Treatment of hypertrophic scars using a long-pulsed dye laser with cryogen-spray cooling

Hypertrophic scars are common and cause functional and psychologic morbidity. The conventional pulsed dye laser (585 nm) has been shown previously to be effective in the treatment of a variety of traumatic and surgical scars, with improvement in scar texture, color, and pliability, with minimal side effects. This prospective study was performed to determine the effectiveness of the long-pulsed dye laser (595 nm) with cryogen-spray cooling device in the treatment of hypertrophic scars. Fifteen Asian patients with 22 hypertrophic scars were treated by the long-pulsed dye laser (595 nm) with cryogen-spray cooling device. In 5 patients, the scar area was divided into halves, one half of which was treated with the laser, whereas the other half was not treated and was used as a negative control. All patients received 2 treatments at 4-week intervals, and evaluations were done by photographic and clinical assessment and histologic evaluation before the treatment and 1 month after the last laser treatment. Treatment outcome was graded by a blind observer using the Vancouver General Hospital (VGH) Burn Scar Assessment Scale. Symptoms such as pain, pruritus, and burning of the scar improved significantly. VGH scores improved in all treated sites, and there was a significant difference between the baseline and posttreatment scores, corresponding to an improvement of 51.4 +/- 14.7% (P < 0.01). Compared with the baseline, the mean percentage of scar flattening and erythema elimination was 40.7 +/- 20.7 and 65.3 +/- 25.5%, respectively (P < 0.01). The long-pulsed dye laser (595-nm) equipped with cryogen spray cooling device is an effective treatment of hypertrophic scars and can improve scar pliability and texture and decrease scar erythema and associated symptoms.     

Control of hair growth using long-pulsed alexandrite laser is an efficient and cost effective therapy for patients suffering from recurrent pilonidal disease

Pilonidal sinus (PNS) and its surgical management have a profound impact on hospital resources in terms of finances and productive man-hours. Surgical treatment has been the mainstay of treatment of both acute and chronic pilonidal sinus but recurrence is common. The control of hair growth in the sinus region plays an important role in preventing recurrence. Here, we discuss our experience of treating 19 patients suffering from recurrent pilonidal sinus with laser depilation and its long-term cost effectiveness. This is a retrospective study on patients who had recurrence of pilonidal sinus following multiple surgical treatments. They were treated using long-pulsed alexandrite laser for depilation in the sinus area, an outpatient procedure. Their clinical characteristics and outcomes were then evaluated. There was a significant reduction in hair density after laser treatment (p?<?0.001). The disease-free period after laser treatment was significantly longer than that one after surgical treatment (p?<?0.001). The average cost of repeated surgical treatment per disease-free month was significantly higher than that of laser treatment (p?<?0.001). Evidence suggests the role of natal cleft hair growth in the evolution of the pilonidal disease; therefore, control of hair growth should be considered as an adjunct to the initial treatment via surgery. Compared to surgical treatment of recurrences, laser depilation is an efficient and cost-effective method of preventing recurrence and reducing morbidity and loss of man-hours. We suggest that laser depilation of the pilonidal sinus should be funded by clinical commissioning groups.     

Removal of unwanted hair: efficacy,tolerability, and safety of long-pulsed 755-nm alexandrite laser equipped with a sapphire handpiece

Due to the difference in refraction coefficients between air and the corneal epithelium, irradiation of the skin with a light source can lead to reflection of the energy and its leakage to the skin causes epidermal injury. All of which decreases the efficacy of treatment. We evaluated cooling sapphire handpieces’ efficacy in decreasing pain and epidermal injuries and enhancing the treatment outcome in laser hair removal. A total of 49 patients with Fitzpatrick skin types of II to IV were treated for laser hair removal on face, limbs, inguinal, and axillary areas with pulsed 755-nm alexandrite laser equipped with a sapphire handpiece and the cooling system. Hair counts were performed by two independent observers at the baseline and 3 months after the final treatment. A marked reduction in hair regrowth was noted 3 months after the final treatment in all body locations studied. Clinical hair reduction was observed and fully assessed. There were no serious side effects with an average pain score of 4.6 out of 40. The cooled sapphire cylinder tip has been shown to minimize epidermal injury and reduce the system energy leaks to the skin.     

Lithotripsy with a Q-switched alexandrite laser system. Preliminary in vivo and in vitro results.

