How I Do It: Teaching holmium laser enucleation of the prostate (HoLEP).

Holmium laser enucleation of the prostate (HoLEP) is considered a size-independent technique to treat benign prostatic hyperplasia. This safe and effective procedure is increasingly being adopted in urology training programs worldwide, yet limited teaching strategies have been described. Endoscopic handling during HoLEP allows for a simultaneous interaction between the surgeon and trainee, facilitating a guided teaching strategy with increasing difficulty as experience grows. In this article, we describe our stepwise approach for teaching HoLEP as part of a structured surgical training curriculum. We also evaluate the association of our method with intraoperative efficiency parameters and immediate postoperative surgical outcomes of 200 HoLEP procedures.

Spatially modulated ablation driven by chaotic attractors in human lung epithelial cancer cells.

A significant modification in photoinduced energy transfer in cancer cells is reported by the assistance of a dynamic modulation of the beam size of laser irradiation. Human lung epithelial cancer cells in monolayer form were studied. In contrast to the quantum and thermal ablation effect promoted by a standard focused Gaussian beam, a spatially modulated beam can caused around 15% of decrease in the ablation threshold and formation of a ring-shaped distribution of the photothermal transfer effect. Optical irradiation was conducted in A549 cells by a 532 nm single-beam emerging from a Nd:YVO4 system. Ablation effects derived from spatially modulated convergent waves were controlled by an electrically focus-tunable lens. The proposed chaotic behavior of the spatial modulation followed an Arneodo chaotic oscillator. Fractional dynamic thermal transport was analyzed in order to describe photoenergy in propagation through the samples. Immediate applications of chaos theory for developing phototechnology devices driving biological functions or phototherapy treatments can be considered.

Comparison of urinary incontinence following three different prostate apex disconnection techniques in transurethral thulium laser prostatectomy.

OBJECTIVE: This study investigates the incidence of urinary incontinence following transurethral thulium laser prostatectomy with three different prostate apex disconnection techniques: semi-separation, pre-separation, and post-separation. The findings aim to provide references for clinical treatment. PATIENTS AND METHODS: A retrospective analysis was conducted on 74 patients treated with transurethral thulium laser prostatectomy for prostatic hyperplasia from April 2022 to March 2023. Complete clinical and follow-up data were available for 52 patients. Clinical and follow-up data were collected for these patients. A comparison was made of urinary incontinence following the three different types of prostate apex disconnection in transurethral thulium laser prostatectomy. RESULTS: In this study, the immediate postoperative urinary incontinence rate for transurethral thulium laser prostatectomy was 9.62% (5/52), the short-term incontinence rate was 11.54% (5/52), and the long-term incontinence rate was 9.62% (5/52). The immediate postoperative incontinence rates for semi-separation, pre-separation, and post- separation were 8.33% (1/12), 8.33% (2/24), and 12.5% (2/16), respectively. The short-term incontinence rates for semi-separation, pre-separation, and post-separation were 8.33% (1/12), 8.33% (2/24), and 18.75% (3/16), respectively. The long-term incontinence rates for semi-separation, pre-separation, and post-separation were 8.33% (1/12), 8.33% (2/24), and 12.5% (2/16), respectively. CONCLUSIONS: The incidence of urinary incontinence following transurethral thulium laser prostatectomy was lower with semi-separation and pre-separation compared to post-separation.

Bio-thermal response during laser haemorrhoidoplasty: an exclusive analytical and numerical approach for theoretical investigation.

Haemorrhoidal disease is identified by declension of the inflamed and bleeding of vascular tissues of the anal canal. Traditionally, haemorrhoids are associated with chronic constipation and the most common symptoms are irritation in anus region, pain and discomfort, swelling around anus, tender lumps around the anus and rectal bleeding (depending upon the grade of haemorrhoid). Among the several conventional treatment procedures (commonly mentioned as, rubber band litigation, sclerotherapy and electrotherapy), laser haemorrhoidoplasty is an out-patient and less-invasive laparoscopic procedure. From literature survey it has been observed that an exclusive theoretical model depicting the impact of 1064 nm wavelength laser wave on living tissues subjected to haemorrhoid therapy is not available. This research work is a pioneering attempt to develop a theoretical study attributing specifically on laser therapy of haemorrhoid treatment based on Pennes' biological heat transfer model. The corresponding mathematical model has been solved by analytical method to establish thermal response of tissue during the treatment and also the same has been solved a numerical approach based on finite difference method to validate the feasibility of former method due to unavailability of any theoretical model. Impact of variation of blood perfusion term, laser pulse time and optical penetration depth on temperature response of skin tissue is captured. The tissue temperature decreases along with time of laser exposure with increasing the blood perfusion rate as it carries away large amount of heat. With the increase in laser pulse time, tissue temperature declines due to shorter pulse time resulting in higher energy consumed by electrons. The research outcome is successfully validated with less than 1% of error observed between the appointed analytical and numerical scheme.

