A Systematic Review of Nonsurgical Vulvovaginal Restoration Devices: An Evidence-Based Examination of Safety and Efficacy.

BACKGROUND: The efficacy and safety of vulvovaginal restoration devices were called into question in a U.S. Food and Drug Administration statement on July 30, 2018, claiming that women are being harmed by laser and other energy-based devices. The goal of this systematic literature review was to assess existing data, determine gaps in evidence, and propose opportunities for continued investigation pertaining to laser and energy-based vaginal restoration techniques. METHODS: A review of literature using PubMed, Cochrane Library databases, Embase, MEDLINE, and the Cumulative Index to Nursing and Allied Health Literature was conducted on January 9, 2019, and articles up to this point were considered. For inclusion, studies had to be available or translated in English and relate to clinical medicine, direct patient care, and nonsurgical energy-based vulvovaginal procedures. RESULTS: The authors found five level I studies, 19 level II studies, four level III studies, and 46 level IV studies that used 15 different devices. Various degrees of improvement of symptoms were reported in all studies. Adverse events/side effects were noted in two of the 13 radiofrequency device studies, 15 of the 23 erbium:yttrium-aluminum-garnet device studies, and 17 of the 37 carbon dioxide device studies. The majority of adverse events were considered mild. CONCLUSIONS: The majority of studies resulted in mild to no adverse side effects. However, there is a large gap in level I evidence. As a result, the authors emphasize the necessity of supplemental data surrounding this subject and suggest that additional randomized sham-controlled studies be conducted to further investigate vulvovaginal restoration devices in an effort to address women's health issues.

Lasers for stone treatment: how safe are they?

PURPOSE OF REVIEW: To update laser lithotripsy advances in regard to new laser types and technologies as well as review contemporary laser safety concerns. RECENT FINDINGS: The high prevalence of urolithiasis and the continuing miniaturization of scopes has encouraged the growth of laser lithotripsy technology. The holmium:yttrium-aluminum-garnet (Ho:YAG) laser has been used for over 20 years in endourology and has been extensively studied. Holmium laser power output is affected by a number of factors, including pulse energy, pulse frequency, and pulse width. Several recent experimental studies suggest that the new dual-phase Moses 'pulse modulation' technology, introduced in high-power laser machines, carries a potential to increase stone ablation efficiency and decrease stone retropulsion. A newly introduced thulium fiber laser (TFL) has been adapted to a very small laser fiber size and is able to generate very low pulse energy and very high pulse frequency. Both of these technologies promise to play a larger role in laser lithotripsy in the near future. However, more experimental and clinical studies are needed to expand on these early experimental findings. Even though laser lithotripsy is considered safe, precautions should be taken to avoid harmful or even catastrophic adverse events to the patient or the operating room staff. SUMMARY: The Ho:YAG laser remains the clinical gold standard for laser lithotripsy for over the last two decades. High-power Ho:YAG laser machines with Moses technology have the potential to decrease stone retropulsion and enhance efficiency of laser ablation. The new TFL has a potential to compete with and perhaps even replace the Ho:YAG laser for laser lithotripsy. Safety precautions should be taken into consideration during laser lithotripsy.

Are We Cutting Ourselves Short? Laser Lithotripsy Performance Based on Differences in Fiber-tip Preparation.

OBJECTIVE: To better understand the impact of laser fiber-tip configuration on lithotripsy performance, we undertook an in vitro study comparing 3 fiber-tip configurations: (1) new (single-use), (2) cleaved (reusable), and (3) coated (cut with scissors). METHODS: Lithotripsy was performed using a Ho:YAG laser utilizing fragmentation (1 J × 10 Hz) and dusting (0.5 J × 20 Hz) settings. BegoStones were fragmented with a laser fiber advancing at a speed of 1 mm/s (220 seconds of activation). Three fiber-tip configurations were tested: new single-use standard (242 µm core) and cleaved (272 µm core), compared to the same fiber-tip coated/cut flush with scissors, respectively. Study outcome was difference in stone mass before and after each experiment. Power output was measured using a power meter. RESULTS: Fragmentation for new or cleaved fibers was greater than the coated/cut flush fiber-tip (P <.05). For 1 J × 10 Hz and 0.5 J × 20 Hz settings, fragmentation was 59% and 75% higher with new fiber-tip compared to the coated/cut flush fiber-tip, respectively. For 1J × 10 Hz and 0.5 J × 20 Hz settings, fragmentation was 51% and 45% higher with cleaved fiber-tip compared to the coated/cut flush fiber-tip, respectively. Power output at the end of laser activation was higher for new and cleaved fiber-tips. CONCLUSION: New and cleaved laser fibers demonstrated superior lithotripsy performance compared to fibers that were coated/cut flush with scissors. Cutting single-use laser fibers risks damaging the fiber-tip which can disperse the energy and reduce lithotripsy efficiency.

