Injectable synthetic extracellular matrices for tissue engineering and repair.
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Animals↗
Biomedical subjects
Marshall E Smith
Publications and source records attributed to Marshall E Smith.
Cross-linked hyaluronan-coated stents in the prevention of airway stenosis.
OBJECTIVE: This project studies the use of airway stents coated with a cross-linked derivative of hyaluronan (HA) in a rabbit airway model of subglottic stenosis (SGS). STUDY DESIGN AND SETTING: An acute subglottic mucosal injury and airway stent placement design were used in a rabbit model. Thirty-six rabbits were randomized to 6 different study groups. Four groups had the subglottic mucosa denuded at the cricoid, and 2 groups received no injury. Airway stents coated with Carbylan-SX, a cross-linked derivative of HA, and controls were placed for 3 weeks. After sacrifice at 6 weeks, morphometric measurements of subglottic lumen were taken. RESULTS: In posttraumatic models, no significant differences were seen in airway area measures between groups (P = 0.86). In non-injury groups, a significant difference between Carbylan-SX versus non-HA-derivative-coated stents was seen (P = 0.05). CONCLUSION: In this model of acute subglottic mucosal injury, the HA-derivative-coated stent did not improve healing. However, in the absence of mucosal injury, the Carbylan-SX film-coated stent yielded significantly larger airway areas compared with a noncoated stent. SIGNIFICANCE: Stents or endotracheal tubes coated with a cross-linked derivative of HA may prevent stenosis in patients without airway injury but require long-term intubation or laryngotracheal stenting.
Acute Disease↗
Lidocaine block of the recurrent laryngeal nerve in adductor spasmodic dysphonia: a multidimensional assessment.
OBJECTIVES/HYPOTHESIS: Lidocaine block of the recurrent laryngeal nerve (RLN) has been reported as a procedure for surgical selection of patients with adductor spasmodic dysphonia (ADSD). However, its effects on phonation have not been rigorously assessed in a prospective fashion using strict entry criteria and multiple measures of phonatory function. This investigation assessed the phonatory effects of RLN lidocaine block in ADSD to explore its potential as a diagnostic tool. STUDY DESIGN: Single group, pre/postexperimental trial. METHODS: Twenty-one consecutive patients with suspected ADSD underwent unilateral RLN block, causing temporary ipsilateral vocal fold paralysis. Voices were recorded before and during the block. Patients completed self-ratings of overall level of dysphonia severity, vocal effort, and laryngeal tightness. Blinded listeners completed auditory-perceptual ratings, and the frequency of phonatory breaks was acoustically analyzed. RESULTS: During the block, patients reported significant reductions on overall severity (P = .045), vocal effort (P < .001), and laryngeal tightness (P = .002). Listeners rated the voices during the block as significantly more breathy (P < .001), less strained (P < .001), and less severe (P = .059). Acoustic analysis confirmed significantly fewer phonatory breaks during the block (P < .001). Patient-based ratings of improvement were more consistent than listener ratings, and reduction in overall severity correlated with perceived breathiness. CONCLUSIONS: Although individuals varied in their outcomes, group results suggest that response to RLN lidocaine block warrants further study as a possible diagnostic tool in ADSD.
Anesthetics, Local↗
Patterns of laryngeal electromyography and the activity of the respiratory system during spontaneous laughter.
Laryngeal muscle electromyography (EMG) and measures of the behavior of the respiratory system have been made during spontaneous laughter in two groups of subjects. The smaller group also had a direct measure of tracheal pressure during this behavior. Laryngeal adductors such as the thyroarytenoid (TA) and lateral cricoarytenoid (LCA) exhibited brief high-amplitude bursts of activity, at a rate of approximately 5 Hz, which were usually associated on a 1 : 1 basis with the sound bursts (ha ha ha) of laughter. The laryngeal abductor, posterior cricoarytenoid (PCA), also showed bursts of activity that were out of phase with TA and LCA. The cricothyroid (CT) was only weakly, if at all, modulated during the bursting activity of the other laryngeal muscles. Tracheal pressure usually exhibited positive pressure pulses during laughter that were often, but not always, temporally correlated to the bursts of laryngeal adductor EMG activity. Such pressure modulations appeared to precisely determine when-and if-phonation was produced during the laugh. During laughter, laryngeal EMG is highly stereotyped both within and between subjects. In most instances, this activity appears to be supported by coordinated pulses of tracheal pressure. The periaqueductal gray (PAG) has been shown in animal studies to produce emotionally indicative vocalizations, in which the laryngeal and respiratory system are coordinated. Therefore, it is suggested that the PAG is involved with the production of laughter.
