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Biomedical subjects

R T Cotton

Publications and source records attributed to R T Cotton.

At least 19 recordsLinked to original sources
PubMed1999

Model for evaluating the effect of growth factors on the larynx.

Growth factors are proteins that help regulate the inflammatory response and wound healing in tissues. After laryngotracheal surgery, proper wound healing is important in maintaining the reconstructed airway. The application of growth factor to the respiratory mucosa of the larynx and its effect on wound healing within the airway have not been studied. This study was designed to establish a model for the evaluation of wound healing after the application of growth factor to composite respiratory mucosa and cartilage surfaces at the time of laryngotracheoplasty. Forty rabbits underwent anterior cricoid cartilage split with or without the use of a cartilage graft. Platelet-derived growth factor or a placebo substance was applied to the wound at the time of surgery. This study offers a model for studying wound healing in the airway that is reproducible with limited morbidity.

Animals↗
PubMed1998

S-phase fraction as a predictor of prognosis in juvenile respiratory papillomatosis.

OBJECTIVE: To determine whether DNA ploidy and the S-phase fraction are predictive of the clinical course in children with recurrent respiratory papillomatosis. DESIGN: Masked compression of DNA analysis findings to the clinical course of the disease. SETTING: Tertiary referral center. PATIENTS: All pediatric patients treated for recurrent respiratory papillomatosis at our institution between 1989 and 1995 who had adequate follow-up and whose primary biopsy specimen was available for examination. Fifty-five patients met these criteria. METHODS: Information was collected from the case notes on the patient's age at presentation, sex, sites of disease, duration of active disease, and frequency of operative interventions. Flow cytometric analysis was performed on the archival paraffin-embedded primary biopsy specimen obtained at the initial surgical excision, providing DNA content and percentages of S-phase cells. The investigators who performed the DNA analysis were masked to the clinical course. RESULTS: The age of the patients at presentation ranged from 3 months to 16 years. Thirty patients had involvement in more than 1 anatomical site. The disease in 10 patients had spread to the distal tracheobronchial tree. The patients underwent a total of 1124 procedures, with a frequency range of 7 to 27 per year. All cell populations studied were diploid. The percentage of S-phase cells was significantly higher in the primary biopsy specimen from patients with disease characterized by more frequent recurrences, multiple sites, and distal extension (P<.05). In multiple regression analysis, the S-phase fraction was found to be an independent and powerful prognostic factor for aggressive disease. CONCLUSIONS: The S-phase fraction may be predictive of the clinical course in patients with juvenile respiratory papillomatosis. Prospective studies are needed to assess the diagnostic and clinical value of our primary results and to determine whether DNA analysis can assist in identifying patients at increased risk for an aggressive clinical course.

Adolescent↗
PubMed1998

Gastroesophageal reflux in patients with subglottic stenosis.

OBJECTIVES: To determine the incidence of gastroesophageal reflux in patients with subglottic stenosis (SGS) and to determine if upper esophageal reflux occurs in addition to lower esophageal reflux in these patients. DESIGN: Esophageal pH probe studies were reviewed in patients diagnosed as having SGS. SETTING: A tertiary care pediatric medical center. PATIENTS: All patients diagnosed as having SGS between January 1990 and July 1996 who had undergone monitoring with an overnight esophageal pH probe. Seventy-four patients qualified for the study. All 74 patients underwent lower probe testing, and 55 of the 74 underwent dual (upper and lower) probe testing. MAIN OUTCOME MEASURES: The percent of time a pH measurement of less than 4.0 was recorded in the upper and lower esophagus. A lower probe pH measurement of less than 4.0 more than 10% of the study time was considered high risk for developing reflux-associated pathologic symptoms. A lower probe pH measurement of less than 4.0 for 5% to 10% of the study time was considered a marginal risk for developing reflux-associated pathologic symptoms. Upper probe criteria for reflux-associated symptoms have not been established. Therefore, patients were grouped as having a pH of less than 4.0 in the upper esophagus for 0%, 0.1% to 0.9%, 1.0% to 1.9%, 2.0% to 3.0%, or more than 3% of the study time. RESULTS: Thirty-seven of the 74 patients who underwent lower probe testing had a pH of less than 4.0 more than 5% of the study time, and 24 had a pH of less than 4.0 more than 10% of the study time. Twelve of the 55 patients who underwent upper probe testing had no measurable reflux; 27 of the 55 had a pH of less than 4.0 more than 1% of the study time; 14 had a pH of less than 4.0 more than 2% of the study time, and 11 had a pH of less than 4.0 more than 3% of the study time. CONCLUSIONS: Gastroesophageal reflux is frequently present in patients with SGS. Gastric contents frequently reach the upper and lower esophagus in these patients. In addition, the high incidence of gastroesophageal reflux in these patients suggests that it may play a role in the development of SGS. The possible effect of gastroesophageal reflux on the surgical repair of SGS requires further study.

