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Biomedical subjects

R L Crumley

Publications and source records attributed to R L Crumley.

At least 37 records · Page 2Linked to original sources
PubMed1991

Muscle transfer for laryngeal paralysis. Restoration of inspiratory vocal cord abduction by phrenic-omohyoid transfer.

Omohyoid muscle transfer to the denervated posterior cricoarytenoid muscle (PCA) was performed in three monkeys. The transposed omohyoid muscle was reinnervated by the phrenic nerve by performing nerve anastomosis prior to muscle transfer. The muscles were sutured over the denervated ipsilateral PCA muscle to allow for neurotization of the denervated PCA muscle in such a way as to reproduce the directional vector of PCA contraction, eg, to mimic the directional pull of the PCA muscle. The muscle flaps were found to be long enough to reach the contralateral PCA muscle, confirming that the technique might be used ultimately for bilateral simultaneous PCA reinnervation. Each animal achieved reinnervation. The superiorly based omohyoid muscle flap was found to more closely emulate the size and orientation of the underlying PCA muscle. Electromyography, videolaryngoscopy, and histologic examination were used to confirm the results. The procedure has the potential for PCA muscle replacement in long-standing cases of paralysis with PCA denervation atrophy as well as for reinnervating a denervated PCA muscle.

Animals↗
PubMed1991

Effects of pharmacologic agents on human keloids implanted in athymic mice. A pilot study.

The treatment of keloids remains difficult. In experimental studies, lathyrogenic agents and colchicine have been shown to be effective in keloid prevention. Recently, a study was published of a new animal model utilizing human keloids implanted in athymic mice. We used the same model to compare the effects of penicillamine, acetylcysteine, colchicine, and triamcinolone acetonide. Unexpectedly, all keloids implanted showed a growth peak at 4 weeks and then regression in size. Histologic sections of the implanted keloids revealed peripheral vascularity, collagen bundles similar to the parent keloids, and no evidence of implant rejection. After 8 weeks, the mice treated with the lathyrogenic agents exhibited a higher rate of regression when compared with the control mice. While triamcinolone acetonide may have prevented keloid implant growth, drug toxic reaction may have been a factor.

Acetylcysteine↗
PubMed1991

Update: ansa cervicalis to recurrent laryngeal nerve anastomosis for unilateral laryngeal paralysis.

Twenty cases of unilateral laryngeal paralysis are reported. Satisfactory follow-up intervals and data (videostroboscopy and glottographic analysis) were available on 12 patients. The excellent to normal phonatory quality achieved in many of these patients indicates that the ansa cervicalis to recurrent laryngeal nerve anastomosis is the procedure of choice in selected patients with unilateral vocal cord paralysis. Excellent medialization of the paralyzed cord, as well as correction of arytenoid malposition and thyroarytenoid muscle atrophy appear to explain the technique's success, since the reinnervated cord neither abducts nor adducts. We feel that this technique is the procedure of choice in younger patients, or those who use their voices professionally, since the phonatory quality achieved is superior to Teflon injection or Isshiki thyroplasty, and the technique is reversible.

Humans↗
PubMed1991

Does intralaryngeal motor nerve sprouting occur following unilateral recurrent laryngeal nerve paralysis?

Reinnervation of paralyzed intralaryngeal muscles by axonal sprouting from adjacent intact muscles (the phenomenon of muscular neurotization) has been observed, but the source is uncertain. The potential for laryngeal reinnervation of the posterior cricoarytenoid muscle (PCA) from contralateral PCA motor nerve sprouting in a rabbit model was investigated. Unilateral PCA denervation was produced by vagotomy. The rabbits were examined for signs of PCA recovery for up to 6 months, using fiberoptic endoscopy, electromyography (EMG), and histology. No return of vocal cord abduction, EMG activity, or any nerve sprouting across the midline from the intact PCA was found. We conclude that there is no significant spontaneous intralaryngeal muscular neurotization to the paralyzed PCA. The clinical ramifications of our data will be discussed.

Animals↗
PubMed1990

Teflon versus thyroplasty versus nerve transfer: a comparison.

Surgical rehabilitation of the paralyzed larynx is currently performed by Teflon injection, thyroplasty, and reinnervation techniques. Proponents of the two newer techniques maintain that they are preferred to Teflon injection because superior phonatory quality is achievable. This paper was written in an attempt to dissect the issues regarding this question. Teflon remains the quickest and least expensive procedure, but further experience with stroboscopic and other voice analyses reveals that the other procedures demonstrate some superiority in phonatory quality over Teflon. In this author's hands, the nerve transfer offers the best opportunity to achieve a normal phonatory voice. In addition, it is the only one of the three procedures that leaves the vocal cord entirely undisturbed--important in the event one of the other two procedures becomes necessary.

Humans↗
PubMed1990

Repair of the recurrent laryngeal nerve.

