Wavelength-dependent threshold fluences for melanosome disruption to evaluate the treatment of pigmented lesions with 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.

BACKGROUND AND OBJECTIVES: A threshold fluence for melanosome disruption has the potential to provide a robust numerical indicator for establishing clinical endpoints for pigmented lesion treatment using a picosecond laser. Although the thresholds for a 755-nm picosecond laser were previously reported, the wavelength dependence has not been investigated. In this study, wavelength-dependent threshold fluences for melanosome disruption were determined. Using a mathematical model based on the thresholds, irradiation parameters for 532-, 730-, 755-, 785-, and 1064-nm picosecond laser treatments were evaluated quantitatively. STUDY DESIGN/MATERIALS AND METHODS: A suspension of melanosomes extracted from porcine eyes was irradiated using picosecond lasers with varying fluence. The mean particle size of the irradiated melanosomes was measured by dynamic light scattering, and their disruption was observed by scanning electron microscopy to determine the disruption thresholds. A mathematical model was developed, combined with the threshold obtained and Monte Carlo light transport to calculate irradiation parameters required to disrupt melanosomes within the skin tissue. RESULTS: The threshold fluences were determined to be 0.95, 2.25, 2.75, and 6.50 J/cm² for 532-, 730-, 785-, and 1064-nm picosecond lasers, respectively. The numerical results quantitatively revealed the relationship between irradiation wavelength, incident fluence, and spot size required to disrupt melanosomes distributed at different depths in the skin tissue. The calculated irradiation parameters were consistent with clinical parameters that showed high efficacy with a low incidence of complications. CONCLUSION: The wavelength-dependent thresholds for melanosome disruption were determined. The results of the evaluation of irradiation parameters from the threshold-based analysis provided numerical indicators for setting the clinical endpoints for 532-, 730-, 755-, 785-, and 1064-nm picosecond lasers.

The use of fractional radiofrequency in Asian patients to improve skin texture.

BACKGROUND AND OBJECTIVES: Fractional radiofrequency devices have been demonstrated to improve skin texture, such as smoothness, rhytides, brightness, and atrophic acne scars, by increasing dermal thickness, dermal collagen content, and dermal fibrillin content. The objective of the study is to assess the efficacy and adverse effects of this device on Asian patients of skin type III and IV with skin textural changes. MATERIALS AND METHODS: The study was designed as a prospective, open-labeled single-arm study, which was conducted with 20 Chinese patients aged 21-60 years and having irregularities in their skin texture, rhytides, and acne scars. The patients received six treatments at intervals of 4 weeks. Treatment was initiated with the maximum energy tolerated, which was then adjusted during the course of treatment if the patients felt excessive discomfort. A total of two passes were delivered in each session. Physician assessment results and standardized photographs were collected at the baseline, after all treatment visits, and at 1, 2, and 6 months after the final treatment visit. RESULTS: A total of 17 patients completed the study according to the established protocol. At the 6-month follow-up, 71% of patients were satisfied and 24% of patients were very satisfied with the received treatments, and the treatment physician reported varying degrees of improvement based on the global assessment scale in 60% of the subjects. While the anticipated side effects, such as erythema, edema, pinpoint bleeding, scab formation, and flare of acne, were noted in the patients, no serious adverse effects occurred. CONCLUSION: The use of fractional radiofrequency improves skin texture and is safe for use in Asian patients of skin type III and IV. No long-term serious adverse effects were noted.

Prospective comparison study of a 550 picosecond 755 nm laser vs a 50 ns 755 nm laser in the treatment of nevus of Ota.