An alexandrite laser system which emits a wavelength of 750 nm, has recently been proposed as a substitute for the pulsed-dye laser (504 nm) for laser lithotripsy. We have carried out in vitro lithotripsy trials in order to evaluate the efficiency of a flashlamp pumped Q-switched alexandrite laser. In the first experiment, we compared the Q-switched alexandrite laser to the pulsed-dye laser with respect to their effectiveness in fragmentizing urinary and model stones (HMT target stones). In the second experiment, we evaluated the effect of Q-switched alexandrite radiation on the urinary wall (bladder, ureter, renal pelvis and liver) of animals (Wistar rats and rabbits) under general anesthesia. In conclusion, the alexandrite laser system is comparable to the pulsed dye laser. The 750-nm wavelength involves minimal risk of damage to the urinary tract and constitutes a safe alternative, especially during blind lithotripsy. It is a compact solid-state system, with no toxic chemical agents as laser material.     

Ex vivo investigations of laser auricular cartilage reshaping with carbon dioxide spray cooling in a rabbit model

Laser cartilage reshaping (LCR) with cryogen spray cooling is a promising modality for producing cartilage shape change while reducing cutaneous thermal injury. However, LCR in thicker tissues, such as auricular cartilage, requires higher laser power, thus increasing cooling requirements. To eliminate the risks of freeze injury characteristic of high cryogen spray pulse rates, a carbon dioxide (CO₂) spray, which evaporates rapidly from the skin, has been proposed as the cooling medium. This study aims to identify parameter sets which produce clinically significant reshaping while producing minimal skin thermal injury in LCR with CO₂ spray cooling in ex vivo rabbit auricular cartilage. Excised whole rabbit ears were mechanically deformed around a cylindrical jig and irradiated with a 1.45-μm wavelength diode laser (fluence 12–14 J/cm² per pulse, four to six pulse cycles per irradiation site, five to six irradiation sites per row for four rows on each sample) with concomitant application of CO₂ spray (pulse duration 33–85 ms) to the skin surface. Bend angle measurements were performed before and after irradiation, and the change quantified. Surface temperature distributions were measured during irradiation/cooling. Maximum skin surface temperature ranged between 49.0 to 97.6 °C following four heating/cooling cycles. Significant reshaping was achieved with all laser dosimetry values with a 50–70 °C difference noted between controls (no cooling) and irradiated ears. Increasing cooling pulse duration yielded progressively improved gross skin protection during irradiation. CO₂ spray cooling may potentially serve as an alternative to traditional cryogen spray cooling in LCR and may be the preferred cooling medium for thicker tissues. Future studies evaluating preclinical efficacy in an in vivo rabbit model are in progress.     

A case of labial lentigines in Peutz-Jeghers syndrome treated using a Q-switched alexandrite laser

Peutz-Jeghers syndrome (PJS) is a polygenic autosomal dominant disease characterized by multiple gastrointestinal polyps and pigmentation of the mucosa and skin. While there are a few reports regarding successful treatment of intestinal polyps in PJS, there is little research regarding treatment of mucocutaneous melanosis. This study investigated the many advantages of using a Q-switched alexandrite laser to treat mucocutaneous melanosis. In this case, a 19-year-old male with PJS presented with labial lentigines and received two Q-switched alexandrite laser treatments in 2018. Subsequently, the efficacy of the treatment was evaluated. The result of the evaluation was that, after the two laser treatments, the labial lentigines were successfully removed, and there were no complications.     

Treatment of leg telangiectasia by using a long-pulse dye laser at 595 nm with and without dynamic cooling device

BACKGROUND AND OBJECTIVE: The long-pulse dye laser (PDL) at 595 nm and pulse duration of 1.5 msec has been shown to improve clearance of larger vessels such as those seen in leg telangiectasia. The objectives of this study are twofold. First, to determine the effect of the dynamic cooling device (DCD) in clearance of leg telangiectasia by using a long-pulse PDL at 595 nm. Next, to determine the effect of the DCD in reducing transient discomfort associated with treatment and in reducing epidermal damage (blistering, hyper/hypopigmentation, scarring) caused by the laser. STUDY DESIGN/MATERIALS AND METHODS: Matched treatment sites were compared at energy densities of 20 and 24 J/cm(2) with and without the use of the cryogen spray in 18 patients. In areas treated without the DCD, the laser pulse was delivered through a single layer of Spenco Second Skin. Patients received two treatments 6 weeks apart. Discomfort ratings, clearance of leg telangiectasia, and complications were assessed at 6 weeks, 12 weeks, and 6 months. RESULTS: A reduction in discomfort ratings was found in most patients using the DCD. Six-month follow-up data revealed at the 20 J/cm(2) treatment sites, with or without the DCD, 76.9% showed greater than 50% clearance. At the 24 J/cm(2) treatment sites, with or without the DCD, 84.6% showed greater than 50% clearance. CONCLUSION: The long-pulse dye laser at 595 nm with a 1.5-msec pulse duration cleared leg telangiectasia an average of 67.5% with two treatments at 6 months. The major effect of the DCD was on pain reduction. There was no difference in clearance rates when using the DCD vs. cooled Second Skin. Further studies with longer cooling times with the DCD are needed to optimize treatment parameters.     

