Thermal Injury Zones Research Articles

Evaluating the Efficacy of Platelet Rich Plasma and 1550 nm Fractional Laser in Combination and Alone for the Management of Androgenetic Alopecia.

Androgenetic alopecia (AGA) in men and women is the most common cause of hair loss. Affected individuals may experience psychological distress and social withdrawal. Current treatment options for AGA, such as minoxidil and finasteride, vary in efficacy and have side effects. Platelet-rich plasma (PRP) and photobiomodulation are among treatment options that have gained popularity in recent years. While less is known about the effectiveness of fractional lasers for combating hair loss, research suggests that by creating microscopic thermal injury zones, fractional lasers may cause an increase in hair growth from a wound healing process. In this study, we evaluated the efficacy and safety of PRP and 1550 nm fractional erbium-glass laser as monotherapy or combination treatment for AGA in 60 patients. All patients experienced improvement in AGA, but patients treated with the combination therapy had greater improvement in hair density. Overall, PRP and 1550 nm in combination or alone are good treatment choices for AGA, with no side effects. J Drugs Dermatol. 2022;21(11):1166-1169. doi:10.36849/JDD.6750.

Characterization of Cold and Heat Tolerance of Bactrocera tau (Walker).

Simple SummaryInsects are often stressed by adverse factors in their natural environment. Temperature is a crucial driver of insect activity, adaptability, and distribution, and therefore, it greatly impacts the invasive success of alien pests. Bactrocera tau (Walker) is an invasive polyphagous herbivore of vegetables and fruits, now a pest of global importance. This study provides useful information about B. tau’s cold- and heat tolerance to extremely low and high temperatures. Its different life stages (i.e., egg, larvae, pupae, and adult) had high survival rates under adverse temperatures spanning −5 to 0 °C and 39 to 42 °C. These findings suggest that B. tau possesses a wide temperature threshold range for survival, which likely contributes to its better establishment and expansion in new regions. Meanwhile, fitted curves were used to quantify B. tau’s tolerance potential as a function of both stress intensity (heat or cold) and exposure duration. The information generated in this study will contribute to our understanding of thermal tolerance in B. tau and could also provide insights for devising phytosanitary control approaches.Bactrocera tau (Walker) (Diptera: Tephritidae) is a serious, economically important invasive pest that has spread and been established in many regions worldwide. Temperature is a crucial abiotic factor governing insect activity, fitness, and geographical distribution. Yet, surprisingly, the tolerance of B. tau to extreme cold and heat stress remains unclear. Here, we measured the supercooling point (SCP) of different life stages of B. tau. Further, several life stages of B. tau (egg, 1st, 2nd, and 3rd instar larvae, 1-day-old pupae, and 3-day-old adult) were subjected to six low temperatures (−9, −7, −5, −3, −1, and 0 °C) and six high temperatures (39, 40, 41, 42, 43, and 44 °C) for various durations (0.5, 1.0, 2.0, and 4.0 h), and three-way survival–time–temperature relationships were investigated. We found that the SCPs differed significantly among different life stages of B. tau, being the lowest for SCP of eggs, at −25.82 ± 0.51 °C. There was no significant effect of sex on the mean SCPs of B. tau adults, except for 45- to 50-day-old flies. In addition, an interaction effect was uncovered between tested temperatures and exposure duration upon B. tau mortality at different life stages. Eggs exhibited the strongest cold tolerance, yet the weakest heat tolerance. The 3rd instar larvae were the most heat- and cold tolerant among larval stages, followed by the 2nd and 1st instar larvae. The upper limit of the chill injury zone (ULCIZ) for 3-day-old adult and 1-day-old pupae was −2.51 °C and −2.50 °C, respectively, while their corresponding lower limit of thermal injury zone (LLTIZ) was 39.39 °C and 38.29 °C. This paper presents valuable data to provide an integrated knowledge for understanding the cold and heat tolerance potential of B. tau and ensure the proper implementation of post-harvest phytosanitary protocols for this pest’s disinfestation.

Evaluation of skin tissue effects from treatment with a novel hand-held plasma energy device.

