BACKGROUNDTherapeutic approaches for tracheal stenosis caused by the formation of exuberant granulation tissues usually include electrocautery, mechanical dilation, laser therapy, argon plasma coagulation (APC), cryotherapy and stent placement. However, restenosis after stent insertion remains a significant limitation. We examined the efficacy of three different approaches, including induction of mechanical lesions, APC performed with different powers or durations and cryotherapy, to identify the method that limited the formation of granulation tissue.

METHODSTwelve specially bred research mongrel dogs were divided into three groups. In group 1 (four dogs) mild (procedure 1; two dogs) or moderate (procedure 2; two dogs) damage was induced mechanically. Group 2 (six dogs) received APC at different powers or durations (procedure 3: 30 W, 1 cm/s; procedure 4: 30 W, 2 cm/s; procedure 5: 25 W, 3 cm/s). Group 3 (two dogs) received cryotherapy (procedure 6: two freeze-thaw cycles of 30 seconds). Uncovered self-expandable metallic stents were inserted in all dogs to maintain a continuous stimulus to the trachea mucosa. Dogs were monitored for 4 weeks and the relationship between granulation tissue proliferation and method used was analyzed.

RESULTSIn group 1, granulation tissue growth increased with more severe mechanical damage. The growth of granulation tissue in group 2 was more pronounced than in group 1, and both dogs in procedure 3 died because of severe stenosis. In this group, the formation of granulation tissue decreased with decreasing power and duration. In group 3, no obvious granulation tissue was found at week 4.

CONCLUSIONSLesions and stimuli from a foreign body (the stent) are two important factors that lead to overgrowth of granulation tissue. Thermal lesions, such as APC, seem to induce greater granulation tissue growth and cartilage damage compared with mechanical and cryotherapy lesions. Cryotherapy in combination with mechanical dilation may be a safe and effective treatment method for managing tracheal stenosis caused by the formation of granulation tissue.

Animals ; Bronchoscopy ; methods ; Cryotherapy ; Dogs ; Granulation Tissue ; pathology ; Laser Coagulation ; methods ; Stents ; Tracheal Stenosis ; therapy

AIMTo study the histologic changes of the vas deferens following Nd: YAG laser irradiation.

METHODSIntravasal laser irradiation was given to (i) 52 segments of rabbit (laser dosage: 2 seconds at 40 W approximately 50 W) and 16 segments of human (3 seconds at 45 W approximately 55 W) vas deferens in vitro, (ii) 25 rabbit vasa (2 seconds approximately 2.5 seconds at 40 W approximately 45 W) in vivo and (iii) 2 human vasa (3 seconds at 55 W) in vivo. Segments of vasa were removed from the in vivo irradiated vasa deferentia 15 days approximately 180 days (rabbit) or 15 days (man) after the exposure. All vas segments were embedded in methacrylate resin. Serial sections (thickness 25 microm approximately 30 microm) were obtained and observed under a light microscope.

RESULTS(i) Laser-induced damage reached the muscularis layer in 27% and 94% of the rabbit and human vas segments in vitro, respectively. (ii) Fourteen of the 25 in vivo rabbit vasa were completely occluded by fibrous tissue and the longer the time interval after treatment, the more likely was the vas occluded. Those unoccluded vasa had either a normal histology or a mucosal damage. (iii) One in vivo human vas was almost completely occluded by the fibrous tissue but the other had a relatively large lumen packed with sperm granulomatous tissue and partial destruction of the smooth muscle layer.

CONCLUSIONLaser irradiation can induce long-term vas occlusion; for rapid occlusion, laser doses just completely destroying the mucosal layer will be advisable.

Animals ; Humans ; Laser Coagulation ; Male ; Rabbits ; Sterilization, Reproductive ; methods ; Vas Deferens ; anatomy & histology ; Vasectomy

OBJECTIVETo seek a safe, efficient, and cost-effective technique for local thermo-ablation of hepatic cancer.

METHODSThe livers from 16 healthy rabbits were thermocoagulated by diode-laser with scanner fiber tip, 6 w for 10 mins. At the same time, the temperatures were measured at 0, 5 and 10 mm from laser tip. The pre-thermocoagulative liver function was compared with that of 7 days post-thermocoagulation. The pathologic changes were also observed 1 month after laser thermocoagulation.

