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Biomedical subjects

R Metson

Publications and source records attributed to R Metson.

At least 19 recordsLinked to original sources

The role of image-guidance systems for head and neck surgery.

BACKGROUND: Although image-guidance systems have gained widespread acceptance for neurosurgical procedures, their role for extracranial surgery of the head and neck is yet to be defined. OBJECTIVES: To describe the authors' experience with image-guidance systems and to measure the effects of image-guided technology on the performance of minimally invasive otolaryngological procedures. DESIGN: Prospective cohort study. METHODS: Optical- and electromagnetic-based image-guidance systems were used during the performance of endoscopic surgery on patients with disease of the paranasal sinuses, orbit, skull base, and temporal bone (n = 79). Results were compared with those in control patients who underwent similar surgery without image guidance during the same period (n = 42). RESULTS: Intraoperative anatomical localization was accurate to within 2 mm at the start of surgery in all cases. Accuracy degraded by 0.89 +/- 0.20 mm (mean +/- SE) during the operative procedure. The use of an image-guidance system increased operating room time by a mean of 17.4 minutes per case (image-guidance group, 137.3 +/- 6.0 minutes [mean +/- SE]; control group, 119.9 +/- 5.7 minutes; P=.006) and increased hospital charges by approximately $496 per case. Intraoperative blood loss (image-guidance group, 178.4 +/- 18.0 mL [mean +/- SE]; control group, 149.4 +/- 20.1 mL) and complication rates (image-guidance group, 2.7%; control group, 4.7%) did not differ significantly between groups. CONCLUSIONS: Image-guidance systems can provide the head and neck surgeon with accurate information regarding anatomical localization in cases with poor surgical landmarks caused by extensive disease or prior surgery; however, the use of such systems is associated with increased operative time and expense.

Adolescent

Clinical outcome of endoscopic surgery for frontal sinusitis.

OBJECTIVE: To determine the efficacy of endoscopic surgery for chronic frontal sinusitis. DESIGN: A prospective analysis of established measures of clinical outcome (Chronic Sinusitis Survey and Short Form 36) that was administered to patients before frontal sinus surgery and at intervals of 3 months, 6 months, and 1 year after surgery. INTERVENTIONS: For limited disease, the frontal recess was opened and the frontal ostium probed or enlarged. For more severe cases, a drill was used to resect the frontal sinus floor and interfrontal septum. SETTING: Private and institutional-based practices at an academic medical center. SUBJECTS: Eighty-seven patients who underwent endoscopic surgery for frontal sinusitis, including 24 patients with severe disease who underwent a frontal sinus drillout procedure. MAIN OUTCOME MEASURES: Scores on the Chronic Sinusitis Survey, Short Form 36, and surgical revision rate. RESULTS: Significant improvement in facial pain, nasal drainage, and congestion was observed 1 year after surgery (P<.01). Medication use was also significantly reduced during this period (P<.01). Quality-of-life measures showed greatest improvement in the domain of social functioning (P<.05). Three (12.5%) of 24 patients who underwent a frontal sinus drillout procedure did not respond to surgery secondary to restenosis of the frontal ostium. CONCLUSIONS: Although the long-term results of endoscopic surgery for frontal sinusitis are unknown, this approach appears to be effective for most patients and may provide a reasonable alternative to frontal sinus obliteration surgery in selected cases.

Adolescent

Economic implications of chronic sinusitis.

An approach to cost analysis useful in understanding the economic implications of surgical intervention on chronic sinusitis is break-even time analysis. The break-even time is the time until cost savings associated with improved health status after surgery equal the up-front costs of the operation itself. Data from 100 consecutive patients undergoing sinus operation were obtained by survey before surgery and at quarterly intervals for 1 year with statistically validated outcome measures (Medical Outcome Study Short Form 36-Item Health Survey, Chronic Sinusitis Survey). Direct and indirect costs were obtained or derived for this cohort. The cost of sinus medications, including over-the-counter remedies, nasal steroid sprays, and antibiotics, averaged $1220 per patient per year before surgery and $629 after surgery (p < 0.0001), which is a 48% reduction. Surgical costs averaged $6490 per patient. Economic modeling predicted a break-even time of approximately 7 years assuming a 3% surgical revision rate per year, a 3% decrease in sickness-related disability, and a 5% discount rate. The model was sensitive to changes in the total cost of operation, the surgical revision rate, and the anticipated disability benefit. We conclude that significant direct and indirect medical cost savings may be achieved after surgical intervention for chronic sinusitis and these savings eventually break even with the total cost of surgery itself.

Absenteeism

A comparison of image guidance systems for sinus surgery.