Adolescent↗
PubMed1998

Significance of DNA ploidy and cell proliferation in juvenile respiratory papillomatosis.

The clinical course of recurrent respiratory papillomatosis (RRP) in children is variable and unpredictable. At present there is no way to identify patients at risk for aggressive disease. The objective of this study was to evaluate whether DNA ploidy and cell proliferation analyses can predict the clinical course in children with RRP. Two different methods of estimating proliferation activity were compared. Nonembedded papilloma biopsy specimens from 18 pediatric patients were analyzed by flow cytometry providing DNA content with cell cycle analysis. The expression of the proliferative marker Ki-67 in papilloma tissue was quantified by immunohistochemistry. The patients were prospectively observed for 12 to 18 months. DNA content analysis and Ki-67 expression were compared to clinical information regarding number of disease sites, distal tracheobronchial spread, number of recurrences, need for tracheostomy, and disease remission. High S-phase fraction, proliferative index, and Ki-67 expression correlated with an aggressive clinical course. DNA ploidy analysis and immunodetection of proliferative markers may assist in predicting prognosis in children with RRP.

Adolescent↗
PubMed1998

Use of Montgomery T-tube in laryngotracheal reconstruction in children: is it safe?

Montgomery T-tubes are often used in adult patients; however, they are less commonly used in the pediatric age group. The purpose of this report is to describe our experience with this stent in pediatric laryngotracheal reconstruction. A retrospective chart review was performed to identify early and late complications. Nutritional assessments were made on the basis of weight percentile comparisons at the time of surgery and at the end of the stenting period. From 1990 to 1997, the Montgomery T-tube was utilized in 26 children undergoing 36 airway reconstruction procedures (21 laryngotracheoplasties and 15 cricotracheal resections). The upper limb of the tube extended above the level of the glottis in all patients. The patients ranged in age from 2.4 to 17.9 years. The duration of stenting ranged from 2 weeks to 23 months. Three patients (11.5%) had significant aspiration and did not improve following diet modifications and swallowing therapy, requiring tube feedings. One patient had postoperative subcutaneous emphysema that resolved spontaneously. Three patients required early removal of the stent due to an inability to tolerate plugging. Granulation tissue above the upper limb of the stent during the stenting period was noted after 6 laryngotracheal reconstruction procedures (16%). Only 1 patient fell off his growth curves during the period of stenting. There were no deaths in this series, and no emergent procedures were required. Postoperative and home care and management of complications are discussed. Our experience indicates that Montgomery T-tubes can be utilized relatively safely in children, providing that postoperative and home care are meticulous.

Adolescent↗
PubMed1998

Airway management in Pierre Robin sequence.

There is a great deal of controversy regarding the long-term management of airway obstruction in children with Pierre Robin sequence. All 23 pediatric otolaryngology fellowship programs were surveyed to determine their current practice patterns. Issues that were addressed included methods of evaluation of airway obstruction, including polysomnography, choices for home care in children in whom observation and positioning treatment failed, and complications of the various treatment modalities. The lack of unanimity among the respondents mirrors the controversy found in the literature. Though tracheotomy appears to be favored as the method of long-term management, responses from those surveyed often were based on emotions as much as on scientific data. This report details those findings and offers suggestions to clinicians involved with the management of patients with Pierre Robin sequence with airway compromise.

Airway Obstruction↗
PubMed1997

Vascular compression of the airway: indications for and results of surgical management.