Rationale for Robotic-assisted Simple Prostatectomy for Benign Prostatic Obstruction.

Current evidence supports the role of robotic-assisted simple prostatectomy as safe and effective minimally invasive surgical treatment of benign prostatic obstruction.

Experimental Evaluation of Percutaneous Lumbar Laser Disc Decompression Using a 1414 nm Nd:YAG Laser.

BACKGROUND: Laser ablation under an epiduroscopic view allows for the vaporization of a small amount of the nucleus pulposus, causing a reduction in intradiscal pressure and relief of radicular pain. Currently, Ho:YAG and Nd:YAG lasers are commonly used for spinal diseases. However, the use of the Nd:YAG laser for intra-spinal procedures can be limited because of thermal injury and low efficacy. OBJECTIVE: To investigate the efficacy and safety of epiduroscopic laser ablation using a 1414 nm Nd:YAG laser, we examined that laser ablation was able to penetrate nucleus pulposus without heating surrounding tissues and without mechanical damage to surrounding tissue. STUDY DESIGN: Our experiment involved live and cadaveric animal studies and a human cadaveric study. SETTING: University in Korea. METHODS: Two live pigs, 3 porcine cadavers, and 2 human cadavers were used. For the in vitro study, intradiscal and epidural pressure and temperature were compared in vertebral columns obtained from 3 porcine cadavers before and after laser ablation. For the in vivo study, 2 pigs were used to simulate percutaneous epiduroscopic laser ablation. They were observed for behavioral changes and neurological deficits for one month after the laser ablation procedure. Two human cadavers were used for placing the laser fiber and epiduroscope in the correct target site through the sacral hiatus. Histological analysis was also performed to observe any damage around the ablated lesion. RESULTS: Both intradiscal and epidural pressure were markedly reduced immediately after laser ablation as compared with the pre-ablative state. The amount of the pressure decrease in the intradiscal space was significantly greater than that in the epidural space (45.8 ± 15.0 psi vs. 30.0 ± 9.6 psi, P = 0.000). The temperature beneath the ipsilateral spinal nerve, which was the nearest site to the laser probe, never exceeded 40° C. Histology revealed no evidence of thermal damage to surrounding structures, including the spinal nerves, end plates, and vertebrae, after laser ablation. All live pigs showed normal behavior without any sign of pain. In the human cadaveric study, there was no case of targeting failure or dural laceration. The mean time to reach the target region was less than 5 minutes. LIMITATIONS: The pressure measurements were performed on cadavers and not in vivo. Cadaver models cannot account for intradiscal pressure changes that occur during live muscle contraction and different positions, which may affect results. Moreover, although we controlled temperatures with heat baths, vascular and cerebrospinal fluid circulations were not simulated. Those circulations may change the temperature results in vivo. CONCLUSIONS: The 1414 nm Nd:YAG laser can be used effectively and safely under the guidance of a spinal epiduroscope in an in vivo porcine model and in a human cadaveric model. STUDY APPROVAL: Approval for the current study was granted by the Institutional Review Board of our institute (approval number: 1-2014-0049).

Influence of the Nd:YAG laser pulse duration on the temperature of primary enamel.

