that occur in human skin following fractional laser treatment have been performed mainly in animals or abdominal tissue prior to abdominoplasty. This study looks at the effect of double pulse fractional CO(2) laser compared to single pulse treatments to assess differences in tissue injury in the face and abdomen. METHODS: Twelve healthy subjects randomized into two groups, had two 1 cm(2) areas (infraumbilical and forehead) treated with the fractional CO(2) laser (Deep Fx, Lumenis). Settings used were 15 mJ double pulse, and 30 mJ single pulse, 300 Hz, 10% density and compared to the historic control of 15 patients treated at 15 mJ single pulse [Bailey et al. (2011), Lasers Surg Med 43: 99-107]. Treated sites were biopsied and analyzed with H&E and TUNEL staining to measure width and depth of the microthermal zones (MTZ) of ablation. RESULTS: When comparing 15 mJ double pulse to single pulse there were significant differences both in depth (abdominal skin, P = 0.002 and facial skin, P = 0.001) and width (facial skin, P = 0.0002) of MTZ. When comparing double pulsing at 15 mJ with single pulsing at 30 mJ there were significant differences between MTZ depths in the abdomen (P < 0.01) but not in either the MTZ depth (P = 0.69) or the width in the face (P = 0.502). DISCUSSION: This study demonstrates the differences between histopathological laser injury patterns in the face compared to the abdomen when single pulsing is used. It also demonstrates that double pulsing at 15 mJ is statistically similar to single pulsing at 30 mJ in the face. We think this could have ramifications for clinical practice where by double pulsing at lower energies may result in better clinical outcomes than increasing energies or using multiple passes at single pulse. Clinical studies needs to be performed to investigate this further.

Micro-island damage with a nonablative 1540-nm Er:Glass fractional laser device in human skin.

BACKGROUND AND OBJECTIVES: Fractional photothermolysis produces micro-islands of thermal injury to the skin while preserving areas among treated tissue sites in order to promote wound healing. Histological changes associated with single and multiple passes of the 1540-nm Er:Glass fractional laser were examined using in vivo human skin. METHODS AND MATERIALS: Panni of five abdominoplasty patients were treated intraoperatively with a Fractional Lux1540 erbium glass laser system at various laser parameters, with single and multiple passes. Biopsies were removed and examined using standard histological stains. RESULTS: Deep coagulated columns of collagen separated by regions of unaffected tissue were observed at variable fluence parameters. A direct correlation between the depth of penetration of the coagulated microcolumns and increasing energies was observed. Micro-islands of coagulation were approximately 250 microm in diameter and separated by approximately 800 microm of unaffected tissue. With multiple passes, significantly more disruption of the dermal-epidermal junction (DEJ) occurred at higher fluences. In contrast to the controlled fractional columns observed with single-pass treatments, nonuniform coagulated columns were distributed randomly throughout the tissue when instituting multiple passes over the same treatment region. CONCLUSION: Micro-islands of thermal damage were observed at variable energy parameters. Pathological changes within the skin were clearly dependent on amount of energy and number of passes of the laser treatment. Significantly more superficial damage, accompanied by disruption of the DEJ was observed with multiple passes when compared with single pass at similar fluences. However, with multiple passes, depth of thermal injury did not increase with increasing energies but did disrupt the micro-island array observed with single-pass fractional treatments.

Efficacy of lidocaine for pain control in subcutaneous infiltration during liposuction.

BACKGROUND: Liposuction remains the most commonly performed aesthetic surgical procedure in the United States. Preoperative infiltration of the subcutaneous tissues with a wetting solution has become standard. These solutions typically contain some amount of lidocaine for pain control. High doses of lidocaine have been demonstrated to be safe, but large amounts of this cardioactive agent during elective cosmetic procedures may be unnecessary. OBJECTIVE: A study was designed to examine the effects of wetting solutions with lower concentrations of lidocaine on perioperative pain. METHODS: Seventeen patients were prospectively randomized to subcutaneous infiltration with one of 3 different lidocaine concentrations: 10 mg/kg, 20 mg/kg, or 30 mg/kg. Intra- and postoperative lidocaine and monoethylglycinexylidide (MEGX) plasma concentrations were measured and the total intraoperative inhalation gas requirements and minimum alveolar concentrations were recorded. Postoperative pain medication requirements were recorded and morphine equivalents were calculated. Patient pain level was subjectively assessed by using a visual analog pain scale. RESULTS: There was no difference in the intraoperative lidocaine or MEGX concentrations between any of the 3 groups. There was also no statistical difference between the 3 groups when comparing intraoperative inhalational gas requirement, postoperative morphine equivalence requirements, or subjective pain using the visual analog scale. CONCLUSIONS: Decreasing concentrations of lidocaine in infiltrative wetting solutions did not significantly affect intraoperative anesthesia requirements or postoperative pain with liposuction. Lower concentrations of lidocaine can effectively be used, use of any lidocaine may be unnecessary. Future investigations may examine whether total elimination of lidocaine yields similar results in terms of anesthesia requirements and postoperative pain.

TUNEL assay for histopathologic evaluation of irreversible chromosomal damage following nonablative fractional photothermolysis.

