Influence of tissue desiccation on critical temperature for thermal damage during Er:YAG laser skin treatments.

OBJECTIVES: Erbium lasers have become an accepted tool for performing both ablative and non-ablative medical procedures, especially when minimal invasiveness is desired. Hard-tissue desiccation during Er:YAG laser procedures is a well-known phenomenon in dentistry, the effect of which is to a certain degree being addressed by the accompanying cooling water spray. The desiccation of soft tissue has attracted much less attention due to the soft tissue's high-water content, resulting in a smaller effect on the ablation process. MATERIALS AND METHODS: In this study, the characteristics of skin temperature decay following irradiations with Er:YAG laser pulses were measured using a fast thermal camera. RESULTS: The measurements revealed a substantial increase in temperature decay times and resulting thermal exposure times following irradiations with Er:YAG pulses with fluences below the laser ablation threshold. Based on an analytical model where the skin surface cooling time is calculated from the estimated thickness of the heated superficial layer of the stratum corneum (SC), the observed phenomena is attributed to the accelerated evaporation of water from the SC's surface. By using an Arrhenius damage integral-based variable heat shock model to describe the dependence of the critical temperature on the duration of thermal exposure, it is shown that contrary to what an inexperienced practitioner might expect, the low-to-medium level fluences may result in a larger thermal damage in comparison to treatments where higher fluences are used. This effect may be alleviated by hydrating the skin before Er:YAG treatments. CONCLUSION: Our study indicates that tissue desiccation may play a more important role than expected for soft-tissue procedures. It is proposed that its effect may be alleviated by hydrating the skin before Er:YAG treatments.

FOVELASS: A Randomised Trial of Endovenous Laser Ablation Versus Polidocanol Foam for Small Saphenous Vein Incompetence.

OBJECTIVE: To compare the outcomes of ultrasound guided foam sclerotherapy (UGFS) and endovenous laser ablation (EVLA) to treat isolated small saphenous vein (SSV) incompetence in a multicentre randomised controlled study (RCT; ClinicalTrials.gov identifier: NCT05468450). METHODS: Patients aged ≥ 18 years undergoing isolated SSV treatment (reflux > 0.5 seconds) were randomised to UGFS or EVLA. Patients treated with UGFS were allowed one additional truncal treatment at six weeks. Tributary treatments (phlebectomy or sclerotherapy) were permitted after six months. Participants were assessed at eight days, six months, and one, two, and three years. The primary endpoint was the absence of SSV reflux (> 0.5 seconds). Secondary outcomes included clinical scores and quality of life (QoL) scores. All analyses were done by intention to treat. RESULTS: Of 1 522 screened patients, 161 were randomised to UGFS (n = 82) and EVLA (n = 79). Only 3% of patients who received UGFS had the second (allowed) treatment and 86% of patients completed the three year study. Forty-one and 19 tributary treatments (by sclerotherapy) were performed in 27 UGFS patients (33%) and 15 EVLA patients (19%), respectively. The complete absence of reflux at three years was significantly better after EVLA (86%) than after UGFS (56%) (odds ratio [OR] 5.36, 95% confidence interval [CI] 2.31 - 12.44; risk ratio 1.59, 95% CI 1.26 - 2.01). Two deep vein thromboses (DVTs; one femoropopliteal and one gastrocnemius) and one endovenous heat induced thrombosis occurred in the EVLA group. Seven DVTs were seen in the UGFS group, including two partial popliteal DVTs and five gastrocnemius vein thromboses (four asymptomatic and incidental on day 8 screening). At three years, there was no difference between groups for the following: rate of visible varices (p = .87), revised Venous Clinical Severity Score (p = .28), and QoL (p = .59). Patient satisfaction scores were high in both groups (median score: EVLA 97/100 and UGFS 93/100; p = .080). Symptoms were significantly improved in both groups. (p < .001) CONCLUSION: Technical success was better for EVLA than for UGFS three years after SSV treatment. This agrees with studies that have reported on these treatments in the great saphenous vein. However, improvements in clinical outcome were similar for both groups.

Results of Excimer Laser Ablation Combined with Drug-Coated Balloon for Atherosclerotic Obliterans of Lower Extremity and Risk Factors for Loss of Primary Patency.