Surgical repair and reconstruction of the injured recurrent laryngeal nerve are discussed. Tips to avoid inadvertent nerve injury are noted, as are aspects of non-recurring recurrent laryngeal nerves. The controversy regarding recurrent laryngeal nerve anastomosis is updated, and a protocol for management of the injured recurrent laryngeal nerve is presented.

Anastomosis, Surgical↗
PubMed1989

Surgical access for clivus chordoma. The University of California, San Francisco, experience.

Surgical approaches to clivus chordoma are discussed. The approaches described in this article have been used in an attempt to minimize morbidity while maximizing exposure. The transseptal-transsphenoidal approach is appropriate for biopsy or for subtotal removal of small midline lesions of the upper (retrosellar) clivus only. The radical pterygomaxillotomy approach is used for gaining access to chordomas of the upper half of the clivus, with or without lateral extension. Removal of the lateral, posterior, and (if necessary) medial walls of the maxillary sinus is followed by resection of most of the contents of the pterygopalatine fossa. The pterygoid plates are then removed with a drill. The sphenoid sinus and upper clivus are then exposed for tumor removal. For more inferior lesions, we have modified the transoral-transpharyngeal approach by creating an inferiorly based posterior pharyngeal flap, which increases exposure of the clivus, particularly laterally. This flap can be extended laterally for paraclival extension. This approach allows removal of the lateral clivus as far laterally as the hypoglossal canal, with no dissection of tongue, mandible, lip, or cervical soft tissues.

Chordoma↗
PubMed1989

Laryngeal synkinesis: its significance to the laryngologist.

Basic research and surgical cases have shown that the injured recurrent laryngeal nerve (RLN) may regenerate axons to the larynx that inappropriately innervate both vocal cord adductors and abductors. Innervation of vocal cord adductor muscles by those axons that depolarize during inspiration is particularly devastating to laryngeal function, since it produces medial vocal cord movement during inspiration. Many patients thought to have clinical bilateral vocal cord paralysis can be found to have synkinesis on at least one side. This will make the glottic airway smaller, particularly during inspiration, than would true paralysis of all the intrinsic laryngeal muscles. Patients with bilateral vocal cord paralysis should undergo laryngeal electromyography. If inspiratory innervation of the adductor muscles is present, simple reinnervation of the posterior cricoarytenoid muscle will fail. The adductor muscles also must be denervated by transection of the adductor division of the regenerated RLN.

Adolescent↗
PubMed1989

Cancer of the forehead and temple regions.

Several characteristics inherent in tumors of the forehead and temple provide therapeutic challenges for the physician. These include spread along anatomic structures, a propensity toward aggressive growth patterns, the risk of nerve damage, and the preservation of important cosmetic landmarks. As a result of these problems, Mohs micrographic surgery is often indicated in the treatment of skin cancer of the forehead and temple. The high cure rates afforded by micrographic surgery, even for aggressive tumors, and tissue conservation are benefits to the patient. Although most BCCs and SCCs in this region can be handled by a dermatologic surgeon, patients may present with aggressive or neglected tumors exhibiting extensive invasion. These patients may require a cooperative approach between the dermatologic and head and neck surgeon to achieve complete tumor extirpation or appropriate reconstruction. In this article, we have tried to indicate the rationale behind the use of Mohs micrographic surgery for tumors of the forehead and temple. In selected tumors, a team approach between the micrographic and other surgeons will maximize both tumor excision and functional and cosmetic repair for the patient.

Aged↗
PubMed1988

Quantitative analysis of nasal tip projection.

Previously described methods for quantifying nasal tip projection were evaluated. Fifty-one nasal profiles were analyzed and scored by expert rhinoplastic surgeons. The noses and faces were then evaluated quantitatively using several methods. The methods were found to vary widely in their correlation with the experts' subjective analyses. Several helpful relationships and guides were obtained: 1. Aesthetic tip projection does not correlate well with upper lip length. 2. A new method described in this paper showed the best correlation with the experts' opinions (regression, r value = 0.8132). This method related tip projection to total nasal length (including upper lip length). 3. The second new method tested in this report yielded helpful data by comparing tip projection with overall facial length. 4. After slight modification the method previously described by Goode proved useful as nasal length and desired tip projection formed a 3:4:5 right triangle.

Humans↗
PubMed1988

Nerve transfer versus Teflon injection for vocal cord paralysis: a comparison.

Teflon injection for unilateral vocal cord paralysis frequently produces an improved yet breathy voice. Ansa hypoglossi-recurrent laryngeal nerve anastomosis has been performed in five patients. In the four patients discussed in this paper, excellent phonatory quality has been achieved. Electroacoustic analysis indicates that this technique may produce normal phonatory function in paralyzed larynges. There have been no serious side effects or complications in our first five patients. Denervation of the sternothyroid muscle, which results from sectioning its nerve in preparation for suture to the RLN, appears to further improve the voice by medially positioning the vocal cord. Gelfoam paste is injected at the time of nerve transfer to rehabilitate the voice during the 2 months required for nerve regeneration. For younger patients, or those with professional use of their voices, this technique offers superior speech results when compared with Teflon injection.

