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Biomedical subjects

R K Davis

Publications and source records attributed to R K Davis.

At least 73 records · Page 4Linked to original sources
PubMed1982

The anatomic limitations of CO2 laser cordectomy.

The anatomical limitations of CO2 laser cordectomy in an experimental setting with maximal exposure are presented. The major limitation is the thyroid cartilage. This is reached in the area of anterior commissure tendon by removal of only 2 to 3 mm of soft tissue. Most posteriorly in the larynx, the distance to the thyroid cartilage becomes progressively greater, being 5.3 mm at mid-cord and 9.0 mm at the anterior end of the vocal process of the arytenoid. The inferior limitation is the cricothyroid membrane. Anteriorly this is avoided by not extending laser excision more inferiorly than 5 mm's. Posterolaterally, the limitation is the para-arytenoid musculature. Excisional biopsy or staging with the laser must be within the framework of these limitations.

Biopsy↗
PubMed1981

A two-year longitudinal study of the periodontal health status of overdenture patients.

Eleven patients who were treated with maxillary or mandibular overdentures or both were recalled at 6-month intervals and studied for a period of 2 years. A periodontist evaluated the periodontal health status of the abutment teeth at initial placement of the overdenture and at all subsequent recalls using standardized periodontal indices. Statistical comparisons of the data from initial examination to the 2-year recall were made to assess the periodontal health status of roots supporting overdentures. Periodic, regular recall of patients treated with overdentures is one of the most important factors in the maintenance of the integrity of the root stumps and attachment apparatus, particularly since the roots supporting mandibular overdentures are at greater risk periodontally than those supporting maxillary overdentures. Measurements of pocket depth and width of attached gingivae seem to be the most definitive criteria to determine the status of the attachment apparatus in overdenture patients. With frequent recall, overdentures appear to be a successful method of treatment.

Denture Design↗
PubMed1980

Clinical and laboratory studies on human sclera allografts.

In the first section of this two-part report human peripheral blood leukocytes were tested for reactivity to extracts of sclera. Absence of scleral antigenicity is suggested by the results which showed that the leukocytes reacted similarly in sclera stimulated cultures and in the controls. The second part of the report discusses the clinical aspects of sclera allografts and provides guidelines for their clinical use. A case is presented where a sclera graft was in position for approximately a year. The tooth was removed with the attached graft and a histologic study made.

Alveolar Process↗
PubMed1980

Peristomal recurrence: pathophysiology, prevention, treatment.

Postlaryngectomy peristomal recurrence is the most devastating late complication of laryngeal carcinoma. Its development is most closely associated with emergency tracheotomy done prior to definitive treatment of the primary tumor and with subglottic tumor involvement. The pathophysiologic mechanism of the development of peristomal recurrence is by tumor seeding of the tracheotomy site, by metastatic spread to the pretracheal and paratracheal nodes (especially from the subglottis), and by direct extension of tumor through the thyroid cartilage, cricoid cartilage, or cricothyroid membrane. The best treatment is the prevention of peristomal recurrence. Intubation followed by partial laser excision of the primary tumor can be used to avoid tracheotomy in some cases. Patients showing subglottic involvement by tumor should undergo either postoperative irradiation of the stoma or prophylactic recurrent laryngeal lymphatic and superior mediastinal dissection by removal of the manubrium sterni and sternoclavicular joints. When peristomal recurrence develops, radiation alone offers the least chance of success. Induction chemotherapy should be considered when the condition of the patient allows this. This must be coupled with full course irradiation or mediastinal dissection in operable patients. Mediastinal dissection should be done only by those experienced with the technique and should be accompanied by appropriate postoperative support.

Aged↗
PubMedDate not supplied

Diagnosis of salivary gland tumors by fine needle aspiration biopsy.

The cytologic findings of 51 smears obtained by fine needle aspiration biopsy from salivary gland masses were compared with the histologic findings of permanent sections. The overall concurrence rate between cytologic and histologic findings for being and malignant lesions was 91%. The diagnostic accuracy (exact histologic diagnosis) for the benign lesions was 87% and for the malignant tumors 60%. One case showed false-positive results and 1 case false-negative results. Fine needle aspiration biopsy has been found to be safe, free of complications, and helpful in the planning of treatment.

Adult↗
PubMedDate not supplied

Incidence of Wharton's duct stenosis in floor of the mouth cancers excised with scalpel or cautery vs CO2 laser.

Surgery of the floor of the mouth (FOM) using a scalpel or cautery has produced stenosis of Wharton's duct, necessitating further surgery because of painful enlargement to the gland or suspected metastasis. The laser has been proposed as an alternative method that might avoid this complication. A retrospective study comparing these excisional techniques was done at Walter Reed Army Medical Center between 1973 and 1983. Of a total of 58 lesions, 35 were T1N0M0 and 23 were T2N0M0 (two synchronous lesions being present). Of 35 lesions excised with a scalpel, 11 had an associated submandibular gland resection. Of the remaining 25, two developed secondary duct stenosis. Of 10 lesions excised with cautery, three had an associated excision of the submandibular gland. Of the remaining seven, two developed stenosis and one required subsequent excision of the gland. Of 12 lesions excised with laser, four developed stenosis and two required subsequent excision of the gland. Laser excision appears to be of no advantage in avoiding further surgery of the submandibular gland. A submandibular gland resection at the time of the original resection of T1N0 or T2N0 cancers of the FOM does not appear warranted.

Constriction, Pathologic↗
PubMedDate not supplied

Endoscopic laser management of supraglottic cancer.

Current concepts of endoscopic management of supraglottic cancer are an extension of precepts fostered by Jackson. The current approach has been facilitated by a half century of technological developments: the surgical microscope, the CO2 laser, improved laryngoscopes, and general endotracheal anesthesia. Selected small-volume cancers can be curatively resected, whereas excisional biopsy can be performed on larger neoplasms. With this cost effective minimally-invasive surgical approach, there is less disturbance of normal tissue, thereby minimizing morbidity rate and hospitalization. If the transoral excision is inadequate, radiotherapy can not be depended on to eradicate known residual disease. Endoscopic resection of supraglottic cancer should not alter the surgeon's standard management of the neck.

Endoscopy↗
PubMedDate not supplied

Pretreatment airway management in obstructing carcinoma of the larynx.

Partial endoscopic excision of obstructing laryngeal carcinoma with the CO2 laser is an alternative to emergency tracheotomy or emergency laryngectomy whenever the airway control can be initially ensured by endotracheal intubation. The practical advantages of this approach are elimination of the septic complications of tracheotomy, the opportunity for planned preoperative chemotherapy or radiation therapy, and better nutritional and psychologic preparation of the patient for surgery.

Adult↗
PubMedDate not supplied

Medullary carcinoma of the thyroid masquerading as idiopathic vocal cord paralysis.

The following conclusions may be drawn as a result of our study: 1. Serum calcitonin by radioimmunoassay proved to be the only valid preoperative indicator in a case of medullary carcinoma of the thyroid occurring with vocal cord paralysis. This test should be considered in all cases of idiopathic recurrent laryngeal nerve paralysis, especially when obscure thyroid pathology is suspected. 2. Provocative calcitonin testing, such as a calcium infusion test, may help verify presence or absence of disease in equivocal cases of calcitonin assay. 3. Vocal cord paralysis may be the first sign of intrathroid malignancy. 4. In the furture, serum calcitonin assay (drawn posttreatment) may be a valuable prognostic indicator and may guide the need for additional treatment.

Adult↗