The aim of this study is to evaluate the temperature change on specimens of primary enamel irradiated with different pulse duration of Nd:YAG laser. Fifteen sound primary molars were sectioned mesiodistally, resulting in 30 specimens (3.5 × 3.5 × 2.0 mm). Two small holes were made on the dentin surface in which K-type thermocouples were installed to evaluate thermal changes. Specimens were randomly assigned in 3 groups (n = 10): A = EL (extra long pulse, 10.000 µs), B = LP (long pulse, 700 µs), and C = SP (short pulse, 350 µs). Nd:YAG laser (λ = 1.064 µm) was applied at contact mode (10 Hz, 0.8 W, 80 mJ) and energy density of 0.637 mJ/mm(2). Analysis of variance (ANOVA) was performed for the statistical analysis (P = 0.46). Nd:YAG laser pulse duration provided no difference on the temperature changes on primary enamel, in which the following means were observed: A = EL (23.15°C ± 7.75), B = LP (27.33°C ± 11.32), and C = SP (26.91°C ± 12.85). It can be concluded that the duration of the laser pulse Nd:YAG increased the temperature of the primary enamel but was not influenced by different pulse durations used in the irradiation.

Noninvasive delivery of siRNA and plasmid DNA into skin by fractional ablation: erbium:YAG laser versus CO2 laser.

The present study was conducted to evaluate the impacts of fractional erbium (Er):YAG and CO2 lasers on skin permeation of small interfering (si)RNA and plasmid (p)DNA vectors. In vitro skin delivery was determined with a Franz diffusion cell. In vivo absorption was investigated by observing fluorescence and confocal microscopic imaging. Fractional laser-mediated ablation of the skin resulted in significant enhancement of dextran and siRNA penetration. Respective fluxes of dextran (10 kDa) and siRNA, which had similar molecular size, with Er:YAG laser irradiation at 5 J/cm(2) were 56- and 11-fold superior to that of intact skin. The respective permeation extents of dextran and siRNA by the CO2 laser at 4 mJ/400 spots were 42- and 12-fold greater than that of untreated skin. Fluorescence and confocal images showed increased fluorescence intensities and penetration depths of siRNA and pDNA delivery. According to an examination of the follicular permeant amount and fluorescence microscopy, hair follicles were important deposition areas for fractional laser-assisted delivery, with the Er:YAG modality revealing higher follicular siRNA selectivity than the CO2 modality. This is the first report of siRNA and pDNA penetrating the skin with a sufficient amount and depth with the assistance of fractional lasers.

Could titanium oxide coating from a sol-gel process make stone baskets more resistant to laser radiation at 2.1 µm?

BACKGROUND: Stone baskets could be easily destroyed by Holmium:YAG-laser at an endourologic treatment, with respect to this, we try to improve the resistance by coating them with a titanium oxide layer. The layer was established by a sol-gel-process. MATERIALS AND METHODS: Six new baskets (Equadus, Opi Med, Ettlingen, Germany) were used: 1.8 Ch. with 4 wires (diameter 0.127 mm). Three baskets were coated with a layer of titanium oxide established by a sol-gel process at the BioCerEntwicklungs GmbH in Bayreuth (~100 nanometres thickness). The lithotripter was a Holmium:YAG laser (Auriga XL, Starmedtec, Starnberg, Germany). 10 uncoated and 10 coated wires were tested with 610 mJ (the minimal clinical setting) and 2 uncoated and 2 coated wires were tested with 110 mJ. The wires were locked in a special holding instrument under water and the laser incident angle was 90°. The endpoint was gross visible damage to the wire and loss of electric conduction. RESULTS: Only two coated wires resisted two pulses (one in the 610 mJ and one in the 110 mJ setting). All other wires were destroyed after one pulse. CONCLUSION: This was the first attempt at making stone baskets more resistant to a Holmium:YAG laser beam. Titanium oxide deposited by a sol-gel-process on a titanium-nickel alloy did not result in better resistance to laser injuries.

Demonstration of on-sky calibration of astronomical spectra using a 25 GHz near-IR laser frequency comb.

We describe and characterize a 25 GHz laser frequency comb based on a cavity-filtered erbium fiber mode-locked laser. The comb provides a uniform array of optical frequencies spanning 1450 nm to 1700 nm, and is stabilized by use of a global positioning system referenced atomic clock. This comb was deployed at the 9.2 m Hobby-Eberly telescope at the McDonald Observatory where it was used as a radial velocity calibration source for the fiber-fed Pathfinder near-infrared spectrograph. Stellar targets were observed in three echelle orders over four nights, and radial velocity precision of ∼10 m/s (∼6 MHz) was achieved from the comb-calibrated spectra.

Performance assessment of novel side firing safe tips for endodontic applications.