Incidence of complications and urinary incontinence following endoscopic enucleation of the prostate in men with a prostate volume of 80 ml and above: results from a multicenter, real-world experience of 2512 patients.

PURPOSE: To evaluate complications and urinary incontinence (UI) after endoscopic enucleation of the prostate (EEP) stratified by prostate volume (PV). METHODS: We retrospectively reviewed patients with benign prostatic hyperplasia who underwent EEP with different energy sources in 14 centers (January 2019-January 2023). INCLUSION CRITERIA: prostate volume ≥ 80 ml. EXCLUSION CRITERIA: prostate cancer, previous prostate/urethral surgery, pelvic radiotherapy. PRIMARY OUTCOME: complication rate. SECONDARY OUTCOMES: incidence of and factors affecting postoperative UI. Patients were divided into 3 groups. Group 1: PV = 80-100 ml; Group 2 PV = 101-200 ml; Group 3 PV > 200 ml. Multivariable logistic regression analysis was performed to evaluate independent predictors of overall incontinence. RESULTS: There were 486 patients in Group 1, 1830 in Group 2, and 196 in Group 3. The most commonly used energy was high-power Holmium laser followed by Thulium fiber laser in all groups. Enucleation, morcellation, and total surgical time were significantly longer in Group 2. There was no significant difference in overall 30-day complications and readmission rates. Incontinence incidence was similar (12.1% in Group 1 vs. 13.2% in Group 2 vs. 11.7% in Group 3, p = 0.72). The rate of stress and mixed incontinence was higher in Group 1. Multivariable regression analysis showed that age (OR 1.019 95% CI 1.003-1.035) was the only factor significantly associated with higher odds of incontinence. CONCLUSIONS: PV has no influence on complication and UI rates following EEP. Age is risk factor of postoperative UI.

Laser Therapy Effects on Periodontal Status: A Randomized Study Using Gaussian Network Analysis and Structural Equation Modeling Approach.

Background and Objectives: This paper aims to assess the role of laser therapy in periodontitis through an innovative approach involving computational prediction and advanced modeling performed through network analysis (Gaussian graphical models-GGMs) and structural equations (SEM). Materials and Methods: Forty patients, exhibiting periodontal pockets with a minimum depth of 5 mm, were randomly divided into two groups: a control group and a laser group. Four specific indicators were measured for each tooth, namely periodontal pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), and plaque index (PI), and the mean of six measured values was recorded at five time markers (baseline, 6 months, 1 year, 2 years, and 4 years). The assessment algorithm included enrollment, measurements, and differential non-surgical periodontal treatment, according to the group allocation. Scaling, root planing, and chlorhexidine 1% were conducted for the control group, and scaling, root planing and erbium, chromium:yttrium-scandium-gallium-garnet (Er,CR:YSGG) laser therapy were conducted for the laser group. Results: The main results highlight that the addition of laser treatment to scaling and root planing led to notable clinical improvements, decreasing the PPD values, reducing the BOP scores, and increasing the CAL. Conclusions: Notable relationships between the specific indicators considered were highlighted by both the GGMs and by SEM, thus confirming their suitability as proxies for the success of periodontal treatment.

Pulse modulation in En-Bloc HoLEP: does it really matter? A propensity score matched analysis.

