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Biomedical subjects

L M Vistnes

Publications and source records attributed to L M Vistnes.

At least 19 recordsLinked to original sources
PubMed1987

Unilateral invasive xanthelasma palpebrarum.

We describe an unusual case of an aggressively invasive, recurrent xanthelasma palpebrarum which was unilateral in its occurrence. Despite characteristics that appeared malignantly invasive clinically, the lesion was benign. The surgical treatment consisted of wide excision and resurfacing of the eyelids with full-thickness skin grafts.

Eyelid Diseases↗
PubMed1987

Correction of enophthalmos and superior sulcus depression in the anophthalmic orbit: a long-term follow-up.

The purpose of this study was to review the long-term results in anophthalmic patients treated for enophthalmos. The patients in our series had augmentation of the volume of their orbital contents by subperiosteal placement of room-temperature vulcanized silicone. From 1972 to 1985, sixty-three patients received subperiosteal placement of room-temperature vulcanized silicone for their enophthalmos. Twenty-four of these patients were seen in long-term follow-up 1 to 13 years postoperatively. Indepth follow-up evaluation showed that room-temperature vulcanized silicone subperiosteal implantation for the treatment of enophthalmos and superior sulcus depression in the anophthalmic orbit is a reliable, safe procedure that is without serious complications and has excellent long-term results.

Adult↗
PubMed1986

A concentration gradient of bacteria within wound tissues and scab.

This investigation was designed to evaluate the effect of a synthetic moisture vapor permeable dressing on the size of the bacterial population of superficial wounds. Split-thickness donor sites were created in pig skin and were treated with a synthetic occlusive dressing (Tegaderm), with fine mesh gauze, or with nothing. All wounds became spontaneously infected with a variety of bacteria, predominantly with Staphylococcus epidermidis. The population of the Tegaderm wounds was always greater than that of the untreated controls, while that of the gauze treated wounds was equal to or less than that of the controls. Tegaderm dressed wounds healed more quickly than did the others. A gradient in the concentration of bacteria within the wounds was seen, with a very high concentration in the scab (10(8) cells/g), an intermediate concentration (10(6) cells/g) in the dermal layer, and the lowest concentration (10(4) cells/g) in the hypodermal level of the wound tissue. Such a gradient has not previously been reported. No evidence was seen that the level of infection declined over time for any of the dressings. Apparent bacterial clearing in earlier investigations may be due to the progressive loss of superficial wound tissues with the corresponding exclusion of the high concentration of bacteria within these layers from the tissue sampled.

Animals↗
PubMed1986

Surgical reconstruction of a difficult orbital cleft.

The natural history of an untreated coloboma with an orbital cleft in a 14-year-old girl is presented. The method of the surgical reconstruction of this defect is presented in detail: in a single operation the bony cleft was repaired and grafted, the globe was enucleated, and the lids and sockets were reconstituted.

Adolescent↗
PubMed1985

The incidence of experimental contracture varies with the source of the prosthesis.

Nominally equivalent gel-filled miniprostheses supplied by three different manufacturers were placed subcutaneously in rats under identical conditions in a double-blind comparison. The incidence of experimental contracture, defined by grossly visibly asymmetrical distortion of the implant, was 0, 9, and 91 percent for the different manufacturers, consistent with previous observations. Differences among the different implants with respect to the density of the fibrillar capsule structure, the cellularity, and the amount of extruded gel did not correlate with the incidence of contracture. Contracture rate was inversely proportional to the relative degree of filling of the prostheses, as reflected in deviations from the nominal hemispherical shape, and to the viscosity of the gel filling. For implants of the same type, the incidence of contracture was higher when the prosthesis was underfilled. Contracted capsules were more fibrous and contained more cells with microfilament bundles. It is concluded that the physical and geometric properties of silicone implants are critical in the expression of contracture and that these properties vary significantly among prosthesis manufacturers.

Animals↗
PubMed1985

The augmentation of soft tissue with injectable collagen.