Plasma IQ™, the first FDA-cleared hand-held plasma energy device, is indicated for removal and destruction of skin lesions and coagulation of tissue. Treatment involves use of an electrostatic plasma spark to heat the skin and create discrete microthermal wounds. Microthermal wounds on pre-auricular and upper eyelid skin from two individual subjects were created using multiple treatment parameters to assess the impacts of power, pulse duration and needle electrode type on wound depth, width and thermal spread, and analyzed using histology to characterize treatment effects. Device power had a statistically significant impact on upper eyelid skin microthermal wound depth and width (2-sided t-test p<0.0001 for both) but not on thermal spread (p=0.1171). No meaningful differences in wound width, depth, or thermal spread were observed based on pulse duration or electrode type. All microthermal wounds demonstrated dual zones of tissue injury and extended to the superficial reticular dermis. Treatment with the Plasma IQ™ device creates focal microthermal wounds of reproducible depth and width that are comprised of dual thermal injury zones similar to other plasma energy skin rejuvenation devices. Device power is the most important factor determining microthermal wound depth and width.

Assessing the Outcomes of Focused Heating of the Skin by a Long-Pulsed 1064 nm Laser with an Integrated Scanner, Infrared Thermal Guidance, and Optical Coherence Tomography.

The skin on the forearm and back of two consenting volunteers was marked and anesthetized with lidocaine with epinephrine. The parameters of a scanner-equipped LP 1064 nm Nd:YAG laser were adjusted to achieve an epidermal/superficial dermal heating of between 50°C and 60°C over a specified time course. Experimental single treatments examined various adjusted parameters including, fluence, pulse overlap, pulse duration, scan size, and pulse rate. A FLIR camera was used to record skin temperature. Outcome measures included skin temperature, post-treatment appearance, and OCT assessment of skin and vascular damage. The clinical response of each treatment was followed daily for 4 weeks. Optimal protocols initially raised the skin temperature to between 55°C and 60°C, which was carefully maintained using subsequent laser passes over a 60-second time course. Immediately post laser, clinical responses included erythema, edema, and blistering. Immediate OCT revealed increased vascularity with intact, dilated blood vessels. Prolonged exposure above 60°C resulted in sub-epidermal blistering and an absence of blood flow in the treatment area with prolonged healing. The LP 1064 nm laser can be used to achieve heat-related tissue injury, though the narrow parameters necessary for the desired endpoint require the assistance of IR thermal regulation to avoid unacceptable outcomes. The use of the laser scanner ensures precise energy delivery over a defined treatment area. Future studies might explore this as a selective hyperthermic method for the treatment of non-melanoma skin cancer. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

A new treatment protocol of microfocused ultrasound for lower eyelid fat bulging

Background Microfocused ultrasound (MFU) causes tissue tightening by producing thermal injury zones and is used to treat various age-related changes including lower eyelid fat bulging. Objective To investigate the efficacy of a new treatment protocol of MFU for lower eyelid fat bulging. Methods and materials We reviewed the medical records of all patients who began MFU for lower eyelid fat bulging from March 2017 to September 2018. MFU was performed in two steps to tighten the lower eyelid dermis and orbital septum. Data on age, sex, bulging severity, and the number of treatment sessions were obtained. Associations of these variables with treatment response were determined through an ordinal logistic regression analysis. Results Among 191 enrolled patients, 119 (62.3%) and 47 (24.6%) achieved fair and good responses, respectively. In the multivariable analysis, multiple treatment sessions (odds ratio (OR) 6.618; 95% confidence interval (CI) 3.242–13.513; p < .001), moderate bulging (OR 4.328; 95% CI 1.755–10.671; p = .001), and severe bulging (OR 7.570; 95% CI 2.537–22.585; p < .001) were associated with greater treatment response. There were no serious adverse events. Conclusions The new treatment protocol of MFU is an effective and safe strategy for lower eyelid fat bulging.