INTRODUCTION: Holmium laser enucleation of the prostate (HoLEP) is an established option in the surgical treatment of benign prostatic hyperplasia. Pulse modulation, such as MOSES® technology, has recently been introduced and may offer potential advantages in HoLEP. METHODS: Perioperative data from 117 patients who underwent MOSES® laser enucleation of the prostate (MoLEP) were collected. Propensity score matching using prostate volume, age, body mass index (BMI), and anticoagulant intake was performed using a database of 237 patients treated with HoLEP. In total, 234 patients were included in the analysis. RESULTS: Prostate volume (104 vs. 102 ml), age (70 vs. 71 years), BMI (27 vs. 27), and anticoagulant intake (34 vs. 35%) did not differ significantly between the groups. There were no significant differences in operation time (61.5 vs. 58.1 min, p = 0.42), enucleation efficiency (2.5 vs. 2.6 g/min, p = 0.74), hemostasis time (7.8 vs. 8 min, p = 0.75) and hemoglobin drop (0.9 vs. 0.7 mg/dl, p = 0.48). The complication rates were low in both groups (16.2% for HoLEP and 17.1% for MoLEP). No differences were noted in the Clavien-Dindo Classification (p = 0.63) and the Comprehensive Complication Index (p = 0.24). The rate of complications > CDC IIIa was 0.9% for HoLEP (endoscopic coagulation) and 1.7% for MoLEP (2 cases of endoscopic coagulation). No transfusions were administered. CONCLUSION: Overall, the enucleation efficiency was high in both groups and the procedure time was short. HoLEP is an efficient and safe treatment option in experienced hands, regardless of the use of pulse modulation technology.

Revisiting the issue of "beach balls" in holmium laser enucleation of prostate: clinical and histological characterization.

PURPOSE: To clinically and histologically characterize prostatic nodules resistant to morcellation ("beach balls," BBs). PATIENTS AND METHODS: We reviewed a consecutive cohort of 559 holmium laser enucleation of the prostate (HoLEP) procedures performed between January 2020 and November 2023. The BBs group comprised 55 men (10%) and the control group comprised 504 men (90%). The clinical, intraoperative, outcome, and histologic data were statistically processed for the prediction of the presence of BBs and their influence on the perioperative course and outcome. RESULTS: The BBs group in comparison to the controls was older (75 vs 73 years, respectively, p = 0.009) and had higher rates of chronic retention (51 vs 29%, p = 0.001), larger prostates on preoperative abdominal ultrasound (AUS) (140 vs 80 cc, p = 0.006E-16), longer operating time (120 vs 80 min, p = 0.001), higher weights of removed tissue (101 vs 60 gr, p = 0.008E-10), higher complication rates (5 vs 1%, p = 0.03), and longer hospitalization (p = 0.014). A multivariate analysis revealed that larger prostates on preoperative AUS and older age independently predicted the presence of BBs which would prolong operating time. ROC analyses revealed that a threshold of 103 cc on AUS predicted BBs with 94% sensitivity and 84% specificity. BBs were mostly characterized histologically by stromal component (p = 0.005). CONCLUSIONS: BBs are expected in older patients and cases of chronic retention. Prostatic volume is the most reliable predictor of their presence. They contribute to prolonged operating time and increased risk of complications. The predominantly stromal composition of the BBs apparently confers their resistance to morcellation.

New approaches to second-degree burn healing: Polyvinyl alcohol membrane loaded to arnica combined to laser therapy.

Second-degree burns require greater care, as the damage is more extensive and worrisome and the use of a biomaterial can help in the cell repair process, with better planning, low cost, and better accessibility. Arnica has anti-inflammatory and analgesic properties in skin lesions treatments and laser therapy is another therapeutic alternative for burns. Evaluate the effects of arnica incorporated into PVA associated or not with low intensity laser on burns in rats. PVA and PVA with arnica (PVA+A) were obtained and characterized physicochemically. Through in vivo studies, the effects of PVA and PVA+A with or without the application of laser on the lesions allowed histological and immunohistochemical analyzes. PVA+A was biocompatible and with sustained release of the active, being a promising pharmacological tool and confirmed that laser therapy was effective in accelerating the healing process, due to its potential biomodulator, improving inflammatory aspects, promoting rapid healing in skin lesions.

Propensity score-matched analysis comparing perioperative, functional, and safety outcomes between thulium fiber laser and bipolar enucleation of the prostate performed by a single surgeon with two years of follow-up.