Action Potentials↗
Differential gene expression profiling of vocal fold polyps and Reinke's edema by complementary DNA microarray.
OBJECTIVES: Our purpose was to determine whether complementary DNA (cDNA) microarray analysis (MA) can establish distinct gene expression profiles for 2 phenotypically similar vocal fold lesions: Reinke's edema (RE) and polyps. Established transcript profiles can provide insight into the molecular and cellular processes involved in these diseases. METHODS: Eleven RE specimens and 17 polyps were analyzed with MA for 8,745 genes. Further MA profiling was attempted within each lesion group to identify molecular markers for reflux exposure and smoking. Prediction analysis was used to predict lesion classification for 2 unclassified samples. A real-time polymerase chain reaction was performed to corroborate MA transcript levels for selected significant genes. RESULTS: Sixty-five genes were found to differentiate RE and polyps (p = .0088). For RE, 19 genes were differentiated for reflux exposure (p = .016). No genes were found to differentiate smokers from nonsmokers. For polyps, no genes were found to differentiate for reflux (p = .16) and smoking (p = .565). Categorization of unclassified lesions was possible with a minimum of 13 genes. CONCLUSIONS: We demonstrate the feasibility of benign lesion classification based on MA. Microarray analysis is useful not only for improving diagnosis and classification of such lesions, but also for potentially generating prognostic indicators and targets for therapy.
Adult↗
Pediatric invasive fungal rhinosinusitis in immunocompromised children with cancer.
OBJECTIVES: 1) To determine the factors that predispose towards invasive fungal rhinosinusitis (FS) in immunocompromised children with cancer, and 2) to propose practice guidelines for management of pediatric FS in immunocompromised patients. METHODS: Retrospective chart review of 9 patients who developed invasive FS compared to 8 patients who did not develop invasive FS during the study period. Presenting signs and symptoms, nasal endoscopic findings, radiographs, laboratory studies, histologic and microscopic samples, and outcomes were compared. RESULTS: Seventeen consecutive pediatric immunocompromised patients with hematologic and lymphoid neoplasms underwent nasal endoscopy and biopsy for possible FS. Nine patients were diagnosed with 10 episodes of FS; 1 patient developed FS with different organisms on 2 separate occasions separated by 6 months; 8 patients were not diagnosed with FS. Eight patients had acute myelogenous leukemia (AML); 6 patients had acute lymphoblastic leukemia (ALL); 1 patient had Burkitt's lymphoma, 1 patient had undifferentiated leukemia; and 1 patient had biphenotypic acute leukemia. All patients with FS had an absolute neutrophil count (ANC) 600 or less (range 0-600). All patients with FS had either persistent fevers or sinus symptoms (facial pain, nasal congestion, rhinorrhea). Sinus CT scans were abnormal in all patients with FS and without FS. Two patients with FS had maxillary sinus retention cysts. Operative endoscopic findings were helpful diagnostically when necrosis or ulceration was found. All patients in the non-FS group normalized their ANCs; 2 of the 9 patients in the FS group did not normalize their ANC. These 2 patients died from disseminated FS or from complications due to their immunosuppression. CONCLUSION/SIGNIFICANCE: All patients with FS had either persistent fevers or symptoms localized to the sinuses (facial pain, nasal congestion, or rhinorrhea). Endoscopic examination was helpful when necrosis was detected. We recommend directed biopsies of suspicious lesions, the middle and inferior turbinate, in immunocompromised, neutropenic pediatric patients with cancer who present with either persistent fevers or localizing symptoms to the sinuses. We favor the use of "rush" biopsies over frozen sections because of the better-quality sections and ability to perform appropriate stains.
Adolescent↗
Task specificity in adductor spasmodic dysphonia versus muscle tension dysphonia.
