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At least 217 records · Page 12Linked to original sources
PubMed1994

[Laser coagulation treatment of urothelial tumors of the upper urogenital tract with the Nd:-YAG laser].

Six patients with upper urinary tract tumors were treated in our department with the Nd:-YAG laser between 1989 and 1993. The average follow-up was 23.8 months. The mean age of the patients was 65.7 years. The patients were selected for organ-conserving treatment because of bilateral synchronous tumors (2 cases), a solitary renal unit (2 cases), renal insufficiency with high surgical risk (1 case) and high surgical risk alone (1 case). Two patients were treated with open tumor excision and laser, two patients with ureteroscopic and percutaneous procedures one patient with percutaneous treatment and one patient with ureteroscopy. Two patients underwent nephroureterectomy; one of them died of metastatic bladder cancer 9 months later. Local relapses were observed in one patient who had been treated endoscopically. In a follow-up period of 6-36 months there were three patients who had no relapses. Three patients received intracavitary therapy. Kidney conserving procedures with the Nd:-YAG laser in patients with upper urinary tract tumors should be reserved for highly selected cases.

Aged↗
PubMed1993

Modeling the color perception of port wine stains and its relation to the depth of laser coagulated blood vessels.

To find the maximal depth of an ecstatic vessel in the dermis that contributes to the abnormal color of a port wine stain (PWS), "normal" and "laser treated PWS skin" are modeled, respectively, as a two-layer plane parallel geometry consisting of an epidermis and a dermis, and as a three-layer geometry consisting of an epidermis, a dermis without additional blood (the "treated" part of the stain, assumed identical to the "normal" dermis), and a layer of dermis containing 5% or 10% of blood per volume (the untreated part of the PWS). Spectral remittances were calculated for various wavelengths using the diffusion approximation to the transport equation for light propagation. These remittances were transformed into the CIE 1976 (L*a*b*)-color system. Color differences between "normal" and PWS skin as a function of the dermal depth of "injured" ecstatic blood vessels were calculated. The maximal depth where ecstatic blood vessels just contribute to the abnormal PWS color is predicted as 0.9 mm for a "normally" pigmented epidermis (60 microns thick) and a 5% or 10% blood per volume content. For a darker pigmented epidermis (60 microns thickness) and again at both 5% and 10% blood per volume content, this depth was found to be 0.8 mm.

Blood↗
PubMed2002

Inoperable adenocarcinoma of the oesophagogastric junction: a comparative clinical study of laser coagulation versus self-expanding metallic stents with special reference to cost analysis.

AIMS: Neither clinical nor financial comparisons yet exist between self-expanding metallic stents (SEMS) and laser therapy, concentrating on the treatment of obstructive adenocarcinomas of the oesophagogastric junction. The aim of our study was to compare the relative lifetime costs and clinical results of the Nd:YAG laser to those of SEMS as alternative forms of primary palliation of dysphagia for adenocarcinoma near the oesophagogastric junction. METHODS: Fifty-two patients with distal oesophageal or oesophagogastric adenocarcinomas underwent palliative treatment for dysphagia: 32 treated with laser therapy and 20 with SEMS in this retrospective study. The clinical outcome and real cumulative costs as physical units and in financial terms were analysed for these study groups. RESULTS: Although patients palliated with SEMS underwent fewer procedures (1.9+/-1.6 vs 3.4+/-4.0, P=0.0048) and spent less time in endoscopic theatre (38+/-25min vs 118+/-152min, P=0.0048), they spent as many days in hospital (12.9 vs 15.1, P=0.370) and required as high overall costs for therapy (5360 EUR vs 5450 EUR, P=0.679) as those treated with laser therapy. In addition, they had higher morbidity rates (30 vs 6.3%, P=0.043), hospital mortality (20 vs 3.1%, P=0.066), and 30-day mortality (40 vs 3.1%, P=0.0011) than did patients with laser therapy, with no evidence of SEMS being the more effective treatment modality. CONCLUSIONS: In patients with adenocarcinoma at the distal oesophagus or at the oesophagogastric junction, laser therapy palliates dysphagia effectively with lower morbidity and mortality rates and without increased costs or hospital stays than does use of self-expanding metallic stents.

Adenocarcinoma↗
PubMed2005

Incidence and impact of perioperative complications in 175 fetoscopy-guided laser coagulations of chorionic plate anastomoses in fetofetal transfusion syndrome before 26 weeks of gestation.