Structural transformations of thermal burn wounds in rats under the influence of Semax and Selank neuropeptides

The morphological features of the skin of rats under the stress exposure, such as burn injury and against the background of the correction by the drugs of the peptide structure, have been studied.The aim of the study was to investigate the regulatory effect of the neuropeptide drugs Semax (Met-Glu-His-Phe-Pro-Gly-Pro) and Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) under the conditions of thermal burn exposure.Materials and methods. The object of the study was integumentary tissues (skin, subcutaneous tissue) of laboratory non-linear male rats (n = 36) excised from the thermal injury zone. A thermal burn of the skin had been caused by the application of a copper object in the interscapular in the interscapular dorsal area. Starting from the first day after the injury, neuropeptide drugs Semax (Met-Glu-His-Phe-ProGly-Pro) and Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) had been administered intraperitoneally at the doses of 100 μg/kg daily during the entire period of the experiment. To assess the condition of the skin tissues, histological sections 5–6 μm thick were prepareв, stained afterwards with hematoxylin and eosin. The consistency of the systemic effect of the neuropeptide drugs was estimated by a change in some indicators of the immune system.Results. The thermal exposure led to the development of significant degenerative and dystrophic changes in the skin. The recovery of the burn wounds on rats’ skins proceeded according to the type of the delayed partial reparative regeneration, accompanied by destructive phenomena and the formation of the scar tissue.Under the influence of the drugs based on the regulatory peptides of Semax (Met-Glu-His-Phe-Pro-Gly-Pro) and Selank (Thr-Lys-Pro-Arg-ProGly-Pro), the recovery of burn wounds in rats proceeded more intensively, compared with the animals from the group without any correction. This fact was confirmed by the earlier signs of the beginning of the reparative skin regeneration: the restriction of destructive processes within the epidermis and dermis, the absence of purulent-necrotic complications, the initial phases of granulation and epithelization, an early scab rejection and a partial closure of the defect.Conclusion. The use of the neuropeptide drugs Semax and Selank as systemic remedies for the correction of wound skin defects in experimental animals proves their polypotent effectiveness, expands the therapeutic possibilities and opens up new prospects for their use.

Preliminary Evaluation of Thulium Doped Fiber Laser in Pig Model of Liver Surgery.

Partial liver resection is a treatment of choice for liver tumors; the range of parenchyma excision varies from a small part of the tissue surrounding the neoplasm up to 70% of the organ. One of the major concerns during liver resection is blood loss. Thulium lasers which are characterized by the length of emission wave corresponding to a peak absorption of water create a new possibility of cutting tissues efficiently with minimal thermal damage and concurrently providing a good hemostasis control. The aim of our study was to evaluate an impact of liver transection with thulium doped fiber laser on an intraoperative bleeding and histopathological changes during postoperative period in swine model. Ten animals were subjected to open surgery partial liver resection and an incision of liver tissue with an all-fiber, diode-pumped, and continuous-wave Tm3+-doped fiber laser emitting 37.4 W of output power at ~1.94 μm wavelength. The macroscopic and histopathological evaluation was performed intraoperatively as well as 7 and 14 days after surgery. Macroscopically almost no bleeding was observed during surgery and no signs of bleeding were stated after 7 and 14 days. Histopathological analysis of the transection margin revealed a thermal damage area ranging in depth from 620.23 ± 23.82 μm on the day of surgery to 1817.70 ± 211.98 μm after 7 days. In the samples taken intraoperatively and after 7 days a superficial zone of carbonization was visibly separated from the deeper changes. After 14 days one 765.35 μm deep zone characterized by a granulation was present. In conclusion, thulium doped fiber laser is efficacious in cutting with a narrow zone of thermal injury and provides a good hemostasis during liver transection, thus being a potential tool for oncotic liver surgery.

Fractional Laser As Laser Assisted Drug Delivery of Triamcinolone Acetonide in Keloid

Background: Keloid is benign hyperplasia of dermal collagen which may or may not be preceded by injury in susceptible person. Keloids are refractory to treatment most of the times. Intralesional corticosteroid, topical retinoic acid, topical imiquimod cream, surgery, cryotherapy, laser, and silicon sheeting are mainly used for treatment. Fractional ablative laser is a new laser treatment modality that create numerous microscopic thermal injury zone controlled width, depth, and density that are surrounded by a reservoir of spared epidermal and dermal tissue, allowing of rapid repair of laser-induced thermal injury. Multiple studies demonstrate that laser pretreatment of the skin can increase the permeability and depth of penetration of topical drug molecules. Main observations: A boy, 12 years, scar that arise after burn scar 14 months ago. Scar was felt bigger and thickening also itching. Patient was diagnosed keloid and had been treated with same-session ablative fractional laser and topical triamcinolone acetonide after therapy. Patient had been treated 5 sessions with 3 weeks of interval. Successful of treatment was measured with reduction of keloid size and vancouver scar scale (VSS). Conclusions: Laser assisted drug delivery is an envolving technology with potentially broad clinical application. Ablative fractional laser treatment create vertical channels that might assist the delivery of drug into skin. Combination same-session therapy with ablative fractional laser and triamcinolone acetonide offer a good combination caused assisted delivery of drug.