OBJECTIVES: Adductor spasmodic dysphonia (ADSD) has been characterized as a "task specific" laryngeal dystonia, meaning that the severity of dysphonia varies depending on the demands of the vocal task. Voice produced in connected speech as compared with sustained vowels is said to provoke more frequent and severe laryngeal spasms. This study examined the diagnostic value of "task specificity" as a marker of ADSD and its potential to differentiate ADSD from muscle tension dysphonia (MTD), a functional voice disorder that can often masquerade as ADSD. STUDY DESIGN: Case-control study. METHODS: Five listeners, blinded to the purpose of the study, used a 10 cm visual analogue scale to rate dysphonia severity of subjects with ADSD (n = 36) and MTD (n = 45) producing either connected speech or a sustained vowel "ah." RESULTS: In ADSD, dysphonia severity for connected speech (M = 6.22 cm, SD = 2.56) was rated significantly more severe than sustained vowel productions (M = 4.8 cm, SD = 2.8 [t (35) = 3.67, P < .001]). In MTD, however, no significant difference in severity was observed for the connected speech sample (M = 5.98 cm, SD = 2.83 versus the sustained vowel M = 5.86 cm, SD = 2.87 [t (44) = 0.378, P = .707]). The receiver operating characteristic (ROC) curve, an index of the accuracy of task specificity as a diagnostic marker, revealed that a 1 cm difference criterion correctly identified 53% of ADSD cases (sensitivity) and 76% of MTD cases (specificity) (chi2 (1) = 6.88, P = .0087). CONCLUSIONS: Reduced dysphonia severity during sustained vowels supports task specificity in ADSD but not MTD and highlights a valuable diagnostic marker whose recognition should contribute to improved diagnostic precision.
Adult↗
Endoscopic vertical partial laryngectomy.
OBJECTIVE: To explain the significant difference between microlaryngoscopy with cordectomy and endoscopic vertical partial laryngectomy (EVPL), to describe the efficacy of EVPL on T1b and T2 glottic squamous cell carcinoma, and to evaluate EVPL with postoperative irradiation in T2 glottic cancer with impaired true vocal cord mobility. STUDY DESIGN: Retrospective review. METHODS: Twenty-six patients seen at the University of Utah Health Science Center between 1987 and 2000 with bilateral T1 (T1b) or T2 squamous cell carcinoma of the glottic larynx underwent EVPL. T2 cancers were classified as follows: a = unilateral disease, b = bilateral disease; i = impaired mobility. T1b and T2a glottic cancer patients received surgery alone, whereas impaired mobility patients (T2ai + T2bi) patients received surgery followed by planned postoperative irradiation. Patients were assessed for primary site control, perioperative and long-term complications, and ultimate cancer control. RESULTS Survival in the total group was 88.5%, with local control at 92.3%. The two recurrent patients were salvaged by total laryngectomy. For the whole group, anterior commissure involvement was present in 57.7% (15 of 26). Thirteen T2 (5 T2ai + 8 T2bi) carcinoma patients underwent combined therapy, with 8 (61.5%) of these patients having anterior commissure involvement. Two of these patients were upstaged at surgery, one to T3 and one to T4. Local control was 84.5%. Thirteen patients were treated by surgery only, with five of these patients having failed previous irradiation. Survival was 92.3% and local control 100%. This group included two T2bi patients, two patients upstaged to T4 on the basis of extension beyond the subglottis to the anterior wall of the trachea, 3 T2b, and 6 T2a patients. Anterior commissure involvement was seen in 7 (53.8%) of these patients. CONCLUSIONS: EVPL alone controlled all T1b and T2a glottic cancer patients, even in the presence of greater than 50% anterior commissure involvement. The significant difference between EVPL and classical microlaryngoscopy with cordectomy was carefully described. EVPL with planned postoperative irradiation resulted in an 85% local control rate in clinically staged T2ai and T2bi cancer patients, including the three upstaged patients.
Adult↗
Cosmetic considerations in surgery for orbital subperiosteal abscess in children: experience with a combined transcaruncular and transnasal endoscopic approach.