Since the introduction of selective photothermolysis, Q-switched nanosecond lasers have been used for the treatment of dermal pigmented lesions. Over the past several years, picosecond lasers have been introduced to the cosmetic community. We recently performed a study comparing a 550 picosecond 755 nm laser versus a 50 ns 755 nm laser, with the purpose of evaluating the clinical efficacy and complications of each laser when treating nevus of Ota. Ten Asian patients with nevus of Ota were enrolled in the study. Each lesion was split into 2 parts, and patients were treated with a 755 nm picosecond laser (PSL) and a 755 nm nanosecond laser (NSL). The clinical endpoint for fluence choice was immediate whitening (PSL: 2.33 ~ 3.36 J/cm2, NSL: 5.5 ~ 7 J/cm2) of the treated area. The pulse duration was fixed at 550 picoseconds (PSL) and 50 ns (NSL). The spot size of each laser was 2.5-3 mm. Laser treatments were performed until excellent clinical improvement was observed. Patients were examined 1 week after the first treatment, at each follow-up visit, and 6 months after the last laser treatment. The average number of treatment sessions to achieve excellent clinical improvement was 4.2 treatments using PSL and 5.4 treatments using NSL. One case of hyperpigmentation and one case of hypopigmentation were observed in the NSL treatment group. There were no complications in the PSL treatment group. The 755 nm 550 picosecond laser is significantly more effective than the 755 nm 50 ns laser in the treatment of nevus of Ota. The PSL treatment group also had minimum side effects.

Current Status of Early Complications Caused by Hyaluronic Acid Fillers: Insights From a Descriptive, Observational Study of 41,775 Cases.

BACKGROUND: The number of hyaluronic acid (HA) filler treatments has increased in recent years. Although extremely rare, serious complications associated with these treatments, such as skin necrosis, blindness, and stroke caused by vascular compromise, have been reported. OBJECTIVES: To evaluate the specific details related to early complications caused by HA filler injection in our group, understand the current status, and gain further insights from the findings. METHODS: A nationwide, observational, descriptive, multicenter, retrospective study was conducted. Of the 41,775 cases (58,533 sites of injection), 29 cases of early complications (onset of less than 14 days after injection) were included in the study. RESULTS: The injection site with the highest rate of early complications was the upper eyelids (0.41%; n = 1/241 sites). The most commonly injected site was the nasolabial fold (n = 13/29 cases), and the most common early complication was vascular compromise (n = 18/29 cases). The average experience of the injectors was 28.7 ± 31.9 months. CONCLUSIONS: All 13 patients injected in the nasolabial fold experienced vascular compromise, potentially related to the anatomical feature of a facial artery running parallel to the nasolabial fold, which is commonly found in Asian populations. Regardless of the injection site, accurate anatomical knowledge and knowledge and experience regarding HA fillers, including appropriate patient selection and injection techniques, are strictly required for injectors to anticipate early complications. Therefore, it is important to establish original guidelines based on experience and ensure their thorough implementation in our facilities.

A core outcome domain set for clinical research on capillary malformations (the COSCAM project): an e-Delphi process and consensus meeting.

BACKGROUND: There is limited evidence on the best available treatment options for capillary malformations (CMs), mainly due to the absence of uniform outcome measures in trials on therapies. A core outcome set (COS) enables standard reporting of trial outcomes, which facilitates comparison of treatment results. OBJECTIVES: To develop a core outcome domain set (CDS), as part of a core outcome set (COS), for clinical research on CMs. METHODS: Sixty-seven potentially relevant outcome subdomains were recognized based on the literature, focus group sessions, and input from the COSCAM working group. These outcome subdomains were presented in an online Delphi study to CM experts (medical specialists and authors of relevant literature) and (parents of) patients with CM (international patient associations). During three e-Delphi study rounds, the participants repeatedly scored the importance of these outcome subdomains on a seven-point Likert scale. Participants could also propose other relevant outcome subdomains. Consensus was defined as ≥ 80% agreement as to the importance of an outcome subdomain among both stakeholder groups. The CDS was finalized during an online consensus meeting. RESULTS: In total 269 participants from 45 countries participated in the first e-Delphi study round. Of these, 106 were CM experts from 32 countries, made up predominantly of dermatologists (59%) and plastic surgeons (18%). Moreover, 163 (parents of) patients with CM from 28 countries participated, of whom 58% had Sturge-Weber syndrome. During the two subsequent e-Delphi study rounds, 189 and 148 participants participated, respectively. After the entire consensus process, consensus was reached on 11 outcome subdomains: colour/redness, thickness, noticeability, distortion of anatomical structures, glaucoma, overall health-related quality of life, emotional functioning, social functioning, tolerability of intervention, patient satisfaction with treatment results, and recurrence. CONCLUSIONS: We recommend the CDS to be used as a minimum reporting standard in all future trials of CM therapy. Our next step will be to select suitable outcome measurement instruments to score the core outcome subdomains. What is already known about this topic? Besides physical and functional sequelae, capillary malformations (CMs) often cause emotional and social burden. The lack of uniform outcome measures obstructs proper evaluation and comparison of treatment strategies. As a result, there is limited evidence on the best available treatment options. The development of a core outcome set (COS) may improve standardized reporting of trial outcomes. What does this study add? A core outcome domain set (CDS), as part of a COS, was developed for clinical research on CMs. International consensus was reached on the recommended core outcome subdomains to be measured in CM trials: colour/redness, thickness, noticeability, distortion of anatomical structures, glaucoma, overall health-related quality of life, emotional functioning, social functioning, tolerability of intervention, patient satisfaction with treatment results, and recurrence. This CDS enables the next step in the development of a COS, namely to reach consensus on the core outcome measurement instruments to score the core outcome subdomains. What are the clinical implications of this work? The obtained CDS will facilitate standardized reporting of treatment outcomes, thereby enabling proper comparison of treatment results. This comparison is likely to provide more reliable information for patients about the best available treatment options.