OBJECTIVE: Intraoperative computed tomographic guidance systems are available which utilize either electromagnetic (radiofrequency) or optical (infrared) signals to localize instruments within the surgical field. The objective of this study was to compare the use of these two different image guidance technologies for sinus surgery. STUDY DESIGN: Prospective cohort study. METHODS: The electromagnetic-based InstaTrak system (n = 24) and the optical-based Stealth-Station (n = 49) were compared in a series of 73 consecutive sinus series which utilized image guidance technology. RESULTS: Both the electromagnetic and optical systems provided anatomic localization to within 2 mm during surgery. Intraoperative reregistration was effective in correcting for any anatomic drift. There were no intraoperative complications. Mean operative times were 156.3 +/- 8.9 minutes for the electromagnetic and 139.2 +/- 17.7 minutes for the optical system (P < .05). The average intraoperative blood loss did not differ significantly between groups (electromagnetic, 190.6 +/- 28.7 mL; optical, 172.4 +/- 23.0 mL). Each system was noted to have limitations. The presence of metallic objects in the operative field interfered with functioning of the electromagnetic system, whereas the optical system required a clear line of sight to be maintained between the infrared camera and surgical handpiece. Both systems required specialized headsets to be worn by patients during surgery to monitor head position. The electromagnetic system also required these headsets to be worn during the preoperative computed tomography scan. CONCLUSION: Although these two image guidance systems both proved valuable for anatomic localization during sinus surgery, individual preferences can be based on distinct differences in their design and operation.

Adult

Effects of sinus surgery on speech.

OBJECTIVE: To determine the effects of sinus surgery on the production and perception of speech. DESIGN: Vocal recordings were performed before, 1 week after, and at least 1 month after sinus surgery. Acoustic spectra were analyzed for nasal consonants /m/ and /n/, nasalized vowels, and nonnasalized vowels. Results for nasal consonants were compared with similar recordings obtained from a group of normal subjects with no history of sinus disease. Perceptual analysis of nasalized vowels was conducted by trained phoneticians. SETTING: Private practice at an academic medical center. SUBJECTS: Five patients who underwent endoscopic sinus surgery and 3 normal subjects. MAIN OUTCOME MEASURES: The spectral characteristics and perceptual attributes of nasal sounds. RESULTS: Significant differences in spectral properties were observed for the consonants and nasalized vowels recorded before and after surgery (P < .001). Perceptual experiments for nasalized vowels demonstrated a postoperative decrease in nasality for the high vowel /i/, as in "beep," and an increase in nasality for the non-high vowel /ae/, as in "bad." These perceived changes correlated well with acoustic measures of nasal peak amplitudes and the lowest resonance peak amplitude of the vocal tract. CONCLUSIONS: Sinus surgery results in measurable effects on the produced acoustic signal and the perceived nasality of a patient's speech. The identified acoustic correlates may be useful for preoperative counseling of patients concerning expected changes in speech quality following surgery.

Adult

Comparison of sinus computed tomography staging systems.

In an attempt to establish a standardized rating system for CT of the paranasal sinuses, the Committee on Rhinology and Paranasal Sinus Disease of the American Academy of Otolaryngology-Head and Neck Surgery instituted a protocol for the review of sinus CT scans at six international sites. Fifty identical scans were rated by four otolaryngologists at each site according to five established sinus CT staging systems. Twenty of 24 reviewers repeated the rating session at least 1 week later to determine intrarater variability. The number of CT scans that could not be classified by a particular rating system ranged from 1.3% to 5.5%. The range of intrarater agreement (kappa = 0.39 to 0.74) exceeded that of interrater agreement (kappa = 0.18 to 0.49). A skewed distribution of CT scans resulted in a system with high rater agreement but poor ability to differentiate among disease states. The use of a numeric rating system to assign a score to each scan produced a comprehensive and disease-sensitive system, but one with low rater agreement. A precise definition of mucosal thickening in terms of millimeters appeared to enhance the raters' ability to assign stage and improve a system's comprehensiveness and reproducibility. On the basis of these findings, recommendations are made for the use of CT rating systems to study clinical outcomes in patients with chronic sinusitis.

Humans

Effect of sinus surgery on quality of life.

Although sinus surgery may reduce the incidence of recurrent infection in patients with chronic sinusitis, little is known about the effect of such surgery on a patient's quality of life. One hundred eight patients undergoing ethmoid sinus surgery were prospectively evaluated with statistically validated measures of sinusitis-specific and general health-related quality of life. Twelve months after surgery significant improvements were found in sinus-specific health status, including a reduction in symptoms (p < 0.001) and medication usage (p < 0.001). An overall improvement was found in 82% of patients, whereas 11% were worse, and 7% remained unchanged. Measures of general health status demonstrated preoperative decrements in five of eight subscales as compared with the normal population. Six months after surgery significant improvements were noted in six categories (p < 0.05), and most attained near-normative levels. Individuals with asthma demonstrated greater overall improvement in general health status than did other cohorts (p < 0.05). We conclude that patients with chronic sinusitis achieve large improvements in sinusitis-specific quality-of-life measures 12 months after sinus surgery, as well as improvements in general health status.