BACKGROUND: The results of excimer laser ablation (ELA) combining with drug-coated balloon (DCB) in the treatment for atherosclerotic obliterans (ASO) remains unclear. METHODS: Retrospectively enrolled patients who underwent ELA combined with DCB in 2 centers. The primary endpoint was primary patency, and secondary endpoints included technical success, procedure-related complications, major amputation, clinically driven target lesions reintervention (CD-TLR), measurements of ankle-brachial index (ABI), and quality of life (QoL). RESULTS: 102 patients were enrolled. The primary patency was 86.7% (95% confidence interval [CI]: 72.9%-89.0%) at 12 months and 82.6% (95% CI: 78.2%-92.1%) at 24 months. The freedom from reintervention was 87.8% (95% CI: 79.5%-92.9%) at 12 months and 86.6% (95% CI: 78.1%-92.0%) at 24 months. The ABI measurement and QoL were significantly improved at each follow-up point. Sixteen (15.7%) patients lost the primary patency. Patients losing the primary patency demonstrated higher Rutherford class (P = 0.004), worse runoff (P < 0.001), higher Peripheral Arterial Calcium Scoring System (PACSS) (P < 0.001), and smaller ratio of tube diameter to reference vessel diameter (TD/RVD) (P < 0.001) compared with patients without losing it. The run-off ≥7 (adjusted odds ratio [aOR]: 34.3; 95% CI: 2.9-398.3; P = 0.005) and TD/RVD <4.9 (aOR: 24.7; 95% CI: 1.7-359.5; P = 0.019) were independent risk factors for loss of primary patency. CONCLUSIONS: ELA combined with DCB seemed an effective and safe treatment for ASO of lower extremity, and it could not only reduce the implantation of stent but significantly improve QoL. The run-off ≥7 and TD/RVD <4.9 were independent risk factors for loss of primary patency.

Evaluation of cutting efficiency and thermal damage during soft tissue surgery with 940 nm-diode laser: An ex vivo study.

OBJECTIVES: To investigate quantitatively the cutting efficiency and the thermal effects in the surrounding soft tissues of incisions that are induced by a 940 nm-diode laser with different power settings. MATERIALS AND METHODS: Fifty-four gingival samples were prepared from the lower jaws of freshly slaughtered German-land race pigs and were randomly divided into 9 groups (n = 6) according to the adjusted output power (1, 1.5, 2, 2.5, 3, 3.5, 4, 5 and 6 W). Five incisions were implemented for each sample using a diode laser (940 nm) in continuous wave with an initiated tip resulting in 30 incisions for each experimental group utilizing a three-dimensional computer-controlled micropositioner. The samples were prepared for histometric evaluation using a transmitted light microscope. The cutting depth and width and the thermal damage were recorded for each sample and the efficiency factor γ was calculated. RESULTS: The highest cutting efficiency (γz = 0.81 ± 0.03) exhibited the group with 5 W output power (p < 0.05), while the lowest (γz = 0.45 ± 0.11) showed the 1-W group (p < 0.05). Over 3.5 W there was a rapid increase in the size of thermal damage of the incisions, especially for 6 W, which presented the largest. CONCLUSIONS: The most effective power parameters of diode laser (940 nm) for soft tissue surgery were from 3 to 5 W. The outcomes of the current study may help to establish clinical protocols for the use of diode lasers (940 nm) in soft tissue surgery in contact mode assisting dental professionals to achieve optimal clinical results and avoid complications.

Incidence and Clinical Impact of Endovenous Glue-Induced Hypersensitivity Among Patients Who Underwent Endovenous Cyanoacrylate Ablation Procedures: A Registry-Based Cohort Study.

BACKGROUND: The characteristics of endovenous glue-induced hypersensitivity (EGIH) remain unclear. OBJECTIVE: To assess the clinical impacts on patients with EGIH after endovenous cyanoacrylate-glue ablation (CA). MATERIALS AND METHODS: A prospectively designed endovenous CA-specific registry was created, and a total of 335 limbs from 173 patients who underwent endovenous CA were enrolled for a cohort study. RESULTS: Symptomatic EGIH was observed in 55 (31.8%) patients. Beyond the target vein area, systemic side effects were noted in 5.8% of the treated patients after CA. The median onset time was 13 postoperative days (range: 1-35 days). The median duration was 7 days, but about 10.9% of the affected patients experienced symptoms lasting longer than 4 weeks. In the EGIH and non-EGIH groups, significant improvements in venous clinical severity score and Chronic Venous Insufficiency Quality of Life Questionnaire-14 scores were observed 3 months postoperatively. The development of EGIH did not affect the postoperative patient-reported satisfaction scores ( p = .524). CONCLUSION: EGIH is observed in a substantial proportion of patients. The side effects do not affect the clinical outcomes and patient-reported outcome measures. Further studies are required on the detailed pathogenesis and definition of EGIH.

Nd:YAG laser therapy on postoperative pain, swelling, and trismus after mandibular third molar surgery: a randomized double-blinded clinical study.