Mechanism of crescent-shaped and ring-shaped epidermal damage from laser hair removal with cryogen spray cooling.

The safety and efficacy of laser hair removal have been well established through many clinical studies and through clinical use over the past 25 years. A laser hair removal device that protects the epidermis by utilizing cryogen spray cooling (CSC) is widely used internationally. In darker skin types, post-inflammatory hyperpigmentation (PIH) can occur after laser hair removal. In particular, laser hair removal with CSC is known to cause crescent-shaped or ring-shaped PIH. In this experiment, we report a visualization of this PIH mechanism. The laser used in this experiment is a 755-nm-long-pulsed alexandrite laser. Graph paper was treated with this laser to assess for thermal damage. We investigated changes in thermal damage due to differences in laser spot size, fluence output, and laser beam angle in relation to the graph paper. When using a spot size of 18 mm, we observed that higher fluences caused crescent-shaped thermal damage on the margins of the treated graph paper. It was also confirmed that when the hand piece is not held perpendicular to the skin, the laser-treated area is expanded and the CSC range is narrowed. These factors caused the area of thermal damage to widen. This widening causes ring-shaped thermal injury, leading to PIH. We treated graph paper using a hair removal laser with CSC to investigate the mechanism of crescent or ring-shaped thermal damage. Laser treatment on graph paper is effective as a test for defects in the CSC device. Factors that cause inadequate cooling, which leads to PIH, are large spot size, high fluence, not holding the laser hand piece perpendicular to the skin, and malfunctioning of CSC device.

Hetero-Type Benzannulation Leading to Substituted Benzothio-Phenes.

TiCl4 (or SnCl4)-promoted hetero-type benzannulation reactions using various (2,2-dichlorocyclopropyl)(thiophen-2-yl)methanols proceeded smoothly to produce uniquely substituted 4-chlorobenzothiophenes (five examples). The present approach involves the first distinctive thiophene formation from thiophene cores, in contrast to traditional methods of thiophene formation from benzene cores. The stereocongested (less reactive) Cl position in the obtained 4-chlorobenzothiophenes functioned successfully as the partners of three cross-coupling reactions: (i) a Suzuki-Miyaura cross-couplings using Pd(OAc)2/SPhos/K3PO4 catalysis (seven examples; 63-91%), (ii) a hydroxylation using KOH/Pd(dba)2/tBu-XPhos catalysis (85%), and (iii) a borylation using a B2(pin)2/Pd(dba)2/XPhos/NaOAc catalysis-provided 4-(pin)B-benzothiophene (58%).

A retrospective analysis on the management of pigmented lesions using a picosecond 755-nm alexandrite laser in Asians.