Adult

New developments in the diagnosis of Kartagener's syndrome.

Kartagener's syndrome is characterized by the clinical triad of bronchitis, sinusitis, and situs inversus. An inherited ultrastructural defect results in ciliary immotility with impaired mucociliary clearance throughout the pulmonary and sinonasal passages. Until recently, the diagnosis of Kartagener's syndrome was made on the basis of a qualitative decrease in the number of dynein arms and subjective abnormalities in other ciliary components on electron microscopy. New investigations, however, have defined objective methods of diagnosis on the basis of quantitative ciliary measurements. The use of these methods in a series of 17 cases of suspected ciliary immotility resulted in a reversal of diagnosis in 6 cases (35%) that previously were considered normal. These results suggest that the prevalence of inherited ciliary dyskinesias is much greater than currently is recognized. The early identification and treatment of individuals with these disorders could lead to a reduction in irreversible sinus and pulmonary pathologic conditions with improved long-term survival.

Biopsy

Endoscopic treatment of sphenoid sinusitis.

Juxtaposed between the posterior nasal cavity and skull base, the diseased sphenoid sinus presents unique challenges when surgical drainage is required. Endoscopic techniques have gained widespread popularity for the treatment of sphenoid sinusitis, yet the efficacy of such treatment remains largely unknown. Thirty-four patients who underwent endoscopic sphenoidotomy were monitored over a period of 6 months to 5 years. Surgery was performed with the superior turbinate used as the key landmark for identification and enlargement of the natural sphenoid ostium. Surgical access was through either a transnasal or transethmoid approach, depending on whether disease was limited to the sphenoid sinus. Prospective analysis of 26 patients with established outcome measures demonstrated a significant reduction in facial pain, nasal drainage, and congestion 6 months after surgery (p < 0.0001). Medication use was also reduced but to a lesser extent (p < 0.05). Endoscopic sphenoidotomy appears to be a safe technique that effectively reduces patient morbidity associated with sphenoid sinusitis.

Adolescent

Holmium:YAG laser endoscopic sinus surgery: a randomized, controlled study.

Although surgical lasers were introduced to the field of otolaryngology more than 20 years ago, their use in rhinologic surgery has remained relatively limited. With the development of the holmium:yttrium-aluminum-garnet (YAG) laser, a device is now available that offers those features necessary for effective sinus surgery:precise bone ablation, efficient soft tissue coagulation, and fiberoptic transmission. This solid-state laser of 2.1-microns wavelength can be coupled with endoscopic instrumentation for the surgical treatment of sinus disease. This study was conducted to determine the clinical efficacy of the holmium:YAG laser for endoscopic sinus surgery. A microscopic analysis of laser-treated sinus tissue was also performed in an attempt to determine the histologic basis of the observed clinical findings. In a prospective, randomized, controlled, single-blinded study, 32 consecutive patients underwent endoscopic sinus surgery using the holmium:YAG laser on one side of the nose and conventional endoscopic instrumentation on the other side. Patients rated symptoms for each side of the nose at 1 week, 1 month, 3 months, 6 months, and 2 years after surgery. Healing parameters were similarly rated by the surgeon. Until the study was completed, patients were not told which side of the nose had been treated with laser surgery. No intraoperative complications occurred. The mean intraoperative blood loss was 24.6 mL less on the laser-treated side of the nose than on conventionally treated side (P < .001). At 1 week after surgery, there was increased mucosal edema on the laser-treated side (P < .01). Crust formation was greater on the conventionally treated side at 1 week and was greater on the laser-treated side at 1 mouth (P < .01). Improvements in symptoms of pain, congestion, and drainage were equivalent for both treatment modalities (P < .001). Microscopic analysis demonstrated the ability of the holmium:YAG laser to remove tissue in relatively thin layers with ablation depths of 260 +/- 8.2 microns, 286 +/- 9.4 microns, and 341 +/- 20.4 microns per pulse at energy levels of 0.5, 1.0, and 1.5 J, respectively. A zone of thermal necrosis extending up to 1 mm beyond the site of laser impact was thought to correlate with the increased postoperative edema observed on the laser-treated side. Endoscopic sinus surgery with the holmium:YAG laser is as effective as nonlaser techniques in relieving the symptoms of chronic sinusitis. Laser surgery offers improved intraoperative hemostasis, but it causes increased postoperative tissue edema. The holmium:YAG laser provides the surgeon with an additional tool for the performance of safe, effective sinus surgery.

Adolescent

Endoscopic orbital decompression under local anesthesia.