Efficacy of fractional lasers in treating alopecia: a literature review.

Hair loss stemming from different types of alopecia, such as androgenic alopecia and alopecia areata, negatively affects over half the population and, in many circumstances, causes serious psychosocial distress. Current treatment options for alopecia, such as minoxidil, anthralin, and intralesional corticosteroids, vary efficacy and side effect profiles. It is known that low-level laser/light therapies (LLLT), or photobiomodulations, such as the US FDA-cleared HairMax Lasercomb®, He-Ne laser, and excimer laser, are relatively affordable, user-friendly, safe, and effective forms of treatment for hair loss. While less is known about the effectiveness of fractional lasers for combating hair loss, research suggests that by creating microscopic thermal injury zones, fractional lasers may cause an increase in hair growth from a wound healing process, making them potential therapeutic options for alopecia. A literature review was performed to evaluate the effectiveness of fractional lasers on hair regrowth. The specific fractional laser therapies include the 1550-nm nonablative fractional erbium-glass laser, the ablative fractional 2940-nm erbium:YAG laser, and the ablative fractional CO2 fractional laser. Additional randomized controlled trials are necessary to further evaluate the effectiveness of the lasers, as well as to establish appropriate parameters and treatment intervals.

Morphometric analysis of high-intensity focused ultrasound-induced lipolysis on cadaveric abdominal and thigh skin.

Non-focused ultrasound and high-intensity focused ultrasound (HIFU) devices induce lipolysis by generating acoustic cavitation and coagulation necrosis in targeted tissues. We aimed to investigate the morphometric characteristics of immediate tissue reactions induced by 2MHz, 13-mm focused HIFU via two-dimensional ultrasound images and histologic evaluation of cadaveric skin from the abdomen and thigh. Acoustic fields of a 2MHz, 38-mm HIFU transducer were characterized by reconstruction of the fields using acoustic intensity measurement. Additionally, abdominal and thigh tissues from a fresh cadaver were treated with a HIFU device for a single, two, and three pulses at the pulse energy of 130J/cm2 and a penetration depth of 13mm. Acoustic intensity measurement revealed characteristic focal zones of significant thermal injury at the depth of 38mm. In both the abdomen and thigh tissue, round to oval ablative thermal injury zones (TIZs) were visualized in subcutaneous fat layers upon treatment with a single pulse of HIFU treatment. Two to three HIFU pulses generated larger and more remarkable ablative zones throughout subcutaneous fat layers. Finally, experimental treatment in a tumescent infiltration-like setting induced larger HIFU-induced TIZs of an oval or columnar shape, compared to non-tumescent settings. Although neither acoustic intensity measurement nor cadaveric tissue exactly reflects in vivo HIFU-induced reactions in human tissue, we believe that our data will help guide further in vivo studies in investigating the therapeutic efficacy and safety of HIFU-induced lipolysis.

Randomized Controlled Trial of Intense Therapeutic Ultrasound for the Treatment of Chronic Plantar Fasciitis