BACKGROUND AND OBJECTIVES: Photo-aging in Chinese often presents with benign pigmentary lesions. Q-switched lasers for pigmentary lesions in Asians had reported a risk of post-inflammatory hyperpigmentation (PIH) up to 25%. Longer pulse widths in the millisecond domains were advocated with reduced risk of PIH. Recently, picosecond lasers of various wavelengths were introduced with proven efficacy in tattoo removal. The objective of this study is to assess the efficacy and safety of a novel picosecond 755-nm alexandrite laser for the treatment of benign pigmented lesions in Asians retrospectively. METHODS: A list of all patients who received picosecond 755-nm alexandrite laser treatment at a private dermatology center in Hong Kong was included. Those who had any other laser or topical treatment during the period of picosecond laser treatment were excluded. The age, skin phototype, type of pigmentary lesion, number of treatments performed was recorded. The baseline and most recent standardized photographs were assessed by trained physicians for comparison. A score of 0-4, representing poor 0-24%, fair 25-49%, good 50-74%, excellent 75-95%, and complete 95%+ improvement was given. Adverse events associated with the laser treatment were also recorded. All patients were followed up until 6 months after the last laser session. RESULTS: A total of 13 subjects were included in the present study. The number of treatment sessions received ranged from one to seven. The benign pigmentary lesions consist of Nevus of Ota, café-au-lait patches, lentigines, Becker's nevus, Hori's macules, and nevus spilus. Among patients with Nevus of Ota, one patient achieved complete clearance after four treatments and two other patients had excellent clearance after three and four sessions, respectively. Patients with café-au-lait had fair to good clearance after one to seven treatment sessions. One patient who has Hori's macules was resistant to laser treatments and a fair response was achieved after eight treatments. In the present series, two patients (4.8%) developed transient hypopigmentation, which had improved upon subsequent follow-up in both cases and none had post-inflammatory hyperpigmentation. CONCLUSIONS: The novel picosecond 755-nm alexandrine laser is effective for the treatment of benign pigmentary lesions in Chinese, especially for the clearance of Nevus of Ota. Picosecond laser appears to be associated with a much lower risk of PIH for treatment of pigmentary lesions in Asians.

Long-term results of nail correction with double wires for pincer nail deformity: A retrospective cohort study.

There is no consensus on the best treatment for pincer nail deformity. We developed a novel procedure that uses double wires to treat pincer nail deformity on the great toe. This study aimed to describe this technique for pincer nail deformity treatment and present the long-term findings/observations. After injecting a local anesthetic, a mini router was used to make holes on both sides of the nail plate edge, and the wire was inserted in two places, one proximal and the other distal to the great toenail. The wire was removed when it moved to the tip of the great toe as the nail grew. Patients who underwent this method were evaluated retrospectively from 2014 to 2020. Patients with less than 24 months of follow-up were excluded. If pain occurred again, it was deemed as a recurrence. A total of 27 patients (36 toes, mean age: 69.5 years) were evaluated. In all cases, the pain disappeared 1 week after the procedure. In the correction period (mean 2.7 months), six toes had complications (nail break, four toes and nail hold pain, two toes), while recurrence occurred in four toes within 2 years. Curvature (nail tip height/width of nail tip × 100%) improved significantly up to 1-year post-procedure (37.7 ± 14.4%, p < 0.05) as compared to pre-correction (53.8 ± 24.7%). The procedure time was short (approximately 10 minutes), and the treatment was completed with a single procedure. In addition, the recurrence rate was low.

Wound dressing material containing lyophilized allogeneic cultured cells.

Although topical application of a single growth factor is known to accelerate wound healing, treatment with allogeneic cultured cells is more efficient and physiological, because they release various mediators that interact and regulate the wound healing mechanism. However, in clinics, the cells must be cryopreserved until use. To overcome this inconvenience, we designed novel wound dressing materials containing lyophilized allogeneic cultured epithelial cells and/or fibroblasts. This study aimed to confirm growth factor release from those lyophilized products. The results revealed that the cultured cells retained their morphology even after lyophilization and released growth factors. When fibroblasts were used alone, they released growth factors in significantly higher concentrations after lyophilization than after cryopreservation. In particular, bFGF release was almost a hundredfold higher in the lyophilized group compared to the cryopreserved group. When epithelial cells and fibroblasts were co-cultured, both bFGF and VEGF were released in higher concentrations by the cryopreserved dressing material than by the lyophilized dressing material. The growth factors' release was probably regulated by interaction between epithelial cells and fibroblasts. We speculate that repeated application may be necessary for treating difficult wounds with the lyophilized product, because the lyophilized cells release the mediators in a single, transient burst.

