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Biomedical subjects

R K Davis

Publications and source records attributed to R K Davis.

At least 55 records · Page 3Linked to original sources
PubMed1985

The masticator space: the influence of CT scanning on therapy.

The masticator space is an important suprahyoid tissue compartment bounded by the superficial layer of the deep cervical fascia, enclosing the ramus of the mandible plus the masseteric and pterygoid muscles. Pathology of this space has been clinically difficult to diagnose and treat. Twenty-five patients with either tumor or infection involving the masticator space who underwent CT scanning were evaluated retrospectively. Ten patients had infection and 15 had tumor. CT was influential in directing appropriate biopsies or therapy in 24 of 25 patients. It misguided therapy once. The gross anatomic and CT appearance of the normal and the diseased masticator space is described along with pictures of representative cases. A discussion is given of the advantages, disadvantages, and pitfalls of computerized tomography of the masticator space.

Abscess↗
PubMed1985

Prognostic variables in head and neck cancer. Tumor site, stage, nodal status, differentiation, and immune status.

Currently the best prognostic indicator of cancer response is that of staging by the American Joint Commission Staging System. This system is most helpful in state I and in stage IV patients as a prognosticator. Caution must be exercised in oral cavity stage I cancers which tend to be more threatening and where further staging techniques should be used. The major need for careful prognostic indicators beyond simple staging is clearly evident in the stage II and stage III group. In this group, the histologic criteria of Jakobsson, the nuclear criteria suggested by Holm, and the immunologic staging parameters discussed here will hopefully better predict survival, and more importantly, guide therapy. Finally, the role of induction chemotherapy as a prognostic indicator itself has great potential and is currently being heavily investigated.

DNA, Neoplasm↗
PubMed1984

The deltopectoral flap v the pectoralis major myocutaneous flap. Which one?

During the past 2 1/2 years, we have used 21 deltopectoral (DP) and 25 pectoralis major myocutaneous (PM) flaps of which 25 were applied to oral and pharyngeal defects. The concurrent use of both flaps has enabled elucidation of some specific and relative advantages and disadvantages. The following five situations have been identified in which we believe the PM flap is clearly superior: (1) lateral mandibular composite resection defects; (2) large anterior segmental defects; (3) reconstitution of tongue and base of tongue; (4) radionecrosis; and (5) through-and-through defects of skin and oral cavity. The DP flap appears to hold an advantage in the repair of the following defects: (1) limited anterior mandibular loss; (2) posterior and lateral pharyngeal loss; (3) complex resections involving the palate; and (4) cervicofacial skin. The unique advantages of each flap must be weighed against certain disadvantages. Application to each reconstructive problem should be individualized. Proficiency with both flaps enhances the surgeon's ability to deal with major ablative procedures.

Humans↗
PubMed1984

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

Seven patients with a total of 12 roots were treated with overdentures (maxillary, mandibular, or both) and recalled at 6-month intervals for a period of 4 years. A periodontist evaluated the periodontal health status of the abutment roots after complete periodontal therapy, immediately prior to placement of the overdentures, and at all recall visits. The gingival tissues around all the abutments were slightly erythematous and edematous and bled on probing. There were no statistically significant changes in pocket depth or in apparent width of attached gingiva on an intra-arch basis. However, statistically significant changes were found on comparison between the maxillary and mandibular arches. Over the 4-year period 50% of the roots remained immobile, 25% of the roots that were initially mobile exhibited no mobility, and 25% of the roots decreased in mobility. Five of 14 roots in eight patients (35.7% of the abutment roots) developed dental caries. Periodic recalls to reinforce plaque control measures, to provide adjunctive periodontal therapy, and to correct and adjust the prostheses of patients treated with overdentures are important factors in the longterm success of this treatment modality. Biomechanically, treatment of patients with overdentures is a valid practical alternative to complete dentures.

Dental Abutments↗
PubMed1984

Cervical epidural anesthesia for head and neck surgery.

