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Biomedical subjects

M Waner

Publications and source records attributed to M Waner.

At least 37 records · Page 2Linked to original sources
PubMed1995

Management of congenital vascular lesions of the head and neck.

Congenital vascular lesions are often misdiagnosed and, for the most part, left untreated. The absence of a uniformly accepted classification of these lesions and confusion over their natural history are partly responsible. A new classification of these lesions recognizes two distinct groups of lesions, hemangiomas and vascular malformations. Hemangiomas are usually not present at birth, proliferate during the first year of life, and then involute. In contrast, vascular malformations are always present at birth, never proliferate, and never involute. Knowledge of this classification system will facilitate the diagnosis of these lesions and lead to appropriate, individualized treatment.

Head and Neck Neoplasms↗
PubMed1994

Beam profile of the flashlamp pumped pulsed dye laser: support for overlap of exposure spots.

The degree to which individual practitioners overlap exposure spots of the flashlamp pumped pulsed dye laser when treating large vascular lesions appears to be a matter of personal preference. There are few data to support one approach over another. We have measured the beam profile of this laser at two different energy fluences using a photodiode and a digitizing storage oscilloscope. Results show that for each energy fluence, the beam intensity decreases from the center to the outside rim of the beam. A plot of beam intensity versus the radius of the treatment field approaches a truncated normal distribution with a full width at half-maximum of 4.7-4.8 mm. These results help explain why clinical overlap of exposure spots can be safely undertaken and provide a rationale for recommendations concerning the degree of overlap needed to expedite treatment while still minimizing adverse reactions.

Hamartoma↗
PubMed1994

[A laser therapy concept in telangiectasis and naevus flammeus].

The superficial lesions of the telangiectasia and the ectatic vessels in port-wine stains are a suitable aim for photocoagulation using yellow light lasers. Yellow light of the wavelength 575-585 nm provides good absorption by oxyhaemoglobin and only minimal damage to the overlying skin. After the use of continuous wave dye lasers, therapeutic progress has been achieved with pulsed lasers such as the copper vapour and flashlamp pumped dye lasers (FLPD). Advantages of the copper vapour laser are in the treatment of telangiectatic lesions that can be traced easily with the spot size of 100 microns, as well as in severe port-wine stains in adults (cobble-stone formation). The FLPD laser is feasible in the treatment of port-wine stains in children. Examples are shown of telangiectasia and port-wine stains of different grades and the resulting consequence for yellow light laser treatment.

Adolescent↗
PubMed1994

Laser photocoagulation of superficial proliferating hemangiomas.

Hemangiomas present at, or soon after birth, proliferate and eventually involute. In spite of this, children may suffer severe psychosocial trauma during the formative years of their lives, and, in a proportion of cases, a cosmetically unacceptable result is left at the end of involution. Since flashlamp pumped dye lasers have been shown to selectively destroy ectatic dermal vascular tissue through intact epidermis, 6 patients with very early superficial cutaneous hemangiomas were treated. All treated areas resolved completely and treatment was completed by 12 months. No complications were encountered apart from mild, temporary post-inflammatory hyperpigmentation which was seen in one patient. This, however, resolved completely within 3 months of treatment. Flashlamp pumped dye lasers are thus able to effect complete resolution of very superficial proliferating cutaneous hemangiomas in neonates and infants without the risk of scarring.

Arm↗
PubMed1993

Tumor specific response to photodynamic therapy.

The exact mechanism by which photodynamic therapy (PDT) causes tumor destruction has not been elucidated. Early reports indicated that PDT causes direct cellular effects probably mediated by unstable oxygen species, resulting in cellular oxidation and death. More recently, PDT effects on tumor blood flow have been implicated, and there are questions as to whether the PDT response is specific to tumor tissue. Rats were implanted with a window chamber containing either a mammary adenocarcinoma or a piece of inert surgical sponge. After growth of the tumor was ascertained, all rats were given 5 mg/kg Photofrin intraperitoneally, and then were irradiated with 630 nm light 24 hours post-injection. Caliper thickness and reflectance measurements were performed before and after irradiation; all animals were sacrificed 72 hours post-PDT and the chambers submitted for histologic analysis. Animals implanted with tumors demonstrated marked edema of the chamber with an associated decrease in reflectance. No edema response was noted in the chambers containing inert sponge, or in any controls. Nonselective PDT effects (characterized by a marked foreign body response) in chambers containing sponge was not seen. Histologic analysis of treated specimens corroborate the above data.