A review of the metabolism of 1,4-butanediol diglycidyl ether-crosslinked hyaluronic acid dermal fillers.

BACKGROUND: Cosmetic procedures are growing ever more common, and the use of soft tissue fillers is increasing. Practicing physicians need to be aware of the biological behavior of these products in tissue to enable them to respond to any safety concerns that their patients raise. OBJECTIVES: To provide an overview of the metabolism of 1,4-butanediol diglycidyl ether (BDDE)-crosslinked hyaluronic acid (HA) dermal fillers and to examine the safety of the resulting byproducts. METHODS: A review of available evidence was conducted. RESULTS: After reaction with HA, the epoxide groups of BDDE are neutralized, and only trace amounts of unreacted BDDE remain in the product (<2 parts per million). When crosslinked HA, uncrosslinked HA, and unreacted BDDE degrade, they break down into harmless byproducts or into byproducts that are identical to substances already found in the skin. CONCLUSION: Clinical and biocompatibility data from longer than 15 years support the favorable clinical safety profile of BDDE-crosslinked HA and its degradation products. Given the strength of the empirical evidence, physicians should be confident in offering these products to their patients.

Treatment of Ecchymosis with a Pulsed Dye Laser.

Ecchymosis is a common side effect after injury and surgery. A pulsed dye laser (PDL) is the gold standard for vascular lesions and can minimize ecchymosis. Heating induces hemoglobin modification due to oxidative and heat reactions with the formation of bilirubin and methemoglobin, resulting in color changes to brown-yellow. Therefore, downtime following cosmetic procedures can be shortened.

Preliminary report of novel technique for cryopreservation--vacuum-assisted cryoprotectant infiltration.

To date, cryopreservation of large soft tissues has not been successfully achieved because of limitation of cryoprotective agent (CPA) infiltration into the tissue. This study aimed to investigate the effects of a vacuum on the tissue-infiltration of a CPA. An instant pickle-maker was modified for use as a vacuum apparatus, and glycerol was selected as the CPA. Twenty-six rats were used, and their thighs were divided into three treatment groups. Group 1: fresh control; Group 2: cryopreserved control, i.e., immersed in the CPA for 1h under atmospheric pressure and cryopreserved; Group 3: vacuum-assisted CPA infiltration, i.e., immersed in the CPA under negative pressure (20, 40 and 60 cmHg, for durations of 10, 20 and 30 min at each) and cryopreserved. The Groups 2 and 3 specimens were thawed after 3 weeks of cryopreservation at -80 °C and histologically examined, in comparison with Group 1. Skin: in Groups 2 and 3, the skin was well preserved. Muscle: in Group 2, both extracellular and intracellular ice crystal formation was widely distributed throughout the muscle tissue. In Group 3, under an adequate vacuum, the muscle tissue was well preserved, with no ice crystal formation. However, when the treatment was conducted under excessive vacuum conditions, the muscle tissue showed focal necrosis. Blood vessels: in Group 3, both the arteries and veins were well preserved up to the tunica intima. The method described in this paper may be a useful technique for achieving cryopreservation of large soft tissues.

Deep vein thrombosis after total knee or hip arthroplasty is associated with increased preoperative calf muscle deoxygenation as measured by near-infrared spectroscopy.

