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At least 613 records · Page 34Linked to original sources
PubMed1988

Functional and histological restitution in the urinary tract after Nd:YAG laser coagulation.

Current development in endourologic equipment has made possible the endoscopic application of the Nd:YAG laser in the treatment of urothelial tumors of the whole urinary tract. The clinical results are rather promising. We controlled with various methods the healing processes of 14 rabbit ureters after Nd:YAG laser treatment as to morphological repair and physiological function. The ureters were irradiated transrenally with an energy of 60 J coagulating all wall layers. Healing of the laser lesions nearly to normal in all animals was observed 4 to 6 weeks after treatment. The prevailing histological and physiological changes in the ureter are extremely slight and do not disturb the normal ureteral function. The results show the complete healing process of the ureter after laser coagulation and make the application of Nd:YAG laser in the upper urinary tract much more predictable.

Animals↗
PubMed1988

Effects of laser wavelengths on experimental retinal detachments and retinal vessels.

We studied the effects of the yellow (577 nm), orange (595 nm) and red (630 nm) dye lasers, the argon blue-green (488, 514.5 nm) and green (514.5 nm) lasers, and the krypton red (647 nm) laser on experimentally produced serous and hemorrhagic retinal detachments and on retinal vessels in rabbits. Retinal detachments were created by either injecting balanced saline solution or partially hemolyzed blood under the retina. All laser wavelengths except the argon blue-green bypassed the sensory retina and produced no damage on either the sensory retina or the underlying retinal pigment epithelium with serous retinal detachment. Each laser wavelength, however, produced a specific effect on the detached retina with hemorrhagic fluid. Blue-green, green, yellow and orange wavelengths damaged the sensory retina more severely than the red wavelengths. Laser coagulation of the retinal vessels with the blue-green, green and orange wavelengths produced vasospasms.

Animals↗
PubMed2006

A new minimally invasive technique for treating radiation cystitis: the argon-beam coagulator.

OBJECTIVE: To assess the effectiveness of the argon-beam coagulator used endoscopically for treating radiation cystitis, as radiotherapy is commonly used for treating pelvic tumours of urological origin, but intractable bleeding related to radiation cystitis remains a serious complication and requires a difficult long-term follow-up, for which cystoscopic methods of management have traditionally had limited success. PATIENTS AND METHODS: We assessed seven patients with radiation cystitis; they were treated with argon-beam coagulation after a cystoscopic evaluation. RESULTS: With a mean follow-up of 15 months, one treatment was used in six patients, with a second treatment required in one. CONCLUSION: The argon-beam coagulator appears to be a safe, well tolerated and minimally invasive treatment in patients with radiation cystitis.

Argon↗
PubMed1990

Intraocular pressure following peritomy and wet-field coagulation.

The changes in intraocular pressure (IOP) following peritomy and wet-field coagulation of 10 rabbit eyes and 7 human cataractous eyes were investigated. The IOP difference before and after 180-degree and 360-degree wet-field coagulation on rabbit eyes showed an average increase of 11.0 +/- 5.8 mmHg and 25.8 +/- 7.1 mmHg(mean +/- SD), respectively (p less than 0.05, p less than 0.01). The IOP of both groups in rabbit eyes were elevated for 2 to 3 days postoperatively and then became normal by the 7th postoperative day. The IOP difference before and after 180-degree peritomy and wet-field coagulation in human cataractous eyes showed an average increase of 8.4 +/- 5.8 mmHg(mean +/- SD)(p less than 0.05). The outflow facility was poor immediately following wet-field coagulation but then improved gradually by means of tonography and concentration changes of anterior chamber neutral-red. Histologically, there was endothelial cell damage, congestion, and red blood cell extravasation of the episcleral and intrascleral vessels at one day after wet-field coagulation in the light microscopic findings. Recanalization of the episcleral and intrascleral capillaries was noted 3 days after wet-field coagulation and was completed 3 weeks after wet-field coagulation. There was poor plastic infusion through the trabecular spaces in the one-day postoperative group compared to the control group by scanning electron micrograph. In conclusion, we have to bear in mind the possibility of an IOP rise after wet-field coagulation following peritomy for cataract and retinal surgery.

Animals↗
PubMed1977

[Modern trends in the treatment of diabetic retinopathy (author's transl)].