Animals↗
PubMed1993

The copper vapor laser for treatment of cutaneous vascular and pigmented lesions.

BACKGROUND: Clinical experience has shown that a variety of skin lesions are treatable with rapidly pulsed yellow and green light of the copper vapor laser. OBJECTIVE: To review the development, use, complications, and efficacy of the copper vapor laser when utilized for cutaneous lesions. METHODS: Articles were identified through a MEDLINE search, review of these articles' bibliographies, and advice from expert physicians who have used the copper vapor laser. RESULTS: A variety of vascular and pigmented cutaneous lesions are effectively treated with the copper vapor laser. A distinct advantage for hypertrophic or cobblestoned port-wine stains and most types of facial telangiectasia is seen when this laser's results are compared with the results of other available laser systems. Complications, including scarring, are rarely observed. CONCLUSION: The copper vapor laser is a useful addition to the family of lasers that are used for cutaneous conditions.

Facial Neoplasms↗
PubMed1993

A comparison of copper vapor and flashlamp pumped dye lasers in the treatment of facial telangiectasia.

METHODS: Twelve adult patients with bilateral facial telangiectasias were treated with two yellow light lasers. A section of each involved area was treated with a copper vapor laser and a similar section in the same patient was treated with the flashlamp pumped dye laser. RESULTS: Both lasers provided satisfactory clearance at 2 and 6 weeks. Treatment was not painless with either laser; however, no patient needed local or general anesthesia. The time taken to treat equivalent areas was similar for both lasers. Postoperative swelling was greater with the flashlamp pumped dye laser than with the copper vapor laser and the time required for healing was longer with the flash-lamp pumped dye laser. CONCLUSION: The larger purpuric macules produced post-operatively by the flashlamp pumped dye laser were less cosmetically acceptable to patients when compared with the thin linear crusting produced by the copper vapor laser. Scarring or textural changes were not seen with either laser.

Adult↗
PubMed1993

Immunoperoxidase study of the endolymphatic sac in Menière's disease.

A growing body of evidence suggests that some cases of Menière's disease may be mediated by immune mechanisms. Because endolymphatic sac dysfunction is believed to be an underlying cause of Menière's disease, this study used immunohistochemical techniques to demonstrate the presence of immune complex deposition in the sacs of patients with Menière's disease. Positive immunoglobulin G (IgG) staining was noted in 10 of 23 sac biopsies from Menière's patients, with 2 specimens showing perivascular deposition. Only 1 of 5 control specimens was only slightly positive for IgG. Clinical correlation showed a statistically significant increase in disease bilaterality (P < .05), larger summating potential/action potential (SP/AP) ratios with electrocochleography (ECoG), and a tendency toward worse hearing and more progressive disease among the immunopositive Menière's patients. The results provided histological evidence of immune injury in the endolymphatic sacs of patients with Menière's disease.

Action Potentials↗
PubMed1993

[Yellow light laser photocoagulation of vascular malformations in the head and neck area].

Laser surgery techniques have become well established in otolaryngology. Yellow light lasers emit light in the visible spectrum. Laser light in the spectrum of 380-700 nm shows different effects after absorption at a specific chromophore. For the treatment of vascular lesions of the skin controlled absorption of energy by blood is necessary to avoid uncontrolled damage and vaporization. Chromophores of the skin which absorb energy transmitted by laser light are hemoglobin, bilirubin, oxyhemoglobin, beta carotene, collagen and melanin. The penetration of the laser light depends on its wavelength. In vascular lesions oxyhemoglobin is the chromophore whereas melanin is the chromophore in pigmented malformations. The argon-pumped dye laser, copper vapor and flash-lamp pumped dye laser emit laser light of 577, 578 and 585 nm. These lasers are especially useful for photocoagulation of oxyhemoglobin and for selective destruction of vascular tissue. The risk of hypotrophic or hypertrophic scarring is minimal (< 1%) because there is less alteration of the overlying dermis. The aim of the present study was to test, in a clinical setting, the copper vapor laser in vascular lesions of the head and neck.