This study aims to evaluate the effect of Nd:YAG laser therapy (NdLT) on postoperative pain, swelling, and trismus after mandibular third molar (M3) surgery. Three hundred patients were randomly divided into the Nd group (n = 100), medication group (n = 100), and Nd+medication (Nd+m) group (n = 100). The WHARFE classification system was used to assess surgical difficulty. After surgery, the Nd group was irradiated by the Nd:YAG laser in very long-pulsed mode (VLP, pulse duration 1 ms, 20 Hz, 4 W, R21-C3) in 6 regions of the extraction socket with a total energy of 300 J. For the medication group, dexamethasone 0.75 mg and loxoprofen 60 mg were prescribed immediately and every 12 h thereafter for 3 days. The Nd+m group received both treatments mentioned above. Pain assessment was performed at 6, 24, 48, and 72 h postoperatively using the visual analog scale (VAS). Swelling was evaluated by changes in the distance from (1) the tragus to the labial commissure, (2) the tragus to the pogonion, and (3) the mandibular angle to the lateral canthus preoperatively and 72 h postoperatively. Trismus was assessed by the change in maximum mouth opening. Groups Nd and Nd+m had lower VAS scores at 6 h, 24 h, and 48 h (F = 13.80, p = 0.00), but the difference between the two groups was not significant (F = 1.34, p = 0.11). However, no significant difference was observed at 72 h (p = 0.10). There was no significant difference in swelling or trismus among the three groups (p > 0.05). NdLT is an effective approach to improve complications after M3 surgery.

Ablation-cooled material removal with ultrafast bursts of pulses.

The use of femtosecond laser pulses allows precise and thermal-damage-free removal of material (ablation) with wide-ranging scientific, medical and industrial applications. However, its potential is limited by the low speeds at which material can be removed and the complexity of the associated laser technology. The complexity of the laser design arises from the need to overcome the high pulse energy threshold for efficient ablation. However, the use of more powerful lasers to increase the ablation rate results in unwanted effects such as shielding, saturation and collateral damage from heat accumulation at higher laser powers. Here we circumvent this limitation by exploiting ablation cooling, in analogy to a technique routinely used in aerospace engineering. We apply ultrafast successions (bursts) of laser pulses to ablate the target material before the residual heat deposited by previous pulses diffuses away from the processing region. Proof-of-principle experiments on various substrates demonstrate that extremely high repetition rates, which make ablation cooling possible, reduce the laser pulse energies needed for ablation and increase the efficiency of the removal process by an order of magnitude over previously used laser parameters. We also demonstrate the removal of brain tissue at two cubic millimetres per minute and dentine at three cubic millimetres per minute without any thermal damage to the bulk.

Laser therapy for treating hypertrophic and keloid scars.