Category: Sports Introduction/Purpose: Initial treatment of plantar fasciitis (PF), consisting of anti-inflammatories, stretching and in-shoe orthosis (heel pad, heel wedge, or arch support), leads to symptomatic resolution in over 90% of patients but takes 3-6 months. This study was conducted to test the effectiveness of a minimally invasive modality, intense therapeutic ultrasound (ITU), in accelerating the healing of chronic plantar fasciitis (PF). ITU uses high-frequency high-intensity focused ultrasound to create small thermal injury zones inside soft tissue without damage to surrounding structures. ITU has been shown to initiate a tissue repair cascade and promote collagen generation in dermal and musculoskeletal tissue and is FDA approved for use in non-surgical brow lifts [1,2]. The goal of this study was to determine if ITU when combined with standard therapy could speed the healing of chronic PF. Methods: 47 patients with chronic (greater than 3 months) heel pain due to PF were randomized to standard therapy (anti- inflammatory pills, stretching, and gel heel cups) plus ITU (“ITU”, n=33) or standard therapy plus sham ITU (“control”, n=14) groups. ITU treatments were administered at enrollment and two-weeks later using a custom 3.3 MHz therapeutic ultrasound system (Guided Therapy Systems, Mesa, AZ). Sham treatment utilized the same protocol but with the energy set to 0 Joules. Treatment effect was assessed at 2, 4, 6, and 12 weeks after the initiation of treatment using diagnostic ultrasound and patient reported outcomes (PROMIS physical function computer adaptive test, PROMIS global health, Foot Function Index pain subscale, and a non-validated heel pain specific questionnaire). Ultrasound images were analyzed to determine the size of lesions within the PF. Both the sonographer and the study coordinator administering the patient reported outcome instruments were blinded to group assignment. Results: 38 patients completed the 12 week study (ITU: n=37, Control: n=11.). The ITU group reported a significantly greater reduction in heel pain scores [Mean 8.27, SD 4.69, P=0.027] compared to the control group [Mean 2.25, SD 5.92] (Figure 1). Ultrasound imaging showed an 81% decrease in perifascial lesion size in the treatment group, compared to a 26% increase in lesion size in the control group (Figure 2). Conclusion: Preliminary results of this clinical study of noninvasive ITU for the treatment of chronic PF showed that ITU treatment as compared to sham control lead to a larger and more rapid reduction of heel pain and perifascial lesion size. ITU holds promise as a potential therapy to accelerate the healing of chronic plantar fasciitis

Coagulation and ablation patterns of high-intensity focused ultrasound on a tissue-mimicking phantom and cadaveric skin

High-intensity focused ultrasound (HIFU) can be applied noninvasively to create focused zones of tissue coagulation on various skin layers. We performed a comparative study of HIFU, evaluating patterns of focused tissue coagulation and ablation upon application thereof. A tissue-mimicking (TM) phantom was prepared with bovine serum albumin and polyacrylamide hydrogel to evaluate the geometric patterns of HIFU-induced thermal injury zones (TIZs) for five different HIFU devices. Additionally, for each device, we investigated histologic patterns of HIFU-induced coagulation and ablation in serial sections of cadaveric skin of the face and neck. All HIFU devices generated remarkable TIZs in the TM phantom, with different geometric values of coagulation for each device. Most of the TIZs seemed to be separated into two or more tiny parts. In cadaveric skin, characteristic patterns of HIFU-induced ablation and coagulation were noted along the mid to lower dermis at the focal penetration depth of 3 mm and along subcutaneous fat to the superficial musculoaponeurotic system or the platysma muscle of the neck at 4.5 mm. Additionally, remarkable pre-focal areas of tissue coagulation were observed in the upper and mid dermis at the focal penetration depth of 3 mm and mid to lower dermis at 4.5 mm. For five HIFU devices, we outlined various patterns of HIFU-induced TIZ formation along pre-focal, focal, and post-focal areas of TM phantom and cadaveric skin of the face and neck.

Histological studies of facial acne and atrophic acne scars treated with a bipolar fractional radiofrequency system.

Various fractional radiofrequency (FRF) treatments have demonstrated significant beneficial effects and minor side-effects on atrophic acne scars and acne vulgaris by creating micro-thermal injuries in the skins. However, histological studies to identify the precise mechanism responsible for the success of bipolar FRF treatments are lacking. In this study, six human subjects with these diseases were histologically analyzed after treatment with a bipolar FRF system (eMatrix; Syneron, Yokneam, Israel) and the effects of multiple passes were compared. Histopathological results showed that two-pass FRF treatment created deeper dermal thermal injury zones compared to one-pass treatment. Periadnexal collagen was coagulated, as well as that in the sebaceous glands, as evaluated in all cases with two-pass FRF treatment. No severe side-effects were observed after treatment. Our experience suggests that the level of dermal thermal injury is directly related to the number of passes, and that a large benefit of this treatment for these diseases is the preservation of adnexal structures.