During root canal or periodontal treatment, directing laser energy onto the walls of the root canal is essential for effective disinfection. This study assessed the performance of four different fiber modifications that have increased lateral emission, including three designs with safe tips to reduce irradiation directed toward the root apex. Free-running pulsed infrared lasers (Nd:YAG, Er:YAG, and Er,Cr:YSGG) and a diode laser (980 nm) were used in combination with plain ended (forward emitting) laser fibers; conical laser fibers, side firing honeycomb pattern fibers without a safe end; honeycomb fibers with silver coated ends, conical fibers with selectively abraded tips, and selectively abraded honeycomb fibers with silver coated tips (20 fibers for each laser type). Laser emissions forward and laterally were measured, and digital photographs and thermally sensitive paper used to record the emission profiles. Thermochromic dyes painted onto the root surface of an extracted tooth were used to explore the distribution of laser energy with different tips designs. All three safe tipped ends gave reduced emissions in the forward direction (range 17-59%), but had similar lateral emission characteristics. Fiber designs with reduced forward emission may be useful for various dental laser procedures.

70 vs 120 W thulium:yttrium-aluminium-garnet 2 microm continuous-wave laser for the treatment of benign prostatic hyperplasia: a systematic ex-vivo evaluation.

OBJECTIVE: To evaluate the ablative and haemostatic properties of the recently introduced 120-W thulium:yttrium-aluminium-garnet (Tm-YAG) laser and to assess these results against those of the previously introduced 70-W Tm-YAG laser. MATERIALS AND METHODS: The ex-vivo model of the isolated blood-perfused porcine kidney was used to determine the ablation capacity, haemostatic properties and coagulation depth of a 2 microm continuous-wave Tm-YAG laser. The energy was delivered using a 550-microm and an 800-microm bare-ended fibre. The results of the recently introduced 120-W Tm-YAG were compared to the established 70-W device. Kidney tissue was embedded for histological evaluation. After staining (haematoxylin and eosin, H & E; and NADH) of the specimen, the coagulation zone and depth of the necrotic tissue layer were measured. RESULTS: With increased power output, the mean (sd) rate of vaporization of tissue increased, from 9.80 (3.03) g/10 min at 70 W to 16.41 (5.2) g/10 min at 120 W using the 550 microm fibre. The total amount of ablated tissue using the 800 microm fibre was lower than with the 550 microm fibre. With increasing power output the bleeding rate remained stable in either group. Tissue penetration remained shallow, even with increasing power output. In contrast to H&E staining, where the coagulation zone was measured, NADH staining showed an inner zone of necrotic tissue, again with no difference between the 70- and the 120-W Tm-YAG. CONCLUSION: The 120-W Tm-YAG offers significantly higher ablation rates than the 70-W device, and despite the increased rate of ablation with the 120-W Tm-YAG, the bleeding rate and depth of tissue penetration were comparable to those using the 70-W device.

Prospective single-centre comparison of 120-W diode-pumped solid-state high-intensity system laser vaporization of the prostate and 200-W high-intensive diode-laser ablation of the prostate for treating benign prostatic hyperplasia.

OBJECTIVE: To evaluate the safety, efficacy and short-term outcome of a new 980 nm high-intensity diode (HiDi) laser (Limmer Laser, Berlin, Germany) system in comparison to the diode-pumped solid-state laser high-performance system (HPS; GreenLight(TM), AMS, Minnetonka, MI, USA) for treating benign prostatic hyperplasia (BPH) in a prospective non-randomized single-centre study. PATIENTS AND METHODS: From February to September 2007, 117 consecutive patients with lower urinary tract symptoms secondary to BPH were included; 62 patients were treated with 120-W HPS laser vaporization and 55 with 980-nm HiDi laser ablation of the prostate. We evaluated perioperative variables, and complications during and after surgery. Patients presenting for follow-up completed the International Prostate Symptom Score, and had their maximum urinary flow rate and postvoid residual urine volume measured. RESULTS: The mean (sd) age of the patients was 72.3 (8.8) years (HiDi) and 73.1 (10.8) years (HPS), with a mean preoperative prostate volume of 64.7 (29.7) and 67.4 (46.9) mL, respectively. The mean operative duration was comparable, at 56.4 (20.2) and 62.7 (36.3) min, respectively, whereas the mean energy delivery was significantly higher with the diode laser, at 313 (132) vs 187 (129) kJ (P < 0.001). For patients treated with the HPS the rate of visual impairment from bleeding was higher (0% vs 12.9%, P < 0.01), as was prostate capsule perforation (0% vs 4.8%, P > 0.05). Soon after surgery the rate of dysuria (23.6% vs 17.7%, P > 0.05) and transient urge incontinence (7.3% vs 0%; P < 0.05) was higher for the HiDi laser. During the follow-up there were higher rates of bladder neck stricture (14.5% vs 1.6%, P < 0.01), re-treatment (18.2% vs 1.6%, P < 0.01) and stress urinary incontinence (9.1% vs 0%; P < 0.05) for the HiDi laser group. CONCLUSION: Both systems investigated provide good tissue ablative properties. The HiDi laser at 980 nm is more favourable in terms of haemostasis. The penetration depths, resulting in coagulation necrosis and leading to increased re-treatment, bladder neck stricture and incontinence rates, were higher with the HiDi laser.