PURPOSE: To compare perioperative, functional, and safety outcomes between thulium fiber laser enucleation of the prostate (ThuFLEP) and bipolar enucleation of the prostate performed by a single surgeon with use of propensity score (PS)-matched analysis. MATERIALS AND METHODS: Data were from 675 patients, 422 of whom underwent ThuFLEP and bipolar enucleation by a single highly experienced surgeon. ThuFLEP was performed with Fiberlase U1 (IRE Polus Ltd.). Perioperative parameters, safety, and functional outcomes, such as International Prostate Symptom Score (IPSS), quality of life (QoL), postvoid residual volume (PVR), and maximum urinary flow rate (Qmax) were assessed. To control for selection bias, a 1:1 PS-matched analysis was carried out using the following variables as covariates: total prostate volume, preoperative IPSS and early sphincter release. RESULTS: Of 422 patients, 370 (87.7%) underwent ThuFLEP and 52 (12.3%) underwent bipolar enucleation. Operation, enucleation, and morcellation time were comparable between groups before and after PS-matched analysis (p=0.954, p=0.474, p=0.362, respectively). Functional parameters (IPSS, QoL, PVR, Qmax) were also comparable between groups at every time point before and after PS matching. Significant improvements in IPSS, QoL score, Qmax, and PVR were observed during the 24-month follow-up period for both ThuFLEP and bipolar enucleation without any significant differences between groups. Early and late postoperative complications before and after PS-matched analysis were similar. CONCLUSIONS: ThuFLEP was comparable to bipolar enucleation in perioperative characteristics, improvement in voiding parameters, and complication rates. Both procedures were shown to be effective and safe in the management of benign prostatic hyperplasia.

Therapeutic efficacy of 180-W GreenLight laser photoselective vaporization of the prostate for storage symptoms concomitant with benign prostatic obstruction and a search for outcome predictors.

PURPOSE: Benign prostatic obstruction (BPO) is the most common cause of lower urinary tract symptoms among men. GreenLight photoselective vaporization of the prostate (GL-PVP) using a 180-W Xcelerated performance system (XPS) laser is a well-established method for treating BPO-induced voiding symptoms. However, its therapeutic effects on storage symptoms remain unclear. This study aimed to analyze the storage outcomes in patients who underwent 180-W XPS GL-PVP for BPO and to identify outcome predictors. MATERIALS AND METHODS: Patients who underwent 180-W XPS GL-PVP for BPO between May 2018 and May 2021 were retrospectively reviewed. Data on clinical characteristics, prostate volume, preoperative and postoperative International Prostate Symptom Scores (IPSS), and preoperative urodynamic parameters were collected. A favorable storage outcome was defined as ≥50% reduction in the IPSS storage subscore. RESULTS: Ninety-nine male patients were included, with a mean age of 69.4 ± 9.6 years and a baseline prostatic volume of 75.9 ± 33.1 mL. The IPSS total, storage, and voiding subscores significantly decreased after GL-PVP (all p < 0.001). Seventy-two patients achieved favorable storage outcome at 6 months. Multivariate analysis revealed that detrusor underactivity was predictive of unfavorable storage outcomes (p = 0.022), while IPSS voiding-to-storage subscore ratio >1.25 and the presence of detrusor overactivity were predictive of favorable storage outcomes (p = 0.008 and 0.033, respectively). CONCLUSION: 180-W XPS GL-PVP provided excellent outcomes in both voiding and storage lower urinary tract symptoms concomitant with BPO. Preoperative IPSS and multichannel urodynamic parameters including detrusor overactivity and underactivity are valuable predictors of postoperative storage outcomes.

Meta-analysis of the impact of laser interstitial hyperthermia on wound healing complications in brain tumors.

High-grade gliomas (HGGs) may be amenable to the neurosurgical technique known as laser interstitial thermal therapy (LITT), which delivers thermal energy to interstitial brain injuries and wounds with pinpoint accuracy. The purpose of this extensive meta-analysis was to evaluate the effects of LITT on wound complications among patients who have brain tumours. Diverse conclusions emerge from a systematic review of pertinent studies, necessitating a comprehensive examination. The meta-analysis, performed utilizing the meta library provided by the R package meta, reveals an initial significant overall effect (RR: -2.1262, 95% CI [-2.7466, -1.5059], p < 0.0001) accompanied by considerable heterogeneity among studies (I2 = 61.13%). Following analyses that specifically examined the incidence of wounds, a complex correlation was found (RR: 0.0471, 95% CI [0.0264, 0.0842], p < 0.0001), indicating that LITT has a discernible but insignificant effect on the occurrence of wounds. Although the meta-analysis emphasizes a notable decrease in wound complications subsequent to LITT treatment, additional research is warranted due to constraints in standardized reporting, data accessibility, and small sample sizes. The results of this study underscore the need for exhaustive protocols to analyse wound complications in patients with brain tumours undergoing LITT.

