Journal of clinical laser medicine & surgery最新文献

Objective: In order to achieve an accurate intraoperative ECG detection, a new technique in detecting the trigger-signal was developed. In contrast to the traditional three-lead ECG-configuration, the left leg electrode was connected to a transient epicardial pacemaker electrode on the left-ventricular surface.

Background data: The Holmium:YAG-Laser for Transmyocardial Laser Revascularization (TMLR) is R-wave-triggered, providing the release of energy only during the refractory period of the heart cycle. However, an exact ECG-triggering during mobilization of the apex and/or posterior wall is difficult to achieve by using conventional ECG-configuration, therefore increasing the risk for mistriggering and induction of arrhythmias during TMLR.

Materials and methods: Two groups of patients, all undergoing stand alone TMLR-procedures via left minithoracotomy, were compared. Ten patients were operated with the conventional ECG configuration (group 1) and ten patients with the modified epicardial ECG configuration (group 2).

Results: In patients of group 1, as a result of a loss of the trigger signal or due to the triggering of artifacts, the incidence of correctly triggered QRS-complexes was 56% of all documented QRS-complexes. In contrast, an excellent triggering was observed in 98% (p < 0.001) in group 2, resulting in a reduction of laser operative time by 35% (p < 0.001) and a decrease in the incidence of intraoperative ventricular fibrillation (0 vs. 3).

Conclusion: In conclusion, this new ECG configuration is a simple but effective method in achieving an excellent ECG signal during all stages of TMLR. As a consequence, a reduction in operative time and incidence of ventricular fibrillation can be achieved.

Objective: The purpose of this study was to determine the clinical usefulness of Er:YAG laser for cavity preparation in children.

Background data: The conventional methods for cavity preparation instill fear and discomfort in pediatric patients. The Er:YAG laser is a new tool developed for cavity preparation; however, there are few reports of its clinical application.

Materials and methods: A clinical evaluation using an Er:YAG laser was carried out using 32 subjects (with 16 deciduous and 19 permanent teeth) with ages ranging from 2 to 12 years. All cavities were restored with light-cured composite resin following the application of bonding agent, but without acid etching or primer conditioning.

Results: During laser treatment, the pediatric patients were very cooperative and hardly complained of any pain, and no tooth showed undesirable effects during the 3-year period of observation.

Conclusion: It can be concluded from the results of this study that an Er:YAG laser would be a useful alternative method for cavity preparation for composite resin restoration in children.

Objective: The aim of our study was to follow-up 15 patients with stretch marks treated positively with the CuBr laser (577-511 nm) in 1998-99 and followed-up for 2 years.

Materials and methods: The patients were Italian women, young to middle age (average 30 years old), with skin coloration classified as Fitzpatrick II-III. Biopsies were taken on some patients before the treatment and 1 month after the first treatment. Double-blind histological, histochemical and photographic evaluation was performed. Results obtained as well as to the contradictory effects reported elsewhere in the literature were compared.

Results: On average, the results were positive and there were some pathogenic considerations that justified the use of laser.

Objective: The purpose of this study was to assess the changes in gene expression of near-infrared light therapy in a model of impaired wound healing.

Background data: Light-Emitting Diodes (LED), originally developed for NASA plant growth experiments in space, show promise for delivering light deep into tissues of the body to promote wound healing and human tissue growth. In this paper we present the effects of LED treatment on wounds in a genetically diabetic mouse model.

Materials and methods: Polyvinyl acetal (PVA) sponges were subcutaneously implanted in the dorsum of BKS.Cg-m +/+ Lepr(db) mice. LED treatments were given once daily, and at the sacrifice day, the sponges, incision line and skin over the sponges were harvested and used for RNA extraction. The RNA was subsequently analyzed by cDNA array.

Results: Our studies have revealed certain tissue regenerating genes that were significantly upregulated upon LED treatment when compared to the untreated sample. Integrins, laminin, gap junction proteins, and kinesin superfamily motor proteins are some of the genes involved during regeneration process. These are some of the genes that were identified upon gene array experiments with RNA isolated from sponges from the wound site in mouse with LED treatment.

Conclusion: We believe that the use of NASA light-emitting diodes (LED) for light therapy will greatly enhance the natural wound healing process, and more quickly return the patient to a preinjury/illness level of activity. This work is supported and managed through the Defense Advanced Research Projects Agency (DARPA) and NASA Marshall Space Flight Center-SBIR Program.

Objective: The purpose of the present study was to discover new minimal invasive treatments of discogenic thoracic pain caused by protrusions or extrusions using the promising method of nonendoscopic Nd-YAG 1064 nm PLDN in the lumbar and cervical regions. Because early symptoms of chronic thoracic discogenic pain syndromes have not been characterized, interventional therapy is usually started late and involves a high complication rate.