Adequate control of diabetic patients may not only delay the appearance of diabetic retinopathy, but may, moreover, effect the regression of fundus changes at the pre-retinopathic stage and in cases of commencing non-proliferative retinopathy. Medical treatment is based on the achievement of a decrease in vascular permeability and a lowering of the blood lipid level; a diet enriched with phosphates may influence retinal hypoxia by increasing the 2,3 diphosphoglycerate level in the erythrocytes, thereby leading to an improved free oxygen supply to the tissue. Complete medical and dietetic compensation of hyper-permeability of the retinal capillaries, of the intraretinal exudation of lipoproteins, and of retinal hypoxia belong still today to utopia; hence, conservative treatment is only of auxiliary character. Hypophysectomy has largely been abandoned in view of the mutilation involved and the poor results of this procedure. The most effective active treatment is photocoagulation. The best results are obtained by a combination of generalized unselective coagulation of the peripheral retina by means of a xenon coagulator and the selective elimination of progressive vascular changes seen in the fluorescein angiogram with argon laser.

Capillary Permeability↗
PubMed1985

[Changes in uveal melanoblastomas during therapeutic photocoagulation].

Investigation of 121 uveal melanomas revealed three stages of postcoagulation changes: destruction connected with the immediate coagulating effect of the radiation (from 1 to 14 days after coagulation); inflammation and destruction changes displaying the antitumour immune response and accompanied by the increased functional activity of the survived melanoma cells (from 2 weeks till 2-4 months); fibrotization of the most damaged parts of melanoma tissue and structural and functional reorganization of some melanoma cells with the signs of their greater atypia. Melanomas of different cell type composition react to coagulation differently, this is manifested by the intensity, duration and reversibility of functional changes of tumour cells and also by the probability of their greater atypia.

Humans↗
PubMed1990

Continuous laser radiation effect at 1.06 microns on gastrointestinal tract.

The thermal effect of 1.06 microns YAG:Nd laser irradiation at temperature conditions up to 100 degrees C without crater formation on gastrointestinal (GI) tissue samples was investigated. The theoretical and experimental data show that at an intensity of 160-400 W/cm2 laser-induced heating of the tissue with an initial temperature of 20 degrees C leads to coagulation lesions at a temperature no less than 60 degrees C and at a depth of 1.7-2.1 mm.

Colon↗
PubMed1978

[Retinal circulation time in diabetic retinopathy treated with photocoagulation (author's transl)].

A preliminary report is given on studies of the retinal circulation in diabetic retinopathy before and after photocoagulation treatment. The local retinal circulation time RCT of selected retinal areas was calculated by means of a fluorescein long-term infusion technique. In 7 eyes with diabetic retinopathy (DR) the mean RCT was significantly higher (2.0 +/- 0.58 sec. range 1.27-2.6) than in 15 control eyes (1.11 +/- 0.34 sec, range 0.50-1.82, Niesel 1976). Assuming an increase of blood flow in DR (L'Esperance 1971, Kohner 1975) the increase of RCT by a factor 2 would imply an increase of the vascular volume by a factor hardly less than 3 indicating the marked impairment of retinal hemodynamics in DR. After photocoagulation, the mean RCT was significantly shortened only in eyes with preoperative RCT values above 2 sec. The reduction of local RCT correlated with the extent of treated retinal areas. The cross-sectional area of the retinal veins measured near the optic disc was generally reduced independently of the extent of coagulation treatment. Taking also the obvious postoperative reduction of the total retinal vascular volume into account, photocoagulation resulted in a marked decrease of blood flow not only in extensively treated but also in areas with little coagulation effects. In DR the disturbed retinal circulation in general tends to normalize following extensive photocoagulation.

Blood Volume↗
PubMed1994

[Alternative therapeutic methods in the ambulatory treatment of hemorrhoids: observations with infrared coagulation].

The author reports his observations gained by different ambulatory treatments of haemorrhoids. A total of 1537 patients with different degree internal haemorrhoids were randomly treated by rubber band ligation, sclero cryo therapy and infrared coagulation. The five years results and review of international literature suggest that infrared coagulation among the known procedures its proper application is economic, suitable and alternative possibility in the treatment of haemorrhoids.

Ambulatory Care↗
PubMed1988

Laser probe coagulation of bleeding canine ulcers.