Patients with head and neck cancer frequently suffer from chronic obstructive pulmonary disease and arteriosclerotic cardiovascular disease, making them poor risks for anesthesia. Arrhythmogenic inhalation anesthetics along with assisted ventilation used in general anesthesia further complicate the intraoperative, as well as the postoperative, course. Cervical epidural anesthesia has been employed in a number of cases of breast and upper thoracic surgery at Walter Reed Army Medical Center with remarkable success. It has also been used in chronic pain control. We described the use of cervical epidural anesthesia for a neck dissection. The technique of placing 0.5% Marcaine at the level of C7-T1 is described. Indications, limitations, complications, and the potential uses of cervical epidural anesthesia in head and neck cancer patients are discussed.

Anesthesia, Epidural↗
PubMed1983

Transoral partial supraglottic resection using the CO2 laser.

Transoral epiglottis resection or partial supraglottic resection was done with the CO2 laser in 20 highly selected patients. Visualization was best accomplished using the Lynch suspension system, but was satisfactory with the Jako-Pilling laryngoscope. The best indications for this procedure were: 1. for visualization of the true vocal cords in previously treated cancer patients whose epiglottis obstructed indirect mirror examination, 2. for removal of obstructing benign epiglottic lesions, 3. as an excisional biopsy in limited epiglottic cancer, especially of the suprahyoid epiglottis. No major complications or operative morbidity occurred. This approach obviated the potential morbidity of external surgical procedures In a select group of patients. Shortened hospitalization, avoidance of tracheotomy, minimal postoperative discomfort and edema, and excellent wound healing were additional advantages seen.

Adult↗
PubMed1983

A baseline study of periodontal conditions among youths and adults in Portugal.

A study was undertaken in 1979 to obtain baseline data of periodontal disease and treatment needs among rural and urban Portuguese. From Montemor-o-Novo, Alentejo and from Lisbon, 255 persons (121 males, 134 females) aged 15-44 yr were selected by a stratified quota sampling method and examined under field conditions using both Russell's Periodontal Index (P.I.), slightly modified, and components of a proposed new WHO method. The latter formed the basis for estimation of treatment need according to the Community Periodontal Index for Treatment Needs (CPITN). Periodontal disease as assessed by the P.I. exhibited epidemiologic characteristics which in several respects were similar to those reported in other populations. Severity increased with increasing age and there were trends towards more severe disease in males than in females, and more severe disease in rural than in urban districts. Relatively few cases of advanced periodontitis were detected by the P.I. as applied in this study. The underestimation of disease prevalence inherent in the scoring method, the high tooth mortality and the fact that only relatively young individuals were studied may have contributed to this finding. Great need for various types of periodontal therapy were found through CPITN assessments. However, relatively few individuals were in need of "complex periodontal therapy" as assessed by the CPITN.

Adolescent↗
PubMed1983

Palliation of airway obstruction from tracheobronchial malignancy: use of the CO2 laser bronchoscope.

A CO2 laser rigid bronchoscope system has been used to palliate symptoms of a malignancy obstructing the tracheobronchial airway. Fifty-nine endoscopic laser operations (34 patients) were done between 1975 and 1981. Severe dyspnea and obstructive atelectasis were the most common indications for treatment. Contraindications for treatment included extrinsic tracheobronchial compression, widespread distant metastases, rapidly progressing tumors, and highly vascular neoplasms. There were nine primary tracheal malignancies, five metastases from distant sites, and 20 primary lung cancers with tracheobronchial obstructions. Most patients were previously treated with one or more standard modalities (radiation therapy, surgery, and chemotherapy). Removal of airway obstruction was occasionally indicated prior to radiation therapy to facilitate treatment. There were seven instances of complications in this group of patients and one mortality. Most patients (23 of 34) have died from their malignancy. The best palliation was achieved in proximal (tracheal and main stem bronchial), slower growing tumors.

Aged↗
PubMed1983

Induction chemotherapy with vinblastine, bleomycin, and cis-diamminedichloroplatinum in squamous cell carcinoma of the head and neck.

The results of induction chemotherapy with vinblastine, bleomycin, and cis-platinum II are reported. No survival advantage was seen when the entire treatment group was compared with an historical control group. Special attention is directed to the meaning of complete response and the potential treatment options and survival advantages of the complete responders subgroup.

Adolescent↗
PubMed1983

Phase II trial of mitoguazone in patients with advanced squamous cell carcinoma of the head and neck.