Materials and methods: A prospective controlled clinical study was undertaken by neurologists using Nd-YAG 1064 nm PLDN to treat 42 patients with thoracic disc protrusions and extrusions. Patients with discogenic pain syndromes and MRI-confirmed disc pathology with spinal canal impairment were enrolled; 68 discs were treated. Maximal Nd-YAG laser 1064 nm dose was 1,000 watts per segment. Disc puncture was performed by dorsolateral approach. Monitored parameters were VAS, McNab score, subjective condition, neurological findings and peripheral EMG. A different, independent neurologist examined each case before and after surgery.

Results: At 6 weeks after treatment, 41 patients had a successful outcome; only one with a clinical suspicion of spondylodiscitis was dissatisfied. In all others, clinical parameters improved. EMG leaks had disappeared. Combined spastic paresis improved in 2/4 cases. Complications were one pneumothorax, one pleuritis and one suspected spondylodiscitis.

Conclusion: Pain relief and decompression of spinal structures is effective and immediate by disc vaporization, shrinkage, nociceptor destruction and discogenic kinius denaturation. Nonendoscopic percutaneous Nd-YAG 1064 nm PLDN is a highly effective method for the treatment of thoracic disc disorders with minimally invasive access and is recommended prior to any open surgery.

Objective: The purpose of the present study was to evaluate the effectiveness of Er:YAG laser irradiation for preparation of root canal orifices in extracted human teeth and several clinical cases.

Background data: Few studies with sufficient data have been conducted in this area.

Materials and methods: Orifices of 42 extracted human teeth were prepared by conventional methods using a Peeso reamer or Er:YAG laser device at 250 mJ/pulse and 8 Hz. In the clinical study, the orifices of 11 teeth from 11 patients with irreversible pulpitis were prepared by Er:YAG laser irradiation at 160 mJ/pulse and 8 Hz. Teeth were carefully irradiated using non-contact methods. Evaluation was performed by visual inspection, stereoscopy, radiography, and scanning electron microscopy (SEM). In addition, the efficiency of using the Er:YAG laser was evaluated.

Results: In the in vitro study, canal orifices were clearly exposed by laser irradiation in all specimens. In 31 of 36 teeth (86%), orifices were successfully prepared without ledge formation or perforation. SEM observations revealed that irradiated surfaces were slightly rough and scaly, but essentially free from debris and smear layer. In the clinical study, orifices were successfully prepared in 10 of 11 teeth (91%), and no ledge formation or perforation was observed.

Conclusion: These results suggest that the preparation of root canal orifices by Er:YAG laser irradiation may be useful in most cases, if appropriate parameters are selected.

Background data and objective: Surgery for recurrent sinusitis with diffuse polyposis is challenging since tortuous sinus anatomy and bleeding tendency can make revision surgery particularly difficult. We report the efficacy in using KTP laser under the assistance of endoscope to perform sinus clear-out procedure for patients with recurrent ethmoid polyposis.

Materials and methods: Thirteen patients with recurrent ethmoid polyposis underwent this procedure between November 1996 and July 2000. All were available for follow-up. Patients all had a KTP sinus clear-out procedure (15-20 W continuous mode, spot size 0.4-0.8 mm, contact or near-contact approaches) assisted by endoscope. Sinus endoscopic findings, CAT scan data, operation records and perioperative courses were retrospectively reviewed. The mean follow-up period was 24.7 +/- 11 months.

Results: Surgeries all went smoothly with minimal bleeding incurred. All patients demonstrated significant improvement in their sinonasal symptoms. Two cases (15.4%) had localized recurrent polyps.

Conclusion: With its excellent capabilities in hemostasis, great intra-nasal maneuverability, and flexible operation modes, KTP laser is an ideal alternative to manage recurrent ethmoid polyposis for selected cases.

Objective: The present study had the aim of evaluating the influence of different frequencies of the Er:YAG laser on adhesive resistance of enamel and one restorative system.

Background data: There have been no reports of studies assessing the influence of the pulse frequency variation of the Er:YAG laser on adhesive resistance of the enamel/resin interface.

Materials and methods: Fifty surfaces of enamel from extracted human third molars were planed and divided into five groups at random. Enamel surface treatment was realized by the Er:YAG laser at 80-mJ power and 1-, 2-, 3-, and 4-Hz pulse frequencies, followed by etching. For the control group, only acid conditioning with 37% phosphoric acid for 15 sec was used. The Single Bond/Filtek Z250 system was chosen for the fabrication of the specimens, which were stored in 100% relative humidity for 24 h, at 37 degrees C. The specimens were submitted to tensile resistance tests using a Universal Testing Machine (50 Kgf and 0.5 mm/min).

Results: The mean values in MPa were 1 Hz, 25.58 (+/-6.16); 2 Hz, 25.58 (+/-3.79); 3 Hz, 21.34 (+/-3.78); 4 Hz, 21.17 (+/-3.13); and phosphoric acid only, 22.44 (+/-7.0). Data were submitted to statistical analysis using ANOVA, and there was no significant difference in tensile resistance between the studied groups.

Conclusion: The results suggest that the Er:YAG laser, with 80-mJ power associated with acid conditioning at 1-, 2-, 3-, and 4-Hz frequencies, did not present significant improvement in tensile bonding of enamel, as compared to acid conditioning only.