A nonlight-transmitting contact laser probe was used to treat acutely bleeding gastric ulcers in heparinized dogs. Thirty-five treated ulcers responded with complete hemostasis following 21-92 seconds (mean, 32 seconds) application per ulcer. Ten control ulcers left untreated bled for 5-30 minutes (mean, 11 minutes). Hemostasis was maintained at treated sites for the entire observation period (60 minutes). Perforations did not occur, and there was no evidence of full thickness injury. Histological assessment confirmed a limited (0.2-0.5 mm) zone of coagulation injury. The laser probe is effective for control of acute bleeding in this canine ulcer model.

Animals↗
PubMedDate not supplied

Vaginal and cervical cytologic changes following laser treatment.

Carbon dioxide laser treatment is a very effective mode of removal of small fragments of tissue from the cervix which causes minimal bleeding and trauma and is followed by rapid healing. Biopsy sections and particularly cytologic preparations obtained from the areas of laser action indicate that squamous and columnar epithelial cells and possibly fibrocytes in the underlying connective tissue are altered, appearing coagulated and elongated similar to cells which have been removed from an area of electrocautery.

Adult↗
PubMed1991

Contact diode laser application through a fiberoptic cutting tip.

We applied diode laser energy through a fiberoptic probe to cut ocular structures. The diameter of the probe's tip was 100 microns. The amount of energy used for cutting the lid, the cornea, or for perforation of the glove was 2.5 watts in the continuous mode. The incised border demonstrated coagulation into the healthy tissue ranging from 10 to 50 microns.

Animals↗
PubMed1992

Interstitial laser photocoagulation: Nd:YAG 1064 nm optical fiber source compared to point heat source.

Interstitial laser photocoagulation (ILP) was performed in vitro in lean bovine and chicken muscle by delivering 1.6 W of continuous-wave Nd:YAG laser energy (1064 nm) from a 400-microns core optical fiber for 300s. The resulting thermal coagulation lesion was consistently larger when the delivered energy was deposited into a small steel sphere than when it was delivered freely into the tissue. Mathematical modelling confirms this result. This preliminary study suggests that a point heat source produces a larger volume of thermal coagulation than a point optical source (1064 nm) delivering the same power.

Animals↗
PubMed1990

Long-term results of treatment of vascular malformations of the gastrointestinal tract by neodymium YAG laser photocoagulation.

This study reports long-term results of treatment of vascular malformations of the gastrointestinal tract by neodymium YAG (Nd-YAG) laser photocoagulation in 60 patients (13 patients with hereditary hemorrhagic telangiectasia and 47 patients with angiodysplasias) and examines prognostic parameters of bleeding recurrence in 47 patients with angiodysplasias. In patients with hereditary hemorrhagic telangiectasia, the transfusion requirements were lower only in the second and third year following therapy than in the year before therapy; however, these differences were not significant. In patients with angiodysplasias, a median number of one laser session (range 1-8) was necessary to destroy angiodysplasias. A blood loss recurred in 15 patients. The cumulative probability of remaining free of blood loss recurrence at 24 months and at 54 months was 61 +/- 9%. Three parameters had an independent prognostic value, the initial number of angiodysplasias (P less than 0.02), the presence of coagulation disorders (P less than 0.05), and age (P less than 0.05).

Aged↗
PubMed1987

[Simultaneous fluo-angioscope. Image superposition for macular photocoagulation].

A new, compact optical instrument developed in clinical work is presented and its optical properties are discussed: it allows simultaneous viewing of a patient's fundus and its fluorescein angiography. Both stereo and mono angiography can be superimposed in the slit lamp in a 1-to-1 juxtaposition of fundus topography and angiogram. In this way very precise transfer of angiographical data is possible. Safety during laser coagulation is increased, and the size of iatrogenic scotomas is thus reduced. The instrument is described, and image superimposition illustrated with clinical examples.

Fluorescein Angiography↗
PubMed1999

The contribution of vitreoretinal surgery to the management of refractory glaucomas.

Vitreoretinal techniques, although not new, are only gradually being recognized in the management of refractive glaucoma. Besides rare but established indications for vitrectomy, as in malignant glaucoma, vitreoretinal surgery may become even more valuable by offering an alternative outflow route to the choroid that remains open and functional. Vitreoretinal surgery in neovascular glaucoma is primarily meant to be antivasoproliferative surgery. Vitrectomy-lensectomy accesses the eye for panretinal laser coagulation, the only effective treatment of ocular neovascularization so far. Vitrectomy is a way of interfering with the pathogenesis of ocular new vessel formation, which otherwise inevitably leads to phthisis.

Glaucoma, Neovascular↗