Microvascular anastomosis using the vascular closure device in free flap reconstructive surgery: A 13-year experience

The achievement of patency of the microvascular anastomosis in free flap surgery is dependent on a number of factors, central to which is atraumatic handling of the vessel lumen, and intimal apposition. Initial laboratory studies demonstrating the superiority of the non-penetrating vascular closure staple (VCS - Anastoclip ?) were followed by our report in 1999 on a series of free flaps. There is still a paucity of data in the literature on the use of non-penetrating devices for microvascular anastomosis, and our review gives evidence to support the routine use of the VCS in microsurgical free flap surgery. We now report on its successful use over a thirteen year period in 819 free flap reconstructions. Our data indicates the VCS device to be as effective as sutured anastomoses in free tissue transfer surgery. There is also statistically significant data (Barnard's Exact Test) to demonstrate a higher vascular patency rate of the VCS device over sutured anastomoses when sub group analysis is performed. 'Take-back' revision rates were lower amongst flaps that employed VCS use. For arterial anastomoses, this equated to 3/654(0.05%) vs 4/170(2.4%) with hand-sewn anastomoses (p?=?0.02). Similarly, for venous anastomoses the 'take-back' revision rate was 7/661(1.1%) vs 8/165(4.8%) with hand-sewn anastomoses (p?=?0.003). Furthermore, the major advantage of the VCS is reduction in anastomosis time, from approximately 25?min per anastomosis for sutures to between five and 10?min for staples.     

Possibilities of reconstructive plastic surgery in the treatment of vascular malformations of the head region

Results of treatment of 19 patients, suffering vascular malformation of the head region, were analyzed. Application of a new highly informative diagnostic methods of surgical intervention differential methods have promoted significant clinical improvement.     

Cold air in laser therapy: first experiences with a new cooling system

BACKGROUND AND OBJECTIVE: Analgesic cooling technologies are firmly established in dermatologic laser therapy. We present cold air as a novel method of cooling and compare it with those methods that are already in use. STUDY DESIGN/MATERIALS AND METHODS: We treated 166 patients with the diagnoses hypertrichosis, port wine stains, hemangioma, essential telangiectasias, and tattoos with different laser systems (long-pulsed alexandrite laser [LPIR], pulsed dye laser, Q-switched Nd:YAG laser, Q-switched ruby laser). In a prospective study, we collected data about the analgesia of the cooling method and the thermal protection of the epidermis (reduction of the extent and duration of erythema, purpura, blisters, hyper-/hypopigmentations, edemas, crusting), compared with the cooling method with ice gel. Additionally, we measured air and skin temperatures with an infrared thermometer at different application modalities. RESULTS: Three percent of the treated patients refused the cold air therapy altogether. Eleven percent found that it was as good as the other cooling methods; 86% clearly preferred the cold air therapy. Leaving out the perinasal area, the percentage rises to 97%. On average, the analgesic effect was by 37% better than through cooling with ice gel. The increased thermal protection of the epidermis made it possible to use laser energy levels that were higher by 15-30% and, at the same time, to reduce the rate of side effects (in 63% of the patients erythema persisted for a shorter period, in 70% the purpura was reduced, 83% had less crusting). CONCLUSION: In dermatologic laser therapy, the use of cold air in analgesia can be considered as an effective, inexpensive, and well-accepted (by both patients and doctors) alternative to currently applied cooling methods. Nevertheless, further prospective studies are necessary to determine whether treatment results can really be improved by using higher laser energy levels.     