Vascular compression of the airway is a significant cause of respiratory compromise in children. While the indications for surgical repair are sometimes life threatening, they can also be subtle. This retrospective study examines 45 surgical cases of tracheobronchial compromise secondary to vascular compression at a large children's hospital between July 1983 and February 1996. A total of 34 were diagnosed with innominate artery compression, ten with a double aortic arch and one with an anomalous right subclavian artery. The 45 patients, 25 male and 20 female, ranged in age from 12 days to 11 years at surgery (average 13 months). A total of 21 (47%) presented with proven or suspected episodes of cyanosis or apnea. All 45 patients had evidence of vascular compression during microlaryngoscopy and bronchoscopy. The diagnosis was confirmed by magnetic resonance imaging (MRI) in 23/45 (51%), barium swallow in 22/45 (49%) and aortogram in 3/45 (7%). There was one death. One patient had a tracheotomy before surgery and continues to require it after surgery. Complete resolution of symptoms was achieved in 39/45 (87%) with five requiring more than one operation before their symptoms resolved completely. A total of four patients experienced a recurrence of symptoms within a variable length of time after surgery. Surgical indications and treatment alternatives will be discussed.

Aorta, Thoracic↗
PubMed1997

Autoimmune hypothesis of acquired subglottic stenosis: lack of support at time of surgical repair in children.

Numerous mechanisms have been suggested for the development of subglottic stenosis. This study sought serum antibody and cricoid cartilage immunohistologic evidence of an autoimmune process. The autoimmune hypothesis is that subglottic inflammation may extend into the cricoid cartilage, degrade the extracellular matrix and expose normally-sequestered type II collagen to the afferent arm of the immune system. The resultant anti-collagen antibodies are hypothesized to contribute to further injury and scarring. Specimens were obtained from 10 patients. Immunofluorescent stains for antibodies in histologic specimens, and serum antibodies to type II and type IX collagen were sought. No evidence for an autoimmune process was found in these specimens with the techniques used. The negative findings may be attributable to the autoimmune process being inactive at the mature stage of the disease in the patients studied.

Adolescent↗
PubMed1997

Partial cricotracheal resection with primary anastomosis in the pediatric age group.

The traditional approach to severe subglottic stenosis (SGS) in the pediatric age group is laryngotracheal reconstruction (LTR). This approach may be complex and multistaged, with variable and unpredictable success rates in the individual patient. Excellent results have been reported in adults who had severe SGS and underwent partial resection of the cricoid and primary thyrotracheal anastomosis. This procedure has not been widely reported in infants and children. We report our experience with this procedure in 16 pediatric patients with grade III or IV SGS. Eleven patients had multiple previous LTR operations. The preoperative evaluation, surgical techniques, postoperative care, complications, and final results are described and discussed. Fourteen patients were decannulated after the procedure, 1 patient needed a second open procedure prior to decannulation, and 1 patient with concomitant bronchopulmonary dysplasia remains cannulated, for an overall 94% decannulation rate. Fourteen patients have no limitation of respiration, and 1 patient has moderate exercise intolerance. The results of this series suggest that partial cricotracheal resection with primary anastomosis is a relatively safe and effective procedure for pediatric patients with severe SGS.

Adolescent↗
PubMed1996

Chronic aspiration in children. When are bilateral submandibular gland excision and parotid duct ligation indicated?

OBJECTIVE: To assess the efficacy of bilateral submandibular gland excision and bilateral parotid duct ligation in treatment of chronic aspiration in neurologically impaired children. DESIGN: Retrospective chart review and telephone follow-up interview. SETTING: Tertiary care center. PATIENTS: All patients from 1986 through 1994 who underwent bilateral submandibular gland excision and bilateral parotid duct ligation and had evidence of at least 1 episode of aspiration pneumonia in the year prior to undergoing surgery. MAIN OUTCOME MEASURE: Two main outcomes measures were (1) the change in number of hospitalizations for pneumonia and total number of lower respiratory tract infections between 1 year before and 1 year after surgical intervention and (2) telephone assessment of patient outcome with respect to parental satisfaction, effect on quality of life, care requirements, amount of suctioning, and use of voice. RESULTS: Sixteen patients aged 16 months to 18 years were included. After surgical intervention, there was a significant decrease in the mean (+/-SD) number of pneumonias (2.3 +/- 1.44 before surgery, 0.9 +/- 1.2 after surgery; P < .001) and hospitalizations (1.2 +/- 0.8 before surgery, 0.4 +/- 0.8 after surgery; P < .005). Six patients had a tracheostomy at the time of surgery, and 1 required a tracheostomy 2 years after surgery. No individual required laryngotracheal separation. Eleven families were able to be contacted by telephone. Caretakers reported that in 8 of 11 patients, quality of life was improved and care requirements decreased. Seven patients used voice for at least some degree of communication. Three patients had postoperative complications involving the parotid glands; all resolved after further therapy. CONCLUSION: Bilateral submandibular gland excision and bilateral parotid duct ligation reduce the incidence of aspiration pneumonias and hospitalization, and decrease overall care requirements in a select group of neurologically impaired children. Because they are voice sparing, are efficacious, and have a low morbidity, they should be considered before laryngotracheal separation or tracheoesophageal diversion.