RESULTSAll the rabbits survived and hepatic tissue temperatures at 0, 5, 10 mm from laser tip reached 96.39 degrees C +/- 3.97 degrees C, 60.79 degrees C +/- 6.21 degrees C, 46.10 degrees C +/- 4.58 degrees C respectively after 10 minutes of thermocoagulation. There were no significant differences in liver function parameters between rabbits of pre-laser thermocoagulation and of post-laser thermocoagulation. Thermocoagulated necrosis of liver tissue with surrounding fibrosis in a diameter of 26.0 mm was formed. Light microscopy revealed coagulative necrosis in the center of the coagulated area without surviving hepatic cells.

CONCLUSIONThe hepatic tissue can be coagulated safely and effectively by diode-laser with scanner fibertip, and such a technique may provide a new method for the treatment of hepatic carcinoma.

Animals ; Female ; Laser Coagulation ; methods ; Liver Neoplasms ; pathology ; surgery ; Male ; Rabbits

OBJECTIVETo study the effect of Ar(+) laser on human vas deferens and to compare the effects of using different radiation levels with varying thickness of tissue and varying levels of injury.

METHODSAfter initial tests on animals, four human scrotums were opened and treated directly with Ar(+) laser radiation. Then 58 human individual scrotums were treated with radiation by the method of trans-skin puncture. The rate of sperm reduction and elimination was tested.

RESULTSIn 60 cases, the sperms were found to be eliminated completely after six months of radiation treatment. In 2 cases the sperms were found not to be eliminated completely due to the insufficient radiation.

CONCLUSIONAr(+) laser is one of the best forms of radiation for coagulation of vas deferens. It can be used to coagulate vas deferens without any complications or sequelae.

Adult ; Follow-Up Studies ; Humans ; Laser Coagulation ; Male ; Sterilization, Reproductive ; methods ; Vas Deferens ; surgery

OBJECTIVETo retrospectively analyze the experiences and results of the treatment on 62 patients with primary varicose of lower extremities with endovenous laser.

METHODSAll patients were treated with endovenous laser. The laser treatment could begin when the fiber withdraw with 1 cm/2 s. The laser power was 10 - 12 w with the laser pulse duration and the interval 1 second respectively.

RESULTSThe duration of follow-up varied from 2 months to 8 months. After endovenous treatment, the varicose veins and edema disappeared in all cases. The itching and uncomfortable feeling was dissipated. No morphine-like analgesic has been used and no serious complications occurred.

CONCLUSIONEndovenous laser treatment of primary varicose of lower extremities is a safe and effective technique.

Female ; Follow-Up Studies ; Humans ; Laser Coagulation ; methods ; Male ; Retrospective Studies ; Treatment Outcome ; Varicose Veins ; surgery

Argon ; Gastric Antral Vascular Ectasia ; physiopathology ; therapy ; Humans ; Laser Coagulation ; methods ; Male ; Middle Aged

BACKGROUNDLarge drusen is a known risk factor for the development of late complications of age-related macular degeneration (AMD) and drusen reduction has been found by our previous study. To prospectively evaluate the efficacy and safety of prophylactic laser treatment in Chinese patients with bilateral soft drusen, we examined the structure and function of the macula 8 years after treatment.

METHODSTen patients with more than 10 soft drusen (> 125 mm) and best corrected visual acuity ≥ 20/25 in each eye participated in the study. One eye, with relatively more drusen, was exposed to an argon laser (514 nm) to achieve a barely visible retinal lesion. The contralateral eye was used as a control. Fluorescein angiography, Amsler tests, Fourier-domain optical coherence tomography and visual evoked potential tests were carried out 8 years later.

RESULTSNo choroidal neovascularization was seen in the laser-treated eyes or control eyes. There were no significant differences in visual acuity or P100 latency and amplitude between the laser treated eyes and contralateral eyes (t = 1.685, 1.184; P > 0.05). The thickness of the retinal pigment epithelium of the treated eyes was less than that of the contralateral eyes (t = -4.540; P < 0.05). The full retinal thickness in treated eyes was slightly, but insignificantly, reduced relative to contralateral eyes (t = -1.746; P > 0.05).

