Biomedical subjects

L W Rodgers

Publications and source records attributed to L W Rodgers.

4 recordsLinked to original sources

PubMed1995

Depth of penetration of the neodymium: yttrium-aluminum-garnet laser in the human prostate and clinical results of high-dose laser energy in 50 patients.

We evaluated the treatment of the human prostate with the Nd:YAG laser using a Cytocare Prolase II fiber. We utilized this first in 12 patients prior to radical prostatectomy and then appropriately serially sectioned the prostate to measure the depth of penetration. The studies clearly revealed that 60 W of power and 60 s of pulse duration gave the most consistent depth of penetration in the human prostate model. This depth of penetration averaged 2 cm in the glands that were removed. At the same time there was absolutely no evidence of damage to the neurovascular bundle or to the capsule of the prostate using the above-mentioned dosimetry regime. This study was then transferred to our initial experience in treating 50 patients with benign prostatic hypertrophy and obstructive voiding symptoms. The first 25 patients were also treated with so-called spot radiation of the prostate, whereas the second 25 patients were treated by total photoirradiation of all visible endoscopic tissue. The results reveal that both groups of patients had a fairly highly satisfactory result as measured objectively with American Urological Association (AUA) symptom scores and uroflow studies. In the latter group (photoirradiation of all visible endoscopic tissue) a significantly higher dose of laser energy was utilized and a smaller failure rate was noted on a long-term basis in patients who subsequently came to transurethral resection of the prostate (TURP) because of failure of the laser procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Depth of penetration of the neodymium:yttrium-aluminum-garnet laser in the human prostate at various dosimetry.

OBJECTIVE: To determine depth of thermal penetration by the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser at various dosimetry in the human prostate and to compare results of two techniques of laser application, single spot versus whole tissue photoirradiation. METHODS: Twelve men with Stage T2 (B) cancer of the prostate consented to laser prostatectomy immediately prior to a planned radical prostatectomy. In the first 3 patients (group I) the prostate was treated with the Nd:YAG laser in one spot area of each lobe. The next 9 patients underwent photoirradiation of all endoscopically visible tissues on one side of the prostate at different dosimetries: 60 W at sixty seconds (group II), 50 W at sixty seconds (group III), and 40 W at ninety seconds (group IV). Depth of laser penetration was measured from both histologic and gross evaluations of removed specimens within twenty-four hours. RESULTS: Thermal necrosis in group I showed an inconsistent depth of penetration even with the same amount of laser energy. Groups II, III, and IV all demonstrated clearly demarcated areas of thermal necrosis. Group II showed the greatest depth of laser effect among all groups, with a mean depth of 1.75 cm. No laser effect is detected near the true capsule of the prostate on any specimen. CONCLUSIONS: High dosage laser energy application at 60 W and sixty seconds of pulse duration with the whole tissue treatment provide the greatest depth of penetration in the human prostate while maintaining safety for the capsular area.

Burns↗

PubMed1986

Facial bone augmentation using Bioglass in dogs.

In the quest for a material other than autograft and homograft bone for use in facial augmentation and replacement, materials scientists have developed numerous inert materials, some of which have a porous structure allowing scar tissue ingrowth to aid in stabilization of the implant. This study investigates a bioactive, nonporous, transparent glass (Bioglass) in a dog model for use in facial bone augmentation. In 18 dogs studied in three groups at 1, 3, and 6 months, Bioglass implants developed a bond to bone or soft tissue in 54 of 72 instances (75% of the time). Poor bonding of mobile chin implants and the loss of three implants due to infection accounted for all but three of the 18 failures. Histologic evaluation revealed no untoward tissue response. Because of the tissue bonding ability and amenability to contouring with a diamond bur at the time of surgery, Bioglass is promising as a graft material for facial bone augmentation.

Alveolar Ridge Augmentation↗

PubMedDate not supplied

Management of squamous cell carcinoma of the floor of mouth.

Between 1964 and 1987, 194 patients with previously untreated squamous cell carcinoma of the floor of mouth were managed at the University of Florida. A retrospective analysis was undertaken in order to evaluate the treatment results and associated complication rates. Surgery or irradiation alone was found to result in similar local control rates for stage I and II lesions, whereas more advanced tumors had better local control rates with a combination of surgery and irradiation. Radiotherapy had a higher incidence of minor and moderate complications, whereas a greater number of severe complications occurred after surgery. We recommend surgery for early lesions due to the lower overall incidence of associated complications. Despite a higher risk of severe complications, combination therapy is recommended for more advanced lesions due to improved local control as compared to single modality therapy.

Carcinoma, Squamous Cell↗