Multiple fractional erbium: yttrium–aluminum–garnet laser sessions for upper facial rejuvenation: clinical and histological implications and expectations

Fractional photothermolysis is a modern resurfacing technique, in which microscopic zones of thermal injury are created, stimulating turnover of both epidermis and dermis. Fractional laser rejuvenation has been developed to overcome the drawbacks of traditional ablative laser. To objectively evaluate the effectiveness of multiple sessions of fractional Er:YAG laser rejuvenation for aging upper face clinically, histologically and immunohistochemically. Ten volunteers asking for facial rejuvenation were subjected to multiple sessions (3-5) of fractional Er:YAG laser. Clinical evaluation with both histopathological and immunohistochemical assessment for skin biopsies was carried out before, after 1month and 6months of laser resurfacing. Histometry for epidermal thickness and quantitative assessment for neocollagen formation, collagen I, III, and VII, elastin and tropoelastin were carried out for all skin biopsies. Comparing before, after 1month and 6months of fractional Er:YAG laser resurfacing resulted in improved clinical appearance with increased epidermal thickness (P<0.001). Dermal collagen showed increased neocollagen formation (P=0.006), with increased concentration of collagen types I (P<0.001), III (P<0.001), and VII (P=0.001). Dermal elastic tissue studies revealed decreased elastin, while tropoelastin concentration increased after laser resurfacing (P<0.001). An increase in collagen (I and III) and tropoelastin level and decreased elastin content was encountered with increasing the number of sessions, yet it was not significant. Multiple sessions are effective in rejuvenation of the aging face with high safety, short downtime, and no adverse effects. They stimulated formation of new collagen (type I, III, and VII) up to 6months after treatment with better improvement in skin texture and fine wrinkles. The variable number of fractional Er:YAG laser sessions (3-5) showed no significant difference as regards efficacy.

Histometric Analysis of Skin-Radiofrequency Interaction Using a Fractionated Microneedle Delivery System

Fractionated microneedle radiofrequency (RF) devices have been reported to be effective in treatment of various dermatologic disorders. To analyze histometric changes in skin-RF interactions using a fractionated microneedle delivery system. RF energies were delivered using a fractionated microneedle device to an in vivo minipig model with penetration depths of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.5mm; RF conduction times of 20, 50, 100, and 1,000ms; and energy levels of 5.0, 10.0, 20.0, 25.0, 37.5, and 50.0V. Immediately after treatment, skin samples showed that the RF-induced coagulated columns in the dermis formed a cocoon-shaped zone of sublative thermal injury. Fourdays after the treatment, skin specimens demonstrated reepithelialization, and the dermal RF-induced coagulated columns showed mixed cellular infiltration, neovascularization, and granulation tissue formation. Microneedle depth and RF conduction times, but not energy level, significantly affected histometric values of RF-induced dermal coagulation. Microneedle RF treatment affected adnexal structures by coagulating follicular epithelium and perifollicular structures. Our data may be of use as an essential reference for choosing RF parameters in treatment of various skin conditions.

Evaluation of EnSeal®, an adaptive bipolar electrosurgical tissue-sealing device

Relatively few, and inconsistent, data are available in the literature about the properties of EnSeal®, an electrosurgical tissue-sealing device. For this reason, we conducted control safety tests on experimental pigs. The mean burst pressure of sealed vessels (2-7 mm in diameter) proved to be 873.89 ± 120.57 mmHg (n = 60). Surface temperature increased to 69.25 ± 0.98 °C in average (n = 22). The mean diameter of the collateral microscopic thermal injury zone was found to be 0.28 ± 0.04 mm, and it did not show significant differences among the groups of tissues studied (n = 183). During our studies, the device worked reliably and met the relevant requirements in all cases. It can be established that EnSeal® enables high-safety clinical interventions at high blood pressure values, in different tissues and even at sites adjacent to heat-sensitive tissues, and thus it paves the way for new operative solutions in both human and veterinary surgery. In our opinion, the discrepancies between data reported in the literature arise from differences in the design of studies and in the designated limit values. To ensure standardisation, we recommend the use of the nitroblue-tetrazolium chloride/lactate dehydrogenase (NBTC/LDH) enzyme histochemical technique for studying thermal injury induced by the different performance levels and application times of devices operating with electromagnetic energy.