OBJECTIVE: To assess whether the preoperative level of deoxygenated hemoglobin (HHb) in the calf muscle during light-intensity exercise is useful for identifying patients at risk of developing deep vein thrombosis (DVT) after total knee or hip arthroplasty. METHODS: Sixty-eight patients undergoing total knee or total hip arthroplasty were enrolled. The Caprini risk assessment model was used to stratify patients into Caprini 5 to 6, Caprini 7 to 8, and Caprini >8 groups. The preoperative diameter of each venous segment was measured, and the time-averaged velocity (TAV) and time-averaged flow (TAF) of the popliteal vein (POPV) were assessed. Moreover, the prevalence of venous reflux in the POPV was evaluated preoperatively. Near-infrared spectroscopy (NIRS) was used to measure the calf muscle HHb level. The calf venous blood filling index (FI-HHb) was calculated on standing, and then the calf venous ejection index (EI-HHb) was obtained after one tiptoe movement and the venous retention index (RI-HHb) after 10 tiptoe movements. All patients received low-dose unfractionated heparin preoperatively and fondaparinux for postoperative thromboprophylaxis. Patients with arterial insufficiency, those who had preoperative DVT, and those who developed bilateral DVT after surgery were excluded from the study. RESULTS: Four patients were excluded on the basis of the exclusion criteria. Among the 64 patients evaluated, 14 (21.9%) were found to have DVT postoperatively. Among the risk factors for DVT, only the previous DVT was significantly predominant in patients who developed DVT (P = .001). The diameter of the popliteal vein was significantly smaller in patients who developed postoperative DVT than in those who did not (P = .001). Similarly, the diameter of the gastrocnemius vein was significantly larger in patients with postoperative DVT than in those without (P = .010). TAV and TAF were significantly increased in the popliteal vein in patients who developed postoperative DVT (P = .043, 0.046, respectively). Both groups showed a similar prevalence of reflux in the POPV (P = .841). The preoperative NIRS-derived RI was significantly increased in patients who developed DVT relative to those who did not (P = .004). The RI increased as the Caprini score progressed; however, there were no statistically significant differences between the three categories. Using ultrasound- and NIRS-derived parameters of significance as a unit of analysis, an optimal RI cut-off point of >2.3 showed the strongest ability to predict postoperative DVT, followed by a cut-off point >0.25 cm for the diameter of the gastrocnemius vein (GV). CONCLUSIONS: NIRS-derived RI >2.3 may be a promising parameter for identifying patients at risk of developing postoperative DVT despite pharmacologic DVT prophylaxis. A GV diameter of >0.25 cm also seems to contribute to the development of postoperative DVT. These results might be helpful to physicians for deciding which patients require more intensive thromboprophylaxis.

Liposome-encapsulated 0.5% 5-aminolevulinic acid with intense pulsed light for the treatment of inflammatory facial acne: a pilot study.

BACKGROUND: Liposome used in spray form to encapsulate and deliver 5-aminolevulinic acid (5-ALA) into the pilosebaceous unit lowers the concentration of 5-ALA to 0.5% in photodynamic therapy (PDT) for acne, with low post-treatment photosensitivity. OBJECTIVE: To investigate the clinical outcome and side effects of PDT using intense pulsed light (IPL) and 0.5% 5-ALA spray for inflammatory facial acne in Asian skin. METHODS: Twelve subjects (skin types IV-V) with facial acne received full-face treatment at 3-week intervals with IPL 1 hour after being sprayed with 5-ALA. Lesion counts were assessed using serial standardized photographs taken up to 6 months after treatment. Serial sebum measurement and subjective assessment was conducted. RESULTS: There were mean reductions in inflammatory lesions of 52% at 1 month (p=.02) and 65% at 6 months (p=.04) after treatment. Mean subjective acne score decreased from 6.6 to 4.5 (on a scale from 1 to 10) 1 month after treatment. Significant reduction in sebum production was noted only on the forehead. No significant side effects, including postinflammatory hyperpigmentation and phototoxicity, were observed. CONCLUSION: Use of 0.5% liposome-encapsulated 5-ALA spray with IPL reduced inflammatory facial acne in Asians, with a low risk of persistent phototoxic effects after PDT in this pilot study.

Split-face comparison study of cryogen spray cooling versus pneumatic skin flattening in skin tightening treatments using a long-pulsed Nd:YAG laser.