BACKGROUND: Fractional photothermolysis is extremely popular in skin rejuvenation and remodeling procedures. However, the extent of thermal cellular injury beyond the borders of the coagulated microcolumns produced with fractional phototherapy is undefined. METHODS: Six abdominoplasty patients were pretreated with the Lux1540 Fractional Erbium device (Palomar, Inc., Burlington, Mass.) at various clinical laser settings. After tissue excision, the panni were immediately biopsied. Biopsy specimens were fixed in formalin, embedded in paraffin, sectioned, and evaluated with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) procedure for cellular necrosis/apoptosis. Tissue was sectioned horizontally and longitudinally to help define the depth and distribution of the microcolumns of injury in a three-dimensional plane. RESULTS: The extent of cellular necrosis/apoptosis at variable depths within the epidermis and dermis was demonstrated successfully with the TUNEL technique. After the Lux1540 treatment, TUNEL-positive nuclei were identified in a vertically oriented fashion that extended from the epidermis into the papillary and reticular dermis, highlighting the areas of injury. The TUNEL-positive nuclei defined lesions that were approximately 175 to 225 microm in diameter and penetrated to variable depths (200 to 900 microm), depending on the fluence used for treatment (18 to 100 mJ). CONCLUSIONS: TUNEL immunofluorescent labeling provided an accurate assessment of cellular damage within and surrounding the microthermal zones of coagulated collagen with respect to column depth and width. Because of its specificity, the TUNEL assay can be a useful adjunct to other histologic stains used to characterize cellular damage and matrix denaturation in skin treated with any fractional ablative or nonablative laser device.

The science of mesotherapy: chemical anarchy.

The author stresses that to date, the effects of mesotherapy have not been scientifically evaluated. Currently, there is no standardization of dosage and no protocol or treatment algorithm to enable prediction of how much tissue or fat will be "dissolved" with a specific solution in a defined quantity, and injected at a specified subcutaneous tissue depth.

Oral nutritional supplementation accelerates skin wound healing: a randomized, placebo-controlled, double-arm, crossover study.

Nutritional therapy is critical for wound healing in people with severe malnutrition or specific metabolic deficiencies. Medical claims from manufacturers of many oral supplements are marketed to surgical patients for decreasing edema, bruising, and discomfort. The effect of supplementing nutrients on soft-tissue wound healing in otherwise normal, healthy adults is an area of clinical importance, but little information is available. Proteolytic enzymes have been reported to moderate the inflammatory cycle and may up-regulate the healing process. The goal of this study was to perform a clinical trial in normal, healthy adults that examined the effects of an oral nutritional supplement (InflammEnz, Enzymes, Inc., Parkville, Mo.) on soft-tissue healing times. Twenty-six normal, healthy volunteers were recruited into a randomized, crossover, placebo-controlled, clinical trial consisting of two phases, each lasting 21 days. In phase I, subjects were subjected to a 3-mm forearm skin biopsy and randomly received a placebo or oral supplement (four capsules per day for 7 days). After a 2-week washout period, a second biopsy was performed to start phase II, with each subject receiving the respective placebo or supplement capsules. Digital photographs were taken during wound healing in both phases and analyzed for wound areas (in square millimeters) and perimeters (in millimeters). Twenty-two subjects completed the clinical trial. On the basis of wound surface areas, 17 subjects had improved wound healing and five subjects did not respond or responded only slightly to the supplement treatment. The mean +/- SD healing time of the subjects responding to supplement-treated wounds was 15 +/- 2.2 days, compared with 18 +/- 2.5 days for the placebo group. The 17 percent acceleration of wound-healing time was significant (p < 0.005). In subjects responding to oral supplements, less redness in the wounds was observed that may have been associated with less inflammation. The authors' results demonstrate that InflammEnz oral supplementation accelerated soft-tissue wound healing in 77 percent of normal, healthy subjects studied. The authors' study validates observations made that this supplement modulates the wound-healing process and suggests that many patients with minor soft-tissue wounds may benefit from treatment.

Effect of low-level laser therapy on abdominal adipocytes before lipoplasty procedures.

Low-level laser therapy is a new subspecialty for the medical application of lasers that provides therapeutic rather than surgical outcomes for many medical indications. Recently, low-level laser therapy was reported to "liquefy" or release stored fat in adipocytes by the opening of specialized yet not identified cell membrane-associated pores after a brief treatment. Currently, low-level laser therapy is a U.S. Food and Drug Administration-approved technology for improving pain alleviation. To explore these data further, a series of in vitro studies on human preadipocytes and institutional animal care and use committee-approved protocols in a porcine Yucatan model and an institutional review board-approved clinical study were performed. Using a 635-nm low-level laser of 1.0 J/cm supplied to the authors by the vendor, these studies were designed to determine whether alteration in adipocyte structure or function was modulated after low-level laser therapy. Cultured human preadipocytes after 60 minutes of laser therapy did not change appearance compared with nonirradiated control cells. In the porcine model, low-level laser therapy (30 minutes) was compared with traditional lipoplasty (suction-assisted lipoplasty) and ultrasound-assisted lipoplasty. From histologic and scanning electron microscopic evaluations of the lipoaspirates, no differences were observed between low-level laser therapy-derived and suction-assisted lipoplasty-derived specimens. Using exposure times of 0, 15, 30, and 60 minutes in the presence or absence of superwet wetting solution and in the absence of lipoplasty, total energy values of 0.9 mW were delivered to tissue samples at three increasing depths from each experimental site. No histologic tissue changes or specifically in adipocyte structure were observed at any depth with the longest low-level laser therapy (60 minutes with superwet fluid). Three subjects undergoing large-volume lipoplasty were exposed to superwet wetting fluid infiltration 14 minutes before and 12 minutes after, according to vendor instructions. Tissue samples from infiltrated areas were collected before suction-assisted lipoplasty and lipoaspirates from suction-assisted lipoplasty. No consistent observations of adipocyte disruptions were observed in the histologic or scanning electron microscopy photographs. These data do not support the belief that low-level laser therapy treatment before lipoplasty procedures disrupts tissue adipocyte structure.