OBJECTIVE: The purpose of this study was to evaluate the perioperative complications in fetoscopy-guided laser therapy in fetofetal transfusion syndrome. STUDY DESIGN: Details of fetofetal transfusion syndrome cases who were delivered between 1999 and 2004 in a single center were reviewed retrospectively. RESULTS: One hundred seventy-five procedures were performed percutaneously with the use of local anesthesia. Survival at 6 months of at least 1, 1, and 2 babies was 73%, 38%, and 35%, respectively. Placental abruption and miscarriage was diagnosed in 3 and 12 cases, respectively. Premature rupture of membranes occurred in 49 cases (28%) and including 12, 29, and 46 cases that occurred before 24, 28, and 34 weeks of gestation, respectively. The entry of the trocar was transplacental in 48 cases (27%), but it was not associated with miscarriage (P = .26), premature rupture of membranes (P = .58), or placental abruption (P = .37). CONCLUSION: Fetoscopic laser treatment of fetofetal transfusion syndrome can be performed percutaneously with local anesthesia without significant maternal morbidity. Transplacental entry was not associated with premature rupture of membranes or miscarriage.

Chorion↗
PubMed1994

Comparison of Bipolar Electrocoagulation and Nd:YAG Laser Coagulation for Symptomatic Reduction of Uterine Myomas

In 1991 and 1992, we presented a review of our experience using Nd:YAG laser fiber and bipolar needles to coagulate uterine myomas laparoscopically. We now present a comparison study of the Nd:YAG laser vs. bipolar coagulation needles for laparoscopic reduction of symptomatic uterine myomas. Since October 1990, we have performed over 300 cases of laparoscopic coagulation of symptomatic uterine myomas. The technique includes reduction of uterine and myomata size using depot leuprolide for a three to four month period of time. Hysteroscopic examination and endometrial sampling is performed during this preoperative period. The Nd:YAG laser fiber is a 600 micron bare fiber combined with a 50 watt Nd:YAG laser. The bi-polar needle is made in 30 and 45 mm lengths. The needles measure 5 cm in length and are inserted through a 5.5-mm trocar. Coagulation effect is measured by a standard ammeter. Myoma shrinkage is measured by pre- and post-operative vaginal ultrasound examination. Results reveal additional shrinkage 50-70% beyond the leuprolide effect. No myoma regrowth has been noted in this 3 year period. Minimal follow-up was 12 months. For patients with significant uterine bleeding, endometrial ablation is carried out at the same time.

Journal Article↗
PubMed1983

Transurethral laser coagulation for treatment of urinary bladder tumors.

Owing to the biophysical properties involved, the Nd:YAG laser is most suited for coagulation of even inhomogeneous tissue. We determined the optimal laser parameters for therapy of urinary bladder tumors. Deep homogeneous necroses can be obtained without perforation risk of the bladder wall, and the procedure does not cause dangerous damage to the intestinal loops. We have studied animal experiments by close examination and systematic inquiry, and thus we were able to determine sufficient laser parameters in dependence on tissue thickness. Clinical studies verified these results for living human tissue. After some years of clinical use of the Nd:YAG laser we can make the first statistical statements.

Fiber Optic Technology↗
PubMedDate not supplied

Periocular skin reshaping by CO2 laser coagulation.

When blepharoplasty is performed by transconjunctival route, sometimes the excess of skin created by overlaxness of the lower lid does not retract to achieve the desired cosmetic result. We propose a method for controlled retraction of the eyelid by coagulating the skin using the CO2 laser. Thanks to this approach, the lower eyelid's tone recovers and the desired cosmetic appearance is achieved. Results of 37 patients that were treated by 10 W CO2 laser, 5-mm defocused beam diameter, and pulses of 100 ms, are presented. Follow-up shows that periocular skin reshaping by CO2 laser for laxened eyelid is a safe method and it can be considered a good alternative of treatment for blepharochalasis without skin excision.

Adult↗
PubMed1978

Laser-coagulation of ruptured fixation suture after lens-implantation.

Before it was known that polyamide tends to dissolve in tissue, nylon sutures were used to fixate 2-loop-Medallion-lenses to the iris. As was to be expected cases turned up in which the suture had ruptured. This situation entails the danger of contact between the end of the broken suture and the endothelium. By coagulation of the suture with a laser beam the danger was eliminated.

Corneal Injuries↗
PubMed1985

[Flattening of hypertrophic scars by punctiform argon ion laser coagulation in several sessions].

11 hypertrophic scars were treated by different argon ion laser techniques. The observation period is 0.5-3 years. Punctiform coagulation zones of 2-3 mm diameter, interspersed by untreated areas of scar tissue of 2 mm length, which are by lasered 6 weeks later in a second laser session, has proved most successful. Laser sessions are repeated in this manner until sufficient flattening of the hypertrophic scar is achieved. A low power density and very brief multiple interrupted radiation periods for controlling the thermal effect are useful. It is assumed that small superficial coagulation necroses produced by the argon ion laser will result in subsequent scar tissue being formed in other directions while decreasing the collagen formation, eventually resulting in flattening of the hypertrophic scar.

Adult↗
PubMed1998

[Acute retinal necrosis syndrome. Argon laser coagulation for prevention of rhegmatogenic retinal detachment].