BACKGROUND: Hypertrophic and keloid scars are common skin conditions resulting from abnormal wound healing. They can cause itching, pain and have a negative physical and psychological impact on patients' lives. Different approaches are used aiming to improve these scars, including intralesional corticosteroids, surgery and more recently, laser therapy. Since laser therapy is expensive and may have adverse effects, it is critical to evaluate the potential benefits and harms of this therapy for treating hypertrophic and keloid scars. OBJECTIVES: To assess the effects of laser therapy for treating hypertrophic and keloid scars. SEARCH METHODS: In March 2021 we searched the Cochrane Wounds Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL EBSCO Plus and LILACS. To identify additional studies, we also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports. There were no restrictions with respect to language, date of publication, or study setting. SELECTION CRITERIA: We included randomised controlled trials (RCTs) for treating hypertrophic or keloid scars (or both), comparing laser therapy with placebo, no intervention or another intervention. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, extracted the data, assessed the risk of bias of included studies and carried out GRADE assessments to assess the certainty of evidence. A third review author arbitrated if there were disagreements. MAIN RESULTS: We included 15 RCTs, involving 604 participants (children and adults) with study sample sizes ranging from 10 to 120 participants (mean 40.27). Where studies randomised different parts of the same scar, each scar segment was the unit of analysis (906 scar segments). The length of participant follow-up varied from 12 weeks to 12 months. All included trials had a high risk of bias for at least one domain: all studies were deemed at high risk of bias due to lack of blinding of participants and personnel. The variability of intervention types, controls, follow-up periods and limitations with report data meant we pooled data for one comparison (and only two outcomes within this). Several review secondary outcomes - cosmesis, tolerance, preference for different modes of treatment, adherence, and change in quality of life - were not reported in any of the included studies. Laser versus no treatment: We found low-certainty evidence suggesting there may be more hypertrophic and keloid scar improvement (that is scars are less severe) in 585-nm pulsed-dye laser (PDL) -treated scars compared with no treatment (risk ratio (RR) 1.96; 95% confidence interval (CI): 1.11 to 3.45; two studies, 60 scar segments). It is unclear whether non-ablative fractional laser (NAFL) impacts on hypertrophic scar severity when compared with no treatment (very low-certainty evidence). It is unclear whether fractional carbon dioxide (CO2) laser impacts on hypertrophic and keloid scar severity compared with no treatment (very low-certainty evidence). Eight studies reported treatment-related adverse effects but did not provide enough data for further analyses. Laser versus other treatments: We are uncertain whether treatment with 585-nm PDL impacts on hypertrophic and keloid scar severity compared with intralesional corticosteroid triamcinolone acetonide (TAC), intralesional Fluorouracil (5-FU) or combined use of TAC plus 5-FU (very low-certainty evidence). It is also uncertain whether erbium laser impacts on hypertrophic scar severity when compared with TAC (very low-certainty evidence). Other comparisons included 585-nm PDL versus silicone gel sheeting, fractional CO2 laser versus TAC and fractional CO2 laser versus verapamil. However, the authors did not report enough data regarding the severity of scars to compare the interventions. As only very low-certainty evidence is available on treatment-related adverse effects, including pain, charring (skin burning so that the surface becomes blackened), telangiectasia (a condition in which tiny blood vessels cause thread-like red lines on the skin), skin atrophy (skin thinning), purpuric discolorations, hypopigmentation (skin colour becomes lighter), and erosion (loss of part of the top layer of skin, leaving a denuded surface) secondary to blistering, we are not able to draw conclusions as to how these treatments compare. Laser plus other treatment versus other treatment: It is unclear whether 585-nm PDL plus TAC plus 5-FU leads to a higher percentage of good to excellent improvement in hypertrophic and keloid scar severity compared with TAC plus 5-FU, as the certainty of evidence has been assessed as very low. Due to very low-certainty evidence, it is also uncertain whether CO2 laser plus TAC impacts on keloid scar severity compared with cryosurgery plus TAC. The evidence is also very uncertain about the effect of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser plus intralesional corticosteroid diprospan plus 5-FU on scar severity compared with diprospan plus 5-FU and about the effect of helium-neon (He-Ne) laser plus decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream on scar severity compared with decamethyltetrasiloxane, polydimethylsiloxane and cyclopentasiloxane cream. Only very low-certainty evidence is available on treatment-related adverse effects, including pain, atrophy, erythema, telangiectasia, hypopigmentation, regrowth, hyperpigmentation (skin colour becomes darker), and depigmentation (loss of colour from the skin). Therefore, we are not able to draw conclusions as to how these treatments compare.  AUTHORS' CONCLUSIONS: There is insufficient evidence to support or refute the effectiveness of laser therapy for treating hypertrophic and keloid scars. The available information is also insufficient to perform a more accurate analysis on treatment-related adverse effects related to laser therapy. Due to the heterogeneity of the studies, conflicting results, study design issues and small sample sizes, further high-quality trials, with validated scales and core outcome sets should be developed. These trials should take into consideration the consumers' opinion and values, the need for long-term follow-up and the necessity of reporting the rate of recurrence of scars to determine whether lasers may achieve superior results when compared with other therapies for treating hypertrophic and keloid scars.

Cyanoacrylate Embolization versus Endovenous Laser Ablation in Treating Saphenous Vein Insufficiency: A Systematic Review and Meta-Analysis.

INTRODUCTION: Cyanoacrylate embolization (CAE) is a novel non-thermal non-tumescent venous ablation technique that has shown promising results in treating saphenous vein insufficiency. We aimed to assess the efficacy and safety profile of CAE in comparison to endovenous laser ablation (EVLA) in treating saphenous vein insufficiency. MATERIAL AND METHODS: We conducted a systematic review and meta-analysis in accordance with the PRISMA Statement. A systematic search was performed through online databases including PubMed, ScienceDirect, and Cochrane to find relevant studies. Manual searching was also performed from the references of the selected studies. Specific keywords that we used were "(cyanoacrylate) AND (laser OR laser ablation OR laser therapy) AND (vein OR venous OR saphenous vein OR venous insufficiency OR varicose vein)". Outcomes of interest were efficacy, safety, and intervention time. Efficacy was determined by venous closure rate 1 year post-intervention and Venous Clinical Severity Score (VCSS) 1 year post-intervention. Safety was determined by rates of periprocedural pain, skin pigmentation, nerve damage, phlebitis, deep vein thrombosis (DVT) and ecchymosis. Data extraction and quality assessment of included studies were performed by 2 reviewers, and statistical analysis was conducted using RevMan 5.4.0 software. RESULTS: Five relevant articles (2 randomized-controlled trials and 3 cohort studies) were selected for this study, consisting a total of 1432 venous ablation procedures (710 CAE and 722 EVLA). From the efficacy point of view, venous closure rates and VCSS did not differ significantly between CAE group and EVLA group. From the safety point of view, pooled data showed that CAE group was associated with less periprocedural pain score (P < 0.001), lower skin pigmentation rates (0.60% vs. 4.46%; P = 0.008), and lower nerve damage rates (0% vs. 3.94%; P = 0.007). Rates of phlebitis, deep vein thrombosis, and ecchymosis did not differ significantly between the 2 groups. In addition, intervention time was significantly faster in CAE group compared to EVLA group (P < 0.001). CONCLUSION: Cyanoacrylate embolization yields similar efficacy compared to EVLA. However, CAE is associated with less periprocedural pain, lower occurrence rates of skin pigmentation and nerve damage, and faster intervention time.