Salvage holmium laser enucleation of the prostate after previous interventions: a systematic review.

OBJECTIVE: To investigate the feasibility, safety and efficacy of holmium laser enucleation of the prostate (HoLEP) in the re-treatment setting (salvage HoLEP) and compare it to the primary HoLEP procedure that is commonly used for the treatment of benign prostate hyperplasia (BPH). MATERIALS AND METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, PubMed, Scopus, and Cochrane databases were systematically screened, from inception to 8 August 2022. Other potentially eligible studies were retrieved using the reference lists of the included studies. Retrospective and prospective studies, both comparative and non-comparative, were included. RESULTS: A total of 12 studies met the inclusion criteria and were included in the final qualitative synthesis. One study was prospective comparative (non-randomised), seven studies were retrospective comparative, and four studies were retrospective non-comparative or case series. In total, 831 patients were treated with salvage HoLEP in the above studies. Previous intervention before salvage HoLEP ranged among studies. The most commonly performed was transurethral resection of the prostate. Intraoperative parameters of salvage HoLEP were comparable with those reported during primary HoLEP, while all postoperative outcomes were significantly improved after salvage HoLEP and were similar with those observed after primary HoLEP. No major complications were noted after salvage HoLEP according to Clavien-Dindo classification. CONCLUSIONS: Salvage HoLEP after previous interventions for treating recurrent or residual BPH is a feasible, safe, and efficient procedure. Data presented in selected studies, along with the holmium laser's physical properties to resect more tissue and to dissect along the true anatomical plane of BPH, render HoLEP an ideal salvage treatment modality for recurrent or residual BPH symptoms.

Functional and safety outcomes after benign prostatic enlargement surgeries in men with detrusor underactivity compared with normal detrusor contractility: Systematic review and meta-analysis.

INTRODUCTION: Men with detrusor underactivity (DUA) and concomitant bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPE) may present poorer functional outcomes after surgical desobstruction. This study aimed to evaluate the safety and efficacy of BPE surgery in men with DUA compared with those with normal detrusor contractility (NC). MATERIALS AND METHODS: This review was performed according to the 2020 PRISMA framework. A comprehensive literature search was performed until May 7, 2023, using MEDLINE, EMBASE, and Cochrane Database. No date limits were imposed. Only comparative studies were accepted. The primary endpoint was to assess if there was any difference in short- and long-term functional outcomes after BPE surgery in men with DUA and NC. The secondary endpoint was to evaluate the differences in perioperative outcomes and postoperative complications between the two groups. Meta-analysis was performed using Review Manager (RevMan) software. RESULTS: There were 5 prospective nonrandomized studies and 12 retrospective studies, including 1701 DUA and 1993 NC patients. Regarding surgical procedures, there were eight TURP (transurethral resection of the prostate) studies, four GreenLight PVP (photoselective vaporization of the prostate) studies, two HoLEP (Holmium laser enucleation of the prostate) studies, one GreenLight PVP/HoLEP study, one Holmium laser incision of the prostate study, and one study did not report the type of surgery. We did not find a statistically significant difference between the two groups in terms of perioperative outcomes, including postoperative catheterization time, hospitalization time, urinary retention, need to recatheterization, transfusion rate, or urinary tract infections. Also, we found no significant differences in long-term complications, such as bladder neck stenosis or urethral stenosis. Posttreatment bladder recatheterization and retreatment rate for BPE regrowth could not be evaluated properly, because only one study reported these findings. When we analyzed functional outcomes at 3 months, those with NC had lower International Prostatic Symptom Score (IPSS), lower quality-of-life (QoL) score, better maximum flow rate (Qmax), and lower post-voiding residual (PVR) of urine. These results were maintained at 6 months postoperatively, with exception of PVR that showed no difference. However, at 12 and more than 12 months the functional outcomes became similar regarding IPSS and QoL. There were few data about Qmax and PVR at longer follow-up. CONCLUSION: In this meta-analysis, data suggest that BOO surgical treatment in patients with concomitant BPE and DUA appears to be safe. Despite patients with DUA may present worse functional outcomes in the short postoperative term compared with the NC population, IPSS and QoL scores become comparable again after a longer follow-up period after surgery.