BACKGROUND: ARN syndrome follows severeintraocular infection by herpes viruses and primarily affects the peripheral retina. Following scar formation, despite antiviral treatment, rhegmatogenous retinal detachment occurs very often. Prophylactic argon laser photocoagulation has therefore been proposed. We report our experience. PATIENTS: We treated five patients presenting clinically with advanced unilateral ARN with acyclovir. All eyes received a prophylactic confluent double row of argon laser treatment (500 microns, 0.2 s, gray-white lesions) central to the affected area as soon as was possible, depending on the vitreous clouding. Four patients were treated with Aspirin. RESULTS: One of the five patients had a peripheral rhegmatogenous retinal detachment that was limited by the argon laser row. Another patient had a tractional detachment needing vitreoretinal surgery. Two eyes developed vitreal hemorrhage of unknown origin. CONCLUSION: A lower rate of rhegmatogenous retinal detachments than expected occurred post-laser treatment. Vitreal hemorrhage was more frequent than previously reported. The bleeding probably originated from anterior retinal neovascularization and may have been enhanced by Aspirin treatment. We recommend early prophylactic argon laser photocoagulation in all ARN patients in agreement with the results of previous studies.

Acyclovir↗
PubMedDate not supplied

Postoperative MRI in patients undergoing interstitial laser coagulation thermotherapy of benign prostatic hyperplasia.

OBJECTIVE: We conducted MRI of the effects of laser-induced thermal therapy (LITT) in benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Eighteen patients (average age 64 years) were examined with MRI 24-48 h before and after LITT of BPH. Sagittal and axial T2-weighted FSE MR images were evaluated for signs of coagulation necrosis in the prostate gland and the presence of intra- and extraprostatic edema. RESULTS: Coagulation areas showed as a hypointense central core with a hyperintense rim. Intraprostatic edema led to a volume increase of 18-108% both in the central and in the total gland. Periprostatic edema was severe in preprostatic and prevesical tissue as well as lateral to the prostate, moderate in the presacral space, and mild perirectally and dorsal to the prostate. Follow-up examinations 2 weeks to 6 months after LITT in five patients showed decrease of coagulation necrosis volume, prostate size, and edema. CONCLUSION: MRI appears to be a reliable method to monitor LITT effects in patients with BPH.

Aged↗
PubMed1985

[Preclinical study of endoscopic laser coagulation of human ovaries].

The hemostatic potential of YAG laser irradiation was investigated in 21 hysterectomy and adnexectomy patients of childbearing age. Endoscopic forceps were used to induce hemorrhaging in the ovarian capsule. The hemorrhage was then irradiated from a distance of 2cm using a series of 1-sec. irradiations at either 30W or 50W until complete hemostasis occurred. In the 30W group, hemostasis was achieved after a total irradiation of 4.1 +/- 1.6 sec. while a significantly shorter time of 2.5 +/- 0.8 sec. was required in the 50W group (p less than 0.01). The irradiation energy in the 30W and 50W groups was 107 +/- 45 J and 109 +/- 35 J, respectively. Tissue temperature was measured during laser irradiation at 5mm and 10mm from the center of irradiation at a tissue depth of 5mm. In the 30W group, the tissue temperature at the 5mm and 10mm points increased 6.6 +/- 2.0 and 2.5 +/- 1.1 degrees C, respectively, while the temperature in the 50W group increased 8.5 +/- 3.5 and 3.1 +/- 0.9 degrees C respectively. No remarkable histological changes were noted in either group following irradiation. YAG laser irradiation during endoscopy is therefore considered to be a highly effective hemostasis for minor hemorrhages caused by instrument manipulation during endoscopic surgery.

Endoscopy↗
PubMed2002

Spatially selective laser coagulation of the gastric wall: a new methodology.

BACKGROUND: The incidence of lymph node metastasis is low in early gastric cancer. Early cancer without nodal metastasis may be theoretically eradicated by local treatment alone. However, except for gastrectomy, there exists no reliable treatment for submucosal cancer. We present a new laser system which irradiates the gastric wall from the serosal side combined with synchronous serosal cooling that can produce deep thermal coagulation without transmural damage. METHODS: A laser handpiece with a built-in surface cooling system has been devised, employing a diode laser of 980 nm wavelength. Animal experiments were conducted to ascertain whether this laser system could coagulate the mucosa and submucosa with acceptable injury to the muscular layer and serosa. The gastric wall was irradiated from the serosal side with synchronous serosal cooling at 6.0-10.0 W power output and 50-400 s exposure time. The degree and depth of damage were histologically assessed after 7 days. RESULTS: Ninety-one points were irradiated in 8 dogs. Mucosal coagulation was observed during the treatment while the serosa showed no serious injury. No gastric perforation occurred up to 7 days later. Histologically, the damage did not penetrate the gastric wall except for cases where 10.0 W and 400 s were used. Cauterization of the mucosa and submucosa with acceptable muscle layer damage was achieved in selected settings. CONCLUSIONS: This laser system enables thermal coagulation of the gastric mucosa and submucosa with acceptable muscle layer damage. This makes it a promising, novel, minimally invasive treatment for submucosal cancer.

Animals↗