OBJECTIVE: To evaluate the outcomes of a new surgical approach in children with acute sinusitis and medial orbital subperiosteal abscess. DESIGN: Case series. SETTING: Tertiary pediatric hospital. PATIENTS: Eleven children aged 6 weeks to 13 years with orbital subperiosteal abscess and acute sinusitis who met indication for surgery by visual compromise and/or refractory course to medical therapy. INTERVENTION: The medial orbital abscess was drained via a transcaruncular approach, which provided access to the medial orbital wall. An endoscopic ethmoidectomy was also performed. MAIN OUTCOME MEASURES: Judgment of cosmetic appearance by surgeon and family, resolution of symptoms, length of hospital stay, and complications. RESULTS: All children had prompt resolution of symptoms after surgical drainage. Cosmetic outcome was excellent in all patients with no cutaneous scar or eyelid malposition. After edema and cellulitis had resolved, no family member could tell a difference in appearance between the eyes. No complications of these combined procedures were identified. One patient who had initially undergone transnasal endoscopic orbital drainage alone experienced a recurrence of infection 17 days later. He was then treated by the combined transcaruncular and endoscopic approach with prompt resolution of his symptoms. One of 4 patients treated initially with transcaruncular approach alone without endoscopic ethmoidectomy had recurrence of acute sinusitis and orbital abscess 16 months later and was successfully treated with an endoscopic approach. CONCLUSIONS: The combined endoscopic and transcaruncular surgical approach to medial orbital subperiosteal abscess and acute sinusitis provides a cosmetically superior outcome compared with standard orbital approaches requiring a cutaneous incision. The transcaruncular approach can be considered as an alternative or adjunct approach to the medial orbit, with the same cosmetic advantages as transnasal endoscopic drainage.
Abscess↗
Voice, speech, and swallowing outcomes in laser-treated laryngeal cancer.
OBJECTIVE: To describe preliminary voice, speech, and swallowing outcomes in patients treated by endoscopic laser excision of laryngeal cancer with or without adjuvant radiation therapy. STUDY DESIGN: Retrospective review. METHODS: Seventeen surgically treated patients (five T2 glottic and 12 clinically staged T2 supraglottic squamous cell carcinomas) participated in the study. Self-ratings of voice (Voice Handicap Index) and swallowing (M. D. Anderson Dysphagia Inventory) were completed, as well as independent auditory-perceptual ratings of voice and speech recordings. RESULTS: Although no significant difference between Voice Handicap Index, M. D. Anderson Dysphagia Inventory, and listener ratings was identified based on tumor site and irradiation status, there was a trend toward poorer outcomes in patients who received adjuvant radiation therapy. Whereas the patients having supraglottic cancer tended to report better voice but poorer swallowing outcomes, the glottic cancer group displayed the opposite pattern. Severity on Voice Handicap Index correlated significantly with listener severity ratings of speech, suggesting that the patients' perception of their voice handicap was similar to the listeners' judgments of their speech severity. CONCLUSIONS: The results suggest the following trends: 1) Adjuvant radiation therapy was associated with poorer outcomes for voice, speech, and swallowing and may be associated with more impairment than surgery alone and 2) poorer outcomes on voice and swallowing were observed for the glottic and supraglottic cancer groups, respectively. To bolster these preliminary findings, additional outcomes studies in patients treated with conservation therapy are needed.
Adult↗
Genotypic and phenotypic expression of vocal fold polyps and Reinke's edema: a preliminary study.
Although a great deal of research exists regarding lamina propria composition, no report exists that relates gene expression in benign laryngeal lesions to phenotypic markers. In this study, messenger RNA profiles for extracellular matrix proteins--procollagen I, collagenase, elastase, fibronectin, fibromodulin, decorin, hyaluronic acid synthase 2, and hyaluronidase--were completed on 5 polyps and 4 Reinke's edema specimens. These genotypic profiles were correlated to a videostroboscopic parameter of mucosal wave stiffness, which was used as a measurement of phenotypic expression. Polyps, characterized by stiffer mucosal waves, had higher levels of gene expression, whereas stiffer mucosal wave scores for Reinke's edema were associated with lower gene activity levels. This study supports the hypothesis that there is a relationship between genotypic expression found in polyps and Reinke's edema and phenotype as defined by a loss of or a decreased mucosal wave. The study also gives clues as to the proteins responsible for the phenotype.
Base Sequence↗