The study of laparoscopic electrosurgical instruments on thermal effect of uterine tissues

It is to compare the thermal damage on myometrium tissue caused by five electrosurgical instruments, including monopolar forceps, bipolar forceps, PK scalpel, Ligasure and BiClamp. Normal myometrium in vitro was collected and electric coagulation was conducted with five electrosurgical instruments under corresponding powers. The zones of thermal injury (ZTI) in each coagulation sites were examined histologically, while the width and depth of thermal damage were measured. 1. There were significant differences among various groups' widths of ZTI of myometrium (P < 0.05). Ligasure produced the greatest width of ZTI, and it was statistically greater than that of PK scalpel and BiClamp (P < 0.05). While the widths of ZTI caused by monopolar and bipolar electrocoagulation lied between that of Ligasure and PK scalpel, but the differences were of no statistical significance (P > 0.05). 2. The depths of ZTI in different groups were of significant differences (P < 0.05). Both monopolar and bipolar forceps had greater depths of ZTI compared with BiClamp (P < 0.05) but not had statistical differences with Ligasure and PK scalpel (P > 0.05). As for myometrium, the thermal damage is rather small in the horizontal and vertical directions when using BiClamp and PK scalpel. Ligasure places larger range of thermal damage in horizontal direction with little depth in vertical direction, which is rather safe when acting on uterine surface. Electrocoagulation was conducted with monopolar (the power is 55 W) and bipolar forceps (the power is 40 W) continuously for 3 s, whose thermal damage range is fairly safe to corpus uteri wall and fundus uteri.

A study of fractional CO2 laser resurfacing: the best fluences through a clinical, histological, and ultrastructural evaluation

Fractional resurfacing is a laser treatment modality to create numerous microscopic thermal injury zones of controlled width, depth, and density that are surrounded by a reservoir of spared epidermal and dermal tissue, allowing rapid repair of laser-induced thermal injury. To evaluate the safety and efficacy of a fractional CO(2) laser system in the treatment of photo-damaged skin with clinical, histological, and ultrastructural evaluation, with special attention to one of the parameters of this laser system: the fluences. Twelve patients with Fitzpatrick skin types II to III with photo-damage skin underwent fractional laser treatment with one single-pass superficial on the face and forearm. Clinical outcome and histological and ultrastructural changes were assessed. Light microscopy of biopsies gave important information about skin changes at three different times after fractional treatment, especially revealing some differences between the fluences used in the three groups of patients. Fractional resurfacing offers significant surgical advantages allowing to achieve excellent esthetic results in balance with the biological structure. Besides, our study shows already that with 2.07 and 2.77 J/cm(2) , instead of 4.15 J/cm(2) , it is possible to reach a biological response without scar formation.

Evaluation of a fractional laser with optical compression pins

Non-ablative fractional lasers have been used in skin rejuvenation procedures with some success. In general, the optimum area coverage and depths of the fractional thermal injury zones depend on the specific indications of interest. For all fractional devices, depth is adjusted with energy that also determines the coagulation area at the dermal/epidermal junction. Micro-beams (µB) of a 1,540 nm laser are co-aligned with optical pins in a device designed to provide skin compression during treatment to remodel the deeper reticular dermis and hypodermis while minimizing epidermal damage. The device is characterized in ex vivo and clinical studies. Ex vivo porcine skin was treated with a compression-pins optic connected to an Er:Glass laser hand piece. Nitroblue tetrazolium chloride (NBTC) cell viability staining of horizontal radial and vertical sections of post-treatment skin was used to assess coagulation profiles. A pilot clinical study was also performed to evaluate the effects of compression on epidermal injury. The compression-pins optic provided deeper coagulation to 1.5 mm depths and less epidermal injury than without compression. Coagulation depth was increased further with stacked pulses. The ability to de-couple depth of treatment from area coverage provides greater flexibility of treatments. The results promise greater possibilities to vary dermal injury patters which may offer increased benefit in treating a variety of cutaneous conditions.

The Dorsal Metacarpal Artery Perforator Flap: A Case Report Utilizing a Quaba Flap Harvested from a Previously Skin-Grafted Area for Dorsal 5th Digit Coverage

Burns to the hand are common in burn victims. These burns often leave complex wounds that require local flaps for coverage. Local flaps are often excluded because they lie within the zone of thermal injury. The purpose of this case report is to report the successful use of a Quaba flap harvested from a previously burned and skin-grafted area. The patient's medical record including pre-operative, intra-operative, and post-operative photographs were reviewed and utilized as sources of data. The patient tolerated the procedure well and was able to return to his previous hand therapy regimen without adverse event and with an acceptable cosmetic result. The Quaba flap can be a safe and effective option for local hand coverage even in previously burned and skin-grafted areas.