BACKGROUND: Nd:YAG pulsed lasers are used for non-ablative skin tightening treatment. A common drawback of this procedure is pain, which is often intolerable. Pneumatic skin flattening (PSF) is a new technology which alleviates pain in laser treatments. The purpose of this study is to assess the clinical efficacy and pain reduction in Nd:YAG laser skin tightening treatments with PSF compared to Nd:YAG laser skin tightening treatments with cryogen spray cooling (CSC). METHODS: Eleven patients were treated on the face with an Nd:YAG laser operated at an energy setting of 30 J/cm(2) and a pulse duration of 50 ms. Half of the face was treated with the Nd:YAG using CSC and the other side was treated with the Nd:YAG using PSF. A comparison of pain elicited from each treatment was done by comparing each patient's VAS pain scoring of the two sides. RESULTS: Treatment efficacy with CSC and with PSF was identical. The study confirmed significant pain reduction with PSF (p < 0.01). The average pain scores for PSF and CSC were 2.4 and 6.9, respectively. Mild ecchymosis was observed in two patients on the PSF side. CONCLUSION: Nd:YAG laser skin tightening treatments with PSF are less painful than Nd:YAG laser skin tightening treatments with CSC; the PSF treatments can be done with minimum side effects.

Prospective Comparison Study of 532/1064 nm Picosecond Laser vs 532/1064 nm Nanosecond Laser in the Treatment of Professional Tattoos in Asians.

BACKGROUND AND AIMS: Although, the pulse width should be shorter than the thermal relaxation time of the target, nanosecond laser pulses are not short enough for tattoo removal. Complications are common, such as hyper or hypopigmentation, textural changes, and scarring. Moreover, patients with darker skin types are at a higher risk of complications from tattoo removal using these lasers. Picosecond lasers were developed to overcome the limitation of nanosecond lasers. We did a comparison study of a 532/1064 nm picosecond laser vs a 532/1064 nm nanosecond laser to evaluate the clinical efficacy and complications of multi-color tattoos in Asians. MATERIALS AND METHODS: Eleven Asian patients with 37 professional tattoos were enrolled in the study. Each patient was treated with a 532/1064 nm nanosecond laser and a 532/1064 nm picosecond laser. The spot size that was used with each laser was 3 mm. Four treatments were performed, with four week intervals between each treatment. Patients were examined a week after the first treatment and 3 months after the last treatment. RESULTS AND CONCLUSIONS: All patients tolerated the treatments well. The efficacy of the 1064 nm picosecond laser for black tattoos is significantly better than the other studied lasers. The efficacy of the 532 nm picosecond laser is significantly better than the other studied lasers for red tattoos. The efficacy of the 532 nm picosecond laser is significantly better than the 532 nm nanosecond laser and better than the 1064 nm picosecond laser for green tattoos. Mild to moderate post-inflammatory hyperpigmentation was observed in 35.1%, 24.3% 27.0%, and 21.6% of the tattoos treated with the 532 nm nanosecond laser, the 532 nm picosecond laser, the 1064 nm nanosecond laser, and the 1064 nm pico-second laser, respectively. Paradoxical darkening (5.4%) was observed equally with each type of laser. There was no scar formation in any of the tattoos treated. The 532/1064 nm picosecond laser is more effective than the 532/1064 nm nanosecond laser in the treatment of multi-color tattoos in Asians. The 532 nm picosecond laser is more effective than 1064 nm picosecond laser in every tattoo color, with the exception of black. Paradoxical darkening was observed, even the use of picosecond lasers.

Combined use of pretest clinical probability score and latex agglutination D-dimer testing for excluding acute deep vein thrombosis.