A Contemporary Comparison of Cyanoacrylate, Radiofrequency, and Endovenous Laser Ablation on Healing of Active Venous Ulceration.

BACKGROUND: The goal of this study is to compare the healing rates of active lower extremity venous ulcers for patients receiving one of 3 ablation methods, compare their complications, and identify factors affecting successful healing and prevention of recurrence. METHODS: For this study, data were collected retrospectively on 146 patients at a single institution, tertiary referral center, with an active venous ulcer who underwent ablation therapy via cyanoacrylate (VenaSeal), radiofrequency (RFA), or endovenous laser ablation (EVLA) from 2010 to 2020. RESULTS: The study showed a nonsignificant difference in days to ulcer healing postintervention between ablative techniques, with 80.8 days for cyanoacrylate ablation (n = 15), 70.07 for RFA (n = 44), and 67.04 days for EVLA (n = 79). A similar, nonsignificant trend was observed for ulcer recurrence, with a rate of 35.7% (5/14) for cyanoacrylate ablation, 26.7% (20/75) for EVLA, and 23.1% (9/39) for RFA. The same nonsignificant trend occurred with deep venous thrombosis following the procedure in 6.3% (1/16) of cyanoacrylate ablation, 4.8% (4/84) of EVLA, and 2.2% (1/46) of RFA cases. The rate of endovenous glue induced thrombosis was also higher (6.3%) for cyanoacrylate than endovenous heat induced thrombosis in EVLA (3.6%) and RFA (2.2%). Cox proportional hazard was significant for compliance with compression therapy (hazard ratio [HR] 2.12, confidence interval [CI] 95% = 1.10-4.20, P = 0.031) and a lack of working with a wound clinic (HR 0.50, CI 95% = 0.33-0.75, P = 0.001) were associated with the decreased time to healing of ulcer but was not influenced by the presence of other comorbidities of smoking or diabetes mellitus. CONCLUSIONS: This study indicates a trend toward cyanoacrylate ablation having longer healing times and more complications compared to other ablation methods when used in patients with active venous ulcers. Compliance with compression treatment is predictive of venous ulcer healing and working with a wound clinic had significantly longer healing times.

Evaluating impact of Nd: YAG laser associated defects on optical quality of hydrophilic and hydrophobic intraocular lenses using visualization of light propagation and USAF test targets.

BACKGROUND: Neodymium:yttrium aluminum garnet (Nd:YAG) laser capsulotomy is a well-accepted, safe, and effective measure in the treatment of posterior capsule opacification. However, iatrogenic intraocular lens damage is a relatively common side effect that happens due to inappropriate focusing during the procedure. This experimental study analyzes the impact of YAG-pits to obtain qualitative information. METHODS: Acrylic, monofocal hydrophilic and hydrophobic intraocular lenses (IOLs) with 6.0 mm optic and the with the same power (21D) were studied. First, all measurements were done with unmodified IOLs. Damage was intentionally created, performing YAG-pits (n = 5) in the central area of the lens optic (3.0 mm) using a photodisruption laser with the same energy level of 1.8 mJ. To simulate the cruciate pattern, the 5 defects were created in a cross shape within the 3.0 mm optical zone. Afterwards, all laboratory measurements were repeated: These included the United States Air Force (USAF) resolution test chart to study the imaging performance of the IOL, light field measurements to show the course of the rays behind the IOL and the modulation transfer function (MTF) measurements were analyzed. RESULTS: Evaluating USAF showed that unmodified lenses produced a sharper image. Damaged lenses led to a more blurred image and to the impression of a lower contrast with a kind of halo/glare effect. The light field measurement showed that YAG-pits led to a kind of dispersion and scattering effect, which was higher in hydrophobic IOLs. MTF showed a deterioration in damaged hydrophilic and hydrophobic IOLs, respectively. CONCLUSION: Our experimental study confirms that YAG-pits can reduce imaging quality of intraocular lenses. These defects behave as a new Huygens source, distribute a spherical wave that additionally illuminate the background of the USAF target. It can be assumed that material properties of the IOL (water content, refractive index) play an important role and affect results. The impact level is strongly dependent on the number, size and position of YAG-pits within the optic. LIMITATION: Only monofocal IOLs have been investigated so far, further tests with various IOL optics have to follow. In addition, simulating the circular pattern of YAG capsulotomy is necessary.

Feasibility and safety of THRIVE in transoral laser microsurgery.