CONCLUSIONSThe treatment was associated with a reduction in retinal pigment epithelium thickness elevation compared with the contralateral eyes. Macular function was not impaired.

Aged ; Aged, 80 and over ; Female ; Humans ; Laser Coagulation ; methods ; Male ; Middle Aged ; Retinal Drusen ; surgery ; Wet Macular Degeneration ; surgery

The treatment of congenital vascular malformations is still a difficult problem. Minimally invasive surgical treatments such as sclerotherapy, embolizations, and laser treatments have become increasingly applied. Arteriovenous malformations are treated by transcatheter endovascular selective arterial embolizations, venous malformations by sclerotherapy, Nd: YAG laser, and DIOMED laser treatments, and Klippel-Trenaunay syndrome by endovenous DIOMED laser treatments. Most patients with congenital vascular malformations obtain good clinical outcomes after minimally invasive surgeries, although their long-term efficacy requires further investigation.
Arteriovenous Malformations ; therapy ; Embolization, Therapeutic ; methods ; Humans ; Klippel-Trenaunay-Weber Syndrome ; congenital ; therapy ; Laser Coagulation ; methods ; Minimally Invasive Surgical Procedures ; Sclerotherapy ; methods ; Veins ; abnormalities ; surgery

OBJECTIVETo evaluate the therapeutic effect of laser photocoagulation of ciliary processes after pars plana vitrectomy in aphakic glaucoma.

METHODSTwenty patients (20 eyes) of aphakic glaucoma underwent vitrectomy plus laser treatment. During the surgery, after conventional 3-incision pars plana vitrectomy, a probe of semi-conductor diode laser (532 nm) was inserted through the sclera incision, the ciliary processes were then photocoagulated under direct visualization for 180 degree range. Before and after the surgery, the visual acuity, the intraocular pressure (IOP) as well as the outer appearance of the anterior segment were evaluated. The mean follow-up period was 13 months.

RESULTSThe IOP at the last visit was (21.35 +/-2.52) mmHg, which was significantly lower than that before the surgery [(39.75 +/-6.27) mmHg, P=0.000]. Atrophy of the ciliary processes was observed 1-3 months after the surgery.

CONCLUSIONPars plana vitrectomy combined with laser coagulation of ciliary processes reduces the IOP in patients with aphakic glaucoma effectively.

Adult ; Aphakia ; complications ; Ciliary Body ; surgery ; Female ; Glaucoma ; complications ; physiopathology ; surgery ; Humans ; Intraocular Pressure ; Laser Coagulation ; methods ; Male ; Middle Aged ; Treatment Outcome ; Visual Acuity ; Vitrectomy ; methods

PURPOSE: To evaluate the safety and efficacy of fractional photothermolysis (FP) in the treatment of facial wrinkles in Asians. METHODS: A total of 27 Korean patients (Fitzpatrick type III or IV) received 2-3 FP treatment sessions (Sellas; Dinona Inc., Seoul, Korea) spaced two weeks apart. Treatments were performed at settings of 7 to 9 mJ/microthermal treatment zone (MTZ) and a density of 1000 MTZ/cm2. Standardized digital photographs were obtained before each treatment and three months after the final treatment. The evaluations of clinical photographs were performed by three physicians blinded to the study subjects using a five-point grading scale. In addition, the patients' perceived degree of improvement was assessed three months after the final treatment using a five-point grading scale. Side effects were monitored at each follow-up visit. RESULTS: The physicians' assessed degrees of improvement were excellent in three patients (12%), significant in ten (40%), and moderate in seven (28%). The patients' self-assessed degrees of improvement were excellent in five patients (20%), significant in 11 (44%), and moderate in six (24%). Adverse events were limited to transient pain, erythema and edema, except in one case of transient postinflammatory hyperpigmentation. CONCLUSIONS: FP is an effective treatment modality for reducing facial wrinkles with minimal side effects in Asian patients.
Adult ; *Cosmetic Techniques ; *Face ; Female ; Follow-Up Studies ; Humans ; Korea ; Laser Coagulation/*methods ; Male ; Middle Aged ; Phototherapy/*methods ; Prospective Studies ; *Skin Aging