Adolescent↗
PubMed1995

The spectrum of vertigo in children.

OBJECTIVE: To review the presentation, evaluation, and causes of vertigo in children. DESIGN: A retrospective review of children who presented with the chief complaint of vertigo. PATIENTS: Thirty-four children with a chief complaint of vertigo were seen in an ear, nose, and throat clinic during a 2 1/2-year period. OUTCOME MEASURES: Presenting symptoms, diagnostic tests, diagnoses established, and clinical course were evaluated. RESULTS: Otitis media, benign paroxysmal vertigo of childhood, and migraine accounted for the vertigo in 50% of the children. Audiometry, tympanometry, and electronystagmography were the most helpful diagnostic tests, with abnormal results in seven, seven, and six patients, respectively. Of the 19 patients with adequate follow-up, 15 (79%) were improved or asymptomatic at the time of their last visit. CONCLUSIONS: Peripheral causes of vertigo, eg, otitis media, were noted most commonly. Evaluation of vertigo should include a complete history and physical examination, an audiogram, and a tympanogram. In select cases, electronystagmography, electroencephalography, and scanning of the brain or temporal bone should be performed. A favorable outcome was noted in most cases.

Adolescent↗
PubMed1995

Postoperative medical management in single-stage laryngotracheoplasty.

OBJECTIVE: To determine whether it is safe and effective to avoid the use of neuromuscular relaxants in patients who have indwelling nasotracheal tubes after undergoing single-stage laryngotracheoplasty. DESIGN: Retrospective case series. SETTING: University-based referral center specializing in the surgical management of laryngotracheal stenosis and other pathologic conditions of the airway. PATIENTS: Referred sample of 104 consecutive patients (67 males, 37 females) undergoing single-stage laryngotracheoplasty for subglottic stenosis. INTERVENTION: Single-stage laryngotracheoplasty. MAIN OUTCOME MEASURES: Incidence of accidental extubation, use of neuromuscular relaxants, incidence of reintubation after planned extubation, duration of intubation, overall rate of successful airway expansion. RESULTS: One patient self-extubated without sequelae. One patient required a brief course of neuromuscular relaxants. The success rate (without further laryngotracheoplasty) for all patients was 86% (89/104). For the 25 patients operated on in 1992, with at least 1 year of follow-up, the success rate was 92% (23/25). CONCLUSION: Single-stage laryngotracheoplasty can be done safely and effectively without using paralyzing agents in the postoperative period. This approach has certain advantages, which are discussed.

Accidents↗
PubMed1995

Pediatric laryngotracheal reconstruction with cartilage grafts and endotracheal tube stenting: the single-stage approach.

Laryngotracheal reconstruction (LTR) comprises five stages: 1, characterization of the stenosis; 2, expansion of the lumen; 3, stabilization of the enlarged lumen framework; 4, healing of the surgical site; and 5, decannulation. Single-stage LTR (SS-LTR) combines and compresses stages 3 through 5 (stabilization, healing, and decannulation) into a brief period of postoperative intubation. At Children's Hospital Medical Center in Cincinnati, Ohio, from January 1987 to December 1993, 116 reconstructive procedures were performed by using postoperative intubation. Nine were tracheoplasty or stoma-revision procedures in isolation, leaving 107 SS-LTR procedures that included the laryngotracheal complex. The use of SS-LTR has increased to 30% of LTRs performed in 1993. Data are presented on the success of SS-LTR as measured by the number of decannulations and extubations achieved.

Cartilage↗