OBJECTIVE: Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) presents obvious advantage in laryngeal surgery and Transoral Laser Microsurgery (TLM). Airway fire represents a rare complication of TLM and may be the most important limitation in the use of THRIVE. The objective was to evaluate the different operating conditions of the TLM with THRIVE with regard to fire risk. EXPERIMENT: In this report, we assessed the risk of fire by varying the Fraction of Inspired Oxygen (FiO2), the Laser Energy, and the placement of endolaryngeal surgical and ventilatory equipment in a porcine model for TLM. RESULTS: Fire, sparks and smoke were reported. No combustion occurred with THRIVE in the absence of an endolaryngeal material. Fire occurred systematically while delivering between 3 and 5 W Carbon dioxide (CO2) Laser direct shot on a dry laryngeal cotton. Conclusion THRIVE-TLM should never be performed using a dry cotton or a plastic endolaryngeal material.

Evaluation of efficacy and safety of chemical peeling and long-pulse Nd:YAG laser in treatment of pseudofolliculitis barbae.

Pseudofolliculitis barbae (PFB) presents as chronic inflammation of the beard area that affect males but also females may affect if have coarse hair. Its treatment can be challenging. Laser-assisted hair removal causes miniaturization of hair shafts which are the principal contributors to inflammation in PFB. Also chemical peeling is used in treatment of PFB. To assess and compare the efficacy and safety of long pulsed Nd:YAG laser vs chemical peeling in the treatment of PFB. Twenty male patients with PFB were divided randomly into two groups. Group A treated by long pulsed Nd: Yag laser and group B treated by chemical peeling, all were subjected to treatment until complete clearance or maximum five sessions. Clinical assessment of skin lesions was done at baseline, end of sessions, follow-up at 3 months after end of therapy by counting of papules. Subjective evaluations were also obtained from both subjects and investigators. Assessments of any abnormal side effects caused by laser treatment or by chemical peeling were also evaluated. A reduction in the quantity of papules/pustules when compared with baseline data was statistically significant more in laser group than peeling group for treatment of PFB in the mandibular and neck regions at the end of session and follow-up evaluations. Subject evaluations ranged from satisfied to very satisfied. Side effects of chemical peeling included transient hyperpigmentation, mild erythema, and burning and side effects of laser included pain. Both therapy are effective and safe in the treatment of PFB but laser therapy more effective than peeling therapy.

Laser therapy for dentinal hypersensitivity.

BACKGROUND: Dentinal hypersensitivity is characterized by short, sharp pain from exposed dentine that occurs in response to external stimuli such as cold, heat, osmotic, tactile or chemicals, and cannot be explained by any other form of dental defect or pathology. Laser therapy has become a commonly used intervention and might be effective for dentinal hypersensitivity. OBJECTIVES: To assess the effects of in-office employed lasers versus placebo laser, placebo agents or no treatment for relieving pain of dentinal hypersensitivity. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 20 October 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library 2020, Issue 9), MEDLINE Ovid (1946 to 20 October 2020), Embase Ovid (1980 to 20 October 2020), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; 1937 to 20 October 2020), and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; from 1982 to 20 October 2020). Conference proceedings were searched via the ISI Web of Science and ZETOC, and OpenGrey was searched for grey literature. The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: Randomized controlled trials (RCTs) in which in-office lasers were compared to placebo or no treatment on patients aged above 12 years with tooth hypersensitivity. DATA COLLECTION AND ANALYSIS: Two review authors independently and in duplicate screened the search results, extracted data, and assessed the risk of bias of the included studies. Disagreement was resolved by discussion. For continuous outcomes, we used mean differences (MD) and 95% confidence intervals (CI). We conducted meta-analyses only with studies of similar comparisons reporting the same outcome measures. We assessed the overall certainty of the evidence using GRADE. MAIN RESULTS: We included a total of 23 studies with 936 participants and 2296 teeth. We assessed five studies at overall low risk of bias, 13 at unclear, and five at high risk of bias. 17 studies contributed data to the meta-analyses. We divided the studies into six subgroups based on the type of laser and the primary outcome measure. We assessed the change in intensity of pain using quantitative pain scale (visual analogue scale (VAS) of 0 to 10 (no pain to worst possible pain)) when tested through air blast and tactile stimuli in three categories of short (0 to 24 hours), medium (more than 24 hours to 2 months), and long term (more than 2 months). Results demonstrated that compared to placebo or no treatment the application of all types of lasers combined may reduce pain intensity when tested through air blast stimuli at short term (MD -2.24, 95% CI -3.55 to -0.93; P = 0.0008; 13 studies, 978 teeth; low-certainty evidence), medium term (MD -2.46, 95% CI -3.57 to -1.35; P < 0.0001; 11 studies, 1007 teeth; very low-certainty evidence), and long term (MD -2.60, 95% CI -4.47 to -0.73; P = 0.006; 5 studies, 564 teeth; very low-certainty evidence). Similarly, compared to placebo or no treatment the application of all types of lasers combined may reduce pain intensity when tested through tactile stimuli at short term (MD -0.67, 95% CI -1.31 to -0.03; P = 0.04; 8 studies, 506 teeth; low-certainty evidence) and medium term (MD -1.73, 95% CI -3.17 to -0.30; P = 0.02; 9 studies, 591 teeth; very low-certainty evidence). However, there was insufficient evidence of a difference in pain intensity for all types of lasers when tested through tactile stimuli in the long term (MD -3.52, 95% CI -10.37 to 3.33; P = 0.31; 2 studies, 184 teeth; very low-certainty evidence). Most included studies assessed adverse events and reported that no obvious adverse events were observed during the trials. No studies investigated the impact of laser treatment on participants' quality of life. AUTHORS' CONCLUSIONS: Limited and uncertain evidence from meta-analyses suggests that the application of laser overall may improve pain intensity when tested through air blast or tactile stimuli at short, medium, or long term when compared to placebo/no treatment. Overall, laser therapy appears to be safe. Future studies including well-designed double-blinded RCTs are necessary to further investigate the clinical efficacy of lasers as well as their cost-effectiveness.