Orbital decompression for Graves' disease has traditionally been performed with the patient under general anesthesia. Endoscopic instrumentation allows for removal of the medial orbital wall and floor through an intranasal approach with local anesthetic techniques. Twelve endoscopic orbital decompressions were performed on awake patients with uncovered eyes so that vision could be monitored throughout the procedure. Simultaneous lateral decompressions were performed in 11 cases. No intraoperative or postoperative complications occurred. Visual acuity remained stable or improved in all cases. Proptosis was reduced an average of 5.5 +/- 1.6 mm. In a comparable series of 29 endoscopic decompressions performed with patients under general anesthesia, proptosis was reduced an average of 4.8 +/- 2.0 mm. Endoscopic orbital decompression with patients under local anesthesia appears to be an effective technique that may provide an additional margin of safety in prevention of injury to the optic nerve.

Adult

The health impact of chronic sinusitis in patients seeking otolaryngologic care.

Although chronic sinusitis is an increasingly common diagnosis in the United States, the health burden of this disorder relative to the general population and to other chronic diseases has not been previously evaluated. One hundred fifty-eight patients with chronic sinusitis and no prior surgery underwent cross-sectional evaluation by use of the Medical Outcome Study Short-form 36-Item Health Survey. These patients were all referred for otolaryngologic care, and more than 80% subsequently underwent sinus surgery. Mean scores were compared from the eight subscales of general health assessment with similarly derived data for the United States general population. Significant differences (p < 0.05) were seen in several domains, including bodily pain, general health, vitality, and social functioning. Comparisons with other chronic diseases revealed significantly lower scores (p < 0.05) in measures of bodily pain and social functioning for sinusitis patients than in patients with congestive heart failure, angina, chronic obstructive pulmonary disease, and back pain. These findings suggest that the national health impact of chronic sinusitis is far greater than is currently appreciated.

Adolescent

Techniques for outcomes research in chronic sinusitis.

Accurate assessment of patient outcome after sinus surgery requires the collection of valid and reliable data. Symptom-based surveys were administered in a prospective manner to 104 patients with chronic sinusitis. Test-retest reliability for the Chronic Sinusitis Survey based on duration of symptoms (0.86, P < .0001) was superior to that for a similar survey based on severity of symptoms (0.57, P < .0001). Results of the Chronic Sinusitis Survey also correlated significantly with subscales of a general health assessment in the extent to which chronic sinusitis limits physical activity (0.40, P < .01), interferes with work or other activities (0.36, P < .01), and affects patient perception of bodily pain (0.46, P < .001). The Chronic Sinusitis Survey is an efficient and reliable method to follow health status and health-related quality of life outcomes in patients with chronic sinusitis.

Activities of Daily Living

Endoscopic laser dacryocystorhinostomy.

Endoscopic laser dacryocystorhinostomy (DCR) enables an obstructed lacrimal sac to be opened through an intranasal approach, avoiding the need for a skin incision. The holmium:yttrium aluminum garnet (holmium:YAG) laser is well-suited for this procedure because of its properties of fiberoptic delivery, effective bone cutting, and precise soft-tissue coagulation. Efficient bone ablation is particularly important for primary DCR which requires removal of relatively thick bone along the lateral nasal wall to expose the lacrimal sac. Forty-six endoscopic laser DCRs were performed on 40 patients. There were no intraoperative or postoperative complications. The surgery successfully relieved lacrimal obstruction in 85% of patients. Endoscopic instrumentation allowed for the rapid identification and correction of intranasal causes of DCR failure, including ethmoid sinus disease and middle turbinate hypertrophy. Endoscopic laser DCR appears to be a safe and effective procedure which should be considered as an alternative to external DCR for the surgical treatment of nasolacrimal duct obstruction.

Adolescent

Endoscopic orbital decompression.

Exophthalmos from Graves' disease can result in visual disability and cosmetic deformity. Surgical treatment of this disorder is now possible through an intranasal endoscopic approach that allows removal of the medial orbital wall and floor without an external incision. Endoscopic orbital decompression was performed on 22 orbits in 14 patients for treatment of progressive exophthalmos. Local anesthesia was used in five cases. Sixteen procedures involved a concurrent lateral orbital decompression performed through an external approach. There were no intraoperative or postoperative complications. Visual acuity remained stable or improved in all cases. Proptosis was reduced an average of 3.2 +/- 1.1 mm (range 2 to 4.5 mm) by endoscopic decompression alone. When a lateral decompression was also performed, proptosis was reduced by an additional 2.4 mm, for an average improvement of 5.6 +/- 1.7 mm (range 2 to 8 mm). Endoscopic orbital decompression appears to be a safe technique for the treatment of exophthalmos that can be performed effectively with the patient under general or local anesthesia.

Adult