We used mitoguazone (500 mg/m2 iv weekly, with 50-mg/m2 escalations weekly as tolerated) to treat 22 patients with squamous cell carcinoma of the head and neck which recurred after initial therapy. Nine of 22 (11%) patients responded: two had complete responses and seven had partial responses. Gastrointestinal toxicity and anemia were commonly seen. We conclude that mitoguazone is active in squamous cell carcinoma of the head and neck and should be incorporated into phase III trials.

Adult↗
PubMed1983

Laser bronchoscopic surgery.

Endoscopic laser bronchoscopy can be used to effectively palliate patients with compromised airways. The CO2 laser was utilized with a ventilating bronchoscope. This form of endoscopic surgery has the advantage of less postoperative edema, better hemostasis, more accurate tumor vaporization, and shortened operating time. Between 1975-79 33 laser bronchoscopies were carried out for airway obstruction. Palliation was achieved in most cases. Complications included intra-operative bleeding, tissue fragment occlusion of the airway, and an endotracheal fire. Laser bronchoscopy should be avoided in the presence of widespread metastatic disease, poorly differentiated or rapidly growing tumors, extrinsic tumor compression, or highly vascular tumors. A preliminary report is presented on the soft tissue effects of the argon laser, passed through a flexible coaxial cable in the canine trachea. Multiple transmural lesions were created. The use of the argon laser in the field of bronchoscopy remains controversial.

Adult↗
PubMed1982

Role of endocrine function tests in the evaluation of transsphenoidal hypophysectomy for advanced breast cancer.

Forty-three women underwent transsphenoidal hypophysectomy for metastatic breast cancer. Endocrine tests (luteinizing hormone, follicle-stimulating hormone, thyrotropin, prolactin and growth hormone) were done in 28 patients to evaluate the completeness of the procedure. Response of the metastatic breast cancer and duration of survival after hypophysectomy were determined and statistically compared with the posthypophysectomy hormone levels. Only one patient had an endocrinologically complete hypophysectomy, but the objective remission rate (32 percent) is comparable to the 30 to 40 percent objective remission rate reported in other studies that claim to have achieved complete hypophysectomy. No statistically significant associations were found between the levels of the hormones measured and the type of response (objective, subjective or none) to hypophysectomy. However, objective responders survived longer than nonresponders (p = 0.01). When analyzing the associations of the various hormone levels with the duration of survival after hypophysectomy, a positive correlation (p less than 0.05) of peak thyrotropin levels with duration of survival was found. Our data indicate that the clinical benefit advanced breast cancer patients received from an endocrinologically incomplete hypophysectomy is probably as great as that received from an endocrinologically complete hypophysectomy. It appears that a nonspecific disturbance of the hormonal milieu may adversely affect the growth of breast cancer. More studies are needed to elucidate the nature of the endocrine disturbance produced by hypophysectomy and its effects on hormone-sensitive tumors.

Adult↗
PubMed1982

The anatomy and complications of "T" versus vertical closure of the hypopharynx after laryngectomy.

The early postoperative hypopharyngeal anatomy of 37 consecutive patients undergoing total laryngectomy at the Boston Veteran's Administration Hospital between July 1977 and April 1980 was studied by barium swallow radiographs and correlated with the technique of closure. The "pseudoepiglottis," a structure radiographically resembling a normal epiglottis, was seen arising from the anterior hypopharynx near the base of the tongue in 21 of 28 evaluable patients. It occurred in all patients with vertical closures vs. 67% of patients with a "T" shaped closure. The average length in the "T" closure group was 9.6 mm (range 0-35) vs. 18.4 mm (6-40) in the vertical group, a statistically significant difference (p less than 0.05). Radiologic strictures occurred in 39% of all patients, dysphagia in 29%, fistulae in 18%, and sinus tracts in 14%. All complications occurred more frequently in the vertical closure group. Patients who received preoperative cis-platinum bleomycin chemotherapy and postoperative irradiation had 50% dysphagia and 67% stricture rates. The average ratio of the width of the retropharyngeal space to that of C4 was 0.48 in stricture patients vs. 0.29 in non-stricture patients (statistically significant at the p less than 0.01 level). This ratio taken in the early postoperative period may help predict which patients will develop strictures.

Bleomycin↗