Clinical experience has demonstrated the value of injectable collagen in treating small soft-tissue defects. Among the lesions that respond best to injectable collagen therapy are nasolabial and glabellar lines as well as areas of atrophy and soft scars. This material is a useful adjunct to surgical procedures and can correct contour irregularities that may follow rhinoplasty or rhytidectomy. The safety of injectable collagen has also been well demonstrated. The nature and incidence of treatment reactions (less than 3 per cent) remains unchanged since the close of clinical trials. Reactions have been localized, and although some have been cosmetically undesirable, none has been health-threatening. All ultimately resolve without therapeutic intervention. Immunologic studies have confirmed the benign nature and specificity of reactions to injectable collagen. The importance of proper injection technique cannot be overstated. Immediately upon injection, tissue blanching followed by whealing and overcorrection should be evident. These indicate the desired superficial placement of the material. The overcorrection helps to compensate for the loss of carrier saline, and it quickly dissipates. When properly injected, injectable collagen can be used safely and effectively to correct an array of soft-tissue contour irregularities.

Antigens↗
PubMed1984

Capsule contracture in animals can be characterized by gross deformation of prostheses and surrounding tissue.

Gel-filled miniprostheses were implanted in rats, recovered, and reimplanted in fresh animals. Experimental contracture characterized by severe, visually detectable distortion of hemispherical prosthesis mounds into pointed ovoid structures oriented laterally was observed. This finding confirms the existence in rats of a phenomenon similar in appearance to clinical contracture in humans. The incidence of contracture was higher than in the first implantation of these prostheses, which suggests that some property of the prosthesis is critical in the occurrence of contracture, and that this property can be altered by prolonged implantation in the tissue so that contracture is more likely. Implants that were overfilled by injection of extra fluid into the gel showed no contracture, but capsules around these implants did not differ from contracted capsules in protein, collagen, glycosaminoglycan composition, weight, thickness, histological appearance, or incidence of myofibroblasts.

Animals↗
PubMed1984

An in-depth look at pressure sores using monolithic silicon pressure sensors.

Three-dimensional scalar pressure distributions were measured in solid tissue near bony prominences in vitro in meat and in vivo in pigs using silicon pressure sensors. Data are in accord with previous theoretical models and indicate that pressure is three to five times higher internally near a bony prominence than it is at the skin over the prominence. Pressure sores are thus thought to begin internally; by the time they are evident at the skin, the sore has worked its way completely from bone to skin. This conclusion is in accord with previous clinical data. Future measurement of local vector forces is needed to fully characterize the force distribution in vivo.

Animals↗
PubMed1983

Comparison of synthetic adhesive moisture vapor permeable and fine mesh gauze dressings for split-thickness skin graft donor sites.

SAM and fine mesh gauze dressings were compared on 60 consecutive skin graft donor sites. SAM dressings are significantly better than fine mesh gauze dressings for healing of split-thickness skin graft donor sites; healing occurs much more rapidly with much less pain. In patients known to be colonized with Pseudomonas, care should be taken when using SAM dressings, although it is not an absolute contraindication. There were no clinically significant differences between Tegaderm and Op-Site.

Adolescent↗
PubMed1983

Correction of lower eyelid ptosis in the anophthalmic orbit: a long-term follow-up.

We describe a 10-year review of 53 patients having had correction of lower eyelid ptosis using fascia lata sling suspension by the operation first described in 1973. The overall conclusion is that this continues to be a reliable procedure with a low complication rate. Four major changes relating to operative technique that create a better result are as follows: (1) the surgical correction must begin with a prosthesis that is ideal for the socket; (2) the fascial strip is narrower at 2 mm; (3) the lateral orbital rim burr hole is placed higher; and (4) the passage of the fascial strip is facilitated by the use of Wright's needle. The optimal sequence of operative procedures in the anophthalmic orbit syndrome is (1) correction of enophthalmos and superior sulcus depression, (2) correction of lower eyelid ptosis, and (3) correction of upper eyelid ptosis.

Adolescent↗