Adult↗
PubMed1987

Brachytherapy of recurrent tumors of the skull base and spine with iodine-125 sources.

Thirteen patients with recurrent, previously irradiated tumors of the skull base or spine were reirradiated with 125I sources implanted interstitially using microsurgical or stereotactic techniques. Patients harbored difficult, end-stage recurrences of chordoma, meningioma, malignant meningioma, fibrosarcoma, invasive pituitary adenoma, and malignant schwannoma. In two other patients with malignant meningioma, the dose of external radiation was augmented by implanting 125I sources during the initial operation for excision of the lesion or at a separate surgical procedure after conventional teletherapy. Microsurgical implantation of 125I sources into basal tumors was limited by the difficulties inherent in operating in this region; it is not possible to visualize the entire tumor that requires implantation. Three of five chordomas stabilized or regressed; these patients probably benefited from the procedure. Two patients with recurrent malignant meningiomas had long term remission after interstitial brachytherapy. Interstitial 125I brachytherapy for recurrent tumors at the base of skull or adjacent to the spine can be more successful only if more aggressive surgical exposures of these regions are attempted. Implantation of sources for a "boost" dose, either microsurgically during the initial surgical resection of the lesion before conventional teletherapy or stereotactically after conventional teletherapy, may be a valuable adjunct to external irradiation for the control of potentially devastating tumors (such as chordomas and malignant meningiomas) before they recur with the severe consequences seen in the patients reported here.

Adenoma↗
PubMed1987

Cine CT in obstructive sleep apnea.

The upper airway was evaluated in eight patients with obstructive sleep apnea by using a rapid sequential CT scanner (Imatron C-100). Four patients also had simultaneous polysomnograms to determine the onset of sleep and apnea. The upper airway was scanned while the patient was awake (eight patients), asleep (four patients), and asleep and apneic (eight patients). Measurements of the cross-sectional area of the upper airway were correlated with the findings on sleep studies in four patients. During the awake state the airway was narrowed and showed increased collapsibility in all eight patients. Five of the eight patients had cross-sectional areas of less than or equal to 4 mm2 at one or more sites at some time during the respiratory cycle while awake. During apnea all patients had obstruction at the uvula and oropharynx, but the length of the obstruction varied from one patient to another. In three of the eight patients the obstruction extended inferiorly to the hypopharynx. Cine CT can be used to objectively evaluate patients with sleep apnea and may demonstrate the need to modify surgical treatment.

Adult↗
PubMed1987

Determination of obstructive site in obstructive sleep apnea.

Patients with obstructive sleep apnea syndrome (OSAS) may have airway obstruction at various levels, including the uvula-soft palate complex, base of tongue, and/or possibly other sites. For patients with tongue base and/or laryngeal obstruction, uvulopalatopharyngoplasty (UPPP, ppp) will not alleviate the obstruction. Prior authors have proposed that the hyoid bone position as determined by cephalometric x-rays can predict which patients have obstruction at a lower site than the soft palate. In this study, patients with obstructive sleep apnea syndrome were evaluated with polysomnographic testing, fiberoptic endoscopy, and cine-CT scans (Imatron Scanner with multiple level rapid sequence scans) in an attempt to determine precisely the site of airway obstruction. Measurements of airway size taken at the time of fiberoptic pharyngoscopy were compared with those determined by the cine-CT studies. Initial results revealed that fiberoptic pharyngoscopy in the sitting and supine positions was helpful in confirming pharyngeal airway sites with smaller diameters in awake patients. However, the cine-CT exam performed in both sleeping and awake states provided more direct data regarding the airway during sleep. We feel that with more clinical experience the cine-CT technique will prove to be the most helpful study for identification of the obstructive airway site in obstructive sleep apnea syndrome.

Airway Obstruction↗
PubMed1986

Voice quality following laryngeal reinnervation by ansa hypoglossi transfer.

Recurrent laryngeal nerve injury resulting in chronic unilateral vocal fold paralysis has been treated traditionally by implantation of various materials into the paralyzed vocal fold. Although the usage of these techniques, especially Teflon-glycerin paste injection, has been clinically established, they do not restore full functionality to the larynx (abduction, adduction, and vibratory synchronization of the vocal folds). Restoration of these functions, necessary for improved phonation, has been achieved at least on an experimental basis by reinnervation techniques previously described. This study demonstrates excellent human voice quality following reinnervation of the vocal folds in two cases using ansa hypoglossi-recurrent laryngeal nerve anastomosis. Although the reinnervated vocal fold neither abducted nor adducted, it presented itself in the midline for precise apposition with the nonparalyzed cord. Voice data were analyzed within a single subject experimental design at the following intervals; preoperatively, immediately postoperatively, midterm, and long-term (3 and 6 years). The data was analyzed by subjective and objective means, including acoustics and electroglottography. Patient selection, surgical techniques, results, and implications are reviewed.

Adult↗