Thulium:yttrium-aluminium-garnet laser prostatectomy in men with refractory urinary retention.

OBJECTIVE: To evaluate the feasibility and efficacy of thulium:yttrium-aluminium-garnet (YAG) laser prostatectomy in patients with an indwelling transurethral catheter due to recurrent urinary retention secondary to benign prostatic obstruction. PATIENTS AND METHODS: Preoperative data and postoperative outcome, as well as complications, were recorded in 65 patients with a history of recurrent urinary retention before surgery (group A), who were compared with a group of 143 men with no recurrent urinary retention (group B). RESULTS: The mean (sd) volume of the prostate was 45.6 (22.5) and 43.1 (24.5) mL in groups A and B, respectively. The respective preoperative prostate-specific antigen levels were 3.6 (7.8) and 2.8 (6.4) ng/mL, the surgical duration 72.4 (28.9) and 65.6 (28.6) min, the mean laser time and energy 32.5 (11.8) min/140.7 (42.1) kJ and 29.4 (11.6) min/117.6 (11.6) kJ, the maximum urinary flow rate after surgery 19.6 (11.2) and 19.1 (9.6) mL/s, and the postvoid residual urine volume 26.7 (36.3) and 20.6 (27.3) mL. Recorded complications were: bleeding, at 3% in group A and 1.4% in group B; urinary tract infection 15.4% and 4.2%; and a second procedure, 3% and 2.3%. Overall, complications were more frequent in group A (P = 0.02). CONCLUSION: Thulium:YAG prostatectomy is feasible and effective, even in patients with potentially impaired detrusor function. The long-term durability of these promising results has yet to be confirmed.

Holmium laser prostatic resection for patients presenting with acute urinary retention.

OBJECTIVE: To compare the outcomes of patients presenting with and without acute urinary retention (AUR) who were treated with 100-W holmium laser resection of the prostate (HoLRP), as laser therapies, including HoLRP, have been used for treating lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH), but the effectiveness of HoLRP for patients with AUR has not been fully elucidated. PATIENTS AND METHODS: The medical records of 87 patients who had HoLRP were reviewed, and prospective questionnaires aimed at determining patients' American Urologic Association Symptom Index (AUA-SI) and Quality-of-Life (QoL) scores and medication usage were also obtained. Statistical analyses were used to compare the clinical characteristics and outcomes between patients with and with no AUR for up to 2 years after HoLRP. RESULTS: All patients had the catheter removed successfully by 1 month after surgery; those presenting with AUR tended to have a greater improvement in clinical outcomes than those with no AUR, including a mean AUA-SI score decrease by approximately 13 and approximately 8 points, and a QoL score decrease by approximately 2 and approximately 1.4 points, respectively. These decreases were maintained throughout the study period. Patients with AUR had significantly greater decreases in their postvoid residual urine volume than those with no AUR. Serum prostate-specific antigen levels also had a modest but sustained decrease (14%) in both groups. There were no significant decreases in the reported use of BPH-related medications after surgery in either group. CONCLUSIONS: HoLRP (100 W) is a safe and effective surgical therapy for patients presenting with AUR. The present results suggest that the short- and long-term outcomes of these patients are similar between men presenting with and with no AUR.