Treatment of hypertrophic scars and keloids using an intralesional 1470 nm bare-fibre diode laser: a novel efficient minimally-invasive technique

Hypertrophic and keloid scars result from abnormal wound healing and can have a variable response to a number of available treatment modalities. The evolution of laser treatments in recent years has shown a wide range of clinical applications including their use in the treatment of scars. We investigated the effectiveness of a 1470 nm diode laser using an intralesional optical fibre delivery device in the treatment of hypertrophic and keloid scars. We evaluated its safety and efficacy as a novel and minimally invasive treatment alternative for scar modulation and volume reduction. A prospective cohort study was performed involving 21 patients with hypertrophic scars (HS) (n = 9) and keloids (n = 12) resulting from various aetiology. Patients were treated with one to three treatment sessions. Comprehensive evaluations were performed using the Vancouver Scar Scale, Doppler ultrasound, Cutometer, Mexameter and PeriCam PSI. Scar thickness was reduced by an average of 0.308 ± 0.138 cm (p < 0.001). In particular the two subgroups showed a significant 27.7% and 28.2% reduction in scar thickness of HS and Keloids, respectively. Scar firmness showed a significant improvement of 1.2% (p < 0.05) for HS, though for keloids this was 0.4% (p = 0.26). Keloids had a significant reduction in pigmentation at 21.3%. Blood perfusion had a significant reduction of 29.6% in HS and 22.7% in Keloids. Overall VSS total score improvement of 42% in the HS and at 37.9% in the Keloid subgroup. No adverse events such as hypo/hyperpigmentation, skin infection, or recurrence were reported. This study shows that the intralesional 1470 nm bare-fibre diode laser significantly improved hypertrophic and keloid scars based on both subjective and objective analyses and supports this type of laser therapy as a safe and effective minimally-invasive treatment option.

Midterm varicose vein recurrence rates after endovenous laser ablation: comparison of radial fibre and bare fibre tips

OBJECTIVES We evaluated and compared midterm recurrence results of our patients with great saphenous vein insufficiency who were treated with a 1470-nm diode laser using 2 different types of fibre catheter kits. METHODS A total of 61 consecutive patients were treated between 2013 and 2014 with a bare fibre (BF) tip (BF group) and 60 consecutive patients were treated with a radial fibre (RF) tip (RF group) from 2014 to 2016. First-year venous clinical severity scores (VCSSs) were compared with VCSS before endovenous laser ablation and at the first-month follow-up. Patients were examined for recurrence and classified according to the system developed by Stonebridge. RESULTS There was no significant difference between the 2 groups in terms of VCSS. Examination with Doppler ultrasonography showed no recurrence in the RF group, whereas recurrences were detected in 6 patients in the BF group, which was statistically significant (P = 0.028). All of the recurrences were type 1b (incompetent tributaries) varicose vein recurrences. The VCSS of the patients with recurrence were the same as the scores of patients without recurrence (0.5 ± 0.55). CONCLUSIONS Varicose vein recurrence was more often seen in the BF group than in the RF group. Recanalization-induced and neovascularization-induced recurrences were not found in either group. Saphenofemoral side branch-induced recurrence was more significant in the group treated with the BF tip.

Transformer Oil Ageing Detection using Mach–Zender Interferometry Configuration as a Sensor

Paper In this paper, the fabrication and characterisation of an optical fibre sensor for transformer oil ageing detection are presented. Bare fibre is used in the Mach–Zender interferometry (MZI) configuration as a sensing arm. Hydrofluoric acid (30%) and a power meter are used in sensor fabrication. The MZI sensor is affected by the changes of the refractive index (RI) of the transformer oil. The sensor operates according to different output power levels at the receiving end of the optical sensor. Results agree with the AC breakdown voltage test and oil absorption spectrum test. This work contributes to the improvement of transformer oil monitoring systems by ensuring the availability of oil information and protecting such systems from damage

Endovenous laser ablation of great saphenous veins using a 1470 nm diode laser and the radial fibre – follow-up after six months

Background Endovenous laser ablation (EVLA) is an efficient method to treat insufficient great saphenous veins (GSV) with high occlusion rates.1–5 Most studies used 810, 940 or 980 nm diode lasers and a bare fibre.1,2,6 Moderate postoperative pain and bruising are frequent findings.2,6 Laser systems with higher wavelengths like 1470 nm with a higher absorption in water show less pain and bruising after the procedure.7–9 A newly-developed fibre (radial fibre, Biolitec) emits the laser energy radially around the tip directly into the venous wall contrary to the bare fibre.9 The aim of this study was to demonstrate the outcome and side-effects after EVLA of GSV with a 1470 nm diode laser (Ceralas E, Biolitec) by using the radial fibre. Methods Non-randomized, prospective study including 50 unselected limbs of 50 patients with a duplex sonographically verified incompetent GSV. EVLA was performed with a 1470 nm diode laser (Ceralas E, Biolitec) and a radial fibre. In the same session all insufficient tributaries were treated by phlebectomy. Tumescent local anaesthesia with 0.05% lidocaine was applied perivenously. Laser treatment was carried out in a continuous mode with a power of 15 W. Compression stockings (30 mmHg) were applied for one month. Postinterventional checkups took place one, 10, 30 days and six months after the procedure. Results Three patients were lost to follow-up. The average linear endovenous energy density (LEED) was 90.8 J/cm vein (SD 35.3). At the six month follow-up all treated veins remained occluded and no new reflux in the treated segments occurred. No recurrent varicose veins had occurred so far. No severe complications such as deep venous thrombosis could be detected. In four patients at 30 days and three patients at six months local paresthesia occurred in the region of EVLA. Forty-four percent of patients did not have any pain after the treatment and 50% did not take any analgesic tablets at any time after the procedure. Postoperative ecchymoses in the track of the treated GSV was rare. In 80% of the limbs, no ecchymoses was observed after the treatment. Conclusion EVLA of GSV with a radially emitting laser fibre by using a 1470 nm diode laser is a safe and efficient treatment option.

The Microstructure Evolution in Fused Region and Taper Region of Fibre Coupler

The fused region and the taper region of the optical fibre coupler were tested by atomic force microscopy (AFM) and scanning electron microscopy (SEM), respectively. The results indicated that the surface roughness increased after fused biconical taper (FBT), that is, the fused region possessed the highest toughness (about 70nm), the taper region is in a second position (about 40nm), and the bare fibre was relatively the lowest (about 10nm). Micro crystals were observed at the fused region and the amount of the micro crystals decreased with increasing the drawing speed. Micro cracks were observed at the taper region and the micro cracks became wide and deep with increasing the drawing speed. All these changes affected not only the optical performance such as excess loss and consistence, but also the reliability and stability. Therefore a fibre device with high quality required small drawbacks.