Laser atherectomy and drug-coated balloons for the treatment of femoropopliteal in-stent restenosis: 2-Year outcomes.

BACKGROUND: Femoropopliteal (FP) artery is one of the most anatomically challenging areas for sustained stent patency. The incidence of FP in-stent restenosis (ISR) is estimated at 50% at 24 months. Prior studies have shown that lesion debulking with laser atherectomy (LA) combined with drug coated balloon (DCB) have superior outcomes compared to LA + balloon angioplasty (BA) ISR, but there have not been studies evaluating 2-year outcomes. METHODS: This was a dual-center retrospective cohort study that compared patients with FP-ISR treated with LA + DCB versus LA + BA. Cox regression analysis was used to examine 2-year outcomes of target lesion revascularization (TLR) and the composite outcome of TLR or restenosis. Multivariable analysis was performed for clinical and statistically significant (in the univariate analysis) variables. RESULTS: One hundred and seventeen consecutive patients with Tosaka II (n = 32) and III (n = 85) ISR were analyzed. Sixty-six patients were treated with LA + DCB and 51 with LA + BA. The LA + DCB group had more lesions with moderate to severe calcification (58% vs. 13%; p < .0001). The LA + DCB group was more likely to be treated with the use of embolic protection devices (64% vs. 23%, p < .001) and cutting balloons (61% vs. 6%, p < .001). Bail-out stenting rates were lower in the LA + DCB group (32% vs. 57%, p = .008). LA + DCB was superior (HR: 0.57; 95% CI: 0.34-0.9, p = .027) for the composite outcome of 2-year TLR or restenosis. The 12-month KM estimates for freedom from TLR or restenosis were 66% in the LA + DCB group versus 46% in the LA + BA group. The 24-month KM estimates were 45% in the LA + DCB group versus 24% in the LA + BA group. CONCLUSIONS: The combination of DCB + LA was associated with decreased rates of bail-out stenting and improved 2-year TLR or restenosis rates. Randomized clinical trials examining the DCB + LA combination for FP-ISR are needed.

Wound Healing Treatments After Ablative Laser Skin Resurfacing: A Review.

Laser resurfacing has progressed since the 1980s to treat a variety of medical and aesthetic indications with ever-evolving safety parameters. While laser technology has evolved to provide a more favorable safety profile and decrease wound healing time, advances in post-procedure healing agents have also helped to mitigate adverse effects, such as persistent erythema, dyspigmentation, acneiform eruptions, dermatitis, infections, and scarring. We reviewed the evidence of growth factors, stem cells, silicone and silicone polymers, botanical based treatments, fatty acids, probiotics, and closed dressings on post-ablative laser skin resurfacing. All reviewed agents demonstrated some evidence in improving post-procedure outcomes, albeit mixed in many cases. Additionally, these studies contain small numbers of participants, vary in type, strength, and clinical indication for which the resurfacing laser was used, and have differing postprocedural evaluation protocols and assessments. This highlights a need for standardization of clinical studies and the importance of choosing an optimal postprocedural skincare plan depending on every unique clinical scenario. J Drugs Dermatol. 2020;19(11):1050-1055. doi:10.36849/JDD.2020.5386.

Polymethylmethacrylate-induced nodules of the lips: Clinical presentation and management by intralesional neodymium:YAG laser therapy.