Fox eyes lift-A new protocol for eyebrow elevation with laser Fotona.

BACKGROUND: The eyelids play an important role in our appearance and are usually the first to show signs of age. The Fotona SP Spectro Systems consist of a range of noninvasive laser treatments that work together synergistically to tighten the collagen in four dimensions and provide long-lasting firmness to the face. The Fotona SP Spectro combines two wavelengths: Er:YAG (2940 nm) and Nd:YAG (1064 nm) with four distinct treatments: SmoothLiftingTM, FRAC3®, PIANO®, and SupErficialTM, allowing safe, painless, noninvasive, and no downtime rejuvenation. AIMS: To present a new protocol of treatment with Fotona SP Spectro for eyebrow elevation, which we call fox eyes lift (FEL), and compare it to the standard SmoothEye® (SE) protocol. METHODS: This is a prospective, interventional, split-face study. The sample consisted of 21 subjects (19 women) with a mean age of 50.1 ± 7.9 years who underwent two different protocols, that is, SE on one side and FEL on the other. The protocol used on each side was selected by drawing lots. Three sessions were held at 1-month intervals. Standardized photographic documentation was obtained before and 30 days after the end of treatment. Eyebrow position before and after complete treatment was quantified using ImageJ software. RESULTS: Statistical analysis by ANOVA showed a significant improvement in eyebrow position after treatment with both protocols, with a significantly greater effect of FEL (p = 0.0003 d = 0.95). CONCLUSION: Fox eyes lift is an efficient and safe technique providing significant improvement in the position of the eyebrow.

Impact of skin hydration on patterns of microthermal injury produced by fractional CO2 laser.

OBJECTIVES: The impact of skin hydration on patterns of thermal injury produced by ablative fractional lasers (AFLs) is insufficiently examined under standardized conditions. Using skin with three different hydration levels, this study assessed the effect of hydration status on microchannel dimensions generated by a fractional CO2 laser. METHODS: A hydration model (hyperhydrated-, dehydrated- and control) was established in ex vivo porcine skin, validated by changes in surface conductance and sample mass. After, samples underwent AFL exposure using a CO2 laser (10,600 nm) at two examined pulse energies (10 and 30 mJ/mb, fixed 10% density, six repetitions per group). Histological assessment of distinct microchannels (n = 60) determined three standardized endpoints in H&E sections: (1) depth of microthermal treatment zones (MTZs), (2) depth of microscopic ablation zones (MAZs), and (3) coagulation zone (CZ) thickness. As a supplemental in vivo assessment, the same laser settings were applied to hyperhydrated- (7-h occlusion) and normohydrated forearm skin (no pretreatment) of a human volunteer. Blinded measurement of MAZ depth (n = 30) was performed using noninvasive optical coherence tomography (OCT). RESULTS: Modest differences in microchannel dimensions were shown between hyperhydrated, dehydrated and control skin at both high and low pulse energy. Compared to controls, hyperhydration led to median reductions in MTZ and MAZ depth ranging from 5% to 8% (control vs. hyperhydrated at 30 mJ/mb; 848 vs. 797 µm (p < 0.003) (MAZ); 928 vs. 856 µm (p < 0.003) (MTZ)), while 14%-16% reductions were shown in dehydrated skin (control vs. dehydrated at 30 mJ/mb; MAZ: 848 vs. 727 µm (p < 0.003); MTZ: 928 vs. 782 µm (p < 0.003)). The impact of skin hydration on CZ thickness was in contrast limited. Corresponding with ex vivo findings, hyperhydration was similarly associated with lower ablative depth in vivo skin. Thus, median MAZ depth in hydrated skin was 10% and 14% lower than in control areas at 10 and 30 mJ/mb pulse energy, respectively (10 mJ: 210 vs. 180 µm (p < 0.001); 30 mJ: 335 vs. 300 µm (p < 0.001)). CONCLUSION: Skin hydration status can exert a minimal impact on patterns of microthermal injury produced by fractional CO2 lasers, although the clinical implication in the context of laser therapy requires further study.