OBJECTIVE: Currently, the latex agglutination D-dimer assay is widely used for excluding deep vein thrombosis (DVT) but is considered less sensitive than the enzyme-linked immunosorbent assay-based D-dimer test. The purpose of the present study was to determine if a combination of different cutoff points, rather than a single cutoff point of 1.0 microg/mL, on the latex agglutination D-dimer assay and the pretest clinical probability (PTP) score would be able to reduce the use of venous duplex ultrasound (DU) scanning in patients with suspected DVT. METHODS: The PTP score and D-dimer testing were used to evaluate 989 consecutive patients with suspected DVT before venous DU scanning. After calculating the clinical probability scores, patients were divided into low-risk (< or =0 points), moderate-risk (1-2 points), and high-risk (> or =3 points) pretest clinical probability groups. Receiver operating characteristic (ROC) curve analysis was used to determine the appropriate D-dimer cutoff point for each PTP with a negative predictive value of >98% for a positive DU scan. RESULTS: There were 886 patients enrolled. The study group included 609 inpatients (68.7%) and 277 outpatients (31.3%). The prevalence of DVT in this series was 28.9%. There were 508 patients (57.3%) classified as low-risk, 237 (26.8%) as moderate-risk, and 141 (14.9%) as high-risk PTP. DVT was identified in 29 patients (5.7%) with low-risk, 118 (49.8%) with moderate-risk, and 109 (77.3%) with high-risk PTP scores. ROC curve analysis was used to select D-dimer cutoff points of 2.6, 1.1, and 1.1 microg/mL for the low-, moderate- and high-risk PTP groups, respectively. In the low-risk PTP group, specificity increased from 48.9% to 78.2% (P < .0001) with use of the different D-dimer cutoff value. In the moderate- and high-risk PTP groups, however, the different D-dimer levels did not achieve substantial improvement. Despite this, the overall use of venous DU scanning could have been reduced by 43.0% (381 of 886) if the different D-dimer cutoff points had been used. CONCLUSIONS: Combination of a specific D-dimer level with the clinical probability score is most effective in low-risk PTP patients for excluding DVT. In moderate- and high-risk PTP patients, however, the recommended cutoff points of 1.0 microg/mL may be preferable. These results show that different D-dimer levels for patients differing in risk is feasible for excluding DVT using the latex agglutination D-dimer assay.

Treatment of traumatic scars using plasma skin regeneration (PSR) system.

OBJECTIVES: Several modalities have been advocated to treat traumatic scars, including surgical techniques and laser resurfacing. Recently, a plasma skin regeneration (PSR) system has been investigated. There are no reports on plasma treatment of traumatic scars. The objective of our study is to evaluate the effectiveness and complications of plasma treatment of traumatic scars in Asian patients. MATERIALS AND METHODS: Twenty Asian patients with traumatic scars were enrolled in the study. Three treatments were performed at monthly intervals with PSR, using energy settings of 2 to 3J. Patients were seen 1 week after each individual treatment and 3 months after the last treatment. Improvement was determined by patient questionnaires and physician evaluation of digital photographs taken prior to treatment and at 3 months post-treatment. The patients were also evaluated for any side effects from the treatment. RESULTS: Nine of 20 patients showed more than 50% improvement. The average pain score on a 10 point scale was 5.8+/-1.3 SD and all patients tolerated the treatments. The average re-epithelization time was 7.3+/-2.8 SD days. Temporary and local hyperpigmentation was observed in four patients and this hyperpigmentation disappeared within 3 months. Hypopigmentation and worsening of scarring were not observed. CONCLUSIONS: Plasma treatment is clinically effective and is associated with minimal complications when used to treat traumatic scars in Asian patients. However, deep traumatic scars are resistant to plasma treatment.

The use of focused ultrasound for non-invasive body contouring in Asians.

INTRODUCTION: Previous studies demonstrated that multiple treatments using focused ultrasound can be effective as an non-invasive method for reducing unwanted localized fat deposits. The objective of the study is to investigate the safety and efficacy of this focused ultrasound device in body contouring in Asians. METHOD: Fifty-three (51 females and 2 males) patients were enrolled into the study. Subjects had up to three treatment sessions with approximately 1-month interval in between treatment. Efficacy was assessed by changes in abdominal circumference, ultrasound fat thickness, and caliper fat thickness. Weight change was monitored to distinguish weight loss induced changes in these measurements. Patient questionnaire was completed after each treatment. The level of pain or discomfort, improvement in body contour and overall satisfaction were graded with a score of 1-5 (1 being the least). Any adverse effects such as erythema, pain during treatment or blistering were recorded. RESULT: The overall satisfaction amongst subjects was poor. Objective measurements by ultrasound, abdominal circumference, and caliper did not show significant difference after treatment. There is a negative correlation between the abdominal fat thickness and number of shots per treatment session. CONCLUSION: Focused ultrasound is not effective for non-invasive body contouring among Southern Asians as compared with Caucasian. Such observation is likely due to smaller body figures. Design modifications can overcome this problem and in doing so, improve clinical outcome.