Influence of nozzle-to-skin distance in cryogen spray cooling for dermatologic laser surgery

BACKGROUND AND OBJECTIVE: Cryogen sprays are used for cooling human skin during various laser treatments. Since characteristics of such sprays have not been completely understood, the optimal atomizing nozzle design and operating conditions for cooling human skin remain to be determined. MATERIALS AND METHODS: Two commercial cryogenic spray nozzles are characterized by imaging the sprays and the resulting areas on a substrate, as well as by measurements of the average spray droplet diameters, velocities, temperatures, and heat transfer coefficients at the cryogen-substrate interface; all as a function of distance from the nozzle tip. RESULTS: Size of spray cones and sprayed areas vary with distance and nozzle. Average droplet diameter and velocity increase with distance in the vicinity of the nozzle, slowly decreasing after a certain maximum is reached. Spray temperature decreases with distance due to the extraction of latent heat of vaporization. At larger distances, temperature increases due to complete evaporation of spray droplets. These three variables combined determine the heat transfer coefficient, which may also initially increase with distance, but eventually decreases as nozzles are moved far from the target. CONCLUSIONS: Sprayed areas and heat extraction efficiencies produced by current commercial nozzles may be significantly modified by varying the distance between the nozzle and the sprayed surface.     

Q-switched ruby versus long-pulsed dye laser delivered with compression for treatment of facial lentigines in Asians

BACKGROUND AND OBJECTIVES: Q-switched lasers have been used for the treatment of lentigines but post-inflammatory hyperpigmentation (PIH) can be an issue especially in Asians. The 595 nm long-pulsed dye laser (LPDL) has been used for the treatment of vascular lesions and although it is well absorbed by oxyhemoglobin, it is also absorbed by melanin. To use this device for the treatment of facial lentigines, we attached a flat glass lens to the tip of the laser's handpiece, allowing compression of the skin during treatment. In doing so, eliminated the absorption by oxyhemoglobin. This prospective study aims to compare the efficacy and complications of such an approach to the use of Q-switched ruby laser (QSRL) in the treatment of facial lentigines in Asians. STUDY DESIGN/MATERIALS AND METHODS: Eighteen Asian patients (1 male, 17 female) with facial lentigines Fitzpatrick skin types III-IV were enrolled. One of the lentigines present was treated with LPDL by compression method and the other one was treated with QSRL. A LPDL emitting wavelength of 595 nm, spot size of 7 mm was used, with fluence between 10 and 13 J/cm(2) and pulse duration of 1.5 milliseconds. Cryogen spray cooling was not used. A 694 nm QSRL was used with a spot size of 4 mm, fluence of 6-7 J/cm(2), and pulse duration of 30 nanoseconds. Lightening of the lesions was assessed by reflectance spectrometer Erythema, hypo- or hyperpigmentation and scarring were also assessed by clinical examinators. RESULTS: The degree of clearing achieved with the two lasers was 70.3% and 83.3% for QSRL and LPDL, respectively. All QSRL treated areas developed erythema whereas only 4 of 18 LPDL treated areas developed erythema. Hyperpigmentation was seen in four patients after QSRL, but not after LPDL. There was no scarring or hypopigmentation. CONCLUSIONS: LPDL delivered with a compression method is more effective than QSRL for facial lentigines. Complications after LPDL treatment were substantially less frequent than after QSRL. The addition of compression technique may allow "vascular" pulsed dye laser to be used for treating a variety of pigmented lesions.     

A new mathematical model for accurate quantification of cryogen spray cooling in cutaneous laser surgery using realistic boundary conditions

Lasers in Medical Science - Laser dermatologic surgery is widely used for various skin diseases. Prior to the laser treatment, transient cryogen spray cooling (CSC) is employed to prevent unwanted...     

Evaluation comparing multiple treatments with a 2-msec and 10-msec alexandrite laser for hair removal.

BACKGROUND AND OBJECTIVES: There are a variety of different laser hair removal systems currently available. There are also systems with identical emitted wavelengths; yet their emitted pulse durations vary. There are few data comparing these systems in an objective manner. STUDY DESIGN/MATERIALS AND METHODS: Fourteen subjects received three treatments with two different pulse duration 755-nm alexandrite lasers. Paired anatomic sites were treated three times with both a 2-msec and a 10-msec system. Subjects were evaluated prior to laser treatment and 6 months after the three treatments with manual hair counts and incidence of complications. RESULTS: The average percentage of hair reduction was 33.1% for the 2-msec-pulse duration and 33.9% for the 10-msec-pulse duration alexandrite laser. No cutaneous pigmentary changes or scarring was noted 6 months after the final treatment. CONCLUSION: The alexandrite laser is effective in removing unwanted hair. There was no difference in response between a 2-msec and a 10-msec alexandrite laser.