Adolescent↗
PubMed1992

Selective destruction of facial telangiectasia using a copper vapor laser.

Copper vapor lasers emit pulsed light at 511 and 578 nm. The 578-nm option corresponds with a peak in the absorption of oxyhemoglobin and a diminished absorption by melanin. The pulse width of this light (20 nanoseconds) is significantly shorter than the thermal relaxation time of typical facial telangiectatic vessels (20 to 100 milliseconds). This laser is therefore able to selectively destroy facial telangiectatic vessels with little damage to the overlying epidermis. Twenty patients with facial telangiectasia were treated with the 578-nm option of a copper vapor laser. Treatment was administered in an office-room setting, and no anesthesia was used. Eighteen of the 20 patients experienced satisfactory clearance of their telangiectasia. Three patients developed temporary postinflammatory hyperpigmentation, which cleared within 6 to 8 weeks, and one patient developed a small depressed scar, which was not noticeable at 3 months. Copper vapor lasers are thus safe and effective in treating facial telangiectasia.

Adult↗
PubMed1992

Treatment of hemangiomas of the head and neck.

Hemangiomas are a group of pediatric tumors that present at or soon after birth. Rapid proliferation is seen in the neonatal period, and may continue for the first year of life. Involution follows, and may last as long as 12 years. Since hemangiomas invariably involute, the vast majority have been left untreated. At least 10% to 20% of cases, however, will need active intervention, traditionally in the form of oral Prednisone. The frequent occurrence of life-threatening complications, permanent deformities, and irreversible psychosocial damage in spite of adequate steroid therapy necessitated a fresh look at the management of these lesions. Using recently developed laser technology alone or in combination with surgical excision, the authors have developed guidelines for safe intervention in all stages of the hemangioma cycle. Safe, active intervention in accordance with these guidelines offers an alternative to the more conservative approach previously advocated.

Child↗
PubMed1990

Laser photodynamic therapy for papilloma viral lesions.

Photodynamic therapy was tested for its therapeutic efficacy in eradicating rabbit papilloma warts. The wild-type viral warts suspension was used to induce treatable papilloma warts in the cutaneous tissue of Dutch Belted rabbits. The photosensitizing agents used intravenously were Photofrin II at 10 mg/kg of body weight and Chlorin e6 monoethylene diamine monohydrochloric acid (Chlorin e6 med HCl) at 1 mg/kg of body weight. The lasers used were an argon-dye laser at 628 and 655 nm and a gold vapor laser at 628 nm. The irradiances of 25 to 180 mW/cm2 were applied topically with an end-on lens optical fiber with total radiant doses of 7.5 to 54 J/cm2. Photofrin II and the argon-dye laser at the highest light dosage (54 J/cm2) and Chlorin e6 monoethylene diamine monohydrochloride administered 2 hours before argon-dye laser irradiation at 655 nm at the highest light dosage (54 J/cm2) produced wart regression. Total wart regression without recurrence was achieved with Photofrin II and the gold vapor laser at all light dosages. The difference observed between the argon-dye laser and the gold vapor laser might be explained by the pulsed nature of the gold vapor laser, with its high-peak powers, some 5000 x the average measured light dose. In this model, the smaller, less cornified lesions were more effectively treated with photodynamic therapy.

Animals↗
PubMed1989

Treatment of oral cavity vascular malformations using the neodymium:YAG laser.

Although rare, hemangiomas and lymphangiomas of the oral cavity are difficult management problems. Surgical resection is still commonly thought of by many when considering treatment. Several articles in 1986 reported good results using the neodymium:yttrium-aluminum-garnet laser for these lesions. Using this laser, we have treated six patients with hemangiomas or lymphangiomas of the oral cavity over the past 4 years. Although most patients have required several treatments, the response has been excellent overall. This report confirms the results of previous studies.

Adolescent↗