The lips are essential part of the beauty and attractiveness of the human face. Lip augmentation has become an increasingly used method to improve appearance. Soft tissue fillers are the most commonly used tools. Permanent fillers, however, have been associated with unwanted side effects after lip augmentation. In the present article the present authors will focus on permanent fillers based on polymethylmethacrylate (PMMA). The present authors provide a short review on PMMA fillers and known associated adverse events. The present authors provide a critical review of treatment options. Illustrated by clinical cases The present authors report our preferred treatment of PMMA nodules on lips by intralesional neodymium:YAG laser and blunt suction cannula with or without minor surgery.

Periocular CO2 laser resurfacing: severe ocular complications from multiple unintentional laser impacts on the protective metal eye shields.

BACKGROUND AND OBJECTIVES: A 36-year-old woman underwent CO2 laser resurfacing for periocular rhytides using protective stainless steel Cox II ocular shields. Immediately after the treatment, corneal lesions were seen in both eyes. The left eye subsequent developed corneal ulceration and scarring, a deformed iris, cataract, and lower eye lashes showing signs of acute burns. The right cornea had a small inferior mid-peripheral superficial lesion and concomitant lower mid-peripheral burned eye lashes. Our objective was to determine the most likely cause of these ocular complications. STUDY: We estimated temperature-time combinations that could induce corneal injury and cataract. Heat conduction effects from a heated cornea to the lens and from a heated ring of periocular skin to the cornea were computed. The temperature response of a shield following CO2 laser irradiation was determined. RESULTS: We computed that cataract can develop when the corneal temperature reaches, for example, 80 °C for 14 seconds. A periocular ring of heated skin contributes little to the corneal temperature. After 7 pulses of consecutive CO2 laser bursts in 7.5 seconds, the total shield area already reached a homogeneous temperature of 63 °C. CONCLUSION: Despite uncertainties in procedural details and modeling of cataract temperatures, the eye injuries were caused beyond doubt by heating of tear-covered metal eye shields by at least 10 consecutive but unintentional laser impacts. Lasers Surg. Med. 50:980-986, 2018. © 2018 Wiley Periodicals, Inc.

Gingival melanin depigmentation by Er:YAG laser: A literature review.

Laser ablation is recently suggested as a most effective and reliable technique for depigmentation of melanin hyperpigmented gingiva. To date, different lasers have been used for gingival depigmentation (CO2, diode, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers). The use of Er:YAG laser for depigmentation of melanin hyperpigmented gingiva has gained increasing importance in recent years. The purpose of this study was to report removal of gingival melanin pigmentation using an Er:YAG laser in a literature review. The main outcomes, such as improvement of signs (clinical parameters of bleeding, erythema, swelling and wound healing), symptoms (pain) and melanin recurrence/repigmentation were measured. The literature demonstrated that depigmentation of gingival melanin pigmentation can be performed safely and effectively by Er:YAG laser resulting in healing and an esthetically significant improvement of gingival discoloration. Thus, Er:YAG laser seems to be safe and useful in melanin depigmentation procedure. However, the main issue in giving the final conclusion of the optimal Er:YAG laser use in melanin depigmentation is that, to date, studies are offering completely discrepant Er:YAG laser procedure protocols (complex settings of laser parameters), and different criteria for the assessment of depigmentation and repigmentation (recurrence), thus hampering the comparison of the results. Therefore, further studies are necessary to give an optimal recommendation on the use of Er:YAG laser in gingival melanin hyperpigmentation.

Outcomes and costs associated with two different lead-extraction approaches: a single-centre study.

AIMS: We sought to compare outcomes and costs of a stepwise approach to transvenous lead extraction (TLE) involving laser-assisted sheaths or mechanical polypropylene sheaths, with/without crossover. METHODS AND RESULTS: We prospectively included patients who underwent TLE (between August 2013 and December 2014) as part of a stepwise approach involving simple traction, lead snaring, and sheath-assisted dissection; all of these patients underwent a first-line polypropylene-sheath-extraction approach (Group A). The comparison group (Group B) was consecutive patients who had undergone TLE before August 2013, during which laser-assisted sheath extraction was the first-line approach. The number of patients in Group B was adjusted to match the number who eventually needed sheaths in Group A. Procedural data, outcomes, and costs were compared between groups (comparison of approaches) and in patients who needed sheath-assisted extraction (comparison of techniques). Overall, 521 leads were extracted (131 patients in Group A, 104 in Group B). Radiological and clinical success rates were similar; crossover from polypropylene to laser sheaths was needed in 10 patients in Group A (vs. none in Group B). Radiological (P< 0.001) and clinical (P= 0.01) success rates were higher and were achieved with a lower radiation exposure (P= 0.03) with laser sheaths in patients (60 in each group) who needed sheath-assisted extraction. Complication rates were similar in both groups (P= 0.66) but two deaths occurred in Group B. The laser approach had higher material cost (P= 0.002). CONCLUSIONS: Although laser-assisted TLE was more effective than polypropylene sheath-assisted TLE, the latter was associated with fewer complications and was more cost-effective.